Dissertação
Distribuição espaço-temporal de comunidades de girinos (Amphibia: Anura) no cerrado sul-mato-grossense
Fecha
2011-02-25Registro en:
AMARANTE, Débora Delevati do. SPATIO-TEMPORAL DISTRIBUTION OF TADPOLE COMMUNITIES
(AMPHIBIA: ANURA) IN THE CERRADO OF MATO GROSSO DO SUL. 2011. 75 f. Dissertação (Mestrado em Ciências Biológicas) - Universidade Federal de Santa Maria, Santa Maria, 2011.
Autor
Amarante, Débora Delevati do
Institución
Resumen
We studied species richness, abundance and spatial-temporal distribution of tadpole
communities in eight ponds in an area of Cerrado in the state of Mato Grosso do Sul, Brazil.
We carried out this study during a rainy season (October 2009 to March 2010). We
determined the spatial and temporal niche breadth by standardized Levins index, and we used
null models to explore the patterns of niche overlap. Additionally, we evaluated the influence
of environmental descriptors and spatial distribution of ponds on the studied communities
using redundancy analysis (RDA) applied to three phases of the rainy season (outset, middle
and the end). We recorded tadpoles of 18 species belonging to four families: Hylidae,
Leiuperidae, Leptodactylidae, and Microhylidae. Most species was considered specialist
regarding to spatial niche breadth a (BA <0.20), and generalist regarding the temporal niche
breadth (BA> 0.50). The spatial niche overlap did not differ from expected by chance, while
the temporal niche overlap was clearly not random. Niche overlap was negatively correlated
with ecomorphological guilds, even after removed the phylogenetic effects. This pattern
seems figure a mechanism to reduce the competitive pressure among ecologically similar
species. In relation to environmental and spatial components, these presented differential
influence and importance along the rainy season. In early season pond area and the percentage
of marginal vegetation up to 30 cm height were the descriptors related to community
organization. During the full rainy season, the percentage of marginal vegetation up to 40 cm
height, percentage of flat margin profile, pond depth, as well as two spatial co-variables
explained the spatial distribution of species, followed by pure environmental variables and by
pure spatial variables. At the end of rainy season no environmental or spatial and descriptor
was included in the model. The importance of environmental descriptors of spatial
components of spatially structured descriptors varied throughout the rainy season, indicating
that dynamic processes occurs along the time are responsible for the organization of the
studied communities.