松材线虫侵袭引发的植被演替对鸟类群落的影响

松材线虫(Bursaphelenchusxylophilus)是引起严重森林病害的外来物种,可能导致森林生态系统急剧退化。为了探讨在松材线虫侵袭所引起的森林演替过程中植被结构变化对鸟类群落的影响,我们研究了这些常绿阔叶演替林中的鸟类群落结构。2004年5–6月,我们在浙江省宁波市选择了分别处于3个不同演替阶段的7个样地:包括象山县被松材线虫侵袭5年后的常绿阔叶灌丛和侵袭12年后的常绿阔叶林样地各3个,同时在天童国家级森林公园选择了约40龄的常绿阔叶林样地1个。结果显示,在常绿阔叶灌丛和松材线虫侵袭12年后的常绿阔叶林中,鸟类物种多样性和丰富度均显著高于约40龄常绿阔叶林;3类栖息地的鸟类多度、均匀度均无显著差异;在侵袭12年后的常绿阔叶林中鸟类群落最丰富。多元回归分析结果显示,立地年龄是影响鸟类群落组成的主要因素。

Avian community response to vegetation succession caused by the pinewood nematode in Zhejiang, China

The pine wood nematode (Bursaphelenchus xylophilis) has been causing widespread losses to pines in China since it was first found in 1982. It can bring about forest degradation. To study the effect of nematode-induced forest succession on avian communities, we chose three forest types at different seral stages, including evergreen broad-leaved coppice infested by the pine wood nematode for five years and evergreen broad-leaved forest infested for 12 years, both from Xiangshan County, Zhejiang, and one 40-year-old evergreen broad-leaved forest from Tiantong National Forest Park, Zhejiang. The results showed that bird species richness and diversity were significantly greater in the two infested evergreen broad-leaved forest types with little difference between them, while there existed little difference in bird abundance and evenness in the three types. It suggested that the evergreen broad-leaved forests at early successional stage had higher bird species richness and diversity. Stepwise multiple regression models of bird community variables indicated that microhabitat feature such as stand age was an important predictor of bird community composition.