Treesearch

Forest birds are sensitive to habitat change and may be suitable for measuring responses to retention forestry. I present the short-term effects of 6 treatments in a 6 block randomized design experiment on 15 breeding small bird species in mature Douglas-fir (Pseudotsuga menziesii) forests in western Washington and Oregon, 1994–2001. The 13-ha treatment stands contained aggregated (A) green-tree retentions of 100, 75, 40 and 15%, and a dispersed tree distribution pattern (D) of 40 and 15% retention. I compared numbers of entire singing bird territories (abundances) mapped inside sampling...

Tropospheric ozone (O3) is an important stressor in natural ecosystems, with well documented impacts on soils, biota and ecological processes. The effects of O3 on individual plants and processes scale up through the ecosystem through effects on carbon, nutrient and hydrologic dynamics. Ozone effects on individual species and their associated microflora and fauna cascade through the ecosystem to the landscape level. Systematic injury surveys demonstrate that foliar injury occurs on sensitive species throughout the globe. However, deleterious impacts on plant carbon, water and nutrient...

• Origins of abscisic acid (ABA)-mediated metabolic control of stomatal conductance have been suggested to be recent, based on a gradualistic model of stomatal evolution. In ferns, steady-state stomatal conductance (gs) was unresponsive to ABA in some studies, supporting this model. Stomatal kinetic responses to ABA have not been considered. • We used dynamic gas exchange methods to characterise half times of stomatal opening and closing in response to step changes in light, across a range of ABA exposures in three diverse taxa. • All taxa had asymmetric kinetics, with closure slower than...

Changes to the fire regime in boreal Alaska are shifting the ratio of coniferous to deciduous dominance on the landscape. The increase in aspen and birch may have important effects on predatory hymenopteran assemblages by providing a source of extrafloral nectar and increasing prey availability. Furthermore, fire-induced changes in successional age alter habitat structure and microclimate in ways that may favor ants. This study is the first to characterize the influence of fire-related vegetation changes on boreal predatory hymenopteran assemblages. We compare the abundance, species...

Bayesian network (BN) modeling is a rapidly advancing field. Here we explore new methods by which BN model development and application are being joined with other tools and model frameworks. Advances include improving areas of Bayesian classifiers and machine-learning algorithms for model structuring and parameterization, and development of time-dynamic models. Increasingly, BN models are being integrated with: management decision networks; structural equation modeling of causal networks; Bayesian neural networks; combined discrete and continuous variables; object-oriented and agent-based...

Slow ecological processes challenge conservation. Short-term variability can obscure the importance of slower processes that may ultimately determine the state of a system. Furthermore, management actions with slow responses can be hard to justify. One response to slow processes is to explicitly concentrate analysis on state dynamics. Here, we focus on identifying drivers of Northern Spotted Owl (Strix occidentalis caurina) territorial occupancy dynamics across 11 study areas spanning their geographic range and forecasting response to potential management actions. Competition with Barred...

We examined traditional knowledge of fire use by the Ichishikin (Sahaptin), Kitsht Wasco (Wasco), and Numu (Northern Paiute) peoples (now Confederated Tribes of Warm Springs, CTWS) in the eastside Cascades of Oregon to generate insights for restoring conifer forest landscapes and enhancing culturally-valued resources. We examined qualitative and geospatial data derived from oral history interviews, participatory GIS focus groups, archival records, and historical forest surveys to characterize cultural fire regimes (CFRs) –an element of historical fire regimes– of moist mixed conifer (MMC),...

Recreating on public land is increasingly popular in the Pacific Northwest. Recreation management requires balancing opportunities for people to enjoy the outdoors with mitigating the effects on wildlife and other natural resources. Recreation and wildlife managers grappling with these issues asked Forest Service scientists to quantify the impacts of motorized and nonmotorized recreation on elk. Elk are highly valued for hunting and viewing by the public, and as large herbivores, they play a critical role in many ecosystems of the Intermountain West.A large fenced area within the Starkey...

Biodiversity conservation in mixed-ownership landscapes often depends on contributions from privatelyowned lands, where natural resource development can alter and produce novel habitat conditions for species of conservation concern. A lack of research on private lands stemming from access issues and concerns over regulatory outcomes, however, often limits evaluation of the impact of land management. The California spotted owl (Strix occidentalis occidentalis), for example, often occurs in mixed-ownership landscapes but research on this species has occurred primarily on public lands....

The Mount St. Helens eruption on May 18, 1980, fundamentally transformed the surrounding landscape. The eruption triggered geophysical processes that are still unfolding. A debris avalanche caused by the eruption, for example, blocked the outlet from Spirit Lake. To prevent the rising lake level from breaching the blockage and potentially flooding communities downstream, the U.S. Army Corps of Engineers built an outlet tunnel to maintain safe lake levels. However, the tunnel must be periodically closed for repairs, during which time the lake can rise precariously high.In 2015, the Gifford...