Treesearch

The magnitude of hydraulic redistribution of soil water by roots and its impact on soil water balance were estimated by monitoring time courses of soil water status and multiple depths and root sap flow under drought conditions in a dry ponderosa pine (Pinus ponderosa Dougl. ex Laws) ecosystem and in a moist Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) ecosystem. The fate of deurerated water applied to small plots to create a strong horizontal soil water potential gradient was also monitored to assess the potential for horizontal redistribution of water and utilization of redistribute...

Solid wood is important to the construction, manufacturing, and shipping segments of the U.S. economy. Nearly all new houses are built with wood, and wood building products are used in the construction of nonresidential buildings, and in the upkeep and improvement of existing structures. Solid wood is used extensively to produce and transport manufactured products. It also provides a renewable energy source for industrial, commercial, and residential applications. In 1998, 19.6 billion cubic feet, roundwood equivalent, of all timber products were consumed in the United States, down...

Because breeding imposes strong artificial selection for a narrow suite of economically important traits, genetic variation is reduced in seedlings derived from operational seed orchards. Both quantitative genetics theory and studies of allozyme variation show that seed orchards contain most of the genetic diversity found in natural populations, although low-frequency alleles are often absent from seed orchard populations. Because plantations established with seed orchard seed are frequently maintained for only a single generation, they do not need to preserve the low-frequency alleles...

We provide background documentation for the Pacific Northwest Research Station’s Wood Compatibility Initiative, a 5-year multidisciplinary research effort that began in response to 1997 Congressional direction. This problem analysis was the initial effort to examine the state of knowledge regarding compatibility between wood production and other values and to develop a framework for directing a research initiative (Wood Compatibility Initiative) that examines the central question: Can we as a society produce wood commodities and other forest values in an environmentally acceptable and...

An extensive forest inventory was conducted to estimate the amount and distribution of coarse woody debris (CWD) on 5.6 million ac of woodlands in California that are outside of national forests and reserved areas. Woodlands consist primarily of oak (Quercus spp.) types and are defined as forestland incapable of producing commercial quantities of traditional forest products because of adverse site and tree morphophysiology. Approximately 671 million ft3of CWD were estimated to occur over the study area. Almost 3 million ac of woodland (52% of the sampled area) were estimated to have no...

The primary objective of the Forest Health Monitoring indicator project is to develop models that use the composition of epiphytic lichen communities to detect and monitor air quality in forests. The designs of existing air quality monitoring networks in California do not provide adequate representation of rural areas to assess impacts to forests. This article is designed to provide readers with a brief synopsis of air quality monitoring in north-central California, an overview of current air quality issues in the area, and an introduction to plans for monitoring air quality in forests...

During 5 years of research (1994-98) in support of the Northwest Forest Plan (NWFP), Pacific Northwest Research Station scientists and their collaborators have made significant progress in both validating some of the NWFP’s major assumptions and providing research that sets the stage for further evolution of the plan. Studies have provided new information in the areas of wildlife conservation and population viability, aquatic conservation measures, adaptive management, the socioeconomic dimension, ecological processes and functions, landscape-scale issues, and stand-development strategies....

Through review of relevant economic principles and judicial precedent, a case is made that public-land recreation enterprises are analogous to traditionally recognized public utilities. Given the historical concern over the societal value of recreation and associated pricing issues, public-land management policies failing to acknowledge these utility-like characteristics and a subsequent agency regulatory responsibility are shown to be deficient. Existing institutional barriers, however, sometimes limit the options available to agency managers. Eight strategies for performance enhancement...

The Coarse Wood Dynamics Model (CWDM) analyzes the dynamics (fall, fragmentation, and decomposition) of Douglas-fir (Pseudotsuga menziesii) and western hemlock (Tsuga heterophylla) snags and down logs in forested ecosystems of the western Cascades of Oregon and Washington. The model predicts snag fall, height loss and decay, and log decay at 5-year intervals for a period of 300 years. Snags either fall whole or in parts, creating down logs. Snags also decay from a hard to soft condition. Logs decay more slowly than snags, from sound to decayed conditions, and eventually disappear into the...

This survey identifies and defines innovative contracting mechanisms developed in the Forest Service Pacific Northwest Region and northern California. A survey of nine case studies reveals that several new mechanisms have facilitated ecosystem management, quality jobs, and administrative efficiencies, but at times innovation was hampered by Forest Service institutional structures and downsizing.