ResumoRespostas plásticas em plantas podem ser induzidas pela heterogeneidade espacial, sendo a restinga um ecossistema favorável à compreensão dessas respostas em função das condições ambientais limitantes que apresenta. O presente estudo avaliou de forma comparada as respostas plásticas foliares em duas populações de Tibouchina clavata (Melastomataceae) habitando as formações herbácea e florestal da restinga do Parque Estadual Acaraí, localizada em São Francisco do Sul-SC. Nos dez indivíduos amostrais de cada formação foram mensurados atributos morfoanatômicos foliares e do caule. Variáveis ambientais como nutrição edáfica, umidade gravimétrica e radiação luminosa foram mensuradas. As médias obtidas para cada variável foram comparadas pelo teste t de Student. Para cada atributo, foi calculado o índice de plasticidade fenotípica. Atributos morfológicos e anatômicos diferenciaram as duas populações entre si, sendo a população da formação herbácea tipicamente xeromórfica em função das condições ambientais mais restritivas. Condições mais favoráveis dadas pela maior oferta de nutrientes e água no ambiente florestal proporcionaram maior investimento dos indivíduos em crescimento. Atributos anatômicos mostraram-se pouco plásticos quando comparados aos morfológicos. T. clavata demonstrou ser uma espécie morfologicamente plástica que permite a compreensão dos efeitos dos fatores limitantes da restinga sobre o desenvolvimento vegetal, com destaque às condições nutricional, hídrica e lumínica que induzem ao xeromorfismo. Palavras-chave: índice de plasticidade, floresta de restinga, morfoanatomia funcional, planície costeira, restinga herbácea. AbstractPlastic responses in plants can be induced by spatial heterogeneity, being the restinga a supportive ecosystem to understand these responses due to its limiting environmental conditions. This study evaluated so compared the leaf plastic responses in two populations of Tibouchina clavata (Melastomataceae) inhabiting the herbaceous and forest formations of the restinga Acaraí State Park, located in São Francisco do Sul-SC. In the ten individuals sample of each formation were measured leaf morphoanatomic attributes and stem. Environmental variables such as edaphic nutrition, gravimetric moisture and light radiation were measured. Mean values for each variable were compared by the Student t test. For each attribute, it was calculated phenotypic plasticity index. Morphological and anatomical attributes differentiate the two populations together, and the population of herbaceous formation typically xeromorphic due to more stringent environmental conditions. More favorable terms given by the increased supply of nutrients and water in the forest environment provided greater investment of growing individuals. Anatomical attributes were shown little plastic when compared to the morphological. T. clavata it proved to be a morphologically plastic kind that allows the understanding of the effects of the limiting factors of the restinga on plant development, with emphasis on nutrition, ...

Wood anatomical traits respond to environmental variables and among them, soil has a direct impact on secondary xylem. This study compares the wood anatomy of two populations of Ficus cestrifolia occurring in two lowland formations of Southern Brazil (MAQ and SJS) with similar climate but different soil conditions. Wood samples were collected at breast height and prepared according to standard wood anatomy techniques. Soil samples were collected and subjected to a nutrient analysis. Wood was described quali and quantitatively. The qualitative wood anatomical features of both populations were similar. Some quantitative differences were observed. In MAQ area, the levels of macro- and micronutrients were higher than in SJS. Its population presented higher vessel frequency, thicker-walled fibers, and lower vulnerability index. SJS's population had longer fibers, wider rays and a higher ray frequency, and higher vulnerability index. This suite of characters indicates that the MAQ population has a safer and more efficient xylem structure for water conduction. Under the influence of similar climate and soil type, differences regarding wood anatomical traits found between the two populations of Ficus cestrifolia can thus be regarded as an ecological response to the micro-environmental soils nutrients composition.

Mangroves represent an environment of great heterogeneity and low diversity of plant species that have structural and physiological adaptations linked to a high salinity environment. Laguncularia racemosa is a typical tree species in mangroves and transitional zones. This study aimed to compare the wood anatomy of L. racemosa (Combretaceae) in two different forests (mangroves and transitional forests), which have different soil conditions. For this, we obtained wood and soil samples in March 2016. We analyzed soil nutritional contents in one 15 cm deep soil sample per forest type. In addition, we selected five mangrove trees in each formation for wood anatomy analysis and took one wood sample per individual, per area. We prepared histological slides and separated materials following standard methods for wood anatomy studies. Soil analysis showed that mangrove soils had higher phosphorus, potassium and calcium contents. The transitional soil had lower pore water salinity and soil pH, probably due to high aluminum levels. Anatomical attributes differed between different forest populations. In the different wood aspects evaluated, we obtained higher values in mangrove individuals when compared to the transitional forest population: vessel elements length (375.79 mm), tangential vessels diameter (75.85 mm), frequency of vessels (11.90 mm) and fiber length (889.89 mm). Moreover, parenchyma rays height was larger in the samples of the transitional forest (392.80 mm), while the mangrove population presented wider rays (29.38 mm). The structure of the secondary xylem in the studied species apparently responds to edaphic parameters and shows variations that allow it to adjust to the environmental conditions. The population of the transitional forest showed a secondary xylem that invests more in protection than the mangrove population. Rev. Biol. Trop. 66(2): 647-657. Epub 2018 June 01.

-(Structural adaptations of seven shade shrubs in species of Tropical Rain Forest). Understory species are adapted to shade condition imposed by the canopy. This study characterized, by means of leaf attributes, the strategies used by different species of understory. The study was conducted at the Botanical Garden of the University of the Region of Joinville, Santa Catarina State, Brazil. Seven shade species were selected. Of each species, five individuals were selected and 25 leaves were collected for morphological and anatomical analysis and chlorophyll content. The incident light intensity on each specimen was measured. The results confirmed the high degree of shading in understory plants. The ratio chlorophyll a/b was >1 and therefore contrary to expected. Statistical tests showed the existence of patterns of response to shading, morphologically characterized by fresh weight, leaf area, length and width of the blade and leaf specific area and, anatomically, the thickness of the spongy parenchyma. The convergence of these attributes is associated with greater use of light that reaches the understory. Keywords: leaf traits, light, rain forest, understory RESUMO -(Adaptações estruturais de sete espécies ciófitas arbustivas de Floresta Ombrófila Densa). As espécies do subosque são adaptadas à condição de sombreamento imposta pelo dossel. O presente estudo caracterizou, por meio de atributos foliares, as estratégias utilizadas por diferentes espécies de subosque. O estudo foi realizado no Jardim Botânico da Universidade da Região de Joinville, SC, Brasil. Foram selecionadas sete espécies ciófitas. De cada espécie foram selecionados cinco indivíduos, dos quais 25 folhas foram coletadas para análise morfoanatômica e de teor de clorofila. A intensidade luminosa incidente sobre cada espécime foi medida. Os resultados confirmaram o alto grau de sombreamento das plantas em subosque. A razão clorofila a/b foi >1 e, portanto, contrária a esperada. Os testes estatísticos evidenciaram a existência de padrões de resposta ao sombreamento, caracterizados morfologicamente pela massa fresca, área foliar, comprimento e largura do limbo e área específica foliar e, anatomicamente, pela espessura do parênquima lacunoso. A convergência destes atributos está relacionada ao maior aproveitamento da luz que atinge o subosques.