元谋干热河谷生态恢复区昆虫多样性研究

以元谋退化生态系统初始生态恢复中人工构建植被为研究对象,在样地调查的基础上,对比分析了退化生态系统和恢复生态系统昆虫群落多样性组成与结构的恢复状况及其对人工群落类型的生态响应。结果表明,植物群落组成是影响昆虫群落多样性的关键因子。与天然植被相比,混交林促进了昆虫在退化地的扩散和定居,物种多样性明显增加。主成分分析排序将6种生境分为两大类:第Ⅰ类为赤桉纯林,代表物种单一、林下空旷、环境干燥为特点的植被;第Ⅱ类为扭黄茅草坡、车桑子灌丛及赤桉 银合欢、赤桉 相思、相思 银合欢3种混交林,代表物种相对复杂,生境偏向湿润的植被。不同生境的特有昆虫和优势昆虫种类和数量分析表明,在3种混交林中,相思 合欢恢复的效果较赤桉 相思与赤桉 合欢显著,是最好的先锋群落植物混交模式,能够较快改良生境,提高其物种多样性。但由于造林面积较小,植被恢复时间短,受人为干扰较大,昆虫多样性恢复的效果还不明显。

Insect species diversity in ecologically restored area of Yuanmou dry and hot valley

The valleys in Southwest China are hot and dry because of rain shadow effect.On their slopes,the main vegetation is savanna.Due to heavy human disturbance,the vegetation has been devastated or severely degraded,resulting in severe water and soil erosion.Some tree species such as Eucalypt,Acacia,and Leucaena have been introduced for revegetation and shown good growth during the past ten years,but little is known whether the insect community diversity is recovered along with the revegetation.This study investigated the species diversity of insect community collected from six different vegetation formations in Yuanmou dry and hot valley,including two natural(twitch-grass and aalii brushwood) and four artificial vegetations(pure Eucalyptus,Eucalyptus camaldulensis+Leucaena leuacocephala mixed forest,Acacia auriculaeformis+Leucaena leucocephala mixed forest,and Eucalyptus camaldalensis+Acacia auriculaeformis mixed forest).The results showed that vegetation component was the key factor affecting the species diversity of insect community.Mixed forestation was an effective forestation technology,which promoted insect community diversity and helped local insect settle down in degenerated place.By using principal component analysis,the six vegetation formations were divided into tow groups.The first group was eucalyptus pure plantation,with its environment unitary and wilder,and the second group was made up by the other five vegetation formations,with richer species diversity and higher moisture.The characteristics and quantities of the dominant and peculiar insects in different vegetation formations showed that among three mixed forests,Acacia auriculaeformis+Leucaena leucocephala mixed forest was the best afforestation model which could improve environment and increase insect species diversity,although some factors such as human activity slowed down the recovery of insect community diversity.