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Some of the first land plants: Mosses.

Moss in the Grass

David Beeson

So, how do you gardeners rid your lawn of moss? Well, you’ll have to read on to find out!

When life started to emerge from the watery realms it, unexpectedly, was poorly adapted to life on land. Evolution needs time to work its miracle. LOTS of time.

The mosses and liverworts (known as Bryophytes) were the relatives of the algae that made the leap first. Today’s types of bryophytes are very distant relatives of the first terrestrial invaders – and your lawn grass is one of them.

Human sperm and eggs have just a single set of chromosomes – 23 in number. Egg and sperm’s DNA combine to give the two sets, 46 chromosomes, of the normal human.

Mosses (and liverworts) have a similar, but very different, pattern of changes in chromosome numbers. The moss plant you spot in the lawn, growing on a wall or under a woodland canopy has just a single chromosome set. This generates egg or sperm cells which, under WET CONDITIONS, can fuse. However, this zygote (fertilized egg with two chromosome sets) grows in situ on top of the green mossy plant – a spiky, small stem with a bobble (Capsule) on its end. Eventually, this capsule will burst open liberating spores which can grow on your lawn to a new green moss.

Mosses (Liverworts, horsetails and ferns) must have a wet environment at the appropriate time to complete the life cycle. That is not true for conifers or flowering plants … or humans … although a warm beach can be an inducement!

Mosses can never grow big as they contain almost no system for transporting water around the plant … you need to move on to the horsetails and ferns before that happens … which is why they can grow bigger.

The spore capsules contain vast numbers of spores. They are everywhere. On my garden wall these capsules are consumed by goldfinches over the winter. They sit nibbling them off most days.

Mosses do not like really dry conditions – because they cannot reproduce. But, they can survive dehydration for a while, so in the UK are seldom killed off by a hot summer as a wet autumn and winter follows.

Iron sulphate is deadly to mosses. So, lawn sand is a combination of fine sand and iron sulphate. The sand, in theory, carries the iron and lightens the soil. Except, I do not believe the latter unless you add tonnes. Much better to buy the iron sulphate and spread it with a gloved hand. Much cheaper.

Woodland moss without spore capsules

BUT, the soil is full of enough moss spores to grow new plants for fifty years. So, sit back, admire the mosses and do not chuck unwanted iron sulphate to pollute the water supply. ‘Going for the mosses’ is a waste of time and effort.

Mosses show, like ALL land plants, alternation of generations. This is a flipping between an asexually reproducing phase and a sexual phase. In the case of mosses the two are attached, the one parasitic on the other. In other plant types they can be quite separate e.g. ferns.

Gametophyte = green ‘plant-like’ structure. The hair-like sporophyte is composed of seta and capsule (with its spores).

The gametophyte is haploid (each cell has only one set of chromosomes), the sporophyte is diploid (like us) and each cell has two chromosome sets but reduces that number in the spores via a nuclear division called meiosis.

Image result for moss life cycle diagram

I often spot goldfinches eating the spore capsules, but not the green gametophyte.

A similar life cycle occurs in liverworts.

In ferns, horsetails, conifers and angiosperms (flowering plants) the sporophyte is the dominant plant (what you normally see) and the gametophyte is much reduced. In flowering plants there are ‘male’ (Pollen, released) and ‘female’ spores (not released) and they germinated to form the gametophytes. The gametophyte has two forms: 1) Male spores grows into the germinated pollen (Pollen tube) or 2) the ovule containing an egg cell that is held within the carpel of the flower. All very confusing! Get a good botany book and check it all out. (Buy a second hand ex-uni library copy for just a small amount of money! The material will be bang up-to-date … it doesn’t change.)

Image result for angiosprm life cycle

A Journey to the Jade Sea

(Now called lake Turkana)

Aspects of Africa 1 – The El Molo of Kenya

David Beeson July 2022

In 1998 our family spent some time exploring Kenya for the first time. Perhaps one of the most interesting journeys was to the far north-east of the country, to Lake Turkana, beyond the lands of the Samburu Tribe. It is remote, very remote and we drove for many hours seeing no other vehicles, and sometimes not even seeing the road – we just headed in the right direction across volcanic larva fields.

We had first spotted the area from a plane heading to Malawi. We had been in the cockpit when Annette asked, “What’s that lake?” The friendly pilot searched for an ancient atlas and responded, “Lake Rudolf”, as it was once called. Now it is now called Lake Turkana and is proudly the world capital for Nile crocodiles – over 14 000. , It is the world’s largest permanent desert lake and is semi-saline with no outlet to the sea and 1cm of evaporation daily. It, indeed, has had a third name, The Jade Sea. (See the book at the end.)

Maralal lady
Maralal

The rocks in the surrounding area are predominantly volcanic. The Central Island reserve is an active volcano, emitting vapour. Outcrops and rocky shores are found on the east and south shores of the lake, while dunes, spits and flats are on the west and north, at a lower elevation. It is very dry and conventional agriculture is utterly impossible.

On-shore and off-shore winds can be extremely strong, as the lake warms and cools more slowly than the land. Sudden, violent storms are frequent. Three rivers (the Omo, Turkwel and Kerio) flow into the lake, but lacking outflow, its only water loss is by evaporation. The lake’s volume and dimensions are variable. For example, its level fell by 10 m (33 ft) between 1975 and 1993. However, it now has increased in size by 10% and many surrounding areas have been flooded, with villages being isolated or destroyed.

Lake Turkana

A new dam is in prospect in neighbouring Sudan which will divert water to irrigation schemes. This will impact a tragically poor community even futher.

Our journey to Turkana, from Nairobi, took several days, first stopping at lake Baringo before hitting the wild, remote northern Kenyan country.

Maralal was dry, even though we arrived in August. The town was lively with proud and aloof people dressed often in red, stripped clothes. Most locals were reluctant to be photographed, but some Kenyan shillings turn a few peoples’ minds.

With desert-like vegetaion the countryside felt unproductive, although the acacia trees had fearful spines that even penetrated my shoes and the Landcruiser’s tyres. Ostriches, Grant’s gazelles and zebra were around, as were large bateleur eagles.

Our road north

Eventually, the ‘road’ defeated the vehicle. Three attempts to drive up the stream bed’s side failed, until a winch (and shedding the human cargo) supplied enough pull to reach the top. At times the Landcruiser travelled at about 1kph for long periods.

Despite the remoteness, people were around. Camel herders and tribally-dressed men could be spotted sitting under bushes. Of volcanic cones there were dozens, with a count of 50 in one location.

 As one could reasonably expect, camping was basic and had its interesting side. One night, at Baringo, we had hippos trotting and grunting past our tents, and near South Horr we had a fully dressed Samburu warrior, complete with spear, squatting outside the tent all night for our protection. (No loo trips that night!) The long-drop loos here were yet another experience, with their embedded wildlife interesting and very mobile. But, at our lake venue we had our own huts, complete with a 30cm lip in the entrance. Why? To stop Nile crocodiles wandering inside.

Our lakeside hotel

At our lakeside camp, we swam inside a crocodile-proof enclosure but other activity was impossible for us due to the heat.

Near Baringo. Klipspringers.

Along the lake shore we encountered nomadic herdsmen with flocks of camels and goats, plus a few donkeys and, surprisingly, sheep.

A further issue on our exploration was that the Samburu and Rendille tribes were killing each other, each currently accusing the other of cattle rustling. This stopped us visiting the main settlement of Loyangalani.

Yes, this is the El Molo village
Annette and locals

We were picked up from our lake campsite and taken to the El Molo village. Spotting cormorants, shags, pelicans, white and goliath herons, Egyptian geese, plovers and African skimmers from the powered boat. Distant views were had of timid crocodiles, which are locally hunted for food. Around the settlement were grey-headed gulls, kori bustards, sand grouse and various hornbills.

The photographs give a feel for the village, but not the overriding smell of fish and a ground covered in fish scales. Inside, the hunts were basic with a bed, three stones to contain a wood fire (wood collected many kilometres away and carried back by the women) and a metal cooking pot. Clothes and other resources were virtually absent. There was a communally-owned maize grinding machine; the maize being donated by the USA.

Despite their basic construction, with a lack of rainfall the locals told us the buildings were long-lasting.

El Molo village
Colourful women
El Molo villagers
El Molo villagers

The tribal dead were ‘buried’ by placing stones over the body as digging was impossible.

The El Molo live in an impossibly remote location and their population was mainly found in two villages of 150 and 70 residents. The whole tribe is no greater than 1100, and its integrity is being diluted by marriage and its unique language is nearly extinct.

My Lonely Planet says of the Jade Sea – ‘Top the ridge here and therein is in front of you – The Jade Sea. It’s a breathtaking sight – vast and yet apparently totally barren. Youll see nothing living here except a few brave, stunted thorn trees. When you reach the lake shore, you’ll know why – it’s a soda lake and, at this end, highly saline.’ Of the El Molo village there is no mention.

See: Journey to the Jade Sea, by John Hillaby. This is only available second-hand and is historic, but recommended.

We had been in the cockpit viewing Lake Turkana when we spotted Mount Kilomanjaro… and the pilot flew all around it so we could view it from all sides. That would not happen today.

There is an article about the El Molo in the Guardian. See website for 1st February 2022/

Some wildlife in South Wales

David Beeson June 2022

Annette and I embarked on a two-week exploration of the coastline at the start of June. Our first stop was just west of Newport at the Tredegar House caravan site. This allowed easy access to The Newport Wetlands which are partly managed by the RSPB and dominated by present and past electricity generation.

Bee orchid with yellow rattle behind.

The Newport Wetlands trail guide is available: https://www.rspb.org.uk/globalassets/downloads/documents/reserves/newport-wetlands-trail-guide.pdf

Overlooking the Newport Wetlands are two power stations. On the right is the unused coal station and on the left the gas power station.

As is often the situation in the UK, the site is reclaimed from industry. Any elevated sites (and there are many) have been built up with coal ash from the adjacent, but defunct, coal-fired power station. Even the wetland ponds were once slurry pits; despite that, they hold some interesting wildlife.

In places the ash is so toxic that even basic plants fail to thrive.

Reedbeds, grassy wetlands and estuarine habitats are here. There are 16 species of dragonfly, rare bees and an abundance of butterfly and day-flying moths, while stoats and weasels are often encountered … but not for us. Water shrews are here, too, but are mostly nocturnal and always challenging to spot.

Grass snake

The RSPB staff mainly deal with school groups, yet are a fund of knowledge and we were pointed to a huge heap of reed-cuttings just 100m from the entrance. Several large grass snakes were basking there despite the cool summer conditions. Most likely, the pile would serve as an incubation pile for their leathery eggs. Yet not all the snakes have it so easy, one went, with considerable difficulty, down the throat of a grey heron!

Grey Heron

With only one hide and limited access to the waterways, the animal wildlife has the place to itself. With it being summer, waterfowl were in low numbers, but grebes, moorhens and mute swans were easily seen. A single male marsh harrier quartered the extensive reedbeds, and buntings and warblers played us their songs. Bearded tits are common here.

Gadwall

Even before we passed the entrance there were orchids on display: bee and southern marsh orchids being common. Overall, there are five orchid species here.

Overall, an interesting location but hardly worth a full journey in summer. As a local excursion, it offers plenty.

We headed west.

The Gower

The Gower Peninsular is spectacular scenery. It is a chunk of limestone dumped onto the bottom of Wales, just west of Swansea. About 70 square miles (180 km2) in area, Gower is known for its coastline, popular with walkers and outdoor enthusiasts, especially surfers. It was the UK’s first AONB (Area of Outstanding Natural Beauty), which gives it mild planning protection.

The north-coast is estuarine and is dominated by salt marsh and cockle beds, with plant-rich sand dunes in the south-west. The south coast is a delightful combination of rocky bays, sandy beaches and sand dunes. The east is a conurbation and we failed to sample it.

Penrice Castle

Inland are stone-walled small fields, some dating back to Medieval times, and open common land. Stone-built castles abound here.

Woodland is limited, and those open are infested with dog walkers who seem unable to control their barking and unpleasant hounds. Grab a heavy stick if you wish … we were attacked by three dogs and were shaken by the experience.

St Illtyd’s Chuch in Oxwich woods. It dates back to C6 … 500s AD.

The best wildlife locations: Cym Ivy sand dunes near Llanmadoc (Britannia Inn for an evening meal is worth exploring) – look out for marsh helleborines in the wet areas and sea holly near the coast; Worms Head for nesting seabirds, kestrels and coughs. Oxwich National Nature Reserve offers yellow rattle and several orchids, plus a healthy adder population. Oxwich Wood, just south of the village, is a woodland I’d love to own. It is rich in ferns and its slope gives it a challenging format.

Botanic Gardens

For a spectacular hay meadow visit the wonderful Welsh Botanic Gardens. We encountered thousands of greater butterfly, spotted and southern marsh orchids. A stunning site overall as they have incorporated wild planting whenever possible. A real must-visit in June.

However, the Llanelli Wetlands, Wildfowl and Wetlands Organisation, was too much a smelly zoo for us. Perhaps it would offer more in winter when the migration of northern bird species would add some attraction.

Worms Head
A stonecrop clings to the sand.
Sand dune with pyramidal orchids
Sea bindweed

How well do you know your birds? A Bird Anatomy and Physiology Quiz, 1.

David Beeson, June 2022

ANSWERS WILL BE IN A SEPARATE POST … so, you cannot cheat here!

