Environmental gradients of resilience and resistance
Conceptual model of (A) resilience to disturbance and (B) resistance to invasives as they relate to three environmental gradients: soil temperature and moisture regimes, elevation, and productivity. Soil moisture availability is also modified by soil characteristics. (A) The solid blue line in the top graph is the resilience as it relates to elevation (dashed dark blue line above and red line below adjust for aspect), soil temperature/moisture regimes, and productivity. (B) The solid green line in the bottom graph represents potential resistance to invasive annual grasses in the reference state, and the red line is the decline in resistance as a result of a site that is in an at-risk-phase (example depleted perennial herbaceous understory) or global climate change. Common plant communities along this gradient are Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis, ARTRw), mountain big sagebrush (A.t. spp. vaseyana, ARTRv), and mountain big sagebrush and snowberry (Symphoricarpos occidentalis, ARTRv-SYOR). (Chambers et al. 2014).