Water bears in the Anthropocene: a comparison of urban and woodland tardigrade (Phylum Tardigrada) communities in Southwestern Louisiana, USA

Humans have had such a profound effect on global ecosystems, including biodiversity, that Anthropocene is being increasingly used as a chronological term to mark the period of greatest human impact. No areas show the effect of human impact on the environment more than cities, which often have novel combinations of species in unique communities. Tardigrades (Phylum Tardigrada) have often been collected in cities, but studies dedicated to urban tardigrade biodiversity are few, and those comparing urban diversity with nearby rural or natural sites even fewer. In this paper we compare the diversity and abundance of tardigrade species in Lake Charles with a nearby forested nonurban site, Sam Houston Jones State Park (SHJSP). Although tardigrade density did not differ significantly between Lake Charles and SHJSP, species richness and diversity were greater in SHJSP (17 species, H1=3.01) than in Lake Charles (8 species, H1=1.30). All but one species found in Lake Charles also occurred in SHJSP. The number of species found in Lake Charles lies within the range (5-10) found in previous urban surveys. All tardigrade studies comparing urban with nearby nonurban habitats have found lower species richness in cities.