ABSTRACT
ABSTRACT We aimed to investigate the taxonomic and functional variations of tree component of Araucaria Forest (AF) areas located along an altitudinal gradient (700, 900 and 1,600 m asl), in the southern region of Brazil. The functional traits determined were leaf area, specific leaf area, wood density, maximum potential height and dispersal syndromes and deciduousness. The data were analyzed through a functional and taxonomic dissimilarity dendrograms, community-weighted mean trait values, parametric and nonparametric tests, and Principal Component Analysis. The largest floristic-structural similarity was observed between the lower altitude areas (700 and 900 m asl), whose Bray-Curtis distance was 0.63. The area at 700 m asl was characterized by a predominance of deciduous and semi-deciduous species, with a high number of self- and wind-dispersed species, whereas the area at 1,600 m asl exhibited a predominance of animal-dispersed and evergreen species. It was also observed that there were significant variations for leaf traits, basic wood density and maximum potential height. Over all altitudinal gradient, the ordinations indicated that there was no evidence of functional differentiation among dispersal and deciduousness groups. In conclusion, the evaluated Araucaria Forest areas presented high floristic-functional variation of the tree component along the altitudinal gradient.
Subject(s)
Trees/classification , Biodiversity , Altitude , Species Specificity , Trees/anatomy & histology , Brazil , Forests , BiomassABSTRACT
ABSTRACT: The aim of this study was to characterize the demographic structure and spatial pattern of Campomanesia xanthocarpa (Mart.) O. Berg, Myrcianthes gigantea (D. Legrand) D. Legrand and Myrciaria delicatula (DC.) O. Berg. Within one hectare of Ombrophilous Mixed Forest, all the three populations' individuals were counted and measured with regard to their height and diameter. From the collected data, the assessment of the demographic structure was realized after the individual's size classification. Spatial pattern was determined by applying the Standardized Morisita's Index. C. xanthocarpa and M. delicatula showed an inverted-J frequency distribution in the individuals size classes, which differed from M. gigantea that did not follow the same pattern. The spatial pattern of C. xanthocarpa and M. delicatula populations was found mainly to be aggregated; whereas, M. gigantea showed spatial randomness. The three Myrtaceae populations responded differently with regard to structure and spatial distribution in sites with the same environmental filters.
RESUMO: Objetivou-se caracterizar a estrutura demográfica e o padrão espacial de Campomanesia xanthocarpa (Mart.) O. Berg, Myrcianthes gigantea (D. Legrand) D. Legrande Myrciaria delicatula (DC.) O. Berg, bem como, verificara influência de variáveis ambientais sobre essas populações. Em um hectare de Floresta Atlântica, todos os indivíduos das três populações foram contados e mensurados quanto à altura e diâmetro. A estrutura demográfica foi avaliada após classificação de tamanho dos indivíduos, o padrão espacial pelo Índice de Morisita Padronizado. Campomanesia xanthocarpa e M. delicatula apresentaram distribuição de frequência dos indivíduos em classes de tamanho em J invertido, já a espécie M. gigantea não seguiu o mesmo comportamento. O padrão espacial das populações de C. xanthocarpa e M. delicatula foi, predominantemente, agregado e, para M. gigantea, o padrão foi aleatório. Verifica-se que as populações de Myrtaceae possuem respostas diferenciadas quanto à estrutura e distribuição espacial em sítios com os mesmos filtros ambientais.