Showing papers in "Revista Arvore in 2010"

Instrumentos legais podem contribuir para a restauração de florestas tropicais biodiversas

Abstract: The failure of most efforts undertaken to restore natural high-diversity tropical forests, like the Atlantic Forest, has resulted in a very intense round of discussions on the science and best-practice of ecological restoration in the state of Sao Paulo, southeastern Brazil. This culminated in the participatory elaboration of a state resolution concerning technical and orientation aspects for restoration activities, which has been reviewed and updated periodically in workshops that bring together more than 200 professionals. The aim of this resolution was to maximize the establishment of biologically viable forests, with plant richness consistent with the reference ecosystem, to ensure the persistence of restored forests and protect native biodiversity. The contributions of this resolution for the improvement and stimulation of restoration actions are evident today. Between 2003 and 2008, when the resolution was heavily discussed, seedling production of native shrubs and trees in the state increased from 13,000,000 (55 nurseries) to 33,000,000 (114 nurseries) per year, and average number of plant species produced in nurseries also increased from 30 to over 80, reflecting the increase of restoration actions. In our view, the existing legal instrument has served well as a mechanism to accompany environmental public policy aimed at protection of the collective interests of society. In particular, it guides and orients the bulk of investments in ecological restoration and enhances the prospects for maximizing the societal benefits that can and should be obtained from restoration activities, including the persistence of biodiversity in human-modified tropical landscapes.

Substratos e temperaturas para testes de germinação e vigor de sementes de Amburana cearensis (Allemão) A.C. Smith

Abstract: Amburana cearensis (Allemao) B.C. Smith is a species native to the Northeast Region of Brazil. It has been increasingly exploited for fine woodworking, perfumery and medicine, therefore the need for studies that can assist in its preservation. The objective of this work was to determine substrate type and optimum temperature for A. cearensis seed germination and vigor tests. The experiment was car ried out in complete randomized design with the treatments distributed in a 5 x 5 factorial scheme, using temperatures (constant of 20, 25, 30 and 35oC and alternate of 20-30oC) and substrates (Germitest paper , sand, vermiculite, bioplant and plantmax) with four replicates of 25 seeds each. The following parameters were analyzed: germination percentage, germination speed, length and dr y mass of seedlings. The optimum temperatur e for A. cearensis seed germination and vigor tests was 35oC, independently of the used substrates. The substrates sand and vermiculite were the most suitable for evaluation of the physiological quality of seeds.

Análise da dinâmica de fragmentos florestais no município de carandaí, mg, para fins de restauração florestal

Abstract: The knowledge on forest patches in rural properties allows the application of a correct environmental administration, promoting their conservation and restoration in degraded areas. By using the softwares SPRING and FRAGSTATS, the landscape was characterized with emphasis on the patches of secondary Seasonal Semidecidual Forest, located in the municipal district of Carandai, MG, and the area around it, considering its evolution from the period of 1984 to 2007. It could be concluded that progressive increase in the total area of native forest occurred due to the appearance of new patches, and the individual area of each patch presented reduction tendency, what provided increase of the edge area, reducing the percentage of each patch which is the core area during the gap of the evaluated time. Despite the advantage of predominance of patches in simple geometric ways, with reduction of the edge effect, the quality of the landscape got threatened because it was predominantly constituted by small patches. The forest patches were still so distant one from the others (more than 200 meters), presenting small gathering tendency (result of the increase of the number of patches), however, still insufficient. Therefore, although the covering of native forest has presented increase of total area, in general, it lost in quality in the gap of the time considered.

Normas jurídicas para a restauração ecológica: uma barreira a mais a dificultar o êxito das iniciativas?

Abstract: RESUMO – A iniciativa de legislar sobre tecnicas de restauracao e recente no Brasil e, de acordo com as informacoes disponiveis, inedita no mundo, havendo controversias sobre a conveniencia dessa legislacao. Na tentativa de trazer luz ao debate, desenvolveu-se analise critica da Resolucao da Secretaria do Meio Ambiente do Estado de Sao Paulo, que normatiza o reflorestamento heterogeneo de areas degradadas. Considerou-se que a norma se baseia em pressupostos que nao encontram respaldo em experimentacao cientifica, uma vez que o entendimento dos processos ecologicos envolvidos na restauracao esta longe de ser suficientemente completo para permitir legislar, com seguranca e detalhamento, sobre o assunto. Adicionalmente, considerouse que nem os profissionais que elaboram projetos nem os que atuam no licenciamento e fiscalizacao detem o conhecimento necessario para aplicar a norma. Entende-se ainda que o rigor das normas cerceia a criatividade e a iniciativa do cientista e do restaurador e, assim, constitui barreira a mais a dificultar a descoberta de solucoes inovadoras e, especialmente, a retardar a expansao das areas restauradas. Do ponto de vista da conservacao da biodiversidade, considera-se que a inducao de demanda comercial de material biologico de especies raras ou ameacadas, prevista na Resolucao, pode colocar em risco a conservacao das populacoes naturais dessas especies, que deveriam ser alvo de programas especificos. Nao parece, em suma, que a instituicao dessa Resolucao tenha contribuido para acelerar o ritmo de ampliacao das areas restauradas e tampouco para aumentar a probabilidade de sucesso das iniciativas de restauracao. Palavras-chave: Legislacao ambiental, Restauracao ecologica e Resolucao SMA 08.

