Modeling and evaluating ecosystem processes across a mountain divide
White JD, Running SW, Ryan KC, Keane RE, Thornton PE. 1995. Modeling and evaluating ecosystem processes across a mountain divide. Bulletin of the Ecological Society of America. 76(3):402
The Regional Hydro-Ecological Simulation System (RHESSys) is a spatially explicit ecosystem model that is used to estimate carbon, nitrogen, and water cycling by vegetation across a landscape. We used the RHESSys model to calculate ecosystem carbon allocation for two forested watersheds in Glacier National Park, Montana. We measured LAI values using a LiCor LAI-2000 to correlate with satellite radiometric data for model parameterization and found a linear relationship was found between LAI and satellite data given that the LAI were measured under diffuse radiation conditions. Stem carbon increment was calculated from collected tree core data for the past ten years. Predicted versus observed stem carbon demonstrated an overall agreement, however, comparison was difficult given that plot measurements were extrapolated to larger, predicted landscape values. Correlation between predicted and observed stem carbon was mostly a function of initial model carbon and nitrogen values. Root production was estimated at several plots using the difference between litterfall and soil CO2 evolution as measured by soda lime absorption. Correlation between litterfall and root production was a function of modeled water and nitrogen budgets.
- Type
- Journal Article
- Authors
- White, J; Running, S; Ryan, K; Keane, R; Thornton, P
- Units
- GLAC
- Keywords
- Ecosystem, IAR, Model, Monitoring, mountain divide, process