Glyphosate effects on seed bank and vegetation composition of temperate grasslands

摘要: Questions Intensification of livestock production has led to the increasing input agrochemicals, mostly herbicides, in natural and semi-natural grasslands. Glyphosate application shifts vegetation composition grasslands Flooding Pampa region. Consequently, we asked two questions: (1) does glyphosate affect size, diversity seed bank these grasslands; (2) what extent determine grassland communities affected by application? Location Temperate-humid region, Buenos Aires, Argentina. Method We studied paddocks dominated native on a commercial farm. is usually applied late summer promote winter annual grasses We chose three that had never been exposed any herbicide treated with during previous 5 years. extracted soil cores evaluate from 2007 2009 recorded basal cover above-ground 2008 2010 upper lower position each paddock. Results Glyphosate treatment caused dramatic shift composition, so densities cool-season increased while cool warm-season perennial grasses, sedges, legumes dicotyledonous herbs decreased. Richness were dominance was higher under treatment. Similarity between floristic glyphosate-treated position. Strong correspondences species cool- untreated found. Conclusions Because changes response involved local extinction several species, community restoration would depend mainly propagule dispersal adjacent areas. Our results raise awareness risks widespread for biodiversity conservation last habitats Pampas