Contrasting effects of pine plantations on two skinks: Results from a large-scale 'natural experiment' in Australia

The conversion of agricultural land to forest plantations is a major driver of global land-use change, and considering that large portions of the planet are covered by forest plantations, understanding their impact on biodiversity is a research priority. The aim of our study was to quantify the long-term response of two lizard species to the transformation of the matrix surrounding remnant habitat patches (from agricultural land to pine plantations). We used a large-scale (115 sites), long-term (16 years) fully replicated and controlled landscape scale 'natural experiment' (the 'Nanangroe experiment', Australia) to compare the response of lizard populations to plantation establishment. The study entailed detailed surveys of reptiles in 50 eucalypt patches surrounded by maturing pine Pinus radiata plantations (treatments) and populations inhabiting 55 eucalypt patches surrounded by grazing land (controls). We found that the eastern three-toed earless skink Hemiergis talbingoensis was advantaged by the establishment of the pine plantations (increasing colonization of eucalypt patches embedded within plantations). In contrast, we found that the southern rainbow skink Carlia tetradactyla was negatively affected by surrounding areas of maturing plantations. Thus, our results show that plantations acted as a barrier for one species and increased connectivity for the other. We suggest that leaving areas of land devoid of pines between remnant eucalypt patches may enhance the connectivity for species that respond negatively to plantation establishment while maintaining the beneficial increase in connectivity for others.