Ecology 6th Edition by Charles Krebs

Exercise 2

English yew (Taxus baccata) is an evergreen tree with an average life span of 500 years (Hulme 1996). The regeneration potential of local sites will determine the future distribution of this tree, and seed predators, seedling herbivores, or suitable microsites for germination and growth are the three factors that may limit yew distribution on a local scale. Discuss what observations could distinguish between biotic limitation and abiotic microsite limitation of yew distributions.