Karine Souza

Biological invasion by Hovenia dulcis Thunb. in forest fragments in Upper-Uruguay Region, Brazil.

Buscou-se caracterizar a composicao floristico-estrutural do componente arboreo de uma area contaminada por Hovenia dulcis Thunb., determinar a relacao da distribuicao da especie invasora com o estagio sucessional e verificar a relacao da presenca da especie invasora com padroes de diversidade e de estruturacao da comunidade. O estudo foi realizado em uma area ciliar do reservatorio da Usina Hidreletrica de Machadinho, em Santa Catarina. O levantamento foi conduzido em 48 parcelas de 200 m2 cada, dispostas em oito blocos. Dentro das parcelas, todos os individuos arboreos com Circunferencia Medida a Altura do Peito (CAP) igual ou superior a 15,7 cm foram medidos (CAP) e identificados. Os dados foram analisados por meio dos descritores fitossociologicos, Indice de Invasao Biologica (IIB), indices de diversidade, escalonamento multidimensional nao metrico, analise de variância multivariada permutacional, analise de especies indicadoras e o indice de c-score. Foram amostradas 66 especies, com a de maior Valor de Importância (VI) Ocotea puberula (Rich.) Nees (10,79%). H. dulcis ocupou a setima posicao em VI (4,04%), e o IIB foi de 0,47. Os blocos foram classificados em grupos sucessionais medios e avancados, com diferencas floristico-estruturais entre eles (p = 0,001). H. dulcis associou-se com areas em estagio sucessional mais inicial, com menor diversidade de especies arboreas e ausencia de estruturacao da comunidade, referente a segregacao das especies nas parcelas. Conclui-se que a invasao por H. dulcis nao ocorreu de forma espacialmente homogenea, sendo determinada pelas caracteristicas ecologicas da comunidade residente.

SHORT-TERM IMPACT OF A HYDROELECTRIC POWER PLANT’S RESERVOIR ON THE TREE COMPONENT IN AN ECOTONAL AREA IN SANTA CATARINA

1 Received on 03.03.2015 accepted for publication on 28.06.2017. 2 Universidade do Estado de Santa Catarina, Programa de Pós-Graduação em Engenharia Florestal, Lages,SantaCatarina,Brasil.Email:<carla_engflorestal@yahoo.com.br>,<amandaeng.f@gmail.com>,<juli_ajuri@hotmail.com>,<mariele.ferrer@hotmail.com>, <pamniederauer@gmail.com>,<vanessasoboleski@hotmail.com>,<rhodineli@hotmail.com>,<a.line_cruz@yahoo.com.br>, <karisouza@hotmail.com> , <chayanesouza8@gmail.com> and <jessica.oneda@hotmail.com.br>. 3 Universidade do Estado de Santa Catarina, Departamento em engenharia Florestal, Lages, Santa Catarina, Brasil. E-mail: <carol_sil4@yahoo.com.br> and <higuchip@gmail.com>. 4 Universidade do Estado de Santa Catarina, Programa de Pós-Graduação em Produção Vegetal, Santa Catarina, Brasil. Email: <karynaflorestal@yahoo.com.br>. *Corresponding author.

POTENCIAL REGENERATIVO DE UMA FLORESTA ECOTONAL NA REGIÃO DO ALTO URUGUAI EM SANTA CATARINA

We aimed to evaluate the regenerative potential of the tree component in an ecotonal area between Araucaria and Deciduous forests, in the Upper Uruguay region, Santa Catarina state. For this, a floristic-structural description of the regenerative component was conducted for different size classes and the floristic similarity among classes and adult component was verified. Three classes were considered for the regenerative component: Class 1, plants from 0.2 up to 1 m high, Class 2, plants greater than 1 m up to 3 m high, and Class 3, plants greater than 3 m high, with cbh < 5.0 cm. Information about the adult component for the same sampling units were extract from the database of the Dendrology and Phytosociology Laboratory (LABDENRO), of Santa Catarina State University. All the regenerative species were classified into regeneration guilds (pioneers, light demanding climax, shade tolerant climax), based on literature review and on field observations. For the whole component and for each size class, the Shannon diversity (H’) and Pielou Eveness (J) indexes, and the Class (RNC) and Total (RNT) Natural Regeneration Indexes were determined. The floristic similarities between components were obtained by Sorensen Index. A chi-square applied to a contingency table was conducted to verify the existence of association between the distribution of individuals belonging to different regeneration guilds and size classes. A total of 771 regenerative individuals were sampled, belonging to 52 species, whose H’ and J were, respectively, 3.06 and 0.77. The species with the greatest RNT was Nectandra megapotamica (Spreng.) Mez. The similarity with the adult component varied between 0.46 for Class 3 and 0.62 for Class 1. In all size classes, there was the predominance of individuals of climax light demanding species. We conclude that the adult species component was mostly represented within the smaller plant size class, where the largest proportion of sampled individuals was found.

