The Model discussed in [8] examines the impact of human activities on environmental and natural resource sustainability. The premise of the model is that landscape properties such as fragmentation, connectivity, spatial dynamics, and the degree of dominance of habitat types, are influenced by market processes, human institutions, landowner knowledge, and ecological processes. Therefore, modeling environmental sustainability of human-dominated landscapes will benefit from the integration of human and ecological processes.
Figure 1: LUCAS modules of the Olympic Peninsula/Southeastern Appalachian
Biosphere Integration Model .
The structure adopted for LUCAS consists of three subject modules linked by a common database (see Figure 1). The first LUCAS module contains the socioeconomic models that are used to derive transition probabilities associated with changes in land cover. These probabilities are computed as a function of socioeconomic driving variables including, (1) transportation networks (access and transportation costs), (2) slope and elevation (indicators of land-use potential), (3) ownership (land holder characteristics), (4) land cover (vegetation), and (5) population density. Preliminary analysis of the Little Tennessee River Basin [5] revealed that land-cover change is most likely to occur on private land, near a paved road, on flat low elevation land, and close to the major urban center of the watershed (Franklin, NC). As demonstrated in [15], most of the transitions in land cover are forest coverting to grassy/brushy and unvegetated cover types. The construction of transition probability matrices that describe such changes in land cover are discussed in Section 2.
The landscape-change model resides in the second LUCAS module (see Figure 1). This module receives as its input the transition matrix produced in the socioeconomic models (Module 1), and accesses the same spatial database of driving variables. A single iteration of the landscape-change model produces a map of land cover that reflects socioeconomic motivations behind human land-use decision making (represented in the transition probability matrix).
The impact models defined in the third module of LUCAS (see Figure 1) utilize the land-cover maps produced by the landscape-change module to estimate impacts to selected environmental and resource-supply variables. These environmental variables include the amount and spatial arrangement of habitat for selected species and changes in water quality caused by human land use. Potential resource-supply variables include timber yields and real estate values. For simulations of land-cover change in the Little Tennessee River Basin, for example, output maps of the persistence of the animal and plant species in Table 1 can be generated by LUCAS.
Table 1: Species' habitat impacts modeled by LUCAS.