Análise comparativa da produção de serapilheira em fragmentos arbóreos e arbustivos em área de caatinga na FLONA de Açu-RN

Abstract: The litter is the most superficial layer of soil in a forest environment, its composed by Leaves, Twigs, seeds, roots and remains, which together have innumerous importance in establishing and balancing the ecosystem. The purpose of this work was to evaluate the litterfall in two different areas, shrubs and treed, in a preserved area of biom caatinga. This research was carried out in the Acu Nacional Forest - FLONA/ ACU-RN. The FLONA was divided in two different areas, in relation to aspects and vegetation postage, for shrubs and trees. 12 litter collections were made. Each area had 20 wooden traps installed measuring 1.0m X 1.0m X 0.15m (0.15m3), with 1mm nylon mesh, distributed at random in the Flonas area. The material collected was put in paper bags, named and taken to the UERN botanic lab. The material was oven-dried at 70o C during 72h and weighed. The results were expressed in g/m2 and submitted to the analysis of variance and test t (p<0.05). The source results showed that the average annual litterfall was estimated at 2,984.5 Kg/ha, with an estimated 3,384 Kg/ha in tree vegetation and 2,580 kg/ha in shrub vegetation. The litterfall in caatinga bioma was similar to other sources in the caatinga areas. The highest values of litterfall were observed after rainy seasons and the beginning of dry seasons in the researched area.

AVALIAÇÃO DA RETRATIBILIDADE DA MADEIRA DE SETE ESPÉCIES DE Eucalyptus

Abstract: As variacoes na retratibilidade no lenho das arvores sao as principais causas dos defeitos de secagem, como o empenamento e fendilhamento das pecas de madeira. Os tipos de madeira presentes em um tronco estao relacionados com as variacoes dessa importante propriedade fisica. Este trabalho teve como objetivo estudar a retratibilidade da madeira de sete especies de eucaliptos. Os parâmetros de retratibilidade, bem como a sua variacao na direcao radial da medula em direcao a periferia do tronco de sete especies de eucaliptos, foram avaliados de acordo com a Norma brasileira. De modo geral, os resultados indicaram que as especies de eucaliptos estudados possuiam madeira com elevada retratibilidade. A excecao das madeiras de Eucalyptus tereticornis e E. pilularis, as demais especies estudadas apresentaram valores menores de retratibilidade na regiao proxima da medula.

Análise de critérios de qualidade da madeira de eucalipto para produção de celulose kraft

Abstract: Seventy five Eucalyptus wood clones obtained from different geographic regions in Brazil were used for this study. Based on statistical analysis it was demonstrated that an active alkali charge and also wood lignin and extractive contents presented a significant effect on pulping yield. Wood specific gravity did not present a significant effect on pulping yield but affected wood consumption for pulp production (m3wood/ ton pulp). Wood specific gravity, lignin content and extractive content were recommended as criteria to establish wood quality prior to pulping characteristics determination.

Crescimento em diâmetro do tronco das árvores de Eucalyptus grandis W. Hill. ex. Maiden e relação com as variáveis climáticas e fertilização mineral

Abstract: The present work had the objective to evaluate the increment in diameter of Eucalyptus grandis trees for 24 months and its relationship with climatic variables and mineral fertilization The trees were planted at spacing of 3x2 m and fertilized with potassium and sodium (planting, 6 and 12 months) Twenty eucalypt trees were selected by treatment according with the distribution of basal area of the plantation and dendrometer bands were fixed at DBH The results showed a clear effect of climate seasonality on the increment of eucalypt trees, with periods of maximum and minimum growth and a delay period (lag) of 28 days, due to the response of cambial activity to climate variations The application of potassium in relationship of sodium and control promoted greater rate of increment growth of eucalypt trees, with values of 414; 328 and 308 cm, respectively

