Factors determining variation in the distribution and abundance of macroinvertebrate communities in wetlands of north-eastern Algeria

Abstract

Benthic macroinvertebrates play an important role in inland waters, inhabiting diverse aquatic ecosystems where communities are structured in terms of space. Macroinvertebrates in some Mediterranean regions, such as North Africa, have not yet been well studied. For this reason, we proposed studying the community structure of water bodies located in north-eastern Algeria. To achieve this, we sampled 12 different types of water bodies: two dams, three rivers, and seven streams, from October 2020 to September 2021. Biotic and abiotic data were collected, and a redundancy analysis (RDA) was performed to determine the role of both types of variables in grouping the sites. Two types of null models were also considered: species co-occurrence and niche sharing to study the potential associations between the reported species, and maximum entropy analysis to model the distribution. The redundancy analysis showed that water velocity and conductivity were the main drivers of the macroinvertebrate community structure. The species co-occurrence results revealed that species associations were random, except for two sites: El Fadjoudj and Ain Ben Baida, which correspond to the Seybouse River. At the same time, there was no niche sharing, and consequently, no interspecific competition, except at the two sites: the Salah Salah stream and the Bouhamdane dam. MaxEnt revealed that the differences in the distribution of specific richness were massive, and that the Seybouse and El Fadjoudj rivers had the highest rate of specific richness. These results are similar to those of other studies of Algerian rivers and dams, as well as other similar water bodies in Mediterranean climates.