No abstract

The objective of this study was to understand the different morpho-physiological strategies of Ligustrum lucidum, an invasive species occurring in Brazilian forest fragments under heterogeneous light conditions. Ten individuals of L. lucidum were selected and evaluated for morphological of the leaves and physiological traits. For morphological parameters were evaluated: length, width, area, angle, petiole length, dried mass, total thickness, palisade parenchyma and spongy parenchyma thickness, abaxial and adaxial epidermis thickness, stomata density, leaf density and specific leaf area. The physiological traits were vapor-pressure deficit, assimilation rate, CO 2 substomata concentration, intrinsic water-use efficiency, transpiration rate and stomatal conductance. All the physiological variables and most morphological variables presented significant differences between light conditions. Phenotypic plasticity indexes were not high as expected. However, phenotypic integration among the morphological and physiological attributes appeared to explain better these results, as observed on the relationship among assimilation rates, palisade parenchyma thickness and SLA. Phenotypic integration could increase the species adaptive responses efficiency, making it more competitive to occupy and to establish in new niches.

In ombrophilous forests, light stratifi cation provokes diff erent adjustments by plants for better use of the environmental conditions of each stratum. Among the morphological traits that vary with strata, the presence of bundle sheath extensions (BSEs) is related to water transport, photosynthesis, and leaf mechanical support and classifi es leaves as homobaric or heterobaric. Th is study analyzed the proportion of these types of leaves in a Lowland Ombrophilous Dense Forest (LLODF) and a Mixed Ombrophilous Forest (MOF), and among the strata of each forest type. Th e morphological leaf traits of 89 LLODF tree species and 57 MOF tree species were examined. Th e proportion of homobaric and heterobaric leaves did not diff er between forests. However, in both forest types, the distribution of species with heterobaric or homobaric leaves depended on strata, with heterobaric species occurring mainly in higher strata, and homobaric species in lower strata. Th us, light stratifi cation acts as an ecological fi lter on the composition of the vegetation of these forests, favoring heterobaric species in places with higher light intensity and temperature, such as the highest strata of canopy. On the other hand, homobaric species are more frequent in lower strata, where light is less available and humidity higher.

RESUMOSerapilheira é a camada formada pela deposição e pelo acúmulo do material proveniente das espécies vegetais e representa a maior contribuição da entrada de nutrientes nos ecossistemas de manguezal. �s variações encontradas na produção desse material são resultantes da ação de diferentes fatores ambientais e intrínsecos das espécies. Este estudo teve como objetivo estimar e comparar a produção da serapilheira de dois bos�ues de mangue no estado do Paraná�� com diferentes padrões estruturais. Foram instalados 1� coletores em cada área�� e realizaram�se as coletas mensalmente. Em ambas as áreas�� a fração folhas foi o principal componente da serapilheira�� seguida por ramos�� material reprodutivo e miscelânea. �s espécies apresentaram maior deposição de folhas e material reprodutivo nos meses com maior temperatura e maior precipitação. � salinidade parece ser o fator �ue mais influencia a produção total de serapilheira�� resultando em uma bai�a produtividade anual �uando comparada com outras áreas de latitudes semelhantes. Palavras-chave: �ntonina�� �uaratuba�� mangue�� material decíduo. ABSTRACTLitter is the layer formed by the deposition and accumulation of material from plant species and represents the largest contribution to the entry of nutrients in mangrove ecosystems. The variations found in the production of this material is a result of the action of different environmental and intrinsic factors from the species. This study aims to estimate and compare the production of litter from two mangroves in the state of Paraná�� with different structural patterns. 1� collectors were installed in each area and samples were collected monthly. In both areas�� the fraction of leaves was the main component of litter�� followed by branches�� reproductive material�� and miscellanea. Species showed greater deposition of leaves and reproductive material in the months with higher temperatures and precipitation. Salinity seems to be the main factor affecting the total production of litter among other soil characteristics.