Consequences of fire and cattle browsing on ground beetles (Coleoptera) in NW Patagonia

SASAL, YAMILA; RAFAELLE, ESTELA; ALEJANDRO GUSTAVO FARJI BRENER

ECOLOGICAL RESEARCH

SPRINGER TOKYO

Lugar: Tokyo; Año: 2015 vol. 30 p. 1015 - 1030

0912-3814

Understanding the responses of natural communitiesto disturbances remains a challenging task inecology. In northwestern Patagonia, the most importantdisturbances are fire and introduced ungulates. Althoughthese disturbances have been present in this regionsince late eighteen century, their effects onarthropods diversity have been poorly studied. Here, weexamined the short-term response of ground beetles(Coleoptera) to fire (burnt and unburnt) in browsedforests and to cattle browsing (cattle and no cattle) inpost-fire forests. We collected ground beetles with pitfalltraps and estimated beetle abundance, species richness,assemblage composition, abundance of trophic guildsand beetle characteristic species, and measured somehabitat parameters. We found that burnt browsed foresthad lower diversity and different assemblage compositionthan unburnt forest. Beetle abundance, assemblagecomposition and abundance of trophic guilds weresimilar in post-fire forests with and without cattlebrowsing. Conversely, beetle species richness was higherin cattle than in no cattle forests. Fire had a strongnegative effect on beetle diversity probably by its effectchanging habitat structure. Whereas fire had a homogenizinginfluence on beetle diversity with and withoutcattle, at small-spatial scales, browsing of cattle probablygenerate habitat heterogeneity enhancing beetlerichness. The implementation of policies aimed to reducethe risk of fire and to maintain low-moderate cattlepressure appears to be vital to conserve the beetleassemblage in the Patagonian region.