Earth system models (ESMs) have been developed to represent the role of terrestrial ecosystems on the energy, water, and carbon cycles. However, many ESMs still lack representation of within-ecosystem heterogeneity and diversity. In this paper, we present the Ecosystem Demography model version 2.2 (ED-2.2). In ED-2.2, the biophysical and physiological processes account for the horizontal and vertical heterogeneity of the ecosystem: The energy, water, and carbon cycles are solved separately for a series of vegetation cohorts (groups of individual plants of similar size and plant functional type) distributed across a series of spatially implicit patches (representing collections of microenvironments that have a similar disturbance history).We define the equations that describe the energy, water, and carbon cycles in terms of total energy, water, and carbon, which simplifies the differential equations and guarantees excellent conservation of these quantities in long-term simulation (<0.1%error over 50 years).We also show examples of ED-2.2 simulation results at single sites and across tropical South America. These results demonstrate the model's ability to characterize the variability of ecosystem structure, composition, and functioning both at stand and continental scales. A detailed model evaluation was conducted and is presented in a companion paper (Longo et al., 2019a). Finally, we highlight some of the ongoing model developments designed to improve the model's accuracy and performance and to include processes hitherto not represented in the model.
Bibliographical noteFunding Information:
This research has been supported by the Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (grant no. 200686/2005-4), the NASA Earth and Space Science Fellowship (grant no. NNX08AU95H), the National Science Foundation, Office of International Science and Engineering (grant no. OISE-0730305), the National Science Foundation (grant no. ATM-0449793), the National Aeronautics and Space Administration (grant no. NNG06GD63G), and the Fundac?? de Amparo ? Pesquisa do Estado de Sa? Paulo (grant no. 2015/07227-6).
Financial support. This research has been supported by the Con-
Acknowledgements. The research was partially carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. We thank the reviewers Ian Baker and Stefan Olin, as well as Miriam Johnston, Luciana Alves, John Kim, and Shawn Serbin for suggestions that improved the manuscript, and Alexander Antonarakis, Fabio Berzaghi, Carl Davidson, Istem Fer, Miriam Johnston, Geraldine Klarenberg, Robert Kooper, Félicien Meunier, Manfredo di Porcia e Brugnera, Afshin Pourmokhtarian, Thomas Powell, Daniel Scott, Shawn Serbin, Alexey Shiklomanov, Anna Trugman, Toni Viskari, and Xiangtao Xu for contributing to the code development. The model simulations were carried out at the Odyssey cluster, supported by the FAS Division of Science, Research Computing Group at Harvard University. Marcos Longo was supported the NASA Postdoctoral Program, administered by Universities Space Research Association under contract with NASA. Abigail L. S. Swann was supported as a Giorgio Ruffolo Fellow in the Sustainability Science Program at Harvard University, for which support from Italy’s Ministry for Environment, Land and Sea is gratefully acknowledged.
All Science Journal Classification (ASJC) codes
- Modelling and Simulation
- Earth and Planetary Sciences(all)