Análise da arborização urbana de duas cidades da região norte do estado de Mato Grosso

Abstract: The present study aimed to analyze the roadside forestry of Colider and Matupa, two cities of the northern region in the State of Mato Grosso. There were 547 individuals, distributed in 15 botanical families, 21 genera and 21 species. Over 66% of these species are exotic to the Brazilian flora and 33.3% are native. The species most frequent in the evaluated cities were: Licania tomentosa (73,1%), Ficus benjamina (6.6%) and Pachira aquatica (4.2%). In the two cities, more than 85% of the population had a diameter at ground level inferior to 0.4 m and more than 75% of the population had a total height less than 6.0 m, in the two cities. The individuals planted under the electric wiring represented fewer than 50% of the population in the two sampled cities, and the average height of the trees under the wiring was 3.0 m (Matupa) and 4.7 m (Colider). More than 85% of the individuals had presented bifurcation below 1.8 m. The density of trees/km of sidewalk estimated in the evaluated cities varied between 66.2 trees/km (Matupa) and 71.3 tree/km (Colider). The Shannon diversity index estimate was 0.76 (Colider) and 2.24 (Matupa). The width of the streets and recesses allows the planting of medium to large size species. However, urban forestry planning and a definition of criteria and techniques appropriate to the accomplishment of planting and maintenance are essential.

Avaliação do potencial da transposição da serapilheira e do banco de sementes do solo para restauração florestal em áreas degradadas

Abstract: Este estudo teve por objetivo testar a viabilidade da transposicao da serapilheira e do banco de sementes do solo como metodologia de restauracao florestal de areas degradadas. Amostras de 1x1 mdeserapilheira e de solo superficial foram coletadas num fragmento de floresta estacional semidecidual secundaria no campus da Universidade Federal de Vicosa, em Vicosa, MG. As amostras de solo e de serapilheira foram depositadas em canteiros, nos quais o solo superficial (10 cm) foi previamente retirado, no Viveiro de Pesquisas da UFV. Foram comparados tres tratamentos e uma testemunha com cinco repeticoes cada, totalizando 20 amostras. O primeiro tratamento (T1) foi a transposicao apenas da serapilheira, o segundo (T2) apenas do banco de sementes do solo e o terceiro (T3) da serapilheira juntamente com o banco de sementes do solo. Durante um periodo de seis meses, foram registrados 327 individuos de especies arbustivo-arboreas e 864 de especies herbaceas. Entre as especies arbustivo-arboreas, 74% foram pioneiras e 26% de outros grupos ecologicos. A especie arborea mais frequente foi Cecropia hololeuca com 151 individuos. Entre as herbaceas, Oxalis corniculata foi a mais abundante, com 329 individuos. As diferencas de densidade e riqueza de especies entre os tratamentos foram significativas, sendo maior riqueza obtida no tratamento T3 e maiores densidades nos tratamentos T2 e T3. Portanto, conclui-se que a transposicao do banco de sementes e uma metodologia promissora para estimular a restauracao florestal em areas degradadas, sendo mais eficiente quando se utiliza o solo superficial juntamente com a camada de serapilheira.

Amostragem e variabilidade espacial de atributos químicos do solo em área de vegetação natural em regeneração

Abstract: Este trabalho teve como objetivos estimar o numero de subamostras de solo, considerando-se metodos de estatistica classica e geoestatistica, e determinar a variabilidade espacial dos atributos de fertilidade de um Argissolo Vermelho-Amarelo, textura argilosa, em uma area de vegetacao natural em processo de regeneracao, no Municipio de Alegre, ES. Amostras de solo foram coletadas na profundidade de 0-0,20 m, nos pontos de cruzamento de uma malha com intervalos regulares de 10 m, perfazendo um total de 64 pontos. Observouse baixo nivel de fertilidade do solo. Considerando uma variacao de 5% em torno da media no metodo da estatistica classica, necessita-se de maior numero de amostras em relacao a geoestatistica. Todos os atributos quimicos apresentaram dependencia espacial de moderada a alta, com excecao da capacidade efetiva de troca cationica (CTCe), que apresentou efeito pepita puro. O modelo de semivariograma que mais se ajustou aos dados foi o esferico. Os mapas de isolinhas permitiram visualizar a distribuicao espacial diferenciada dos teores dos atributos quimicos do solo.

