Treesearch

Environmental DNA (eDNA) assays for single‐ and multi‐species detection show promise for providing standardized assessment methods for diverse taxa, but techniques for evaluating multiple taxonomically divergent assemblages are in their infancy. We evaluated whether microfluidic multiplex metabarcoding on the Fluidigm Access Array™ platform and high‐throughput sequencing could identify diverse stream and riparian assemblages from 48 taxon‐general and taxon‐specific metabarcode primers. eDNA screening was paired with electrofishing along a stream continuum to evaluate congruence between...

The Southwest Washington Adaptation Partnership (SWAP) was developed to identify climate change issues relevant for resource management in southwest Washington, specifically on Gifford Pinchot National Forest. This science-management partnership assessed the vulnerability of natural resources to climate change and developed adaptation options that minimize negative impacts of climate change on resources of concern and facilitate transition of diverse ecosystems to a warmer climate. The vulnerability assessment focuses on fish and aquatic habitat, vegetation, special habitats, recreation,...

The shoreline in southeast Alaska is changing. In many places, the shoreline is rising as glaciers melt and the land rebounds; elsewhere, rising sea levels are submerging the current shoreline. These changes are altering coastal habitats and subsistence resources on which many rural Alaska Native communities rely in southeast Alaska.Forest Service scientists Adelaide Johnson and Linda Kruger modeled the relationships between physical shoreline features and biological communities to project future shorelines and the distribution of food resources. They also engaged high school students from...

One of the desired outcomes of dam decommissioning and removal is the recovery of aquatic and riparian ecosystems. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological links driving ecological responses to removing dams. We define models for three distinct spatial domains: upstream of the former reservoir, within the reservoir, and downstream of the removed dam. Emerging from these models are response trajectories that clarify potential pathways of ecological transitions...

Public officials and stakeholders who want to advance watershed protection may want to consider how ballot referendum design can serve as a nudge in voting behaviors. We extend the research literature on voter preferences by using behavioral economics theory to provide new insights into voter behaviors towards watershed conservation referendums. We drew upon observations from 76 separate watershed protection referendums, conducted in the eastern U.S. from 1991 to 2013, and evaluated the wording of the ballot statement to determine their potential influence on voter support and the psycholog...

Many climate change models predict increases in frequency and magnitude of temperature fluctuations that might impact how ectotherms are affected by disease. Shifts in temperature might especially affect amphibians, a group with populations that have been challenged by several pathogens. Because amphibian hosts invest more in immunity at warmer than cooler temperatures and parasites might acclimate to temperature shifts faster than hosts (creating lags in optimal host immunity), researchers have hypothesized that a temperature shift from cold-to-warm might result in increased amphibian...

This report highlights significant research findings and accomplishments of the Pacific Northwest Research Station during fiscal year 2018.

In the Pacific Northwest, clearcutting is the preferred method for harvesting wood products from Douglas-fir plantations because it’s economical and mimics a large-scale disturbance. Following a clearcut, Douglas-fir seedlings are planted throughout the recovering native plant community. Yet the newly planted seedlings and native plants aren’t the only vegetation claiming the open ground. Invasive plant species, such as Scotch broom and sweet vernalgrass, can also colonize the site and compete with the seedlings for water, nutrients, and light.Eradicating Scotch broom requires repeated...

A century of fire suppression across the Western United States has led to more crowded forests and increased competition for resources. Studies of forest thinning or stand conditions after mortality events have provided indirect evidence for how competition can promote drought stress and predispose forests to severe fire and/or bark beetle outbreaks. Here, we demonstrate linkages between fire deficits and increasing drought stress through analyses of annually resolved tree‐ring growth, fire scars, and carbon isotope discrimination (Δ13C) across a dry mixed‐conifer forest landscape. Fire...

The iso/anisohydry concept characterizes plants according to their water status regulation. Coexisting definitions and misconceptions have recently led to considerable criticism. Here, we discuss reasons for the misconceptions and propose a robust definition of iso/anisohydry using the leaf turgor loss point to integrate the complex interplay of plant hydraulic traits.