Treesearch

It is often necessary to find a simpler method in different climatic regions to calculate reference crop evapotranspiration (ETo) since the application of the FAO-56 Penman-Monteith method is often restricted due to the unavailability of a comprehensive weather dataset. Seven ETo methods, namely the standard FAO-56 Penman-Monteith, the FAO-24 Radiation, FAO-24 Blaney Criddle, 1985 Hargreaves, Priestley-Taylor, 1957 Makkink, and 1961 Turc, were applied to calculate monthly averages of daily ETo, total annual ETo, and daily ETo in an arid region at Aksu, China, in a semiarid region at...

Habitat selection is a fundamental component of community ecology, population ecology, and evolutionary biology and can be especially important to species with complex annual habitat requirements, such as migratory birds. Resource preferences on the breeding grounds may change during the postfledging period for migrant songbirds, however, the degree to which selection changes, timing of change, and whether all or only a few species alter their resource use is unclear. We compared resource selection for nest sites and resource selection by postfledging juvenile ovenbirds (Seiurus aurocapilla...

Many invasive plant species show high rates of nutrient acquisition relative to their competitors. Yet the mechanisms underlying this phenomenon, and its implications for ecosystem functioning, are poorly understood, particularly in nutrient-limited systems. Here, we test the hypothesis that an invasive plant species (Microstegium vimineum) enhances its rate of nitrogen (N) acquisition by outcompeting soil organic matter-degrading microbes for N, which in turn accelerates soil N and carbon (C) cycling. We estimated plant cover as an indicator of plant N acquisition rate and quantified...

The growing demand for renewable, carbon-neutral materials and energy is leading to intensified forest land-use. The long-term ecological challenges associated with maintaining soil fertility in managed forests are not yet known, in part due to the complexity of soil microbial communities and the heterogeneity of forest soils. This study determined the long-term effects of timber harvesting, accompanied by varied organic matter (OM) removal, on bacterial and fungal soil populations in 11- to 17-year-old reforested coniferous plantations at 18 sites across North America. Analysis of highly...

The goal of this study was to update life-cycle assessment (LCA) data on I-joist production in the southeast (SE) region of the United States. The authors collected primary mill data from I-joist production facilities per Consortium on Research for Renewable Industrial Materials (CORRIM) research guidelines. Comparative assertions were not a goal of this study.

Natural resource professionals are often tasked with weighing the benefits and costs of changes in ecosystem services associated with land management alternatives and decisions. In many cases, federal regulations even require land managers and planners to account for these values explicitly. Outdoor recreation is a key ecosystem service provided by national forests and grasslands, and one of significant interest to the public. This report presents the most recent update of the Recreation Use Values Database, based on an exhaustive review of economic studies spanning 1958 to 2015 conducted...

A pattern of increasing frequency and intensity of heavy rainfall over land has been documented for several temperate regions and is associated with climate change. This study examines the changing patterns of daily precipitation at the Coweeta Hydrologic Laboratory, North Carolina, USA, since 1937 for four rain gauges across a range of elevations. We analyse seasonal total rainfall, number of rain days and the frequency of heavy rainfall. We compare these with several teleconnections, including the Bermuda High Index (BHI), the West BHI, the North Atlantic Oscillation (NAO) and the El...

Canopy transpiration (EC) is a large fraction of evapotranspiration, integrating physical and biological processes within the energy, water, and carbon cycles of forests. Quantifying EC is of both scientific and practical importance, providing information relevant to questions ranging from energy partitioning to ecosystem services, such as primary productivity and water yield. We estimated EC of four pine stands differing in age and growing on sandy soils. The stands consisted of two wide-ranging conifer species: Pinus taeda and Pinus sylvestris, in temperate and boreal zones, respectively....

Southeast Alaska is a remote area, located approximately 700 miles north of Seattle, Washington. Most of the region’s goods are imported by barge, creating logistical and economic challenges not faced by many other parts of the United States. In this context, we used life cycle assessment (LCA) to evaluate the potential environmental impact on global warming potential (GWP) of converting home heating systems from heating oil to wood pellets in southeast Alaska. Once the current level (status quo) was established, we evaluated imported pellet utilization at 20-, 40- and 100-percent penetrati...

The fire characteristics chart is a graphical method of presenting U.S. National Fire Danger Rating System (NFDRS) indexes and components as well as primary surface or crown fire behavior characteristics. Computer software has been developed to produce fire characteristics charts for both fire danger and fire behavior in a format suitable for inclusion in reports and presentations. Scales, colors, labels, and legends can be modified as needed. The fire characteristics chart for fire behavior has been described previously (Andrews et al. 2011). This report describes the fire characteristics...