Back to one’s roots? Some of the effects of agriculture are very obvious, such as the vast areas of land now covered by monocultures of wheat or oil seed rape.  The expansion of mechanised agriculture has resulted in significant reductions in biodiversity, for example, through the loss of hedgerows and ponds (see the post on ghost ponds in Norfolk).  However, agriculture has others effects that are not quite so obvious.   Soils are ‘filled’ with roots, and roots help engineer landscapes.  They help: break up bedrock, improve permeability of the soil to water  stabilise the soil,  store carbon transport water and minerals to the plants.   They have been doing this for millions of years since the colonisation of land by plants. Now, research by scientists in the United States, has shown that the roots of agricultural crops are significantly less deep than those of  the  natural vegetation in an area.  Indeed, the root depth may be shallower by some 60 cm, compared to the natural root systems of an area.  If the soil is less root material then there is  decreased carbon storage,  reduced nutrient recycling and  possibly reduced soil stability.   Whilst there are some areas where “woody encroachment” is occurring (for example, shrubland taking over in some grasslands and forest advance into regions of tundra so root depth is increasing) -  the onward march of agriculture is dominant. Full details of this analysis / research : https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2022EF002897 Shrinking in winter Recent research has shown that some small mammals (like moles and shrews) shrink in size during periods of cold temperature.   This shrinking is thought to be a response to cold temperature rather than lack of resources.   This change in form has been known for some 70 years and is referred to as Dehnel’s phenomenon.  Professor Dehnel observed this change in form in shrews [in Poland in 1949].  However, shrews have a short lifespan so an extended studied of this phenomenon with these animals was not / is not possible.   Recent studies by German researchers have focused on moles, who can survive harsh winters by becoming  smaller.  It is thought that this reduction in size enables energy savings.  According to Dr Dina Dechmann this reduction in size comes at a cost, as the animals’ cognitive behaviour is affected. Further information here : https://royalsocietypublishing.org/doi/10.1098/rsos.220652 Farming and sustainability With the expansion of farming, less and less of the land is available for our native plants and animals,  Hedgerows and ponds have been lost / removed, natural habitats have been reduced. The government has produced new guidance on environmental land management schemes (ELMs).  That is subsidies that will be paid to farmers if they help promote and protect nature and improve the environment (e.g. using less insecticide and reducing pollution). There would be payment /subsidies for some 280 measures, for example : Creating fenland from lowland peat Maintaining sphagnum moss Creating land that could produce organic fruit Establishing a skylark plot Adding organic matter to the soil Creating green cover over winter (on 70% of the land) Welcome as these measures might be, there is criticism that they favour big arable farmers and do not really help those working on more marginal land (such as upland and moorland regions). Further information available here. Trees - From Root to Leaf For those who like their trees, here is a new book about them.  Written by Paul Smith -who was head of the Millennium Seed Bank of the Royal Botanic Garden, Kew.  Not read or seen a copy but the Sunday Times comment "'Stunningly illustrated and detailed ... a celebration of all things arboreal, from the seeds, leaves, flowers and fruit to the diversity of trees and how they have influenced art, culture and science' suggests that it might interest.  See "https://press.uchicago.edu/ucp/books/book/chicago/T/bo186012850.html"  

In recent times, we have heard much about various initiatives to plant more trees, such as The Queen’s Green Canopy tree planting project to mark the platinum jubilee. Tree planting is part of the government’s plan to mitigate certain aspects of climate change as the trees will absorb carbon dioxide from the atmosphere, which is one of the principal greenhouse gases.  Once absorbed and used in photosynthesis, much of this carbon is then locked away for many years in the form of complex compounds, such as cellulose and lignin. The peak of carbon dioxide uptake by UK woodlands and forests was estimated to be just under 20 million tonnes in 2009.  However, since that time the amount has actually declined.  Many of the conifer plantations that were planted back in the 1970’s and 1980’s have now been felled / harvested, so they no longer contribute to the uptake of carbon dioxide.  It is important that these clear felled areas are replanted and tree cover restored; indeed, in places increased.  Planting rates have risen in Scotland but the performance by the rest of the UK is somewhat limited.  Even with new planting, it takes time for such new forests / woodlands to reach the CO2 absorption levels seen in the 2000’s. Continuous cover forestry (CCF) is a different approach to woodland forest management; it seeks to avoid clear felling and  promotes a mosaic of trees by age and species. There are a number of factors that influence new planting, such as the availability of land.  