Info

Soil property map (Webb et al., 1993)

Rooting depth Water holding capacity

Topography map (ETOPO-5)

Altitude

Topography map (ETOPO-5)

CARBON CYCLE MODEL

CO2 in free atmosphere net ecosystem production

CO2 in canopy boundary layer

foliage

translocation

stem

root

litter

decomposition

Figure 1: Operational flow of the model simulation, including schematic diagram of the carbon cycle in the terrestrial ecosystem (For colour version, see Colour Plate Section).

calculated by the CO2 budget: NPP = GPP-AR

where GPP is gross photosynthetic production and AR the autotrophic respiration. GPP responds to irradiance, ambient CO2 level, temperature, vapor pressure deficit, and soil water content, while AR is composed of maintenance and construction components that depend on temperature and biomass growth rate, respectively.

The estimation of GPP is based on a method that uses Monsi-Saeki theory, by which ecophysiological findings at the single-leaf level are scaled up to the canopy level (Monsi et al., 1973; Terashima and Hikosaka, 1995). Single-leaf LUE (apparent quantum yield, mol CO2 mol-1 photon) is defined as a constant for C4 plants and as a variable for C3 plants: LUE(C4leaf) - 0.05 (6)

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