Lizards along an agricultural land abandonment gradient in Pindos Mountains, Greece

Abstract

Agricultural land abandonment is recognized as one of the main environmental drivers in Southern Europe, affecting ecological communities. Lizards, as ectothermic species with low dispersal capacity, are particularly prone to the threats associated with land use changes. We investigated the effect of land abandonment on lizards in a remote mountainous area in Greece, using line transect sampling, in 20 randomly selected sites [1 km × 1 km], along a four grade abandonment gradient in terms of forest encroachment. We recorded four species: Algyroides nigropunctatus, Lacerta viridis/trilineata, Podarcis tauricus and Podarcis muralis, the latter being the most abundant. Our results did not provide evidence for a significant effect of forest encroachment or grazing on lizard diversity, given the dominance of P. muralis, the availability of all microhabitat types along the gradient and the low grazing intensity in the study area. Environmental parameters at the macrohabitat scale did not prove determinant for habitat variance, but microhabitat analysis showed a clear preference of P. muralis to bare ground. Despite the non-significant effects of land abandonment on lizard diversity, the dominance of P. muralis tends to indicate a lizard community shift towards species inhabiting forested habitats. The preservation of open microhabitats, such as bare land, is considered of great importance for promoting high levels of lizard diversity, as their loss would affect even species currently widespread in forested ecosystems. Low intensity grazing, as well as the enhancement of wild ungulate populations in abandoned areas, can contribute to halting forest encroachment and maintaining the required habitat heterogeneity.