渝西地区火烧迹地不同植被恢复方式下的物种多样性动态

Dynamics of Species Diversity of Burn Blanks Under different restoration ways in Western Chongqing

以“空间序列”代替“时间序列”的研究方法对渝西地区不同恢复方式下不同年龄的火烧迹地进行了调查研究，结果表明：火烧迹地的植被均匀度、丰富度和Shannon-Wiener指数等随恢复年限的变化曲线在人工恢复和自然恢复两种情况下有很大差异。在本实验中，看不出两种恢复方式的不同是否能决定群落最终的物种多样性水平，但是不同的恢复方式可以加快或减缓物种多样性恢复的过程。本实验还表明，在人工恢复的35年以内。多样性的恢复是一个“S”形变动的过程，可以缩短灌木丛阶段的年限，加快乔木层的建成，同时也会促使该类型林区更长时间的停留在针叶林阶段，推迟该林区向顶级群落的演替进程；在自然恢复的40年以内。多样性的恢复是一个逐渐上升的过程，在最初的8年以内，其多样性不如人工恢复，但在恢复40年左右的时候，其多样性却可以达到一个比人工恢复高很多的一个水平。

Dynamics of species diversity with different times after burning was studied on the burn blanks in western Chongqing by using ＂the sequence of space for replacing the sequence of time＂ method. The results indicated that, there is a significant variance on Eveness curve, Richness curve, and Shannon-Wienner index curve among the rehabilitated communities under management and in nature. It is not clear whether different restoration ways can lead to the different ultimate species diversity of these communities but the result indicate that different restoration ways can led to the rehabilitated process quickened or slow down in the studied communities. Species diversity curve shows a S-shaped type under artificial restoration but ascend gradually in natural restoration. In those rehabilitated communities under artificial restoration , the shrub stage was shorten, the tree layer was built in relatively shorter time, conifer tree stage became longer, and the succession process to the climax community was suspended.,while in those communities by natural restoration,the species diversity is lower in the first 8 years, but much higher than that by artificial restoration after 40 years.