Pasar al contenido principal

page search

Displaying 1165 - 1176 of 1735
Journal Articles & Books
Diciembre 2011

This study examined changes in never-harvested mixed conifer (MCF), spruce-fir (SFF), and quaking aspen forests (QAF) in Grand Canyon National Park (GCNP), Arizona, USA based on repeat sampling of two sets of vegetation study plots, one originally sampled in 1935 and the other in 1984. The 1935…

Journal Articles & Books
Diciembre 2011

The hemlock woolly adelgid is an invasive insect that is damaging hemlock forests in the eastern United States. Several control methods are available but forest managers are constrained by cost, availability, and environmental concerns. As a result forest managers must decide how to allocate…

Journal Articles & Books
Diciembre 2011

Livestock grazing is an important form of land use, affecting ecosystems worldwide. In ecoregions that evolved with low densities of large ungulates, such as those in the western United States, there is ongoing debate as to the appropriate concentrations of livestock that can be sustained.…

Journal Articles & Books
Diciembre 2011

- Brook charr (Salvelinus fontinalis) is a sentinel fish species that requires clean, cold water habitats generally resulting from landscapes that allow for surface water flows devoid of sediment and contaminants and high groundwater discharge of cold water. As such, brook charr are impacted by…

Journal Articles & Books
Diciembre 2011

Carbon capture and storage (CCS) is considered by some to be a promising technology to reduce greenhouse gas emissions, and advocates are seeking policies to facilitate its deployment. Unlike many countries, which approach the development of policies for geologic storage (GS) of carbon dioxide (…

Journal Articles & Books
Diciembre 2011

Photography has been a welcome tool in documenting and conveying qualitative soil information. When coupled with image analysis software, the usefulness of digital cameras can be increased to advance the field of micropedology. The determination of a representative elementary area (REA) still…

Journal Articles & Books
Diciembre 2011

Tidal salt marshes in the San Francisco Estuary region display heterogeneous vegetation patterns that influence wetland function and provide adequate habitat for native or endangered wildlife. In addition to analyzing the extent of vegetation, monitoring the dynamics of vegetation pattern within…

Journal Articles & Books
Diciembre 2011

Birds pose serious hazards at United States airports because of the potential for collisions with aircraft. Raptors, in particular, are hazardous to aircraft safety due to their size, hunting behavior, and hovering and soaring habits. Reduction of rodent populations at an airport may decrease…

Journal Articles & Books
Diciembre 2011

Improvement in remote sensing techniques in spatial/spectral resolution strengthens their applicability for urban environmental study. Unfortunately, high spatial resolution imagery also increases internal variability in land cover units and can cause a ‘salt-and-pepper’ effect, resulting in…

Journal Articles & Books
Diciembre 2011

Suburban areas continue to grow rapidly and are potentially an important land-use category for anthropogenic carbon-dioxide (CO₂) emissions. Here eddy covariance techniques are used to obtain ecosystem-scale measurements of CO₂ fluxes (FC) from a suburban area of Baltimore, Maryland, USA (2002–…

Conference Papers & Reports
Diciembre 2011

Many communities in the United States face the decision about whether to protect or restore forests on environmentally sensitive sites. The objective of this research is to identify priority areas for forest landscape restoration in Knox County, Tennessee. A cost-benefit analysis is conducted to…

Journal Articles & Books
Diciembre 2011

Kudzu—Pueraria montana var. lobata (Willd.)—was initially planted in the southern United States and subsequently spread throughout the countryside following changes in land use. Kudzu covers more than 2.8 million ha which prevents uses such as timber production and establishment of carbon…