DENDROECOLOGICAL ANALYSIS OF Ocotea pulchella AND Nectandra maegapotamica ON TWO SITES NEAR SANTA MARIA, RIO GRANDE DO SUL (BRAZIL)

AbstractA dendroecological analysis of Ocotea pulchella (n=5) and Nectandra megapotamica (n=2) was conducted on two sites near Santa Maria, Rio Grande do Sul (Brazil). Growth data were obtained by tree-ring analysis of stem disks at breast height (1,3 m). Radial increment was measured on four perpendicular radii using the 'LINTAB' measuring device. Mean growth sequences were standardised to highlight short-term variation. Air temperature, precipitation and compound climatic quantities like evapotranspiration and water balance were used to find indications about the climate-growth relationship. Variation of wood increment and climatic variation was compared by using sensitivity and correlation analysis. Some factors as regional climate (seasonality) in general, wood structure of the species and cross-dating of individual radii indicate that annual growth banding is likely. Due to a lacking correspondence between water balance and ring width indexes, water stress does not seem to be the synchronising factor of radial increment. In view of the measured periodical radial increments, it becomes evident that for Ocotea goal-diameters of 50-60 cm at breast height cannot be obtained in a short time without thinning. No medium-term growth release was found for both species.Keywords: Dendroecology; annual rings; water balance; Ocotea pulchella; Nectandra megapotamica. ResumoAnálise dendroecológica de Ocotea pulchella e Nectandra megapotamica em dois sítios próximos a Santa Maria, Rio Grande do Sul/Brasil. A análise dendroecológica de Ocotea pulchella (n = 5) e Nectandra megapotamica (n = 2) foi realizada em dois sítios próximos ao município de Santa Maria, RS/Brasil. Os dados de crescimento das 2 espécies foram obtidos através da análise dos anéis de crescimento de amostras do lenho da altura do DAP (1,30 m). Os incrementos radiais foram mensurados em 4 orientações radiais e perpendiculares, utilizando a mesa de mensuração 'LINTAB'. O histórico do crescimento médio em diâmetro do tronco das árvores foi estandardizado para a análise da variação de curto prazo. A temperatura do ar, precipitação e outros componentes climáticos (ex.: evapotranspiração, balanço de água) foram utilizados para analisar as correlações existentes com o crescimento das árvores. As variações do incremento radial e das variações climáticas foram comparadas utilizando-se a análise de sensitividade e de correlação. Alguns fatores climáticos sazonais regionais, a estrutura do lenho das espécies e a datação cruzada dos raios das amostras dos lenhos comprovam que os anéis de crescimento demarcam incrementos anuais. Devido à inexistência de relação entre o balanço de água e os índices de largura dos anéis de crescimento nas árvores das 2 espécies, o estresse hídrico não parece desempenhar um fator crítico de sincronização dos incrementos radiais do tronco.Palavras-chave:     Dendroecologia; anéis de crescimento anuais; balanço de água; Ocotea pulchella; Nectandra megapotamica.A dendroecological analysis of Ocotea pulchella (n=5) and Nectandra megapotamica (n=2) was conducted on two sites near Santa Maria, Rio Grande do Sul (Brazil). Growth data were obtained by tree-ring analysis of stem disks at breast height (1,3 m). Radial increment was measured on four perpendicular radii using the 'LINTAB' measuring device. Mean growth sequences were standardised to highlight short-term variation. Air temperature, precipitation and compound climatic quantities like evapotranspiration and water balance were used to find indications about the climate-growth relationship. Variation of wood increment and climatic variation was compared by using sensitivity and correlation analysis. Some factors as regional climate (seasonality) in general, wood structure of the species and cross-dating of individual radii indicate that annual growth banding is likely. Due to a lacking correspondence between water balance and ring width indexes, water stress does not seem to be the synchronising factor of radial increment. In view of the measured periodical radial increments, it becomes evident that for Ocotea goal-diameters of 50-60 cm at breast height cannot be obtained in a short time without thinning. No medium-term growth release was found for both species.

