Question

Ecological succession leads to the sustainability of life in an ecosystem. Succession is the observed process of change in the species structure of an ecosystem. The community begins with relatively few pioneering plants and animals and develops through stages of increasing complexity until it becomes stable. Succession may be initiated either by formation of new, unoccupied habitat such as the formation of an island or by some form of disturbance such as fire in an existing ecosystem. Succession that begins in new habitats, uninfluenced by pre-existing communities is called primary succession, whereas succession that follows disruption of a pre-existing community is called secondary succession.

What natural event would most likely cause succession in a grassy field?

A) grass leaves injured by a frost
Eliminate

B) grass is blown flat by a strong wind


C) soil remains wet for several days after a heavy rain


D) grass plants die after a long period of no rainfall

I have all the information so don't delete my question this time .  :)

Answer 1

I'd say D...it sounds like the old species would have to completely die out before any new succession could occur in a pre-existing environment and D is the only option that guaruntees such a phenomena.

Answer 2

Answer: D) grass plants die after a long period of no rainfall.

An ecological succession is a series of changes occurs in a biological community living in an ecosystem with respect to changes occurring in abiotic or non living factors such as soil, availability of rain and sunlight with respect to time until the ecosystem attains stability. A primary succession occurs in a region of complete barren land mass like glacier retreat, volcanic eruption. A secondary succession occurs in a region of previously colonized ecosystem which has been destroyed by calamities like drought, forest fires.

In this case, grass plants die after a long period of no rainfall can result in secondary succession in a grassy field, because although the plants die but the soil will be fertile enough to sustain the growth of new plants if the area again receives the rainfall. Also, the area might have remains of previously growing grass like seeds, roots which will help in growth of new plants and will result in succession.