PARENT SESSION
Symposium #25: Scaling information from plots or regions to landscapes: when do details matter?.
Organized by: DPC Peters and JE Herrick
Thursday, August 8. 9:00 AM to 11:30 AM. Crystal Ballroom, TCC.
Spatial non-interactive approaches to scaling: dynamics in place.
Crist, Thomas*,1, Ojima, Dennis2, Neilson, Ronald3, 1 Miami University, Oxford, OH2 Colorado State University, Fort Collins, CO3 USDA Forest Service, Corvallis, OR
ABSTRACT- The non-linear dynamics of ecological systems pose several challenges to evaluating the spatial and temporal patterns of disturbance, community composition, and ecosystem processes. Integration of ecological processes across multiple spatial and temporal scales is possible when spatial patterns of environmental factors are defined across topo-edaphic gradients. We consider several approaches. First, we examine how broad-scale processes influence patterns of species diversity across scales using examples from plants and insects. Spatially explicit designs can be used to assess scales of dependency in population distributions, species diversity, or composition, whereas hierarchical designs can be used to partition regional diversity into the relative contributions of habitat and landscape heterogeneity. Next, we consider how patterns of change are modeled using examples of spatially explicit simulations of vegetation dynamics and ecosystem processes. Simulations of landscape dynamics involve interactions among different landscape elements represented by a network of grid cells, as well as stand dynamics within cells. Recent efforts attempt to simulate sub-grid cell heterogeneity by characterizing topo-edaphic factors or age-class differences within a cell. For structural variables, such as slope-aspect features, fine-scale heterogeneity can be incorporated explicitly, whereas disturbance and vegetation dynamics among sub-cells must be described statistically rather than spatially. Finally, we consider how these non-interactive and interactive approaches to spatial scaling of landscape patterns and dynamics can provide different insights into community and ecosystem processes.
KEY WORDS: spatial dynamics, landscape heterogeneity, community patterns, ecosystem processes