We have endured heavy winds and rain here in the Scottish Borders for a few days. All is calm tonight, with a bright moon lighting up the fells around us. The Forestry gamekeeper will be out looking for deer to kill tonight, before midnight. I hope he does not see them.

Today the sun shone with winter fierceness, low in the blue clear sky. I used the opportunity to take photos of the beautiful lichens and mosses which grow everywhere here, on rocks and trees. Our dry stane walls are crammed with lichens and mosses which have taken hold since they were built, back in the mid 1800s.

I have spent many hours researching these wonderful life forms and now have a better understanding of the differences and purposes they contribute to the environment.

It seems best to start with Fungi as they have inhabited our planet for millions of years and have survived the two great extinctions. They are a constant in our world. Fungi are life giving and life taking. We would not exist without them; yet they can kill us.

Fungi began as simple organisms existing in lake and river water then worked with plants also in the water to interweave their fine threads around their roots. That relationship encouraged the plants to grow in the land using ‘fungus roots’ or ‘mycorrhiza’.

What we see above the ground, such as toadstools and mushrooms is only a tiny part of what lies below ground. Mushrooms and the like are the spore bearing bodies produced by the mycellum which is the hidden parts of fungi below ground. The mycellum is a mass of filaments which are known as hyphae and their bunching together is called the mycellum. The spores are the result of the reproductive process which fungi are constantly working toward.

Fungi work imaginatively. A single mushroom sheds millions of spores, which are usually dispersed by wind, rain or contact with insects and other animals. The ‘Stinkhorn’ mushroom, emits a smell of rotting flesh. Attracted by the smell, carrion flies and beetles visit it and the spores are embedded in mucus which sticks to the visitors’ feet. Spores are then deposited wherever the insect lands and so are widely dispersed. In Brazil, there is a fungus which can infect ants such that their filaments extend out of the ants brains. Only when they have controlled that brain and directed the insect to a suitable location for fungi to grow do they kill their mobile carrier and develop their own progeny on the chosen location.

Fungi can take many forms above ground such as coral-like shapes, puffballs, brackets, cups, flat sheets of tissue or gelatinous blobs. They may also be a single-celled yeast fungi, so tiny these are known as ‘micro-fungi’. All forms are the resultant reproductive manifestation.

Anyone who want to make their own fungi (yeast) for making bread could try this (which I took from a bread making forum)

Ingredients

3 Store starter in a wide mouth glass jar. I use waxed paper and a rubber band in place of a lid, as metal utensils or containers will contaminate the starter. Once refrigerated, the starter only needs to be fed once a week. Use half, and feed the remaining half to keep it alive for the next time

This describes the need for fungi to be kept alive in order to multiply.

Outside, wherever I look, I now know fungi are busy.

Fungi fulfill an important role breaking down dead material. Also, as they cannot photosynthesise, they scavenge instead, absorbing mineral salts and other
nutrients such as organic phosphate from the surrounding soil, which they in turn make available to their host plant. Fungi can also protect host plant roots from grazing by invertebrates. In exchange the fungi receive sugars, carbohydrates and vitamins created by their host plants during photosynthesis.

Fungi provide food and shelter for many insects and other creatures. One creature, a human forager who knows what he or she is doing, can collect mushrooms for food and create appetising meals.

In researching fungi, I found, to my horror that my recently planted Rhododendron. ponticum (the common rhododendron) was carrying a harmful fungus as well as itself being an enormous threat to so much I hold dear in my environment.

It grows particularly well in this climate and acidic soil and we often have high humidity. These elements are found predominantly on the west of Britain and Ireland. An association with a mycorhizal fungus enables it to assimilate nutrients more effectively than associated species.

Now there is a new concern that the plant is host to two deadly new plant diseases from the phytophthora fungus – known as the plant destroyer. Phytophthora ramorum was blamed for a plague of sudden oak death in California in the 1990s. “It has been estimated that within twenty years phytophthroa could be in every garden in the UK and have a severe impact on our lowland and upland heath.”

