Detecção de mamíferos não voadores em micro-habitats distintos de área reflorestada

Abstract

Studies on variations in mammalian community in relation to the vegetation structure show that richness and abundance of species vary with vegetation quality. However, the knowledge about the response of mammal species in reforested environments is incipient. I aimed to verify whether micro-habitats composed of distinct complexities influence the detection and counting of non-flying mammals in a reforested protected area. Additionally, I tested the hypothesis that there would be an increase in species richness with the increase in micro-habitat complexity. The study was carried out at the Santa Helena Relevant Ecological Interest Area (ARIE-SH), a 1,400 ha remnant that underwent clear cutting and, after filling of the Itaipu Lake, was reforested with exotic and native species from the 1980s onwards. ARIE-SH is located at 24° 50'20 "S, 54°21'37" W on the shores of Itaipu Lake and is located close to the urban area of the municipality of Santa Helena, western Paraná, southern Brazil. To determine the complexity of micro-habitats, I took measurements on 10 x 10 m plots in three microhabitats. Within the plots I determined: the predominant tree species, the number of tree individuals, the number of tree species, the basal volume of trees, the density of trees, the height of trees, Shannon's diversity index, the presence of lianas, the percentage of canopy openness and litter biomass. I also gathered temperature and precipitation data. Between August 2020 and January 2021, I carried out inventories in three micro-habitats: low predominance density, absence of understory and high litter biomass (micro-habitat 1), high density of independent, developed understory and intermediate biomass litter (micro-habitat 2) and intermediate density, well-developed understory and intermediate litter biomass (micro-habitat 3). For the inventories I used (1) pitfalls (3,696 hours) and (2) linear transects (40 hours), in which species were identified visually (including traces) and / or aurally. Four species were captured in pitfalls and five species were observed during transects, for a total of seven species in the three micro-habitats. Micro-habitat 3 had greater species richness (n=5), but not greater complexity. The probability of trapping was low (0.5%) and driven by the litter, while the probability of observations was higher (4.8%) and driven by the maximum temperature and litter. For both methodologies, the probability of capture and observing mammals was 10.3%, also driven by the litter biomass. The capture count was influenced by the maximum and minimum temperatures, while the counts during the transects were driven by the litter. For both methodologies, the counts were influenced by three covariables: minimum temperature, litter and canopy openness. The species were habitat generalists and the species richness per micro-habitat, in ARIE-SH, had no relation to their complexity. The micro-habitat reforested with Syzygium cumini (L.) Skeels, an exotic allelopathic species, had no understory and obtained the least less richness and complexity, meaning that, to maintain the biodiversity of the Atlantic Forest, future reforestation must not consider this species. Keywords: Habitat complexity. Reforestation. Restoration. Seasonal Semideciduous Forest.