Climate-associated variation in the drivers of benthic macroinvertebrate species-area relationships across shallow freshwater lakes

The island species-area relationship (ISAR) describes how species richness increases with increasing area of a given island or island-like habitat, such as freshwater lakes. While the ISAR is one of the most common phenomena observed in ecology, there is variation in both the form of the relationship and its underlying mechanisms.
We compiled a global dataset of benthic macroinvertebrates from 524 shallow freshwater lakes, ranging from 1 to 293300 ha in area. We used individual-based rarefaction to determine the degree to which ISAR was influenced by mechanisms other than passive sampling (larger islands passively sample more individuals from the regional pool and, therefore, have more species than smaller islands), which would bias results away from expected relationships between rarefied species richness (and other measures that capture relative abundances) and lake area. We also examined how climate may alter the shape of the ISARs.
We found that both rarefied species richness (the ...