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Universidade Federal De Santa Catarina Centro De Ciências Biológicas Departamento De Botânica Programa De Pós-graduação Em Biologia Vegetal
| Content Provider | Semantic Scholar |
|---|---|
| Author | Silva, Fernanda Ribeiro Da |
| Copyright Year | 2008 |
| Abstract | The palms are considered keystone species in tropical forests, because their fruits are very important as feed resource for frugivorous communities during times of scarcity. Palms have been used as evaluation models to understand processes of seed dispersal and seed predation. The main goal of this investigation is to evaluate consequences of fragmentation in these ecological processes. This thesis addresses some ecological processes of Syagrus romanzoffiana (the palm jerivá) in islands environments of Santa Catarina-Brazil. The Parque Municipal da Lagoa do Peri (PMLP) in Santa Catarina Island and Campeche Island, two tropical rainforest sites of different sizes, were studied. PMLP is the most conserved site in Santa Catarina Island with 2000ha of area, this site exhibits a wide variation of potential S. romanzoffiana dispersers. IC has 53ha of area with a huge population of coatis (Nasua nasua) which were introduced in 40 decade. It was investigated the following issues: phenology patterns of S. romanzoffiana in both sites, besides we studied how different animals composition affects seed dispersal and predation. We have also analyzed seed production and pre-dispersal seed predation. As secondary observations, this work related the utilization of empty seeds by ants for nidification. In our observations were found 25 seeds occupied by ant nests, among these nests 11 species were registered. Although there were a huge number of seeds in this site, a low level of ant occupation was presented. This fact was probably due to the small seed size which enables just small species occupation. S. romanzoffiana fruits were observed at all times of the year in both areas, where mature fruit offering was available for 8 months at least. This demonstrates that during the year, fruits are available either in infructecences or on the soil. Seed dispersal and predation presented high levels in both areas, so we concluded that differences in animal richness between the sites did not affect these processes. There were registered a wide variety of frugivorous that consume S. romanzoffiana fruits in PMLP, and at least five could be considered potential dispersers. Although IC had presented a lower diversity of frugivorous, seed dispersal is high probably due to the huge number of coatis. IC had presented more adult trees, population structure could be considered the major difference between the sites. This difference is due to better edge condition in IC. The development of S. romanzoffiana until adult phase is favored by better light conditions. It is noticed that the major pressure of selective on this palm is seed predation in pre-dispersal phase. In this phase more than half of the seeds are consumed by host-specific Curculionidae larves, Revena rubiginosa. In PMLP, seed production is higher and it suffers from the variation in individual and population levels between reproductive years. In the sites occur a high density of seedlings and viable seeds. Years of high seed production might satiate hostspecific predators. In this way, some seeds can escape from predators and they can be dispersed in sites that are favorable for germination and establishment. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://repositorio.ufsc.br/bitstream/handle/123456789/106611/258009.pdf?isAllowed=y&sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
