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Estudo de populações de Schizolobium parahyba (Vell.) S.F. Blake (Leguminosae: Caesalpinoidae) para avaliação do seu potencial invasor
(Universidade Federal de São Carlos, 2011-02-01) Silva, Talita Ariela Sampaio e; Matos, Dalva Maria da Silva; https://lattes.cnpq.br/4728734263109138; https://lattes.cnpq.br/1292408753626328
Schizolobium parahyba (Vell.) S.F. Blake is a pioneer heliophyte species, with irregular and discontinuous dispersion. It is native and exclusive of Atlantic Rainforest, however, due to its high growth rate and to the shape of its crown, S. parahyba is recommended for forest restoration in areas of Tropical Semideciduous Forest. Currently, it has been questioned the use of this species in forest restoration. Considering that tree species that have 1) phenotypic plasticity and / or tolerance and 2) formation of persistent seed bank, are capable to keep stable populations in different environments, the hypothesis of this research is that S. parahyba can become invasive in Semideciduous Forest fragments. To test this hypothesis, we analyzed the morphology and growth form of the species in the Atlantic Rainforest and Semideciduous Forest, as well as ontogenetic and spatial structures present in both physiognomies. This dissertation is divided into four chapters. Firstly, I contextualize and justify this research. Then, I make a brief description of physiognomies studied, as well as a characterization of sampling sites. In Chapter 3, I compare the allometric relationships and architectural models for the different populations. Finally, in Chapter 4, I compare the ontogenetic and spatial structures for the species between different sampling sites in order to detect whether the species is able to establish stable populations in Semideciduous Forest. After evaluation of morphological characters, populations were divided into four ontogenetic stages: a) seedling, b) juvenile c) subadult, and d) adult. The evaluation of the architectural model of S. parahyba showed no difference in the morphology of the crown of individuals between biomes. The allometry analysis showed that there were differences between the growth patterns of S. parahyba between biomes for seedlings and for the pooled data; however, allometric relationships had no difference between adults. The total individuals abundance in Semideciduous Forest was lower than in the Rainforest. We found no single pattern of ontogenetic structure for the studied populations. There were found individuals of intermediate ontogenetic stages in Semideciduous Forest fragments. In all populations, S. parahyba was distributed in aggregates; however, it was also found scattered individuals within the fragment. The results indicate that S. parahyba shows tolerance and plasticity in response to environmental differences, which are important characteristics when assessing the status of an alien species. Finally, from the results obtained, it can be assumed that S. parahyba may become invasive in fragments of Semideciduous Forest.
Ecologia populacional de Euterpe edulis e os efeitos da introdução de Euterpe oleracea na floresta atlântica no Estado de São Paulo
(Universidade Federal de São Carlos, 2011-02-01) Tibério, Fernanda Cristina dos Santos; Matos, Dalva Maria da Silva; https://lattes.cnpq.br/4728734263109138; https://lattes.cnpq.br/0662110481008557
The main objectives of this dissertation were to evaluate the risks of introduction of Euterpe oleracea in the Atlantic Rainforest and its influence over a native population of Euterpe edulis. We investigated the ecological and morphological features of these species also including pre-existing data about hybrids experimentally produced between them (Chapter 1). We did the populations sampling in two areas of Atlantic Rainforest, in southern São Paulo state: Carlos Botelho State Park (CBSP) and Ilha do Cardoso State park (ICSP). At CBSP, we sampled the co-occurring populations of E. edulis and E. oleracea and at ICSP we sampled the control population for E. edulis, which is free from E. oleracea introduction. We evaluated the characteristics of growth in diameter and height of these populations and its ontogenetic stages through the allometric relationships between diameter and height (Chapter 2). We also analyzed population ecology and distribution of these three species (Chapter 3). For the co-occurring populations we evaluated the fruit biometry and observed the frugivorous bird community (Chapter 3). Our results indicated that two Euterpe species may be well represented for the same ontogenetic stages and the three studied populations presented similar allometry. Concerning to population ecology we observed that E. edulis population at CBSP presents total individuals density lower that ICSP population. Both E. edulis populations do not show a significant aggregation. Population of E. oleracea shows a reduced N, high aggregated distribution and is also capable of dispersing itself outside the original range of plantation. We also observed that these species produce morphologically similar fruits but with different sizes, with bigger fruits from E. oleracea and smaller from hybrids. Finally, we detected that E. oleracea shares the same guild of frugivorous birds and may displace dispersers from E. edulis. We concluded that E. oleracea is capable to successfully establish, reproduce and disperse itself and, thus, it is an invasive species in Atlantic Rainforest. Its introduction affects ecological processes linked to pollination, gene fluxes and frugivore and seed dispersion. These changes may be related to genetic mixtures of populations and decreasing of population of E. edulis. Finally, the introduction of E. oleracea may perform one more threat to maintenance of E. edulis populations, which are already threatened by over exploitation.