It is depressing to pick up a paper or turn on the news to be met with a catalogue of distressing and difficult stories.  There is also the overarching problem of global warning and climate change.  Only recently, there have been reports of flooding in Sydney after torrential rain, fires are springing up again in Colorado and other States, and India experienced a heat wave (combined with a drought), with some cities experiencing temperatures of 40o+C.  This has resulted in the deaths of individuals, and as the heat wave occurred in the final weeks of the wheat growing season it has killed many crops before harvest.  In Balochistan, the peach and apple harvest has been severely impacted. Here in the UK, there are a number of problems, indeed we have been described as “one of the most nature-depleted countries in the world”.  We have lost plant and animal species, such losses could lead us into an ‘ecological recession’. This occurs when ecosystems systems lack the diversity needed to function well. Much of the damage to (or loss of) our ecosystems is associated with the industrial revolution followed by the  intensification of mechanised farming. The 1950’s and 1960’s witnessed the loss of vast tracts of hedges and the removal of small copses to increase the area for farming / food production, and allow the use of heavy duty mechanised machinery.  There was also the extension of road networks - motorways etc. and urban sprawl /development.  Though woodlands and forests were being eroded long before the industrial revolution; woodland, forest and pasture covered much more of the land than now. There were areas of ‘wilderness’ that were home to animals and plants that have long since gone or are now very rare - ranging from wolves, bears, to beavers and red squirrels. Whilst woodlands were and are havens for many plant and animal species, meadows and pastures have suffered too.  The PlantLife charity has suggested that the UK has lost some 97% of its wildflower meadows during the course of the last century and what remains could be under threat. Lowland meadows are rich sources of biodiversity, both plant and animal, they also store carbon in the soil and ‘knit’ the soil together, so that it is not subject to erosion. [caption id="attachment_38489" align="aligncenter" width="700"] A meadow, partly mown and partly 'wild'.[/caption] Many species are dependent on these habitats, but with the expansion of agriculture and construction of motorways - the landscape has become fragmented and many species cannot across the formidable barriers.  The Scottish primrose is now only to be found on the north coast of Scotland and Orkney, and some orchids are described ‘as just hanging on’.  Species like the common blue butterfly is reliant of bird’s foot trefoil, Greater Bird’s-foot-trefoil, Black Medick and white clover for food for its caterpillars.  The great yellow bumblebee is sadly now one of the rarest British bumblebees. It is limited to flower-rich areas in the Orkneys, Caithness and Sutherland. It is particularly associated with red clover. It is a large species, and was once widespread across the U.K. Creating space and opportunities for wild flowers has been PlantLife's foremost objective from “No mow May”, “Save nature on our roadside” (see the woodland blog here and here) ’Fight for sites” all of which aim to increase the number of sites for wild flowers and their pollinators to flourish.  The Scottish Government has been helping establish wildflower meadows at some of its national nature reserves - notably St Cyrus, Flanders Moss and Forvie, and they are working with PlantLife to create an action plan for Scotland’s grassland.  It is keen for farmers to be involved, offering areas of wild flowers on their farms.  By increasing the areas in which wild flowers (and their associated insects) can flourish, the connectivity can be restored (at least in part).  The creation of biological corridors allows plants and animals to move, which is particularly important in these times of climate change.  