Estrutura e regeneração de Bertholletia excelsa Bonpl. em castanhais nativos da Amazônia

This work was developed with the objective of comparing the diameter structure and natural regeneration indicators of Brazil nut groves and correlates them to the forest successional stage, seed collection intensity and logging. Data were collected from 54 hectares in Caracaraí (Roraima state) and Itaúba (Mato Grosso state). Frequency distributions were compared by measures of central tendency, variability, form and adherence by Kolmogorov-Smirnov Test. Natural regeneration was correlated with environmental variables, seed collection intensity and fauna activity by Spearman correlation coeficient and Kruskal-Wallis. The Brazil nut groves presented different diametric structures, which can be attributed to differences in young individuals in the smaller diametric classes. The higher density of juveniles in canopy gaps and the lack of a significant correlation between seed collection intensity and natural regeneration indicate that canopy openings from logging could have been the major impact factor in the natural regeneration establishment and in Brazil nut grove rejuvenation.O trabalho foi desenvolvido com o objetivo de comparar a estrutura diamétrica e os indicadores de regeneração natural em castanhais nativos e correlacioná-los a fase de desenvolvimento da floresta, a intensidade de coleta de sementes e a exploração madeireira. Os dados foram coletados em 54 hectares nos municípios de Caracaraí (RR) e Itaúba (MT). As distribuições de freqüência diamétricas foram comparadas por medidas de tendência central, variabilidade, forma e aderência por Kolmogorov-Smirnov. A regeneração natural foi correlacionada às variáveis ecológicas, intensidade de coleta e a atividade da fauna pelo Coeficiente de Correlação de Spearman e pelo teste de Kolmogorov-Smirnov. Não foi observada correlação entre a taxa de coleta e os indicadores de regeneração e, apesar da alta intensidade de coleta de sementes, observou-se um número satisfatório de indivíduos jovens, indicando que a abertura de clareiras pela exploração florestal pode ter sido o fator de maior impacto no estabelecimento da regeneração natural e no rejuvenescimento dos castanhai

Utilização de variáveis dummy em equações de volume para Acacia mearnsii De Wild.

This work was accomplished with the objective of selecting a volume equation with the use of dummy variables for Acacia mearnsii De Wild, in the area of Central Depression of Rio Grande do Sul. In the study there were sampled 750 trees distributed in three places, in ages varying from 3,5 to 7,5 years. The statistical parameters indicated the Stoate Model as the one with the best precision. The fit of this equation with the use of dummy variables was shown to be efficient because it allowed to identify tree growth differences among places, which suggest that the fit of volume equations should be separate to each place, as a way of minimizing errors of volume estimation.Este trabalho foi realizado com o objetivo de selecionar uma equação de volume, com o uso de variáveis dummy para povoamentos de Acacia mearnsii De Wild, na região da Depressão Central no Rio Grande do Sul. No estudo, foram amostradas 750 árvores, distribuídas proporcionalmente em três locais, em idades variando de 3,5 a 7,5 anos. Os parâmetros estatísticos utilizados indicaram o modelo de Stoate como o de melhor precisão. O ajuste dessa equação com a utilização de variáveis dummy se mostrou eficiente, pois permitiu identificar diferenças de crescimento das árvores entre locais, o que indicou a necessidade de ajustar equações de volume em separado para cada local minimizando erros de estimativa de volume

