How vertebrate herbivores, especially nutria and wild boar, alter soil and plant characteristics over time was investigated during three summers in the Pearl River basin in southern Louisiana along the Gulf of Mexico (30Ãƒâ€šÃ‚Â° 11' N, 89Ãƒâ€šÃ‚Â° 35' W). Both nutria and wild boar graze year-round in these marshes, but typically stay in an area until most of the vegetation is utilized. Paired plots (fenced and unfenced) were established on ten grazed patches in May 1993. Above-ground biomass was measured, non-destructively every month. Soil accretion, elevation relative to a fixed point, and bulk density were measured every three months. Root biomass and zone thickness were measured every other months. Both bulk density and root growth were measured by taking soil cores and then replacing the cores with potting soil or sand, respectively. Species richness and light levels were also calculated before, during and after grazing. Sampling occurred from June 1993 until June 1995.
Effects of vertebrate herbivores on soil processes, plant biomass, litter accumulation and soil elevation changes in a coastal marsh