Climate change puts trees 'under stress'
7 December 2009
The forests of Scotland could be increasingly at risk as climate change begins to bite and drought-ridden summers put trees under stress, according to researchers from the Forestry Commission.
The Scottish government has already pinpointed Scotland's forests as a key resource in tackling climate change, both through their ability to lock up carbon and also as a source of renewable energy. However, many of Scotland's commonest forest trees, such as Sitka spruce, Norway spruce, larch and beech, are particularly badly affected by low rainfall, developing cracks and fissures and falling prey to fungal infections as they become stressed by drought.
A survey of Scottish forests by Dr Sarah Green and Duncan Ray, of the Commission's Forest Research arm, combined data on soil type and quality with past and predicted future weather patterns to identify the forest sites in Scotland most at risk. Almost one in three forests they assessed in the east of Scotland were found to be at moderate or high risk of drought damage.
Evidence of suspected drought damage has already been found on many trees in Scotland in recent years: in some sites, up to one in five Sitka spruce died following the 2003 drought, while fungal diseases such as Armillaria (honey fungus) and bluestain fungi in larch have been seen to increase after spells of dry weather.
Drought-susceptible tree species will still have a place in the wetter climate of the west coast of Scotland, and on soils with a greater capacity to hold water, says Dr Green. But, she adds, on freely draining, sandy soils in the more drought-prone eastern forests, planners should now consider planting more drought-resistant species such as Scots pine or Douglas fir to help the forests adapt.
Further information on the research