Every once in a while, a big concept strikes home, creating a damascene like moment. I reckon my heightened awareness of the importance of fungi in the ground beneath our feet, which is outlined below, will prove to be almost as significant to me as when I became switched on to the importance of growing insect friendly flowers all those years, ago after a visit to Monet’s garden at Giverny. Not just for the management of our meadows, but the garden itself. And not just for a more stable, self sustaining ecosystem, but with potential for hugely increased soil carbon sequestration as well. But let me explain the synchronicities which led to this moment, a little more.
The conjunction of 3 recent events made me question some assumptions.
The first was a casual reference by some friends who’d recently been on a city break. The weather had been so enjoyable, they’d covered over 16 km walking on a single day. Did they have a pedometer I asked, naively? No came the reply. An app on the phone in a trouser pocket gave them the tally at the day’s end. As someone who out of choice doesn’t possess a mobile phone, let alone a smart one, I’m clearly missing out on this aspect of life. Though perhaps not quite so unusual – apparently smart phone owner percentages now range from 91 to 95% in the 16 to 34 age bracket, but only about 51% in the 55 to 64 group.
However, much as I do sometimes value Fiona’s ability to work her phone and do all sorts of things on the move, this friend’s casual comment reminded me about just how much data is being constantly harvested by the corporates, and no doubt other agencies (benign or otherwise), from anyone using these devices and other portable gizmos like tablets, which get taken everywhere and are consulted constantly throughout the day.
Huge amounts of money and resources all across the world are being pumped into mining this data, its analysis, and how it can then be used to further influence our behaviour, often in subliminal ways. We’re constantly being told that this is the next big thing which will change how we all live. Technology changes, and rapidly advancing artificial intelligence will apparently create the internet of things, (nearly a billion and a half search options if you should google this term!), which will make the previous worldwide web seem very simple by comparison. I’m personally relieved that currently not quite so much will be known about my daily patterns of life, other than when I sit here tapping at the keys in our cottage bedroom. Though maybe I’m naïve about this.
The second event was reading about the ongoing sea trials of the new British aircraft carrier, ‘Queen Elizabeth’, which last week saw the first American F35 jets land on its very expensive decks. Click here for more from the UK Defence Journal on the £3.1 billion vessel, and the first of these £100m jets which will at last give the UK some naval air power, after a gap of several years. To quote the current Defence Secretary, Gavin Williamson:
“The largest warship in British history is joining forces with the most advanced fighter jets on the planet. This marks a rebirth of our power to strike decisively from the seas anywhere in the world. The historic first landing on the deck of HMS Queen Elizabeth is a monumental moment in our country’s proud military history. It is also a statement of Britain’s determination to promote peace and prevent war.”
Probably very worthwhile expenditure in a world with a currently very strange mix of powerful autocratic leaders in many of the largest countries, but certainly sinking a lot of money into a specific, narrow area of the nation’s life.
The third event which was of piffling significance by comparison was the spring meeting of the Carmarthenshire Meadows Group held about 2 weeks ago in the very rural, musty village hall at Pumsaint in North Carmarthenshire. A couple of excellent speakers – one, Laura Jones, gave a resume of her work on using DNA analysis of pollen samples in honey to monitor foraging preferences of honeybees on the extensive estate at the National Botanic Garden of Wales.
Regular readers will know that for years now I’ve been really interested in what I call “insect friendly flowers”, and have a separate web page on this subject – though it’s long overdue for an update. Indeed, for many years, our garden and meadows have been moved towards creating an environment as rich as possible in flowers which appeal across the whole range of insects.
Laura’s PhD thesis, when completed, will give some fascinating quantitative data insight into honeybees’ foraging choices throughout the season, beginning apparently with predominantly Salix and Acers, then moving on through Cratageus and Malus before other less woody plants like bramble, Rubus fruticosus, play more of a role.
The other main speaker was Dr. Gareth Griffiths from Aberystwyth University talking about grassland fungi. This opened my eyes to the significance of what is almost completely hidden out of sight beneath our feet, yet plays such a significant role in the whole of life on earth.
