Mostrando recursos 1 - 20 de 1.096

  1. Estimating leaf area index in Southeast Alaska: a comparison of two techniques.

    Carolyn A Eckrich; Elizabeth A Flaherty; Merav Ben-David
    The relationship between canopy structure and light transmission to the forest floor is of particular interest for studying the effects of succession, timber harvest, and silviculture prescriptions on understory plants and trees. Indirect measurements of leaf area index (LAI) estimated using gap fraction analysis with linear and hemispheric sensors have been commonly used to assess radiation interception by the canopy, although the two methods often yield inconsistent results. We compared simultaneously obtained measurements of LAI from a linear ceptometer and digital hemispheric photography in 21 forest stands on Prince of Wales Island, Alaska. We assessed the relationship between these estimates...

  2. Intercropped silviculture systems, a key to achieving soil fungal community management in eucalyptus plantations.

    Caio T C C Rachid; Fabiano C Balieiro; Eduardo S Fonseca; Raquel Silva Peixoto; Guilherme M Chaer; James M Tiedje; Alexandre S Rosado
    Fungi are ubiquitous and important contributors to soil nutrient cycling, playing a vital role in C, N and P turnover, with many fungi having direct beneficial relationships with plants. However, the factors that modulate the soil fungal community are poorly understood. We studied the degree to which the composition of tree species affected the soil fungal community structure and diversity by pyrosequencing the 28S rRNA gene in soil DNA. We were also interested in whether intercropping (mixed plantation of two plant species) could be used to select fungal species. More than 50,000 high quality sequences were analyzed from three treatments:...

  3. Breeding Bird Community Continues to Colonize Riparian Buffers Ten Years after Harvest.

    Scott F Pearson; Jack Giovanini; Jay E Jones; Andrew J Kroll
    Riparian ecosystems integrate aquatic and terrestrial communities and often contain unique assemblages of flora and fauna. Retention of forested buffers along riparian habitats is a commonly employed practice to reduce potential negative effects of land use on aquatic systems. However, very few studies have examined long-term population and community responses to buffers, leading to considerable uncertainty about effectiveness of this practice for achieving conservation and management outcomes. We examined short- (1-2 years) and long-term (~10 years) avian community responses (occupancy and abundance) to riparian buffer prescriptions to clearcut logging silvicultural practices in the Pacific Northwest USA. We used a Before-After-Control-Impact...

  4. Logging affects fledgling sex ratios and baseline corticosterone in a forest songbird.

    Rhiannon Leshyk; Erica Nol; Dawn M Burke; Gary Burness
    Silviculture (logging) creates a disturbance to forested environments. The degree to which forests are modified depends on the logging prescription and forest stand characteristics. In this study we compared the effects of two methods of group-selection ("moderate" and "heavy") silviculture (GSS) and undisturbed reference stands on stress and offspring sex ratios of a forest interior species, the Ovenbird (Seiurus aurocapilla), in Algonquin Provincial Park, Canada. Blood samples were taken from nestlings for corticosterone and molecular sexing. We found that logging creates a disturbance that is stressful for nestling Ovenbirds, as illustrated by elevated baseline corticosterone in cut sites. Ovenbirds nesting...

  5. Regeneration of a coastal pine (Pinus thunbergii Parl.) forest 11 years after thinning, Niigata, Japan.

    Jiaojun Zhu; Yutaka Gonda; Lizhong Yu; Fengqin Li; Qiaoling Yan; Yirong Sun
    To examine the effects of thinning intensity on wind vulnerability and regeneration in a coastal pine (Pinus thunbergii) forest, thinning with intensities of 20%, 30% and 50% was conducted in December 1997; there was an unthinned treatment as the control (total 8 stands). We re-measured the permanent sites to assess the regeneration characteristics 11 years after thinning. In the 50% thinned stand, seedlings aged from 2 to 10 years exhibited the highest pine seedling density and growth. The age composition ranged from 1-3 years with densities of 9.9 and 5.1 seedlings m(-2) in 30% and 20% thinned stands; only 1-year-old...

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    Galopin, Gilles; MAUGET, Jean-Claude; Morel, Philippe
    International audience

  7. Integrating conservation objectives into forest management: coppice management and forest habitats in Natura 2000 sites

    Mairota P; Buckley P; Suchomel C; Heinsoo K; Verheyen K; Hédl R; Terzuolo PG; Sindaco R; Carpanelli A
    Most forest habitats, as defined and listed for their nature conservation importance in the Habitats Directive of the European Union and in the Bern Convention, result from centuries of human intervention. This paper explores the scope for, and the attitudes towards coppicing in Natura 2000 sites in some of the EU28 countries where coppice was historically one of the most important traditional silvicultural systems. A questionnaire survey was circulated to experts involved with Natura 2000 sites and case studies were conducted in Belgium, the Czech Republic, Estonia, Germany, Italy and the United Kingdom, to investigate attitudes to coppice silviculture within...

