Carbon Allocation In Dry and Wet Years A Simulation Using BIOME-BGC for Excel Joshua Gray 9/2007

Model Initialization Meteorological Data for Missoula, MT from 1950-1993 Tree specific parameters typical of evergreen needle leaf stands 1m deep loamy soil: 30% sand, 50% silt, 20% clay

1976 and 1980 Precipitation 1976: 24.1cm total precipitation

GPP in Wet and Dry Years

1980 Leaf C values higher overall We observe the potential decreasing as additional Leaf C is generated Rate of Leaf C addition decreases with decreasing soil water potential Amount of Leaf C decreases when we reach the point of stomatal closure

Ratio of NPP/GPP is essentially constant: 1976: 50% and 1980: 57% (intercept is forced through the origin) This is higher than reported in the text (Oregon Transect, Harvard Forest, Australia, New Zealand all about 46%)