Treesearch

The annual national report of the Forest Health Monitoring (FHM) Program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation Monitoring projects funded through the FHM national program. In this 17th edition in a series of annual reports, national survey data are used to identify geographic patterns of insect and disease activity. Satellite data are...

Forests cover a vast area of the United States, 304 million ha or approximately one-third of the Nation’s land area (Smith and others 2009). These forests possess the capacity to provide a broad range of goods and services to current and future generations, to safeguard biological diversity, and to contribute to the resilience of ecosystems, societies, and economies (USDA Forest Service 2011). Their ecological roles include supplying large and consistent quantities of clean water, preventing soil erosion, and providing habitat for a broad diversity of plant and animal species. Their...

Insects and diseases cause changes in forest structure and function, species succession, and biodiversity, which may be considered negative or positive depending on management objectives (Edmonds and others 2011). An important task for forest managers, pathologists, and entomologists is recognizing and distinguishing between natural and excessive mortality, a taskthat relates to ecologically based or commoditybased management objectives (Teale and Castello 2011). The impacts of insects and diseases on forests vary from natural thinning to extraordinary levels of tree mortality, but insects...

As a pervasive disturbance agent operating at many spatial and temporal scales, wildland fire is a key abiotic factor affecting forest health both positively and negatively. In some ecosystems, for example, wildland fires have been essential for regulating processes that maintain forest health (Lundquist and others 2011). Wildland fire is an important ecological mechanism that shapes the distributions of species, maintains the structure and function of fire-prone communities, and acts as a significantevolutionary force (Bond and Keeley 2005). At the same time, wildland fires have created...

Droughts affect most forested ecosystems of the United States, but they vary widely in frequency and intensity (Hanson andWeltzin 2000). Most western U.S. forests experience annual seasonal droughts, with the seasonality determined by broadscaleatmospheric circulation patterns and topography. For example, forests along the Pacific Coast usually experience dry summers and wet winters, while forests in Arizona and western New Mexico rely in part on rainfallreceived during a summer monsoon season (Adams and Comrie 1997, Hanson and Weltzin 2000). In contrast, eastern U.S. forests typically...

The 1994 Northwest Forest Plan (NWFP) was developed to resolve debates over old-growth forests, endangered species, and timber production on federal forests in the range of the northern spotted owl. This three-volume science synthesis, which consists of 12 chapters that address various ecological and social concerns, is intended to inform forest plan revision and forest management within the NWFP area. Land managers with the U.S. Forest Service provided questions that helped guide preparation of the synthesis, which builds on the 10-, 15-, and 20-year NWFP monitoring reports and synthesizes...

The rapid and extensive expansion of emerald ash borer (EAB) in North America since 2002 may eliminate most existing ash stands, likely affecting critical ecosystem services associated with water and carbon cycling. To our knowledge, no studies have evaluated the coupled response of black ash (Fraxinus nigra Marsh.) wetland water tables, soil temperatures, and soil gas fluxes to an EAB infestation. Water table position, soil temperature, and soil CO2 and CH4 fluxes were monitored in nine depressional headwater black ash wetlands in northern Michigan. An EAB disturbance was simulated by...

This publication is part of a series of that provides an overview of the presence of invasive plant species monitored on an extensive systematic network of plots measured by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service, Northern Research Station (NRS). Each research note features one of the invasive plants monitored on forested plots by NRS FIA in the 24 states of the Midwestern and Northeastern United States. Common buckthorn (Rhamnus cathartica; also known as European buckthorn) is a woody shrub that is native to Eurasia and was introduced to North America...

The worldwide decline of large carnivores is concerning, particularly given the important roles they play in shaping ecosystems and conserving biodiversity. Estimating the capacity of an ecosystem to support a large carnivore population is essential for establishing reasonable and quantifiable recovery goals, determining how population recovery may rely on connectivity, and determining the feasibility of investing limited public resources toward recovery. We present a case study that synthesized advances in habitat selection and spatiallyexplicit individual-based population modeling, while...