Treesearch

Lichens are an important winter forage for large, migratory herds of caribou (Rangifer tarandus granti) that can influence population dynamics through effects on body condition and in turn calf recruitment and survival. We investigated the vegetative and physiographic characteristics of winter range of the Western Arctic Herd in northwest Alaska, one of the largest caribou herds in North America. We made three broad comparisons: habitats used by caribou versus random locations, burned versus unburned habitats, and habitats within the current winter range versus those in the historic winter...

Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (DFB) causes considerable mortality to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in western North American forests. We evaluated the use of semiochemical-baited multiple-funnel traps for the protection of small, high-value stands of trees, such as those occurring in campgrounds, rest areas, and small parks when Douglas-fir mortality caused by populations of DFB were at levels of concern to land managers. At two sites in western Montana in 2004, three treated plots were surrounded by three trapping stations arranged in an...

Resilience thinking addresses the dynamics and development of complex social-ecological systems (SES). Three aspects are central: resilience, adaptability and transformability. These aspects interrelate across multiple scales. Resilience in this context is the capacity of a SES to continually change and adapt yet remain within critical thresholds. Adaptability is part of resilience. It represents the capacity to adjust responses to changing external drivers and internal processes and thereby allow for development along the current trajectory (stability domain). Transformability is the...

It was in June, 1966 when I started working for the tree disease scientists at the Forestry Sciences Laboratory in Moscow, Idaho. That autumn I would start my University course in Forestry which eventually would lead to a long and rewarding career as a Forest Pathologist. But I knew none of that 44 years ago as a lowly paid summer aid hired by the Blister Rust research project. We were evaluating the effects of antibiotics (Actidione and Phytoactin) on established blister rust cankers on western white pine. My job was to locate the previously marked study trees (often not as simple as it...

The increase in collaborative projects involving American Indian tribes and natural resource management agencies in the United States reflects two emergent trends: 1) the use of collaborative approaches between agencies and groups in managing natural resources; and 2) the concurrent increased recognition of American Indian rights, institutionalization of consultation processes, and a general movement of Indian self-determination. This article focuses on institutional mechanisms that bring together tribes and natural resource management agencies in collaborative processes to achieve...

The socioeconomic and environmental features of local places (community context) influence the relationship between humans and their physical environment. In times of environmental disturbance, this community context is expected to influence human perceptual and behavioral responses. Residents from nine Colorado communities experiencing a large outbreak of mountain pine beetles (Dendroctonus ponderosae) were surveyed in 2007. Multiple analytic methods including ordinary least squares regression and multilevel modeling techniques were used to evaluate a community-context conceptual model of...

While the impacts of long-term climate change trends on glacier hydrology have received much attention, little has been done to quantify direct glacier runoff contributions to streamflow. This paper presents an approach for determining glacier runoff contributions to streamflow and estimating the effects of increased temperature and decreased glacier area on future runoff. We focus on late summer streamflow (when flow is lowest and nonglacier contributions to flow are minimal) of a small glacierized watershed on the flanks of Mount Hood, Oregon, United States. Field and lab measurements...

Boreal forests are an important source of wood products, and fertilizers could be used to improve forest yields, especially in nutrient poor regions of the boreal zone. With climate change, fire frequencies may increase, resulting in a larger fraction of the boreal landscape present in early successional stages. Since most fertilization studies have focused on mature boreal forests, the response of burned boreal ecosystems to increased nutrient availability is unclear. Therefore, we used a nitrogen (N) fertilization experiment to test how carbon (C) cycling in a recently-burned boreal...

Ecosystem models have not comprehensively considered how interactions among fire disturbance, soil environmental conditions, and biogeochemical processes affect ecosystem dynamics in boreal forest ecosystems. In this study, we implemented a dynamic organic soil structure in the Terrestrial Ecosystem Model (DOS-TEM) to investigate the effects of fire on soil temperature, moisture, and ecosystem carbon dynamics. DOS-TEM consists of environmental, ecological, disturbance effects, and dynamic organic soil modules. Changes in organic layer thickness are computed from calculated changes in...

Changes in Earth's environment are expected to stimulate changes in the composition and structure of ecosystems, but it is still unclear how the dynamics of these responses will play out over time. In long-lived forest systems, communities of established individuals may be resistant to respond to directional climate change, but may be highly sensitive to climate effects during the early life stages that follow disturbance. This study combined analyses of pre-fire and post-fire tree composition, environmental data, and tree ring analyses to examine landscape patterns of forest recovery...