Gareth has opted to study waxcaps in his research, in part because the global system for designating the marker fungi species of diverse, old grassland (the CHEG system, after the 4 genera involved – Clavaroids, Hygrocybe, Entoloma, Geoglossom) was developed by an amateur mycologist based in Lampeter, West Wales, Maurice Rotheroe. Click here for more on his interesting background – journalist, come naturalist. Gareth was indeed inspired by Maurice, and has kept Wales at the global forefront of knowledge of this subject. Astonishingly though, there are currently no undergraduate degree courses available in mycology in the UK. So, an area of symbiotic biology of vital significance to most plant growth and healthy soil ecosystems, and therefore underpinning much of food production on the planet, pales into real insignificance when global research funds and energies are allocated.
Better to fund all that analysis of who did what, where and when, and make sure one can destroy an enemy should the need arise. Really?
Perhaps the latest alarm call from the IPCC will change minds, though I somehow doubt it. Click here for their summary.
Gareth began by explaining the essence of the carbon cycle which fuels all life on earth, and the critical role that fungi play in this. Here’s a quick résumé.
Plants capture the energy of the sun through photosynthesis and fix it in the form of carbohydrates. Three of these are complex polymers – cellulose, hemicellulose and lignin – which are specific to plants, and form the components of typical plant cell walls (typically in an approximate ratio of about 4:3:3 – depending on plant type). These complex polymers of simple sugars, often with thousands of repeated, but bonded simple components, are sufficiently challenging structures that animals still haven’t evolved a way of degrading these molecules themselves.
In the case of cellulose and hemicellulose, several grass or plant eating animals have evolved digestive systems entirely reliant on microbes – both bacteria and fungi, in their intestines (either in the rumen, or caecum), which can break down the cellulose in plant cell walls into the component simpler molecules, like glucose, which can then be absorbed from the gut and used for animal growth.
Lignin however was a tougher digestive nut to crack, being the hard, dark brown material, which gives woody plants their rigidity. Gareth explained that during the carboniferous period (of about 60 million years duration, and which ended about 300 million years ago), plants evolved lignin, but there was simply no way of degrading it in the earth’s ecosystems. The result being that when plants died the leaf and woody debris just accumulated and gradually built up, in due course becoming the deposits of oil and coal which have fuelled man’s increasing energy demands over the very recent past. As the leaves drop this autumn and the yard and meadows become littered with tree debris, what a sobering thought as to what would happen if this material wasn’t so efficiently recycled out of sight.
Times changed when fungi eventually evolved the enzymes capable of breaking down lignin. A complex soup of various extracellular enzymes, produced principally by white rot Baciomyecetes fungi are now thought to be the principal drivers which degrade the roughly 20% of organic matter in typical soils which derives from all the lignin in plant cell walls – in dead leaves, twigs, logs, and roots. This gradual but continual fungal degradation releases the carbon accumulated in plant cell growth back into simple forms, which are then available for both animal and other plant growth. The carbon cycle is far too complex to pursue here, but click here for a good review by NASA.
Gareth also mentioned that the fruiting bodies of mushrooms represent only about 1% of the total mass of the fungal organism, which has a huge and often very long-lived network of mycelia strands below the ground surface, often itself connecting with the roots of many plants, and involved in complex two-way exchanges of nutrients with plant roots. It’s now widely accepted that probably 90% of plants have root interactions with such AM or arbuscomycorrhizal fungi.
Wales is a global hotspot for grassland waxcap species. I’d always thought that this was a consequence of the very damp local conditions, but Gareth explained that it was also partly because of the hilly terrain and “poor” soils locally, which has meant that areas of the landscape have simply never been ploughed or received fertiliser treatments. Both of which can very quickly completely destroy the underground networks of many of these colourful waxcap fungi. As part of his work, he’s been to visit the longest running ecological survey of grassland at the internationally renowned Rothamsted research institute in Hertfordshire. Here, in the “Park grass plots”, annual monitoring of many distinct plots created from a single meadow back in the 1860’s has conclusively shown that plant species diversity has diminished over the years, and many grassland fungi disappeared very quickly in response to applications of nitrogen, lime or phosphorous. However, amazingly, Gareth still regularly finds, in autumn, fruiting bodies of some waxcap mushrooms on the two control plots which have never received any artificial applications over all these decades. These are nearly unique waxcap records, from the counties surrounding London. They have simply been wiped out by “agricultural improvements” from all other agricultural land.
Well, it seems that in terms of total soil organic carbon storage, nothing apparently beats diverse old permanent grassland, managed as it typically is with livestock grazing and maybe a hay crop. Even converting such land into forestry, which is currently happening apace in many areas of Wales, will reduce the ability of a given acreage of soil to sequester carbon. In major part, this ability to store carbon, hidden, and out of sight beneath our feet, is exactly what the grassland fungi are doing in their complex interactions with plants’ roots. Meanwhile, scientists are striving to develop technological solutions to try to capture the increasing levels of carbon dioxide in our warming atmosphere, and store it underground. Without apparently much success, so far.
