Treesearch

Over the past decade, the use of wood for thermal energy in Alaska has grown significantly. Since 2000, nearly 30 new thermal wood-energy installations in Alaska have been established. Cordwood units, burning primarily firewood and other forms of roundwood, have played an integral part in this success and are well suited to many rural communities in Alaska. In this case study, we evaluate cordwood installations located in three geographic regions of Alaska. Included are systems at Coffman Cove (southeast Alaska), Ionia (Kenai Peninsula, Alaska), and Gulkana (south-central Alaska). We...

Sitka, Alaska, has substantial hydroelectric resources, limited driving distances, and a conservation-minded community, all suggesting strong opportunities for achieving a low community carbon footprint. In this research we evaluate the level of carbon dioxide (CO2) emissions from Sitka and compare this to the estimated CO2 sequestration potential of forest ecosystems. We determine whether a carbonneutral community is attained when these two factors are balanced. Our analysis consisted of two parts: estimating anthropogenic CO2 emissions from Sitka, and comparing this value to estimates of...

New research reveals how topography, soil temperature, and subtle shifts in soil drainage are key drivers in ecosystem function in the coastal temperate rain forests of southeast Alaska and British Columbia. These studies, by Dave D'Amore and his colleagues, provide a better understanding of the influence of soil hydrology on dissolved organic carbon export and the interplay between soil saturation and tree species' response to varying soil conditions. More refined techniques for identifying hydric soils are making wetland delineation in southeast Alaska quicker, easier, and more accurate....

The impact of mutualists on a partner’s demography depends on how they affect the partner’s multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and simulations of long-term population dynamics to quantify the demographic impact of a guild of ant species on the plant Ferocactus wislizeni. The ants feed at the plant’s extrafloral nectaries and attack herbivores attempting to...

It is well known that the timing of growth and development influences critical life stages of all organisms. „The seasonal dynamics of ecosystems are usually well explained by photoperiod and temperature. However, phenological patterns in water-limited ecosystems are rarely studied and insufficiently explained by these two variables. We tested how onset (i.e., initiation of plant growth) and seasonality of plant growth are in‰fluenced by soil temperature and soil water. We collected seven years of daily measurements of near- surface re‰flected radiation, soil moisture, and soil temperature...

Piscivory by birds can be important, particularly on fish in small streams and during seasonal low flows when available cover from predators can be limited. We conducted an experiment at the Oregon Hatchery Research Center to evaluate size-selective survival of Coastal Cutthroat Trout (Figure 8; Oncorhynchus clarkii clarkii) in replicated semi-natural stream sections. Our findings, published in the Ecology of Freshwater Fish highlights that availability of instream cover and overhead shade from riparian vegetation can increase trout survival by reducing the effect of predation by Belted...

Accuracy assessments of remote sensing products are necessary for identifying map strengths and weaknesses in scientific and management applications. However, not all accuracy assessments are created equal. Motivated by a recent study published in Forest Ecology and Management (Volume 342, pages 8–20), we explored the potential limitations of accuracy assessments related to characteristics of the field data: sampling bias and spatial resolution. The authors of the previous paper used data from variable radius plots near northern spotted owl nest sites to assess the predictive accuracy of...

Contributing to the worldwide biodiversity crisis are emerging infectious diseases, which can lead to extirpations and extinctions of hosts. For example, the infectious fungal pathogen Batrachochytrium dendrobatidis (Bd) is associated with worldwide amphibian population declines and extinctions. Sensitivity to Bd varies with species, season, and life stage. However, there is little information on whether sensitivity to Bd differs among populations, which is essential for understanding Bd-infection dynamics and for formulating conservation strategies.We experimentally investigated intraspeci...

Communicating the scientific knowledge generated by the Pacific Northwest Research Station is integral to our mission. The 2014 Science Accomplishments reports highlights the breadth of the station’s research, the relevance of our science findings, and the application of these findings. The photographs throughout the report showcase the region where we work and how science is done.

The scientific and policy literature on climate change increasingly recognizes the vulnerabilities of indigenous communities and their capacities for resilience. The role of gender in defining how indigenous peoples experience climate change in the United States is a research area that deserves more attention. Advancing climate change threatens the continuance of many indigenous cultural systems that are based on reciprocal relationships with local plants, animals, and ecosystems. These reciprocal relationships, and the responsibilities associated with them, are gendered in many indigenous...