Avaluació de la gestió forestal postincendi del Vilar de Blanes: anàlisi de la diversitat i la composició de la comunitat de formícids

Abstract

The increase in biofuel demand in recent decades is one of the main reasons why post-fire management is based on the mass extraction of the affected biomass. This invasive management has a direct influence on the biodiversity of the ecosystem and on the community structures. The epigeous arthropods of the Formicidae family are essential elements of the forest and are usually used as bioindicators because of their high sensibility to environmental changes and to allow the interpretation of the changes caused by a disturbance. This bioindicator capacity is used to evaluate the impact of the fire occurred in summer 2016 in the area of Vilar de Blanes area of summer 2016 and the subsequent forest management. The differences between plots managed with the “Fitxa de Bones Pràctiques” (Good Practice Sheets) of the Anifog project and plots without intervention were evaluated, as well as the differences between three microhabitats: regrowth of Viburnum tinus or Arbutus unedo, empty soil and pile of burnt branches. An analysis of the sampled species abundance in each of the microhabitats was carried out and no significant differences were observed between treatments. In contrast, the diversity indices did define a greater diversity in the microhabitats with management, being the microhabitat of Regrowth the most representative. The distribution patterns of the community species in the different microhabitats can be explained through their ecological action and their diet. Thus, predator or scavenger species turned out to be more explanatory for the Regrowth and Pile habitats, while the omnivorous diet did not show significant preferences. In addition, a comparative analysis between this fall sampling and a spring sampling was performed to see if the management is favorable over time. Although the similarity studies showed clear differences between seasons, this dissimilarity can’t be attributed to the performed management, since the seasonality modifies the activity patterns of the species of the community. Therefore, in order to assess the efficiency of the post-fire management, it is recommended to do annual samplings in order to monitor the evolution of this type of management