QUESTION ONE

Name the three types of feathers on a typical bird, such as a sparrow.

QUESTION TWO

In mammals, skin hair cells have muscles attached to change their orientations. For example, when they are cold. Does this happen in birds?

QUESTION THREE

Do feathers have a blood supply?

QUESTION FOUR

There is an old music hall song claiming that a thrush has 40 000 feathers. How many feathers are there on a wintering swan (the highest number I know)? a) 1 000, b) 20 000, c) 40 000 or d) 100 000.

QUESTION FIVE

Is it true that the change from winter plumage to summer, breeding, plumage is often achieved by the abrasion of the end of the feathers?

QUESTION SIX

When humans tan, it is caused by the production of melanin in the skin. Do birds make melanin?

QUESTION SEVEN

How long do feathers last on a golden eagle?

QUESTION EIGHT

What are the ‘wish bones’ of a bird?

QUESTION NINE

The keel of a bird’s skeleton is long and strong for the attachment of the main flight muscles, but penguins do not fly. Do penguins have a keel attached to their ribs and sternum (breast bone)?

QUESTION TEN

All mammals, including the giraffe, have seven neck vertebrae. Is there a similar number in birds?

Bird Quiz, the Answers

David Beeson, June 2022

ONE

There are three basic feather types: 1) The PRIMARY FEATHERS which provide the left in flying, 2) CONTOUR FEATHERS that often have a more downy lower part and 3) DOWN FEATHERS that are for controlling body temperature – the bird’s underwear!

Down feathers can be plucked in birds such as the wider to provide insulation within the nest. Some of these feathers break off at the tip to yield a fine powder – especially in herons.

Some parts of a bird’s body may lack feathers. The brood pouch being an example.

Obviously, feathers are not randomly spread over a bird’s body. Each type grows in specific locations.

There are feather types intermediate between contour and down feathers.

TWO

Each feather can be moved separately by muscles within the skin, even though the feather is dead at maturity.

THREE

Feathers are unique to birds, each consisting of a tapering shaft (Rachis) bearing a flexible vane on each side. The short basal part of the feather (Calamus) is round in section and is almost hollow. During growth, it has a blood supply but that is sealed off at maturity, leaving a non-metabolising structure. It is dead.

FOUR

Feather numbers vary from just under 1000 in some hummingbirds, to over 25 000 in wintering swans. In most birds the feathers contribute 15 to 20% body weight.

FIVE

Feathers often change colour by abrasion, with the ends being rubbed off during use. The change from winter to summer plumage is said to be often achieved in this way rather than growing new feathers which would be resource demanding.

SIX

Feather colours are produced by a combination of relatively few pigments – melanins, which the bird manufactures, and carotenoids giving the yellows and reds. The latter are from the diet. Of course, flamingoes lose their pink colour when deprived of their natural placktonic diet.

Additional colours by microscopic prisms of wax (sort of!) which refract light and generate the colours on birds such as the UK kingfisher.

SEVEN

Birds usually moult their feathers once a year. Golden eagles keep some of their feathers for two years.

EIGHT

The wish bone is equivalent to our collar bones, the clavicle.

NINE

Penguins swim with their wings, so have a keel.

TEN

Having lost their fore-limbs to flight evolution has given birds many more neck bones – 11 to 25. This gives them a flexible neck capable of reaching most parts of the body.

The Physiology of Birds, 1. (How birds work)

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Free knowledge.

David Beeson, May 2022

While nearly everyone you meet on a nature exploration can identify most of the birds they encounter, few know much about how they work. This article is an introduction to some aspects of their physiology.

For those who require more detail, you should obtain: Handbook of Bird Biology (Cornell Lab of Ornithology) and see the chapter on Physiology.

Notice, no diaphragm or division of the body cavity into thorax and abdomen.

Supplying oxygen to flight muscles

Flight is a high energy-demanding activity. Birds use the energy in wind to reduce this requirement, yet even getting off the ground can be difficult … as I found out attempting the high jump at school!

Human ventilation works by drawing oxygen-rich air into the lungs using the diaphragm and inter-rib muscles. This air goes into the small sac-like alveoli of the lungs, where oxygen is exchanged for carbon dioxide. Expiration expells that air back into the environment. Of the 20% oxygen in the incoming air only around 4% is taken up by the lungs; an efficiency of around 20%. Now, when I achieved that percentage in examinations I was not proud! This method is insufficient for a high-energy demand such as flight.

The human gas exchange system is in Diagram B below. (Blue is air, red blood.)

In A, the bird lung, there is no mixing of input and output gases, and that is much more efficient, so much more suited to an aerial life-style.

Human lungs involve input and output air mixing. Not so in birds.

Birds avoid the mixing problem by moving air through their lungs in one direction via a series of 7 to 9 air sacs, connected by loopy tubes. Birds take oxygen into their body tissues when they breathe in and when they breathe out. So, for every bird breath, humans would need to take two. Effectively, air flows continuously through a bird’s lungs, while in the human it pulsates.

Birds do not have a diaphragm and the lungs do not flex as in humans. Instead, the air sacs change volume and act as bellows, and these sacs are spread around the body. The whole body cavity, not just the pleural (lung) cavity, changes in volume during breathing.

Bird lungs and air sacs occupy twice the comparative body volume in birds to humans, while their lung is smaller. The reasons are clear: flying is very oxygen demanding, they have a higher body temperature (42 compared to 37 Celsius) and need to fly above ground level where the percentage of oxygen is reduced.

Note movement of sacs.

To cope with the high oxygen demands of flight the heart rate needs also to be enhanced, so birds typically have larger hearts than mammals of similar sizes, and they also have much higher heart rates with resting heart rates generally sitting between 150-350 beats per minutes for a medium-sized bird. (Humans 60 – 70bpm). The capacity for lung O2 diffusion is also greater in birds because of the exceptional thinness and large surface area of the gas exchange tissue. Nevertheless, the diffusion barrier appears to be mechanically stronger in birds than in mammals, so pulmonary blood flow and pressure can increase without causing stress failure.

So, with a one-way airflow, high volume of blood arriving at the thin gas exchange surfaces and high heart rate (8 times higher during flight) the natural flow of oxygen from the incoming air by diffusion is high. Coupled with this, avian blood has a greater capacity to take up and deliver oxygen to the body tissues.

Interestingly, birds with long necks have to take deeper breathers than those with shorter necks, as there will be more ‘dead space’ of air that does not reach the lung’s gas exchange surfaces.

Yet there is even more efficiency in the system. Avian muscle fibres are smaller than those of mammals, ensuring the easier movement of gases into and out of those highly metabolic tissues. And their nervous system is less vulnerable to high carbon dioxide levels.  All of this allows the system to cope with the demands of their lifestyle.

Surface area to volume

Organisms gain or lose heat from their outer surfaces. They can, if it is kept moist, use their outer surface for the exchange of gases.

Imagine cubical animals:

size1 x 1 x 1 Small organism2 x 2 x 210 x 10 x 10 Larger organism
volume181000
Surface area624600
Surface area to volume ratio6 : 13 : 10.6 : 1
commentEasy exchange of gases over their comparatively large surface, BUT easy heat gain or loss. Gas exchange through the surface will be difficult BUT heat loss or gain is less significant. Needs a gas exchange organ – lung.
Effect of size on an organism’s metabolism

As organisms increase in size they need specialised organs (internal and moist) to take up and release waste gases, but heat control is easier.

Smaller organisms have a comparatively large surface area to volume, so gas exchange is easier. Yet, small warm-blooded organisms are in danger of losing too much heat as there is little body volume to generate heat through their metabolism.

Consider a minute aquatic organism such as Amoeba. From the data above one can suspect that diffusion through its surface could supply sufficient exchange of gases (O2 and CO2). It is unconcerned, mostly, by gain and loss of heat. However, a small bird living in a cool or cold environment, not exchanging gases through its outer layer, is in trouble because of potential heat loss with its comparatively large surface area when compared to a much bigger bird. Hence why small hummingbirds must hibernate at night. (But not larger birds). With such losses of heat, the energy intake of a small bird needs to be much greater (for each unit of weight) than a larger animal. Little birds seldom ‘enjoy’ cold climates and may force some to migrate.

Feathers are vital not only to aid flight but also for thermoregulation. They may need to trap insulatory air to reduce heat loss or gain. So, not all feathers are flight feathers, some are ‘down’ feathers, and their percentage and orientation will vary with environmental conditions. Maintaining feathers in optimal condition is a vital activity.

Energy source

The figures usually quoted for the energy content of fats (lipids) and carbohydrates is 38KJ to 17KJ a gramme. A gramme of fat contains about twice the energy than carbohydrate. If birds need to have high energy stores, e.g. for migration, it is better to use fats. Migratory geese have higher fat stores than chickens (non-migratory) and will need to use it in energy release during migration.

Fats may be great energy stores, yet they metabolically need more oxygen than carbohydrates, and with high-flying migratory birds, this introduces a new problem. At high altitudes air pressure is lower, so lift is less. Hence greater flapping is needed at a time when oxygen levels are lower than at ground level. Under such conditions, birds risk going anaerobic with carbon dioxide levels causing body stress or death. Flying high may reduce air resistance and allows the chance to use back winds to aid you, but other negative factors come into play.

Birds, such as the high-flying, migrating Bar-headed Geese, take much deeper breaths and have larger lungs to cope with the low oxygen levels. Additionally, like high-living mammals, they possess blood haemoglobin that takes up oxygen more readily than a non-migratory species. Also, the goose heart’s left ventricle is more enriched with blood vessels to reduce the chance of it being oxygen-deficient. There are cellular modifications too to make oxygen usage more efficient.

Of course, we all know that the muscles of birds use one of two systems. Explosive muscles work mainly anaerobically (white meat), while slowly working muscles use oxygen (red meat). Red meat contains the fixed oxygen-holding pigment myoglobin which is absent in white meat.

The explosive-functioning muscles are to fly from predators, yet they soon become oxygen-deficient and exhausted. This is ideal for wild chickens and turkeys that are ground-dwelling and burst upwards but coast down to a safer location. Their leg muscles are functioning much of the time so will be red meat. However, those explosive muscles are not the correct design for migratory birds and they need slower but longer-lasting red muscle.

Birds are wonderful examples of how evolution adapts a basic animal design to many different niches – environmental options.

Plant Families

David Beeson, May 2022

If you are a subscriber and receive all the articles, do look at the NEW HOMEPAGE at http://www.nwhwildlife.org as all the posts have been reorganised to make searching easier.

The placing of organisms into groups some people think is a rather boring topic. I agree; yet understanding some aspects of classification makes life and studying organisms easier and rewarding.

Organisms in any group have features in common and possibly a common ancestor. I’m in a group: I follow Southampton Football Club and that is the common feature of Saints Supporters (as we are called). My ancestory was being brought up near the city of Southampton.

The PLANT KINGDOM has sub-sections (Divisions): liverworts, club mosses, hornworts, ferns, ginkgos, cycads, conifers and flowering plants (monocotyledonous and dicotyledonous groups).

(Sadly, not all botanists agree how to subdivide the plant kingdom … which makes it near impossible for everyone else.) (NOTE, if you are studying botany at degree level, stick to whatever system your professors says! She / he will be marking your examination scripts!)

Here, we will look only at the flowering plants and their FAMILIES.

When ‘in the field’ I often need to identify a plant. With most ID books using the plant family (rather than flower colour or plant size or habitat) to organise their system, knowing the family saves much effort.

Many people become confused with plant families. And, it is understandable as seldom is it explained.

The flowering plants – the Angiosperms.

These are plants that flower and have seeds produced in fruits. The seed being an immature plant consisting of a minute root, shoot, stem and one or two seed leaves – cotyledons. A fruit is produced from the ovary of the plant*. (Gymnosperms have seeds, but they are not contained within an ovary – gymnosperm = naked seeds …. as they are found on the surface of an open cone, so naked.)

[*What is the true definition of a fruit? A fruit is a mature, ripened ovary, along with the contents of the ovary.]

In my opinion, there are two sub-groups of the Angiosperms – the monocotyledonous plants (monocots) with one cotyledon in the seed, and the dicotyledonous plants (dicots for short) with two.

  • Monocots usually have leaf veins that run parallel and flower petals / sepals in multiples of threes.
  • Dicots have netted leaves and flower sepals / petals in combinations of four or five.

Plant families are decided on their flower structure. Size is of no consequence. Flower colour is of no consequence. Members of a plant family may be trees, shrubs or herbaceous, it makes no difference – it is flower structure that is crucial.

So, which floral features are important?

  • The number of floral parts i.e. how many petals or sepals?
  • Are the sepals coloured and look like the petals?
  • Do the petals all join to form a corolla?
  • Is the ovary above the junction of petals meet with the flower stem (superior ovary) or below it (inferior ovary)?
  • How many flowers are there on a flower stem and how are they organised?  
  • Etc.
The pistil is also called the carpel. Superior ovary is shown.
The receptacle can be below the female parts (Gynoecium is an alternative name for pistil / carpel), surround it or enclose it.
No one said flower structure was easy!

Firstly, recall that flowers are in layers. The bottom layer comprises the sepals; next petals, then stamens and carpels at the top. They all join to the receptacle that sits atop the flower stalk. The receptacle can surround the carpels.

Orchid flower diagram – concentrate on sepals and petals and ignore the rest.

For example, the Orchid Family.

They all have parallel leaf veins, so are monocots and seeds have a single cotyledon. There are no dicot orchids.

