UK forest monitoring system

 

Managing a unique intensive forest monitoring network around Britain

News from Forest Research: November 2007

Progressive change is easy to miss and only when we step back and compare the past with the present can we see just how much change has been happening over time.

Since 1994, Forest Research has been managing a unique intensive forest monitoring network around Britain that provides continuous, detailed information on the condition of forests and their interaction with the environment at both local and regional scales.

Ground-level ozone pollution, ‘acid rain’, climate change, invasive pests and diseases can all affect the structure and composition of forest ecosystems. Our ability to predict the scale and pace of change provoked by these environmental disturbances relies on a sound understanding of forest ecosystem resilience across a wide range of geological and soil environments. Forest Research’s network of monitored forest plots is helping to improve our understanding of cause-effect relationships and our ability to forecast change.

The network is made up of 20 permanent forest plots positioned across a broad range of pollution environments and climatic conditions. Each plot is continually assessed for:

• Local air quality
• Meteorology
• Atmospheric deposition
• Soil condition
• Tree growth
• Crown density
• Litterfall
• Phenology
• Ground vegetation.

Soil fungal communities are also occasionally monitored as part of related research work.

This network forms only a small part of a much larger European-wide forest monitoring network across which all measurements are standardised. It provides us with a means to gauge and understand reasons for changes in forest condition and also alerts us to the need to take rapid preventative action where problems emerge. Climate change in particular is pushing us all to consider the environment from this wider, cross-boundary perspective.

Among the subtle changes picked up by the British strand of the monitoring network, is a notable deterioration in tree crown densities of Scots pine since 1995 in the historically polluted Pennines. Although acid deposition measured in rainfall has fallen significantly at the monitoring site there, comparative improvement of soils at this site is slow, with levels of acidity and aluminium in the soil recovering at a gradual rate through time. This suggests a long time-lag in the recovery of certain forest soils to air pollution. On the other hand, the network has laid to rest bigger worries about the scale of ‘acid rain’ damage to forests. Nearly two decades ago, press headlines suggested alarming scenarios of catastrophic, wide-scale forest damage caused by air pollution. Tree growth and crown condition assessments show that forest condition has deteriorated far less dramatically on a European scale than was previously feared. Analysing the chemicals in rainfall has shown a reduction in sulphur pollution over the past 10 years attributable to the success of clean air emission control policies.

Looking to the future, what else is on the horizon to alter the stability of forests and their ecosystem?  Certainly, the local effects of excess nitrogen (as ammonia) and ground level ozone pollution are now emerging as potential future causes for concern, alongside the direct and indirect effects of climate change on the forests and woods of Britain.

More details are included in the recent Forestry Commission Information Note: Ten Years of Intensive Forest Monitoring:

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Alternatively contact Nadia Barsoum.