Treesearch

The National Environmental Policy Act (NEPA) requires U.S. Forest Service planning processes to be conducted by interdisciplinary teams of resource specialists to analyze and disclose the likely environmental impacts of proposed natural resource management actions on Forest Service lands. Multiple challenges associated with these processes have been a source of frustration for the agency. One of these challenges involves administrative appeals through which public entities can challenge a Forest Service decision following a NEPA process. These appeals instigate an internal review process...

Forests dominated by Douglas-fir and western hemlock in the Pacific Northwest of the United States have strongly influenced concepts and policy concerning old-growth forest conservation. Despite the attention to their old-growth characteristics, a tendency remains to view their disturbance ecology in relatively simple terms, emphasizing infrequent, stand-replacing (SR) fire and an associated linear pathway toward development of those old-growth characteristics. This study uses forest stand- and age-structure data from 124 stands in the central western Cascades of Oregon to construct a...

This study investigates the effect of projected temperature increases on maritime mountain snowpack in the McKenzie River Basin (MRB; 3041 km2) in the Cascades Mountains of Oregon, USA. We simulated the spatial distribution of snow water equivalent (SWE) in the MRB for the period of 1989–2009 with SnowModel, a spatiallydistributed, process-based model (Liston and Elder, 2006b). Simulations were evaluated using point-based measurements of SWE, precipitation, and temperature that showed Nash-Sutcliffe Efficiency coefficients of 0.83, 0.97, and 0.80, respectively. Spatial accuracy was shown...

Pastoralism has been variously defined in American literary studies. In European literature the pastoral persisted as a distinct genre and self-conscious literary tradition from Theocritus and Virgil through the eighteenth century. Major eighteenth and nineteenth-century American authors alluded to this tradition, but they could not really lay claim to it, for as this essay will argue, the European pastoral was inapplicable to the American setting, both socially and ecologically: socially because although early Anglo-America was by no means a classless society, the distinction between...

Factors influencing soil organic matter (SOM) stabilization and dissolved organic carbon (DOC) content in complex terrain, where vegetation, climate, and topography vary over the scale of a few meters, are not well understood. We examined the spatial correlations of lidar and geographic information system-derived landscape topography, empirically measured soil characteristics, and current and historical vegetation composition and structure versus SOM fractions and DOC pools and leaching on a small catchment (WS1) in the H.J. Andrews Experimental Forest, located in the western Cascades...

Based on regional-scale studies, aboveground production and litter decomposition are thought to positively covary, because they are driven by shared biotic and climatic factors. Until now we have been unable to test whether production and decomposition are generally coupled across climatically dissimilar regions, because we lacked replicated data collected within a single vegetation type across multiple regions, obfuscating the drivers and generality of the association between production and decomposition. Furthermore, our understanding of the relationships between production and decomposit...

Industrial emissions of SO2 and NOx, resulting in the formation and deposition of sulfuric and nitric acids, affect the health of both terrestrial and aquatic ecosystems. Since the mid-late 20th century, legislation to control acid rain precursors in both Europe and the US has led to significant declines in both SO4–S and H + in precipitation and streams. However, several authors noted that declines in streamwater SO4–S did not result in stoichiometric reductions in stream H +, and suggested that observed reductions in base cation inputs in precipitation could lessen the effect of air...

Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade-off possibilities. The competition-defence hypothesis posits a trade-off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth-defence hypothesis suggests that strong competitors for nutrients are also defended against enemies, at a cost to growth rate. We tested these hypotheses using observations of 706 plant populations of over 500 species before and following identical fertilisation and fencing treatments at 39 grassland sites...

Ecosystem-based planning and management have stimulated the need to gather sociocultural values and human uses of land in formats accessible to diverse planners and researchers. Human Ecology Mapping (HEM) approaches offer promising spatial data gathering and analytical tools, while also addressing important questions about human-landscape connections. This article reviews and compares the characteristics of three HEM approaches that are increasingly used in natural resource management contexts, each focused on a particular aspect of human environmental interactions. These aspects include...

Current knowledge concerning the interactions between forest disturbances such as fire and insect defoliation is limited. Wildfires and prescribed burns may influence the intensity and severity of insect outbreaks by affecting the vigor of residual trees, altering aspects of stand structure and abundance of preferred hosts, and by changing the physical environment within forest stands. Prescribed burn timing and frequency are particularly important aspects of the fire regime to consider because they can alter numerous aspects of tree vigor, stand structure, and environmental conditions,...