Análise discriminante de solos sob diferentes usos em área de Mata Atlântica a partir de atributos da matéria orgânica

Abstract: In the mountain region of the State of Rio de Janeiro (Atlantic Rain Forest biome), small farmers practice shifting cultivation in the slash and burn system. In this work, soil surfaces samples (0-15cm) of a Yellow Red Latossolo under five different vegetal coverings (Atlantic Rain Forest, annual culture, coffee, banana and pasture), had been taken in the small farming area of Bom Jardim RJ for soil chemical characterization and carbon content analysis in the different humic fractions. The samples taken under forest and pasture could be clearly isolated from the other groups for the discriminante model created. For the banana, coffee and culture groups, a certain overlapping was observed, indicating a similarity of the soil organic matter attributes between these coverings. The model allowed to correctly classify 88% of the analyzed samples. The fulvic acid (AF), organic carbon (C), total nitrogen (N), and the C/N ratio had been selected by the model, with the fulvic acids having the attribute of higher relative weight. This result suggests that the humic acids fractionation allows the detection of alterations in the soil that are not possible to be identified for the simple determination of the total organic carbon. The discriminate pattern of areas (forest-pasture and banana-coffe-culture) denotes that fertilizer could be related with changes in some important indicator attributes such as fulvic acids.

Germination and vigor of Dimorphandra mollis benth. seeds under different temperatures and substrates

Abstract: The Dimorphandra mollis Benth. - Caesalpiniaceae is a native forest species coming from the Cerrado and Caatinga due to its economical and ecological use, which justifies the studies on seed germination. In this work, germinative performance of D. mollis seeds were studied in different conditions of temperature regime and substrate. The experimental delineation used was completely randomized in factorial 4 x 4 (4 substrates -sand, coconut fiber, vermiculite and paper towel; and 4 temperatures: 25, 30, 35 and 20-30oC), with four replications of 25 seeds each. The following parameters were evaluated: seed moisture content, final germination, first germination count, germination speed index, length and dry matter weight. The best germination and vigor is obtained at 30 and 35oC. The substrates paper towel and vermiculite allow satisfactory germinative performance of seeds, being suitable to evaluate the physiological quality of D. mollis seeds.

Regeneração natural como indicador de recuperação de área degradada a jusante da usina hidrelétrica de Camargos, MG

Abstract: The process of natural regeneration in an area degraded for the construction of the Camargos hydroelectric plant dam, MG, was analyzed 155 months after the planting for its reclamation. The analyses were done in function of the distance to the river, soil compaction and distance of the seed sources. The survey of the natural regeneration was done in plots of 2 x 15m allocated every 10m along three transects (15m width and variable length) parallel to the slope direction. All plants with DBH 10cm were identified and measured in height. Sixty four species of 27 families were found. The adjacent fragment provides a great amount of propagules for the natural regeneration, since many regenerative species in the recovering area were found only in the arboreal stratum of that fragment. A distance of up to 75m to the fragment did not affect the regeneration density, height and diversity, but in the plots taken by the grass Mellinis minutiflora, the density was smaller and the plants higher.

Transposição do banco de sementes do solo como metodologia de restauração florestal de pastagem abandonada em Viçosa, MG

Abstract: This study had as its objective to compare the transposition of the soil seed bank of two successional stages of Seasonal Semideciduous Forest for a Melinis Minutiflora P. Beauv site, in an abandoned pasture of the Mata do Paraiso Forest Reserve, Vicosa, MG. Ten parcels had been placed in each successional site of forest and withdrawals of the center of each parcel sample of 1 m² and 5 cm of superficial depth of soil, being carried afterwards to the abandoned pasture site. Two hundred and thirty one individuals had been registered in the two treatments (initial forest and mature forest), consisting of 31 shrubs and 200 trees. The individuals are distributed by 13 families, 17 kinds and 22 species. The most abundant species had been Vernonia polyanthes, with 108 individuals and Senna multijuga, with 39 individuals. The soil seed bank coming from the site of initial secondary forest (Fi) registered more individuals (120) than the bank coming from the site of the mature forest (Fm), with 111 individuals. The parcels witnesses had been colonized by herbaceous and mainly by the exotic grass Melinis Minutiflora. The number of germinated seeds was only greater in the Fm treatment in the months of july/2008 and january/2009. Significant differences were observed with 1% probability, between the treatments, for the variable wealth of species and density of individuals. The present study showed that it is recommendable and viable to adopt the technique of transposition of the seed bank as a methodology of forest restoration of abandoned pasture.

