Treesearch

To explore thermal regimes and hydrologic capacity of rock glaciers and related periglacial talus landforms, mini-thermochrons were deployed in and around potentially ice-embedded features of the Sierra Nevada. Results from pilot studies at 13 rock glaciers and 7 taluses indicate that outlet springs from these landforms generally do not desiccate but persist year-round as ice (frozen) in winter and flowing water in the warm season. Temperatures of water (liquid and ice) in rock-glacier outlet springs had an annual mean of -0.2 °C and mean of 0.6 °C during the warm season with very low...

Electronic-nose (e-nose) instruments, derived from numerous types of aroma-sensor technologies, have been developed for a diversity of applications in the broad fields of agriculture and forestry. Recent advances in e-nose technologies within the plant sciences, including improvements in gas-sensor designs, innovations in data analysis and pattern-recognition algorithms, and progress in material science and systems integration methods, have led to significant benefits to both industries. Electronic noses have been used in a variety of commercial agricultural-related industries, including...

Large-scale inventories of downed woody debris (DWD; downed dead wood of a minimum size) often record decay status by assigning pieces to classes of decay according to their visual/structural attributes (e.g., presence of branches, log shape, and texture and color of wood). DWD decay classes are not only essential for estimating current DWD biomass and carbon stocks, but may also facilitate the prediction of future DWD attributes. Estimating temporal transitions between decay classes may provide a mechanism for projecting DWD attributes in forest ecosystems. To date, modeling decay class...

The objectives of this study were to assess susceptibility to acidification and nitrogen (N) saturation caused by atmospheric deposition to northeastern US forests, evaluate the benefits and shortcomings of making critical load assessments using regional data, and assess the relationship between expected risk (exceedance) and forest health. We calculated the critical loads of nutrient N and of sulfur (S)+N using the steady-state mass balance method at >4,000 regional and national vegetation and soil monitoring network plots in the northeastern USA. Regional calculations of critical loads...

Our interest in reshaping the natural world to enhance human life can be traced back thousands of years to the earliest urban civilizations. From irrigation projects of the Indus Valley to the Roman aqueducts to designing integrated systems of landscaped parks and stream valleys, humans have sought to harness the capacity of nature to advance public well-being, prosperity and urban development. Throughout this history one finds a wide range of social actors in competition over urban land not only as it becomes scarce but as the meaning of nature shifts in concert with changing social and...

Over the past 60 years, housing growth has outpaced population growth in the United States. Conservationists are concerned about the far-reaching environmental impacts of housing development, particularly in rural areas. We use clustering analysis to examine the pattern and distribution of housing development since 1940 in and around the Northern Forest, a heavily forested region with high amenity and recreation use in the Northeastern United States. We find that both proximity to urban areas and an abundance of natural amenities are associated with housing growth at the neighborhood level...

The U.S. has been providing national-scale estimates of forest carbon (C) stocks and stock change to meet United Nations Framework Convention on Climate Change (UNFCCC) reporting requirements for years. Although these currently are provided as national estimates by pool and year to meet greenhouse gas monitoring requirements, there is growing need to disaggregate these estimates to finer scales to enable strategic forest management and monitoring activities focused on various ecosystem services such as C storage enhancement. Through application of a nearest-neighbor imputation approach,...

Urban and community forests play an important role in the overall carbon budget of the USA. Accurately quantifying carbon sequestration by these forests can provide insight for strategic planning to mitigate greenhouse gas effects on climate change. This study provides a new methodology to estimate net forest carbon sequestration (FCS) in urban and community lands of northern New England using ground based forest growth rates, housing density data, satellite derived land cover and tree canopy cover maps at the county level. We estimated that the region’s urban and community forests...

Forest treatments have the potential to produce significant quantities of forest residue biomass, which includes the tops and limbs from merchantable trees and smaller trees removed to meet management objectives. We spatially analyzed the sensitivity of financially feasible biomass volumes for delivery to a bioenergy facility across 16 combinations of delivered biomass and diesel prices for a 515,900 ha area in western Montana. At the lowest delivered biomass price analyzed, $31.52 per oven dried tonne (ODT), 28% of the potential volume was financially feasible at the lowest diesel price,...

Thermochemical biomass conversion systems have the potential to produce heat, power, fuels and other products from forest biomass at distributed scales that meet the needs of some forest industry facilities. However, many of these systems have not been deployed in this sector and the products they produce from forest biomass have not been adequately described or characterized with regards to chemical properties, possible uses, and markets. This paper characterizes the producer gas, biochar, and activated carbon of a 700 kg h-1 prototype gasification system and a 225 kg h-1 pyrolysis system...