André Felipe Hess

Relações florísticas e fitossociologia de uma Floresta Ombrófila Mista Montana Secundária em Lages, Santa Catarina

O presente estudo teve como objetivos caracterizar a estrutura fitossociologica de um fragmento de floresta secundaria em Lages, SC, contextualizar a composicao floristica do componente arboreo do fragmento em relacao a outros remanescentes da regiao do Planalto Sul-Catarinense e avaliar a influencia de variaveis geograficas e climaticas sobre os padroes observados. O levantamento da composicao floristica e estrutural da vegetacao arborea, do fragmento estudado, foi conduzido em 25 parcelas de 400 m2, onde todos os individuos arboreos com DAP (diâmetro medido a altura do peito) ≥ 5 cm foram medidos e identificados. Para o estudo das relacoes floristicas entre o fragmento estudado e outros remanescentes da regiao foi utilizada a Arvore de Regressao Multivariada, que utilizou matrizes floristicas de especies arboreas de presenca e ausencia e de variaveis geograficas e climaticas de cada remanescente. Foram encontradas 87 especies, distribuidas em 36 familias botânicas. As especies de maior valor de importância no fragmento estudado foram Araucaria angustifolia (Bertol.) Kuntze e Podocarpus lambertii Klotzsch. A distribuicao diametrica da comunidade demonstrou padrao proximo ao J invertido e as populacoes tiveram padroes de distribuicao diferenciados. Foram descriminados tres agrupamentos floristicos associados a sazonalidade termica e a temperatura media anual. O presente fragmento esteve agrupado a outras areas de sazonalidade termica maior ou igual a 3,053°C.

Exatidão de dendrômetros ópticos para determinação do volume de árvores em pé

The aim of this paper is to verify the accuracy of the optical dendrometers Criterion 400 and RC3H by studying the quality of measures of wood volume determination of standing trees through these dendrometers. The study was developed at the Experimental Station of Forest Sciences, in Itatinga, Sao Paulo state, which belongs to the University of Sao Paulo (ESALQ / USP). It was sampled a total of 175 trees in three plots of Eucalyptus grandis. The stem diameter of standing trees was measured by the two optical dendrometers at distances of 0.1, 0.4, 0.7, 1.0, 1.3, 2.0 meters from this point meter by meter along the stem up to 8 meters height. After measuring the standing trees they were felled and the diameter was obtained in different positions with a caliper and a tape in the same positions that the non-destructive measures were taken. With the diameters the volume was calculated by section and by individual trees by the Smalian formula for the comparison of methods. Analyzing the measurements of stem diameter and the individual tree volume realizes that the two dendrometers provided measures generally underestimated. However, the Criterion provided the best estimates. For the diameter and individual tree volume the Criterion showed underestimated errors averaging approximately 1 cm (10%), while the RC3H resulted in errors greater than 5 cm (30%) on average.Thus, when measuring observed variables in a non-destructive way with reliability and accuracy, the Criterion showed better results.

FUNÇÃO DE AFILAMENTO E SORTIMENTOS DE MADEIRA PARA Araucaria angustifolia

Taper functions allow determining size classes and volumes of trees with direct application in the planning of technical and economic forest activities. For this purpose, the aim of this study was to describe the taper of the trunk of Araucaria angustifolia (Bertol.) Kuntze in the portion between the ground level and the insertion of the crown of individuals in remnant of native forest. Also tried to fit the regression model to represent relations height/DBH, diameter at the insertion of the crown in function DBH and the development of assortment timber table. Eighty-five trees were measured their diameters and heights relatives using Hohenadl cubed method and the diameter of the insertion crown with Criterion RD 1000 instrument. The taper models were adjusted by regression analysis using polynomial of the 5 th degree, Kozak (1988), Lee et al. (2003) and Sharma and Zhang (2004). The adjusted coefficient of determination (R²aj), the standard error of estimate in percentage (Syx%) and graphical analysis between estimated values in function of observed were used statistics to evaluate the quality of fit and models precision. The model height/DBH and diameter at the insertion point of the crown evidence good fit statistical and precision, allowing its application in activities intended at planning and forest inventories. The flexibility and efficiency of Kozak (1988) model in predicting diameters and volumes until the crown insertion point favors the use and obtain timber assortments of araucaria.

Morfometría de la copa de Araucaria angustifolia en sitios naturales en el sur de Brasil

En el manejo forestal es necesario comprender las relaciones morfometricas para proporcionar informacion sobre las caracteristicas del ajuste de la morfologia de la copa causadas por la competencia, por los recursos ambientales en las comunidades forestales. En este estudio, se analizaron las caracteristicas morfometricas generados con ajuste de ecuacion inter-dimensional para los arboles individuales de Araucaria angustifolia en diferentes sitios del Bosque de Araucaria en el sur de Brasil, para comprobar si hay diferentes respuestas morfologicas en la copa de acuerdo a las diferentes dimensiones del fuste. Para ello, se tomaron muestras de 186 arboles en un enfoque basado en arbol individual en la amplitud de distribucion de diametro del bosque y se midieron sus variables dendrometricas, morfometricas y medidas del incremento en diametro a traves de la cronologia de anchos de anillos. Los resultados del ajuste de los modelos mixtos muestran que la especie difiere en la proporcion de copa entre los sitios. Las ecuaciones fueron capaces de explicar la relacion entre forma y dimension y las variaciones en la morfometria estan relacionadas con la competencia y cambios en el diametro a la altura do pecho, lo que indica que el manejo forestal debe basarse en la diferencias morfometricas para proponer intervenciones silvicolas en el bosque, lo que resulta de manera positiva en aumento de las tasas de crecimiento de los arboles individuales