Uso da função Weibull de três parâmetros em um modelo de distribuição diamétrica para plantios de eucalipto submetidos a desbaste

Abstract: O objetivo deste estudo foi propor um modelo de distribuicao diametrica para povoamentos de eucalipto submetidos ao desbaste, com a inclusao do parâmetro de locacao da funcao Weibull. Essa funcao foi ajustada a dados de 48 parcelas permanentes instaladas em um povoamento desbastado de um clone hibrido de eucalipto (Eucalyptus grandis x Eucalyptus urophylla), localizado na regiao Nordeste do Estado da Bahia, Brasil. A aderencia foi avaliada pelo teste de Kolmogorov-Smirnorv (K-S). A redistribuicao teorica dos diâmetros foi feita a partir de equacoes lineares e nao lineares entre os parâmetros da funcao Weibull em uma idade futura e os parâmetros, em uma idade atual e associados a algumas caracteristicas do povoamento em idades atual e futura. O sistema de equacoes gerado foi avaliado utilizando-se o coeficiente de determinacao ajustado e o coeficiente de correlacao entre frequencias observadas e frequencias estimadas e a analise grafica dos residuos. O sistema proposto resultou em estimativas precisas e consistentes de crescimento por classe de diâmetro.

Efeito da maturação e temperatura na germinação de sementes de Phoenix canariensis hort. ex Chabaud - Arecaceae

Abstract: Phoenix canariensis Hort. ex Chabaud is a palm tree of great ornamental value native to the Canary Islands. Its commercial propagation is done by sexual means and there are only few studies on seed germination under the influence of various factors such as maturation stage and temperatur e. We tried to evaluate the seed germination of P. canariensis using fruits at different maturarion stages under different temperatures. The experiment was arranged in a complete randomized design in a 2 x 5 factorial scheme (two maturation stages and five temperature conditions), with four samples containing 25 seeds each. Brownish and orangish fruits had their pulp removed and their germinative capacity was evaluated by a germination test conducted in BOD incubation chambers under the temperatures of 25oC, 30oC, 35oC, 20-30oC and 25- 35oC, and photoperiod of 16L:8D. Seeds were sown on vermiculite. The results obtained in this experiment led to the conclusion that the alternate temperatur es of 20-30oC were the best for the germination of P. canariensis seeds from mature fruits ( brownish fruits), resulting in 98% of germination.

Leucaena leucocephala (Lam.) de Wit (Fabaceae): INVASORA OU RUDERAL?

Abstract: Exotic species have not been recommended for degraded lands reforestation, since they are reported to invade natural ecosystems in the surrounding areas. Leucena leucocephala, a leguminous N fixing species, was introduced in Brazil and has been widely cultivated, especially to recover degraded soils. The potential of L. leucocephala to expand over the landscape and its persistence in the plant community in the long term was analyzed. A stand planted in 1983 was assessed, which was installed on a rocky soil, immerse in an agricultural matrix, where some native and planted forest patches exists. Over a 200 ha area, eleven distinct patches were surveyed, where all individuals from arboreal species (minimum height 50 cm) were identified and measured (dbh), to verify if the exotic species is expanding over areas where it has not been planted. In the stand where the species was planted, the community structure was assessed on the basis of relative density in size classes to verify if the proportion of the exotic species tends to increase with time, confirming persistence. Since, among the total of 4,599 individuals surveyed, not even a single individual of the species was recorded beyond the limits of the planted stand, invasion of natural ecosystems by Leucena leucocephala was refuted, the species being locally considered as ruderal. Even though a huge number of young individuals of L. leucocephala are regenerating under the planted trees, the relative density of the exotic species in the understorey tends to decrease with time. Apparently, some shade tolerant native species can slowly dominate the community in the future, taking advantage under light competition.

Caracterização morfológica de frutos e sementes e desenvolvimento pós-seminal de Tamarindus indica L. - Leguminosae: caesalpinioideae

Abstract: O tamarindeiro (Tamarindus indica L.) pertence a familia Leguminosae e e uma arvore frutifera, nativa da Africa tropical, de onde se dispersou por todas as regioes tropicais do mundo. A caracterizacao morfologica de frutos e sementes e importante para identificacao das especies, bem como serve de base para estudos que visem a maiores conhecimentos ligados a germinacao e vigor. Este trabalho teve por objetivo descrever a morfologia de frutos, sementes e plântulas, bem como caracterizar o processo germinativo de Tamarindus indica L. Para o estudo do fruto, foram observados tipo, cor, dimensoes, textura e consistencia do pericarpo e deiscencia e numero de sementes por fruto. Os aspectos observados nas sementes foram: cor, dimensoes, textura e consistencia dos tegumentos; e forma, borda, posicao do hilo e de outras estruturas presentes e caracteristicas do embriao. O estadio de plântula foi considerado quando os protofilos ja estavam totalmente formados. Os elementos vegetativos descritos e ilustrados foram radicula, coleto, hipocotilo, cotiledones, epicotilo, protofilos e caule. O fruto de Tamarindus indica e um legume indeiscente medindo aproximadamente 7,3 a 9,2 cm e contendo de 1 a 11 sementes. O eixo embrionario encontra-se inserido nos cotiledones, sendo axial e invaginado. A germinacao da semente e do tipo epigea. A plântula apresenta protofilos compostos de seis a nove pares de foliolos pequenos opostos e glabros.

