Geographical, environmental, and biotic constraints define the spatial distribution of <i>Diaphanosoma</i> species (Cladocera)

Abstract

Species distribution is a combination of ecological, historical, stochastic, and evolutionary mechanisms, and is a process that has been severely impacted by anthropogenic activities. Freshwater zooplankton is adequate to assess that combination because it groups cosmopolitan and endemic species. We hypothesized that the spatial distribution of Diaphanosoma species is defined by a complex interaction between factors such as spatial limitation, limitation of environmental conditions, and ecological conditions. We georeferenced the occurrence of Diaphanosoma in Brazil to study the potential distribution of the species, preference of ecoregions, environmental features associated with Diaphanosoma, and their co-occurring patterns. Five species of Diaphanosoma are widely distributed in Brazil. D. spinulosum and D. birgei were widely distributed while D. fluviatile and D. polyspina had a more restricted distribution. The occurrences of Diaphanosoma species were shown to have an association with factors such as the total concentrations of nitrogen and phosphorus, pH and, temperature, except in the case of the D. brevireme. Our results show that geographic, environmental, and biotic filters can drive the spatial distribution of species of the genus Diaphanosoma. Therefore, the distribution and spatial occurrence of these species depend on dispersal capacity and spatial restrictions, suitability of the abiotic environment, and ecological interactions.

Keywords

• environmental filters
• competition
• ecoregions
• congeneric species
• biogeography