Oene H ,
Berendse F ,
Alkemade FRM ,
Bakkenes M ,
Ihle F ,
Kovel CGF de
170 p
in Dutch
1999
Toon Nederlands
English Abstract The aim of this project was to analyse the effects of
climatic change on plant species diversity and ecosystem functioning. The
direct effects of climatic change on plant species diversity were analysed
using a species-based probabilistic model (EUROMOVE) that relates the
probability of occurrence of ca. 1400 European plant species to climatic
variables like the mean temperature of the coldest month, the effective
temperature sum, the annual precipitation, the annual potential and actual
evapotranspiration, the length of the growing season and the mean growing
season temperature. The indirect effects of raised CO2 levels and increased
temperatures on ecosystem functioning, and the consequences of these
indirect effects for plant diversity, were analysed by combining a
mechanistic simulation model (NUCOM) with regression models. NUCOM predicts
the effects of environmental changes on dominant plant species composition
and ecosystem variables. The predicted ecosystem variables are linked to
plant species diversity of subordinate species by regression models using
Ellenberg indices for N availability, soil acidity, soil moisture and light
intensity. The consequences of climatic change scenarios (IPCC Baseline A,
IPCC Stabilisation 450) and N deposition scenarios (reduced, constant) were
analysed using these two approaches for Europe (EUROMOVE) and part of the
Netherlands (NUCOM). The results showed that the direct effects of climatic
change may have a large impact on plant species diversity and distribution.
The indirect effects of climatic change on plant diversity appeared minor
but effects of changes in soil moisture are not included. Other
environmental changes like eutrophication and human impact have a large
effect on ecosystem variables and plant species diversity. Reductions in
nitrogen emission have a positive effect but take time to become
apparent.