AbstractsBiology & Animal Science

Marcgravia longifolia, a keystone resource for vertebrates in Western Amazonia?

by Filipa da Paciência




Institution: Universidade de Lisboa
Department:
Year: 2014
Keywords: Ecologia; Recursos chave; Amazónia - Perú; Teses de mestrado - 2014
Record ID: 1324216
Full text PDF: http://www.rcaap.pt/detail.jsp?id=oai:repositorio.ul.pt:10451/15317


Abstract

Tese de mestrado. Biologia (Biologia da Conservação). Universidade de Lisboa, Faculdade de Ciências, 2014 Defining Keystone Plant Resources (KPRs) has been a difficult task amongst researchers. The most common parameters to describe a KPR relate to the impact of the latter on vertebrate assemblages, their fruit abundance and reliability and their importance during periods of fruit scarcity. This study, aims to fill a gap in the knowledge of Marcgravia longifolia ecology. This liana species is present in the Neotropics, and has the particular characteristic of producing fruits throughout its trunk, from low levels to the top. Therefore, we proposed it as a candidate KPR, since it can feed a wide range of vertebrates at different forest strata. The research was conducted at the Estación Biológica Quebrada Blanco (EBQB), in the Peruvian Amazon. Focal observations on different Marcgravia longifolia individuals revealed visitations by 17% by the bird species assemblage that exists at Quebrada Blanco (with approximately 324 species). When analyzing only species that actually fed on Marcgravia longifolia fruits, this percentage was still significant (14%). Additionally, phenology records showed that this species produced a high amount of fruits (ranging from 1516 to 5706 fruits per individual), while simultaneously having flowers available (with nectaries providing nectar). Fruits were shown to carry a high level of sugar, proteins and lipids, which potential makes them a very important resource for vertebrates in the community. Curiously, fruits also contained a considerable amount of tannins and phenols. These might constitute deterrents for vertebrate consumers of M. longifolia that are not efficient seed dispersers. Recognizing KPRs is of extreme importance when projecting or monitoring conservation areas, as well as for the creation of new policies and guidelines. However, it is important to highlight that the keystone status is not restricted to species, but instead context-dependent, with the community structure being the main responsible for this categorization. A definição de recursos-chave não tem sido uma tarefa fácil entre investigadores. No entanto os parâmetros mais utilizados para a descrição de recursos-chave, estão relacionados maioritariamente com o seu impacto na comunidade de vertebrados, a sua abundância e fiabilidade na época de frutificação e finalmente com a sua importância durante períodos de seca e escassez alimentar. Este estudo visa o preenchimento de uma lacuna sobre a ecologia da Marcgravia longifolia, uma espécie de liana Neotropical que possui a característica peculiar de produzir infrutescências com frutos ao longo de todo o tronco desde os níveis mais baixos até à canópia, assim como inflorescências e néctar. Assim sendo, propõe-se esta liana como uma candidata a recurso-chave, devido à sua particularidade de poder ser utilizada por um grande leque de vertebrados que vivem em diferentes estratos da floresta tropical. O único estudo efectuado com base nesta espécie pertence a Tirado…