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Watershed Planning within a Quantitative Scenario Analysis Framework
Published on: July 24, 2016
Assessing uncertainties in a second-generation dynamic vegetation model caused by ecological scale limitations.
Rosie Fisher1, Nate McDowell, Drew Purves
1Earth and Environmental Science Division, Los Alamos National Laboratory, Los Alamos, NM, USA. rosieafisher@gmail.com
The New Phytologist
|July 13, 2010
Summary
Demographic processes like seed dispersal and mortality significantly impact vegetation model predictions. Understanding these dynamics is crucial for accurate ecosystem and climate change response modeling.
Area of Science:
- Ecology
- Climate Science
- Computational Biology
Background:
- Second-generation Dynamic Global Vegetation Models (DGVMs) incorporate disturbance, light competition, and succession.
- These models often lack explicit representation of demographic processes at finer spatial scales.
Purpose of the Study:
- To investigate how demographic processes influence predicted community structure in DGVMs.
- To assess the impact of these processes on ecosystem responses to climate change scenarios.
Main Methods:
- A modified second-generation DGVM was used with a simulated Amazon rainforest ecosystem.
- Five key demographic parameters (seed advection, seed mixing, sapling survival, competitive exclusion, plant mortality) were varied.
- Simulations were run under a climate change scenario, including CO(2) fertilization.
Main Results:
- Varying demographic parameters resulted in diverse community structures, from monocultures to even PFT dominance.
- Ecosystem biomass predictions under climate change diverged significantly (1.5 to 27.0 kg C m(-2)).
- Observed ranges of biomass, LAI, GPP, and NPP did not significantly constrain model outcomes.
Conclusions:
- Demographic processes introduce substantial uncertainty into DGVM predictions.
- Accurate representation of these processes is critical for reliable ecosystem modeling.
- Further research is needed to refine the incorporation of demographic dynamics in DGVMs.
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