If bumblebees are exposed to heat stress during their development (they go through four stages : egg / larva / pupa / adult or imago) their bodies develop asymmetries.  The wings in particular are affected, so the left and right wing are shaped differently.  This asymmetry can be measured and has been used by a team from the Natural History Museum and Imperial College to investigate how changing climate over time has affected bees. They investigated four species of bumblebee [Bombus hortorum, B. lapidarius, B. pascuorum and B. muscorum] in museum collections that dated back to 1900 CE.  The bees were ‘held’ in collections at various museums  [Natural History Museum (London), National Museums Scotland (Edinburgh), Oxford University Museum of Natural History, Tullie House Museum and Art Gallery Trust (Carlisle) and World Museum (Liverpool)].   [caption id="attachment_38920" align="alignleft" width="300"] Landing[/caption] Using digital images of many bees collected at different times over the last 130 years, they measured the asymmetry of their wings.  The data from these measurements were then correlated with information about annual rainfall and mean annual temperature in the year the bee was collected.  It became clear that wing asymmetry was associated with hotter and wetter years; and that each of the bee species displayed greater asymmetry, hence stress, in the second half of the twentieth century.  As hotter and wetter conditions are predicted to become more frequent with climate change, it is probable that bumblebees will experience greater stress, indeed they may be in for a ‘rough time’ as this century progresses. Apart from investigating wing asymmetry, the team used a leg from some of the historical specimens to analyse the DNA / genetic make-up of the bumblebees (B. lapidarius).   With the DNA data from these bees (dating aback over a century),  the Natural History Museum and the Earlham Institute were able to construct a ‘reference genome’ - a standard against which they can see how bee genomes change over time.  This may ultimately reveal how bees are adapting (or not) to a changing climate / environment.

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.  

Looking around the garden this morning one might be forgiven for thinking that autumn is already here.  Several trees seem to think the short days of autumn have arrived and are preparing to shed their leaves. Certainly the walnut and hazel are of this opinion.  However, other signs indicate that this is not the case, my twenty year old cedar has died, as have several Cryptomerias and other conifers - this despite assiduous trips with the water can.  In fact, the plants are responding to this summer’s weather, a long period without rain (or very little) plus the very hot weather that we have experienced; particularly in the South and South East.  The plants are not reacting to any changes in day length but to drought. Plants detect changes in the photoperiod they experience through their phytochrome system; under normal circumstances their biological clock will tell them when to prepare for winter.   Whilst many well established trees and plants with extensive root systems can withstand a period of drought, younger plants or those in poor or freely draining soil are likely to die.  Such plants simply cannot take up enough water to replace that lost through transpiration; that is, water evaporation through the stomates (pores) in the leaves.    The intensity of the heat this year coupled with the reduced rainfall has affected many plants and trees and it may be some time before we see the full effect of this summer’s weather.  Beech trees suffer more during periods of droughts because they have shallower roots, while oaks reach moisture deeper in the soil and continue to grow.  In the drought of 1976, many beech trees died and survivors often exhibited reduced growth some 40 years on*. Some plants respond to drought stress by bringing forward their reproductive process, so that fruits and seeds are produced early.  This is an attempt to ensure the survival of the species for when conditions are more favourable to growth.  The Woodland Trust, noted for its phenology records, recorded ripe blackberries in late July (lots of reports on its page on Facebook).  Hawthorn, Rowan, Holly and Elder have all been recorded as fruiting earlier this year.  This was true of the filbert in my garden this summer.  This earlier production of fruits and seeds may have ‘knock on’ effects on the wildlife that feed upon them.   Whilst the effects of the extreme weather are obvious in our parks, gardens etc, the effects on rivers and streams are dramatic.   Chalk streams, in particular, have been affected; they are unique habitats.  The River Ver is a chalk stream in Hertfordshire.  The summer has seen large sections of its upper reaches reduced by several kilometres due to the hot weather (and water abstraction).  The effects in and around such streams may be felt for many years as the water levels fall so the habitats for fish, amphibians and invertebrates (such as dragonflies / mayflies) are reduced or lost.  Recolonisation of such drought impacted systems can be slow and prolonged.   An accessible and detailed paper on Beech trees and drought is available here : research gate.net [caption id="attachment_22186" align="alignright" width="300"] Mature Beech on Box Hill, Surrey.[/caption] [caption id="attachment_10575" align="alignleft" width="300"] Mature beech[/caption]

