Treesearch

Dams and the reservoirs they create are notorious for disrupting the migration of salmon, both when they travel downstream as juveniles and when they return to spawn years later as adults. In an effort to improve downstream salmon migration, the U.S. Army Corps of Engineers in 2011 began yearly, short-term draining of Fall Creek Reservoir located on a tributary of the Willamette River in Oregon. The reservoir is drained down to the streambed over one week every autumn. The full effects of this novel practice were largely unknown until researchers Sherri Johnson and Christina Murphy...

Forests in the southwestern USA are well adapted to dry conditions. High lightning incidence, long human habitation, and frequently windy conditions make the Southwest stand out for a high pace of burning. Forests are structured by climatic gradients created by elevation and topography. Low-elevation woodlands experience the driest conditions, but low productivity limits fuels. At the other extreme, high-elevation forests produce abundant fuels but are rarely dry enough to burn. The "sweet spot" in the middle elevations, dominated by pines and other mixed conifers, is characterized by...

This resource bulletin is part of a series of reports presenting findings from a census of Alaska’s primary forest products industry. Part 2 of the series presents information on the forest products industry sectors that processed timber and mill residue into finished wood products in 2015. All dollar figures included have been adjusted for inflation to constant 2015 dollars, unless otherwise noted.

This resource bulletin is part of a series of reports presenting findings from a census of Alaska’s primary forest products industry. Part 3 of the series presents information on sales value and employment associated with primary wood products manufacturing, the economic contribution of forest products manufacturing in the state, and an analysis of the changes in the broader forest industry over time. All dollar figures included have been adjusted for inflation to constant 2015 dollars, unless otherwise noted.

This resource bulletin is part of a series of reports presenting findings from a census of Alaska’s primary forest products industry. Part 4 of the series presents data tables characterizing information on Alaska’s forest products industry sectors that processed timber and mill residue into finished wood products during 2015. Part 4 of this series includes those tables contained in parts 1 through 3 as well as supplemental tables characterizing additional information on Alaska’s forest products industry and timber harvest.

1. Carbon uptake by the terrestrial biosphere depends on supplies of new nitrogen (N) from symbiotic N fixation, but we lack a framework for scaling fixation accurately and for predicting its response to global change. 2. We scaled symbiotic N fixation from individual N fixers (i.e. plants that host N-fixing bacteria), by quantifying three key parameters—the abundance of N fixers, whether they are fixing N and their N fixation rates. We apply this framework to black locust, a widespread N-fixing tree in temperate forests of the eastern United States, and harness long-term data from...

Since the 1990s, functional diversity has attracted growing attention from biodiversity scientists. In recent years, various functional diversity indices have been proposed; but many of them presented conceptual and/or practical limitations. We recently developed a functional diversity index, Functional Extension and Evenness (FEE), to overcome some of the limitations. In this paper, we describe the content and major features of a new R package, FEEr, which serves as a tool for calculating the FEE index. The FEEr package includes one major core function to accomplish the FEE calculation...

Wood is a sustainable structural material, but it cannot be easily shaped while maintaining its mechanical properties. We report a processing strategy that uses cell wall engineering to shape flat sheets of hardwood into versatile three-dimensional (3D) structures. After breaking down wood’s lignin component and closing the vessels and fibers by evaporating water, we partially re-swell the wood in a rapid water-shock process that selectively opens the vessels. This forms a distinct wrinkled cell wall structure that allows the material to be folded and molded into desired shapes. The...

A growing body of community resilience literature emphasizes the importance of social resources in preparing for and responding to disturbances. In particular, scholars have noted that community based organizations and strong social networks positively contribute to adaptive capacity, or the ability to adjust and respond to change while enhancing the conditions necessary to withstand future events. While it is well established that strong civic engagement and social networks contribute to enhanced adaptive capacity in times of change, there is more to learn about how adaptive capacity at...

Climate warming is expected to accelerate peatland degradation and release rates of carbon dioxide (CO2) and methane (CH4). Spruce and Peatlands Responses Under Changing Environments is an ecosystem-scale climate manipulation experiment, designed to examine peatland ecosystem response to climate forcings. We examined whether heating up to +9 °C to 3 m-deep in a peat bog over a 7-year period led to higher C turnover and CO2 and CH4 emissions, by measuring 14C of solid peat, dissolved organic carbon (DOC), CH4, and dissolved CO2 (DIC). DOC, a major substrate for heterotrophic respiration,...