Landscape Simulation Model

Landscape simulation model. Transition pathways diagram for state-transition simulation model integrated with stock-flows (STSM-SF) for sagebrush-steppe vegetation growth and cover change used to simulate potential habitat restoration at three greater sage-grouse (Centrocercus urophasianus) population core Priority Areas for Conservation (PAC) in the Great Basin, USA. Boxes in the STSM (A) represent discrete vegetation state classes, and lines and arrows represent succession, fire, non-native species invasion, (e.g., cheatgrass (Bromus tectorum)), pinyon-juniper encroachment, and post-fire restoration transitions between state classes. Transitions in the STSM were used to trigger different levels of percent cover gain (e.g., undisturbed annual growth, post-fire passive regeneration, planting restoration) and loss (e.g., fire) in a stock-flow (SF) submodels (B) of component cover change (CC). The six components were tracked as continuous (% cover) state variables for each cell in the STSM model and included sagebrush (SAGE), perennial herbaceous/grass (PG), annual herbaceous/grass (AG), non-sagebrush shrub (NSS), pinyon-juniper conifer (PJC), and bare ground (BG) and were used to trigger feedbacks and deterministic transitions. Vegetation growth and transitions were modeled within resistance and resilience (RR) landscape strata to incorporate heterogeneity in vegetation component cover change and transition probabilities associated with soil moisture, temperature, and elevation gradients across sagebrush ecosystems. (Figure 1 in Using state-and-transition simulation models to scope post-fire success in restoring greater sage-grouse habitat from ecological modelling).