Brushwood and artificial perch did not facilitate forest regeneration in Urochloa spp. grassland

Abstract

In Brazil, many pastures are formed by grasses of the genus Urochloa, which have recognized inhibitory effects on regeneration of native vegetation. Using facilitation practices for natural regeneration of these areas aims to promote forest restoration by creating safe sites in the seedbed. This study aimed to assess the efficiency of brushwood and artificial perch as techniques to improve native plant establishment in an area covered by the inhibitory grasses of Urochloa. Field work was conducted between February 2014 and February 2016, in an area of lowland Atlantic rainforest in Morretes-PR. A set of 12 8 m × 5 m plots were established, corresponding to three treatments and four replicates, organized according to randomized block and split-plot design. The treatments were: brushwood, brushwood + artificial perch and control treatment. Evaluations were conducted at 4, 8, 12, 18 and 24 months after the experiment was installed by counting and identifying regenerating woody species and visually estimating cover percentage of herbs and subshrubs species. Brushwood treatments with and without perch initially reduced Urochloa grasses; however, over time the initial effects ceased due to the rapid growth of grass at plot edges. Likewise, perches in this treatment did not increase native/woody species. We concluded that the ecological restoration of Urochloa pastures requires additional measures to control grasses and increase local resilience in order to improve the seedbed.