Treesearch

Taking an ecological approach to management, or ecosystem management, is a developing approach for managing natural resources within the context of large geogaphic scales and over multiple time frames. Recently, the Council on Environmental Quality (CEQ) (IEMTF 1995) defined an ecosystem as "...an interconnected community of living things, including humans, and the physical environment within which they interact." Understanding how humans affect, and are affected by, ecosystems is critical to understanding how these systems function. The CEQ defined the ecosystem approach as "... a method...

The North Central Research Station of the USDA Forest Service is developing a new set of individual tree, diameter growth models to be used as a component of an annual forest inventory system. The criterion for selection of predictor variables for these models is the uncertainty in 5-, 10-, and 20-year diameter growth predictions estimated using Monte Carlo simulations. Particular attention is focused on the uncertainty in the model predictions that can be attributed to five sources of uncertainty: (1) residual variation after model calibration; (2) covariances for parameter estimates; (3)...

Few studies of monogamous canids have addressed regurgitation in the context of extended parental care and alloparental care within family groups. We studied food transfer by regurgitation in a pack of wolves on Ellesmere Island, North West Territories, Canada, during 6 summers from 1988 through 1996. All adult wolves, including yearlings and a post-reproductive female, regurgitated food. Although individuals regurgitated up to five times per bout, the overall ratio of regurgitations per bout was 1.5. Pups were more likely to receive regurgitations (81%) than the breeding female (14%) or...

Cooley gall adelgids, Adelges cooleyi, and round gall adelgids, Adelges abietis, differentially infested 110 half-sib families of Engelmann spruce, Picea engelmannii at 9 study sites in British Columbia. There was a negative genetic correlation (-0.53) between the infestations of the two gall-forming species. Cooley gall abundance exhibited a negative genetic correlation (-0.66) with tree growth, whereas round gall abundance exhibited a positive genetic correlation (0.79) with growth. Heritability (h') of resistance against the adelgids averaged about 0.60 for Cooley galls and 0.20 for...

The three review papers presented in this issue of the Canadian Journal of Forest Research follow a 1-day workshop that was held in Montreal in early January 1997 entitled Functional Aspects of Regeneration In the Boreal Forest in the Context of Sustainable Forest Management. This workshop was held as part of the regeneration working group of Canada's Sustainable Forest Management Network to foster integration and collaboration among scientists in the field of regeneration ecology in the boreal forest. Scientists from Canada, United States, and the Nordic countries attended this workshop....

As the chapters in this book demonstate, forested riparian areas provide many important functions and values, including wildlife habitat, recreation, water, timber production, and cultural resources. The high soil moisture and nutrient availability in these areas make them highly productive sites for plant and animal life, including trees, and this, coupled with the fact that many of these areas have gone unhavested due to difficult terrain and wet soil conditions, makes them a valuable source of wood products. Much of the current debate about riparian areas is focused on the level of...

The Renewable Forest and Rangeland Resources Planning Act of 1978 requires that the USDA Forest Service conduct periodic inventories of forestland in the United States to determine its extent and condition and the volume of standing timber, timber growth, and timber depletions. Five separate Forest Inventory and Analysis (FIA) programs, located in USDA Forest Service research stations, conduct these inventories and publish summary reports for individual states.

The primary objective in developing procedures for annual forest inventories for the north central region of the United States is to establish the capability of producing standard forest inventory and analysis estimates on an annual basis. The inventory system developed to accomplish this objective features several primary functions, including (1) an annual sample of measured field plots, (2) satellite-based remote sensing for stratification into land use and land use change classifications, (3) a database of current and past plot and tree infomation, and (4) models for predicting the...

Theories on allelochemical concentrations in plants are often based upon the relative carbon costs and benefits of multiple metabolic fractions. Tests of these theories often rely on measuring metabolite concentrations, but frequently overlook priorities in carbon partitioning. We conducted a pulse-labeling experiment to follow the partitioning of 14CO2-labeled photosynthate into ten metabolic pools representing growth and maintenance (amino acids, organic acids, lipids plus pigments, protein, residue), defense (phenolic glycosides, methanol: water and acetone-soluble tannins/phenolics),...

Private woodlands have long played an important role in the supply of forest products and environmental benefits throughout the region. The woodlands were originally considered by European settlers to be obstacles to the more important goals of human settlement and agriculture. As recently as the first quarter of this century, for example, forest land grants were given to returning war veterans in northern Ontario. Private ownership did not always lead to sound management. Add to that the uncertainty about harvest on public lands and the increasing demand for growth and it is clear why...