MacArthur-Wilson island biogeography and the species-area power law
The MacArthur-Wilson (1967) species-area relationship S = cA^z predicts that fragmented habitat patches hold fewer species. Halving area reduces species by 2^z ≈ 19% (for z=0.25). Each patch reaches equilibrium between colonization (c·(S_pool−S)·e^(−d)) and extinction (e·S/A). Habitat loss is thus a multiplicative biodiversity threat: even without direct killing, fragmentation drives species toward local extinction.