Using high grade agricultural land for tree planting would affect targets for increased agricultural productivity and domestic food supply.  Also, with climate change and the increasing number of extreme weather events (storms, flooding, drought etc) greater thought needs to be given to risks such as forest fires.  Recent months have demonstrated the ferocity of forest fires in France, California and Portugal.  We cannot assume that the UK will be exempt from such events.  Similarly, we have witnessed powerful storms (such as Storm Arwen) which felled many thousands of trees (and impacted on public services such as electricity and train travel).  The warming climate is also associated with ‘new’ diseases and parasites in our woodlands and forests. New planting needs resilience ‘built in’ to the plan. The Environment, Food and Rural Affairs Committee in its recent report (2021/2) has made a number of important comments in relation to tree planting in the UK, notably : It noted that the Forestry Commission had said that nurseries in the UK will struggle to expand production to deliver the number of young trees required for the Government to achieve its planting ambitions. There is a lack of a sufficiently skilled and large workforce to achieve England’s tree planting ambitions. To meet the Government’s tree planting goals, the UK will need to import seeds and young trees (until domestic capacity increases); and this carries the risk of the introduction of pests and diseases.  

In recent years, there have been a number of initiatives to plant millions of trees, both here in the UK and in many other countries.  For example, http://www.stumpupfortrees.org/bryn-arw-common-pilot-plant/ https://www.nationaltrust.org.uk/press-release/national-trusts-plans-for-20-million-right-trees-in-right-places-take-root https://queensgreencanopy.org https://onelifeonetree.com https://earthwatch.org.uk/get-involved/tiny-forest?gclid=EAIaIQobChMIiqyVxOvA9w https://earthwatch.org.uk/get-involved/tiny-forest The trees are not being planted to increase timber production. They are to help offset global warming as trees take up carbon dioxide through photosynthesis, so they remove this greenhouse gas from the atmosphere thus helping to offset global warming. However, planting just ‘any old tree’ is not going to solve anything, so scientists from Kew Gardens (RBG Kew) and Botanic Gardens Conservation International (BGCI) have set out ten ‘golden rules’ for reforestation. The "Kew" guidelines have been summarised as below : Protect existing forests first Put local people at the heart of tree-planting projects Maximise biodiversity recovery to meet multiple goals Select the right area for reforestation Use natural forest regrowth wherever possible Select the right tree species that can maximise biodiversity Make sure the trees are resilient to adapt to a changing climate Plan ahead Learn by doing Make it pay However, fast as trees are being planted in many places, there have been substantial losses of forests and woodlands in recent times.  The blog has reported on the extensive fires in Sweden, and the Mediterranean.  The recent fires in boreal regions have been extensive and worrying - they have affected Canada, Russia and Alaska.  In the last year, Russia lost some 6.5 million hectares of tree cover.  Boreal forests are often portrayed as vast tracts of ancient, untouched wilderness. Whilst it is true that the boreal region is in itself ancient, the boreal forests are generally composed of relatively young trees trees (as compared to the oaks etc. found in temperate forests and woodlands). Historically speaking, boreal forests have renewed themselves through natural regeneration, after fires.  But now with climate change and rising temperatures, conditions are drier and the fires are more frequent and more intense.  There is also a problem of  damage by insects. The loss of forests in tropical and sub-tropical regions has been a cause for concern for many years, not only because of their importance in generating oxygen and removing carbon dioxide but also as they represent areas of great biodiversity.  Sadly, the loss of such forested areas continues, despite the commitments made at COP26  (where some 141 countries committed to "halt and reverse forest loss by 2030.").   [caption id="attachment_38123" align="aligncenter" width="700"] clear felling in progress[/caption] Forest / tree clearance occurs as a result of clearance for activities such as cattle ranching or the production of palm oil.  However, as a result of the events in Ukraine / Russia the availability / prices of certain oils is now high.  This is also true for palm oil so the ‘temptation’ to convert forested areas into palm oil plantations is significant.   Whilst there is clear evidence that various countries and governments are involved in the creation of woodlands & forests through tree planting initiatives, and working to reduce the loss of primary forests to agriculture or timber extraction, there is concern that nature itself is beginning to work against us. Changing weather patterns, increasing temperatures and extreme climate events are already affecting many forested ecosystems.  

