Treesearch

Mount St. Helens National Volcanic Monument was designated by the U.S. Congress in 1982 to conserve the landscape for natural regeneration, scientific research, education, and cultural resource preservation. However, this designation has not eliminated threats from the introduction of non-native species. The non-native New Zealand mud snail (NZMS), Potamopyrgus antipodarum, was first observed in 2016 along the SW shore of Spirit Lake at the foot of Mount St. Helens, despite the lake’s closure to public recreation and isolation from other known sites harboring NZMS. Our study mapped native...

Uncertainty, complexity, and dynamic changes present challenges for conservation and natural resource management. Evidence-based approaches grounded in reliable information and rigorous analysis can enhance the navigation of the uncertainties and trade-offs inherent in conservation problems. This study highlights the importance of collaborative efforts and evidence-based decision-making, specifically implementing the Resilience-Experimentalist school of adaptive management (RE-ARM), which emphasizes stakeholder involvement, shared understanding, and experimentation. Our goal was to develop...

1. Biological assemblages in streams are influenced by hydrological dynamics, particularly in non-perennial systems. Although there has been increasing attention on how drying impacts stream organisms, few studies have investigated how specific characteristics of drying and subsequent wetting transitions influence biotic responses via resistance and resilience traits. 2. Here, we characterized how hydrologic metrics, including those quantifying drying and wetting transitions as well as dry and wet phases, alter diversity and composition of three aquatic assemblages in non-perennial streams...

Temperate forests, characterized by cyclical annual climate with distinct seasons, occur in some of the most densely populated regions of the world. Societies depend on these forests to provision ecosystem services such as timber, water, recreation, and cultural resources. However, climate change threatens the health and continued provisioning of the critical services these forests supply. In this chapter, we provide an overview of observed and projected climate change effects on temperate forests, with a focus on disturbance, ecosystem shifts, and ecosystem services. We provide context...

Distributions of both native and invasive species are expected to shift under future climate. Species distribution models (SDMs) are often used to explore future habitats, but sources of uncertainty including novel climate conditions may reduce the reliability of future projections. We explore the potential spread of the invasive annual grass ventenata (Ventenata dubia) in the western United States under both current and future climate scenarios using boosted regression tree models and 30 global climate models (GCMs). We quantify novel climate conditions, prediction variability arising...

Changing climatic conditions are increasing overstory tree mortality in forests globally. This restructuring of the distribution of biomass is making already flammable forests more combustible, posing a major challenge for managing the transition to a lower biomass state. In western US dry conifer forests, tree density resulting from over a century of fire-exclusion practices has increased the risk of high-severity wildfire and susceptibility to climate-driven mortality. Reducing dead fuel loads will require new approaches to mitigate risk to the remaining live trees by preparing forests...

We examined the interactions between stream water and subsurface sediment to quantify how these interactions influenced organic C respiration and dissolved inorganic C (DIC) production in the hyporheic zone of a high-gradient headwater mountain stream draining a forested catchment at the H. J. Andrews Experimental Forest, Oregon, USA. We compared measurements from a well network with those from six 2-m-long hyporheic mesocosms. The patterns in hyporheic metabolism were similar in wells and mesocosms: O2 declined and DIC increased with travel time. However, the dissolved organic C (DOC)...

Forest vegetation mapping that integrates forest inventory data with multispectral remote sensing data provides valuable geospatial products for public land management agencies, but resource managers may require rapid updating of maps as new imagery becomes available (updating) or retrospective mapping for times prior to forest inventory plot measurement (hindcasting). While forest attribute mapping using Landsat multispectral imagery is common, the accuracy of applying models outside of reference epoch to support long-term forest monitoring is not normally quantified. We examine whether a...

Freshwater turtles are important components of wetland ecosystems, but few studies have assessed the quality of created and restored wetlands for turtles. We determined whether habitat characteristics and abundance, body condition, adult sex ratio, and mean adult size of two turtle species, Painted Turtles (Chrysemys picta) and Snapping Turtles (Chelydra serpentina), differed between 16 restored and 16 reference wetlands in West Virginia, USA, and quantified the influence of habitat characteristics on abundance and body condition. At each wetland, we measured habitat characteristics and...

We quantified temporal dynamics of wood storage, input, and transport over a 24-year period in adjacent old-growth and second-growth forested reaches in Mack Creek, a third-order stream in the Cascade Range of Oregon. The standing stocks of large wood in the old-growth reach exceeded those at the second-growth reach by more than double the number of wood pieces and triple the wood volume. Annual inputs of large wood were highly variable. Wood numbers delivered into the old-growth reach were 3× higher and wood volume 10× greater than in the second-growth reach. The movement of number and...