Treesearch

Since 2004, the Valles Caldera National Preserve (VCNP) in the Jemez Mountains of northern New Mexico has hosted extensive field hydrology research by scientists from the Center for Sustainability of semi- Arid Hydrology and Riparian Areas (SAHRA) at the University of Arizona. With the development of a detailed hydrologic understanding of VCNP's climate, geology, soils, vegetation, and hydrology, preserve managers have begun to incorporate research results into their management planning for rangelands, forests, and watersheds, including specific programs such as livestock grazing and...

Sharpleaf penstemon is primarily used as a forb component for wildlife habitat enhancement and restoration efforts. Its showy flowers attract numerous pollinators and other insects that provide a food source for birds and other vertebrates. This species is used in xeriscaping and other low-wateruse landscaping. It is suited for roadside and other beautification plantings.

Like many species of amphibians, Boreal Toads (Bufo boreas boreas, Bufonidae) are declining throughout portions of their range. Recent efforts have focused on describing the ecology of this species, yet few studies have evaluated demographic characteristics that may influence the persistence of Boreal Toad populations. Because Boreal Toads often convey themselves down valleys via stream channels in some areas, we set upstream-facing hoop nets in early to late summer in several first- to third-order tributaries in two western Montana river basins to assess the sizes of individuals using...

Diameter growth (DG) equations in many existing forest growth and yield models use tree crown ratio (CR) as a predictor variable. Where CR is not measured, it is estimated from other measured variables. We evaluated CR estimation accuracy for the models in two Forest Vegetation Simulator variants: the exponential and the logistic CR models used in the North Idaho (NI) variant, and the Weibull model used in the South Central Oregon and Northeast California (SO) variant. We also assessed the effects of using measured (CRm) versus predicted (CRp) crown ratio for predicting 10 year DG and 30...

Coleogyne ramosissima Torr. (blackbrush) and Atriplex confertifolia [Torr. & Frem.] Wats. (shadscale) are cold desert shrubs from different families. Despite very different life histories they often grow in close geographic proximity in the Great Basin and the Colorado Plateau between 800 and 2000 m elevation. The purpose of this study is to compare the ecophysiology of slow growing and reproducing blackbrush with the ecophysiology of faster growing and reproducing shadscale. Metabolic heat and carbon dioxide production rates were measured on leaf tissue from wild plants and on lab-grown...

Concerns about the long-term sustainability of overstocked dry conifer forests in western North America have provided impetus for treatments designed to enhance their productivity and native biodiversity. Dense forests are increasingly prone to large stand-replacing fires; yet, thinning and burning treatments, especially combined with other disturbances such as drought and grazing, may enhance populations of colonizing species, including a number of non-native species. Our study quantifies plant standing crop of major herbaceous species across contrasting stand structural types representing...

We conduct long-term amphibian monitoring in Yellowstone National Park (YNP) (1) and read McMenamin et al.'s article (2) with interest. This study documents decline in the extent of seasonal wetlands in the Lamar Valley of YNP during extended drought, but the conclusion, widely reported in the media, of "severe declines in 4 once-common amphibian species," is unsupported. This study wrongly defines sites occupied by one nonbreeding individual as "populations

While the main objective of many silvicultural treatments in the western US is to reduce fire potential, their effects on overstory regeneration, midstory and herbaceous communities is of importance to land managers. To quantify these effects, we measured overstory regeneration, midstory density by species, herbaceous biomass, species richness and cover in commercial and non-commercial treatments with differing slash prescriptions in dry mixed conifer stands of south central New Mexico. Results indicated that overstory regeneration and shrub density were not significantly affected by...

The Anaxyrus boreas species group currently comprises four species in western North America including the broadly distributed A. boreas, and three localized species, Anaxyrus nelsoni, Anaxyrus exsul and Anaxyrus canorus. Phylogenetic analyses of the mtDNA 12S rDNA, cytochrome oxidase I, control region, and restriction sites data, identified three major haplotype clades. The Northwest clade (NW) includes both subspecies of A. boreas and divergent minor clades in the middle Rocky Mountains, coastal, and central regions of the west and Pacific Northwest. The Southwest (SW) clade includes A....

Root hydrogel, a hydrophilic polymer, has been used to improve transplanting success of bareroot conifer seedlings through effects on water holding capacity. We examined mechanisms by which Terra-sorb Fine Hydrogel reduces damage that occurs when roots of 1-year old, dormant northern red oak (Quercus rubra L.) were subjected to shortterm (1, 3, and 5 h) pre-transplanting desiccation and long-term (45 days) drought stress following transplanting in a controlled environment chamber or greenhouse conditions. Hydrogel-treated seedlings had 80% greater root moisture content than non-root dipped...