PARTIÇÃO DA VARIAÇÃO FLORÍSTICO-ESTRUTURAL DO COMPONENTE ARBÓREO EM UMA FLORESTA OMBRÓFILA MISTA ALUVIAL NO SUL DO BRASIL

This study aimed to evaluate the influence of spatial structure and environmental variables on floristic-structural organization of the tree component, in an Alluvial Araucaria Forest, in southern Brazil. To do so, 48 200 m 2 sampling units were allocated in the study area, located in the municipality of Lages, SC state. All trees within the sampling units, with diameter at breast height (dbh) equal to or greater than 5 cm were identified. The environmental and spatial variables were measured in each sampling unit. The data were analyzed through Mantel Correlogram, Variation Partitioning, Redundancy Analysis, analysis of Principal Coordinates of Neighbor Matrices and correlation tests. A total of 1,462 individuals, belong to 66 species, were sampled. Together, the environmental and spatial variables explained 24.13% of total variation, with the largest part (15.22%) being spatially structured. The significant environmental variables were topography (maximum elevation difference) and fertility (bases sum and P). It is possible to conclude that the tree component is organized as a floristic-structural gradient. Furthermore, the results suggest that the inundation regime and the presence of flood prone areas were relevant for micro-habitat definitions, that influenced the distribution of species

INTER-RELAÇÃO ENTRE PAISAGEM, ORGANIZAÇÃO FLORÍSTICO-ESTRUTURAL E DEMOGRAFIA DO COMPONENTE ARBÓREO EM FLORESTA COM ARAUCÁRIA

The aim of this study was to investigate the interactions among the landscape spatial configuration, the floristic-structural organization and demographic rates of the tree component of araucaria forest fragments system, in Lages, Santa Catarina state. To do so, we developed a conceptual model of inter-relationship that was evaluated by Structural Equation Modeling. In 2010, the landscape metrics (area, distance from the nearest neighbor and edge-core ratio) and first vegetation inventory data were obtained. In this case, permanent plots were allocated in five forest fragments and forest corridor, where all tree individuals with cbh (circumference at breast height, measured at 1.30 ground) greater than or equal to 15.7 cm were identified and measured. In 2014, the second inventory was conducted, with the inclusion of recruits and counting dead and survivor’s individuals, followed by the determination of demographic rates. The data were analyzed through Principal Component Analysis (PCA), Principal Coordinates Analysis (PCoA), Structural Equation Modelling, and Generalized Linear Models (GLM). The results showed that the landscape structure (PCA 1) had a significant influence only on the floristic-structural organization of the tree component, indicated by the preferential distribution of tree species in response to fragmentation intensity. In turn, the demographic rates (basal area gain and loss rates, and mortality rate) were influenced by structural aspects of vegetation (abundance and basal area). We conclude that there was floristic-structural variation associated to the spatial configuration of fragments in the landscape and that the demographics rates presented relation with forest successional stage, synthetized by structural variables of basal area and abundance.

Partição de nicho por grupos funcionais de espécies arbóreas em uma floresta subtropical

This study aimed to investigate functional attributes of tree species along different topographic position, in a forest located in Upper Uruguay region, in Santa Catarina. The wood density (WD), potential height (Hmax), leaf area (LA), specific leaf area (SLA), leaves renovation regime, regeneration and dispersal guilds were determined for the 20 most abundant species in the sampled area. The functional structure was evaluated through a community weight matrix (CWM) of traits values for each sampling unit. Mean values of elevation, declivity and curvature were extracted for each sampling unit, from a Terrain Digital Model in a resolution of 1 m. The data was analyzed through linear correlations, Principal Coordinates Analysis (PCoA), Principal Components Analysis (PCA) and linear simple model. The results indicated significant and negative correlation between Hmax x LA and Hmax x SLA. The topographic gradient significantly influenced the functional structure of tree component. It is concluded that the occupation of different positions along the topographic gradient and the forest vertical profile by tree species were mediated by different ecological strategies.

Floristic-functional variation of tree component along an altitudinal gradient in araucaria forest areas, in Southern Brazil

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.

Relação Hipsométrica para Pinus taeda L. em Diferentes Fases do Ciclo de Corte

This study aimed to evaluate the different phases of the cutting cycle, seeking a proper hypsometric rate to estimate the height of these different phases in a reforestation of Pinus taeda. The study consisted of five treatments, being the fifth the combination of the data belonging to the other treatments. The sampling followed the fixed area method where plots size and number of dominant trees varied with each cutting cycle. The plots location was defined by simple random sampling (eight portions by cutting cycle). We determined the statistical adjustments, adjusted coefficient of determination, standard error and residual analysis. We performed the Graybill identity test to assess the need to use different models for different age classes. Results showed that there are significant differences between adopting a specific model to each stage and use a single best model for the full settlement.