Treesearch

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...

Wildland fire missions can significantly affect regional and global air quality, radiation, climate, and the carbon cycle. A fundamental and yet challenging prerequisite to understanding the environmental effects is to accurately estimate fire emissions. This chapter describes and analyzes fire emission calculations. Various techniques (field measurements, empirical relations, modeling, and remote sensing) to obtain fuel and fire properties are first reviewed. A calculation of fire emissions across the continental U.S. is then illustrated. In this calculation, an approach recently developed...

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...

An inexpensive kit was developed to collect wood samples for molecular detection of pathogenic, saprotrophic and stain fungi in declining Pinus resinosa in the Upper Midwest. The kit contained materials for "clean" collection of sapwood drill shavings, which were then subjected to PCR of the rDNA ITS region with fungal-specific primers, followed by cloning and sequencing. Twenty-seven stands with declining P. resinosa lacking obvious fungal fruiting bodies were sampled by natural resources personnel throughout MN, WI, and MI. No single mortality agent predominated and causal agent(s)...

The Center for Forest Mycology Research (CFMR), U.S. Forest Service, Northern Research Station, Madison, WI, is home to the world's largest collection of wood-inhabiting fungi. These collections constitute a library of the fungal kingdom that is used by researchers thoughout the world. The CFMR collections have many practical uses that have improved the lives of Americans directly and indirectly over the past century in many ways. The CFMR and its collections contribute to tools to: identify and manage devastating fungal diseases of trees and wildlife, understand and maintain endangered...

Over the last century, the United States has evolved from a predominantly rural to an urbanized society with an exurban area currently referred to as the wildland urban interface (WUI). This WUI is critical as it occupies three to five times as much land area as urban areas with emerging and latent conflicts between traditional resource management and preferences of new residents. The effect of development on wildland fire management has received the most attentions. Increasingly, one of the most effective tools in the manger's kit, fuel reduction by frequent understory burning, is...

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...