题目解析：
本题为事实信息题，题干关键词“disturbance”在整段中重复出现，无法通过定位词缩小阅读范围，因此保险起见我们需要阅读整段文字，然后用排除法做题。
A选项说干扰分好几个阶段进行。而文章中只提到“Each stage of succession is referred to as a successional sere.”这句话是说演替的每一阶段都被称为一个演替系列。整段文字完全没有提到disturbance分阶段进行，故排除。B选项说干扰可以由自然因素和人为因素造成。我们定位到这句话“Volcanic eruptions, retreating glaciers, and bare sand dunes are examples of sites subject to primary succession, while clear-cutting of forests, wild fires, and hurricanes are examples of sites subject to secondary succession.”这句话中例举了原生演替和次生演替发生的场所，其中火山爆发、冰川退缩、裸露沙丘、野火、飓风都属于自然因素，而森林砍伐很明显属于人为因素，因此B选项正确。C选项说disturbance会加剧火山爆发，而文中只说火山爆发之处是原生演替发生的场所，也就是说火山爆发自身就是一个disturbance。所以C选项逻辑错误，排除。D选项说disturbance对演替速率没有影响，我们定位到本段最后一句“The rate of succession is dependent upon the extent of the disturbance and the availability of appropriate seeds for recolonization.”这句话说演替速率取决于受到干扰的程度以及合适的再生植物种子的有效性。所以D选项与原文矛盾，故排除。
Succession is a continuous change in the species composition, structure, and function of a forest through time following disturbance. Each stage of succession is referred to as a successional sere. The final stage of succession, which is generally self-replacing, is referred to as the climax sere. There are two major types of succession: primary and secondary. Primary succession is the establishment of vegetation on bare rocks or radically disturbed soil. Secondary succession is the reestablishment of vegetation following a disturbance that killed or removed the vegetation but did not greatly affect the soil. Volcanic eruptions, retreating glaciers, and bare sand dunes are examples of sites subject to primary succession, while clear-cutting of forests, wild fires, and hurricanes are examples of sites subject to secondary succession. Hundreds to thousands of years are required for primary succession to reach the climax sere, compared to decades to hundreds of years for it to occur in secondary succession. A longer time is needed to reach the climax sere for primary than secondary succession because soil development must first take place in primary succession. The rate of succession is dependent upon the extent of the disturbance and the availability of appropriate seeds for recolonization. 