Perhaps it all started with a "No-shave November" (or "Movember") when men realised that they could go for a month without shaving and no one would mind.  It may also have been good for them as they thought more about men's health and they let nature take its course.  A few years later people started wondering about other habitual cutting, such as mowing their lawns religiously.  "No Mow May" was invented in 2019 by Plantlife with the idea that less cutting of grass would allow wildflowers to flourish.  The official reason for this concession to conservation was to allow the wild flowers and pollinators to thrive, but it may also have become popular because it allows maintenance teams to work a bit less hard during May.  In any event it's now so popular that about 36% of lawn owners now join in every year.  But it's spilled over well beyond just the month of May - many owners of lawns have questioned whether they really want so much short grass when alternatives are more interesting - and better for wildlife.  Even at the 2022 Chelsea Flower show there were several gardens demonstrating rewilding. So rethinking the scorched earth policy has now spread from men's chins to gardens and parks - but will it spread further?  What about our hillsides? For eighty years we have been intensively grazing these with sheep and cattle as if our lives depended on it - which maybe they did in 1942, when war-time convoys of food from the US were being torpedoed.  Even after grazing ceased to be a necessity sheep continued to dominate our hillsides with grants to sheep farmers making it profitable to use their four-legged lawnmowers at scale.  Farmers even grubbed out hedges in the 1970s, described by Oliver Rackham as the locust years, which made the countryside look even neater and tidier.  According to DEFRA there are currently about 32 million sheep in the UK, a third of them in Wales.  Land used for rough grazing and grassland makes up about 50% of the UK's total land area.  So for several generations now the UK has used half of its land to raise animals for eating, but times are changing rapidly.  Whereas those with meat-free diets used to be a tiny minority their numbers are growing rapidly - already at least 14% of the population is meat-free and for those of university age (18-23) the number is up to 25%, and rising. The combination of reduced demand for meat and increasing awareness that we can happily stop cutting the grass is prompting a rethink of how we use the British countryside.  Much of the grazing land is not suitable for growing agricultural crops so that leaves owners wondering what to do with their land.  Some are choosing rewilding in various ways but usually with far fewer grazing animals, longer grass and more wildflowers. [caption id="attachment_38426" align="aligncenter" width="600"] 'rewilding' of roadsides and verges[/caption] Others are planting trees and creating new woodlands.  Where the land is sold it's often to people who want to plant trees or simply to fence out sheep and allow "natural regeneration" allowing trees to self-select and grow on their own.  It's an appealing project for many families to take on 5 acres of grazing land, plant trees and convert it into a wood of their own. This re-evaluation of how grazing land is used is happening right across the world as plant based diets become more popular and there is potential to re-establish wilder habitats.  It's good for carbon emissions - not only because woodland fixes carbon but also because rewilding cuts the number of grazing animals releasing methane: belching by sheep and cattle creates a third of the total emissions of UK agriculture. Despite this, there may be resistance from the powerful National Union of Farmers which mostly represents bigger farmers and which promotes farming as an industry.  Farmers already complain about reductions in headcounts of livestock - since the peak in 1992, sheep headcount is down by about a third.  But it's also about the way the grant system is structured - millions of sheep only exist because of the farm payments, financed by taxpayers, and the condition of receiving these annual grants is that "unwanted" vegetation and wild plants have to be removed.  So even if the sheep don't chomp up biodiversity the farmers have to do it to get their grants. [caption id="attachment_21282" align="aligncenter" width="600"] Sheep grazing around solar array[/caption] Even beyond this suppression of diversity, sheep and cattle are damaging in many other ways such as compacting the soil which contributes to flooding and droughts. Meanwhile the number of men keeping their beards after no-shave November has increased and there are more gardens and parks with wild meadows so maybe the much bigger revolution in rural land use might follow. Governments have had it within their power for decades to reform the grant system but real change may be driven by people's behaviour - eating less meat and planting up their own woodlands.

