Avaliação do impacto da frequência de queimadas na diversidade de pequenos mamíferos no Parque Nacional do Kruger, África do Sul

Abstract

In savanna ecosystems, fire is a natural and important disturbance in the maintenance and conservation of ecosystems. However, several studies carried out in savanna ecosystems show that knowledge gaps still prevail on the impact of the frequency of fires on the elements of biodiversity, particularly on the diversity of small mammals. The study was carried out in the regions of Punda Maria and Vlaktplaas, in the north of the Kruger National Park, South Africa. The aim of the study was to assess the impact of the frequency of fires on the diversity and abundance of small mammals and on different types of soil. and to assess the association between habitat variables and capture success, an indicator of small mammal abundance. Areas under high and low frequency of burning were identified in granitic and basaltic soils. In each soil type, six replicates were established, three in the areas with low frequency and the other three in the areas with high frequency of fires, totaling 12 replicates in both types of soils. In each replica, a Pitfall trap of about 70m in length, 20 Sherman cages and four Tomahawks cages were placed, with an effort of 18 traps per night, 60 traps per night and 12 traps per night respectively, with the exception of soils. basaltics where 40 traps per night were used for Sherman cages. For the survey of the habitat variables (grass biomass, distance to the tuff and ecological condition of the pasture), two contiguous transects of 160m in length were established, where with the pasture measuring disc 100 readings were made and at separate distances of 3 in 3 meters the distance to the tuff was measured. For the calculation of species diversity, similarity between areas with granitic and basaltic soils and in different firing frequencies, Microsoft Excel 2010 software was used and the statistical program Stata10 was used to analyze the correlation of person between the success of capture and the habitats. Granitic soils showed a greater number of species, diversity and abundance than basaltic soils. The areas under high fires frequencies presented a greater number of species, diversity and abundance than the areas under low fires frequencies. High firing frequencies have positive effects on the richness, diversity and abundance of small mammals in the KNP. The capture success was not significantly associated with the habitat variables tested in the present study (grass biomass, distance to the tuff and ecological condition of the pasture). (TRADUÇÃO NOSSA)