Avaliação do ajuste das funções weibull e hiperbólica a dados de povoamentos de eucalipto submetidos a desbaste

Abstract: The objective of this study was to evaluate the Weibull and Hyperbolic fitting functions for describing the diametric structure of eucalyptus stands submitted to thinning. The four- and three-parameter functions were fit to data of 48 permanent plots set up in a thinned eucalyptus hybrid clone (Eucalyptus grandis x Eucalyptus urophylla) stand located in northeastern Bahia. The fitting of the two-parameter Weibull function was also evaluated by linear approximation. Adherence was evaluated by the Kolmogorov-Smirnov test. The sum of squares of the residues (SSR) from the different fittings also was compared. All the functions presented adherence to the data (P>0.01). The hyperbolic function presented the smallest sum of squares of the residues and smallest adherence test values. The Weibull function, when fit by linear approximation, presented the largest sum of squares of the residues and significance values for the adherence test.

Physiological and biochemical characterization of the assai palm (Euterpe oleracea Mart.) during seed germination and seedling growth under aerobic and anaerobic conditions

Abstract: Physiological and biochemical aspects of assai palm during seed germination and early seedling growth were investigated. Seeds collected from plants growing in flooded and upland forests were used to determine the influence of normoxic (aerobic) and anoxic (anaerobic) conditions in germination and the initial and average time of development in the roots and shoots. After 75 days, seedlings germinated under normoxia were transferred to trays and submitted to flooding. Seed reserves (lipids, proteins, soluble sugars and starch) were monitored for quiescent and germinated seeds maintained under normoxic and anoxic conditions, as well as after 5, 10 and 20 days of seedling growth. Alcohol dehydrogenase (ADH) activity was quantified in roots and leaves of seedlings without or with flooding (partial and total). Seeds were not able to germinate under anoxia. Different strategies of storage mobilization of lipids, proteins, soluble sugars and starch were observed in seeds of each environment. ADH activity was induced by anoxia, with the highest level observed in the leaves. This study showed that, under normoxic conditions, the best developmental performance of assai palm seeds, from flooded or upland forest areas, during germination was associated with primary metabolites mobilization and seedling flooding tolerance with increased ADH activity. We conclude that the assai palm is well adapted to the anoxic conditions provoked by flooding.

Teores e aporte de nutrientes na serapilheira de Pinus taeda L., e sua relação com a temperatura do ar e pluviosidade

Abstract: The objective of this study was to evaluate the contents and input of nutrients to forest floor in a Pinus taeda L. stand and the relation with rainfall and air temperature, in an area previously occupied with native grass, in Cambara do Sul, RS, through litterfall, evaluated during a three-year period, from the 5th to the 7th year of the stand. Litter was monthly collected in 1.0 m2 (1.0 x 1.0 m) collectors, from April/ 2004 to March/2007. After each collection, litter samples were chemically analyzed for macro and micronutrients. The contents of K, Mg and Cu showed a positive correlation (p < 0,05) with air temperature, while Fe (p< 0.01), Mn and Zn (p < 0,05) showed a negative correlation with this climatic variable. The contents of N and K showed a negative correlation (p < 0.01 e p < 0,05, respectively). The contents of K, Mg and Cu showed a positive correlation (p < 0,05) with rainfall and the contents of S showed a positive correlation (p < 0,05) with air temperature, while the contents of Fe (p < 0.01), Mn and Zn (p < 0,05) showed a negative correlation with this variable.The contents of N and K showed a negative correlation (p < 0.01 and p < 0,05, respectively) with litter amount monthly deposited. Macronutrient mean annual input to soil, through litter deposition, in kg ha-1 was: 18.8 of Ca; 13.0 of N; 3.0 of Mg; 1.6 of K; 1.3 of S and 1.1 of P and for micronutrients the transference, in g ha-1 was: 4,708.3 of Mn; 592.3 of Fe; 74.1 of Zn; 34.0 of B and 7.6 of Cu. The results demonstrate the importantance of keeping the litter over the soil to maintain nutrient cycling.

