Treesearch

When addressing the nature of ecological adaptation and environmental factors limiting population ranges and contributing to speciation, it is important to consider not only the plant's genotype and its response to the environment, but also any close interactions that it has with other organisms, specifically, symbiotic microorganisms. To investigate this, soils and seedlings were reciprocally transplanted into common gardens of the big sagebrush hybrid zone in Salt Creek Canyon, Utah, to determine location and edaphic effects on the fitness of parental and hybrid plants. Endophytic...

1. Flooding governs riparian plant diversity along boreal rivers but the ecological role of extreme floods is only partly understood. We studied the dynamics of riparian plant composition and richness in the free-flowing Vindel River in northern Sweden, and the importance of reach type in sustaining high species richness. 2. We conducted three surveys of riparian plant species richness over a period of two decades. The first and last of these surveys were conducted 1-3 years after significant flooding and the second was carried out after a period of more moderate flooding. 3. Our results...

Accelerated runoff and erosion commonly occur following forest fires due to combustion of protective forest floor material, which results in bare soil being exposed to overland flow and raindrop impact, as well as water repellent soil conditions. After the 2000 Valley Complex Fires in the Bitterroot National Forest of west-central Montana, four sets of six hillslope plots were established to measure first-year post-wildfire erosion rates on steep slopes (greater than 50%) that had burned with high severity. Silt fences were installed at the base of each plot to trap eroded sediment from a...

Landscape genetics has emerged as a new research area that integrates population genetics, landscape ecology and spatial statistics. Researchers in this field can combine the high resolution of genetic markers with spatial data and a variety of statistical methods to evaluate the role that landscape variables play in shaping genetic diversity and population structure. While interest in this research area is growing rapidly, our ability to fully utilize landscape data, test explicit hypotheses and truly integrate these diverse disciplines has lagged behind. Part of the current challenge in...

In the western United States, Euro-American settlement was concentrated on the most fertile, best-watered, and most desirable sites, while the unsettled mountains and deserts remained in the public domain. As a result, the public and private halves of the western landscape are not interchangeable for conservation purposes. Federal statutes require ranchers grazing livestock on federal lands to own sufficient private ranchland, known as “base ranch” or “commensurate” land, to sustain their livestock for part of each year. If access to forage on public lands is curtailed, the economic...

Habitat connectivity and corridors are often assumed to be critical for the persistence of patchily distributed populations, but empirical evidence for this assumption is scarce. We assessed the importance of connectivity among habitat patches for dispersal by a mature-forest obligate, the Boreal Owl (Aegolius funereus). Boreal Owls demonstrated a lack of genetic structure (θ = 0.004 ± 0.002 [SE]) among subpopulations, regardless of matrix type and extent, which indicates that unforested matrix does not act as a barrier to dispersal for this vagile species. We found only slightly higher...

When Hubert Humphrey first introduced the Wilderness Act to the U.S. Senate in 1956, he said that “the agency having jurisdiction over any area within this [Wilderness] System will have the sanction and encouragement of Congress and the legal responsibility for preserving the area’s wilderness character.” Now, five decades later, the U.S. Forest Service developed a protocol to monitor trends in wilderness character. This protocol, as explained in IJW articles published in December 2004 and December 2006, assesses whether the wilderness character of a wilderness area is improving, stable,...

Human communities in the Intermountain West depend heavily on subalpine rangelands because of their importance in providing water for irrigation and forage for wildlife and livestock. In addition, many constituencies are looking to managed ecosystems to sequester carbon in plant biomass and soil C to reduce the impact of anthropogenic CO2 on climate. This work builds on a 90-year-old grazing experiment in mountain meadows on the Wasatch Plateau in central Utah. The purpose of this study was to evaluate the influence of 90 years of protection from grazing on processes controlling the input,...

Management of young forests is not often considered in conservation plans, but young forests provide habitat for some species of conservation concern. Snowshoe hares (Lepus americanus), critical prey of forest carnivores including the United States federally threatened Canada lynx (Lynx canadensis), can be abundant in young montane and subalpine forests with densely spaced saplings and shrub cover. Precommercial thinning (PCT) is a silvicultural technique that reduces sapling and shrub density on young forest stands. We tested for effects of PCT on snowshoe hare abundance for 2 years after...

This study describes local personal and community relationships with the Bitterroot National Forest, Montana. Using a rapid appraisal research approach, a range of personal and community values was identified. Participants were asked to identify places they valued on the forest and why they valued them. Study results indicate that local relationships exist on several scales. First, people differentiate the set of values they ascribe to places they have visited from those places they have not. Two sets of values, at two very different scales, emerged in their descriptions of places they...