A thousand years ago, significant areas of the country were devoted to wood pasture, that was grazed by livestock.  As time passed, much of this became royal hunting forest - a mixture of woodland, coppice, open land and farms.  As the woodlands were managed (through traditional techniques such as coppicing and pollarding), many of the trees were able to grow to maturity.  They became veteran trees.  Trees such as beech reach maturity after some 200 years, oaks take 400 years and yew 900+.   Such veteran trees can be seen in areas like the Savernake (south of Marlborough) and Sherwood Forests. Saverrnake has veterans like the Big Belly Oak, and Sherwood has the Major Oak.  Sadly, since the nineteenth century many veteran trees and ancient woodlands have been lost due to the expansion of agriculture, housing development and road & rail creation.  Veterans have also been lost from hedgerows, many of which were grubbed out to enlarge fields to allow for increasing mechanisation. As oaks and beeches age so they change, they expand, trunks hollow, cracks and holes appear, heart rot develops and dead wood appears.  Each tree offers a myriad of micro-habitats.  Bracket fungi feed on the dead heart wood, as do stag beetle larvae.   Mosses and lichens live on the bark, attached to crevices that channel the rain down the trunk, bats, woodpeckers and nuthatches inhabit holes. Other birds (like redstarts) nest in the branches and twigs.  The decaying leaf litter beneath the tree offers sustenance to a variety of beetles, and fungi (e.g. oakbug milkcap).  English oaks are associated with more than two thousand species, and more than two hundred are directly dependent on the trees. The loss of so many veteran trees has resulted in an international project to determine if these trees can be ‘replaced’.  It involves a technique termed veteranisation. Younger trees are damaged in order to start the process of decay and ‘ageing’.  The process may include Creating woodpecker-like holes Creating nest boxes for birds / bats Breaking branches Damaging the bark / trunk - to simulate deer / animal damage Inoculation with fungi It is being trialed at some 20 different sites in Norway, Sweden and England.  The project started in 2012 and will run for some 25 years.  It is hoped that such ‘techniques’ could be used to accelerate the formation of veteran trees status with its associated biodiversity. Thanks to Angus for tree jpgs. For further information : https://naturebftb.co.uk/wp-content/uploads/2021/09/Introduction-to-Ancients-of-the-Future-Jamie-Robins.pdf https://www.gov.uk/countryside-stewardship-grants/creation-of-dead-wood-habitat-on-trees-te13 https://www.woodlandtrust.org.uk/media/1798/wood-wise-ancient-trees.pdf  (opens PDF)

Wetlands. In the past, many areas of wetlands have been drained and ‘dried out’.  Now it is recognised that this is counter-productive in terms of carbon storage / sequestration and biodiversity, so there are now measures to restore wetlands. The hope has been that restoration of wetlands will do much to restore the variety of plants and animals (and help carbon storage).  However, research by the University of Copenhagen suggests that such projects might be ‘struggling’. The study examined ten wetlands (near the River Odense) that were restored between 2001 and 2011.  The restoration involved the removal of drains and ditches, and allowed streams to meander again instead of flowing in ‘straight channels’.  The aim of the project was primarily to reduce the leaching of nitrogen and phosphorus from adjacent farmlands, and hope to see greater diversity of plants (e.g. marsh orchids, globeflower, tussock-sedge and ragged-robin).   The ‘restored’ wetlands were botanically poor (whether restored in 2001 or 2011), they had only a quarter of the plant species compared to natural wetlands.  This may be due to  the continued input of nutrients (from agriculture), which encourages species that are ‘nutrient hungry’ at the expense of others. the ‘difficulty’ of wetland species to disperse from one area to another. It may be that future restoration programs will need to include planting / seeding of additional wetland species. It has been suggested  that it could take the best part of a hundred years for the restored wetlands to resemble natural wetlands. Redwoods and relatives. Previous posts have talked about the special features of the giant redwoods (their height, age etc).  Over the last 150 years, they have ben subject to the pressures of commercial logging, clear felling and more recently high intensity fires.  Indeed, the fires have been of such an intensity that seed banks in the soil have been destroyed. Now they have been subject to genomic analysis, that is their DNA has been analysed and sequenced.  The first conifer genome to be sequenced was that of Norway Spruce, then that of loblolly pine.  These suggested that conifer genomes are large (3 to 10 times larger than the human genome), with repetitive sequences.  Coast Redwoods are hexaploid, that is, they ave six copies of each chromosome (we are diploid, that is, have only two copies of each chromosome).   The DNA of a coast redwood has  27 billion base pairs of DNA, the giant sequoia has 8 billion; by contrast we have circa 3 billion.   It is hoped that the Redwood Genome project will see the restoration of areas of coast redwood and giant sequoia that have been lost over the years. The genomic analysis will help inform and guide management strategies, ensuring genetic diversity in the newly planted tree seedlings. Such a strategy will (hopefully) enable newly planted areas to survive and thrive — in the Anthropocene. More on chromosomes Just as it has recently been shown that Coast redwoods are polyploids (i.e. have extra sets of chromosomes), so recent research in the Czech Republic has shown that the common nettle [Urtica dioica] has different ecological ‘preferences’ depending on its chromosomal status.  Nettles can be diploid (2n = 26) or tetraploid (2n = 52).  The tetraploid nettles seemingly have a broader ecological tolerance and a wide geographical distribution, whilst the diploid nettles occur in a narrower range of ecological conditions. Details of this research can be accessed here (note link opens a PDF) and Plants for a future has lots of information on nettles.    

