Impact of feral pig rooting in Tornquist Park, Buenos Aires, Argentina.

DIEGO NABAES; ALBERTO SCOROLLI

Mar de Plata

Conferencia; 2nd World Conference on Biological Invasions and Ecosystem Functioning; 2011

Grupo de Investigación y Educación en Temas Ambientales (GrIETA)

Feral pigs (Sus scrofa) are invasive mammals that cause serious environmental impact worldwide. In Argentina their geographic distribution is very wide and include many national parks and reserves. One of the most evident impacts is their rooting activity that expose soil and remove vegetation in searching for food. Tornquist Provincial Park protects one remnant of the hilly grassland ecosystems and include many animal and plant endemisms. Increasing feral pig activity was registered in the past 5 years. Our objective, in order to provide a baseline for monitoring, was to estimate the spatial extent of the rooting and to quantify the degree of revegetation and determine the dominant plant species in old rootings (non-fresh). From April to June 2011 we sampled 32 strip-transects 10m wide and 100m long located systematically in the grassland using a GPS. The total % of rooted area was 0,48% (153,12m2). All old rootings were at least partly revegetated, and the dominant plant species were Pavonia cymbalaria, Mimosa rocae, Oxalis spp., and a set of yet undetermined grass species. Fifty-nine (69,62%) of all old rootings (79) show more than 50% cover, while 23 (29,11%) present between 25-50% cover. Feral pig rooting impact on the grasslands of Tornquist Park are still incipient, but widely distributed. Vegetation recovery in old rootings was fast. Our results constitute the first baseline for future monitoring of the feral pig impact in the reserve and could improve their management.