Investigating interactions between terrestrial biosphere and climate Recent research carried out with support from the Community's specific RTD programme in the field of Environment and Climate suggests that an increase in greenhouse gases related to man's activity may actually have a positive effect on plant production but disturbs the natural... Recent research carried out with support from the Community's specific RTD programme in the field of Environment and Climate suggests that an increase in greenhouse gases related to man's activity may actually have a positive effect on plant production but disturbs the natural carbon balance. The impact on the climate system and the response of the terrestrial biosphere are not well known. This highlights the need for further research to understand interaction and feedback mechanism between the terrestrial biosphere and the physical climate system. The aim of the EU-funded ESCOBA projects (European Study of Carbon in the Ocean, Biosphere and Atmosphere) is to describe, model and predict interactions between the earth's carbon reserves and the climate. To meet these objectives, coupled models of the ocean, atmosphere and the terrestrial biosphere have been developed. Within the ESCOBA Biosphere project such models are used to study the human influences on the carbon cycle for different time scales and its impact on ecosystems, with an emphasis on temperate and boreal forests. The improved models account for biogeochemical processes such as photosynthesis, carbon fixation and litter formation. Much effort is devoted to testing the models, using for example measurements of atmospheric CO2 concentration and inter-annual variabilities. Earlier results indicated a net negative impact on ecosystem productivity with rising temperature and reduced precipitation associated with the increase in greenhouse gases. However, by including the direct effect of CO2 levels on photosynthesis, the models developed by ESCOBA, along with those of other European teams, have concluded that the effect on plant production may, in fact, be positive.
