长江三峡库区昆虫丰富度的海拔梯度格局--气候、土地覆盖及采样效应的影响  

The altitudinal pattern of insect species richness in the Three Gorge Reservoir Region of the Yangtze River: effects of land cover,climate and sampling effort

作　　者：刘晔[1] 沈泽昊[1] 

机构地区：[1]北京大学城市与环境学院生态学系,地表过程分析与模拟教育部重点实验室,北京100871

出　　处：《生态学报》2011年第19期5663-5675,共13页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30870432)

摘　　要：为了探讨长江三峡库区昆虫丰富度的海拔分布格局以及关键影响因子,针对库区记录的3517种昆虫及其中的害虫,我们整理了这些物种的海拔分布范围数据,分析不同分类学水平、种域宽度等级和分类群的物种丰富度海拔分布模式,采用回归树方法探讨主导的影响因素,并检验相关的假说。结果显示:1)在科、属、种水平,三峡库区分布的昆虫和害虫丰富度均呈随海拔上升先增而后减的格局;狭域、中域和广域种具有显著不同的格局,但三个种域等级的昆虫物种丰富度在海拔1400m以上均显著下降,而害虫丰富度在海拔1200m以上即显著下降。2)对记录昆虫种数>20的科进行TWINSPAN分类,得到物种丰富度海拔格局的4种主要模式;尽管不同程度受采样效应的影响,4种模式均属于单峰格局;3)库区土地利用类型的海拔变化对昆虫、害虫物种丰富度海拔分布具有首要和直接的影响;水热平衡或初级生产力是影响昆虫海拔格局的主导气候因子;而1月均温=0℃可能是限制大多数昆虫物种分布上限的临界温度。上述结果表明,三峡库区的昆虫物种丰富度及其不同组分均具有典型的单峰分布格局,这种格局是人类活动与气候梯度综合作用的结果,但前者的作用更为直接,主要体现在土地利用的海拔梯度变化。这些认识对昆虫多样性资源管理和农林业害虫防治具有参考意义。As an important component of biodiversity,the distribution pattern and the determinants of insect diversity has attracted increasing attention.To explore the distribution of insect species richness along the altitudinal gradient in the Three Gorges Reservoir Region,we conducted a series of analyses on a database of 3517 insect species recorded within this area.By compiling the altitudinal range of these species,including the herbivore pest insects,we explore the altitudinal patterns of insect diversity of different taxonomic levels and particular families,and by different range size classes.Regression tree modeling was then applied to uncover the prominent factors regulating the altitudinal patterns of species richness of total insects and pest insects.The analysis revealed that： 1） a unimodal richness pattern along the elevation gradient was found consistently for different systematic levels.Although the patterns are significantly different for the species belonging to the restricted,middle,and broad range size classes,the species richness of all three classes decrease prominently above 1400m a.s.l.,whereas the species richness of pest insect begins to decline from 1200 m a.s.l.upwards;2） TWINSPAN was applied and classified the insect families into 4 modes with different altitudinal patterns of species richness.Although the estimates are biased because of greatly unbalanced sampling,all the four modes are unimodal type;（3） the change of land cover composition along the altitudinal gradient plays a direct and primary role in regulating the patterns of all insects and pest insects species richness.Water-energy or primary productivity indicated by the actual evapotranspiration follows as a prominent climatic variable for the pattern of insect species richness.The inflection point of species richness is probably controlled by the isoline of 0℃ in January,representing the threshold temperature for the upper limit of the majority of insect species.We suggest that the altitudinal patterns of insect species

关 键 词：昆虫 物种丰富度 海拔分布格局 TWINSPAN分类 回归树 长江三峡库区 

分 类 号：Q948[生物学—植物学]