state true and false a. Abiotic conditions in edge habitat frequently diverge from those in a patch of habitat. B. Each and every keystone species is an ecosystem engineer. C. Leaf cutter ants gather scraps of leaves, use those scraps to grow fungi, and then consume those fungi as nourishment. This is an illustration of a rare biological phenomena. D. More species are likely to benefit from protecting undeveloped habitat on the Channel Island than from maintaining an equivalent area of habitat in California. e. Large population sizes and high reproduction rates are two aspects that make squirrels particularly susceptible to extinction. .