Restoration of natural grasslands in the Pampa biome: short-term vegetation responses to selective chemical control of Eragrostis plana Nees

Resumo

The expansion of Eragrostis plana (Eragrostis plana Nees.) is one of the main threats to the ecological integrity of the native grasslands of the Pampa biome, damaging biodiversity and livestock productivity. This study evaluated the short-term effects of selective chemical control of this invasive species on two family livestock farms in southern Brazil, using the “Campo Limpo” equipment for localized application of glyphosate. Floristic and ground cover surveys were carried out before and after control, with statistical analysis of the data. Selective control significantly reduced the abundance of Eragrostis plana and ruderal species, promoting an increase in the dominance of forage grasses, especially the Paspalum genus. Although there was a reduction in total diversity and species richness, there was a qualitative improvement in the plant community, resulting in greater resistance to grazing disturbances and improved forage quality. The variables that demonstrate this increase in quality were the increase in the percentage of native field cover and the replacement of ruderal species with species of high forage value. Selective control proved to be effective, but requires periodic reapplications due to the species’ high potential for regrowth and re-establishment from the soil seed bank. The results indicate that selective chemical control is a promising tool for the productive recovery of degraded grasslands, as long as it is integrated with adaptive conservation strategies and the sustainable use of native grasslands.