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Keyword: United States

A 25-year history of forest disturbance and cause in the United States

Science Spotlights Posted on: September 09, 2015
Understanding trends in forest disturbance caused by fire, harvest, stress, weather, and conversion is important for many forest management decisions as well as scientific investigations. After a decade of collaborative work between the Forest Service, NASA, University of Maryland and other partners, the North American Forest Dynamics (NAFD) project has processed historic Landsat data. This effort provides a comprehensive annual, wall-to-wall analysis of U.S. disturbance history over the last 25 years. Substantial progress has been made to also identify specific causal agents through time, and nationwide datasets will soon be available for exploring spatial and temporal patterns in U.S. forests.

Assessing watershed condition

Projects Posted on: January 21, 2015
Our objective was to develop a consistent nationwide assessment of risk of impaired watershed condition for the nearly 4000 5th-level (10-digit) watersheds containing National Forest System (NFS) land in the contiguous 48 states.

Climate change and wildlife genetics

Science Spotlights Posted on: December 04, 2014
One of the biggest challenges that wildlife and plant populations face is the speed at which climate change is predicted to occur. For some species the rapid rate of change will outpace their ability to migrate to more suitable habitats. What is needed is an understanding of the evolutionary and genetic responses to climate change and accurate identification of which species will be unable to persist given various climatic predictions. Our research will help managers adjust to and reduce the negative impacts of climate change on ecological systems.

Biomass and carbon attributes of downed woody materials in forests of the United States

Publications Posted on: June 24, 2013
Due to burgeoning interest in the biomass/carbon attributes of forest downed and dead woody materials (DWMs) attributable to its fundamental role in the carbon cycle, stand structure/diversity, bioenergy resources, and fuel loadings, the U.S. Department of Agriculture has conducted a nationwide field-based inventory of DWM.

North America [Chapter 5]

Publications Posted on: September 20, 2012
The colonial history of North America presents a contrast between Mexico and the two predominantly English-speaking countries, the United States and Canada. In Mexico, indigenous and other local communities own considerable forested lands, a consequence of the Mexican Revolution of the early twentieth century.

Farmers' objectives toward their woodlands in the upper Midwest of the United States: implications for woodland volumes and diversity

Publications Posted on: April 04, 2012
This paper reports the results of a study that explores the relationship between farm woodland owners' stated intentions for owning woodland, and the structure and composition of these woodlands in the states of Illinois, Indiana and Iowa in the upper Midwest of the United States.

Projected future suitable habitat and productivity of Douglas-fir in western North America

Publications Posted on: March 21, 2012
Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) is one of the most common and commercially important species in western North America. The species can occupy a range of habitats, is long-lived (up to 500 years), and highly productive. However, the future of Douglas-fir in western North America is highly uncertain due to the expected changes in climate conditions.

Combined effects of heat waves and droughts on avian communities across the conterminous United States

Publications Posted on: June 27, 2011
Increasing surface temperatures and climatic variability associated with global climate change are expected to produce more frequent and intense heat waves and droughts in many parts of the world. Our goal was to elucidate the fundamental, but poorly understood, effects of these extreme weather events on avian communities across the conterminous United States.

Heat waves measured with MODIS land surface temperature data predict changes in avian community structure

Publications Posted on: March 22, 2011
Heat waves are expected to become more frequent and severe as climate changes, with unknown consequences for biodiversity. We sought to identify ecologically-relevant broad-scale indicators of heat waves based on MODIS land surface temperature (LST) and interpolated air temperature data and assess their associations with avian community structure.

Effects of drought on avian community structure

Publications Posted on: September 17, 2010
Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioural traits, what time periods and indicators of drought are most relevant, or how response varies geographically at broad spatial scales.