We know that forests are important to all life on the planet.  They have often been referred to as the ‘lungs of the earth’, a reference to the fact that they produce vast quantities of oxygen - which is essential for respiration for so many forms of life.  They also take up carbon dioxide and ‘fix’ it into complex organic molecules - from starches, to cellulose and lignin.  Thus, the carbon is locked away for months, years or even millennia.  The equatorial forests of Brazil and Sumatra are species rich, incredibly diverse, but deforestation and the expansion of agriculture are threats to many biodiverse, forested areas across the world. As so many forests and woodlands have been felled, there is now a movement to plant millions and millions of trees (across the world) in an attempt to mitigate climate change and in the UK to increase our percentage tree cover from a pretty low base.  Sadly, twentieth century forestry in the U.K was largely based on monocultures (for timber production). The trees planted were large stands or plantations of conifers - using Scots Pine, Larch and Spruce. These plantations not only lacked biodiversity, but were / are susceptible to wide scale pest infestation and extreme weather events.   Woodlands and forests that have a diverse range of tree species are not only healthier but show greater growth and carbon fixation. They are more resilient.  The diversity of trees ensures the each species accesses slightly different resources from the environment  - from soil minerals, water and light.  Diversity means that trees of the same species are less likely to be clustered together so pest and pathogen outbreaks are less common or less severe.  One area that has undergone an extensive and diverse planting regime is Norbury Park Estate (near Stafford).  Since 2009, over 100 different tree species have been planted, and the woodlands can now produce 1500 tonnes of new wood each year, and harvest 5000 tonnes of carbon dioxide from the air.  Not only can diverse woodlands / forests fix carbon, supply harvestable timber but they also offer areas for rest and relaxation. Whilst it is not possible to plant an 'instant' forest or woodland, it is possible to plant a range of tree and shrub species that will in time grow and mature to form a diverse and species-rich area.  As Charles Darwin said many years ago “more living beings can be supported on the same area the more they diverge in structure, habits, and constitution” [On the Origin of Species by means of Natural Selection, 1859] Managing woodlands for wildlife - see here.   N.B.  Opens a PDF.    