DIAMETER STRUCTURE AND ITS RELATIONSHIP WITH FRUIT AND SEED PRODUCTION IN A NATIVE BRAZIL NUT GROVE IN MATO GROSSO

The study aimed to evaluate the annual variation in fruits and seed productivity of Brazil nut trees and to determine the association between diameter structure and fruit/seed productivity in a semi-deciduous seasonal forest undergoing logging in Mato Grosso, Brazil. Data were collected in two permanent plots (300 m x 300 m) spaced 3.5 km apart. All trees (n = 279) with diameter at breast height (DBH) ≥ 10 cm were tagged and productivity was monitored from October to February during each of the five harvest seasons between 2012 and 2017. Associations between seed dry weight (SDW) per tree and DBH, crown position, crown shape and fruit number were established using stepwise regression analysis. The model based on DBH was a good predictor of seed production and revealed that SDW tree-1 increased by 1.3 kg on average for every 10 cm increase in DBH. Trees reached the reproductive phase with DBH < 50 cm. Characteristics and mean SDW values of the diameter classes were: 10 cm ≤ DBH < 30 cm - dominated/suppressed trees/malformed crowns (0.12 kg tree-1year-1); 30 cm ≤ DBH < 70 cm - dominant/co-dominant/good crown shape (1.23 kg tree-1year-1); DBH ≥ 70 cm - dominant/co-dominant/well-formed crowns (4.8 kg tree-1year-1). DBH explained 34% of the variation in the mean SDW. Our results are important for the sustainable management of the study stands, allowing the assessment of current and future yields of Brazil nuts for the purpose of improving the economy of forest-dependent communities and associated enterprises

Equações Hipsométricas e Volumétricas para Acacia mangium Willd em RoraimaHypsometric And Volumetric Equations for Acacia mangium Willd In Roraima

A Acacia mangium é a espécie florestal mais plantada no Estado de Roraima, sendo necessário estudos que visem ao desenvolvimento de sistemas silviculturais adaptados às condições locais. Este trabalho foi desenvolvido com o objetivo de selecionar equações de relação hipsométrica e de volume para A. mangium em área de savana no estado de Roraima. Foram utilizadas 701 árvores amostras localizadas em três fazendas e duas regiões. Foram testadas 8 equações hipsométricas e 5 volumétricas. Nas condições estudadas, a equação hipsométrica selecionada apresentou um R2aj = 0,62 e a equação logaritmizada de Spurr se mostrou a mais adequada para estimar a o volume total (R2aj =0,98) e comercial com casca (R2aj =0,58).Abstract As the Acacia Mangium is the most planted forestry species in Roraima, it is necessary to carry out studies that help to develop silvicultural systems adapted to the local conditions. This work intends to select equations of hypsometric relations and volume for A. Mangium in an area of Savannah, in the state of Roraima. For this study, 701 samples of trees located in three farms and two regions of the state were analyzed, and 8 hypsometric and 5 volumetric equations were tested. According to the analysis, the selected hypsometric equation presented a R2aj = 0,62 and the Spurr logarithm equation proved to be the most adequate to estimate the total volume (R2aj = 0,98) and the commercial value with bark (R2aj = 0,58

GROWTH AND ENERGY QUALITY OF EUCALYPTUS WOOD IN DIFFERENT CROP-LIVESTOCK-FOREST SPATIAL ARRANGEMENTS

The aim of the present study was to assess the growth and energetic properties of genetic material of eucalyptus grown in several integrated crop-livestock system spatial arrangements in Barra-do-Garças City (MT). The genetic material of 76-month old Eucalyptus spp from eight spatial arrangements were assessed according to the following properties: diameter, height and volume growth, mortality rate, dry matter yield, sapwood to heartwood ratio, form factor, bark volume, basic density, superior calorific value, ash content, volatile matter, fixed carbon and trunk energy. Data analysis was performed by adjusting growth function, test for model identity and parameters equality and ANOVA tests to Scott-Knott’s mean clustering test. Eucalyptus grandis x E. urophylla clones from recorded the highest energy efficiency due to their high yield volume, which was decisive to determine estimated energy available per tree and cropland area. Growth, stem shape and basic density varied among, and within, the same genetic materials, depending on their respective spatial arrangement. However, solid biomass properties (high calorific value, ash content, fixed carbon and volatile matter) remained stable

