Recursos de colección

Biblioteca Digital do IPB (53.442 recursos)

A Biblioteca Digital do IPB, tem por objectivo divulgar e permitir o livre acesso à produção científica produzida pela comunidade académica, promovendo a integração, partilha e a visibilidade da informação científica e garantindo a preservação da memória intelectual do Instituto Politécnico de Bragança.

ARN - Publicações em Proceedings Indexadas ao ISI

Mostrando recursos 1 - 5 de 5

  1. Biomass equations for Castanea sativa high forest in the Northwest of Portugal

    Patrício, Maria do Sameiro; Monteiro, Maria do Loreto; Tomé, Margarida
    There is considerable interest today in estimating the biomass of trees and forests for practical forestry issues, sustainable management, carbon and nutrient flux and other scientific purposes. For these reasons, aboveground biomass was studied in Castanea sativa high forest stands located in the Northwest of Portugal. The most widely used procedure for stand biomass evaluation is the regression estimation method, in which the stand biomass is predicted through the sum of the predicted biomass of individual trees. In this study, thirty-four old sweet chestnut trees, located in three stands, were felled, measured and weighted to evaluate the aboveground biomass by components. Several linear and nonlinear equations were fitted...
    - 31-may-2018

  2. Management models evaluation of a castanea sativa coppice in the Northeast of Portugal

    Patrício, Maria do Sameiro; Monteiro, Maria do Loreto; Nunes, Luís; Mesquita, Susana; Beito, Sónia; Casado, José; Guerra, Hélia
    In a chestnut high forest converted into coppice, 4 permanent plots were established in 1994. These plots are being managed according to the silvicultural models proposed by Bourgeois (1992) and adapted to our conditions. The treatments are: T1 = Model 1: small dimensions; T2 = Model 2: medium dimensions; T3 = Model 3: Large dimensions; Control = coppice without intervention. In 2003, a 2nd thinning was applied in order to select the more straight and cylindrical shoots without defects. The principal dendrometrical parameters (such as: number of stumps per hectare; number of shoots per hectare; mean total height of the shoots; dominant height of the shoots; mean DBH...
    - 31-may-2018

  3. Chestnut high forest stands: biometrical study in the north of Portugal

    Nunes, Luís; Monteiro, Maria do Loreto; Patrício, Maria do Sameiro; Alpuim, Teresa; Martins, Lucílio
    Growing sweet chestnut (Castanea sativa) in high forest stands is a lucrative investment. Wood with medium and large dimensions can attain interesting profitability levels. Furthermore, forest producers are interested of new on this species and decision criteria for the best management are needed for landowners. So, accuracy is very important when evaluating volume in standing trees. Based on regression theory, it is developed predicting equations of wood volume as a function of tree variables easily measured (fast and cheap), such as diameter at breast height (DBH) and tree total height (h). Variable selection in volume equations was based on a stepwise modified procedure (linear models) and using generalized-F...
    - 31-may-2018

  4. Temporal analysis of sweet chestnut decline in northeastern Portugal using geostatistical tools

    Castro, João Paulo; Azevedo, João; Martins, Luís
    The rising demand for sweet chestnut (Castanea sativa) in Portugal and elsewhere in Europe has led to more intensive management practices to increase nut production. This intensification has potentially increased the widespread of ink and chestnut blight diseases, causing decline in sweet chestnut orchards health and production and limiting the establishment of new planted areas. In this study we estimated chestnut decline along the last twenty years (1986 to 2006) in the northern part of Portugal using 1986, 1995 and 2006 aerial photography to quantify the damage at the tree level within fixed sample plots according to a categorical scale....
    - 25-may-2018

  5. Landscape change in a mountainous area in Northeastern Portugal: implications for management

    Moreira, César; Castro, João Paulo; Azevedo, João
    In this paper we analyzed changes in landscape composition and structure over the 1958-2005 period in the França parish (Bragança, northeastern Portugal). Agriculture decreased from 22% to 5% of the area of study. Forests and shrublands became the dominant land uses occupying together 73% of the area of study in 2005. Structurally the landscape became more homogeneous. We speculate that the types of change observed and the tendency for their magnification in the near future will have functional effects on this landscape, namely the creation of condition for the occurrence of catastrophic disturbance events such as wildfires.
    - 10-ene-2018

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