The UK has experienced some of the highest temperatures ever recorded in recent weeks, and in some parts of the country this has coincided with very low levels of rainfall.  It was the driest July on record for East Anglia, southeast and southern England, according to provisional statistics from the Met Office.  July was also the first time the UK exceeded temperatures of 40°C: on 19 July during an intense heatwave.   These conditions are not without their effects on wildlife.  Whilst warmth can accelerate plant growth and development, and also speed up insect life cycles, but the recent very high temperatures have significant effects, for example:  Drying of the soil As the soil dries, so earthworms burrow down deeper.  Insects, woodlice, spiders, etc avoid the surface of soil, hiding in litter so birds like song thrushes, robins and blackbirds struggle to find something to eat. Consequently, they are less likely to produce a second brood of chicks. This scarcity of invertebrates also affects ground feeding mammals, like hedgehogs (and badgers in more rural locations). Wetland areas dry out; for example grazing pasture that floods in winter - like the Ouse Washes.  This makes it difficult for birds to find food. Lack of water for plant growth Reduced rainfall and high rates of evaporation from the soil (and plants) mean that there is considerably less water available for plant growth.  The growth of leaves is reduced so that there is less material for caterpillars and other insects to eat.  With fewer leaves , there are also reduced surfaces for butterflies and other insects to lay eggs. High temperatures High temperatures and lack of water can affect many animals (including us). Rivers are running at very low levels and some have more or less disappeared.  DEFRA’s latest assessment of principal salmon rivers, such as the River Test shows that 74% of rivers in England are now ‘at risk’. The Environment Agency has noted the flow rate in the Waveney as 'exceptionally low', while other rivers in East Anglia like the Great Ouse  the  Yare, and the Little Ouse are described  as 'notably low'. The young of birds like swallows and swifts are at risk of fatal overheating (the young and old of various species are often more susceptible to heat stress).  Bumblebees cannot forage at high temperatures. Their bodies are covered with ‘hairy coats’ so they can fly when it is cool; but these become a burden in hot spells.High temperatures also shorten flowering time, and hence the availability of pollen and nectar for pollinators (bees, bumblebees, overflies, butterflies). Wild fires. [caption id="attachment_35352" align="aligncenter" width="650"] Woodland recovering from a fire[/caption] High temperatures increase the risk of wild fires, especially on moorland and heathland.  These fires can spread quickly and over wide areas. Young chicks (e.g. Dartford Warblers), eggs, snakes, lizards, small mammals, dragonflies and butterflies are lost.  Accumulated nutrients and stored carbon are lost from the ecosystems. The site of Springwatch Wild Ken Hill in coastal Norfolk suffered an intense fire during the recent hot spell.  The area is home to turtle doves, the grasshopper warbler and other rare birds.   It is hoped that most escaped but mammals, reptiles and amphibians, late-nesting and juvenile birds may not have fared well.   Grassland and woodland fires have also been reported at various sites across the country.  The UK is not alone in facing these problems, Spain, Italy, Portugal, Greece, France and Germany have all lost many thousands of hectares to wildfires. [caption id="attachment_38699" align="aligncenter" width="700"] what was once was grass .....[/caption]  

We are in the midst of a climate emergency: temperatures are rising, and in February 2022 the UN warned that more than 3 billion people are living in areas that are highly vulnerable to global warming, putting their lives at risk. Scientists suggest that rewilding could be one of the best climate solutions available to offset greenhouse gas emissions and to protect our lives and ecosystems. Rewilding involves restoring ecosystems and natural processes, and though at first it will require strict ecosystem management in order for it to be successful, the aim is that rewilding nature will allow it to then be able to ‘take care of itself’ and repair the damage made by humans. It’s estimated that restoring natural ecosystems could provide 37% of the greenhouse gas mitigation that’s needed for us to prevent the warming of the planet above 2 degrees celsius by 2030, so it should not be underestimated by national governments as a strategy to offset their emissions and restore the ecosystems of their countries. Ecosystem restoration Rewilding can restore ecosystems, allowing them to reach their full potential for fixing carbon, helping to offset greenhouse gas emissions through their own natural processes. Due to the fact that trees absorb carbon through the process of photosynthesis, it’s estimated that regenerating fully establishing forests will sequester 10 tonnes of CO2 per hectare from the atmosphere.  