Canvis en la comunitat de coleòpters de vegetació a causa d'un incendi forestal al Parc Natural de Sant Llorenç del Munt i l'Obac

Abstract

In the Mediterranean Basin, fires have played a key role in the landscape structure and in the composition of organism communities. In the future, it is expected that this disturbance increases in terms of extension and frequency, thus affecting the maintenance of biodiversity in the Mediterranean natural reserves. In this work, we have analyzed the response of vegetation beetles after a wildfire occurred on August 2003 in the Parc Natural de Sant Llorenç del Munt i lObac. In the spring of 2007, a sampling program with sweep net was conducted in a total of 24 sampling stations, which included a control area (not burnt) and four areas with different post-fire management practices. Alpha (Margalef index, uniformity and Simpson) and gamma diversity measures (total number of species in the study area), and multivariate analysis (Principal Component Analysis) were calculated using the abundance of species of beetles at sampling stations. A total of 876 specimens of beetles belonging to 75 species were collected. The results showed a general increase in abundance and species richness in the burned areas compared to the unburned forest, as well as an increase of gamma diversity. The commonest species in control forested sites became scarce or extinct in burned sites. Furthermore, we observed many exclusive species from a single area (33). The increase in the total number of species (gamma diversity) and the high number of exclusive species could be caused by habitat heterogeneity (forest versus open-areas) and also by differences among burned sites due to the application of several post-fire management. Our study supports the general idea that landscape heterogeneity may cause high levels of biodiversity in Mediterranean ecosystems.