Treesearch

This report updates data and comparisons from previous reports (Curtis and others 2000, Curtis 2008) on a series of precommercial thinning and yield trials in high-elevation true fir–hemlock stands, using data from the 12 replicates for which 20-year data are now available. The stands were varying mixtures of Pacific silver fir (Abies amabilis (Douglas ex Loudon) Douglas ex Forbes), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and noble fir (Abies procera Rehder). Trends noted in the 2008 report continue. Increment in top height was somewhat reduced at wide spacings. Volume increment...

We monitored coarse woody debris dynamics and natural tree regeneration over a 14-year period after the 1991 Warner Creek Fire, a 3631-ha (8,972-ac) mixed severity fire in the western Cascade Range of Oregon. Rates for tree mortality in the fire, postfire mortality, snag fall, and snag fragmentation all showed distinct patterns by tree diameter and species, with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) more likely to survive a fire, and to remain standing as a snag, than other common tree species. Natural seedling regeneration was abundant, rapid, and highly variable in space....

Indigenous populations are projected to face disproportionate impacts as a result of climate change in comparison to nonindigenous populations. For this reason, many American Indian and Alaska Native tribes are identifying and implementing culturally appropriate strategies to assess climate impacts and adapt to projected changes. Traditional ecological knowledge (TEK), as the indigenous knowledge system is called, has the potential to play a central role in both indigenous and nonindigenous climate change initiatives. The detection of environmental changes, the development of strategies to...

Light detection and ranging (LiDAR), also known as airborne laser scanning, is a rapidly emerging technology for remote sensing. Used to help map, monitor, and assess natural resources, LiDAR data were first embraced by forestry professionals in Scandinavia as a tool for conducting forest inventories in the mid to late 1990s. Thus early LiDAR theory and applications were developed for commercial forests typical of a region with gentle topography; conditions far different from those of the temperate rain forests of the Pacific Northwest. To develop LiDAR data acquisition specifications and...

Douglas-fir (Pseudotsuga menziesii), one of the most economically and ecologically important tree species in the world, also has one of the largest tree breeding programs. Although the coastal and interior varieties of Douglas-fir (vars. menziesii and glauco) are native to North America, the coastal variety is also widely planted for timber production in Europe, New Zealand, Australia, and Chile. Our main goal was to develop a SNP resource large enough to facilitate genomic selection in Douglas-fir breeding programs. To accomplish this, we developed a 454-based reference transcriptome for...

Fire behavior modeling and geospatial analyses can provide tremendous insight for land managers as they grapple with the complex problems frequently encountered in wildfire risk assessments and fire and fuels management planning. Fuel management often is a particularly complicated process in which the benefits and potential impacts of fuel treatments need to be demonstrated in the context of land management goals and public expectations. The fuel treatment planning process is complicated by the lack of data assimilation among fire behavior models and weak linkages to geographic information...

Introduced plant species have significant negative impacts in many ecosystems and are found in many forests around the world. Some factors linked to the distribution of introduced species include fragmentation and disturbance, native species richness, and climatic and physical conditions of the landscape. However, there are few data sources that enable the assessment of introduced species occupancy in native plant communities over broad regions. Vegetation data from 1302 forest inventory plots across 24 states in the northeastern and mid-western United States were used to examine and...

Federal policies in the US strongly emphasize reducing hazardous fuels at the Wildland Urban Interface (WUI). However, these areas present restoration challenges as they often have exotic weeds, frequent human disturbance, and the presence of roads. Understanding seed banks is important in planning for desirable post-disturbance community conditions, developing integrated weed management programs, and complying with State and Federal regulations. We characterized the aboveground vegetation and seed bank in a WUI composed of mixed age dry-mixed conifer forest stands in central Washington...

Changes in human land use patterns have wide-ranging social, economic and ecological implications. How urban and residential areas develop to accommodate population increase can have varying effects on forest and agricultural production from resource lands. Estimates of the amount and type of land use change differ substantially with definitions and analytical methods used. The purpose of this study was to apply a robust manual image classification method to assess changes in land use and housing density across Washington state for a 30-year period. Digital imagery from 1976, 1994, and...

We sampled trees grown with and without competing vegetation control in an 11-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) plantation on a highly productive site in southwestern Washington to create diameter based allometric equations for estimating individual-tree bole, branch, foliar, and total aboveground biomass. We used these equations to estimate per-hectare aboveground biomass, nitrogen (N), and carbon (C) content, and compared these results to (1) estimates based on biomass equations published in other studies, and (2) estimates made using the mean-tree...