Question

in both types of succession, the intermediate stages occur as the area is gradually changed by successive communities of organisms. for example, the grasses and shrubs present in the early stages eventually die: as they decompose, they build up the thickness and nutrient content of the soil. eventually the soil becomes thick and rich enough to support trees; small trees are followed by large trees. when a community is established in which each species maintains a relatively stable number of individuals, the ecosystem has reached its climax. secondary succession achieves climax much more rapidly than primary succession because an area that was previously occupied is richer in nutrients than an area that was not previously occupied. summary sentence: (the author is saying that...)

Explanation:

The text discusses ecological succession. It explains that in both primary and secondary succession, intermediate stages occur as communities change the area. For example, grasses and shrubs decompose to build soil, allowing trees. When a stable community (climax) is reached. Secondary succession reaches climax faster as previously - occupied areas are more nutrient - rich.

Answer:

The author is saying that in ecological succession (both primary and secondary), communities of organisms gradually change an area. In the process, early - stage organisms (like grasses and shrubs) decompose to improve soil. Eventually, a climax community (with stable species numbers) is formed. Secondary succession reaches climax more rapidly than primary succession because previously - occupied areas have more nutrients.