Windows into the Recent Past: Simple Biotic Indices to Assess Hydrological Stability in Small, Isolated Ponds

Abstract

This article presents the four biotic indices used to assess the hydrological stability of small, fishless, lowland ponds in northern Poland’s post-glacial landscape. The assessment was based on the analyses of the relative abundance of selected macroinvertebrate taxa caught using standard and non-lethal methods. The indices were derived from a multi-year analysis of data on invertebrate composition, abiotic water parameters, and publicly available satellite data. This allowed for the reconstruction of hydrological stability, including fluctuations in water level and surface area, as well as the frequency of drying, in small water bodies in the 5–10 years before sampling. The numerical relationships between the parameters describing hydrological stability and the relative abundance of several invertebrate taxa were described. A multiple regression analysis showed that hydrological stability was generally more strongly related to faunal composition than the other abiotic parameters. The indices used in this study can be a useful tool, particularly in citizen science. It is important that their numerical bases can be easily modified depending on the local conditions.