  8. Zoning of the Russian Federation territory based on forest management and forest use intensity

    A. A. Маrtynyuk; V. M. Sidorenkov; E. V. Doroshchenkova; Е. М. Sidorenkova; U. G. Zakharov
    Over extended periods issues of forest management intensification are important in all aspects of Russian forest sector development. Sufficient research has been done in silviculture, forest planning and forest economics to address forest management intensification targets. Systems of our national territory forest management and forest economics zoning due to specifics of timber processing and forest area infrastructure have been developed. Despite sufficient available experience in sustainable forest management so far intensification issues were addressed due to development of new woodlands without proper consideration of forest regeneration and sustainable forest management operations. It resulted in forest resource depletion and unfavorable substitution...

  9. ARAUCARIA CLONAL FORESTRY: TYPES OF CUTTINGS AND MOTHER TREE SEX IN FIELD SURVIVAL AND GROWTH

    Ivar Wendling; Carlos André Stuepp; Katia Christina Zuffellato-Ribas
    Araucaria angustifolia (Bert.) O Kuntze (Paraná pine or Araucaria) is a potential forestry native species for Brazilian silviculture. However, a number of challenges and technical restraints persist, hindering its silvicultural expansion, among which are the lack of cloning technologies of superior genetic materials and their assessment under field conditions. Thus, we evaluated the potential use of araucaria plants derived from cuttings and seeds for timber production, by assessing field survival, growth and strobilus production using cuttings from male and female plants, collected from different positions, compared with those produced by sexual reproduction. Clones of male and female trees from different...

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    Prévosto, B.; Gavinet, J.; Monnier, Y.; Corbani, A.; Fernandez, C.
    International audience

  11. Natural regeneration of the shrub-tree stratum in areas of caatinga at the Seridó Ecological Station, RN, Brazil

    Marcelo Silva de Lucena; Josuel Arcanjo da Silva; Allyson Rocha Alves
    The objective of this study was to evaluate the composition and floristic similarity, regeneration origin and the influence of silviculture systems on the diversity and absolute density of regeneration of the shrub-tree stratum in two areas of Caatinga. The first area is in the Seridó Ecological Station and the second is on Pedro Candido Farm, in the city of Serra Negra do Norte, in the Seridó region of RN, Brazil. In each area, 16 subplots of 25m2 were delimited and individuals with a base circumference ≤ 6 cm and a height > 0.5 m were included in the study. The...

  12. Growth dynamics of rubber tree clones in northwestern Minas Gerais, Brazil

    Maria Isabela da Costa Terra; Flora Ferreira Camargo; Renato Luiz Grisi Macedo; Bruna Anair Souto Dias; Nelson Venturin; Erick Martins Nieri
    ABSTRACT: This study aimed to evaluate the growth of rubber tree clones ( Hevea brasiliensis (Willd.exA.Juss.) Müll. Arg.) in the Northwest region of Minas Gerais, Brazil. Randomized blocks, constituted of three treatments (rubber tree clones) and four repetitions were used, and evaluated as plots subdivided in time. Subplots represent the evaluations carried out at the ages 62, 77, 87, 99, 113 and 128 months after planting. It was evaluated survival, stem circumference and total plant height. Current annual increment and average annual increment of circumference and also the number of trees fit for rubber tapping were calculated. Results obtained indicate...

  13. O USO DE UM SISTEMA DE INFORMAÇÕES GEOGRÁFICAS NA DETERMINAÇÃO DA APTIDÃO AGRÍCOLA DAS TERRAS DE PARTE DO SETOR LESTE DA BACIA DO RIO SERIDÓ, PB

    Maria de Fátima Fernandes; Marx Prestes Barbosa; Miguel José da Silva
    RESUMO Com esta pesquisa, desenvolveu-se uma metodologia baseada em técnicas de sensoriamento remoto e sistemas de informações geográficas, com o objetivo de gerar um banco de dados que permita a determinação da aptidão agrícola das terras de parte do setor leste da bacia do Rio Seridó, no Estado da Paraíba. Utilizando-se o sistema de informações geográficas, SGI versão 2.5E, foi criada a estruturação de uma base de dados georreferenciada. Conforme o mapa de aptidão obtido, três classes foram definidas como: 3(bc) - aptidão restrita para lavouras com os níveis de manejo B e C; 5(n) - restrita para pastagem natural...

  14. GENETIC VARIATION FOR THE SILVICULTURE CARACTER IN THREE ARBOREOUS SPECIES OF THE SOUTH BOLSÃO REGION IN MATO GROSSO DO SUL STATE, BRASIL

    Helena de Cássia Brassaloti Otsubo; Mario Luiz Teixeira de Moraes; Marcela Aparecida de Moraes; Maria José Neto; Miguel Luiz Menezes Freitas; Reginaldo Brito da Costa; Marcos Deon Vilela de Resende; Alexandre Magno Sebbenn
    The present study aimed at evaluating genetically the best progenies of Myracrodruon urundeuva, Astronium fraxinifolium e Terminalia argentea from Selvíria, MS, concerning their growing traits. The progeny test was performed by outlining randomized blocks with 28 treatments, 4 repetitions and 10 plants per plot in single rows at 1.5 x 3.0 spacing. At 14 years of age, the progenies were evaluated concerning the traits: height (ALT, m); diameter of the height (DAP, cm); average diameter of the top (DMC, cm); trunk shape (FT), grade scale, ranging from 1 to 5, and survival (SOB, %). The average herdability for the traits...

