Treesearch

City dwellers can find many reasons to value neighborhood trees. The urban greenery provides relief from the built environment that many find appealing. In fact, a previous study found that a tree in front of a home increased that home's sales price by more than $7,000. Two new studies explore the measurable effects that urban trees and green spaces have a human health and crime rates. Geoffrey Donovan, a research forester with the Pacific Northwest Research Station, used public health data, crime statistics, tax records aerial photos and other information in the two studies. He found that...

The 1994 Northwest Forest Plan (NWFP) established a common management approach across federal land within the range of the northern spotted owl. It also established a monitoring framework to track, among other things, the plan’s effectiveness at maintaining and restoring late-successional and old-growth forests. Station scientists Janet Ohmann and Warren Cohen contributed to the recently published 15-year report by the Interagency Regional Monitoring Team on the status and trends of these older forests the Pacific Northwest. Ohmann, Cohen, and their colleagues used a novel mapping approach...

The Forest Inventory and Analysis program collected, analyzed, and summarized field data on 44 forested field plots for the 10 largest atoll groups in the Republic of the Marshall Islands (RMI): Ailinglaplap, Arno, Jaluit, Kwajalein, Likiep, Majuro, Maloelap, Mili, Rongelap, and Wotje. Estimates of forest area, tree stem volume and biomass, the numbers of trees, tree damages, and the distribution of tree sizes were summarized for this statistical sample. A variety of tables with graphical highlights provide a summary of RMI’s forest resources and a comparison to prior vegetation mapping...

This guidebook describes Camas Swale Research Natural Area, a 127-ha (314-ac) area that supports dry site, old-growth Douglas-fir (Pseudotsuga menziesii) forest. Major plant associations present within the area include the Douglas-fir/salal/western swordfern (Pseudotsuga menziesii/Gaultheria shallon/Polystichummunitum) plant association, Douglas-fir/Oregongrape (Pseudotsuga menziesii/Berberis nervosa) plant association, Douglas-fir/poison oak (Pseudotsuga menziesii/Toxicodendron diversilobum) plant association, and Douglas-fir/hazelnut-trailing snowberry/western swordfern (Pseudotsuga...

This guidebook describes Cherry Creek Research Natural Area, a 239-ha (590-ac) area that supports old-growth Douglas-fir-western hemlock (Pseudotsuga menziesii- Tsuga heterophylla) forest occurring on sedimentary materials in the southern Oregon Coast Range. Major plant associations present within the area include the western hemlock/Oregon oxalis (Oxalis oregana) plant association, the western hemlock/evergreen huckleberry (Vaccinium ovatum) plant association, and the western hemlock/rhododendron-Oregon grape (Rhododendron macrophyllum- Berberis nervosa) plant association. A northern...

The objective of this paper was to evaluate the potential for fully physical fire models to simulate the interactions between two converging fire fronts (a head fire and a back fire), in conditions similar to those encountered during suppression fireoperations. The simulations were carried out using two fully physical models: FIRESTAR, in two dimensions, and Wildland Fire Dynamics Simulator, in three dimensions. Each modelling approach numerically solves a set of balance equations (mass, momentum, energy, etc.) governing the behaviour of the coupled systemformed by the vegetation and the...

Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool for estimating the biomass resources available to support bioenergy production in rural communities of interior Alaska. In this study, we present a methodology for estimating forest biomass over a 201,226-ha area (of which 163,913 ha are forested) in the upper Tanana valley of interior Alaska using a combination of 79 field plots and high-density airborne light detection and ranging (LiDAR) collected in a sampling mode along 27 single strips (swaths) spaced approximately 2.5 km apart. A model-base...

Where belowground resources are relatively abundant, naturally established trees sometimes occur in very close proximity to one another. We conducted a two-year study to assess the aboveground interactions between Douglas-fir (Pseudotsuga menziesii), grand fir (Abies grandis) and noble fir (Abies procera) seedlings planted in closely spaced (stems 10 cm apart) conspecific and heterospecific pairs. Paired seedling growth also was compared to seedlings planted with no neighbor. Stem height growth was not affected by the presence of a neighbor seedling, although diameter growth was slightly...

We assessed the effect of harvest type (bole-only or whole-tree) and vegetation control treatments (initial or annual application of herbicide) on soil C and N at two contrasting sites in the Pacific Northwest. Pretreatment (2003) and posttreatment (2005) soil samples were collected by depth to 60 cm, and a stratified sampling approach based on four surface conditions was used for posttreatment sampling in surface soils. Surface condition had a significant effect on soil C and N concentrations, generally decreasing with decreasing amounts of logging debris and increasing soil disturbance....

The 2002 Biscuit Fire burned at mixed-severities encompassing over 200,000 ha of publicly owned forestland, including more than 8300 ha of conifer plantations. We used pre- and post-fire digital aerial photography to examine how the level of canopy damage varied within these plantations in relation to topography, weather, vegetation-cover, and management history, with an emphasis on the age of the plantation. We examined 198 plantations that varied widely in age (5–47 years), size (1.25–47 ha), and landscape context. The average level of canopy damage within the plantations was 77%. Based...