Biodiv Sci ›› 2020, Vol. 28 ›› Issue (4): 504-514.DOI: 10.17520/biods.2019359

• Original Papers: Animal Diversity • Previous Articles     Next Articles

The spatial scale dependency of elevational patterns of taxonomic and functional diversity in aquatic insects in the Lancang River, Yunnan, China

Huiyu Wei,Kai Chen(),Beixin Wang   

  1. Laboratory of Insect Taxonomy & Aquatic Insects, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095
  • Received:2019-11-08 Accepted:2020-02-10 Online:2020-04-20 Published:2020-06-15
  • Contact: Kai Chen

Abstract:

Elevational patterns of taxonomic and functional diversity are important aspects of biodiversity maintenance and changes. However, the spatial scale dependency of elevational patterns on taxonomic and functional diversity of aquatic insect assemblages remains unclear. Using data collected from 149 stream sites along elevational gradients ranging between 500-3,900 m during 2013-2018 in the upper basin of Lancang River in Yunnan Province, China, we examined how elevational patterns of taxonomic and functional diversity of aquatic insect assemblages differed across local and regional scales among multiple elevational bands (i.e., 100, 150, 200, and 250 m). We used linear or quadratic regression models to explore the elevational patterns of taxonomic richness index, Simpson diversity index, evenness index, dendrogram- based functional diversity index (dbFD), Rao’s Quadratic index (RaoQ), and functional evenness index (FEve). At the local scale, taxonomic richness index and dbFD index show no significant elevational patterns; while Simpson diversity index, RaoQ index, evenness index, and FEve index show either U-shaped or monotonically decreasing trends along elevation gradients. At the regional scale with increasing elevation, taxonomic richness index decreases (NS) while dbFD index changes from U-shaped to a monotonically decreasing trend along the elevational gradient. Both Simpson diversity index and RaoQ index change from a significant U-shaped to no significant regional elevational patterns. Taxonomic evenness index and FEve index have no significant relationship with and significantly increased with regional elevations, respectively. Our results show that aquatic insect taxonomic and functional diversity are scale dependent across elevations. However, we observed a degree of consistency in elevational patterns for each taxonomic and functional diversity index across elevational bands at regional scales.

Key words: biodiversity, functional traits, elevation gradients, local scale, regional scale, stream, biogeography