Rodrigo Geroni Mendes Nascimento

Distribution of total height, transverse area and individual volume for Araucaria angustifolia (Bert.) O. Kuntze.

This study aimed to test probability density functions for the distribution of variables total height, transverse area and individual volume, considering three different class intervals. Data were obtained from the measurement of diameter (DBH) and total height and from estimation of the individual volume of 338 pine trees in a fragment of Mixed Ombrophylous Forest with an area of 15.24 ha, which is located in Jardim Botânico campus of UFPR, Curitiba-PR. Ten functions were fitted, including commonly used models for diameter distribution as well as other recently developed models applied to forest science. Selection criteria included Kolmogorov-Smirnov adherence test, standard error of estimate in percentage and adjusted coefficient of determination. Three class intervals were used as obtained by Sturges, Dixon & Kronmal, and Velleman criteria. The Normal function for variable height, and the Weber function for distribution of transverse area and individual volume, provided the best fit, considering the three class intervals adopted. The models fitted better for larger size class intervals as obtained by Sturges rule.

Distribuição espacial de um fragmento de Floresta Ombrófila Mista Montana

The objective of this research was to analyze the spatial distribution of a Mixed Ombrophylus Forest fragment, as well as of three species pertaining to distinct successional groups belonging to the same, by the Ripleys K function. The data came from a census carried out in a fragment located in the Campus Botanical Garden, UFPR, Curitiba - PR, Brazil, where all trees with DBH above 10cm were georeferenced. One plot with 4 ha was used for the analysis of the spatial distribution of the forest and individually for the species of Araucaria angustifolia (Bertol.) O. Kuntze, Casearia Sylvestris Sw. and Cedrela fissilis Vell. The spatial relationship between species, as well as the spatial relationship between diameter classes of the same were also analyzed. The forest showed a random spatial distribution, however, the three selected species showed an aggregate spatial distribution when analyzed individually. The Casearia Sylvestris presented an attraction relationship with Araucaria angustifolia and Cedrela fissilis, and these trees in turn, were related to repulsion between them. The spatial relationship between DBH classes of Araucaria angustifolia was attraction between individuals of smaller classes with larger individuals. This result reflects the form of seed dispersal of species, where regeneration occurs in the proximity to the parental trees. For the Casearia Sylvestris and Cedrela fissilis, aggregation occurred only between the smaller individuals.

Comparison of methods for estimating heights from complete stem analysis data for Pinus taeda .

The objective of this research was to compare actual heights at known ages with those estimated by the methods proposed by Graves (1906), Carmean (1972), Lenhart (1972), Newberry (1978), and the Ratio and Graphic methods, in order to identify the most accurate one for Pinus taeda from Southern Brazil. That way, six trees aged at least 11 years were used. Cross-sections with 5 cm thickness were collected at heights of 0.10 meters, 0.70 meters, 1.30 meters and so on at every 1 meter along the bole. True height growth for a given age was measured on the section itself by dividing it in two parts along the pith and looking for the exact point where the true annual height growth took place. The accuracy analyses were based on residuals between true heights and those estimated by the tested methods for each age. For this analysis, the relative mean deviation (D % ), relative mean absolute deviation (AbsD % ), standard deviation of differences (S d ) and sum of squared relative residuals (SSRR) were calculated. These 4 statistics evaluated together, allowed for the identification of the most accurate method for every age. Complementarily, the non paired t 0.05 test for data was applied to evaluate whether the residuals from each method were significant or not. The results of the analysis indicated that Carmean (1972) and Lenhart (1972) were identical owing to the fact that they estimated the same height value for sections where there was only one growth ring finishing in the same section. This situation occurred for most of the results in this current study. It was concluded that Carmean (1972) and Lenhart (1972) were the best methods for estimating height growth because both produced non-significant residuals for the majority of the trees studied.

