Dissimilarity in plant species diversity between salt marsh and neighbour environments decreases as environmental harshness increase
CANEPUCCIA, A.; PÉREZ, C. F.; FARINA, J. L.; ALEMANY, D.; IRIBARNE, O.
MARINE ECOLOGY PROGRESS SERIES
Lugar: Oldendorf/Luhe; Año: 2013 vol. 494 p. 135 - 148
How species similarity change between habitats along environmental gradients is still a central challenge in ecological studies. We assessed if marsh plant characteristics are associated with geographic changes in environmental conditions and if there are environmental factors associated with marsh-inland dissimilarity in species composition. Field samples of plant characteristics (cover, tallness, richness, and á diversity) and marsh-inland dissimilarity (â-diversity) in species composition were performed in six sites along the SW-Atlantic coastline. PERMANOVA analysis showed that plant assemblage changes among sites. Forward Stepwise Multiple Regression analysis showed that at lower marsh, plant cover increased in association with tidal range and decreased in association with salinity. At the high marsh, plant cover decreased in association with tidal range, salinity and with the minimum temperatures. Plant richness increased in association with tidal range and with marsh area; while á-diversity decreased in association with precipitation, and increased with salinity. Beta diversity, estimated by SIMPER analysis, increased in association with precipitation and decreased with salinity and daily thermal amplitude. We present evidence that there is an increase in á-diversity, but a decrease in â-diversity with environmental severity among co-specific marshes distributed along the SWA coast. Thus, communities developing in more benign conditions, regardless of their low local diversity, may increase the biodiversity at landscape scale by decreasing their similarities.