Diversity of arthropods in farmed wetlands in the Gulf of Mexico coastal plain and effects of detrital subsidies

Abstract

Wetland acreage has declined continentally in the USA. With the loss of natural wetlands, farmed wetlands may be a surrogate for natural wetlands. Seasonally, flooded rice fields are commonly managed wetlands on the Gulf of Mexico Coastal Plain. This study had two objectives: (1) catalog arthropod diversity in rice fields; (2) investigate if detrital subsidies could elicit trophic cascades that reduce nuisance organisms. In 2013 and 2014, experimental rice plots were established, and detritus was applied to half of the plots in each year. Floating pitfall traps, aquatic D-net sweeping, Gee crawfish traps and root/sediment corers were used to sample for arthropods. Over the two growing seasons, 143 different species were sampled from 13 orders, totaling 49,251 individuals. Detrital subsidies neither elicited a detectable trophic cascade nor did they significantly alter the rice field arthropod community. Contrary to previous studies, results suggest that macroinvertebrate communities in farmed wetlands are resilient to alterations possibly due to the long-term agricultural use.