There is a story I believe everyone needs to hear about woodlands, in particular ancient woodlands. Earth’s forests are silent victims of the effects of human activity – of the tree diseases, the introduction of invasive species and the extremes of weather which are cumulatively, slowly, and increasingly destroying their ability to survive and thrive in the way they have for so many centuries.
I want to describe and show the devastating effects we humans are having on a resource that is necessary to sustain life. We know that trees provide almost a third of the oxygen in our air, while sequestering massive amounts of CO2. If Yorkshire is God’s own county, he or she can’t be very pleased with what we’re doing to a key component of what we need to live.
Invasive species
Wikipedia tells us we have to thank a Victorian, John Forbes Royle for the introduction of Himalayan balsam to the UK. It’s a pretty plant. However, it spreads quickly and smothers out native plants.
Balsam is difficult to control because if only one specimen is missed whilst trying to eradicate it, the area will not be clear the following year – every plant produces many seeds which when ripe pop and disperse widely. They are easily transported along watercourses. If they are cut or hand pulled out of the ground there will soon be another wave emerging to replace them. The area may look clear, but it won’t be.
Damn you John Forbes Royle – ignorance is no excuse!
Himalayan balsam is just one of many invasive species – like Japanese knotweed, Rhodendrum ponticum, giant hogweed – that have been brought into this country and now wreak havoc on our native flora and fauna.
Non-native trees for profit
Sycamore trees were introduced to the British Isles a long time ago, around 1500. They are fast growing hardwoods; the timber has many uses and is valuable. However, in high densities it blocks sunlight from the woodland floor and prevents native plants from thriving. Again, one tree produces many seeds and it can become a dominant species unless carefully managed.
Norway spruce (the Christmas tree) is frequently planted at high density in commercial plantations. When they get to a specific height daylight is almost totally excluded and the ground is a carpet of needles where nothing grows. The tree is a valued crop, harvested at a certain height for those who like a real tree at Christmas, but offers minimal benefit to wildlife. Similar problems exist with Sitka spruce plantations and Lodgepole pine.
After the Second World War vast swathes of land were planted with monoculture pine trees, often planted in the wrong place simply because they are fast growing and reach maturity in less time than native hardwoods. A policy that thankfully is no longer supported.
Tree diseases we’ve let in
According to the organisation Forest Research, the more aggressive form of Dutch Elm disease was “accidentally introduced into Britain in the 1960s”. Goodbye, to around 25m of our beautiful native elm trees.
When an elm dies, its roots send up suckers which grow into new small trees, but at a certain height (no more than 12m), the beetle attacks again and they die. The species is trapped in this shortened cycle of life. Some hope is now offered by the breeding of resistant elm species, but it’s early days.
The Oak Processionary Moth is another “accidentally introduced” pest which can strip a tree of its leaves and against which the UK is waging a constant battle.
UK’s failed biosecurity systems
Chalara ash dieback was first confirmed in the UK in February 2012, in a consignment of ash plants sent from the Netherlands to a nursery in Buckinghamshire, England. This disease has now spread through much of the UK and is having a devastating impact. There is some encouraging news about resistant strains, but again it’s too soon to feel reassured.
The origin of so many of these diseases lies with a failure of UK biosecurity systems.
What an abysmal record we have at importing tree diseases that then go on to destroy the very plants that absorb carbon and give us oxygen.
Introduced species
Grey squirrels were introduced in the 1800s primarily as an ‘ornamental’ species for parklands and private estates. Either through their own hardiness or thanks to help from humans they spread widely across the UK – they cause damage to trees and out-compete and spread disease to native red squirrels.
Deer have a significant detrimental effect on a woodland’s natural ability to regenerate, and there are now several species of introduced deer, including muntjac, sika and Chinese water deer that have added to the problems.
UK’s chaotic climate change
As if all this is not enough for woodland to contend with, our climate is changing in chaotic ways. It’s not that winters are wetter, it’s that the intensity of the rain is such, falling on to very dry ground, that it results in flooding. Standing water in woodland loosens the ground and makes trees more liable to being blown over in a strong wind.
Conversely, in summer, long periods of dry weather cause stress to trees, as the ground dries out deep into the subsoil. At the same time, it affects the tree directly, making the timber so brittle that the branches or even the trunk will snap more easily.
Government funding to manage woodland
Government grants are now available for a variety of woodland work. However, you have to be pretty expert in knowing how to apply, in a format that will secure the grant. This has spawned an army of consultants whose fee for the services is of course more than the grant is worth. A perfect recipe for inaction.
The sickening thing of course, is that these problems are closely linked to ineffective biosecurity controls at the UK border. Yet even woodland owners who are able to secure a grant for remedial work still have to pay the lion’s share, as any grant pays a fraction of what is needed. The woodland owner meets the bulk of the cost to solve a problem not of their making, as well as providing copious records to prove the work was done.
Extreme weather
Intense rainfall weakens tree roots. Note the brackish water which is silt run off from nearby agricultural land, draining that land of vital nutrients
The roots of this oak tree will have been snapped, which may cause it to die slowly over a number of years
Once versatile oak trees – even a mild wind can snap either the trunk or a branch at any time of the year
In summer, intense drought bakes the earth dry
Dutch elm disease
An oak tree lost due to a combination of saturated ground and wind
Fallen mature ash tree as a result of ash dieback
It’s only a matter of time before this once fine specimen tree falls thanks to ash dieback
Unusually high winds in summer months snap stressed and weakened tree branch from trunk
The photos I’ve included here show what is going on inside an area of ancient woodland and provide a record of what has happened over the last 10 years.
We depend on our woodlands
One really has to wonder what is in store for us in the years ahead. These falling trees may well be laying down the coalfields for future millennia, but well before then will those in power have received a rude awakening to the fact that they acted too little too late?
We criticise other nations for denuding the planet of trees, yet we are part of the same problem. We are ignoring what’s happening to the woodlands in our own backyard, or paying peanuts in the form of grants that barely begin to address the effects of climate change. We all need to wake up – because life without our woodlands would be almost untenable.