I have had to dig out my rhododendron. Another danger this toxic plant threatens to do is to potentially grow and extend itself down into the nearby burn. Over the years it could cause the death of water voles, trout and river bank creatures, flora and fauna. I could not have had that on my conscience. Understanding about fungi has made me think of the Chinese concept of the two opposing principles in nature: Yin and Yang.

“Yin and yang are opposite in nature, but they are part of nature, they rely on each other, and they can’t exist without each other. The balance of yin and yang is important. If yin is stronger, yang will be weaker, and vice versa. Yin and yang can interchange under certain conditions so they are usually not yin and yang alone. In other words, yin can contain certain part of yang and yang can have some component of yin. It is believed that yinyang exists in everything.”
From Jun Shan

Lichen

No wonder I never saw Lichens when growing up in Leeds, a city of black soot which dirtied clean washing on the line and made most of the population ill with respiratory disease. Here I see plenty of lichens. Wherever pollution increases so the lichens reduce and die. Well, I can’t imagine Leeds before pollution. Here in the Scottish Borders the air is clean and I know so, because lichens are wonderful indicators of air quality. My asthmatic condition has virtually cleared up since we came to live here, though I have to manage it still with inhalers.

A Lichen is fungi and alga in a symbiotic relationship.

First, an alga is like a plant, but not a plant. It is able to photosynthesise, but it is not as complex as a plant. Each has a nucleus surrounded by a membrane in which are organelles which manufacture and store important chemical compounds used by the cell – these are named plastids. The plastids are responsible for photosynthesis. Plastids are thought to have originated from endosymbiotic cyanobacteria. The symbiosis evolved around 1500 million years ago and enabled eukaryotes to carry out oxygenic photosynthesis.

We know fungi cannot photosynthesise.

Lichens are a mutualism formed between fungi and blue-green alga. Alga (called the photobiont or phytobiont) and fungus (called the mycobiont), result in a form called a thallus (plural: thalli) that is completely unlike either of the two.

There are three types: crustose, foliose or fruticose. The first cannot easily be removed from the bark or rock it is attached to; the second is a leaf-like structure, often found growing on a forest floor; the third is like a tiny tree.

One way they reproduce is to separate a piece of the thallus containing both alga and fungus and send it off by wind or water to develop in a new place. This kind of reproduction is common among lichens and generally effective. Those with structures known as ‘fruit bodies’ forcibly discharge tiny spores to a height of a few millimeters where they have a good chance of becoming airborne. Reproduction by spores is a risky business as, on landing and germination, they need to meet the right algal partner before they can form a new lichen.

The oldest certain fossil lichen is Early Devonian (about 400 million years old) from the Rhynie Chert, near Aberdeen, Scotland (Taylor et al. 1995). Scotland has an amazing diversity of lichens, with just over 1500 species. Clean air, diverse habitats, relatively cool summers and mild winters all contribute to this diversity and abundance. Scotland is important for lichens on a European and even global scale.

The West of Scotland has a unique climate. The land is influenced by the surrounding seas, the warmth of the Gulf Stream and results in a combination of extreme humidity, abundant rainfall, persistent cloudiness, cool summers and mild winters. These conditions are ideal for lichens and many rare types are found only in Scotland.

We face the west and that is an ideal position for the lichen to flourish. We are also close to the edge of glades and woodland margins, so lichens are growing on ground, trees, rocks, fences – everywhere I look.

Some crust-like lichens on rocks have a ‘legendary slow’ growth rate, sometimes as little as 0.1 mm per year. If left undisturbed some of our rock-dwelling lichens may be many hundreds of years old. Even when we have had droughts, though they love wet places, they can survive extremes of heat and cold. We know they can survive ice and snow, and are therefore able to grow here in the mountains.