Finally, and most intriguingly, Gareth mentioned some of his research looking at the concentrations of the heavy isotopes of carbon, C, and nitrogen, N, in different animal and fungal tissues. The higher up the food chain an animal is, the greater the proportion of these heavier isotopes found in tissue samples. For example in a marine environment the plankton will have low levels, plankton feeding shellfish will concentrate these isotopes and have higher levels, fish which eat shellfish higher levels still, and a predator like a Polar bear will have the highest levels of both heavy N and C, in their body tissues.
Gareth found that most saprophytic fungi, which help to decompose plant material do indeed have higher levels of the heavy carbon isotope, but much to his surprise, the waxcap mushrooms have dramatically higher heavy nitrogen levels. Gareth thinks this implies that these fungi have a role in decomposing decaying animal matter, hence are saprobic, but as yet he has no conclusive evidence of how they are doing this or what they are feeding on. Click here for more.Part of the problem with researching these fungi, is that it’s proved almost impossible to cultivate the fungi in the laboratory, in spite of years of trying. A marked contrast to many of the other fungi which form part of an approximately £42 billion industry serving human consumption. By coincidence Kew Gardens have also very recently released a review document on the state of the world’s fungi. Click here for an interesting read.
There is a great review article, co-authored by Gareth and outlining aspects of grassland fungi management which was published in British Wildlife magazine which you can read by clicking here.
My own excitement with finding grassland fungi in most of our meadows as we’ve changed the land management over the last few years, is now matched by thoughts about what gardeners can learn from some of these concepts, about the huge role that often hidden fungi will play beneath the soil surface in our gardens, and how we can best nurture and respect these.
Are applications of high nitrogen material, or high phosphorous material always a good idea, since they will severely impact on many fungi?
Is soil disturbance through digging rational?
As our garden moves in many areas into a more mature, settled type of semi-woodland ecosystem, topped up with natural leaf litter, and the occasional sprinkling of wood ash or dry seaweed, I’m convinced that beneath the soil surface, increasingly complex webs of activity between fungi, and bulb, plant and tree roots are indeed creating an incredibly complex internet of all living things – whether I fully understand it, or not. Should you google this term, you’ll find a cool half a billion search options, including an article, click here, which uses the phrase in a different, though intriguing sense, and explains that we’re on the cusp of availability of portable devices enabling anyone to genome sequence any organism anywhere, and upload the data to the cloud.
It’s an appropriate prime time of the year for web watching in the garden, and also the meadows, though inevitably here, the numbers of spiders are far fewer than seem to inhabit the flower filled confines of the garden. How any insects manage to escape capture is a mystery when one sees the extent of complex means of entrapment hanging over the foliage, once highlighted with morning dew.
The combination of now having a honeybee hive on site, and a formal transect walk for counting bee numbers should yield some interesting data of my own on preferred flowers through the seasons to update my previous anecdotal observations. Although an early idea is that it’s tricky to work out whether it’s the sheer numbers of a particular flower which makes it a hit with the bees, or the particular flower type. Since the flowers we’ve planted, or allowed to grow en masse, have tended to be those which, years ago, I assessed as getting frequent visits from many insects.
So this week, the real stars have been Persicaria vaccinifolia, Anemone japonica, as a simple unnamed thuggish pink form, Clematis tangutica, Gernaium procurrens, and in the meadow, Fox-and-Cubs, Pilosella aurantiaca. As a simple thought to leave you with, the thug like Geranium procurrens, which thrives and has spread along the large bank behind the house, stabilising the shale surface on the process, begins blooming in early August most years and continues until the first frosts – sometimes into November.
A quick estimate of current flowers on this patch which originated from perhaps just 3 plants many years ago, came out with a figure of about 5,000 blooms open at any one time. Though an individual flower is fairly short lived, each of the multiple stems has around 10 spent flowers on it. Thus this native of the Himalayas, which would probably be a thug in good soil, is a tremendous resource, for a diverse range of insects, on a difficult to manage site. Perhaps even exceeding a modest suitable tree, in providing nectar and pollen in quantity over a prolonged period. And at the fag end of the season, an obviously easy to locate beacon for those bees to reach, when weather conditions are suitable.