COMPARAÇÃO GRÁFICA ENTRE CURVAS DE ÍNDICE DE SÍTIO PARA Pinus elliottii E Pinus taeda DESENVOLVIDAS NO SUL DO BRASIL

Este trabalho teve como objetivos estudar o crescimento em altura dominante para Pinus elliottii e Pinus taeda, mediante comparações entre as curvas de índice de sítio construídas para algumas regiões do estado do Rio Grande do Sul e outros Estados da Federação. Essas comparações indicaram que as curvas feitas por Tonini (2000) para as regiões da Serra do Sudeste e Litoral no estado do Rio Grande do Sul, não apresentaram o mesmo desenvolvimento em relação às curvas feitas por Scolforo e Machado (1988), para os estados do Paraná e Santa Catarina; Brasil (1989a), para a região de Passo Fundo RS, Marcolin (1990), para o Segundo Planalto Paranaense e Selle (1993), para a região de Cambará do Sul. No entanto, o comportamento em relação às curvas de índice de sítio feitas por Brasil (1989b), para a região de São Francisco de Paula mostraram-se semelhantes, havendo somente uma diferença de nível entre estas

EUCALIPYTUS LITTER CONTRIBUTION TO THE INTEGRATED CROP-LIVESTOCK SYSTEM

The aim of this study is to assess eucalyptus litter and nutrient deposition on a monthly basis, at the age 47 to 58 years, in integrated eucalyptus with crop system (ICF), eucalyptus with livestock (ILF) and eucalyptus monoculture (F). Integration system data were compared through t test and compared to eucalyptus monoculture through ANAVA and Duncan test, at 5% probability level. Annual litter deposition reached 0.63 t ha-1 year in CFI, 0.43 t ha-1 year in LFI and 6.34 t ha-1 year in the monoculture system. The total and fractioned litter deposition in integration systems (0.19 to 0.26 kg.m-2) was significantly different from the monoculture system (0.63 kg.m-2) at collector area level, however, integration systems did not differ from one another at hectare level. The same trend was observed for nutrient stock in different compartments of the assessed litter. Regardless of the production system, the leaf fraction was the most representative factor in litter composition, which was followed by branches and bark. Nutrient content was similar among the tested treatments. Finally, nutrient stock was higher in the monoculture system; the highest nutritional contribution was observed in CFI between the assessed integration systems

Morfologia da copa para avaliar o espaço vital de quatro espécies nativas da Amazônia

This work aimed at defining guidelines for thinning of four native species in pure stands, in Roraima State: Brazil nut tree (Bertholletia excelsa), Andiroba (Carapa guianensis), Ipê-roxo (Tabebuia avellanedae), and Jatobá (Hymenea courbaril). Analyses were made on the relations between main crown morphometric index, and diameter and height growth of these species. Eighty-seven trees were measured, and data taken are: diameter at breast height, total height, crown insertion height and crown diameter. Crown parameters analysis showed diameter and crown area superiority of Brazil nut, which indicates its need of a proper initial spacing and bigger growing space. However, Brazil nut crown was less efficient to maintain the same mean annual diameter increment.O objetivo deste trabalho foi o de definir diretrizes para o desbaste de quatro espécies nativas: a castanha-do-pará ou castanheira-do-brasil (Bertholletia excelsa), a andiroba (Carapa guianensis), o ipê-roxo (Tabebuia avellanedae) e o jatobá (Hymenaea courbaril), plantadas em plantios homogêneos no Estado de Roraima. Foi feita a análise das relações entre os principais índices morfométricos da copa e o crescimento em diâmetro e altura; para isso foram medidos o diâmetro à altura do peito, altura total, altura de inserção e diâmetro da copa de 87 árvores. Na análise dos parâmetros de copa, a castanheira-do-brasil demonstrou superioridade em diâmetro e área, o que indica que essa espécie necessita de um maior espaço vital e maiores espaçamentos iniciais; no entanto, sua copa foi menos eficiente em manter um mesmo incremento médio anual em diâmetro

