Question

I need a full answer please.

4. We learned commonness and rarity in Chapter 9. Populations that are most threatened by extinction, have restricted geographic ranges, narrow habitat tolerances, and small local populations. You goal is to increase the size of the population. Search different factors to decrease vulnerability to extinction instead of using geographic ranges, habitat tolerances and local population (from books, journal articles, on-line, and etc.). Your species can be either animals or plants, or both (2.5pt).

Answer 1

Trophic redundancy decreases vulnerability to extinction. More complex food webs will be less vulnerable to secondary extinctions due to greater trophic redundancy that can buffer against the effects of species loss. Trophic redundancy, rather than species richness, is responsible for the observed difference in secondary extinctions between the simple and complex communities. Trophic link redundancy can provide robustness against secondary extinction cascades following the harvesting of one species under this particular secondary extinction mechanism. Additionally urban food webs have lower trophic redundancy i.e. fewer species at each trophic level.