Treesearch

An increased ability to analyze landscapes in a spatial manner through the use of remote sensing leads to improved capabilities for quantifying human-induced forest fragmentation. Developments of spatially explicit methods in landscape analyses are emerging. In this paper, the image delineation software program eCognition and the spatial pattern analysis program FRAGSTATS were used to quantify patterns of forest fragments on six landscapes across three different climatic regions characterized by different moisture regimes and different influences of human pressure. Our results support the...

Research at the Bob Marshall Wilderness Complex in Montana explored differences in recreation visitors' attitudes towards the use of management-ignited prescribed fires in the wilderness. A mail-back survey of visitors (n = 291) during the 2004 season revealed that over half of visitors would accept prescribed fires in wilderness. This support did not vary by ignition purpose: (a) to restore the natural role of fire or (b) to reduce hazardous fuels and potential for fire escaping to non-wilderness lands. Local visitors, however, were significantly more accepting of prescribed fires than...

We documented the indirect impact of drought-induced mortality of pinyon pine (Pinus edulis) on ground-dwelling arthropod communities. Tree mortality alters microhabitats utilized by ground-dwelling arthropods through increased solar radiation, dead woody debris, and understory vegetation. Our major objectives were to determine if there were differences in species composition, richness and abundance of ground dwelling-arthropods associated with environments experiencing high or low pinyon mortality and whether specific microhabitats could account for differences. We predicted significant...

The changes occurring in mountain regions are an epitome of climate change. The dramatic shrinkage of major glaciers over the past century - and especially in the last 30 years - is one of several iconic images that have come to symbolize climate change.

The Sierra de San Pedro Martir is a mountain range in north-central Baja that comprises the southern-most extension of the Californian coniferous flora, including Pinus jeffreyi, P. contorta, P. lambertiana, Abies concolor, and Calocedrus decurrens. These forests are similar to those in the State of California, with many of the same pathogens present in both the U.S. and Mexico. In the western U.S., attempts to understand the historic roles that pathogens played in forest development and sustainability have been frustrated by more than a century of fire control and logging. The latter have...

In western North America, quaking aspen (Populus tremuloides) is the most common hardwood in montane landscapes. Fire suppression, grazing and wildlife management practices, and climate patterns of the past century are all potential threats to aspen coverage in this region. If aspen-dependent species are losing habitat, this raises concerns about their long-term viability. Though lichens have a rich history as air pollution indicators, we believe that they may also be useful as a metric of community diversity associated with habitat change. We established 47 plots in the Bear River Range...

In recent years the aspen research and management community has witnessed increasing accounts of unexplained aspen die-offs across the Rocky Mountain region. In response, two meetings were held to address the issue; this paper summarizes the most recent gathering, a symposium held in Fort Collins at the USDA Forest Service, Rocky Mountain Research Station, on February 12-13, 2008. This report presents a brief summary of workshop findings along with a synopsis of the state of aspen research in the western United States organized in the following subject categories: SAD case studies,...

Meaningful relationships between forest structure attributes measured in representative field plots on the ground and remotely sensed data measured comprehensively across the same forested landscape facilitate the production of maps of forest attributes such as basal area (BA) and tree density (TD). Because imputation methods can efficiently predict multiple response variables simultaneously, they may be usefully applied to map several structural attributes at the species-level. We compared several approaches for imputing the response variables BA and TD, aggregated at the plot-scale and...

Individual tree detection algorithms can provide accurate measurements of individual tree locations, crown diameters (from aerial photography and light detection and ranging (lidar) data), and tree heights (from lidar data). However, to be useful for forest management goals relating to timber harvest, carbon accounting, and ecological processes, there is a need to assess the performance of these image-based tree detection algorithms across a full range of canopy structure conditions. We evaluated the performance of two fundamentally different automated tree detection and measurement...

Large wildland fires are complex, costly events influenced by a vast array of physical, climatic, and social factors. Changing climate, fuel buildup due to past suppression, and increasing populations in the wildland-urban interface have all been blamed for the extreme fire seasons and rising suppression expenditures of recent years. With each high-cost year comes a multitude of fire cost reviews, suppression cost studies by federal oversight agencies, and new rules and regulations focused on containing or reducing suppression costs. However, largely ignored in many of these inquiries are...