Scottish lichens are many colours: white, grey, black, yellow, orange, sulphur, apple-green, pink or scarlet. They are completely different from the mosses and liverworts with which they often grow. The majority of mosses and liverworts are green, leafy and photosynthesise their own food.

Lichens find an opening, however, where there has been disturbance perhaps associated with peat cutting, drainage or fire. Drier faces, ridges and baulks of peat are rapidly colonised by a range of attractive species. Particularly noticeable are a suite of red-fruited Cladonia species with common names such as Scarlet cups, British soldiers or Bengal matches. Others have brown fruits and are branched like deer’s antlers, coral, or have fantastic ‘Disney-world’ shapes. Another series, the cup-lichens, again Cladonia species, have fruit bodies resembling trumpets or goblets. These Cladonia are common here.

The Thallus foliose, the pale grey variant, forma herinii, dominates our walls and sycamore bark.

Mosses

Most level ground in the west of Scotland is naturally covered with a deep layer of peat, known as blanket bog.The surface vegetation, a mixture of Bog Moss (Sphagnum). Around here, Sphagnum moss grows with other mosses on the walls creating wonderlands of landscapes in their own right. Close up viewing in the bright sunlight are utterly spellbinding. Amongst them grow lichens too, all adding to the richness of delicate shape and contours, finely integrating, incredibly alive and vibrant, no matter what the weather.

Within a few miles of our cottage, up on top of North Mid Hill and across to the Queen’s Mire, lie upland bogs. Bog mosses are always found where there is plenty of water which is mildly acidic. The bog moss grows to about 20 cm producing simple leaves. As the plant grows taller it dies at the bottom and eventually becomes a material called peat. Bog mosses are exceptional in the amount of water they absorb. Dry bog moss can absorb 20 times its own weight in water. Studies suggest that blanket peat began developing 5000 – 6000 years ago. Upland blanket bogs, like lowland raised bogs, are now protected through their designation as Special Areas for Conservation.

Mires exist as a result of a complex peat-forming system which lie over a particular landform. The rainfall supplies the water directly, and this is known as Ombotrophic. Peat bogs that are ombotrophic have less nutrients and more acidity because of it. Acid rain, caused by pollution containing higher than normal amounts of nitric and sulfuric acid caused by burning fossil fuels, will damage the sphagnum moss development. Every living thing which depend on the mire quality will suffer if polluted water falls in the form of rain, snow, fog, or mist. Britain is internationally recognised for its rare areas of Blanket Mire. Strange, then, that the Scottish Borders Council are even considering a wind farm to be built on the Queen’s Mire, famous historically for where Mary, Queen of Scots fell from her horse in the pouring rain as she tried to ride from Hermitage Castle back to her home in Jedburgh.

Upland raised bog is habitat to a wide variety of flora and fauna. Notable plant species include Bearberry (Arctostaphylos uva-ursi), Dwarf birch (Betula nana), Bilberry and Cowberry (Vaccinium spp), Sundews (Drosera spp) and the sphagnum mosses (Sphagnum spp).

Moss is a valuable addition to the forest floor: as it rots down, it creates a thin layer of peat in which other plants can germinate. It can also provide a habitat for insects and even amphibians: in a dry summer frogs and toads can survive deep down in the damp tussocks of moss.

Every part of the moss is permeated with minute tubes and spaces, resulting in a system of delicate capillary tubes, having the effect of a very fine sponge. The cells readily absorb water and retain it. The water can be squeezed out, but the Moss does not collapse and is ready to take in fluid again. The plant is not dependent on soil water, but also absorbs moisture from the atmosphere, and is laden throughout with water retained in its delicate cells.

Mosses cover our dry stane walls surrounding our cottage, over the old stells (sheep folds or pounds), and on our sycamore and ash trees which stand tall by the burn. I cannot be sure of their names as I need a Hand Lens to look closely at their structure. I have sent for one today so that I can learn more about the mosses in my vicinity.