How many trees are there in the world? When Thomas Crowther and Henry Glick used geospatial data in 2015 to estimate the number of trees in the whole world there was good news and bad news. Good news that there were several times as many trees as anyone had previously realised (total is about 3 trillion) and bad news that the number was declining faster than expected.  The calculation was done partly to establish a baseline so that tree-planting efforts could be put into perspective - the UN's Billion Tree Campaign managed to plant about 15 billion trees over 10 years in virtually all countries across the world (193).  But whilst these numbers sound large this has only added 0.5% of trees so much more needs to be done if we want to reduce the damage humans have done to tree numbers - before humans emerged there were about twice as many trees as there are now.  Perhaps that's why the Trillion Tree Campaign was launched in 2018 in Monaco - a principality covering only two square kilometres and almost bereft of trees. More locally, the UK has a tree count of about 3 billion trees - about 45 trees per person - calculated by analysing aerial photos and estimating tree numbers as was done under the UN's Plant for the Planet project.  There is some flexibility on the definition of what counts as a tree - and this assumes you don't count all the self-sown seedlings or bushes, which some might consider as trees.  This number is dominated by a few species - of the commercially grown plantations in Scotland, for example, 60% of the trees are Sitka Spruce so they don't add as much to biodiversity as a wider species mix would do.  And those 45 trees per person is a bit misleading in that there may be nearer to  400 trees per person in Scotland  - it is more sparsely populated with less than a tenth of the UK's population but almost half the trees. The UK's tree-planting is put into perspective by comparing the relative numbers - the UK's 3 billion trees amounts to one thousandth of the global total whereas nearer to 1% of the world's population is British - so by comparison with the world's average, on a per-person-basis a Briton has a tenth as many trees as the average citizen of the world.  The most densely tree-ed parts of the world are the tropics where 43% of the world's trees are growing. At a recent general election (2019) the political parties were competing to promise how many new trees they would ensure were planted - the Liberals and SNP each promised 60 million a year, whereas Labour said they would do 100 million every year.  A more realistic Conservative party promised 30 million trees every year which would equate to about 15,000 hectares (or 6,000 acres).  Despite this lower manifesto promise, the government is really struggling to achieve even that amount - but if they did reach that target every year for 10 years it would add 10% to the UK's tree cover. There is ample scope for more trees with the UK having only 13% tree cover, but are there are other ways to increase the numbers beyond tree planting? Trees will naturally establish themselves if they are not cut or grazed - perhaps one thing the government could do would be to reduce the number of wild grazers - mostly deer and sheep.  

