Treesearch

Management of rangelands has changed substantially over the past few decades; today there is greater emphasis on wildlife management and increased interest in using natural disturbances such as fire to manage rangeland plant and animal communities. To determine the effect of prescribed fires on the distribution of white-tailed deer (Odocoileus virginianus), we used Global Positioning System (GPS) collars to monitor the movements of bucks and does during four, month-long, trials before and during the year after implementation of three late summer burns. Deer were expected to increase their...

In order to optimize production, range managers need to understand and manage the spatial distribution of free-ranging herbivores, although this task becomes increasingly difficult as ranching operations diversify to include management of wildlife for recreational hunting. White-tailed deer are sympatric with cattle throughout much of their range and are a valuable commodity in southern rangelands. The spatial distribution of deer and cattle was monitored over 1 year during four trials each lasting 12 days. In each trial six white-tailed deer (three bucks, three does) and nine cows were...

In continuation of the efforts to advance wildfire science and develop tools for wildland fire managers, a spatial wildfire risk assessment was carried out using Classification and Regression Tree analysis (CART) and Geographic Information Systems (GIS). The analysis was performed at two scales. The small-scale assessment covered the entire state of New Mexico, while the large-scale assessment covered only the Middle Rio Grande ecosystem. The result of this project is a Geographic Information System (GIS) based predictive model. The model highlights areas of high wildfire risk, based on...

The perception is that today's large fires are an ecological catastrophe because they burn vast areas with high intensities and severities. However, little is known of the ecological impacts of large fires on both historical and contemporary landscapes. The present paper presents a review of the current knowledge of the effects of large fires in the United States by important ecosystems written by regional experts. The ecosystems are (1) ponderosa pine-Douglas-fir, (2) sagebrush-grasslands, (3) pinon-juniper, (4) chaparral, (5) mixed-conifer, and (6) spruce-fir. This review found that...

The Middle Rio Grande of New Mexico is the most extensive, remaining bosque, or cottonwood forest in the southwest. Alterations caused by humans-damming and channeling the river, controlling floods, and planting non-native trees-have disrupted the cycles of the earlier ecosystem. Without periodic flooding, native cottonwoods cannot regenerate. Invasive exotic plants such as Tamarisk, also known as salt cedar, and Russian olive have filled in the gaps and open spaces, increased fuel loads, and continue to replace native trees and shrubs after wildfires. Cottonwoods, not a fire-adapted...

The Boreal Toad (Bufo boreas boreas) is widely distributed in the western United States but has declined in portions of its range. Research directed at conserving Boreal Toads has indicated that their movements are largely terrestrial and often limited after the breeding season. We used a combination of stream-based netting, PIT tagging, and radio telemetry to examine patterns in captures, movements, and habitat use of Boreal Toads associated with two stream valleys in western Montana. Netting produced 514 captures of 118 adult and 203 juvenile toads from 8 July to 19 August 2003. Juveniles...

This article summarizes information on the taxonomy of 'Appar', a perennial blue flax cultivar (Linum perenne L. [Linaceae]), and characteristics that distinguish it from native Lewis flax (Linum lewisii Pursh [Linaceae]). 'Appar' apparently originated as a European flax that escaped from garden cultivation. Randomly amplified polymorphic DNA (RAPD) analysis places 'Appar' with other collections of European Linum perenne and separates it from native North American collections of Lewis flax. Morphologically, 'Appar' differs from Lewis flax in having an intense blue petal color, shorter...

Bromus tectorum L. (cheatgrass) is the most widespread invasive weed in sagebrushsteppe ecosystems. Invasion by Bromus tectorum produces large-scale changes ecosystem that negatively affect seedling establishment processes. Establishment of invasive and native species plays a key role in determining community invasibility and restoration potential. This study examined factors influencing seedling establishment and survival of Bromus tectorum and native species in ecosystems characterized by different degrees of Bromus tectorum invasion. Temporal and spatial patters of resource availability...

Government agencies, industrial landowners, and private landowners often strive to maintain soil quality after site management activities in order to maintain site productivity, hydrologic function, and ecosystem health. Soil disturbance resulting from timber harvesting, prescribed fire, or site preparation activities can cause declines, improvements, or have no effect on site productivity and hydrologic function. In many cases, detailed soil resource data can be used to determine the stress level and ecosystem health of stands and may be one method used to determine the risk of disease or...

Lynx are quintessential snowshoe hare predators with morphological adaptations such as large paws. This species depends on boreal forests, so the listing of Canada Lynx as a Threatened species is a major conservation issue to forest managers. The U.S. Fish and Wildlife Service stated that human alteration of forest abundance, composition, and connectivity was the most influential factor affecting lynx habitat (Federal Register 63(130):36994-37013). Yet, we do not understand how forest structure and landscape pattern impact the ecology of southern lynx populations. Thus, land managers lack...