Estrutura de espécies arbóreas sob efeito de borda em um fragmento de floresta estacional semidecidual em Pernambuco

Abstract: Os fragmentos florestais sao considerados os unicos redutos detentores de biodiversidade do planeta. Conhecer os processos que decorrem apos a fragmentacao, a exemplo da estrutura arborea ocorrente na borda, e de fundamental importância para se proporem medidas conservacionistas. Os objetivos deste trabalho, desenvolvido em uma area de 83,8 ha, localizada no Municipio de Nazare da Mata, PE, foram efetuar o levantamento fitossociologico de especies arboreas adultas sob efeito de borda e verificar a similaridade floristica entre as parcelas. A area amostral foi de 10.000 m2, equivalentes a implantacao de 10 transectos de 10 x 100 m perpendiculares a borda, distribuidos de forma sistematica. Foram amostrados, etiquetados e identificados todos os individuos arboreos com CAP e" 15 cm. Posteriormente, realizaram-se os calculos dos parâmetros fitossociologicos e da similaridade floristica. Neste estudo, amostraram-se 1.238 individuos, pertencentes a 72 taxons, distribuidos em 26 familias botânicas. As especies Campomanesia xanthocarpa, Zanthoxylum rhoifolium e Anadenanthera colubrina apresentaram o maior valor de importância, pois, teoricamente, conseguiram explorar melhor o recurso proporcionado pelo habitat.

CRESCIMENTO DE PLANTAS JOVENS DE NIM-INDIANO (Azadirachta indica A. Juss. - MELIACEAE) SOB DIFERENTES REGIMES HÍDRICOS

Abstract: This work was performed aiming to evaluate the growth of neem seedlings (Azadirachta indica A Juss) under water deficit The experimental design was entirely randomized, with seven treatments (100, 80, 60, 40 and 20% of field capacity, without water and re-watering) The height, number of leaves and stem diameter were analyzed weekly At the end of the experiment, dry matter of the leaves, shoots, roots, root to shoot ratio and biomass allocation in leaf, stem and roots were determined Leaf area, leaf area ratio and specific leaf area were also calculated Water stress reduced the height, number of leaves and shoot diameter in the plants of the several treatments Water stress reduced leaf, stem and root dry matter Only the biomass allocation to leaves was reduced Leaf area was also reduced; however, there were not significant differences for leaf area ratio and specific leaf area The recovery of the re-watering plants was evident by emitting new leaves The results suggest that neem seedlings must be cultivated, in the initial phase of development, under 80% of field capacity, with maximum production

Quantificação de biomassa e estimativa de estoque de carbono em uma capoeira da Zona da Mata Mineira

Abstract: Este estudo teve como objetivo quantificar os estoques de volume, de biomassa total com casca e de carbono em um fragmento de Floresta Estacional Semidecidual em estadio secundario medio (capoeira) na Zona da Mata mineira, no Municipio de Vicosa, MG. Para a conversao de volume em biomassa foram obtidas estimativas de densidade basica das 10 especies de maior valor de importância (VI). O estoque de carbono foi determinado considerando-se que a biomassa seca contem cerca de 50% de carbono. Foram contabilizadas 31 especies arboreas, distribuidas em 29 generos e 21 familias. A biomassa total media das arvores foi de 38,99 t.ha-1, o que correspondeu a um estoque de carbono de 19,50 ± 8,08 tC.ha-1. O valor encontrado foi considerado baixo quando comparado com o de outros estudos. Uma explicacao para isso podem ser as influencias sofridas pelo uso anterior da area e a acao de efeitos de borda na capoeira, o que contribuiu para a menor estocagem de biomassa e de carbono. As estimativas obtidas para a capoeira podem ser usadas como subsidios para a elaboracao de projetos de florestamento/reflorestamento do Mecanismo de Desenvolvimento Limpo.

Propriedades de chapas fabricadas com partículas de madeira de paricá (Schyzolobium amazonicum Huber ex. Ducke) e fibras de coco (Cocos nucifera L.)

Abstract: This work had as its objective to determine the properties of particleboards fabricated with parica particles (Schyzolobium amazonicum Huber ex. Ducke), with increasing proportions of coconut fibers (Coconuts nucifera L.). Boards were fabricated with 6 or 8% of urea-formaldehyde adhesive. Particleboard mean density was equal to 360 kg/m 3 . The addition of coconut fibers didn't affected boards' dimensional stability, higrospicidity, water absorption capability. However it increased its mechanical properties. The addition of 8% of adhesive improved all board properties.

