Thu, Aug 05, 2021:On Demand
Background/Question/Methods
Nucleation by galleries represents a low cost method for restoration of degraded areas. However, its implementation still needs studies. The method consists of microhabitats formation in nuclei assembled with organic material, such as branches and other woody residues. By gathering shelter and food, such galleries will attract seed dispersing animals, favoring restoration. Our objective was to evaluate the galleries in the attraction of small mammals. We worked in a degraded area due to borrowing soil for the construction of the Emborcação hydroelectric plant – CEMIG, in the municipality of Catalão, in Goiás State, Brazil. We set up 75m length transects, along which we delimited six sampling points (plots) of 2m² every 15 meters, for sampling the fauna. Six of these transects were assembled in pairs, keeping a distance of 50m between them. In the pair, one transect contained galleries of 1m³ in each plot, while in the other transect, the plots did not contained galleries. We also set up 3 transects, without galleries, inside the remaining forest, our reference area. For sampling, we used 2 Sherman traps with baits containing a mixture of peanuts, sardines, cornmeal and bananas in all plots. (Approved study: ICMBIO 65066-3 and Ethics Committee 3197261218). We tested whether abundance and richness of small mammals were influenced by the type of habitat, considering: degraded area with galleries, without galleries and reference area. We analyzed using Generalized Linear Models (GLMs) with quasipoisson error distribution (software R 3.4.3 Development Core Team 2017).
Results/Conclusions Over 8 months, we obtained a total of 76 individuals, corresponding to seven species, including rodents and marsupials. Habitat type influenced richness (F=6.59; p<0.05) and abundance (F=10.81; p<0.05) of small mammals. Reference area showed greater richness and abundance, when compared to degraded areas with and without galleries. Transects with and without galleries in the degraded area showed no difference in the community structure. Despite the proximity to forest areas, our galleries were not efficient in attracting small mammals. Evaluating in the light of the islands biogeography, the galleries would be like islands in the middle of the degraded area. However, in this case they consisted of very small nuclei to provide microclimate and resources beyond of that provided by the control area. Larger nuclei would have greater species richness and abundance and would suffer less edge effect. It is necessary to define a standard for the size of the galleries.
Results/Conclusions Over 8 months, we obtained a total of 76 individuals, corresponding to seven species, including rodents and marsupials. Habitat type influenced richness (F=6.59; p<0.05) and abundance (F=10.81; p<0.05) of small mammals. Reference area showed greater richness and abundance, when compared to degraded areas with and without galleries. Transects with and without galleries in the degraded area showed no difference in the community structure. Despite the proximity to forest areas, our galleries were not efficient in attracting small mammals. Evaluating in the light of the islands biogeography, the galleries would be like islands in the middle of the degraded area. However, in this case they consisted of very small nuclei to provide microclimate and resources beyond of that provided by the control area. Larger nuclei would have greater species richness and abundance and would suffer less edge effect. It is necessary to define a standard for the size of the galleries.