Treesearch

President Lyndon Baines Johnson signed the Wilderness Act into law on Sept. 3, 1964. In this photo, LBJ hands the pen he used to Alice Zahniser while naturalist, author, adventurer, and conservationist Mardy Murie (standing behind her) looks on.

The National Wilderness Preservation System (NWPS) is a vital component of the national and international infrastructure for science, education, and information. The NWPS serves as an important resource for advancing research, from discovering new dinosaurs (Arbour et al. 2014, Landon 2016) to understanding human history on the American landscape (Rasic 2003). The NWPS provides invaluable records of environmental change and coverage of important types of ecosystems and natural resource systems (Aycrigg et al. 2016).

We explore the connection between US designated wilderness areas and wildlife with the goal of establishing a research agenda for better understanding this complex relationship. Our research agenda has two components. The first, "wildlife for wilderness," considers the impact of wildlife on wilderness character. Whereas studies show that wildlife is important in both the perception and actual enhancement of wilderness character, the context and particulars of this relationship have not been evaluated. For instance, is knowing that a rare, native species is present in a wilderness area...

Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings from three nurseries in the Pacific Northwest United States were lifted on five dates from mid-October through mid-December 2006. Each nursery provided seedlings from a low- and a high-elevation seed lot. Photoperiod and accumulated chilling hours (calculated using two methods) were evaluated throughout the lifting period. Seedlings had typical patterns of fall cold hardiness development, with some indication that the high-elevation lot at each nursery was hardier than the low-elevation lot. Photosynthetic yield measured on...

Recent concern regarding the potential decline of quaking aspen (Populus tremuloides Michx.) forests in the western United States has sparked concern over whether the species can be effectively regenerated. Using a retrospective approach, we quantified the response of regenerating aspen stems to an ordinary set of silvicultural treatments conducted over approximately the past decade in southern Utah, USA. A suite of variables describing stand structure and composition, stand vigor, physiographic factors, herbivore pressure, and treatment types were measured to predict the possible controls,...

Higher global temperatures are changing ecosystems in the Arctic. They are becoming greener as the climate and land become more hospitable to taller vegetation. Scientists predict that woody vegetation in the Arctic will increase by more than 50 percent, and half of all vegetated areas will shift to types more suited to the higher temperatures and changing physical conditions. The implications for wildlife and people living in the Arctic are striking and hinge on rapid changes affecting ecosystems and habitats.Bruce Marcot, a research wildlife biologist with the Pacific Northwest Research...

A conservation goal of the Northwest Forest Plan (NWFP) is to stabilize and increase marbled murrelet (Brachyramphus marmoratus) populations by maintaining and increasing nesting habitat. We monitored murrelet populations offshore of the NWFP area from 2000 to 2013 to estimate population size and trend at several spatial scales. At the conservationzone scale, 2013 population estimates ranged from 71 birds in Conservation Zone 5 (San Francisco Bay north to Shelter Cove, California) to 7,880 in Conservation Zone 3 (Coos Bay, Oregon north to the Columbia River). The 2013 estimate for the...

Climate predictions for the Mediterranean Basin include increased temperatures, decreased precipitation, and increased frequency of extreme climatic events (ECE). These conditions are associated with decreased tree growth and increased vulnerability to pests and diseases. The anatomy of tree rings responds to these environmental conditions. Quantitatively, the width of a tree ring is largely determined by the rate and duration of cell division by the vascular cambium. In the Mediterranean climate, this division may occur throughout almost the entire year. Alternatively, cell division may...

Invasive earthworms perturb natural forest ecosystems that initially developed without them, mainly by consuming the forest floor (an organic rich surficial soil horizon) and by mixing the upper parts of the soil. The fate of mercury (Hg) formerly contained in the forest floor is largely unknown. We used two mass balance approaches (simple mass balance and geochemical mass balance) to quantitatively assess the impact of exotic earthworms on Hg cycling in forest soils and the fate of Hg formerly contained in the forest floor. Two sets of soils, collected in 2009 and 2014 from an earthworm...

There are an estimated 10.7 million family forest ownerships across the United States who collectively control 36% or 290 million acres of the nation's forestland. The US Department of Agriculture Forest Service National Woodland Owner Survey (NWOS) provides information on the characteristics, attitudes, and behaviors of these ownerships. Between 2011 and 2013, 8,576 randomly selected family forest ownerships with at least 10 acres of forestland participated in the NWOS. Results show: amenity values are the dominant reasons for owning; owners tend to be active on their land, but most are...