Meanwhile, restoring peatlands (which store more carbon than the world’s rainforests, but of which 80% have been damaged by draining, extracting, burning and overgrazing) will allow them to once again reach their full potential of sequestering carbon. Damaged peatlands in the UK release 23 million tonnes of carbon CO2 (or equivalent) per year, which is more than all of the UK’s oil refineries combined; restoring them will reduce this significant strain on the environment.   Restoring these ecosystems will also provide habitats for a large range of wildlife, which also play a crucial role in preventing climate change. The flora and fauna of an ecosystem are essential for its maintenance and conservation— they prevent catastrophic events like species’ extinction, flooding and wildfires. In fact, herbivores can have a massive effect on atmospheric carbon levels, so restoring their populations and allowing them to roam freely will mean they’re able to trample and compact soils and sediments, and increase the amount of carbon that’s absorbed and stored in plants, as well as impacting the natural growth of flora by redistributing seeds and their grazing. In the coming decades, as the effects of climate change worsen, reintroducing native plant and wildlife species will improve both the resiliency and carbon sequestering abilities of an area. It has also been shown that biodiverse environments are able to absorb more carbon, with each additional species introduced adding up to 6% in its total carbon stocks. Rewilding will benefit humans too of course, and not just in major ways (ie. protecting our livelihoods from the effects of climate change) but also by blurring the boundaries between the human and natural worlds, which will benefit our mental and physical health. There are also economic opportunities that can arise from rewilding, such as nature-based tourism.  Where is rewilding happening? There are many rewilding organisations across the world and in the UK, several of which have undertaken successful rewilding projects, restoring the carbon sequestering capabilities and increasing the numbers of species in different areas. Rewilding Europe have identified that after a decline in populations of several wildlife species, such as beavers, elks, whooper swans, and white-tailed eagles, they are finally increasing again. The Serengeti went from being a major source of carbon emissions to a sink after the wildebeest population were restored, and now sequesters between 1-8 million tons of carbon every year.  Rewilding has endless potential across the world, too: restoring forest elephants to their historic levels in the Congo basin could lead to it sequestering 85 million tons of carbon each year (the equivalent to France’s annual emissions) while rewilding and conserving the functional role of vertebrate and invertebrate species could supposedly magnify carbon uptake 1.5-12.5 times or more across terrestrial, freshwater and marine ecosystems.  The finance and politics of rewilding In the UK, Rewilding Britain has been calling upon the government to make a bolder ‘financial and political commitment to nature’s recovery,’ including developing policy for an ‘economy-wide carbon pricing mechanism linked to carbon emissions’ in order to raise money to fund rewilding projects. Though the Prime Minister has pledged to protect 30% of the UK’s land and sea by 2030 to allow it to recover and rewild, Rewilding Britain has suggested that there is not enough of an incentive for industries that contribute most to greenhouse gas emissions in the UK, such as the agricultural industry, and that the UK government have only attracted 2.5% of the funding that would be needed for the mitigation of greenhouse gases in this country. Instead, they propose a ‘polluter-pays’ approach whereby there is a mandatory price attributed to carbon emissions that the polluter must pay (they suggest £40 per tonne which would yield a maximum of £17.4 billion per year), which could then be reinvested into rewilding and conserving the natural environment. There would also be annual payments made to those who make efforts to offset carbon by restoring landscapes according to how much carbon (or equivalent) each landscape has the ability to sequester; woodlands would be £413 per hectare; salt marshes £322/ha; peat bogs and heathlands £292/ha; ponds and lakes £404/ha; offshore ecosystems £161/ha; and species-rich grasslands at £204/ha, with the payments being capped at 1,000 hectares per individual.  How to get involved in rewilding: Rewilding has the potential to make a significant contribution towards preventing the effects of climate change, but its full potential being reached relies on our international governments stepping up to the task of making sufficiently bold policy that incentivises farmers to restore landscapes, as well as businesses to pay the costs of their greenhouse gas emissions. The question is, how can the general public get involved in rewilding? There are lots of options available, whether that’s starting small by rewilding your garden by planting native wildflowers, to buying land with the intention of rewilding and conserving it, to volunteering for organisations such as Rewilding Europe, or writing to your local council to encourage them to leave roadside verges uncut. You might even consider providing funding for rewilding projects. Education about the rewilding benefits is also severely lacking, so raising awareness about how rewilding helps climate change is another way to get involved. No matter how we get involved, it will all contribute to the fight against climate change, so let’s get to it!

