Turnover Drives High Benthic Macroinvertebrates’ Beta Diversity in a Tropical Karstic Lake District

Abstract

Beta diversity is useful to explain community assembly across landscapes with spatial variation. Its turnover and nestedness components help explain how beta diversity is structured across environmental and spatial gradients. Assessing beta diversity in freshwater ecosystems is essential to conservation, as it reveals the mechanisms that maintain regional diversity. Nonetheless, so far, no studies have examined the beta diversity patterns of benthic macroinvertebrates in tropical lakes. We aimed to examine the beta diversity patterns and components of the deep benthic macroinvertebrate communities of tropical Lakes of Montebello, Mexico, along spatial and environmental gradients. We used presence/absence data of deep benthic macroinvertebrates from 13 lakes distributed along environmental and spatial gradients. We calculated beta diversity indices and correlated them to each lake’s environmental and spatial variables. The macroinvertebrate communities of the Lakes of Montebello showed high beta diversity driven by a turnover pattern that emphasises the importance of regional-scale conservation efforts. Short distances between lakes and high environmental heterogeneity promoted species turnover, resulting in a great singularity level among lakes. We did not find significant correlations between the beta diversity components and the environmental variables, suggesting a random distribution given by the species’ high dispersal capacity in a reduced spatial extent across the lake district.

Microcrustacean (Cladocera and Copepoda) Assemblages of a Tropical Karst Lake District

“…Most copepods belong to the genera Mastigodiaptomus, Leptodiaptomus, Mesocyclops, and Thermocyclops, all with greater diversity in tropical areas [28,58,59]. Recently, [12] explained that the closeness between lakes and the high environmental heterogeneity promoted species turnover, resulting in the large regional diversity but great singularity level among the benthic macroinvertebrates of the "Lagunas de Montebello" National Park lakes. The same large regional diversity but great singularity in these lakes have been reported for the zooplankton and benthic macroinvertebrates communities [10,11,60].…”

“…This unicity justifies its designation as a natural protected area by presidential decree in 1959, RAMSAR Site in 2003, and Biosphere Reserve MAB-UNESCO in 2009. Previous studies [10,11] suggested a great regional (i.e., the whole lake district) aquatic biodiversity but a large individual singularity (i.e., very few taxa present in more than a lake), stressing the fragility of these aquatic ecosystems [12]. Belonging to the same lake district and located close to each other, sharing the same climate, and with similar physical and chemical characteristics, it is unusual that these lakes share a small number of common species of the few biological communities investigated so far (rotifers, benthic macroinvertebrates).…”