Plantas ornitófilas, com enfoque em Sinningia sceptrum (Mart.) Wiehler (Gesneriaceae), em fragmento de Floresta Atlântica: aspectos reprodutivos e rede de interações mutualísticas

• Autor(a) principal: Leone, Fernanda Regis
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2558
• topic: Beija-flores; Floração; Hercogamia; Aninhamento; Generalização; Modularidade; Redes complexas; Hummingbirds; Flowering; Herkogamy; Nesting; Generalization; Modularity; Complex networks; CNPQ::CIENCIAS BIOLOGICAS::BOTANICA

Hummingbirds are among the most common pollinators in Neotropical vegetation communities. Many studies have been performed about the composition of the ornithophilous flora and its interactions with hummingbirds in areas of the Atlantic Forest, but little is known in areas classified as Semi Deciduous Forest. With the need to fill this gap in knowledge, was performed in a fragment of the Semi Deciduous Forest, a case study to recognize aspects of the reproductive biology of Sinningia sceptrum and a study about a community of ornithophilous plants and their mutualistic interactions with hummingbirds. The fragment, known as the Mata do Paraíso, has 194,3 ha. and is located in 20°45 S and 42°54 W, in the Viçosa, Zona da Mata, Minas Gerais. The flowering of S. scpetrum was annual-intermediary and seasonal. The intensity of reproductive phenophases varied according to water availability during the rainy season. Flowers are diurnal, protandry and herkogamy, thus dependent on pollinators. Although xenogamy and geitonogamy equality contribute to produce fruits and seeds, the effect of endogamic depression was observed on germination of seeds from geitonogamy. The main pollinator of S. sceptrum was the hummingbird Phaethornis pretrei; P. squalidus was an occasional pollinator and P. ruber was a nectar thief. The results of the reproductive system reinforce the need the dependence of S. sceptrum by hummingbirds to ensure the reproductive success of S. sceptrum. In the study of mutualistic interactions network between hummingbirds and ornithophilous plant community were identified 24 plant species visited by 12 species of hummingbirds and was shown the importance of these interactions for maintenance of both groups in the community.The families Rubiaceae and Acanthaceae were predominant along with hummingbirds of the genera Phaethornis and Amazilia, all with three species each. The interactions were highly nested, generalized and weakly modular, a result similar to that found in sub- networks, i.e., restricted to one or a few groups of pollinators and plants. The hummingbirds Phaethornis pretrei, P. ruber, P. squalidus and Thalurania glaucopis presented interactions with many species. Those interactions were indicating that these pollinators are essential for maintaining the connection between the network.