On Monday America’s oldest oak tree – located in a New Jersey Presbyterian churchyard – was felled, bringing an end to a life that had spanned 600 years. Yes, it hadn’t reached the age of the Big Belly Oak in Wiltshire’s Royal Hunting Forest, or Nottinghamshire’s The Major Oak – both aged at around 1,000 years old – but it nevertheless still held a deep-rooted connection with its local community. This was a tree with historical significance, a tree which an entire town was built around, a tree which President George Washington once sat and picnicked beneath (the contents of the picnic are unknown, although unconfirmed reports suggest that ham sandwiches, Jaffa cakes and a packet of Wotsits were consumed). However, like with all living things, nothing lasts forever. With age, trees can become susceptible to rot, to environmental stresses and to biotic agents – such as insects and pathogens – all which can, ultimately, result in death.
A little morbid, right? Perhaps, but with death comes life. When a mature tree dies in a forest it allows other life to flourish. As the wood rots, it becomes host to a wide array of organisms; species of lichen, fungi, invertebrates and birds are dependent upon the microhabitats that arise from a tree’s demise. It doesn’t stop here though, death can also aid other plant species within an ecosystem – particularly by the recycling of nutrients. The nitrogen which was once stored within the wood, a vital component for plant growth, is slowly released into the soil as the tree decays. Environmental relationships should be marvelled at; a compound that is crucial to life becomes available as a direct result of death. Finally, once the standing dead tree falls it creates holes within the forest’s canopy, allowing the necessary sunlight to the ground for other species to establish themselves in the trees place.
The environmental benefits following the loss of a tree hold great value, however that tree – which represents an important resource itself – has still been lost. An importance that should not be understated. In addition to their role in sequestering carbon, trees also play a huge role in our everyday lives. The timber structures that keep your home standing, the furniture within it, or even the very paper that this article is printed upon; all products that stem from the humble tree. So, let’s not lose them.
Knowing the exact number of trees on Earth is an important, yet nigh on impossible task to undertake. This is all set to change in 2021; Biomass – an aptly named satellite produced by the European Space Agency – will be launched into Earth’s orbit to monitor the world’s forests. Using synthetic aperture radar, which can penetrate a forest’s canopy, Biomass will monitor both how much land is covered by forests and the amount of wood contained within them. So, what about the UK’s forest resource? What condition will our forest be in by 2021?
Since the end of the Second World War – when the UK’s forest resource was at its lowest in human history – our forest land coverage has increased from a mere 5% to a much healthier 12%. These increases have started to stall though, with the UK’s annual tree planting figures gradually falling during the last decade. This came to a head last year when just 700 hectares of trees were planted in England and Wales, much less than the Government’s targeted 2000ha, prompting concerns that the UK’s forest resources are on the cusp of suffering deforestation. Considering the potential role of trees in combating climate change by sequestering carbon, we should be adding to our forest stocks instead of taking away from them. Trees die, so let’s plant more. Lots more.
Dougie Phillips
Science editor
(Image courtesy of gottakeepmoving.com)