Study on the Ecosystem Architecture Change
(2000-)

____ Supported as one of four projects under Ecosystem Change Research Programme,
which is under Frontier Reseach System for Global Change.
____ This project takes the modelling part of IGBP-GCTE-TEMA.

Members
  • Takashi Kohyama (Hokkaido University, Sapporo) __ project organizer
  • Takuya Kubo (Hokkaido University, Sapporo)
  • Akio Takenaka (National Institute of Environmental Science, Tsukuba)
    cooperative members
  • Ichiro Terashima (Osaka University, Osaka)
  • Kouki Hikosaka (Tohoku University, Sendai)
  • Kiyoshi Umeki (Hokkaido Forest Research Institute, Bibai)
  • Akihiro Sumida (Hokkaido University, Sapporo)
  • Naoaki Tashiro (Kyushu University, Ashoro)
  • Makizoh Suzuki (Hokkaido University, Sapporo)

    Outline
    A dynamic global model to forecast long-term changes in terrestrial ecosystems in response to climate and environment change is developed in this component. The three dimentional architecture of ecosystems is formed by plant growth, and at the same time it does regulate biological processes. Therefore this component will centre on the modelling of constructiion and regulation of the ecosystem architecture. It establishes the model of ecosystem change in a wide geographic scale, based on the fine-scale functional model of architectural regulation.

    (1) The Shoot Module Model
    The foliage architecture plays a leading role in organic production of in the terrestrial ecosystems. Modelling changes in foliage architecture is thus essential to account for how organic production responds to environmental changes. Basic unit constituting the foliage architecture is a shoot (a branch with foliage leaves). Physiological processes of individual shoots receive control from resource heterogeneity that is in turn regulated by the architecture. This feedback regulation between shoots and environment is one of the main factors that maintain and stabilise the terrestrial ecosystems. This sub-component will develop the functional model of shoot module populations and simulate the environmental regulation of physiological processes at shoot levels (the shoot-module-based models). This enables the parameterisation of environmental feedback at the integrated individual tree level. Ecosystem change is then simulated by the individual-tree-based models, which is functionally linked to shoot-level physiological processes.

    (2) The Forest Change Model
    Forest ecosystems are the enormous carbon stock in the land, and is predicted to be increasing the speed of carbon assimilation with increasing atmospheric carbon dioxyde. Using repeated census data of trees in forest research plots which are located along the latitudinal gradient in East Asia, the simulator for a forest-stand scale (a few hectares) will be developed. The simulator is assembled based on the module model explained in (1), and aimed to predict each forests' carbon balance and its changes. Henceforth the geographical dynamics of forest vegetation is modelled focusing upon latitudinal gradient from tropical forests to subarctic forests. It is predicted that as the global warming proceeds, long-term time lags can result at boundaried between climatic forest zones. The geographic-scale dynamic models are capable of quantitative prediction of those time lags. Combining this with monitoring and parametorarization of terrestrial ecosystem distribution, which are developed by a sister project "Study on the Ecosystem Geographical Distribution Change", is expected to propose the dynamic global model of terrestrial ecosystems.

    Query to this page ____ kohyama@ees.hokudai.ac.jp