Treesearch

The purpose of this report is to improve understanding of the complex sociopolitical processes related to resource management and to help structure management response to conflict and contentiousness, misunderstanding among participants, and failed citizen-agency interactions. Public acceptance is essential to every resource management decision public agencies must make. Regardless of the issue—forest health, fuels management, riparian restoration, recreation impacts, or threatened and endangered species—the political environment surrounding most decisions is never about just single...

Old-growth forests supply many important values, including critical habitat for some wildlife species. These forests are most useful for some wildlife species when they exist in large blocks. But many areas dedicated to old-growth values on federal lands are fragmented by patches of second-growth forests planted after timber harvest. These second-growth forests are often dense stands of Douglas-fir with little structural diversity.When--and if--these conifer plantations develop the characteristics of old-growth forests, then large parts of the forested landscape will function as complex,...

Spatially explicit information on the species composition and structure of forest vegetation is needed at broad spatial scales for natural resource policy analysis and ecological research. We present a method for predictive vegetation mapping that applies direct gradient analysis and nearest-neighbor imputation to ascribe detailed ground attributes of vegetation to each pixel in a digital landscape map. The gradient nearest neighbor method integrates vegetation measurements from regional grids of field plots, mapped environmental data, and Landsat Thematic Mapper (TM) imagery. In the...

We describe regional patterns of variation in dead wood across 20 million ha of upland forests of all ownerships in Oregon and Washington, based on an analysis of data on snags and down wood collected on over 16,000 field plots. Current patterns of dead wood are highly variable and complex. The strongest differences were among nine habitats that reflect strong regional gradients in physical environment and ecosystem processes. Mean snag density was lowest in the drier habitats east of the Cascade crest and greatest at higher elevations, ranging from 0.8/ha to 37.2/ha. The mean volume of...

This handbook describes quick, effective methods for documenting change in vegetation and soil through repeat photography. It is published in two parts: field procedures in part A and concepts and office analysis in part B. Topics may be effects of logging, change in wildlife habitat, livestock grazing impacts, or stream channel reaction to land management. Land managers, foresters, ranchers, wildlife biologists, and land owners may find this monitoring system useful. Part A discusses three critical elements: (1) maps to find the sampling location and maps of the photo monitoring layout;...

PCR recombination describes a process of in vitro chimera formation from non-identical templates. The key requirements of this process is the inclusion of two partially homologous templates in one reaction, a condition met when amplifying any locus from polyploid organisms and members of multigene families from diploid organisms. Because polyploids possess two or more divergent genomes ("homoeologues") in a common nucleus, intergenic chimeras can form during the PCR amplification of any gene. Here we report a high frequency of PCR-induced recombination for four low-copy genes from allotetra...

Meeting the needs of expanding human populations has changed land use worldwide and presented a biodiversity crisis. Emerging related concerns are threats to native species from homogenization of world flora and the spread of exotic species by human activities (Soule 1990, United States Congress, Office of Technology Assessment 1993, Wilcove and others 1998, Soule and Terbogh 1999). The benefits to people of domestication and spread of food and fiber plants such as wheat, corn, potatoes, and cotton are well known (Diamond 1998). Catastrophes caused by introduced diseases such as chestnut...

This field guide is designed for geologists floating the approximately 80 kilometers (50 miles) of the Deschutes River from the Pelton-Round Butte Dam Complex west of Madras to Maupin, Oregon. The first section of the guide is a geologic timeline tracing the formation of the units that compose the canyon walls and the incision of the present canyon. The second section discusses the hydrology, morphology, and formation of the present river channel. The third section is a river log, describing sights and stops for a 3-day floating field excursion.

Tsuga heterophylla (western hemlock), a fire-sensitive, late-successional tree species, is an important component of old-growth forests in the Pacific Northwest, USA. In the Oregon Coast Range, however, T. heterophylla occurs at low densities in or is completely absent from many conifer stands. We used a cellular automata-based simulation model to explore the influences of the fire regime and gap disturbances on T. heterophylla dynamics at a landscape scale. The abundance of T. heterophylla in the simulated landscape was particularly sensitive to variation in fire return interval and fire...

It has long been known that genomes vary over a remarkable range of sizes in both plants (Bennett, Cox, and Leitch 1997) and animals (Gregory 2001). It also has become evident that across the broad phylogenetic sweep, genome size may be correlated with intron size (Deutsch and Long 1999; Vinogradov 1999; McLysaght et al. 2000), suggesting that some component of genome size evolution takes place within genes. Examples include humans and pufferfish (Fugu), where comparisons of 199 introns in 22 orthologous genes showed that introns in Fugu were on average eight times as small as those in...