Treesearch

The loss of open space was declared one of the “four threats to the health of our nation’s forests” by former USDA Forest Service Chief Dale Bosworth in 2004. Since then, the agencywide Open Space Conservation Strategy (OSCS) was released and the “four threats” were incorporated into the agency’s National Strategic Plan. These actions indicate that the OSCS is in the implementation stage of the policy process; however, interviews conducted with line officers and program managers of the National Forest System (NFS) in Washington State revealed a more complex story. This research uses...

Climate change is expected to change the distribution of species. For long-lived, sessile species such as trees, tracking the warming climate depends on seedling colonization of newly favorable areas. We compare the distribution of seedlings and mature trees for all but the rarest tree species in California, Oregon and Washington, United States of America, a large, environmentally diverse region. Across 46 species, the mean annual temperature of the range of seedlings was 0.120°C colder than that of the range of trees (95% confidence interval from 0.096 to 0.144°C). The extremes of the...

Soil erosion has significant implications for land productivity and surface water quality, as sediment is the leading water pollutant worldwide. Here, erosion processes are defined. The dominant factors influencing soil erosion in humid areas are reviewed, with an emphasis on the roles of precipitation, soil moisture, soil porosity, slope steepness and length, vegetation, and soil organisms. Erosion dynamics in forested watersheds are the focus with some examples from agricultural watersheds included as well. Lastly, best management practices for controlling surface erosion are discussed.

This is a primer about hydrology, the science of water. Watersheds are the basic land unit for water resource management and their delineation, importance, and variation are explained and illustrated. The hydrologic cycle and its components (precipitation, evaporation, transpiration, soil water, groundwater, and streamflow) which collectively provide a foundation for how landscapes and water interact are discussed at length. Important hydrologic concepts and methods are described in detail but primarily within the context of forested watersheds since most of the nation's fresh water...

Over the last few decades, considerable attention has focused on small-scale studies of invasive plants and invaded systems. Unfortunately, small scale studies rarely provide comprehensive insight into the complexities of biological invasions at macroscales. Systematic and repeated monitoring of biological invasions at broad scales are rare. In this report, we highlight a unique invasive plant database from the national Forest Inventory and Analysis (FIA) program of the United States Forest Service. We demonstrate the importance and capability of this subcontinental-wide database by...

Land management agencies commonly use rapid assessments to evaluate the impairment of gravel-bed streams by sediment inputs from anthropogenic sources. We question whether rapid assessment can be used to reliably judge sediment impairment at a site or in a region. Beyond the challenges of repeatable and accurate sampling, we argue that a single metric or protocol is unlikely to reveal causative relations because channel condition can result from multiple pathways, processes, and background controls. To address these concerns, a contextual analysis is needed to link affected resources,...

1.Because of their longevity and skeletal phosphorus demand, vertebrates can have distinct influences on the uptake, storage and recycling of nutrients in ecosystems. Quantification of body stoichiometry, combined with estimates of abundance or biomass, can provide insights into the effect of vertebrates on nutrient cycling. 2.We measured the nutrient content and estimated the abundance and biomass of the larvae of three salamander species to characterise the factors that influence larval salamander stoichiometry and estimate the contribution of larval salamanders to nutrient standing...

Evapotranspiration (ET) is arguably the most uncertain ecohydrologic variable for quantifying watershed water budgets. Although numerous ET and hydrological models exist, accurately predicting the effects of global change on water use and availability remains challenging because of model deficiency and/or a lack of input parameters. The objective of this study was to create a new set of monthly ET models that can better quantify landscape-level ET with readily available meteorological and biophysical information. We integrated eddy covariance flux measurements from over 200 sites, multiple...

Whether used to support or impede action, scientific knowledge is now, more than ever, the primary framework for political discourse on climate change. As a consequence, science has become a hegemonic way of knowing climate change by mainstream climate politics, which not only limits the actors and actions deemed legitimate in climate politics but also silences vulnerable communities and reinforces historical patterns of cultural and political marginalization. To combat this “post-political” condition, we seek to democratize climate knowledge and imagine the possibilities of climate praxis...

Riparian habitats provide detrital subsidies of varying quantities and qualities to recipient ecosystems. We used long-term data from three reference streams (covering 24 stream-years) and 13-year whole-stream organic matter manipulations to investigate the influence of terrestrial detrital quantity and quality on benthic invertebrate community structure, abundance, biomass, and secondary production in rockface (RF) and mixed substrates (MS) of forested headwater streams. Using a mesh canopy covering the entire treatment stream, we examined effects of litter exclusion, small- and large-wood...