Treesearch

This paper presents initial investigations of a new approach to monitor ecosystem processes in complex terrain on large scales. Metabolic processes in mountainous ecosystems are poorly represented in current ecosystem monitoring campaigns because the methods used for monitoring metabolism at the ecosystem scale (e.g., eddy covariance) require flat study sites. Our goal was to investigate the potential for using nocturnal down-valley winds (cold air drainage) for monitoring ecosystem processes in mountainous terrain from two perspectives: measurements of the isotopic composition of ecosystem...

Mountain meadows in the Pacific Northwest, as in much of western North America, have experienced recent and rapid invasion by conifers. Changes in climate, cessation of sheep grazing, and long-term suppression of wildfire likely contribute to the observed replacement of meadow by forest. Faced by gradual loss of these habitats, land managers in the western Cascades of Oregon are using tree removal and prescribed burning as tools for restoration. However, these efforts have been undertaken with limited understanding of the historical role of fire in these meadow ecosystems, of the range of...

The historical range of variability (HRV) in landscape structure and composition created by natural disturbance can serve as a general guide for evaluating ecological conditions of managed landscapes. HRV approaches to evaluating landscapes have been based on age classes or developmental stages, which may obscure variation in live and dead stand structure. Developing the HRV of stand structural characteristics would improve the ecological resolution of this coarse-filter approach to ecosystem assessment. We investigated HRV in live and dead wood biomass in the regional landscape of the...

High-value, large-volume utilization of forest thinning materials from U.S. national forests is a potentially important contributor to sustainable forest health. This study demonstrated the utilization of wood chips produced from thinnings for the production of thermomechanical pulp (TMP). Both whole-log chips (primarily from small-diameter logs, tops, and reject logs) and sawmill "residue" chips from a HewsawTM system (Mantyharju, Finland) were evaluated. The residue chips produced in this study were substituted for a TMP mill's standard residue chips up to about 50 percent. The whole-log...

We studied the effects of six green-tree retention levels and patterns on the diets of northern flying squirrels (Glaucomys sabrinus), Townsend's chipmunks (Tamias townsendii), Siskiyou chipmunks (T. siskiyou), western red-backed voles (Myodes calijamicus), and southern red-backed voles (Myodes gapperi) using fecal pellet analysis. These rodents are truffle spore dispersers and prey for forest predators such as the northern spotted owl (Strix occidentalis caurina). Pretreatment diets showed differences in truffle and plant consumption among genera. Tree harvesting, especially in the...

Two of the most fundamental questions in forest ecosystem management are: (1) What are the consequences of different forest management practices? and (2) How do they vary with spatial and temporal scale? The forest management controversies of the 1990s in the Pacific Northwest revolved around these questions and led to major new forest polices in the region for federal and state lands, as well as considerable modification of forest polices for private forest lands. In the Coast Range Physiographic Province in Oregon, for example, new and separate policies across all ownerships federal,...

To inform the U.S. Fish and Wildlife Service decision whether or not to list polar bears as threatened under the Endangered Species Act (ESA), we forecast the status of the world's polar bear (Ursus maritimus) populations 45, 75 and 100 years into the future. We applied the best available information about predicted changes in sea ice in the 21st century to current knowledge of polar bear populations and their ecological relationships to the sea ice to understand how the range-wide population of polar bears might change. We combined the world's 19 polar bear subpopulations into 4 ecological...

An inventory was conducted of old forests on state trust lands in Eastern Washington managed by the Washington State Department of Natural Resources (DNR), in response to legislative direction (ESSB 6384, Section 189,2006). This inventory was conducted with guidance from an independent science panel, chaired by Jerry Franklin of the University of Washington. As directed by the Legislature, the inventory was focused on the dry ponderosa pine-dominated forests but included other forest types as well. For the purposes of this inventory, forests were stratified by ecological and environmental...

Stream temperature is a complex function of energy inputs including solar radiation and latent and sensible heat transfer. In streams where groundwater inputs are significant, energy input through advection can also be an important control on stream temperature. For an individual stream reach, models of stream temperature can take advantage of direct measurement or estimation of these energy inputs for a given river channel environment. Understanding spatial patterns of stream temperature at a landscape scale requires predicting how this environment varies through space, and under different...

Site Index (SI), a key inventory parameter, is traditionally estimated by using costly and laborious field assessments of tree height and age. The increasing availability of reliable information on stand initiation timing and extent of planted, even-aged stands maintained in digital databases suggests that information on the height of dominant trees suffices for assessing SI. Light detection and ranging (LiDAR) is a technology proven capable of providing reliable estimates of tree height even at the individual-tree level. A rigorous evaluation of LiDAR-enabled SI estimation performed on...