Feral horses dung piles as potential invasion windows for alien plant species in natural grasslands

摘要: Small scale disturbances could act as patches that provide sites for the colonization of competitively inferior species, promoting establishment non-native species in some cases. We analyzed vegetation associated with feral horse dung piles montane pampas grasslands Mid-East Argentina and described changes following their abandonment, evaluating whether invasion windows, allowing entrance alien plant species. estimated portion study area directly covered by manure height was used to estimate time elapsed after abandonment each pile. Vegetation replacement on different ages assessed compared grassland controls using discriminant analysis. regression analysis look cover, richness, diversity evenness response (age) piles, principal component analyses (PCA) identify groups plants successional stages. cover one-way ANOVA. On average, 2.5% dung. Total increased were abandoned. Characteristic initial, middle last phases studied succession. significantly differed from two consistently piles: invasive Red Star Thistle, Centaurea calcitrapa, a native grazing-intolerant grass, Nassella clarazii. Non-native also higher than control plots. Dung significant our site, produce are eventually colonize more pristine areas vicinity. other hand, they might represent refuges palatable since horses seem avoid them grazing.