Herbaceous cover enhances the squamate reptile community in woody crops

Abstract

The intensification of agriculture entails the simplification and homogenisation of the landscape, which has serious negative impacts on animal biodiversity. Herbaceous ground cover in olive groves creates heterogeneous patchworks that differ as regards how intensively farmed olive groves are structured and composed, which may lead to a decrease in this loss of biodiversity. Reptiles rapidly respond to changes in vegetation and other habitat disturbances, in spite of which, this taxa has received very little attention with regard to their vulnerability to agriculture systems. In this study, we investigated the response of a squamate reptile assemblage to different management systems in olive groves. Reptile communities were recorded in areas with three types of olive grove management systems: bare ground, natural cover crop, and monospecific cover crop. We further compared habitat structure and vegetation richness in the study area in order to verify if management systems have an impact on the frequency of occurrence and diversity of squamate reptiles species within olive groves. The community composition of reptiles differed among the three management systems, although this was modulated by the age of the olive trees. Our results show that the squamate reptile communities were more restricted in areas of intense management (bare ground) than in those with cover crops. When herbaceous covers existed, natural ground cover harboured a more diverse community. Our data suggest that while monospecific cover crops improve the frequency of occurrence of reptiles, species richness does not increase; however, more heterogeneous herbaceous ground cover (which, for instance, contain more species and are more similar to natural vegetation) would be a better solution regarding the promotion of diversity in reptile assemblages in agricultural landscapes. Finally our results may be used to improve the habitat quality of squamate reptile communities in similar woody crops like vineyards or orchards, where cover crops are beginning to be implemented.