Terrestrial Ecosystems and the Global Land System Framework
Changes in land ecosystems due to changes in climate are important considerations in policy discussions. In addition, climate-driven changes in the terrestrial biosphere affect climate dynamics, through feedbacks on both the carbon cycle and the natural emissions of trace gases.
The terrestrial component of the IGSM includes dynamically linked hydrologic and ecologic models in a Global Land System framework, as depicted in the diagram below.
Hydrologic processes and surface-heat fluxes are represented by the Community Land Model (CLM), which is based on a multi-institutional collaboration of land models. Within the IGSM, CLM is dynamically linked to the global Terrestrial Ecosystems Model (TEM), developed by The Ecosystems Center at the Marine Biology Laboratory (MBL). Within the IGSM, TEM is used to simulate the carbon dynamics of terrestrial ecosystems. Methane and nitrogen exchange are considered through the Natural Emissions Model (NEM), which is driven by dynamic inputs from both TEM and CLM. The coupled CLM/TEM/NEM model system represents the geographical distribution of global land cover and plant diversity through a mosaic approach, in which all major land cover types and plant functional types are considered over a given domain, and are area-weighted to obtain aggregate fluxes and storages.
The Global Land System Framework is documented in Schlosser et al., 2007 (Report 147).