Floral parts (sepals and petals) are in threes, but in a specific arrangement. The three sepals are at the top and sides. Two petals form a hood, while a large petal flows down at the front. That package is only found in the orchids.

Even parasitic orchids, with no green parts and brown flowers, have that structure.

UK wild orchids and exotic orchids from Costa Rica have the same structure.

Now perhaps go to your plant ID book, your flora, and skip through the pages to see the different plant families and seek out their characteristics (Often stated in the introduction to that family).

I do not know all the families … in fact, not even near! But, the more often I ID a plant the more families I start to understand.

Remember: eBay offers secondhand botany books at almost zero cost. They do not go out of date easily. That’s where my uni-level books come from.

The New Forest National Park in April

David Beeson

I grew up not far from The Forest, as we called it. It was only later, when I had travelled the World, did I understand just how special it is. Lowland heath, its ecological label, is rare … really rare, so its plants and animals are treasures. It was first a royal hunting estate, after 1066, and its resident villagers were dispersed. Yet, with poor, sandy and gravel soils it must have been hard work to eke out a living there. Today, the surrounding population, within an hour’s drive, is large – Bournemouth and Poole, Eastleigh and Romsey, Southampton, Fareham, Gosport and Portsmouth. Their residents flock to this open space and many have loose dogs that are the curse of wildlife and wild areas. Even the dog poo is changing the ecology with extra nitrogen and an acidification of the pH.

Belatedly, the authorities are finally closing car parks and restricting ad-hoc parking along roads and lanes. ‘Full’ signs are needed on some days.

Annette and I took our caravan to near Brockenhurst, having booked our spot nine months ago. Once there we walk and gently explore, yet this time it was for me to lead a field trip.

I lead a U3A group called Flora and Fauna, and we aim to generate data for conservation organisations. This time, however, it was just a learning exercise.

Netting is to stop birds of prey from capturing the reptiles.

The first location was the Reptile Centre, which was opened specially for us, and the lead forester taught the group about the UK’s reptiles (see the previous article). The ultra-rate Smooth Snake was the star, and we saw the adders, slow worms and green lizards. Later in the day, a mature male adder wandered across our routeway to re-enforce its design and beauty.

Male adder.
Male and female
First year adder – 9 months old.

The Oak Inn at Bank delighted our hunger at lunch, before we headed into the mature forestry areas for woodland ecology.

One, of many, North-American Douglas Firs planted in the 1800s.
The ling-zone on the transect

Finally, a line transect was completed from wet heath to dry heath, looking only at three heathers: cross-leaved heath, ling and bell heather. The % cover, just to the nearest 10%, was recorded along a 90m line. The data clearly showed the plants’ niches. Cross-leaved heath is a damp-lover, bell heather only lives in the dryest locations and ling is the one that is tolerant of both conditions.

Our next excursion is to record orchids and butterflies for a conservation group and the UK Army on Salisbury Plain.

YOU SHOULD READ THIS ————-SOIL – an article from the UK GUARDIAN newspaper.

From David: Worth reading. The author is a well-known environmentalist. The newspaper is straight and factual (unlike some others).

Don’t dismiss soil: its unknowable wonders could ensure the survival of our species

by George Monbiot

Sat 7 May 2022 09.00 BST

Beneath our feet is an ecosystem so astonishing that it tests the limits of our imagination. It’s as diverse as a rainforest or a coral reef. We depend on it for 99% of our food, yet we scarcely know it. Soil.

Under one square metre of undisturbed ground in the Earth’s mid-latitudes (which include the UK) there might live several hundred thousand small animals. Roughly 90% of the species to which they belong have yet to be named. One gram of this soil – less than a teaspoonful – contains around a kilometre of fungal filaments.

When I first examined a lump of soil with a powerful lens, I could scarcely believe what I was seeing. As soon as I found the focal length, it burst into life. I immediately saw springtails – tiny animals similar to insects – in dozens of shapes and sizes. Round, crabby mites were everywhere: in some soils there are half a million in every square metre.

Then I began to see creatures I had never encountered before. What I took to be a tiny white centipede turned out, when I looked it up, to be a different life form altogether, called a symphylid. I spotted something that might have stepped out of a Japanese anime: long and low, with two fine antennae at the front and two at the back, poised and sprung like a virile dragon or a flying horse. It was a bristletail, or dipluran.

As I worked my way through the lump, again and again I found animals whose existence, despite my degree in zoology and a lifetime immersed in natural history, had been unknown to me. After two hours examining a kilogram of soil, I realised I had seen more of the major branches of the animal kingdom than I would on a week’s safari in the Serengeti.

But even more arresting than soil’s diversity and abundance is the question of what it actually is. Most people see it as a dull mass of ground-up rock and dead plants. But it turns out to be a biological structure, built by living creatures to secure their survival, like a wasps’ nest or a beaver dam. Microbes make cements out of carbon, with which they stick mineral particles together, creating pores and passages through which water, oxygen and nutrients pass. The tiny clumps they build become the blocks the animals in the soil use to construct bigger labyrinths.

Soil is fractally scaled, which means its structure is consistent, regardless of magnification. Bacteria, fungi, plants and soil animals, working unconsciously together, build an immeasurably intricate, endlessly ramifying architecture that, like Dust in a Philip Pullman novel, organises itself spontaneously into coherent worlds. This biological structure helps to explain soil’s resistance to droughts and floods: if it were just a heap of matter, it would be swept away.

It also reveals why soil can break down so quickly when it’s farmed. Under certain conditions, when farmers apply nitrogen fertiliser, the microbes respond by burning through the carbon: in other words, the cement that holds their catacombs together. The pores cave in. The passages collapse. The soil becomes sodden, airless and compacted.


But none of the above captures the true wonder of soil. Let’s start with something that flips our understanding of how we survive. Plants release into the soil between 11% and 40% of all the sugars they make through photosynthesis. They don’t leak them accidentally. They deliberately pump them into the ground. Stranger still, before releasing them, they turn some of these sugars into compounds of tremendous complexity.

Making such chemicals requires energy and resources, so this looks like pouring money down the drain. Why do they do it? The answer unlocks the gate to a secret garden.

These complex chemicals are pumped into the zone immediately surrounding the plant’s roots, which is called the rhizosphere. They are released to create and manage its relationships.

Soil is full of bacteria. Its earthy scent is the smell of the compounds they produce. In most corners, most of the time, they wait, in suspended animation, for the messages that will wake them. These messages are the chemicals the plant releases. They are so complex because the plant seeks not to alert bacteria in general, but the particular bacteria that promote its growth. Plants use a sophisticated chemical language that only the microbes to whom they wish to speak can understand.

When a plant root pushes into a lump of soil and starts releasing its messages, it triggers an explosion of activity. The bacteria responding to its call consume the sugars the plant feeds them and proliferate to form some of the densest microbial communities on Earth. There can be a billion bacteria in a single gram of the rhizosphere; they unlock the nutrients on which the plant depends and produce growth hormones and other chemicals that help it grow. The plant’s vocabulary changes from place to place and time to time, depending on what it needs. If it’s starved of certain nutrients, or the soil is too dry or salty, it calls out to the bacteria species that can help.

A magnifying glass above soil, with grass and a worm underneath it
Soil is the most neglected of major ecosystems. Photograph: Liz McBurney/The Guardian

Take a step back and you will see something that transforms our understanding of life on Earth. The rhizosphere lies outside the plant, but it functions as if it were part of the whole. It could be seen as the plant’s external gut. The similarities between the rhizosphere and the human gut, where bacteria also live in astonishing numbers, are uncanny. In both systems, microbes break down organic material into the simpler compounds the plant or person can absorb. Though there are more than 1,000 phyla (major groups) of bacteria, the same four dominate both the rhizosphere and the guts of mammals.

Just as human breast milk contains sugars called oligosaccharides, whose purpose is to feed not the baby but the bacteria in the baby’s gut, young plants release large quantities of sucrose into the soil, to feed and develop their new microbiomes. Just as the bacteria that live in our guts outcompete and attack invading pathogens, the friendly microbes in the rhizosphere create a defensive ring around the root. Just as bacteria in the colon educate our immune cells and send chemical messages that trigger our body’s defensive systems, the plant’s immune system is trained and primed by bacteria in the rhizosphere.

Soil might not be as beautiful to the eye as a rainforest or a coral reef, but once you begin to understand it, it is as beautiful to the mind. Upon this understanding our survival might hang.


We face what could be the greatest predicament humankind has ever encountered: feeding the world without devouring the planet. Already, farming is the world’s greatest cause of habitat destruction, the greatest cause of the global loss of wildlife and the greatest cause of the global extinction crisis. It’s responsible for about 80% of the deforestation that’s happened this century. Of 28,000 species known to be at imminent risk of extinction, 24,000 are threatened by farming. Only 29% of the weight of birds on Earth consists of wild species: the rest is poultry. Just 4% of the world’s mammals, by weight, are wild; humans account for 36%, and livestock for the remaining 60%.

Unless something changes, all this is likely to get worse – much worse. In principle, there is plenty of food, even for a rising population. But roughly half the calories farmers grow are now fed to livestock, and the demand for animal products is rising fast. Without a radical change in the way we eat, by 2050 the world will need to grow around 50% more grain. How could we do it without wiping out much of the rest of life on Earth?

Man walking up a huge pile of soya in a grain storage barn on a large farm in Brazil
Without a radical change in the way we eat, by 2050 the world will need to grow around 50% more grain. Photograph: Phil Clarke Hill/Corbis/Getty Images

Just as farming is trashing crucial Earth systems, their destruction threatens our food supply. Sustaining even current levels of production might prove impossible. Climate breakdown is likely, on the whole, to make wet places wetter and dry places drier. One more degree of heating, one estimate suggests, would parch 32% of the world’s land surface. By the middle of this century, severe droughts could simultaneously affect an arc from Portugal to Pakistan. And this is before we consider the rising economic fragility of the global food system, or geopolitical pressures, such as the current war in Ukraine, that might threaten 30% of the world’s wheat exports.

It’s not just the quantity of production that’s at risk, but also its quality. A combination of higher temperatures and higher concentrations of CO2 reduces the level of minerals, protein and B vitamins that crops contain. Already, zinc deficiency alone afflicts more than a billion people. Though we seldom discuss it, one paper describes the falling concentrations of nutrients as “existential threats”.

We might barely detect the loss of a soil’s resilience until, when drought strikes, fertile lands turn to dustbowls

Some crop scientists believe we can counter these trends by raising yields in places that remain productive. But their hopes rely on unrealistic assumptions. The most important of these is sufficient water. The anticipated growth in crop yields would require 146% more fresh water than is used today. Just one problem: that water doesn’t exist.

Over the past 100 years, our use of water has increased six-fold. Irrigating crops consumes 70% of the water we withdraw from rivers, lakes and aquifers. Already, 4 billion people suffer from water scarcity for at least one month a year and 33 major cities, including São Paulo, Cape Town, Los Angeles and Chennai, are threatened by extreme water stress. As groundwater is depleted, farmers have begun to rely more heavily on meltwater from glaciers and snowpacks. But these, too, are shrinking.

A likely flashpoint is the valley of the Indus, whose water is used by three nuclear powers (India, Pakistan and China) and several unstable regions. Already, 95% of the river’s flow is extracted. As the economy and the population grow, by 2025 demand for water in the catchment is expected to be 44% greater than supply. But one of the reasons why farming there has been able to intensify and cities to grow is that, as a result of global heating, glaciers in the Hindu Kush and the Himalayas have been melting faster than they’ve been accumulating, so more water has been flowing down the rivers. This can’t last. By the end of the century, between one- and two-thirds of the ice mass is likely to have disappeared. It is hard to see this ending well.

Crops being irrigated near Bakersfield, Kern County, California, US
Irrigating crops consumes 70% of the water we withdraw from rivers, lakes and aquifers. Photograph: Citizens of the Planet/UCG/Universal Images Group/Getty Images

And all this is before we come to the soil, the thin cushion between rock and air on which human life depends, which we treat like dirt. While there are international treaties on telecommunication, civil aviation, investment guarantees, intellectual property, psychotropic substances and doping in sport, there is no global treaty on soil. The notion that this complex and scarcely understood system can withstand all we throw at it and continue to support us could be the most dangerous of all our beliefs.

Soil degradation is bad enough in rich nations, where the ground is often left bare and exposed to winter rain, compacted and wrecked by overfertilisation and pesticides that rip through its foodwebs. But it tends to be even worse in poorer nations, partly because extreme rainfall, cyclones and hurricanes can tear bare earth from the land, and partly because hungry people are often driven to cultivate steep slopes. In some countries, mostly in Central America, tropical Africa and south-east Asia, more than 70% of the arable land is now suffering severe erosion, gravely threatening future production.

Climate breakdown, which will cause more intense droughts and storms, exacerbates the threat. The loss of a soil’s resilience can happen incrementally and subtly. We might scarcely detect it until a shock pushes the complex underground system past its tipping point. When severe drought strikes, the erosion rate of degraded soil can rise 6,000-fold. In other words, the soil collapses. Fertile lands turn to dustbowls.

Some people have responded to these threats by calling for the relocalisation and de-intensification of farming. I understand their concerns. But their vision is mathematically impossible.

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A study in the journal Nature Food found the average minimum distance at which the world’s people can be fed is 2,200km. In other words, this is the shortest possible average journey that our food must travel if we are not to starve. For those who depend on wheat and similar cereals, it’s 3,800km. A quarter of the global population that consumes these crops needs food grown at least 5,200km away.