  15. Even-Aged vs. Uneven-Aged Silviculture: Implications for Multifunctional Management of Southern Pine Ecosystems

    Ajay Sharma; Kimberly K. Bohn; Shibu Jose; Puneet Dwivedi
    We evaluated even- and uneven-aged silvicultural options for slash pine (Pinus elliottii Engelm.) using empirical data and the Forest Vegetation Simulator (FVS) model. Data were collected from a mature unthinned slash pine plantation in a flatwoods site in Florida, and used to simulate six scenarios of even- and uneven-aged silvicultural regimes applied to slash pine stands, including a no-action option. These alternative silvicultural regimes were evaluated for multiple benefits including timber production, carbon storage and stand structural diversity over a period of 100 years. None of the silvicultural regimes maximized all the benefits. While even-aged management options were more efficient...

  16. Assessment of Soil Protection to Support Forest Planning: an Experience in Southern Italy

    Fabrizio Ferretti; Paolo Cantiani; Isabella De Meo; Alessandro Paletto

    Aim of study: to support landscape planning when soil-erosion control and water cycle regulation represent relevant issues for forest management. A methodological approach - based on simplified index – is proposed in order to assess the protective efficacy of forests on soils (indirect protection). This method is aimed at supporting technicians who are requested to define the most suitable management guidelines and silvicultural treatments.
    Area of study: Southern Apennines (Alto Agri district – Basilicata Region - Italy), where a landscape planning experimentation was implemented.
    Material and Methods: The data to estimate the parameters used for the simplified index calculation are...

  17. Silviculture conditions and wood properties of Samanea saman and Enterolobium cyclocarpum in 19-year-old mixed plantations

    M.F. Obando; R. Moya

    Aim of study: The objective of this work is to examine wood properties of a mixed plantation of Samanea saman and Enterolobium cyclocarpum, combined with native species of Costa Rica.

    Area of study: Mixed plantation in dry tropical zone of Costa Rica.

    Material and Methods: It was measured by total diameter, heartwood, bark thickness, several physical wood properties (green density, specific gravity, volumetric, tangential and radial shrinkage and moisture content) and wood color.

    Main results: The largest of this diameter are reached when S. saman is planted with E. cyclocarpum, E. cyclocarpum and Swietenia macrophylla and Simarouba glauca. Meanwhile the largest total diameter...

  18. Análise da Influência do Uso e Ocupação do Solo na Qualidade da Água de Duas Sub-Bacias Hidrográficas do Município de Caxias do Sul

    Renata Cornelli; Vania Elisabete Schneider; Taison Anderson Bortolin; Gisele Cemin; Geise Macedo dos Santos
    O uso e ocupação do solo podem influenciar diretamente na qualidade e na disponibilidade dos recursos hídricos, seja pela urbanização acelerada, pela supressão da vegetação ou uso agrícola. Os impactos podem variar em função do uso, aporte de carga orgânica, nutrientes, contaminantes metálicos e o arraste de sedimentos comprometendo a qualidade e o equilíbrio dos ecossistemas aquáticos. Este trabalho objetivou avaliar a influência do uso e ocupação dos solos sobre a qualidade da água das bacias hidrográficas dos Rios Piaí e Tega, em Caxias do Sul-RS. Avaliou-se para tal os Índices de Qualidade da Água (IQA) e de Toxicidade (IT)...

  19. A Review of the Characteristics of Small-Leaved Lime (Tilia cordata Mill.) and Their Implications for Silviculture in a Changing Climate

    Tanguy De Jaegere; Sebastian Hein; Hugues Claessens
    Tilia cordata Mill. is a minor European broadleaved species with a wide but scattered distribution. Given its scarcity and low value in the wood market, it has received little attention from researchers and forest managers. This review summarizes the main aspects of T. cordata ecology and growth. Its main limiting factor is its need for warm summer temperatures to ensure successful seed production. It has a height growth pattern relatively similar to that of Acer pseudoplatanus L., with a slight delay in the early stages. Yield tables report great productivity, especially in eastern Europe. T. cordata used to be a...

  20. Árvores de boa semente: silvicultura, preservação da natureza e agricultura na Primeira República

    Roberta Barros Meira; Mariluci Neis Carelli
    Este artigo é uma análise do pensamento em prol da silvicultura e da preservação das florestas brasileiras e no seu papel na organização e feitura do Serviço Florestal no Brasil durante a Primeira República.  Foram analisados também a forte vinculação dessas ideias com os setores agrícolas.  Nesse sentido, é um estudo sobre a valorização da ciência no Brasil e sua inserção tanto na agricultura como na exploração das riquezas naturais, mas especificamente, as florestas.  Aborda com esse intuito o pensamento de cientistas, agricultores e estadistas reproduzidos em uma documentação que envolve o Ministério da Agricultura, revistas científicas e agrícolas, folhetos...

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