Distribution and diversity of meiofauna along an aquatic-terrestrial moss ecotone

Abstract

Summary This study provides first insights into the moss-dwelling meio-invertebrate community inhabiting mosses collected from underwater, splash-water and adjacent terrestrial habitats along a Swedish lake. Additionally, changes in both species and functional diversity of the nematode community were followed. Total meio-invertebrate mean densities and biomass peaked at 10 644.2 ± 2391.8 individuals (g dry weight (DW) moss)−1 and 14 199.3 ± 5037.3 μg DW (g DW moss)−1 underwater, 1 m away from the shoreline, where the community was strongly dominated by rotifers, followed by nematodes. Total invertebrate biomass in terrestrial mosses was much lower, indicative of a significantly higher carrying capacity of moss patches in aquatic environments, which provide a high level of resource turnover as well as a buffer against desiccation and extreme temperature fluctuations. We found a total of 74 nematode species and maximum diversity was attained 1 m away from the shoreline and at the splash-water zone. The underwater mosses at the shoreline thus housed the most diverse and abundant assemblages of meio-invertebrates, suggesting they may play an important ecological role at the land-water interface. Evidenced by the multiple shifts in dominance, our study clearly showed that feeding types differed between habitats. The taxonomic and functional segregation of the nematode community along the ecotone further indicated that the composition of nematode species assemblages has the potential to mirror the ecological changes of the study site, even at small scales.