Treesearch

Assessing landscape patterns in climate vulnerability, as well as resilience and resistance to drought, disturbance, and invasive species, requires appropriate metrics of relevant environmental conditions. In dryland systems of western North America, soil temperature andmoisture regimes have been widely utilized as an indicator of resilience to disturbance and resistance to invasive plant species by providing integrative indicators of long-term site aridity, which relates to ecosystem recovery potential and climatic suitability to invaders. However, the impact of climate change on these...

Wyoming big sagebrush is a widely distributed shrub that is native to the western United States. It occupies the largest area of the big sagebrush cover types. Wyoming big sagebrush ecosystems support hundreds of plant and animal species, including sage-grouse and many other sagebrush obligates, and Wyoming big sagebrush may be the single most important plant to sage-grouse. Its distribution has been reduced since European-American settlement, and it may become further reduced or altered by changes in fire regimes, spread of nonnative plants, conifer expansion, climate changes, and other...

Forest management, especially restoration, is informed by understanding the dominant natural disturbance regime. In many western North American forests the keystone disturbance is fire, and much research exists characterizing various fire regime parameters, although often only one or two parameters are addressed in individual studies. I performed a systematic review of the literature and meta-analysis of the derived data from 26 publications to characterize five parameters of the historical fire regime of ponderosa pine ecosystems in Colorado: fire frequency, severity, extent, seasonality,...

This synthesis summarizes information available in the scientific literature on historical patterns and contemporary changes in fuels and fire regimes in juniper communities of the Columbia and northern Great basins. Limited evidence suggests that many presettlement juniper woodlands and savannas had open stand structures, and they typically occurred in claypan soils or shallow soils on rocky sites. Few fire history studies have been conducted in these regions, and sample sizes were small and methodologies challenging, so historical fire regimes are poorly understood. Information was...

Wildfires and prescribed fires cause a range of impacts on forest soils depending on the interactions of a nexus of fire severity, scale of fire, slope, infiltration rates, and post-fire rainfall. These factors determine the degree of impact on forest soils and subsequently the need for post-fire soil management. Fire is a useful tool in landscape management but it can be benign or set off serious deteriorations in soil quality that lead to long-term desertification. If parts of the nexus are absent or not inherently risky, forest soil impacts can be relatively minor or nonexistent. A low...

Wildfires commonly increase nutrient, carbon, sediment and metal inputs to streams, yet the factors responsible for the type, magnitude and duration of water quality effects are poorly understood. Prior work by the current authors found increased nitrogen, phosphorus and cation exports were common the first 5 post-fire years from a synthesis of 159 wildfires across the western United States. In the current study, an analysis is undertaken to determine factors that best explain post-fire streamwater responses observed in those watersheds. Increased post-fire total nitrogen and phosphorus...

Western juniper occurs in the Pacific Northwest, California, and Nevada. Old-growth western juniper stands that established in presettlement times (before the 1870s) occur primarily on sites of low productivity such as claypan soils, rimrock, outcrops, the edges of mesas, and upper slopes. They are generally very open and often had sparse understories. Western juniper has established and spread onto low slopes and valleys in many areas, especially areas formerly dominated by mountain big sagebrush. These postsettlement stands (woodland transitional communities) are denser than most...

Plant modularity traits relevant to functions of on-spot persistence, space occupancy, resprouting after disturbance, as well as resource storage, sharing, and foraging have been underrepresented in functional ecology so far. This knowledge gap exists for multiple reasons. First, these functions and related traits have been considered less important than others (e.g., resource economics, organ-based traits). Second, collecting data for modularity traits can be difficult. Third, as a consequence of the previous points, there is a lack of standardized collection protocols. We now feel the...

The Great Plains Grassland Summit: Challenges and Opportunities from North to South was held April 10-11, 2018 in Denver, Colorado to provide syntheses of information about key grassland topics of interest in the Great Plains; networking and learning channels for managers, researchers, and stakeholders; and working sessions for sharing ideas about challenges and future research and management opportunities. The summit was convened to better understand stressors and resource demands throughout the Great Plains and how to manage them, and to discuss methods for improved collaboration among...

Local land managers are tasked with balancing the needs and preferences of local and national publics. This report provides a snapshot of preferences for local public land management and the demographics of communities within 50 miles of U.S. national forests and grasslands in the Northern Region of the U.S. Forest Service. This information is important for managers because understanding the preferences of different user groups is essential as they seek to manage for multiple uses and balance distinct interests. This information can be used to: (a) inform project and forest planning, (b)...