Dissertação
Cultivo de eucalyptus reduz a diversidade da herpetofauna em área de campo no sul do Brasil
Fecha
2014-02-19Registro en:
ALVES, Suélen da Silva. EUCALYPTUS FORESTATION REDUCES THE HERPETOFAUNA
DIVERSITY OF GRASSLANDS INSOUTHERN BRAZIL. 2014. 75 f. Dissertação (Mestrado em Ciencias Biológicas) - Universidade Federal de Santa Maria, Santa Maria, 2014.
Autor
Alves, Suélen da Silva
Institución
Resumen
The expansion of forestation on grassland ecosystems has dramatically changed the landscape, as well
as affected the biodiversity and the sustainability of these ecosystems around the world. Grasslands of
southern South America hold high diversity and several cases of endemism, but historically are
insufficiently protected in conservation units and experience drastic reduction due to cultivation of
exotic trees as eucalyptus, black wattle and pine. Grasslands of Pampa biome in Brazilian territory are
restricted to the state of Rio Grande do Sul, where recent estimates indicate that the grassyfields will
disappear within the next few decades if the current scenario of changes in the productive matrix is
maintained. In order to contribute with subsidies to conservation of grasslands ecosystems, the goal of
this Dissertation was to study the spatial patterns in the distribution of herpetofauna (i.e. amphibians and
reptiles), as well as environmental variables associated with native grasslands and eucalyptus plantation
in the Pampa biome, Rio Grande do Sul state, Brazil. Thus, native grasslands and eucalyptus crops were
characterized and compared regarding species richness, taxonomic composition, and abundance of
amphibians and reptiles, using pitfall traps during eight sampling months (September 2012 to April
2013). The communities of amphibians and reptiles studied responded negatively to the replacement of
native grasslands by arboreal crops because they were dominated by a few species in eucalyptus
cultivation . Through nesting analysis and similarity tests, we recorded that reptiles responded strongly
to habitat modification, since the community recorded in eucalypt was an impoverished subset of that
recorded in native pasture, being still dominated by species commonly abundant in degraded areas.
Amphibians responded strongly regarding species abundance and keenly to species richness, but did not
respond to the gradient regarding taxonomic composition of the community. The environmental
variables most strongly related to the pattern of segregation observed between native grasslands and
eucalyptus cultivation were the percentage of low cover vegetation on soil and brightness. Our results
indicate that eucalyptus forestation profoundly modify the structure of undergrowth vegetation, typical
of grassland ecosystems and essential to the biology of several habitat-specialist species, including rare
species. In this context, we emphasize that the habitat loss due to expanding forestation on grasslands
configures a serious threat to conservation of the herpetofauna of the Pampa biome. Such effects can be
minimized only after the adoption of specifically committed environmental policies to the conservation
of grasslands ecosystems, until now so neglected.