Compared to some of our European neighbours, it seems that our percentage woodland and forest cover is quite low at 13%; as was recently discussed on the BBC "More or less" programme.  Only Denmark and the Netherlands have similar low levels of cover.  Finland, on the other hand, has almost three quarters of its surface area covered with trees. After the end of the last ice age, trees gradually recolonised the exposed landscape so that vast swathes of the U.K. were covered with woodland/forest - the wildwood. It might be thought that our current low figure is due to increased urbanisation, road/motorway construction etc. In fact, the tree cover is remarkably similar to that at the end of the first millennium CE. More trees were ‘lost’ in succeeding centuries with the expansion of farming, and trees were harvested for boat building and house construction.   The Mary Rose was built using oak and elm. It was the first big ship of the Tudor naval fleet.  It has been estimated that over 600 trees were needed for its construction; that is equivalent to about 16 hectares of forest/woodland. Wood was also used to produce charcoal, which was used to smelt metals, particularly iron.  The history of charcoal burners in the New Forest is well documented. Many woodlands / forests were the preserve of the landed gentry and the aristocracy and reserved for deer hunting.  Anyone caught killing deer or boar from such woodlands could suffer terrible punishments but would more likely be fined.. Woodland and forest continued to be depleted so that by the end of the seventeenth century, the percentage cover had fallen to 8%. At the beginning of the twentieth century, the figure stood at a pitiful 5.2%.  The Asquith administration in 1916 established a committee to report on the country’s woodlands and timber supplies.  This lead to the setting up of the Forestry Commission which was not just concerned with established ‘strategic reserves of timber’ but also trying to create viable communities in marginal areas. Through its efforts over the succeeding decades, the U.K’s area of woodland and forest has increased significantly - though the Forestry Commission’s heavy use of coniferous species (particularly in the 60’s and 70’s) has been criticised.  Coniferous woodland / plantations do not support such a wide range of plant and animal life as deciduous woodland.  However, their current emphasis on diversity (and recreational use) favours a much wider range of species, including broadleaved/deciduous trees and the development of a richer ground flora.

The Flow Country is a large area of peatland and wetland in the north of Scotland (Caithness and Sutherland). It is one of the largest expanses of blanket bog in Europe. It is characterised by deep layers of peat and bog pools.   Wetlands, like this,  are important  as They offer a significant wildlife habitat and They act as mitigating agents in terms of climate change (locking up large amounts of carbon). However, some four decades ago, parts of the Flow Country were planted with conifers,  there were financial incentives to  this planting; namely : grants were available towards the costs of planting other costs were tax deductible so investors spent only 20p for every £1 of capital invested prospectively, income from timber was to be virtually untaxed. This ‘forestation’ of wetlands is now generally regarded as a mistake, not only damaging a unique environment but leading to increased carbon emissions.  Now it seems possible that similar mistakes may be made again.    Read more...

Much of England experienced a series of ‘tropical nights’ last summer, when night time temperatures were 20oC or above.  These tropical nights were associated with the heat wave that affected most of south east England.  Central London experienced its longest stretch of extreme daytime temperatures since the 1960’s -  temperatures of 30+oC were recorded on six consecutive days.  A number of experts have said that such heatwaves and associated tropical nights are likely to become more common as a consequence of climate change.   We were not alone in experiencing high temperatures by day and night, much of western Europe  sweltered in the heat this August. The problem was most marked in urban areas and large cities.  Some three-quarters of the population of Europe now live in urban areas. Extreme heat affects our health causing general discomfort, malaise, respiratory problems, headaches, heat stroke, heat cramps and heat-related mortality.  Read more...

Sadly, the number and range of various species in the U.K. is decreasing, biodiversity is falling. Our wildlife-rich areas are actually separated and fragmented, by tracts of intensively-farmed land, by motorways and roads,  and the ever increasing spread of urban areas. The dispersion and isolation of wildlife areas makes it difficult for both plant and animal species to move.  The ability to move around is ever more important as a result of climate change.   Rainfall patterns and average temperatures in different regions are changing, extreme weather events are more common.  For a species to stay in its  ‘comfort zone’, it may need to move ‘northwards’ as climate change continues.    According to a report released by Rewilding Britain, the speed at which species need to migrate in order to stay in their ‘comfort zone’ is approximately some 5km / year Read more...

The 1950’s and 60’s saw the destruction of many hedgerows, particularly in farming areas like East Anglia.  The logic behind this was to increase field size and allow ease of access of machinery, like large combine harvesters that were coming available at that time.  The loss of the hedgerows and their associated wildlife is quite well documented, but the loss of ponds that occurred in and around this time has not attracted much attention.   Many hundred of ponds were filled in (often using the debris and material from the destruction of the hedgerows), giving a few more metres of arable land.  The position of these ponds can sometimes be found on old ordnance survey maps.  Ponds across Norfolk have suffered from neglect or have been filled in,  over the last 50 -70 years.  Many are located on farmland and their origins may extend back centuries when they were created as marl or clay pits, sometimes for the watering of livestock; they are sometimes referred to as the lost or 'ghost' ponds..  Some were formed in depressions (pingos) left after the last age. Read more...