Why? Because most of the world’s people live in big cities or populous valleys, whose hinterland is too small (and often too dry, hot or cold) to feed them. Much of the world’s food has to be grown in vast, lightly habited lands – the Canadian prairies, the US plains, wide tracts in Russia and Ukraine, the Brazilian interior – and shipped to tight, densely populated places.

As for reducing the intensity of farming, what this means is using more land to produce the same amount of food. Land use is arguably the most important of all environmental issues. The more land farming occupies, the less is available for forests and wetlands, savannahs and wild grasslands, and the greater is the loss of wildlife and the rate of extinction. All farming, however kind and careful, involves a radical simplification of natural ecosystems.

A field of wheat
A new understanding of soil could be the answer to safer, more productive growth of cereals, roots, fruit and vegetables. Photograph: Dan Brownsword/Getty Images/Image Source

Environmental campaigners rail against urban sprawl: the profligate use of land for housing and infrastructure. But agricultural sprawl – using large amounts of land to produce small amounts of food – has transformed much greater areas. While 1% of the world’s land is used for buildings and infrastructure, crops occupy 12% and grazing, the most extensive kind of farming, uses 28%. Only 15% of land, by contrast, is protected for nature. Yet the meat and milk from animals that rely solely on grazing provide just 1% of the world’s protein.

One paper looked at what would happen if everyone in the US followed the advice of celebrity chefs and switched from grain-fed to pasture-fed beef. It found that, because they grow more slowly on grass, the number of cattle would have to rise by 30%, while the land area used to feed them would rise by 270%. Even if the US felled all its forests, drained its wetlands, watered its deserts and annulled its national parks, it would still need to import most of its beef.

Already, much of the beef the US buys comes from Brazil, which in 2018 became the world’s largest exporter. This meat is often promoted as “pasture-fed”. Many of the pastures were created by illegally clearing the rainforest. Worldwide, meat production could destroy 3m sq km of highly biodiverse places in 35 years. That’s almost the size of India.

Only when livestock are extremely sparse is animal farming compatible with rich, functional ecosystems. For example, the Knepp Wildland project in West Sussex, where small herds of cattle and pigs roam freely across a large estate, is often cited as a way to reconcile meat and wildlife. But while it’s an excellent example of rewilding, it’s a terrible example of food production.

If this system were to be rolled out across 10% of the UK’s farmland and if, as its champions propose, we obtained our meat this way, it would furnish each person here with 420 grams of meat a year, enough for around three meals. We could eat a prime steak roughly once every three years. If all the farmland in the UK were to be managed this way, it would provide us with 75kcal a day (one 30th of our requirement) in meat, and nothing else.

Of course, this is not how it would be distributed. The very rich would eat meat every week, other people not at all. Those who say we should buy only meat like this, who often use the slogan “less and better”, present an exclusive product as if it were available to everyone.

Campaigners, chefs and food writers rail against intensive farming and the harm it does to us and the world. But the problem is not the adjective: it’s the noun. The destruction of Earth systems is caused not by intensive farming or extensive farming, but a disastrous combination of the two.


So what can we do? Part of the answer is to take as much food production out of farming as we can. As luck would have it, the enabling technology has arrived just as we need it. Precision fermentation, producing protein and fat in breweries from soil bacteria, fed on water, hydrogen, CO2 and minerals, has the potential to replace all livestock farming, all soya farming and plenty of vegetable oil production, while massively reducing land use and other environmental impacts.

But this remarkable good fortune is threatened by intellectual property rights: it could easily be captured by the same corporations that now monopolise the global grain and meat trade. We should fiercely resist this: patents should be weak and anti-trust laws strong. Ideally, this farm-free food should be open source.

Then we could relocalise production: the new fermentation technologies could be used by local businesses to serve local markets. As some of the world’s poorest nations are rich in sunlight, they could make good use of a technology that relies on green hydrogen. Microbial production horrifies some of those who demand food sovereignty and food justice. But it could deliver both more effectively than farming does.

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Such technologies grant us, for the first time since the Neolithic period, the opportunity to transform not only our food system but our entire relationship with the living world. Vast tracts of land can be released from both intensive and extensive farming. The age of extinction could be replaced by an age of regenesis.

A British farmer’s revolutionary model of horticulture looks like magic, but is the result of years of meticulous experiments

Of course, we would still need to produce cereals, roots, fruit and vegetables. So how do we do it safely and productively? The answer might lie in our new understanding of the soil.

On a farm in south Oxfordshire, techniques developed by a vegetable grower called Iain Tolhurst – Tolly – seem to have anticipated recent discoveries by soil scientists.

Tolly is a big, tough-looking man in his late 60s, with etched and weathered skin, a broad, heavy jaw, long blond hair, one gold earring, hands grained with earth and oil. He started farming without training or instruction, without land or any means to buy it. After a string of misadventures, he managed to lease seven hectares (17.3 acres) of very poor land at a reduced rent, 34 years ago.

“No conventional grower would even look at this ground,” he told me. “It’s 40% stone. They’d call it building rubble. It isn’t even classed as arable: an agronomist would say it’s only good for grass or trees. But over the past 12 months, we harvested 120 tonnes of vegetables and fruit.”

Astonishingly, for these 34 years Tolly has been farming this rubble without pesticides, herbicides, mineral treatments, animal manure or any other kind of fertiliser. He has pioneered a way of growing that he calls “stockfree organic”. This means he uses no livestock or livestock products at any point in the farming cycle, yet he also uses no artificial inputs.

Until he proved the model, this was thought to be a formula for sucking the fertility out of the land. Vegetables in particular are considered hungry crops, which require plenty of extra nutrients to grow. Yet Tolly, while adding none, has raised his yields until they’ve hit the lower bound of what intensive growers achieve with artificial fertilisers on good land: a feat widely considered impossible. Remarkably, the fertility of his soil has climbed steadily.

A tractor moving across a dry and dusty piece of land on a farm in South Africa
New fermentation technologies could enable the release of vast tracts of land from farming. Photograph: Malan Louw/Alamy

On my first visit, one June, I was struck by the great range and health of Tolly’s crops. One plot was a blue haze of onion plants, another a patchwork of sea greens: young cauliflower plants, several kinds of cabbage and kale. There were rows of rainbow chard with gold, green, white and crimson stems. Broad bean pods had begun to sprout from tight pillars of flower. His potatoes were in full bloom, nightshade sinister, stamens like yellow stings. Courgettes extruded rudely behind their trumpet flowers. There were carrots, tomatoes, peppers, beans of all kinds, herbs, parsnips, celeriac, cucumbers, lettuces. He raises 100 varieties of vegetables, which he sells in his farm shop and to subscribers to his veg box.

Separating the plots were untended banks, in which scientists studying his farm have found 75 species of wildflowers. These banks are an essential component of his system, harbouring the insect predators that control crop pests. Though he uses no pesticides, none of the vegetable plants I saw showed signs of significant insect damage: the leaves were dark and wide, with scarcely a hole or a spot.

Almost single-handedly, through trial and error, Tolly has developed a new and revolutionary model of horticulture. At first it looks like magic. In reality, it’s the result of many years of meticulous experiments.

Two of his innovations appear to be crucial. The first, as he puts it, is to “make the system watertight”: preventing rain from washing through the soil, taking the nutrients with it. What this means is ensuring the land is almost never left bare. Beneath his vegetables grows an understorey of “green manure”, plants that cover the soil. Under the leaves of his pumpkins, I could see thousands of tiny seedlings: the “weeds” he had deliberately sown. When the crops are harvested, the green manure fills the gap and soon becomes a thicket of colour: blue chicory flowers, crimson clover, yellow melilot and trefoil, mauve Phacelia, pink sainfoin.

“There’s green manure under the green manure,” Tolly told me. “As soon as we cut the bigger plants, it comes into flower, and the bees go crazy.”

A field of purple phacelia flowers, with cornfields in the backgrounf
Purple Phacelia flowers provide perfect ‘green manure’, ensuring land is never left bare. Photograph: David Collins/Alamy

Some of the plants in his mix put down deep roots that draw nutrients from the subsoil. Every so often, Tolly runs a mower over them, chopping them into a coarse straw. Earthworms pull this down and incorporate it into the ground. “The idea is to let the plants put back at least as much carbon and minerals as we take out.”

Tolly tells me that “the green manure ties up nutrients, fixes nitrogen, adds carbon and enhances the diversity of the soil. The more plant species you sow, the more bacteria and fungi you encourage. Every plant has its own associations. Roots are the glue that holds and builds the soil biology.”

The other crucial innovation is to scatter over the green manure an average of one millimetre a year of chipped and composted wood, produced from his own trees or delivered by a local tree surgeon. This tiny amendment appears to make a massive difference. In the five years after he started adding woodchip, his yields roughly doubled. As Tolly explains: “It isn’t fertiliser; it’s an inoculant that stimulates microbes. The carbon in the wood encourages the bacteria and fungi that bring the soil back to life.” Tolly believes he’s adding enough carbon to help the microbes build the soil, but not so much that they lock up nitrogen, which is what happens if you give them more than they need.

A human tongue with each colour representing a different type of microbe.

What Tolly appears to be doing is strengthening and diversifying the relationships in the rhizosphere – the plant’s external gut. By keeping roots in the soil, raising the number of plant species and adding just the right amount of carbon, he seems to have encouraged bacteria to build their catacombs in his stony ground, improving the soil’s structure and helping his plants to grow.

Tolly’s success forces us to consider what fertility means. It’s not just about the amount of nutrients the soil contains. It’s also a function of whether they’re available to plants at the right moments, and safely immobilised when plants don’t need them. In a healthy soil, crops can regulate their relationships with bacteria in the rhizosphere, ensuring that nutrients are unlocked only when they’re required. In other words, fertility is a property of a functioning ecosystem. Farm science has devoted plenty of attention to soil chemistry. But the more we understand, the more important the biology appears to be.

Can Tolly’s system be replicated? So far the results are inconclusive. But if we can discover how to mediate and enhance the relationship between crop plants and bacteria and fungi in a wide range of soils and climates, it should be possible to raise yields while reducing inputs. Our growing understanding of soil ecology could catalyse a greener revolution.

I believe we could combine this approach with another suite of innovations, by a non-profit organisation in Salina, Kansas, called the Land Institute. It’s seeking to develop perennial grain crops to replace the annual plants from which we obtain the great majority of our food. Annuals are plants that die after a single growing season. Perennials survive from one year to the next.

Large areas dominated by annuals are rare in nature. They tend to colonise ground in the wake of catastrophe: a fire, flood, landslide or volcanic eruption that exposes bare rock or soil. In cultivating annuals, we must keep the land in a catastrophic state. If we grew perennial grain crops, we would be less reliant on smashing living systems apart to produce our food.

A field of perennial rice
While annual rice farming can cause devastating erosion, the long roots of perennial varieties bind and protect the soil. Photograph: Tim Crews/The Land Institute

For 40 years, the Land Institute has been scouring the world for perennial species that could replace the annuals we grow. Already, working with Fengyi Hu and his team at Yunnan University in China, it has developed a perennial rice with yields that match, and in some cases exceed, those of modern annual breeds. Farmers are queueing up for seed. While annual rice farming can cause devastating erosion, the long roots of the perennial varieties bind and protect the soil. Some perennial rice crops have now been harvested six times without replanting.

Perennials are their own green manures. The longer they grow, the stronger their relationships with microbes that fix nitrogen from the air and release other minerals. One estimate suggests that perennial systems hold five times as much of the water that falls on the ground as annual crops do.

The Land Institute is developing promising lines of perennial wheat, oil crops and other grains. The deep roots and tough structures of perennial plants could help them to withstand climate chaos. The perennial sunflowers the institute is breeding have sailed through two severe droughts, one of which entirely destroyed the annual sunflowers grown alongside them.

While no solution is a panacea, I believe that some of the components of a new global food system – one that is more resilient, more distributed, more diverse and more sustainable – are falling into place. If it happens, it will be built on our new knowledge of the most neglected of major ecosystems: the soil. It could resolve the greatest of all dilemmas: how to feed ourselves without destroying the living systems on which we depend. The future is underground.

 George Monbiot will discuss Regenesis at a Guardian Live event in London on Monday 30 May. Book tickets to join the event in person, or via the livestream here.

Regenesis: Feeding the World Without Devouring the Planet by George Monbiot is published by Penguin Books at £20 on 26 May. To support the Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.

The Ecology of the UK’s Snakes

David Beeson, April 2022

A 9-month-old adder in the New Forest. It does not eat until it is over 18-months-old. Size: about a pencil length and width.

I’ve always been a fan of the underdog. If some creature is being ‘got at’ then I’m prepared to put in some effort to attempt to right-the-wrong. That was how it was when I started working with the Mammal Society and then the Otter Trust to stop the hunting of the animal with dogs, the use of traps by waterkeepers and to reverse the trend to extinction that was happening in the 1970s. Human aggression, water pollution and a total disregard of the environment was where I started. And it worked! I set up a nationwide Otter Conference in 1976 and that helped push the survival of the otter in the correct direction.

Male adder, basking in the New Forest gloom. We saw a similar male out and about the same day.
Female sand (green) lizard in the New Forest – suitable food for the adder. Snakes lack eyelids, but lizards have them.

