PARENT SESSION
Oral Session #12: Landscape Ecology: Theory and application. Presiding: C. Johnston.
Monday, August 6, 2001. 1:00 PM to 5:00 PM. Madison Ballroom D.
On the topoclimatic and bottom-up modeling approaches in a rugged mixed-hardwood forest.
KANG, SINKYU1, LEE, DOWON1, 1
ABSTRACT- Rugged topography advocates topoclimatic modeling on ecological variables. Since local topography is sensed differentially across spatial resolutions it can have potentially influences on the model predictions. In this study, two scaling hypotheses were tested using field observations and the model simulations. In a rugged forest, the landscape-scale soil respiration was hypothesized significantly different from the plot-scale observation of soil respiration. In the variables closely related with local topography, the model predictions at a coarse spatial resolution were hypothesized inconsistent with the predictions at a fine resolution. Both hypotheses tested the needs for topoclimatic and bottom-up modeling approaches, respectively. Plot-scale field experiment was conducted and topoclimatic modeling was implemented in two different resolutions (30m and 1100m). Predicted annual soil respiration showed two-fold spatial variation. This indicates that topographic and microclimatic effects should be adjusted to use the plot-scale soil respiration as a surrogate of the landscape-scale soil respiration in the rugged forest. Comparing distinct topographic effect on solar radiation and LAI, the effect diffused in soil respiration and soil temperature. The bottom-up modeling approach was advocated only for solar radiation to derive the coarse-scale prediction from fine-scale prediction. Even in the variables weakly related with topography, the topoclimatic modeling was, however, still advocated for the coarse-scale prediction.
KEY WORDS: topoclimatic model, bottum-up approach, soil respiration, environmental variables