A deciduous tree has broad, flat leaves which it sheds in the autumn. Its seeds are enclosed in ordinary cases as for example, the oak, birch and walnut. Timber from deciduous trees is said to be 'hardwood'. It can be seen, therefore, that the term 'softwood' and 'hardwood' apply to the family or type of tree and do not necessarily indicate the density of the wood. That is why balsa, the lighte...

1 Key Laboratory of Plant Genetic Improvement of Northwest China, College of Horticulture, Northwest Agricultural and Forest University, Yangling, Shaanxi, China 2 Department of Applied Biology, University of Helsinki, Helsinki, Finland 3 Laboratory of Tropical Crop Improvement, Division of Crop Biotechnics, Katholieke University Leuven, Leuven, Belgium 4 Institut de Recherche pour le développe...

Dendroctonus frontalis, the southern pine beetle (SPB), is a highly destructive species of bark beetle that inhabits pine forests in the southern United States and parts of Central America. @6D In natural pine forests, the ecological role of the SPB presumably is to hasten the demise of weak or damaged trees, perhaps creating kindling for fires that contribute positively to the long-term health...

Most tropical forests are government-owned, with timber being harvested under concession agreements awarded to private logging companies. Those agreements tend to be short-term harvesting licenses lasting no more than one to a few years. In the absence of regulation, loggers can be expected to ignore the negative environmental impacts of logging, as they derive little or no financial gain from ...

THINNING overdense stands to improve growth rate of trees is one way in which the nation's supply of merchantable timber can be increased significantly.' In the Pacific Northwest alone, several million acres of such dense precommercial stands would benefit from thinning. Two basic methods are used to thin dense forest stands—felling unwanted trees with saws or killing them with chemicals. Econo...

The responsibility for protecting U.S. agriculture from pests and diseases is assigned by the Federal Plant Pest Act (FPPA) to the Animal and Plant Health Inspection Service (APHIS) of the Department of Agriculture. The Plant Protection Act (Title 7 U.S.C. Sections 7701 et seq.) gives Aphis statutory authority over genetically modified organisms (GMO), in effect assigning to APHIS a related res...

In this paper, we describe the TIMBER XML database system implemented at University of Michigan. TIMBER was one of the first native XML database systems, designed from the ground up to store and query semi-structured data. A distinctive principle of TIMBER is its algebraic underpinning. Central contributions of the TIMBER project include: (1) tree algebras that capture the structural nature of ...

Management activities alter the structure of many tropical forest stands which can be expected to influence the magnitude of canopy water fluxes. The objectives of this study were to determine throughfall, stemflow and rainfall interception in differently managed forest stands, and to relate the observed pattern of rainfall partitioning to stand structural characteristics. The study was conduct...

Timber management directly influences the population dynamics of tree species, like Copaifera spp. (copaíba), which provide oil-resin with ecological and economic importance. The aim of this study was to evaluate the structure and population dynamics of Copaifera in unmanaged and managed stands by reduced-impact logging (RIL) in eastern Amazon in Pará state, Brazil. Based on a stem map of the s...

The aim of this study was to analyze the occurrence of butt rot damage to Norway spruce in different parts of southern Finland and to quantify the associated loss of quality. The data used in the study are from the 9th National Forest Inventory and consist of 5998 sample plots and 8007 spruce sample trees of saw-timber size. To predict the probability of damage to stands and trees, logistic reg...