Figure 2.

Interactive range‐limit theory (iRLT) provides predictions for expansion and contraction along each edge. For high‐latitude/altitude limits, (a) range contraction (e.g. of bobcat) occurs when abiotic stress is greater (increased snow) than the influence of positive biotic factors and (b) range expansion occurs when positive biotic factors (e.g. more prey) are greater than abiotic stress. For low‐latitude/altitude limits, (c) range contraction (e.g. of Canada lynx) occurs when negative biotic interactions (increased competition) are greater than the influence of abiotic factors (d) and expansion occurs when this dynamic is reversed. In summary, positive biotic factors can expand the range along upper limits despite the presence of stressful abiotic factors, and expansion along lower limits can result if negative biotic interactions are buffered by stress from abiotic factors; contraction occurs in the absence of these indirect and mediating factors along either edge