PHENOLOGY OF ANDIROBA( Carapa guianensis , Aubl., MELIACEAE) IN SOUTH OF RORAIMA STATE

O presente estudo foi realizado com o objetivo de estudar o padr\ue3o fenol\uf3gico da esp\ue9cie arb\uf3rea Carapa guianensis , Aubl., em floresta natural localizada no sul do estado de Roraima, procurando relacionar a frequ\ueancia de ocorr\ueancia das fenofases \ue0s condi\ue7\uf5es pluviom\ue9tricas do per\uedodo. Para o levantamento fenol\uf3gico foram selecionados 20 indiv\uedduos adultos localizados em uma parcela permanente de 9 ha. As observa\ue7\uf5es fenol\uf3gicas ocorreram quinzenalmente de fevereiro de 2006 a fevereiro de 2009, registrando-se a presen\ue7a ou aus\ueancia dos eventos de flora\ue7\ue3o, frutifica\ue7\ue3o e mudan\ue7a foliar para cada \ue1rvore. Para analisar a influ\ueancia da precipita\ue7\ue3o na fenologia da esp\ue9cie foi utilizado o coeficiente de correla\ue7\ue3o de Spearman e, para estimar a sincronia dos eventos fenol\uf3gico utilizou-se o \uedndice de sincronia da popula\ue7\ue3o (Z). A flora\ue7\ue3o da andiroba mostrou-se subanual, sincr\uf4nica e correlacionada negativamente com precipita\ue7\ue3o no per\uedodo do evento fenol\uf3gico. Foram observados dois ciclos de flora\ue7\ue3o, sendo um longo com inicio em outubro, estendendo-se para o ano seguinte, por um per\uedodo m\ue9dio de 9 meses, e um curto com dura\ue7\ue3o de dois meses (julho a agosto). A frutifica\ue7\ue3o \ue9 anual, longa e sincr\uf4nica, e correlacionou-se positivamente com a precipita\ue7\ue3o. A \ue9poca ideal para a coleta dos frutos maduros no local estudado \ue9 durante o per\uedodo chuvoso, que compreende abril a julho. A emiss\ue3o de folhas ocorreu de forma cont\uednua e n\ue3o se correlacionou com a precipita\ue7\ue3o. Observou-se uma maior propor\ue7\ue3o de indiv\uedduos perdendo folhas, entre os meses de agosto a novembro, que caracterizam um per\uedodo de transi\ue7\ue3o entre a \ue9poca seca e chuvosa, com sens\uedvel redu\ue7\ue3o de precipita\ue7\ue3o.This work was carried out in order to study the phenological pattern of Andiroba in natural forest located in the south of Roraima state, seeking to relate the frequency of phenol-phases occurrence with the rain rate in this period. For the phenological survey 20 adult trees were selected in a permanent sample plot of 9ha. The visits to phenological observations occurred fortnightly from February 2006 to December 2008, recording the presence or absence of flowering, fruiting and leaf change events for each tree. The Spearman correlation was used for analyzing the influence of rainfall on phenology and, the index of synchrony of population (Z) was used for estimating the synchrony of phenological events. The flowering of Andiroba showed to be sub-annual, synchronous and was negatively correlated with the rainfall during the phenological event. Two cycles of flowering were observed: a long one from October until next year, which lasts about nine months, and a short one lasting two months, from July to August. The fruiting is annual, long and synchronous and it was positively correlated with rainfall. The ideal time for collecting ripe fruits at the study site is during the rainy time, that is, from April to July. The leaf flushing was continuous and did not correlate with the rainfall. It was noticed a higher proportion of trees falling leaves between August and November, which characterizes a period of transition between the dry and the rainy period with sensitive reduction of rainfalls