Treesearch

Monitoring vegetation phenology is important for managers at several scales. Across decades, changes in the timing, pattern, and duration of significant life cycle events for plant groups can foreshadow shifts in species assemblages that can affect ecosystem services. In the shorter term, managers need phenological information to time activities such as grazing, ecological restoration plantings, biocontrol of pests, seed collection, and wildlife monitoring. However, tools to deliver timely seasonal development have been limited either spatially (data from a single tower or weather station,...

A recent expansion in wood energy use at schools in Alaska has resulted in more than a dozen wood energy systems in operation. However, few have been evaluated for fuel efficiency and pollution impacts, both of which can be examined via combustion gas analysis. In this research, we monitored the wood energy system at a public school during winter heating conditions. Wood energy parameters were sampled on three occasions during early, mid, and late winter in northern Alaska. Combustion gas was sampled for a range of parameters that indicated boiler performance, including gas emmissions of...

This report highlights key findings from 2013 data collected by the U.S. Department of Agriculture, Forest Service, Forest Inventory and Analysis program across all forested land on Guam, updating findings from data collected in 2002 that were published in Resource Bulletin PNW-RB-243. We summarize and interpret basic resource information such as estimates of forest area, stem volume, biomass, number of trees, damages to trees, and tree size distribution, as well as overstory and understory vegetation cover and information on invasive plant species presence and cover. Detailed tables and...

For decades, federal, state, and nonprofit organizations have been working to restore freshwater habitat for Oregon coastal coho salmon (Oncorhynchus kisutch), a species listed as threatened under the federal Endangered Species Act. Much of the restoration, however, has been done without directly considering the availability and connectivity of seasonally important freshwater habitats. Research by Rebecca Flitcroft, a research fish biologist with the U.S. Forest Service Pacific Northwest Research Station, and colleagues reveals that connectivity among different types of freshwater habitat...

A growing body of research shows that plant genetic factors can influence ecosystem processes and structure communities, but one aspect that has received little study is sex differentiation in dioecious plants. Since headwater streams are reliant on riparian leaf litterfall, plant sex differences in leaf traits may influence in-stream processes. Sitka willow (Salix sitchensis) at Mount St. Helens is dioecious and heavily infested with the stem-boring weevil (Cryptorhynchus lapathi), which causes branch dieback and summer litterfall. We found that female willow shrubs tend to grow closer to...

Background: Recent increases in forest tree mortality should increase the abundance coarse woody detritus (CWD) and ultimately lead to increased atmospheric carbon dioxide. However, the time course of carbon release from CWD is not well understood. We compiled CWD decomposition rate-constants (i.e., k) to examine how tree species, piece diameter, position (i.e., standing versus downed), canopy openness, and macroclimate influenced k. To illustrate their implications we modeled the effect of species and position on estimates of decomposition-related carbon flux. We examined a subset of...

The Demonstration of Ecosystem Management Options (DEMO) Study is an operational-scale experiment in variable-retention harvests with six installations in western Washington and Oregon. Initiated in 1994, the experiment was designed to test key assumptions underlying standards and guidelines in the Northwest Forest Plan for regeneration harvests on matrix lands. The orthogonal portion of the six-treatment design (15 and 40 percent retention in both aggregated and dispersed patterns) is unique among large-scale variable-retention experiments, allowing for independent tests of responses to...

Resource managers are under increasing pressure to prioritize conservation efforts by assessing climate risk for numerous species. Amphibians, fish, and reptiles are particularly vulnerable to habitat alteration and climate change, yet many species fly under the conservation radar due to lack of basic information.Dede Olson, a research ecologist with the Pacific Northwest Research Station, has forged science partnerships among researchers from diverse disciplines that are yielding rapid advances in species threat assessments.Olson and three U.S. Geological Survey scientists developed an...

Novel outbreaks of emerging pathogens require rapid responses to enable successful mitigation. We simulated a 1-day emergency meeting where experts were engaged to recommend mitigation strategies for a new outbreak of the amphibian fungal pathogen Batrachochytrium salamandrivorans. Despite the inevitable uncertainty, experts suggested and discussed several possible strategies. However, their recommendations were undermined by imperfect initial definitions of the objectives and scope of management. This problem is likely to arise in most real-world emergency situations. The exercise thus...

Insects and pathogens are widely recognized as contributing to increased tree vulnerability to the projected future increasing frequency of hot and dry conditions, but the role of parasitic plants is poorly understood even though they are common throughout temperate coniferous forests in the western United States. We investigated the influence of western hemlock dwarf mistletoe (Arceuthobium tsugense) on large (≥45.7 cm diameter) western hemlock (Tsuga heterophylla) growth and mortality in a 500 year old coniferous forest at the Wind River Experimental Forest, Washington State, United...