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.

Contribution of nucleation techniques to plant establishment in restoration projects: an integrative review and meta‐analysis

“…The most popular active restoration strategy in forest vegetation is the establishment of plantations to increase canopy cover and trigger habitat succession (Benayas et al 2008), although this practice sometimes shows low efficiency in restoring biodiversity (Zahawi et al 2013). On the other hand, restoration practices that aim to improve the arrival and establishment of colonizing species, such as nucleation techniques, induce natural regeneration and accelerate natural succession from a nucleus that differs from the surrounding matrix (Fragoso et al 2020). The initial guiding concept of these nucleation techniques is to enhance habitats using methods that improve environmental conditions and facilitate the input of other species, thereby restoring ecological niches and ecosystem processes (Bulleri et al 2016).…”

“…In highly degraded soils, for instance, nucleation practices promote the entrance of species that otherwise would not establish due to an unfavorable environment (Brooks et al 2009; Fragoso et al 2020). Even when abandoned fields or degraded areas are surrounded by native vegetation, which might function as seed source, only a small subset of species disperses to the altered environments, and wind‐dispersed species are usually overrepresented (Vicente et al 2010; Zwiener et al 2014; Fragoso et al 2020).…”

“…In highly degraded soils, for instance, nucleation practices promote the entrance of species that otherwise would not establish due to an unfavorable environment (Brooks et al 2009; Fragoso et al 2020). Even when abandoned fields or degraded areas are surrounded by native vegetation, which might function as seed source, only a small subset of species disperses to the altered environments, and wind‐dispersed species are usually overrepresented (Vicente et al 2010; Zwiener et al 2014; Fragoso et al 2020). For more than 20 years, planting islands ( nuclei ) have been used to facilitate restoration, guided by the idea of employing trees as catalysts and thus enabling vegetation establishment with the subsequent entry of animals (Benayas et al 2008; Corbin & Holl 2012; Bechara et al 2016).…”