morphological variation of the leaves of Aechmea distichantha Lem. plants from contrasting habitats of a Chaco forest: a trade-off between leaf area and mechanical support

摘要: Morphological variation of the leaves Aechmea distichantha Lem. plants from contrasting habitats a Chaco forest: trade-off between leaf area and mechanical support). Several authors have reported phenotypic plasticity for bromeliad growing in habitats. physiological differences seem to be an adaptation water light use, but there is also compromise carbon gain costs sustaining static dynamic loads. We hypothesized that plastic responses habitat at level represent photo- synthetic capturing support. In this study, we measured morphological architectural vari- ables central basal understory forest edge, as well anatomical variables each habitat. Understory had longer leaves, larger blade areas greater length/width ratios than forest-edge plants. Blades were less erect, succulent, thicker fiber tissue surrounding vascular bundles higher curvature index blades Thus, increased their flex- ural stiffness by modifying structure shape leaves. On other hand, stomatal density trichome on adaxial sides These patterns could adaptations gas exchange reduce vulnerability photoinhibition sun when compared shade Finally, most significantly different positions. results support our view photosynthetic (for capture use) ReSUmO: (Variacoes morfologicas de folhas plantas contrastantes uma floresta do Chaco: compensacao entre foliar e suporte mecânico). Diferencas fisiologicas em nivel parecem ser adaptacao ao uso da agua luz, mas tambem existe o ganho carbono os custos sustentar cargas estaticas dinâmicas. Nossa hipotese que respostas plasticas no representam fotossintetica para captacao luz apoio mecânico. Neste estudo, medimos variaveis arquitetonicas nas centrais basais distichantha, sub-bosque das bordas floresta, assim como anatomicas cada Lâminas foliares foram menos eretas, suculentas, com contendo fibras pearedes espessadas torno dos feixes vasculares indice curvatura maior floresta. Assim, aumentaram sua rigidez flexao, modificando estrutura tecidos, bem forma suas folhas. Por outro lado, lâminas borda apresentaram densidade estomatica tricomas face sub-bosque. Esses padroes podem adaptacoes um intercâmbio reducao vulnerabilidade fotoinibicao sol sombra. Finalmente, parte significativamente diferentes posicoes. Estes resultados suportam nossa opiniao ha compensacao, folha, (para agua) Palavras-chave: anatomia foliar, biomecânica, bromelias, morfologia plasticidade fenotipica.