There’s a seemingly endless stream of bad news in the world: the coronavirus pandemic has forced us stay inside more than we’ve ever had to in our lifetimes, and there’s the ever-impeding threat of the climate crisis. Our collective mental health is suffering, and more than ever we’re looking for anything that can provide some alleviation from this.  The government recently found that almost half of the UK’s population say they are spending more time outside than they did before the pandemic, so it’s clear that green spaces are more important than they have ever been for both our own wellbeing and the wellbeing of our planet, which really begs the question ‘why not plant more trees?’  Why is tree planting good for the environment? Forest ecosystems are one of the world’s greatest carbon sinks in existence. They hold up to 45% of all the carbon stored on land, as well as being home to 80% of the animal and plant life on land. Maintaining our forest ecosystems could be one very large step towards solving the climate crisis; and though this won’t be enough on its own, it’s definitely a good place to start. On a smaller scale, one hectare of young woodland  has the ability to lock up over 400 tonnes of carbon.   Imperial College estimates that a tree planting initiative on a worldwide scale could capture the equivalent to one decade’s worth of carbon emissions (at current rates) by the time these forests reach maturity, or up to 1/3 of all emissions from human activities that remain in the atmosphere since the Industrial Revolution. How can tree planting can benefit you? Local tree planting initiatives are an excellent means of drawing a community together. Forest For Peterborough, a tree planting organisation in the UK, started in 2010 with the aim to plant 230,000 trees by 2030, and at the same time provides a space where the community can come together and learn how to make responsible and sustainable choices. In 1980 Edward O Wilson, American biologist, popularised the term biophilia to describe the innate connection people have to the natural world, and it’s true that we as humans seek and crave the comfort of the natural world, particularly in times of stress. The UK government estimates that visits to UK woodlands have saved an estimated £185 million in mental health treatment and costs. At the same time, street trees in rural areas are thought to have avoided £16 million in antidepressant costs, so why are there not more trees being planted in rural and urban areas? More local tree initiatives like Forest For Peterborough could both help save people’s mental health and help the UK government reach their target of becoming carbon neutral by 2050. Planting trees can also help with our physical health. It goes without saying that having poor mental health can begin to have an impact on our physical health, and vice versa (in fact, loneliness has the same affect as smoking 15 cigarettes per day), and having green spaces near our living areas helps to improve our attention and creativity. Walking amongst trees even boosts our immune system and reduces our cortisol levels. It’s also been shown that in areas affected by tree loss, women have a higher risk of cardiovascular disease (222,000 hectares of green space have been lost to urban sprawl between 2006 and 2012 in the UK) and senior citizen’s survival rate is 17% higher if their residence is within walking distance of a green space.  Planting trees can even help your wallet, too (maybe money does grow on trees!). Aside from saving the UK government millions of pounds in mental health costs and the projected costs that could come with the climate crisis in future, planting trees next to buildings can reduce the buildings’ energy consumption by up to 26%. This lowers the buildings’ internal temperature by 4 degrees in the summer and increases it by 6 degrees in the winter, so there’s less of a need for central heating and cooling systems (and of course prevents further emissions into our atmosphere). House prices rise by 9 to 15% if they’re near trees: they add to the aesthetic value of a neighbourhood, make people feel safer, and have been proven to lower crime rates. Why not plant trees? So, why plant trees? If planting trees for the sake of the planet isn’t enough of a reason, then there are plenty of ways tree planting can help you and your community. If you’re looking for tree planting opportunities there are plenty of events coming up, such as National Tree Day, which this year will be celebrated on July 31st. For the Queen’s Platinum Jubilee a tree planting initiative - The Queen’s Green Canopy- will encourages people across the UK to 'Plant a Tree for the Jubilee.’  Tree planting land for sale is available through the Woodlands website- let’s get planting!

