海拔变化对双翅目昆虫群落多样性的影响及机制探讨——以西双版纳地区为例

Effects of altitude change on Diptera community diversity and its mechanism—a case study of Xishuangbanna,Yunnan,China

本研究于2019年8月和10月在西双版纳采用样线法对双翅目Diptera昆虫群落进行调查,对不同海拔段(500~750 m(海拔段Ⅰ)、750~1000 m(海拔段Ⅱ)、1000~1250 m(海拔段Ⅲ)、1250~1500 m(海拔段Ⅳ))的双翅目昆虫进行了多样性和生态位宽度比较,旨在通过探讨不同海拔段双翅目昆虫多样性和生态位宽度的差异,揭示海拔对双翅目昆虫群落多样性的影响及机制。结果显示:(1)物种组成:共采集标本1217头,隶属于36科307种,其中海拔段Ⅰ有19科57种141头、Ⅱ有20科113种262头、Ⅲ有26科131种459头、Ⅳ有30科119种355头。(2)多样性比较:不同海拔段双翅目昆虫群落的多度、物种丰富度和Chao-1估计值都有显著差异(P<0.05)。海拔段Ⅱ、Ⅲ、Ⅳ的多度、物种丰富度和Chao-1估计值显著大于海拔段Ⅰ。(3)群落结构:不同海拔段的双翅目昆虫群落结构存在显著差异(P<0.001);其中海拔段Ⅰ、Ⅱ与海拔段Ⅲ、Ⅳ的双翅目昆虫群落结构存在显著差异(P<0.05)。(4)相关性分析:双翅目昆虫多样性与每月最高温度、最低温度、月均温和降水呈显著负相关,与海拔呈显著正相关。(5)生态位宽度:随着海拔段升高,生态位宽度值普遍增大,海拔段Ⅳ上生态位宽度值达到最大的科最多;生态位宽度值小的科集中分布在海拔段Ⅲ、Ⅳ。在西双版纳地区海拔500~1500 m范围内,随海拔上升,双翅目昆虫多样性及生态位宽度值普遍增大。在全球气候变暖的背景下,生态位宽度可以解释物种的海拔分布格局。

In this study,using line transect method,the Diptera community was investigated in Xishuangbanna,Yunnan,China in August and October 2019,the diversity and niche width of the Diptera community at different altitudes(500~750 m denote as altitude section Ⅰ,750~1000 m as altitude section Ⅱ,1000~1250 m as altitude section Ⅲ,1250~1500 m as altitude section Ⅳ)were compared.The aim of this study was to reveal the effects of altitude on Diptera community diversity and its mechanisms by analyzing the differences of Diptera diversity and niche width at different altitudes.The results showed that(1)Species composition:A total of 1217 Diptera specimens were collected in this study,belonging to 307 species,36 families.A total of 141 specimens were collected in altitude section 1,belonging to 57 species,19 families.262 specimens in altitude section Ⅱ,belonging to 113 species,20 families.459 specimens in altitude section Ⅲ,belonging to 131 species,26 families.355 specimens in altitude section IV,belonging to 119 species,30 families.(2)Diversity comparison:There were significant differences in abundance,species richness and Chao-1 estimated value of Diptera community in different altitudes(P<0.05).The abundance,species richness and Chao-1 estimated value of altitude section Ⅱ,Ⅲ and Ⅳ was significantly higher than those of altitude section Ⅰ.(3)Community structure:There were significant differences in Diptera community structure at different altitudes(P<0.01),and there were significant differences in Diptera community structure between altitude section Ⅰ,Ⅱ and Ⅲ,Ⅳ(P<0.05).(4)Correlation analysis:Diptera diversity was negatively correlated with maximum temperature,minimum temperature,monthly mean temperature and precipitation of month,and positively correlated with altitude.(5)Niche width:With the elevation increasing,the niche width values generally increased,and most families had the maximum niche width in altitude section Ⅳ.Families with small niche width were concentrated in altitude section Ⅲ and Ⅳ.Within the scope of Xishuangbanna,Yunnan,China at altitude of 500 to 1500 m,niche width and diversity of Diptera has increased with the increase of altitude.In the context of global warming,niche width can explain the distribution pattern of altitude of species.