Overview

While climatic conditions primarily determine the distribution and functioning of plant ecosystems, plant ecosystems also affect the climate, mainly through evapotranspiration, albedo, carbon cycle, and land surface roughness. The degree, the sign (negative or positive), and the geographical distribution of the vegetation feedback on climate will all play a role in determining the final state of climate and the final state of distribution and functioning of terrestrial ecosystems.

For reliable predictions of global climate changes, the development of integrated terrestrial ecosystem models that encompass biogeochemical processes and vegetation dynamics is of utmost importance. However, the predicted long time lag between climatic changes and the adaptation of plant ecosystems to the new climate adds a layer of complexity. These time lags, which are a complex and diverse function of many factors, including seed dispersal, establishment conditions/rate, and growth rate, currently prevent us from making reliable predictions.

To address this challenge, Dynamic Global Vegetation Models (DGVMs) have been developed. These models have the potential to simulate changes in ecosystem functions (such as carbon and water flux) and ecosystem structures (such as distribution and composition), offering a promising avenue for future research in the field of climate-ecosystem interactions.

Among existing DGVMs, SEIB-DGVM only simulates local area interactions of individual trees within a spatially explicit virtual forest; several sample plots are placed at each grid box, and the growth, competition, and decay of each individual tree within the plots are considered by considering the light conditions of each tree surrounded by other trees.

This representation of plant dynamics has essential advantages over previous DGVMs:

  1. Competition and succession dynamics are adequately represented, and hence, the response of the ecosystem to climatic change would be reasonably predicted.
  2. Formation and recovery of forest gaps and subsequent carbon behavior can be included.
  3. Information on the forest structures and dynamics can be directly applied for parameter estimation and validation without introducing many additional assumptions.

The SEIB-DGVM’s development is almost complete. After verifying its reliability, we will incorporate it into the Kyousei2-Integrated-Synergic-Sytem-Model-of-Earth (KISSME), which simulates possible consequences of climate-ecosystem interactions on the Earth’s future environment.

* Description manuscript of the latest version of the SEIB-DGVM –> Model_description(240902).docx