Treesearch

Initiated simultaneously, the Density Management and Riparian Buff er Study of western Oregon and the Northwest Forest Plan have had intertwining paths related to federal forest management and policy changes in the Pacifi c Northwest over the last 15 to 20 years. We briefl y discuss the development of the Northwest Forest Plan and how it changed the way forest policy was developed in the region. Th e concurrent conceptualization and implementation of the Density Management and Riparian Buff er Study within this new management framework resulted in a proof-of-concept for adaptive management...

Th inning has been promoted as a method for accelerating the development of late-seral habitat and improving the overall health and function of young forests in the Pacifi c Northwest. Population studies have shown early and positive responses to thinning by some small forest-floor mammals (primarily mice, terrestrial voles, and shrews). However, thinning reduces the abundance of some tree-dwelling rodents, especially Northern Flying Squirrels (Glaucomys sabrinus) and Red Tree Voles (Arborimus longicaudus), that are important prey species for Northern Spotted Owls (Strix occidentalis...

Recent bark beetle outbreaks have had a significant impact on forests throughout western North America and have generated concerns about interactions and feedbacks between beetle attacks and fire. However, research has been hindered by a lack of experimental studies and the use of fire behavior models incapable of accounting for the heterogeneous fuel complexes. We populated the Wildland-Urban Interface Fire Dynamics Simulator with data from 11 field sites to investigate the effect of mountain pine beetle (MPB)-caused tree mortality on simulated crown fire behavior across a range of...

The cultivated strawberry is one of the youngest domesticated plants, developed in France in the 1700s from chance hybridization between two western hemisphere octoploid species. However, little is known about the evolution of the species that gave rise to this important fruit crop. Phylogenetic analysis of chloroplast genome sequences of 21 Fragaria species and subspecies resolves the western North American diploid F. vesca subsp. bracteata as sister to the clade of octoploid/decaploid species. No extant tetraploids or hexaploids are directly involved in the maternal ancestry of the...

Adoption of the Northwest Forest Plan (NWFP, USDA and USDI 1993, 1994) in the early 1990s signaled a major shift in forest management on federal lands in western Oregon and Washington. The Plan refl ected composite concerns raised by various resource managers, conservation groups, scientists, and the general public about the sustainability of production-oriented forestry as practiced from the early 1900s. Specifi cally, the plan addressed concerns regarding clearcutting, the harvest of old-growth trees and loss of related habitat, and threats to more than 1,000 potentially sensitive...

We present preliminary results from an experiment in which alternative forest buff er treatments were applied to clusters of watersheds in southwest Washington using a Before-After-Control-Impact (BACI) design. Th e treatments occurred on small (~2- to 9-ha) headwater catchments, and compared continuous fi xed-width buff ered, discontinuous patch-buff ered, and unbuffered streams to an adjacent unlogged reference catchment. Eight treatment clusters were monitored from 2001 to 2006; four were located in the Black Hills (Capitol State Forest) and four in the Willapa Hills of the Coast Range....

Concerns about climate change have generated worldwide interest in managing forests for the uptake and storage of carbon (C). Simultaneously, preserving and enhancing structural, functional, and species diversity in forests remains an important objective. Therefore, understanding tradeoffs and synergies among C storage and sequestration and diversity in managed forests is key to achieving these multiple objectives. Using the experimental framework of the Density Management Study in western Oregon, we examined the relationships among a suite of thinning treatments, above-ground carbon...

Headwater systems, including the channel and the adjacent riparian forest, are a dominant landscape feature in forested watersheds, draining most of the watershed area, and comprising the majority of channel length in drainage networks. Being at the upper extent of watersheds, these systems are smaller and steeper than large streams, and create microhabitats that support diverse instream communities distinct from those in larger streams. Forest management can disturb headwater streams through changes in physical structure, sediment, light, and riparian detrital inputs. Locally, the extent...

Riparian areas are extremely variable and dynamic, and represent some of the most complex terrestrial ecosystems in the world. The high variability within and among riparian areas poses challenges in developing efficient sampling and modeling approaches that accurately quantify riparian forest structure and riparian microclimate. Data from eight stream reaches that are part of the Density Management Study were used in a variety of recent studies that explored sampling and modeling approaches for riparian forest structure and microclimate, and the results are summarized here. When sixteen...

Because forest ecosystems have the capacity to store large quantities of carbon (C), there is interest in managing forests to mitigate elevated CO2 concentrations and associated effects on the global climate. However, some mitigation techniques may contrast with management strategies for other goals, such as maintaining and restoring biodiversity. Forest thinning reduces C storage in the overstory and recruitment of detrital C. These C stores can affect environmental conditions and resource availability in the understory, driving patterns in the distribution of early and late-seral...