Impacts of livestock and pasture management on forest regeneration in Araucaria Forest remnants

Abstract

In some regions of Southern Brazil, historic silvopastoral systems, known as caívas in Santa Catarina State and faxinais in Paraná State, are used in remnants of Araucaria Forest. In these systems, the herbaceous stratum of the forest is composed of natural pasture on which animals graze. In order to better understand the impact of caívas on the conservation of the Araucaria Forest, the effects of different intensities of pasture management, mowing practices, and cattle grazing on natural regeneration were assessed. The experiment was carried out in eight caívas from 2015 to 2016, during which the forest regeneration was monitored every six months. Throughout the study period, 48 tree species that are characteristic of the Araucaria Forest were identified. In all evaluated scenarios, the regeneration of tree species was present, dynamic, and continuous in the caívas. The intensity of pasture use did not affect the indicators of diversity, species richness, and regeneration density. However, there was limited similarity among caívas with the same type of pasture management. Mowing had the greatest impact on regeneration, with a marked reduction in the density of regenerants, although it did not affect species richness. Given the abundance of species in the regeneration, including many species typical of advanced forest succession, it is possible to confirm that these systems present high levels of resilience with respect to the conservation of biodiversity, despite the occurrence of livestock grazing for generations. The results also indicate that it is possible to successfully implement strategies for pasture intensification in caívas. However, this practice must be associated with preservation strategies in forest areas that are more fragile and diverse, in order to ensure the system is sustainable across all dimensions.

Keywords:
Caíva; Silvopastoral system; Axonopus catharinensis; Agroforestry; Cattle grazing