Spatio-temporal resource use at a microhabitat scale in an amphibian community at a pond in Mediterranean Central Italy

The micro-habitat use in relation to the spatial and temporal context was studied in a six-species-community of amphibians in a Mediterranean pond in Central Italy. Several concurrent sets of statistical analyses, including univariate, multivariate and null model simulations, were used in order to interpret the community structure. In terms of micro-habitat selection, the newt species Tr i t u rus carnifex and T. vulgaris used primarily the aquatic habitats for most of the time spent in the pond, whereas the anuran species (Bufo bufo, Hyla intermedia, Rana dalmatina and the green frogs) used mainly the terrestrial micro-habitats adjacent to the pond except during the reproductive period when they used also the aquatic micro-habitats. A PCA analysis classifying the amphibian species on the basis of their spatio-temporal habitat use put each species in a separate part of the multidimensional space, whereas another set of PCA analysis revealed that, on the basis of the use of the aquatic micro-habitats, there were four ‘groups’: a) Hyla intermedia and the green frogs; b) Bufo bufo and Rana dalmatina; c) Tr i t u ru s vulgaris; d) Triturus carnifex. Some species used the micro-habitats types in relation to their relative availability in the field, whereas other were clearly selective in their requirements. Null model analyses based on Monte Carlo permutations of overlap values (RA2 and RA3 algorithms)showed that the various species were arranged in the micro-habitat scale in a non-random way. The general implications of these results are discussed.