In the C19th, many objects were made from ivory.  The ivory came from the slaughter of elephants.  As elephant populations fell, so the search for a suitable substitute began.   Celluloid was one of the first materials used but it was easily combustible. It was soon replaced by other materials like Bakelite,  this was the first entirely synthetic plastic.  It was made from phenol and formaldehyde.  It was used for toys, radios, telephones etc.   Bakelite  was tough, heat resistant and  did not conduct electricity.  Other materials followed, and many different plastics are produced today; for example, polyethylene (which is widely used in product packaging) and polyvinyl chloride [PVC] (which is used in construction and pipes because of its strength and durability).  The trouble is that plastics are just so useful.  Plastics are cheap, lightweight and durable.  Durability is a good quality when the plastic is being used but not when it is discarded, for example, into landfill where it may take centuries to degrade.  Sadly, many consumers leave empty bottles / containers / wrappers in the streets, on the beach, at picnic sites etc.  As most plastics are made from fossil fuels / oil, the manufacture of plastic is also a driver of climate change. Since the middle of the twentieth century, it is estimated that some 8.3 billion tonnes of plastic has been produced. Sadly much of this has ended up in landfill, in rivers, the soil, and the oceans - with significant effects of wildlife. Plastic pollution is ubiquitous. For example, the Great Pacific Garbage Patch, which is a collection of large areas of plastic and other debris in the North Pacific Ocean. It has been estimated that it contains some 1.8 trillion pieces of plastic .  It is a serious threat to marine life such as whales, sea turtles, fish, and birds.  Plastic items are discarded with little thought to the consequences.  Bottles etc can end up as traps for many animals and a few years back we (at woodlands) found a child’s plastic boat dumped in a woodland (see featured image above).  Sometimes, we see the distorted remains of plastic tree guards ‘strangling’ young trees. Plastic carrier bags (sometimes filled with dog faeces)  can end ups suspended from trees / shrubs in woodland, or caught on wire fencing, waving n the wind. Discarded plastic items come in all shapes and sizes; those that are 5mm or smaller are termed “microplastics.”  Microplastics come in part from larger plastic pieces that degrade into smaller pieces; but also from microbeads.  Microbeads are very small pieces of polyethylene plastic that are added to health and beauty products, such as some skin cleansers and toothpastes. Now microplastics are to be found everywhere from deep oceans, to Arctic snow and Antarctic ice.  They are found in foodstuffs and drinking water.  One investigation found that if parents prepare baby formula by shaking it up in hot water inside a plastic bottle, their child might swallow tens of thousands of these microplastic particles each day.  The movement of these particles through ecosystems is  graphically summarised in this article.   There is currently much discussion and research about how these microplastics will impact on the environment and different organisms, including us.  Because they are so small and to be found widely in the environment,  they enter organisms and food chains.  Apart from the plastic in these particles, they may also contain chemical residues of  plasticisers, drugs, and pharmaceuticals, and heavy metals may stick to them.  Sometimes, sewage sludge may be used as fertiliser and this can contain nanoplastics.   Also, treated wastewater is used for irrigation  purposes and this again may be a source of plastic.  Research indicates that earthworms in microplastic ‘enriched’ plant litter grow more slowly and have a shorter life span, and there is evidence that the gut of earthworms becomes inflamed after exposure to microplastics.   Earthworms are important in aerating the soil and transporting materials such as dead leaves from the surface to deeper in the soil, they also 'inadvertently' transport micro-plastics.  Springtails, a group of soil micro-arthropods (Collembola) can also help move micro-plastics in the soil.  The movement of microplastics through the soil makes these materials ‘accessible’ to other soil dwellers but it is not clear if they pass along food chains (as has been the case with pesticides). Whether nano-plastics are taken up by or affect plants - again is not yet clear.  However, the chemicals released by plastics such as phthalates may taken up by plants. There is a significant risk of physical and physiological damage to organisms and ecosystems by these micro-plastics *. The particles also get into the human body and the consequences for our health are, as yet,  unknown. further information on nanoparticles etc : https://www.sciencedaily.com/releases/2022/04/220420133533.htm

We tend not to think about soil very much, except perhaps when digging over a tough patch of weeds in the garden or if we see it being stripped from dry fields in a strong wind.  We take soil for granted though we rely on it for our food - almost totally.  Soil is a very thin layer covering the outer surface of the Earth.  The earth’s crust varies in thickness from 3 miles in oceanic regions to 30 miles in continental areas - by comparison most soils are shallow and have little depth. Sadly, the earth’s soils have been neglected and squandered throughout history.  In America and Canada, deep ploughing of the prairies and subsequent drought left the ‘unanchored soil’ exposed to wind erosion. Read more...