Anthropogenic pressure explains variations in the biodiversity of pond communities along environmental gradients: a case study in south-eastern Serbia

While several studies have tested the effects of anthropogenic factors on specific taxa in ponds, the simultaneous effects of the overall anthropogenic pressure along the environmental gradient on the diversity of different groups of pond communities remain unknown. In this study, we evaluated the simultaneous effects of the overall intensity of human impact and characteristics of natural pond variability on the diversity and density of macrophytes, benthic and epiphytic macroinvertebrates, and fish community and water chemistry in pond ecosystems. We found a reduction in the diversity and density of macrophytes and in the diversity of epiphytic macroinvertebrates with an increased human pressure. The effects of the intensity of human impact on the diversity of epiphytic macroinvertebrates were mediated via changes in macrophyte diversity. Benthic macroinvertebrates were not affected by an increase in the intensity of human pressure. Fish community responded to the increased human pressure with shifts in abundance through the predominance of invasive species. Natural pond variability properties affected the pond communities and water chemistry in the majority of cases. Our results conclude that for understanding the effects of human activity on pond biodiversity, integrating the simultaneous effects of multiple anthropogenic and abiotic factors in ponds is desirable.