Now, snakes need some support. Their numbers are declining, and their habitat often so divided that genetic flow is impossible, and inbreeding depression a possibility. I did watch adders a few years back and have carried out some very basic research, and the creatures are unaggressive when left alone. Only considerable human or dog aggression causes them to respond negatively. So, if you go out looking for and at snakes you can proceed without fear of being bitten.

The UK has three snake species: the Adder (Viper), Grass Snake and Smooth Snake. All are said to be declining and the smooth snake is already rare. The frequent heathland fires are a negative influence too.

The snakes have their own niches, which largely fail to overlap. The smooth snake are heathland specialists, grass snakes are wetland creatures and the adder a grassland and wood pasture animal over much of its range. Yes, that is an simplification and I have seen adders on heathland at Pullborough Brooks and a grass snake in my, edge of woodland, grassy garden … but it is a fair reflection.  

Why the decline? Well, many reasons.

Firstly, people seem to dislike them. A colleague at work played golf and happily said he killed any snakes he saw with a golf club. No reason really. He was not threatened or, worse, attacked. Just fancied killing them.

Two, their habitat has been lost to farming, golf courses or housing / industry.

Three, dogs, whose numbers seem to increase exponentially, disturb the animals and inhibit hunting and mating.

Four, men with guns. A friend was filming adders for the BBC and all the animals he captured had shotgun pellets embedded in them. The lead shot would, of course, kill them immediately or poison them over a short time.

Five, pheasants (Asian birds) and chickens eat young reptiles and soon eliminate them. The Netherlands bans pheasants to preserve their reptiles. If the UK stopped pheasant rearing the snakes would fair much better. An RSPB reserve in west Wales had a healthy snake population until a pheasant shoot started – the snakes are now all gone.

A male and female adder. My mini-research was to photograph the heads of adders (all slightly different) to start a database.

The Adder or Viper.

Vipera berus, the adder is one of our three native snake species. It is most often seen on heaths and grassy coastal areas. Undisturbed grassy areas are great locations. However, its secretive nature and camouflaged markings mean it often goes unnoticed. Whilst it has a large range across the UK, recent declines, especially in central England, mean it is of major conservation concern. The adder is the UK’s only venomous snake. Though potentially serious, adder bites to humans or dogs are very rarely fatal. There are only around ten recorded cases of death from adder bite in the last 100 years, and most bites occur when the snake has been disturbed or deliberately antagonised.’ ARC.

The animal is found across England, Wales and Scotland but you will need to work hard to find them in many locations. In my own area, north-west Hampshire they have been hugely impacted by pheasant breeding. Even gamekeepers tell me that their snakes have vanished. I would struggle to find one within 20 miles, although I know of many locations where they have been previously. However, Martin Down NNR is a good location.

The distinct black and white colour of the typical male can be much darker – the black adder. The females are usually slightly larger and have an olive / brown / copper complexion.

Female adder in the New Forest.

Adders are not easy to see in the wild as they merge well with their background, are often coiled to conserve warmth and seldom are seen moving. The animals coil and uncoil, round their body or flatten it depending on the weather conditions. I have read reports of their climbing bushes to gain the early or late sunlight, yet I have never witnessed that.

I have seen adders as early as February 14th in the New Forest, and some reports indicate they can be active all winter in mild locations.

Dance

I associate male adders in combat / dancing at the same time as the early purple orchids are in flower – April or May. Why? Well, I was lying down photographing said orchid when an adder pair started their combat dance alongside me! I have lived to tell the tale.  

The dance is a combat of strength with the animals loosely intertwined and moving. They are then oblivious of all around them. The winner will hold that key territory and will mate with the local female.

Female adders breed annually in warm locations and less frequently in colder areas. Their eggs are incubated internally, and you are seen from late summer. The babies are worm-like and vulnerable to avian predation.

Lifespan is said to be up to ten years.

My filming friend was lying down in his home adder pit when a female evaded his cycle clips – employed to stop access to his trousers. The female spent several hours basking on his bum but inside his trousers!

Prey animals are poisoned by injection and then followed until they are immobile and then swallowed whole. Mice, voles and lizards are suitable foods. Hunting may occur at night.

The venom of young adders is stronger than that of adults.

Where to look? Undisturbed grassland fringes and especially grassy areas near heathland. Purbeck is an excellent location.

When to look? When you can see a shadow there will be active snakes. However, they are best viewed early April or May and in the early morning.

How to look? Walk very slowly. They will not hear quiet conversation yet will feel footfall if it is heavy.

Snakes, including adders, are important parts of the ecosystem. Unless actively disturbed they avoid humans and dogs.

Grass snakes have a yellow collar just behind the head. They have no eyelids and are ‘cold blooded’ – that is their temperature is not internally controlled. So, it can be above or below the surrounding temperature.

The Grass Snake, Natrix helvetica

The UK’s longest snake at nearly a metre.  

Grass snakes are found throughout England and Wales and are most likely seen in wet locations. Around Andover the River Test is a good location and especially the Longstock Water Gardens (John Lewis). There are also reports of these animals from Stoke and along the A303. The Salisbury Water Meadows was a good site and I have spotted them swimming in the River Avon.  

Feeding primarily on fish and amphibians, grass snakes can occasionally venture into garden ponds in the summer months, particularly in rural or semi-rural parts of the south. They are not to be feared.

Grass snakes are non-venomous and are extremely timid, moving off quickly when disturbed. If cornered they can feign death, and if handled frequently, produce a foul-smelling excretion. This excretion happened to me as I saved a large animal from my polecat’s attention. My hand and clothes stank for a week, but I soon released the grass snake unharmed.

Female grass snake with a clutch of leathery eggs.

Grass snakes are Britain’s only egg-laying snake. Females lay eggs in June or July, normally in rotting vegetation (including garden compost heaps) which acts as an incubator. The eggs hatch into miniature versions of the adults in the late summer months.

All snakes are protected by law. Observe them and leave them alone.

Smooth snake

The Smooth Snake, Coronella austriaca

I have not seen one actively in the wild. It is a rare animal and a heathland specialist. They also are infrequent baskers, so attempting to spot one is an unrewarding task!

Smooth snakes usually emerge from hibernation in April-early May. They are non-venomous and feed mainly on common lizards, slow-worms and small mammals (especially shrews and nestling rodents), which are captured and constricted in the coils of its body. Live young, which look very similar to the adults, are born in September. Smooth snakes are long-lived and females tend not to breed every year. The smooth snake is a secretive animal and when it basks in the sun it does so entwined amongst the stems of heather plants, where it is superbly camouflaged.

As with all UK snakes, the best location to view them is at The Reptile Centre in the New Forest. There you should see all the types in their large outdoor enclosures.

Resources:

https://www.arc-trust.org/pages/category/snakes

http://www.nwhwildlife.org

Newts on Patrol

David Beeson, April 2022

Palmate newt

We have Palmate Newts, Lissotriton helveticus, in and around our pond. These are amphibians and are rather like lizards in appearance, but with moist, unscally skins. They are often missed by gardeners as they keep a low profile, especially in weedy ponds.

They are not organisms I associate with rivers, although their distant cousins, frogs, will spawn in the shallow and current-free areas. But it could be I’m just not seeing them. You may know otherwise.

Newts are not active in the colder months, and I first see them when our frog tadpoles first appear – in mid-March. And the newts then hoover-up tadpoles at a rapid rate, and I currently can see zero tadpoles despite having around 30-spawn masses in February. Happy and well-fed newts, I think.

Newt pond

Our newts are Palmates, and that is not what one might suspect as they are said to prefer acidic, fish-free ponds.

“Telling smooth newts apart from palmate newts can be trying. Both are brown in colour, with a yellow/orange underbelly, and both species rarely exceed 10cm. The best way to tell females apart is the fact that the throat of the smooth newt is spotted and that of the palmate newt is plain pink or yellow. The male, in breeding condition, is easy to tell apart from the smooth newt. Palmate newt males have a filament at the tip of the tail and black webbing on the back feet, neither of which are present in smooth newts.” Amphibian and Reptile Conservation website.

Our newts have the black webbing, yet the water is distinctly alkaline as the pond is ‘topped up’ with calcium-rich tap water in spring and summer, although overwinter the rainwater will make the water mildly acidic. However, the original newts were transported here from elsewhere, which could have had naturally acidic water. Regardless, they have survived with us for over thirty years.

In the pond, they move around in groups, often a female with two accompanying males. Often the males advance and tail waft hormones (pheromones) to stimulate the female to mate. The females annually lay over 150 eggs, each individually wrapped in water plants. These eggs are 1.3–1.8 mm in diameter (2.2–3 mm with capsule). Surviving eggs hatch to form (my expression) minute newtlets with feathery external gills. There can be a surprisingly large number of newtlets if you investigate a weedy area with a fine net. The external gills are lost before the young emerge onto land and then they breathe through their moist skin and roof of the mouth.

Some publications suggest Palmate Newts are nocturnal – not here! They are very active even in bright sunlight. The species competes badly when fish are present.

You should spot the adult newts all summer, yet they move onto land in late summer and can occasionally be found in damp situations. Over winter they hibernate.

Smooth and Great Crested Newts are also found in the UK.

Our meadows are a mass of cowslips
But there is a genetic flow from garden primulas … hence this coloured cowslip
Bluebells and cowslips in the garden

Website revamp is on its way! Easier searching for articles soon.

The Wild Orchids of Crete in Early April

David Beeson, April 2022

Crete.

Spring in the mid-uplands of Crete is the main time for seeing the flowers on wild orchids. The mild winters, hot summers with winds often coming from the Sahara and the calcareous soils all add to making this a favourable environment. This last winter the rain and snow exceeded expectations, so has encouraged vegetative growth.

Orchis italica is widely dispersed (with the green Smyrnium rotundifolium). On a raised bank, so not easily nibbled or trodden.

You will look in vain for woodland orchids in most places, as there is little woodland, so it is in the open maquis (called phrygana in Crete) that one explores. The three genera you would probably spot are Orchis, Ophrys and Serapias. All these are also found in the UK, but Serapias is an occasional migrant especially to the south-west.

A selection of Spili orchids. The yellow is Orchis pauciflora.

Orchids are short-lived perennial plants that generally grow from a pair of tubers. Here, at Forest Edge, few survive more than a couple of years in a flowering state.

They are monocotyledonous, with parallel veins on their strap-like leaves, a cluster of flowers on the  flower stalk, have colourful bracts and a package of six tepals (petal-like sepals and petals) and their pollen is produced in pollinia. Because their flowers are so different the group attracts more attention than perhaps they deserve, however they can be extraordinarily attractive, and their looking like wild insects to encourage copulation and hence pollen dispersal is an added human attraction. The Ophrys genera’s flowers appear insect-like and are still evolving, so crosses are common and that also generates interest. One is never quite sure what any plant’s flowers will look like – they change colours and patterns. I have a Military x Monkey orchid cross in my garden that is about to flower.

The problems in Crete for the orchids, and flora in general, are the sheep and goat herds plus the ploughing up of orchid-rich areas. Perhaps understandably, the struggling locals gain nothing from their wild orchids and care little. Ditto the authorities, although we have travelled to Crete twice because of them – and that is good income. I have heard it said that the plains above Spili have some conservation protection, yet it is not obvious.

I am seldom convinced by orchid names. They are very variable and folks add titles with little evidence. I suggest this is Ophrys tenthredinifera.

Where and when to visit?

April and early May are the best time. Location – the ‘orchid superhighway’ is on the road between Spili and the Amari Valley. However, you will find orchids elsewhere when animal flocks are not present. Try the Minoan site near Armeni or near Moni Arkadiou.  In the east Plakia and the wonderful Katharo (above Kritsa) have proven good sites.

An orchid site

Botanists from far and wide are attracted to the Spili area and human trampling is an issue. The area needs wardening. It will not happen! We encountered numerous goat and sheep flocks crisscrossing the area, trampled plants and orchid sites ploughed.

Just coming into flower: Aceras anthropophorum, the Man Orchid. This was not in flower on our first visit to the site, but was slightly open three days later. However, it was cold, very windy and dull – so the image is not as good as I would have wished.
Orchis tenthredinifera
Ophrys cretica variant or O. ariadnae
Orchis lactea
Ophrys bombyliflora, Bumblebee Orchid.
Wild iris on the orchid site.
Orchis italica at the Minoan site
Orchis pauciflora
Orchis boryi seemed to prefer moister locations.
Seraoias orchids look unlike many other types. This was photographed near Plakias.
Anemone hortensis near Spili
Anemone coronaria near Spili.
The very last of the Narcissus tazetta were holding on. Found in damp areas near the orchids.

As I said above, ophrys orchids can be very variable and happily cross with other species, so putting an absolute name to any given plant is problematic. Our local guide said we had also seen Ophrys herae and kedra, but my photographs are not clear enough to decide. Barlinia robertiana and Ophrys apifera were at the Minoan site and not photographed this time.

For Annette and myself, being in wild places with the sights and sounds of wildlife is a pleasure in itself. Putting names to plants is okay, but not majorly important to us. The ecology is important, yet deciding why that orchid thrives there and not just over there is quite beyond me!

And, yes, my camera needs changing. Not the best images.

North coast beach with the White Mountains in the distance.
Monastry church at Moni Arkadiou
Overlooking Souda Bay from Aptera.
Roman amphitheatre at Aptera.

http://www.nwhwildlife.org is the homepage. Go there for over 150 ad-free articles on wildlife.

