Francieli de Fátima Missio

NATURAL REGENERATION OF TREE SPECIES IN A CLOUD FOREST IN SANTA CATARINA, BRAZIL

Os objetivos do presente estudo foram caracterizar a regeneracao natural arborea e relacionar esse estrato com o componente adulto e com variaveis ambientais em um fragmento de floresta nebular em Santa Catarina. Em cada uma das 25 parcelas de 20 × 20 m, onde previamente foi realizado um estudo com caracterizacao do componente adulto e de variaveis ambientais, foram estabelecidas subparcelas, com tamanhos diferenciados de acordo com o tamanho das plantas, para a avaliacao dos regenerantes: Classe 1, plantas com altura de 0,15 cm ate 1 m, avaliadas em 5 m2; Classe 2, plantas com altura entre 1 e 3 m, avaliadas em 10 m2, e; Classe 3, plantas com altura maior que 3 m e DAP menor que 5 cm, avaliadas em 20 m2. Foram determinadas: diversidade (indice de Shannon), equabilidade (Pielou), Indice de Regeneracao Natural (IRN), similaridade com o componente arboreo adulto (Jaccard e Bray-curtis), organizacao floristica-estrutural (escalonamento multidimensional nao-metrico - NMDS) e relacao com as variaveis ambientais. Foram amostrados 518 individuos distribuidos em 28 especies. O valor do indice Shannon (2,51 nat/ind) e da equabilidade de Pielou (0,75) sugerem baixa diversidade e elevada dominância ecologica. A especie de maior IRN foi Symphyopappus itatiayensis (Hieron.) R.M.King & H.Rob (19,36%). As similaridades com os adultos foram de 0,45 (Jaccard) e 0,24 (Bray-Curtis), demonstrando baixa similaridade (<0,50). A compactacao do solo foi a unica variavel que apresentou relacao com a regeneracao, o que pode estar relacionado com a presenca de gado no fragmento.

COMPOSIÇÃO FLORÍSTICO-ESTRUTURAL AO LONGO DE UM GRADIENTE DE BORDA EM FRAGMENTO DE FLORESTA OMBRÓFILA MISTA ALTO-MONTANA EM SANTA CATARINA

The objectives of this study were to characterize the floristic and structure of the tree component in Upper Montane Araucaria Forest fragment and to evaluate the influence of the edge effects on tree species organization, structure, richness and diversity. For this, a total of 50, 10 x 20 m, permanent plots divided in five transects spaced, at least, 100 m from each other, were established in the a forest fragment, located in the municipality of Bom Jardim da Serra, SC. The trees with circumference at breast height (CBH) ≥ 15,7 cm were measured (CBH and total height), identified and classified according to the regeneration guilds. The data were analyzed through the index of importance values (IVI), a NMDS analysis (Nonmetric Multidimensional Scaling), a generalized additive model and simple linear regressions. A total of 1,457 individuals, distributed in 29 families, 43 genera and 55 species were surveyed. The most relative important species was Dicksonia sellowiana Hook. There was no influence of edge effect on tree community organization, structure (average diameter, average height and density) and guilds participation. However, values of diversity, richness and evenness were higher at edge areas. We conclude that part of the variation in values related to tree species diversity in the Upper Montane Araucaria Forest was determined by edge distance.

Avaliação da Restauração Florestal de uma APP Degradada em Santa Catarina

This study evaluated the process of restoration in a degraded Permanent Preservation Area (PPA) in the municipality of Pouso Redondo, Santa Catarina state, six years after the initial plantation of trees and isolation of the area. Tree species were surveyed and increment of richness by natural establishment was quantified. Syndromes of propagule dispersion and regeneration guilds were determined. A total of 918 individuals from 73 species were found; 48 (65.8%) of them were species naturally established in the area. 71.2% of the species were classified as zoochoric (71.2%), and 54.8% as light demanding for climax. After six years, the restoration process was characterized by a trend of richness increment and replacement of initial by late successional species, indicating the relevance of the natural regeneration mechanism.

Heterogeneity of a Tree Species Community in an Alluvial Area of Santa Catarina, Brazil

The aim of the present study was to characterize the floristic-structural heterogeneity of the tree species in an alluvial forest remnant considering three sectors: forest-river edge, forest interior and forest/non-forest matrix edge. Forty-eight plots of 200 m2 were allocated and all tree individuals with a diameter at breast height (dbh) equal to or greater than 5 cm were measured and identified. Data was analyzed by Shannon’s diversity index, Pielou evenness and phytosociological descriptors. Plots were ordered through NMDS. Sixty-six species were sampled and Myrtaceae was found to be the richest family. Diversity and evenness reached 2.96 and 0.71, respectively. Sebastiania commersoniana (Baill.) L.B.Sm. & Downs presented the highest importance value (21.22%). The NMDS showed that tree components are spatially partitioned according to sectors, therefore indicating floristic-structural heterogeneity.

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.

Similaridade florística das florestas superomontanas no domínio Atlântico, Brasil

This study investigated the floristic similarity of the tree component of 39 upper montane forest fragments in Atlantic domain, Brazil, and the influence of geographic and climatic variables on the patterns observed. It was created a binary matrix of presence and absence of the tree species compiled from the 39 floristic and phytosociological survey. For the relationship of the floristic composition of the areas with the environmental and spatial variables, the geographic coordinates and climate data of each area were extracted. The floristic similarity of the fragments was measured using a dendrogram and for determination of environmental and spatial variables influence on floristic patterns, a nonmetric multidimensional scaling analysis (NMDS) was used. The dendrogram analysis and the NMDS showed the formation of clusters, predominantly among fragments located in the same phytogeographic unit. The existence of an environmental gradient based on the climatic conditions was observed. In areas with higher thermal seasonality, annual temperature range, precipitation, latitude and longitude, upper montane forests with rain forest matrix occurred, and in areas with higher average temperature, daily temperature range, isothermality, seasonality of precipitation and minimum temperature in the coldest month, upper montane forests with seasonal matrix occurred.