Trees are remarkably resilient.  In various forms they have been arounds for millions of years.  They have survived asteroid impact (66 million years ago), and a series of successive ice ages.  However, in more recent times they have faced a new challenge, the relentless march of humankind. Early societies felled trees for timber for dwellings, boats*, wood for fire, making tools, as part of ‘flash and burn’ agriculture to create a ‘swidden’ to grow food.  The material felled to create a swidden was allowed to dry and then burnt, the ash released mineral nutrients into the soil for the crops.  As more complex civilisations / societies evolved, there were attempts to restore degraded forests / bare land, and  to protect forests.  The Zhou (Chou) dynasty established a ‘forestry service’ over two thousand years ago, and in India the emperor Ashoka (268 -232 BCE) ordered wide scale reforestation.  Much later in the Middles Ages there were efforts to restore degraded areas, for example, around Nuremberg in the C12th.  Most of these early efforts were concerned with increasing timber production or the mitigation of natural disasters.  In the last two centuries, significant areas of natural forest and woodland have been lost, increasing the risk of soil erosion, flooding and disease (as animals are displaced). In the last century, the percentage cover by forest / woodland in some countries (for example, the UK) was low so vast areas were planted with a single species. Fast growing species (conifers such as pines, spruce and larch) were often grown on what was regarded as marginal land, creating plantations.   In some parts of the Mediterranean, Eucalyptus was planted.  These were species that could cope with the challenging nature of the soil and / or the  topography.   Many of the European initiatives met with some success in terms of timber production and / or the stabilisation of degraded areas (for example, reducing erosion).  Such schemes also created jobs, contributing to the local economy.  But when grassland or heathland were used to create single species plantations, this was often accompanied by a loss in biodiversity. In places, the introduction of non-native species has been challenging as they have become invasive, for example, black cherry. The success of any scheme is dependent on Sound planting techniques and aftercare Selection of the right species for the area The co-operation / involvement of local peoples. Mass planting of a single species can also contribute to the rapid spread of disease / pests (e.g.bark beetles, pine procesionary moth).  Vast swathes of coniferous forest were affected by acid rain (associated with sulphur dioxide from the burning of fossil fuels) in the last century.  This was termed Waldsterben [Wald=forest + sterben=to die].   Problems such as these, coupled with increasing environmental awareness contributed to a rethink of the aims and objectives of forest management / renewal / restoration. However, there were examples where ecological recovery was good, for example, some spruce and black pine ‘monocultures’ were diversified through the planting of a understorey of broadleaved trees, as in Slovenia. In recent times, timber production, control of erosion and reduction of disaster risk remain relevant still, but the importance of biodiversity, resilience and ecosystem services are now uppermost.  There is a move from ‘quantity to quality’ of forest and woodland.  In many countries, a growing interest in recreation and tourism (recognising the importance of green space for mental and physical well being), coupled with growing environmental concerns and recognition of climate change has emerged.   Forest and woodlands across the world, from the boreal regions to the Equator are under threat.  Many have been lost or badly degraded, and are in desperate need of restoration.  Forests are no longer regarded as sources of timber, but are important providers of ecosystem services, such as the mitigation of flooding. So, in more recent times they have been efforts to restore and repair forests and woodlands.  Homogenous and dense plantations / forests in boreal regions had clearings created to allow light demanding species to establish.  Limitations have been placed on clear cutting, and the use of fencing, tree protectors have [caption id="attachment_41889" align="alignleft" width="300"] squirrel[/caption] helped to reduce browsing pressure (by deer / squirrels etc).  One means of promoting biodiversity is ensuring that the woodland / forests offer deadwood.  This provides a ‘home’ to species as varied as woodpeckers to saproxylic beetles. These beetles help break down wood so that it can be further broken down by fungi and bacteria, returning nutrients to the soil. Tree girdling was a technique used in Finland to create deadwood, it severs the conducting tissue (phloem) so that the supply of sugars is interrupted.  Thought is now given to the selection and introduction of tree species that are adapted and resilient to anticipated climate change impacts.   Though countries have adopted a variety of techniques in recent times, the extent of forest and woodland restoration has been largely limited by the funding available.  Restoration does not come cheap, funding over significant period of time is needed, and time itself for the effects of  the measures to become apparent. For detailed information on forest restoration see - https://link.springer.com/article/10.1007/s40725-024-00235-3 Intereesting facts : Henry V111’s flag ship, the Mary Rose , was built using oak and elm. It was the first big ship of the Tudor naval fleet and it is estimated that over 600 trees were needed for its construction,. That is equivalent to about 16 hectares of forest / woodland.  And Cver 370 species are supported in the territories of the Karen swidden farmers in northern Thailand.  

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"  

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.