The Coastal Communities of Crete

David Beeson, April 2022

Sand daffodil
Sand daffodil leaves at Plakias

Earlier this month we embarked on a botanical visit to the Greek island of Crete. We have been there twice, previously both walking and seeking plants, but this time headed for the centre of the island, to Rethymno. We had not been to this part of Crete.

Crete is a mountainous island and, despite sitting in the Mediterranean it has snow-covered mountains in April. The highest peak is 2456m, over 8000ft. The bulk of the population is on the north coast and much of the rest is rocky, sheep and goat infested infertile scrub. However, in a very few locations there are amazing numbers and diversity of orchids – and they will be covered in another article.

Roman amphitheatre at Aptera with the White Mountains behind.

Sandy beaches are found along the north coast and that has attracted tourism, yet it also attracts logger-head turtles that come ashore to dig their egg pits. In fact, our own hotel proudly displayed its credentials in looking after its turtles. These endangered creatures come from May until the autumn, so visit then to have any chance of seeing egg-laying.

Many of the beaches are of fine sand with clear seas on one side and towering cliffs on the other. Elsewhere loose agriculture abuts the shore and here we discovered some of the sand-dwelling plants native to Crete.

Sandy beaches are demanding habitats. The plants can be sprayed with salty water one day, pounded by rainwater the next, while between they dwell in shifting sands and 40 Celsius temperatures. But, of course, evolution has driven plants to adapt to these conditions and diverse communities have arisen when allowed.

Plakias, on the south coast, with Ammophilla dunes.

The sand stabilizer is often marram grass, Ammophila arenaria, and this does occur, yet we found it in a limited number of places. The plant has deep roots that can reach non-salty underground water. Its lateral roots stop the sand from drifting too much so other less deep-rooted plants can establish. Among them, and often standing alone and dominant, is the excruciatingly beautiful Pancratium maritium, the sand daffodil. This is a plant we grow, potted, at home. It has thick, flat ribbon-shaped leaves, 2 to 4 cm wide, often showing one or more twists in the blade. It flowers from August to late October with large, fragrant, very showy white flowers. The plant inspired ancient wall paintings. We found it on both the north coast and at Plakias in the south.

The sea holly, Eryngium maritium, was found near Georgioupoli. This has glaucous leaves and blue flowers. Its roots were prescribed as a cure for flatulence.

Matthiola, three-horned stock, is found near the sea, on sand or rocky promontories. The common name refers to the husk of the fruit which has three horns at the apex.

Further from the sea the plant diversity increased with the environmental conditions being less extreme as salt concentrations are lower. There were many annuals here, often low growing. Silene colorata has beautiful showy deep pink flowers with lobed petals and covered large areas. Equally stunning was Matthiola tricuspidate, a greyish-downy annual with four petals in a light pink to violet colour. Sea lavender occurred occasionally, and convolvulus spread around the shrubbier plants.

Both red and blue versions of the pimpernel are found.
Paronychia macrosepala with its small white flowers grouped in flowerheads and surrounded by silvery bracts.
As the shoreline plants gave way to semi-agricultural soils we found squirting cucumber. Ecballium elaterium. It disperses its seeds when its fruit is given the slightest touch – working as a little bomb it bursts throwing its seeds far away. The plant is poisonous.
Sea holly – not Greek photo.

Crete is an interesting island, and worth visiting. We found the pre-Easter weather a good temperature but it is windy and not an ideal spot for a beach holiday. The outdoor pool was 19C. Cold! Walking off roads can also be an issue as they are not maintained and hardly signed; best to go with a walking holiday company.

Olive groves are usually ploughed but the resulting vegetation is used for sheep grazing. We found the groves in the far east of the island more productive for orchids as they seemed less grazed.
Rosey leek in an olive grove.

The spring flowers were exuberant with daisy-like flowers in wonderful numbers around cultivated plots. The big snag being the sheep and goats, that range widely sometimes with human support, eating out the vegetation.

Archaeological sites are good for flowers – the sheep and goats are kept out.
Shepherd and his flock near Spilli. The soils and vegetation are degraded by these flocks and many parts of the island have no significant trees or non-aggressive plants.

Algal Microscopy

David Beeson, April 2022

A bit of a specialist topic, I agree, but stay with me and perhaps I will change your mind about algae … they can be quite interesting. And, as for a microscope, well, mine cost only £105 and it is first-year university standard, but cheap as an unwanted present bought from eBay. Go on, have a look!

The diversity of life is not straightforward. It would be great if everything followed the rules, yet evolution sometimes twitches off the straight and narrow. And, that makes things interesting. Sure, we have animals – things that move and eat other organisms. Then we have plants – green, photosynthetic … mostly. Fungi are hyphoid, non-green and eat other organisms, be they dead or alive. Bacteria lack a nucleus and are microscopic. Then there are all the leftovers that fail to fit neatly into that package. The famous amoeba, that is unicellular and crawls over the bed of aquatic systems is probably best characterised as an animal-like protist, but what about Eugena which can be green in the light, and photosynthesise, yet loses it green and eats other organisms in the dark?  Imagine a pet green houseplant that turns carnivore overnight and eats you up! A triffid?

Algae are often placed in this kingdom

Some biologists place eugenoids within the Kingdom Protista, others are content to label them a plant.

So, let me take you down to the pond and search out Eugena and Chara.

Pond dipping

A glass jar is dipped into the murkiest green-brown sludge of fresh water and is carried back to the kitchen table, to meet your new microscope. A single drop of water is added to your slide and a coverslip added, attempting to exclude air bubbles. Set up your x10 or x4 objective lens and focus (remembering to adjust the condenser and iris diaphragm for the best image). Students never did, but you should now use the mechanical stage to tour your specimen to find the best spot to further study. Now, if not on x10 objective, move there. Wonders of biology will be displayed before you. Perfectly complete organisms greet you whose way of life is a stark contrast to your own.

Spirogyra – a filamentous alga, here with conjugation tubes forming for sexual reproduction.

It takes a while for the organisms to show themselves. Be patient. Filamentous (string-like) algae often show first – strands of quite distinct cells, with cellulose cell walls and clear nuclei and within them a single nucleolus (where the cell is making ribosomes, the protein-manufacturing machines). The green chloroplasts will also be seen, and their design will vary with the species. Along the chloroplast will be granules where carbohydrate is stored – one product of photosynthesis. (Chains of glucose molecules are stitched together, often to form starch grains. But other, similar chemicals are possible.)

If you feel you’d like to be unkind to the algae you could irrigate the slide with a sugar or salt solution. To do this add a drop of solution just outside the coverslip and draw the chemical under the slip with absorbent paper from the opposite side. The osmotically strong solution will suck water out of the cells and their contents will shrink – clearly showing the cytoplasm that forms much of the contents. If you feel guilty, irrigate again with pond water and all will be repaired.

Rhubarb cells before and after irrigating with a sugar solution. Cytoplasm here is pink.

By now you’ll have spotted the unicellular algae actively moving or flowing across the slide. If lucky there could also be colonial algae like Volvox.

Volvox colonies. Each green spot is a flagellate green alga.

A x40 objective is now needed plus a touch to the fine focus knob. You may also my need to adjust the condenser and iris.

The diatoms are characteristic with silica encrusting their cellulose cell walls. The design of the silica is beautiful and seeing it in detail will test your skills with the microscope. Other single-celled algae should also be there and euglenoids – single-celled motile algae with one or more whip-like flagellum.

Surface structure of diatoms.

You will have come across a flagellum before: the tail on human sperm. Internally they are a bit like muscle, with protein fibres (microtubules) that can be moved with the consumption of energy. And you should be able to see this flagellum moving the creature. With luck it is possible to find different types of euglenoids with up to four flagella.

As euglenoids are mobile they can be difficult to ‘pin down’. But, by adding teased out strands of cottonwool to the slide before adding the drop of pondwater, you can slow them down.

Euglena

Clearly, euglenoids have a flexible cell wall plus a single chloroplast that can be ‘killed off’ by the antibiotic streptomycin, and the bleached individuals survive perfectly well by acting as animals and eating small organisms by engulfing them (phagocytosis). Eugena really is a mixture of plant and animal characteristics.

For the biologists … neither sexual reproduction nor meiosis has been observed … possibly they evolved before such things became common.

The green alga Chara is found in my pond, but is uncommon although spread across the globe. I used it with students to study both nuclei and the movement of cytoplasm (cyclosis) around cell interiors – for it is in constant motion here. Also, the cells are huge, and others have been able to suck out the nucleus and study its impact on the cell. A task beyond my pay grade!

Chara

Chara looks like a true aquatic plant, and may be related to ancestral plants. It has root-like anchors (rhizoids) but they contain no transport tissues.

Wikipedia says: Chara is found in freshwater, particularly in limestone areas throughout the northern temperate zone, where they grow submerged, attached to the muddy bottom. They prefer less oxygenated and hard water and are not found in waters where mosquito larvae are present. They are covered with calcium carbonate deposits and are commonly known as stoneworts. Cyanobacteria have been found growing as epiphytes on the surfaces of Chara, where they may be involved in fixing nitrogen, which is important to plant nutrition.

Chara emits a strong musky odour when crushed.

Nitella and Chara are similar.

You will find videos on these organisms on the Internet.

Stock dove courtship

David Beeson, April 2022

Wood pigeon
Stock dove

Wood pigeons are common here, with our resident pairs that court and mate on our garage roof and nest in our trees and thick hedges. Those birds are joined, overwinter, by flocks of perhaps sixty migratory wood pigeons that roost in our walnuts and graze the meadows. The two types ignore each other and ourselves. We get on fine with them all.

We also have stock doves with their refind body design, beautiful feather hues and a gentle cooing that enlivens our time in the garden. They occur in low numbers, presumably territorial and we have a single pair. Periodically that pair nest in the tawny owl box on one of our old wild cherry trees, otherwise, they possibly take over old squirrel dreys or holes in local trees. Yesterday they surprised us as we witnessed a courtship aerial dance.

Imagine an unequal circle, an ellipse, about 20m by 15m in the air at about 20m high. A pair of stock doves flew this circuit around twenty times between our large walnut trees and the forest oaks and ash trees beyond. They were almost within touching distance of each other, possibly 20cm, with the upper bird just behind and periodically flapping more intensely. They were fixed in position and enjoying a sequenced aerial dance. It appeared exhausting.

I have never seen this courtship before, nor can find a reference to it on the Internet. It is quite different to any wood pigeon behaviour, which can involve males vigorously wing flapping and clapping.

Comments and observations would be especially welcome. Dandabeeson@gmail.com

The Deer of Southern England

David Beeson, March 2022

A male Muntjac decides if I offered a threat. I didn’t and he just quietly wandered away.

UK deer have antlers that are shed yearly, while sheep & goats have horns that grow and are not shed. Although you are unlikely to need that fact in the field!

Deer are Ungulates, having hooves instead of claws and they are in the Cervidae family, being ruminant browsers and so have lost their upper jaw molars. This is an easy indication of the family if you discover a deer’s skull.

The deer you are likely to encounter are: Red Deer, Fallow Deer, Sika Deer, Roe Deer and Muntjac Deer. Chinese Water Deer occur in the east, although a now extinct colony did occur in the 1960s near Basingstoke in Hampshire. Red deer are substantial animals, while the smallest, muntjac, are large Labrador in size. Only red and roe are native.

Male red deer with deer park large antlers.

Red deer are mostly found around Southern Hampshire, Thetford Chase and the far West Country in Southern England. The species, in various forms, is widely distributed in North America (called Elk), Europe and the Far East.

Cervus elaphus is a large red-brownish deer lacking spots at maturity. The hoof-prints (slots) can be 5 – 7cm wide but widen when running. The black, oval droppings are around 3cm x 1.5cm. The males, stags, thrash vegetation when clearing the dying skin and hair (velvet) before the autumn rut (mating).

Antlers are found only in males, and they grow yearly, increasing their size and complexity until an animal reaches old age. The number of points is not an indication of age as growth varies with feeding conditions. Antlers are cast in February or March and soon after start regrowth from bony pedicles on the skull. The growing antlers are covered in blood-rich, hairy skin. You can discover shed antlers, but they are soon gnawed by other animals to consume the minerals. Even antlers I have stored in a shed were partly eaten.

Male red deer, growing antlers and moulting.

Deer moult and winter coats are usually darker and thicker.

It is a deer tolerant of both deciduous woodland (New Forest), coniferous plantations and open moorland (Dartmoor and Exmoor). Males and females associate only during the autumnal mating season when the stages bellow to hold territory. Fights are common between seemingly equal males. Young are birthed in June or July with lactation until the autumn common.

For witnessing the rut in the New Forest, head to the Ornamental Drive to the west of Lyndhurst.

Feeding occurs throughout the day and night, although disturbance makes them more nocturnal. They are browsers but also feed on grasses and heathers. They are ruminants and will ‘chew the cud’ when at rest.

The adults have no natural predators in the UK, so populations need culling if winter and road attrition does not stabilize the population.

Fallow in summer
May 6th, New Forest near Black Knowl. Two herds of fallow deer graze, each were mixed sexes and about 30 in each group. One white female was present in this group and the males retained their antlers.
At the limits of my telephoto lens!

Fallow Deer, Dama dama, have palmate antlers in the males. Coat colour is less spotted and darker in winter and mostly a reddish-fawn. White and black colour variants are not uncommon. They are a beautiful deer and often encountered in parks. Wild populations occur along the South Coast, East Midlands and East Anglia. I have had herds in excess of thirty in my own garden. They are a common species in Central Europe.

