Introduced goats reduce diversity and biomass of herbs inCaatinga

Herbivores are considered important drivers of vegetation shifts in rangelands worldwide. In the BrazilianCaatinga years in 16 paired exclosure versus free-access plots. Exclosure of goats caused a small but significant increase in the species diversity and above-ground biomass of herbs that varied strongly with time. Taxonomic dissimilarity between exclosure and free-access was small and due to the turnover of a few species, however, tended to increase with time. Environmental co-variables, such as rainfall, forest cover, and grazing pressure were also important and have varying effects on herbaceous communities, adding complexity to the processes of species assembly ofCaatingarangelands. Management of grazed ecosystems must take into account that goats can shift plant species composition and diversity with potential cascading effects on ecosystem functions.

Automated summary

The presence of herbivores, specifically goats, can significantly impact the species diversity and above-ground biomass of herbaceous vegetation in the Caatinga region of Brazil. The effects of goat exclosures on vegetation diversity and biomass vary over time, with environmental factors such as rainfall, forest cover, and grazing pressure also playing important roles. This highlights the complexity of species assembly processes in Caatinga rangelands and the potential cascading effects on ecosystem functions resulting from changes in plant species composition and diversity caused by goat grazing.