Treesearch

Many public land management agencies are committed to understanding and protecting recreation visitor experiences. Parks Canada is deeply committed to that objective for visitors to Canada's National Parks. This 2004 study, informed by a 2003 qualitative study of visitor experiences and influences on those experiences at Auyuittuq National Park in Nunavut, worked to bring 50 potential elements of visitor experiences down to five articulated dimensions of the experience that is currently being received at this remote eastern arctic park. A hypothesized set of 17 influences on experiences,...

Barriers to effective communication between researchers and managers can ultimately result in barriers to the application of scientific knowledge and technology for land management. Both individual and organizational barriers are important in terms of how they affect the first three stages of the innovation-decision process: 1) knowledge, where an individual is exposed to innovation and develops an understanding of how it works; 2) evaluation, where an individual evaluates advantages and disadvantages and forms a favorable or unfavorable attitude toward innovation; and 3) decision, where...

Many resource managers and wilderness advocates see links between appreciating wild nature, participating in traditional outdoor activities, and support for protecting wild areas. Some of these individuals express concern that the values and recreation behavior of today's young people may suggest less support for protecting wilderness in the future. Although emerging adults appear to express strong pro-environmental values, they exhibit outdoor recreation patterns strikingly different from the past. More questions than answers exist about emerging adults' environmental and wilderness...

Carbon allocation plays a critical role in forest ecosystem carbon cycling. We reviewed existing literature and compiled annual carbon budgets for forest ecosystems to test a series of hypotheses addressing the patterns, plasticity, and limits of three components of allocation: biomass, the amount of material present; flux, the flow of carbon to a component per unit time; and partitioning, the fraction of gross primary productivity (GPP) used by a component. Can annual carbon flux and partitioning be inferred from biomass? Our survey revealed that biomass was poorly related to carbon flux...

Soil nutrient availability influences plant invasions. Resin capsules were used to examine soil nutrient bioavailability along 2 sagebrush-grassland elevation transects in the east Tintic Range (Utah) and Shoshone Range (Nevada). In the fall of 2001, treatments were applied to 3 replicate plots at each site, which included prescribed burning, herbaceous vegetation removal, and controls. Cheatgrass (Bromus tectorum L.) was overseeded in small subplots within each treatment. Following treatments in each plot, resin capsules were installed at 15-cm depth in a shrub interspace and a B....

Pinyon and juniper have been expanding into sagebrush (Artemisia tridentata) ecosystems since settlement of the Great Basin around 1860. Herbaceous understory vegetation is eliminated as stand densities increase and the potential for catastrophic fires increases. Prescribed fire is increasingly used to remove trees and promote recovery of sagebrush ecosystems.

Invasion and dominance of weedy species is facilitated or constrained by environmental and ecological factors that affect resource availability during critical life stages. We compared the relative effects of season, annual weather, site, and disturbance on potential cheatgrass (Bromus tectorum L.) germination in big sagebrush (Artemisia tridentata Nutt.) communities. Soil water status and temperature in the seedbed were measured continuously for 4 years on 9 big sagebrush sites in Nevada and Utah. Field plots at lower-, middle-, and upper-elevation sites were either undisturbed, or were...

Sediment transport rates (dissolved, suspended, and bedload) measured over the course of several years are reported for two streams in the Gros Ventre Mountain range in western Wyoming, USA: Little Granite and Cache Creeks. Both streams drain watersheds that are in relatively pristine environments. The sites are about 20km apart, have runoff dominated by snowmelt and are underlain by a similar geological setting, suggesting that sediment supply and rates of transport in the two watersheds may be comparable. Yet, estimated sediment yields for the two sites appear substantially different. On...

We present a linear model for the interacting effects of elevation, aspect, and slope for use in predicting forest productivity or species composition. The model formulation we propose integrates interactions of these three factors in a mathematical expression representing their combined effect in terms of a cosine function of aspect with a phase shift and amplitude that change with slope and elevation. This model allows the data to determine how the aspect effect changes with elevation and slope. Earlier articles concerning the interactions of slope, aspect, and elevation have been...

The Rio Grande has been identified as one of the most endangered rivers in the United States by American Rivers. Water impoundment, water extraction, and point-source pollution have likely contributed to the decline of the federally endangered Rio Grande silvery minnow (Hybognathus amarus). The overall goal of this study was to locate, identify, and characterize food resources for H. amarus and the ichthyofauna of the Middle Rio Grande (MRG). After locating possible food resources (chapter 1) A single diatom cell was isolated from a mixed environmental collection and grown in monoculture....