Slots and droppings as red deer but smaller in size, as is the animal (up to 70Kg, with Red Deer to 225Kg. for a big eight-year-old male.)  Males’ antlers shed in April or May with the rut later than red deer, in September to October. In the New Forest head to the Deer Sanctuary area west of Lyndhurst. Single fawns are born in early summer. Fallow are herd animals.

Feeding: more likely to graze than other species, with grasses 60% of the bulk. Acorns, chestnut and fruit also eaten. In Harewood I have seen them take wild apples and blackberries.

The original fallow deer are said to come from Turkey-Iran.

Animals can survive for over 20 years in parks, half that in the wild.

Winter coat, full set of antlers, sika deer.

Cervus nippon, the Sika Deer. The name gives away the origin of this introduced species – Japan and southern China.

Fallow Deer in size with small red deer-like antlers in the males. Concentrated around the Southern New Forest (About 200 animals) and South Dorset and westwards (2000). Best places to see sike are: Arne RSPB reserve, Wareham Forest and south of the railway line that bisects the New Forest.

Droppings and slots not easily distinguished from fallow and roe. Weight of a mature animal is up to 65Kg. Especially found on acid soils and amongst coniferous plantations eating heather, grasses and browsing trees. Seldom seen in the open. Herd species.

Rut and life cycle as Fallow Deer. Male vocalise during the rut with high-pitched whistle.

To see the rut, go to RSPB Arne’s field system near the farm buildings in late September.

Roe buck

Capreolus capreolus, the Roe Deer, are modest in size (25Kg) and are found not in herds but family groups. These, again, are attractive animals, well designed to dwell in deciduous woodland and the agricultural fringe. They are easily recognised and, if running away, appear virtually tailless but with a clear white-cream rump patch. Like the other deer they moult from a grey winter coat to a redder, thinner one in summer.

I first encountered wild roe deer vocalisation near Salisbury when one barked nearby … I thought it was some predatory African mammal! I’ve been in love with the mammal ever since.

If the animal is new to you, which is unlikely as the population has increased hugely in my lifetime, you will first encounter it when you feel watched in woodland. Peer around and ten metres away you’ll spot the roe patiently observing you in the dappled shade of an oak tree. After mutual appreciation it will slowly turn and wander off, soon vanishing into the foliage. On the other hand, if the animal feels fear, it will crash off barking to warn the rest of the family.

Field signs: slots 4.5 x 3.5cm. Droppings: 1.4 x .8cm or smaller, as usual with deer in clusters of individual faeces (In summer may stick). We always know when these deer have been in our garden as the rose bushes are left leafless to one metre high. Remembering that most leaves are partially toxic, the deer take a little of this and a little of that … except roses!

Male roe mark their territory by rubbing their antlers up tree stems about one to two centimetres in diameter. The removal of the bark leaves a clear lighter patch at about knee-height to a human. Look for these along the edge of woodland tracks.

Found throughout Southern England and widespread through Europe.

Twins are born in May or June and the rut is in early summer – with the females being chased in circles. (I have only witnessed this once.) Males alone have antlers and they are shed in November and regrown by March. The biggest antlers I have seen (Black Forest in Germany) had 4 points each; three is more usual, but with their ‘pearling’ around the base increasing with age.

Roe

As with other wild mammals, external and internal parasites are frequent. Ticks can be seen even from a distance, with ears being especially attacked.

Antlers. Note ‘pearls’ on the older antler.

Can survive to 18 years, but 8 – 10 more usual. Roads are lethal to the species, with only muntjac appearing more commonly (locally) on the road verges.

A lovely animal, and I especially enjoy watching them wander through Harewood Forest. If you have the courage, go out on a clear night (leaving your torch behind) just at dusk. Your eyes will soon adjust, and it will appear almost like black-and-white daylight. Now the roe will most ignore a non-speaking, slowly wandering human. I have even taken out small group of dads with young children and walked within a few metres of roe. The children often encounter rival males barking to each other from their territories. Magic! Add in the bats and tawney owls and you have the stuff of memories and wildlife enthusiasm for life. (Just do not get lost!)

Male muntjac

Lastly, the Muntjac DeerMuntiacus reevesi. A rapidly expanding species that is moving from dense woodland to being seen everywhere. Given a chance they mightily enjoy my garden. During almost any drive in North Hampshire you will encounter one or more dead muntjacs at the side of the road.

Males have short simple antlers, prominent canine teeth and a retreating animal shows its long white tail sticking upright. Once seen you will not mistake the chunky, small (15Kg) species.

Field signs: Slots 3 x 2cm, droppings: small and especially pointed at one end, in heaps. Dropping sites often reused.

Solitary species with the common name of barking deer, as the females bark when in season for ten or twenty minutes at two or three second intervals. They appear to mate at any time of the year from the distribution of calling females locally.

I encounter females with a single offspring much more frequently than males. One female holds a territory just beyond our fence and she barks regularly and loudly with it carrying hal a kilometre.

When encountered muntjac wander off quietly, unless caught in more open woodland when it is a determined trot with the tail up.

In Harewood Forest we have all these species, except sika. However, the red deer population may have been shot out as I have not seen any for several years.

Any walk in Southern England will allow you to encounter ‘high seats’. These are shooting positions for deer numbers are not controlled naturally and populations are getting too high for the survival of some plant species. For example, locally butterfly orchid seed heads are desirable to deer and the orchid’s distribution is rapidly declining. So, despite my dislike of shooting, I regret that I have to accept deer control. However, I would prefer wolves and lynx to carry out that function.

If you have never experience a deer rut, make this year the time to change that.

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Small Mammal Carnivores of the UK – Martens, polecats, stoats and weasels.

David Beeson, March 2022

This article will look at the pine marten, polecat, stoat and weasel. The former pair are very unequally dispersed, while the latter two are mostly found across the British mainland.

Early 1970s and my lovely wife takes our pet polecat for a wander across the Salisbury watermeadows.

I have only seen one live, wild marten, and that was in France as it hurtled across a road. Many are killed, and so visible, on Crete’s roads as it is their top carnivore and numbers are healthy, but they are beech martens, not the UK species. If you want to see one in the UK, one of the viewing spots in the Highlands is the most reliable location – but it failed for us. Martens do occur in The New Forest, Forest of Dean and Mid-Wales into West Shropshire, however in low numbers. They also occur in Ireland.

However, as martens sit near the top of the food pyramid their numbers will always be low, and their density suggesting seeing one in the wild a poor bet! Better to try a UK wildlife park, although a keen spotter can locate their twisted droppings.

Denning often appears to be in tree cavities, although artificial nest boxes and cottage roofs are popuar.

PIne marten
Polecat

Polecats have spread out from their C20 relic population in West Wales, around the Hafod Estate inland from Aberystwyth. They now occur across the whole of Wales, English Midlands and Hampshire. Other populations do occur. A friend caught one alive in a rabbit trap and road kills are not uncommon around Andover. I had a pet polecat-ferret for many years until he eventually escaped, as have others of his type.

The polecat was also called the foul-mart as, unlike the sweet-mart (martens) they often exhibit a strong territorial marking scent. (Our cute animal was only allowed into the house during his two-month non-aromatic phase!)

A polecat’s droppings are similar to a marten’s with fur visible and the scats thin and usually twisted. They are often left in a prominent location to serve also as markers. Size: about three centimetres long and, when fresh, about 2/3 cm wide.

Our polecat, called Poo (Short for the specific name of  [Mustela] putorius), could swim well and loved being taken for walks on a cat lead / harness. However, once Poo understood the route had turned back towards home he would walk no further and needed carrying.

Poo escaped three times, the last time not returning. On the first occasion he was caught by a gamekeeper and dumped into a cage. When I reclaimed him the keeper asked, “’Ow do I noes he’s yors?” In response I took him out of the cage and put his head to my face – he licked my nose rather than take a chunk out. “He’s yors!” he said.

Poo was unafraid of anything living. Dogs soon kept well away, and a cow ended up with a sore nose when it paid him too much attention.

When running free on our local water meadows, Poo would scare rabbits out of hollow willow trees, on one occasion a rabbit jumping out above head height over me. Also, he caught a grass snake as it was swallowing a toad … both survived the event, although as I released the snake it vented a foul-smelling liquid on me that lingered for days and then played dead.

Poo was a exhibit I took round with me when giving talks or lectures about otters. Otters at that time were unprotected by law, still hunted with dogs and near extinct. Our polecat helped in gaining legal protection for Lutra lutra.

Stoat

The next smallest carnivore is the stoat, and this is found throughout the UK including Northern Ireland. They frequent Harewood Forest adjacent to my home, wander our garden and one killed our pet rabbit. The animal is mostly active during daylight, in contrast to the first two.

The strength of a stoat is amazing. I have watched a female climb over a metre-high wire fence with a dead rabbit many times its own weight. The same animal had found a den of young rabbits and she took them one at a time back to her own young hidden away in a rabbit burrow, each time climbing the fence.

I have seen stoats in ermine (white winter coat) in the USA. They do not change colour in Southern UK.

Weasel

Finally, we have the diminutive weasel. With only a fleeting view distinguishing stoats and weasels is near impossible, especially as there are baby stoats of about the same size. Weasels are often a lighter colour and lack a black tip to the much shorter tail.

Weasels are not found in Ireland but widely distributed elsewhere. I have seen only a handful of wild sightings, often with just the head looking out from a mole or vole hole or dashing across a road.

[Yes, I have ignored the wild cats of the Scottish Highlands as encountering one in the wild, for most of us, is a distant dream. However, the wildlife park on the edge of The New Forest had several pairs. Wild American mink are also found here, yet I have not encountered one for over 40 years.]

The feeding niches for these four species overlap, but in essence UK martens are more likely to feed on squirrels, but spend much time at ground level. The polecats especially feed on rats and rabbits, often feed at night. Stoats prey on rabbits and climb trees for young birds, while the weasels hunt in rank grass and along hedges and walls for voles. In our garden weasels frequent mole tunnels.

Droppings

But, yes, that food separation is a big simplification. Carnivores will attempt to take anything they can overpower, with weasels known to even kill adult rabbits many times their own weight.

Life expectancy is highest with martens (17 years) and least with weasels who seldom live to two years of age. With persecution, life expectancy is often related to game bird breeding and the use of rodent-killing chemicals (Warfarin). I once spent a day out with a ‘tame’ gamekeeper, he shot at anything that moved unless it was a game bird.

Both weasel and stoats can charm. This sometimes occurs in our garden, with the  stoat rushing about, flipping somersaults and behaving very oddly. The watching squirrel was fascinated, came close but vanished when the stoat rushed behind the tree, climbed and then descended in a failed attempt to make a kill. I have also witness stoats effortlessly climbing our trees and then investigating nest boxes for food.

With the demise of the local rabbit population to a viral disease I have seen less stoat sightings.

Poo
Who am I? Notice the ticks in the ear and on the head. This is an issue for small mammals.

In ermine

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The Mole

David Beeson, March 2022

I could have started with a question: Which mammal is often around us, yet we seldom see? Because it is true. I have moles in the garden, they tunnel through the flowerbeds, under the lawn and, this winter, ploughed up chunks of our wildflower meadows, yet I’ve not seen one in years. I watch as they throw up diggings as they re-tunnel, but I do not see their velvet black body, chunky front limbs and small eyes. A female often builds her breeding nest near the house, but she keeps hidden.

The mole, Talpa europaea is present throughout England, Scotland and Wales but absent from the island of Ireland. It spreads through Europe to middle Russia and south to northern Greece, but is not found in much of Spain or Italy – where possibly the ground is too hot or dry for them.

You’ll know if a mole is around by its molehill excavations or by the lifting of turf as it burrows just below the surface. But such features are only temporary, and the molehills are washed back onto the soil surface with time and surface tunnels crushed by animals’ feet or chunky lawnmowers. With soils drying and hardening in the summer, most molehills are generated over the damper, cooler times of the year.

Tunnels do not only occur near the soil surface. Others will be much deeper and can be used to find food when soil invertebrates are driven deep by soil dryness.

The mammal occurs even in wet pasture, where larger molehills occur. Dog owners tell me that here their pets do catch surface moles there, presumably the animals are driven up by the flooding of their tunnels.

To survive on an adequate diet of worms and soil invertebrates our mole will need a permanent set of tunnels that function as traps, so colonising new land is easier from an established territory. Merely releasing a captured animal onto fresh land will kill it, as there will be no tunnel system it can adopt. No extensive tunnels equals no food.

To many a person’s surprise, moles are frequent in woodland with sufficiently deep soil, and are found on sand dunes and moorland but in lower densities. They are solitary with males 150% the weight of females.

European mole

Moles often have three periods of activity during a day each lasting three to four hours, but less if food is abundant. The mammals traverse their tunnel system looking for food that has stumbled into the system. When they dig they are not actively searching for food; they are merely extending their territory.

Breeding occurs in spring with births in late April in Southern England. Litters of 3- 4 are usual. Juveniles disperse within 6 weeks and have to search out their own territory – causing a high mortality.

Killed moles

In my garden, Talpa europaea are hunted by weasels underground, although any dispersing above ground may be taken by many predators. On local cricket grounds they are killed by the groundsmen and dead moles can sometimes be seen tied to fences. Poison is not legal, but tunnel traps are often set. In my early days, I attempted to disperse garden moles with a sonic system and smelly tunnel inserts. It did not work, and I settled down to let them live alongside us.

