Ecologia de hemiepífitas estranguladoras no Parque Estadual da Ilha do Cardoso
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Data
2005-11-21
Autores
Coelho, Luís Francisco Mello [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Hemiepífitas estranguladoras são plantas que crescem sobre árvores (hospedeiros) e posteriormente enviam raízes para conexão com o solo. Depois de alcançar o estoque de água e nutrientes do solo se desenvolvem até atingir um grande porte e se tornarem capazes de se auto sustentar. Durante seu desenvolvimento competem com os hospedeiros por oportunidades de expansão da copa e por água e nutrientes do solo, além de afetarem negativamente a translocação de água e nutrientes pelo sistema vascular de seu hospedeiro devido à constrição provocada no fuste e galhos do hospedeiro pelo sistema de raízes estrangulantes típico dessas plantas. Apesar de serem componentes importantes de florestas tropicais, estudos sobre a estrutura populacional de hemiepífitas estranguladoras são raros, aspecto este que norteou os objetivos do presente trabalho, que tem como proposta levantar a riqueza e densidade das hemiepífitas estranguladoras, analisar e comparar a estrutura populacional e as formas de utilização do dossel florestal entre os gêneros estudados. O estudo foi conduzido nas áreas de Floresta Tropical Pluvial da Serra do Mar e de Floresta Tropical Pluvial de Planície Litorânea, ambas situadas no Parque Estadual da Ilha do Cardoso (PEIC), no extremo sul do litoral paulista. Os dois gêneros amostrados causam dano letal ao hospedeiro e não diferem quanto ao tipo ou freqüência do impacto sobre os hospedeiros, apesar dos diferentes padrões morfológicos do sistema de raízes estrangulantes de cada gênero. As hemiepífitas estranguladoras ocorrem em alta densidade na Ilha do Cardoso e, pelos aspectos de sua ecologia aqui investigados, exercem importante papel na estrutura e regeneração do dossel florestal.
Strangling hemiepiphytes are plants that grow in trees (hosts) and later send their roots to connect with the soil. After reaching the water supply and nutrients in the soil, they evolve to a considerable size and are capable of self-support. Throughout their development they compete with their hosts for opportunities to expand their crowns and to get water and soil nutrients, besides negatively affecting water and nutrients translocation through the vascular system of their host by constricting the host trunk and branch using the root-constrictor system typical of such plants. Therefore, they can cause premature death of their hosts. Despite being important elements in tropical forests, studies of the population structure of strangling hemiepiphytes are rare. This study aims at investigating the richness and density of these strangling hemiepiphytes to further compare population structure of two genera and the ways each uses the forest canopy. The study was conducted in the Plain Tropical Forest and in the Slope Tropical Forest areas within the Cardoso Island State Park (PEIC), situated in the extreme south of the coast of the state of São Paulo, southeast Brazil. Both sampled genera cause lethal damage to the host and do not differ in terms of type or frequency of impact over the hosts, despite the different morphological patterns in the strangling roots systems of each genus. The strangling hemiepiphytes occur in a high density on Cardoso island, and, because of their distinctive biological aspects discussed above, play an important role in the structuring and regeneration of forest canopy.
Strangling hemiepiphytes are plants that grow in trees (hosts) and later send their roots to connect with the soil. After reaching the water supply and nutrients in the soil, they evolve to a considerable size and are capable of self-support. Throughout their development they compete with their hosts for opportunities to expand their crowns and to get water and soil nutrients, besides negatively affecting water and nutrients translocation through the vascular system of their host by constricting the host trunk and branch using the root-constrictor system typical of such plants. Therefore, they can cause premature death of their hosts. Despite being important elements in tropical forests, studies of the population structure of strangling hemiepiphytes are rare. This study aims at investigating the richness and density of these strangling hemiepiphytes to further compare population structure of two genera and the ways each uses the forest canopy. The study was conducted in the Plain Tropical Forest and in the Slope Tropical Forest areas within the Cardoso Island State Park (PEIC), situated in the extreme south of the coast of the state of São Paulo, southeast Brazil. Both sampled genera cause lethal damage to the host and do not differ in terms of type or frequency of impact over the hosts, despite the different morphological patterns in the strangling roots systems of each genus. The strangling hemiepiphytes occur in a high density on Cardoso island, and, because of their distinctive biological aspects discussed above, play an important role in the structuring and regeneration of forest canopy.
Descrição
Palavras-chave
Ecologia vegetal, Hemiepífitas, Mata-pau, Mata atlântica, Ecologia de dossel, Coussapoa, Canopy ecology, Atlantic rainforest, Strangler hemiepiphytes
Como citar
COELHO, Luís Francisco Mello. Ecologia de hemiepífitas estranguladoras no Parque Estadual da Ilha do Cardoso. 2005. xi, 82 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências, 2005.