We know that insects (especially, bumblebees, bees, hover flies) are the world’s top pollinators, and we also know from many reports that many insect species are in decline.  Crops such as tomatoes, blueberries, peppers, cocoa, coffee, almonds and cherries are dependent on these pollinators.  Climate change, increasing temperatures and extreme weather events are affecting plants and animals across the world, and it seems that social insects, like bumblebees, are particularly impacted. Research with bumblebee colonies (at Stockholm University) has indicated that if the colonies are exposed to higher temperatures (than normal) then the workers in the colonies were smaller.  This decrease in body size could affect their foraging behaviour and the collection of pollen,  which would mean less food brought back to the colony and reduced pollination of plants. Studies in the United States looked at some 20,000 bees  (bumblebees, leafcutter bees, mason bees etc) along the Rocky Mountains, a region which is vulnerable to climate change.  It was found that the larger bees (particularly bumblebees) and those that built nests with combs were affected most by increases in temperature.  On the plus side, smaller (soil nesting) bees fared better.  Bumblebees would seem to have a lower heat tolerance.  The loss of bigger bees, which generally can fly and forage further may again mean reduction in long distance pollination (which promotes outbreeding in plant populations). One reason why hot or hotter weather affects bumblebees is that it influences the nectar that the bumblebees collect.  The balance of the various micro-organisms (bacteria and yeasts) in the nectar changes.  Whilst bumblebees are attracted to nectar with some microbes in it, a small change in temperature can speed up the metabolism / growth of the microbes so that they use up more of the sugar - with the result that it is less palatable / less nutritious for the bees.  Experiments conducted at the University of California have shown that bees did not ‘like’ the nectar rich in microbes, nor a sterile one - with no microbes at all. There seems to be a 'happy medium' in terms of the composition of the nectar. There seems to be a growing consensus that climate change, increasing temperatures and extreme events are pushing bumblebees (in particular) beyond their physiological limits. [caption id="attachment_38081" align="aligncenter" width="650"] Bumblebee visiting foxglove[/caption]

Certain woodland plants are found in the understory.  Plants like wood anemones, woodruff and lungwort bloom early in the year. These plants make use of a ‘window of opportunity’ when the light levels are good as the tree canopy has not developed, the leaves have not yet expanded. They use this ‘window of light ‘ to flower.   However, climate change is affecting many ecosystems - including woodlands.  With warmer temperatures, leaf buds tend to open earlier and the leaves begin to expand.  If the window for growth is reduced, how can the wood anemones and others cope ? [caption id="attachment_38093" align="aligncenter" width="700"] wood anemone[/caption] To investigate this question, scientists based the Universities of Tübingen and Frankfurt examined thousands of preserved herbarium specimens of early flowering plants, dating back over a hundred years.  The sheets not only hold specimens collected when they were flowering but also have  information on ‘when and where collected’.  Each sheet is a a moment in time from over a century ago.  Collectively, the 6000+ sheets allowed the scientists to establish historic flowering times of woodland plants over large areas of Europe. [caption id="attachment_38094" align="aligncenter" width="700"] Woodruff[/caption] The information extracted from the herbarium records revealed that plants like wild garlic and wood sorrel now bloom some six days early than at the beginning of the twentieth century.  For each 1oc rise in (Spring) temperature, their lowering has advanced by more than 3 days.  This means that they have gained time in the light - in an open canopy.  Whilst they may have gained time,  these early flowering plants are at greater risk of frosts.  It may also be that their pollinating agents may not be around - unless they too have brought forward their development / life cycle. There is some evidence that such changes are taking place.  Recent work at Wytham Wood (outside Oxford) has shown that blue tits have moved forward their egg laying to 'match' the development of the oak canopy, and the appearance of caterpillars (on which the young are fed).  Essentially, the timing of the food chain has changed..  Hopefully, such changes will occur in different ecosystems across the country.