The Jena Diversity (JeDi) Model: A New Functional Diversity Approach To Modelling The Terrestrial Biosphere
Abstract
Current state-of-the-art terrestrial biosphere models usually do not account for biodiversity, representing the diversity of vegetation form and functioning using only a small number of plant functional types. In the Jena Diversity (JeDi) model, we introduce a new approach, based not on plant functional types, but on plant ecophysiological trade-offs. The JeDi model tests a large number of plant growth strategies. Each growth strategy is simulated using a set of randomly generated parameter values, which characterize its functioning in terms of carbon allocation, ecophysiology, and phenology, which are then linked to the growing conditions at the land surface. The model is constructed in such a way that these parameters inherently lead to ecophysiological trade-offs, which determine whether a growth strategy is able to survive and reproduce under the prevalent climatic conditions. Kleidon and Mooney (2000) demonstrated that this approach is capable of reproducing the geographic distribution of species richness. More recently, we have shown that JeDi is also able to reproduce the relative abundances of species within communities and the large-scale gradient of ecosystem evenness (Kleidon et al. 2009), as well as the global patterns of biomes (Reu et al., in prep) and biogeochemical fluxes and associated land surface properties (Pavlick et al., in prep). The Jena Diversity model explains how climate constrains the geographic patterns of plant biodiversity and biogeography and also allows us to understand the emergent effects of functional diversity on land surface functioning in the Earth system. Here we present some results from the JeDi model, wherein we vary the modelled functional diversity to quantify its impact on terrestrial biogeochemical fluxes. A richer representation of functional diversity leads to enhanced predictability of the biospheric response to environmental variability. This approach sets the foundation for future applications,in which the simulated vegetation response to global change has a greater ability to adapt through changes in ecosystem composition, having potentially wide-ranging implications for biosphere-atmosphere interactions under global change.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFM.B21C..04P
- Keywords:
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- 0410 BIOGEOSCIENCES / Biodiversity;
- 0414 BIOGEOSCIENCES / Biogeochemical cycles;
- processes;
- and modeling;
- 0426 BIOGEOSCIENCES / Biosphere/atmosphere interactions;
- 1622 GLOBAL CHANGE / Earth system modeling