Environmental harshness decreases ant β-diversity between salt marsh and neighboring upland environments

JUAN L. FARINA; ALEJANDRO D. CANEPUCCIA; FABIANA CUEZZO; FERNANDO HIDALGO; OSCAR O. IRIBARNE

WETLANDS

SPRINGER

Lugar: Berlin; Año: 2016 vol. 36 p. 667 - 680

0277-5212

Understanding how wetland organisms interactwith neighbor habitats along environmental gradients is importantto recognize wetland integrity and its connectivity atlandscape-level.We evaluated whether assemblage characteristics(e.g. á-diversity) of marsh-ants are associated with geographicchanges in environmental conditions, and if these factorsare associated with marsh-upland dissimilarity in ant speciescomposition (â-diversity). Ant-samples were collectedboth in the marsh and in the neighboring upland habitat at 5-sites along the South-west Atlantic (SWA) coastline (36°S to40°S), encompassing two-distinct biogeographic regions.Generalized Linear Models showed that at the marsh scale,ant occurrence increased with maximum temperature andSpartina densiflora cover, but decreased with total-plant cover.Ant richness increased with salinity, S. densiflora cover andmarsh area; and ant á-diversity increased with S. densifloracover and decreased with total marsh plant cover and plantheight. Composition of ant assemblages differed between themarsh and the upland habitat depending on the site, and â-diversity decreased with precipitation, salinity, tidal amplitudeand á-diversity of the herbaceous stratum. Then, the abundanceand á-diversity of ants varied along SWA marshes inrelation to changes in local environmental factors and the regionallandscape. Moreover, changes in species characteristicsacross coastal-landscape seem to interact with environmentalgradients, resulting in reduced â-diversity values with increasingenvironmental harshness. Thus, our results suggest thatthe link of geographic changes in the physical environmentwith the changes in species traits drives the variation in marshuplanddissimilarity across the space