Spatial Variations in Water Beetle Communities in Arid and Semi-Arid Patagonian Wetlands and Their Value as Environmental Indicators

EPELE, L.B. & ARCHANGELSKY, M.

ZOOLOGICAL STUDIES

ACAD SINICA INST ZOOLOGY

Lugar: Taiwan; Año: 2012 vol. 51 p. 1418 - 1431

1021-5506

Spatial variations in water beetle communities in arid andsemi-arid Patagonian wetlands and their value as environmental indicators. Zoological Studies 51(8): 1418-1431. To evaluate spatial variations in aquatic beetle assemblages, 26 Patagonian ponds were sampled duringlate spring (Dec.). The hydroperiod, hydrology, abiotic features, precipitation, aridity, and aquatic plant richnessof the study sites differed. Fifteen physicochemical features were measured, and aquatic plants were collectedto determine taxonomic richness. Sampling of the 26 ponds produced 21 aquatic beetle taxa in 6 families. Allaquatic beetles (adults and larvae) were assigned to functional feeding groups. A canonical correspondenceanalysis (CCA) was run to assess relationships between aquatic beetle assemblages and environmentalvariables. Of the variance in aquatic beetle taxa abundances, 23% was accounted for by the 1st 3 ordinationaxes. Moreover, the 1st 2 canonical axes respectively accounted for 38.2% and 28.4% of the variationsattributable to environmental variables (i.e., annual precipitation, elevation, pond area, aquatic plant richness,pH, and conductivity), with conductivity and elevation being the most important. A parsimony analysis wasperformed to establish which species could define and/or group some of the communities (with sampling sitestreated as taxa and species treated as characters). Results of the parsimony analysis suggested that sometaxa (Haliplus subseriatus, Gymnochthebius sp., Enochrus darwini, Cyphon sp., Luchoelmis sp., and Rhantusvalidus) were useful in defining some ponds or groups of ponds. These species can be used as indicators sincebeetle distributions are not considered to randomly occur. Our findings show that aquatic beetle assemblagescan be utilized for wetland conservation planning since in arid and semiarid Patagonia, they are important aswater reservoirs and for cattle rearing.