A three-year-old mole is doing well but some survive to reach six years.

Trapped mole.
Live traps are available that allow moles in but not out. They must be checked at least twice a day.

The design of a mole is probably well known, yet their physiology to survive underground with limited oxygen is interesting. You will know that there are different types of haemoglobin – the oxygen-carrying element of red blood cells. Some can fully absorb oxygen at low concentrations – useful for either living high in the mountains or below ground in poorly ventilated spaces. This is how moles survive in such a hostile oxygen environment. Their bodies also are much more tolerant of high carbon dioxide levels – certainly levels that would kill me.

Moles can be positive in a garden opening up air and drainage channels.

Having caught a few live moles, I’m aware of their strong digging ability and high-pitched squeak when held. Yet, despite needle-sharp canine teeth, I have never been bitten.

We now occasionally complain about our moles, while leaving them to live their lives around us. We quietly ignore each other. Try to do the same.

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I had forgotten just how magical a drop of pond water can be.

David Beeson, March 2022

I’m about to sell my microscope, as a new one is on its way to me. So, I thought I would give the old one an outing – a sample of pond water. Oh, what wonders! If you have access to a microscope and have never looked at pond water do it.

The first thing you’ll spot, once the microscope slide has its drop of water and a coverslip has been added, will be big circular organisms. Clear in the middle with a distinct dark line around the edge. What can it be? Answer: an air bubble, because you, in haste, didn’t lower the slip one side first, but just dumped it down directly. Woops. Then you find the image is unclear, so you start again and clean the eye and objective lenses with lens tissue or optical glasses cloth. Double woops.

Microscope

So, with the substage condenser as high up as it will go, then down half a turn, you adjust the iris diaphragm to be as small as possible (gives more detail, as in a camera) but with enough light reaching the slide.

Always start with the least powerful objective lens and carefully lower it until it is close to the slide and coverslip, and adjust the slide to the best position. Now, at last, you are allowed to look through the eye lens and slowly move the focus to raise the objective lens to focus. Wonderful things become visible, especially after you employed the fine focus. Minute creatures dart across your field of view, others twirl and gyrate. Yet more you spot attached to debris.

Now, using the fine focus move it slightly up and down to spot the three-dimensional aspects of the miracle before your eyes, before moving the slide to seek out the best possible location of the ‘soap opera’ before you.

I spent most of the time using a x10 eye lens and x10 objective – low power, x100 total magnification. High power is x10 x40, or x400 total magnification. But, if you have a x4 objective that can be useful for larger objects such as aquatic leaves. It is possible that your machine has an ‘oil emersion lens’ – don’t use it unless you’ve been trained in microscopy, as you need to use a special oil between the lens and slide and it can get very messy.

Single-celled algae

What did I spot? Lots of single-celled round algae, the base of the food chain. The twirlers are euglenoids, cute algae that think they are animals in that they can both photosynthesize and engulf minute food, all the while hurtling around using a spiral flagellum. Wonderful!

Euglena
Euglena

Then I mounted some weed on a slide and studied it. The individual cells were clear and lots of filamentous algal strands were attached. Here the cell wall and cell contents with its green pigments came clear. Later in the year I can be voyeuristic as algal sex occurs before my very eyes with conjugation tubes and moving cytoplasm beating any human ‘blue movie’. Perhaps!

Filamentous alga. You will spot many types.
algal sex

And, what is that? Ah, vorticella. It’s a stalked single-celled animal (protozoan) with a fringe of minute cilia beating to draw in aquatic bacteria to its gut-like structure.

Vorticella

Now do I go for bigger things? Like, capture a tadpole in a small dish, with minuscule amounts of water, so I can look at its tail and see the blood capillaries and even the red blood cells passing through it? No, I’ll save that for another day.  

Does anyone want to buy my microscope before it goes on eBay?  

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The Home Lives of Fungi

David Beeson, March 2022

The fungi are the organisms that form the Kingdom MYCETEAE, and are neither plants nor animals, and bear very little resemblance to bacteria or algae. So, they are fascinating when you get to know them. And, that is my task today – to enable you to see life from a fungal’s point-of-view.

(Previous articles have elaborated on the generalised structure of a filamentous fungus and of slime moulds, so we can skip that. But, recall that some fungal strands (hyphae) are not divided into cells yet others do have cross walls. They have a true nucleus, mitochondria, ribosomes and other organelles but their nuclear divisions (mitosis and meiosis) are rather odd.)

Myceteae are sub-divided: slime moulds, Ascomycetes, Basidiomycetes and some others I’d prefer to forget! All three types you should find in a damp UK autumn, and some others on some bread or cheese left out far too long (Bread moulds, mucor & penicilliums).

Fungi are never photosynthetic but release digestive enzymes to solubilise their food, just as we do along our gut. There are three lifestyles: parasites that leave the host alive, necrotrophs (necro = death, troph = feeder) feed and kill their host and saprotrophs that attack dead material and decompose it.

How do the fungal enzymes work? Well, plant cell walls contain chains of glucose-like molecules as insoluble cellulose and similar chemicals. Being long chains, they are insoluble and are great for making plant structure. (The last thing a plant wants is for its leaves to dissolve in the first rainstorm.) Fungal enzymes break these chains into their individual units, absorb them and use those materials in their own metabolism. So, dead leaves are broken down and their stored resources recycles, fungi cause rot on fruit and digest the trunks of living trees. And a bit closer to home, some attack us – Athlete’s Foot, Thrush and Ring Worm (yes, it is a fungus and not a worm.) Yeasts are unicellular fungi, and they break down sugars and starches in wine and bread manufacture.

With hundreds of thousands of fungal species there will be one that can attack almost everything. Some fungi live in thermal pools, others in Antarctica and some in your freezer, if not at minus 18 Celsius.

A healthy plant may be able to fight back against infection by killing its own cells or laying down cork near the fungus, so depriving it of most food supplies. Other plants manufacture expensive fungal toxins, but potatoes easily succumb to Potato or Tomato Blight through the stomatal pores of the leaves and soon wave the white flag. Human skin has an anti-fungal immune response, yet warm damp spots may allow the fungus to evade it.

While the vast bulk of the ‘traditional fungus’ is hidden from us, they do need to show themselves to allow their reproductive spores to be dispersed – the fruiting body. The fruiting body is composed only of hyphae, but they can be of three types. 1) Thicker-walled structural hyphae, 2) small, sticky and much branched binding hyphae and 3) hyphae that produce the spores. There are no specialised transport tissues like a plant’s phloem or xylem.

Fungal sex. Start at #1 and follow round clockwise for it to make any sense at all! The main fungus body has nuclei with only one set of chromosomes (Haploid,n)

As far as I know, it requires two different strains (forms) of hyphae to meet and to fuse nuclei in sex before a fruiting body develops. These hyphae grow into the fruiting body and at their tips undergo meiosis (reduction cell division) to for the spores. Released spores can potentially germinate to form a new fungal organism or remain viable but ungerminated for years. Clever!

Spore print

It is traditional to make spore prints in the autumn by laying a basidiomycetes fungus on paper. (The technique does not work with the other types.) The colour of the spores is an important factor in the organism’s identification. (Spraying with hair spray will preserve your print.) Spores may germinate in a dilute sugar solution on a microscope stage.

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The Invasion of Land, and the first land plants … The Bryophytes (Mosses and Liverworts)

David Beeson, 28th February 2022

At water level are the liverworts. The zone above them is moss and a fern joins them. New Forest.

About 450 million years ago, in the Silurian era, plants invaded the land. With water and land / air being such different habitats evolution had to throw up some divergent life forms to survive there. It would take millions of years for the complete colonisation of land. The first true land plants were the bryophytes, including the mosses and liverworts, although the algae were the link.

After the bryophytes had established themselves the sequence was: horsetails, club mosses and ferns, to gymnosperms (conifers) and finally the angiosperms, the flowering plants.

Everyone has encountered osmosis at school. Osmosis is all about gradients, so let me elaborate.

Place a car at the top of a hill, take off the brake and it will naturally run down the elevation GRADIENT. High to low.

Open a strong perfume bottle and the aroma will spread out from high to low along a perfume GRADIENT.

Breathe in some air into your lungs. The oxygen is in higher concentration in the lungs than the blood, so it flows down an oxygen GRADIENT into your blood, while carbon dioxide flows along its GRADIENT out of the blood and into the lungs.

In biology gradients are everywhere and are critically important. If an organism cannot use a gradient it has to employ energy to pump the material, and that costs. Gradients are free.

Osmosis is about water gradients. Less water outside and water flows in along a water gradient.

Imagine some algae in a transitory pool of salty seawater. The alga has many chemicals inside its cells, so has less water than the sea. Water flows in along a gradient – osmosis. The pool dries out in the sunlight, now the water gradient changes, and the alga can lose water by osmosis. Death … unless it has some clever trick.

The trick is to have a waxy, non-cellular outer layer, called the cuticle, that inhibits water movement, and to have a cell membrane that can actively control it. (The cell wall is very permeable to water, indeed water flows through it from one cell to the next and that is an important function.)

In a wet / dry environment evolution forced the survival of algae with thicker, more efficient waxy cuticles … and some rockpool algae still have a cuticle layer.

There were other problems to solve in moving to a terrestrial existence. There is 280 times more carbon dioxide in water than oxygen. That’s good for photosynthesis, which obviously needs it. In the air there are 570 oxygen molecules to every one of carbon dioxide, which also moves more slowly in cells. So, land plants have a problem with carbon dioxide supply. A waxy cuticle only antagonises this problem. The solution appears to be in having a waxy layer on the upper surface and (closable) holes on a plant’s lower surface – stomata.

Eventually, with increasing size plants would need a transport system (Phloem and xylem), supporting mechanisms (woody cells) and roots to seek out and supply water and nutrients. And, of course, some sexual mechanisms that did not need gametes swimming from plant to plant.

The Bryophytes.

Mosses.

We are all familiar, in the UK, with the green mosses that coat trees, fences, roofs and the ground in damp locations. Yet few people understand their structure and life cycle. A life cycle called ALTERNATION OF GENERATIONS … and this is one that occurs in all land plants, including trees. Essentially, plants switch between two forms in their life cycle – gametophyte and sporophyte.

But, first, let us look at a typical moss plant.

Depending on the time of the year you look at one, you should see a stem covered in minute green leaves (the gametophyte)  AND a non-green addition to the top, shown as the sporophyte below.

Polytrichum

This plant has no true roots, no phloem or xylem*, no lignin to make wood, a very limited cuticle and such thin leaves that stomata are not present (but maybe on the sporophyte). Mosses can lose water easily. As such, mosses live almost exclusively in damp conditions and are small plants. Their gametes still need water to complete their sexual reproduction.

*In Polytrichum there are some dead cells in the stem centre that can carry water upwards, yet it is not xylem.

Life cycle diagram.

The photosynthetic plant is the gametophyte, and surprisingly it has only one set of chromosomes. (We have two sets, as do most organisms we meet daily.) As you will have guessed, the gametophyte can produce gametes – male (motile) and female (non-motile). If fertilization occurs the resulting zygote will grow into a sporophyte, which is parasitic on the gametophyte, has two sets of chromosomes and is non-photosynthetic. Eventually, the sporophyte produces and releases spores that can germinate into a new green gametophyte. (For biologists, the spores are produced via meiosis and the gametes by mitosis. Not what you might expect. A great exam question, so watch out!)

The sexual cycle alternates between gametophyte and sporophyte – Alternation of Generations.

Sphagnum is a moss genus, there are many different types of sphagnums. In many ways, they are quite distinct. They dwell in waterlogged situations, under acidic conditions, especially in floating rafts, in raised bogs and they die and fail to decompose in anaerobic, acidic conditions to make Sphagnum peat … that holds a huge carbon store.

(If you ever only have sphagnum and salty water, and need drinking water … by passing the water through the moss it acts as an ion-exchange mechanism, and the salt is held by the moss and the water come out drinkable. Sodium and hydrogen atoms are exchanged.)

The sphagnum gametophyte can hold twenty times its own mass of water, ensuring a very wet bog even if the water table is well below the surface. Also, its structure contains many large, dead cells alternating with photosynthetic cells and that is where the water is stored. Squeezing pushes water from these dead cells but leaves the living cells intact. And sphagnum’s outer shell of leaves can channel water upwards without any need for an internal transport system.

Many sphagnums are coloured, with cells containing the red anthocyanin pigment.

The spore-producing sporophytes are not easily spotted in sphagnums, but keep your eye out for one as you slowly sink into a bog in June or July. You will die happy, perhaps.

Typical Beeson field trip

Liverworts

Most of the liverworts I encounter are flat, green structures seen clinging to a very wet surface such as a bridge’s support at water level. Look also alongside waterfalls or where springs emerge from soil. You may encounter them growing in nursery potted plants.

Liverwort gametophyte

This is the gametophyte, and the structure is quite distinct from the mosses, although some more leafy ones occur clinging to the surface.

The reproductive structures are quite distinctive.

Reproductive structures
Life cycle

Bryophytes are not everyone’s favourite plants but they have their devotees. As a group they probably evolved from green algae about 430 million years ago, so have survived well and have even colonised tall trees in wet environments. Yet, lacking effective water transport and supporting tissues they remain close to their substrate and depend on water in which their male gametes can swim. They are poorly adapted to life on land. The next groups, including the ferns, can survive in drier locations and are bigger.

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