Avaliação técnica e econômica do corte mecanizado de Pinus sp. com Harvester

Abstract: The present study evaluated the operation of the automated cutting of Pinus caribaea hondurensis, in system cut-to-length used Harvester, in the municipal district of Nova Ponte, MG, with base in the productivity and costs of the activity during the initial apprenticeship of it's implantation (5 months), considering the multiple use of the wood. In the technical evaluation calculations were made: Operational income, productivity, mechanical readiness and operational efficiency, while in the economical evaluation it the operational cost and the production costs were calculated. The largest medium productivity was found for month 5 with 22.71m3.he-1, the month that presented the second largest mechanical readiness (95.59%). The largest operational efficiency was found in month 3, at 83.09%. The total operational cost for the period sample of R$ 115.03 per hour of work. The fixed costs corresponded to 28.59%, and it varied by 62.31% of the total costs. The production costs were R$ 5.99.m3-1 produced. In the end productivity increased when the medium volume for trees increased, which the machine possesses a potential for improvement in this operation, and that its production cost is inside that of the expected patterns, for this study.

Estimativa de volume de madeira em plantios de Eucalyptus spp. utilizando dados hiperespectrais e dados topográficos

Abstract: The availability of orbital hyperspectral data has brought new perspectives to both academic and corporative sectors solving demands in forestry science. The main objective of this work was to evaluate the potential of Hyperion EO-1 hyperspectral data to quantify the biophysical timber volume in Eucalyptus spp stands and the effect of hill shading in that quantification. For this, the correlations between spectral data and timber volume were performed following the use of Multiple Linear regression models as the descriptors of the relationships established. The relief effect on the Eucalyptus spp. canopy reflectance was taken into account. The Hyperion EO-1 data were converted to BRF surface values, which were considered the basis of the entire work. The study area was located in the municipality of Capao Bonito (the State of Sao Paulo, Brazil) and included Eucalyptus spp. stands managed by the Votorantim Papel e Celulose company (VCP). Spectral samples were collected in different topographic conditions. In the establishment of the relationship with timber volume, the vegetation indices estimated using hyperspectral data resulted in models with higher R2 when considering the topographic illumination effect, showing higher applicability potential of this data.

Arborização urbana em quadras de diferentes padrões construtivos na cidade de Jataí

Abstract: The study aimed to comparatively evaluate the quality and quantity of tree planting in the urban perimeter of Jatai city, Brazilian central region. To make comparisons possible, a georeferenced map of all blocks in the city was used. These were partitioned into three categories by the building parameters, denominated 1. high/medium, 2. simple and 3. precarious patterns. For each category the urban arborization of 60 blocks, randomly selected on the map, independent of the quarter was evaluated. The survey detected 114 different species and 1953 trees, distributed into 1853 exotic and 100 native species. Oiti (Licania tomentosa) was the more common species used in arborization, with 31% of all trees surveyed. The tree average number was significantly higher in high/medium and simple patterns than the precarious pattern. When considering the sidewalk position, the high/medium pattern showed the greatest adjustments in planting. Medium and small tree weight species and palm trees were more abundant in high/medium patterns. This study showed evident differences in urban arborization between categories compared to the streets of the Jatai city. Thus, the results can allow and technically instruct the prefecture, as well as the entire population of this city about forms of better planting, choices of appropriate seedlings and maintenance until maturity.

Serapilheira e teores de nutrientes em argissolo sob diferentes manejos no norte do Piauí

Abstract: This work aimed to evaluate litter deposition and quantify contents of N, P, K, Ca and Mg in agroforest systems six (AFS6) and ten (AFS10) years after implantation, in three-year old ecological based systems (ES3), slash-and-burn agriculture (SBA) and native forest (NF), all located in Esperantina, northern region of Piaui, Brazil. Collections were carried out in the wet and dry seasons of 2007. The litter was separated into leaves and branches and weighted to estimate the deposition on the soil. The highest leaf depositions were found in NF (3.8 Mg ha-1), in the dry season, whereas for branches, in the AFS10 (2.2 Mg ha-1), in the wet season. AFS showed the highest nutrient contents in the litter fractions, and, among them the N concentration was higher than the others, in both seasons. The estimate transfer of nutrients by the litter followed the sequence N>Ca>K>P>Mg. The values for litter deposition and contents and input of nutrients in the AFS systems show the contribution of the agroforest management to soil quality and the economic sustainability of the system.