Changes to anuran diversity following forest replacement by tree plantations in the southern Atlantic forest of Argentina

GANGENOVA, E.; MARANGONI, F.; MARTI, D.

Posadas

Jornada; IX Jornadas Científico Tecnológicas; 2015

UNaM

The replacement of native forests by high-density tree plantations affects the richness and composition of animalcommunities through the modification of the resource availability, hydrological regimes, nutrient cycles and soilstructure. Previous studies have been conducted mainly on birds and mammals, whereas few have explored theresponse of anurans, a taxon considered at risk and in steep decline. With this study we aimed to evaluatechanges in anuran diversity associated with native forest replacement by pine plantations (Pinus taeda) in thesouthern Atlantic forest of Argentina, a highly diverse and threatened ecosystem. Additionally, we intended toexplore the role of the micro-habitat (terrestrial, aquatic) in the response. We characterized vegetation andhabitat structure and sampled anurans in terrestrial and aquatic micro-habitats in the native forest and pineplantations monthly over two consecutive years (2012?2014), using three complementary techniques (pitfalltraps, audio strip transects and larval sampling). A total of 964 individuals of 21 species were captured:Physalaemus cuvieri, Odontophrynus americanus and Elachistocleis bicolor were the most abundant species.Replacement of the structurally complex native forest by extremely simplified monoculture tree plantationsinfluenced the patterns of anuran alpha and beta diversity. However, these changes were micro-habitat-dependent:changes in anuran diversity in the terrestrial habitat were explained by species loss, while those in theaquatic habitat were explained by both species loss and turnover. The arboreal species of the family Hylidae(eight) were found absent from tree plantations. Both the hydroperiod instability of the water bodies and thesimplified vegetation structure of the tree plantations are probably limiting the suitability for both reproductionand larval development of some specialist species. The native vegetation surrounding the water bodies in the treeplantations constitutes a central element to maintain anuran diversity, through increasing the hydroperiod andproviding a habitat for species reproduction in the southern Atlantic forest and to facilitate the movement ofindividuals among native forest remnants.