title: Different responses of functional traits and diversity of stream macroinvertebrates to environmental and spatial factors in the Xishuangbanna watershed of the upper Mekong River Basin, China.
abstract: Functional traits and diversity indices have provided new insights into community responses to stressors. Most traits of aquatic organisms have frequently been tested for predictability and geographical stability in response to environmental variables, but such tests of functional diversity indices are rare. We sampled macroinvertebrates at 18 reference sites (RS) and 35 disturbed sites (DS) from headwater streams in the upper Mekong River Basin, Xishuangbanna (XSBN), China. We selected 29 qualitative categories of eight traits and then calculated five functional diversity indices, namely functional richness (FRic), functional evenness (FEve), functional dispersion (FDis), functional divergence (FDiv) and Rao's Quadratic Entropy (RaoQ), and two trait diversity indices, namely trait richness (TR) and trait diversity (TD). We used combination of RLQ and fourth-corner to examine the response of traits and functional diversity to the disturbance and environmental variables. We used variance partitioning to explore the relative role of environmental variables and spatial factors in constraining trait composition and functional diversity. We found that the relative frequency of ten trait categories, and the values of TD, TR, FRic and FDis in RS were significantly different (p<0.05) from DS. In addition, the seven traits (except for "habit") demonstrated a predictable response of trait patterns along the integrative environmental gradients. Environmental variables significantly contributed to most of the traits, functional diversity and trait diversity. However, spatial variables were mainly significant in shaping ecological traits, FRic and FEve. Our results confirm the dominant role of environmental variables in the determination of community trait composition and functional diversity, and substantiate the contribution of spatial vectors in explaining the variance of functional traits and diversity. We conclude that the traits "Refuge", "External protection", "Respiration" and "Body shape", and diversity indices FDis, TD, and TR are promising indicators of stream conditions at XSBN.
authors.affiliation: Department of Entomology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.affiliation: Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, 210009, Jiangsu, PR China.
authors.forename: Weifang
authors.initials: W
authors.lastname: Yang
authors.affiliation: Department of Entomology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, PR China.
authors.forename: Yunlei
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Bioscience and Arctic Research Centre, Aarhus University, Central Jutland 8000, Denmark; Sino-Danish Centre for Education and Research, University of Chinese Academy of Science, Haidian District, 100190, Beijing, PR China; Departamento de Ecología y Evolución, Facultad de Ciencias, Universidad de la República, CP: 11400 Montevideo, Uruguay.
authors.forename: Ivan
authors.initials: I
authors.lastname: González-Bergonzoni
authors.affiliation: Department of Entomology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Entomology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, PR China; Center for Eco-environmental Sciences Research, Nanjing Hydraulic Research Institute, Nanjing, 210024, Jiangsu, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Bioscience and Arctic Research Centre, Aarhus University, Central Jutland 8000, Denmark; Sino-Danish Centre for Education and Research, University of Chinese Academy of Science, Haidian District, 100190, Beijing, PR China.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Vidal
authors.affiliation: Department of Bioscience and Arctic Research Centre, Aarhus University, Central Jutland 8000, Denmark; Sino-Danish Centre for Education and Research, University of Chinese Academy of Science, Haidian District, 100190, Beijing, PR China.
authors.forename: Erik
authors.initials: E
authors.lastname: Jeppesen
authors.affiliation: Sino-Danish Centre for Education and Research, University of Chinese Academy of Science, Haidian District, 100190, Beijing, PR China; Nanjing Institute for Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, Jiangsu, PR China.
authors.forename: Zhengwen
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Entomology, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, PR China. Electronic address: wangbeixin@njau.edu.cn.
authors.forename: Beixin
authors.initials: B
authors.lastname: Wang
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D044822:Biodiversity; D002681:China; D004784:Environmental Monitoring; D007448:Invertebrates; D045483:Rivers
keywords: Benthic macroinvertebrates; Bioassessment; Biological traits; Functional diversity; Land use