Efeito da árvore marginal nos estimadores populacionais obtidos por métodos de amostragem de área variável

Nesta pesquisa, objetivou-se avaliar o efeito da arvore marginal nos estimadores populacionais obtidos pelos metodos de amostragem de Bitterlich (1948), Prodan (1968) e Strand (1958). A base de dados foi um censo realizado em fragmento de Floresta Ombrofila Mista Montana situado no Campus III da UFPR, Curitiba - PR. Todas as arvores com DAP ≥ 10 cm foram medidas, identificadas, georreferenciadas, e consideradas como possiveis centros das unidades amostrais dos metodos. De todas as arvores, 185 foram sorteadas, aleatoriamente, como inicio dos pontos amostrais para a estimativa de N.ha-1, G.ha-1 e V.ha-1 para os tres tratamentos distintos: sem a influencia da arvore marginal, contagem de meia arvore e contagem da arvore marginal corrigida pelo Fator P de Pellico Netto (1994). Independente do metodo e do tratamento utilizado ocorreu superestimativa do N.ha-1. Para a estimativa da area basal, bem como do volume por hectare, o metodo de Bitterlich apresentou os melhores resultados, seguido de Strand e Prodan, respectivamente. A aplicacao do fator P nas arvores marginais nao melhorou expressivamente os estimadores populacionais a ponto de se diferenciar satisfatoriamente da estimativa gerada com as arvores marginais, contadas como meia arvore ou sem a sua influencia.

Comparação dos parâmetros fitossociológicos entre três estratos de um fragmento de floresta ombrófila mista

Phytosociological studies based on sampling have been very common in the last 20 years, however, they are rarely carried out using complete enumeration of trees (census). This research compare the phytossociological parameters between three different strata from a remnant of Ombrophylous Mixed Forest (OMF), which are: OMF Montana, Border OMF Montana and OMF Alluvial. The area of 13.71 was topographically divided in blocks of 50 x 50 meters for a better control of the 100% forest inventory (census). All trees with CBH (circumference measured at 1,30 m above ground) ≥ 31,5 centimeters were measured, georeferencied, numbered, painted at DBH and identified at species level. In the strata OMF Montana the species with the highest Value of Coverage (VC) was Araucaria angustifolia, with 30.6%, followed by Casearia sylvestris with 25.8%. In the Border OMF Montana the species that succeeded Araucaria angustifolia (29.0%) was Gochnatia polymorpha with 27.2% of VC. The third strata, OMF Alluvial, presented as predominant species Schinus terebinthifolius (55,5%), followed by Sebastiania commersoniana (27,7%), both characteristics of alluvial environments. In the three strata there was prevalence of secondary pioneer species, proving that the area is in a secondary stage of ecological succession due to past exploratory process.

Sampling system for estimating woody debris in an urban mixed tropical forest

Woody debris, defined as standing and downed deadwood, consists in an essential component of the forest carbon stock. However, few studies have been carried out to get an efficient and accurate sampling procedure for estimating it. This work proposes two methodologies to estimate the woody debris volume in a Brazilian mixed tropical forest: 1) two-stage systematic sampling, using a mixed methodology, in which the Strands method is applied to standing dead trees and stumps, and line intercept sampling is used to fallen trees and branches; and 2) ratio estimate of the sum of cross-sectional areas of deadwood pieces and forest basal area, aiming to obtain the total woody debris volume indirectly in the natural forest. Conversions for biomass and carbon stocks were made applying the mean basic density on the estimates of deadwood volumes. Both methodologies are accurate for woody debris volume estimates, with a sampling error equal to 16.1% (methodology 1) and 5.7% (methodology 2), at a 95% probability level. Thus, the methodology 2 has potential to be used in strategic forest inventories of woody debris, such as in National Forest Inventories, due to increasing importance of its quantification in all forest ecosystems.

Projeção da Estrutura Diamétrica de Grupos Ecológicos em uma Floresta Ombrófila Mista

This study aimed to evaluate the ecological and successional aspects of a subtropical forest fragment by projection of the diameter distribution of different ecological groups, using transition matrix model. Based on measurements of 2009 and 2012 of all trees above 10 cm of DBH, projection of the diameter distribution as well as analysis of forest dynamic were made for three species groups: Pioneer; Non Pioneers, and the whole forest. Simulations of the dynamics of the groups were made until 2027 after method validation. The projection method was adherent in all cases, with higher precision when using the 5cm class interval. The analysis made indicated a gradual substitution tendency of the pioneer species, suggesting a successional advance in the forest fragment under study, as well as an efficiency of the projection method for dynamics analysis of the ecological groups studied.