Treesearch

Tree encroachment threatens the biodiversity and ecological functioning of grasslands worldwide. Reversing effects of encroachment requires not only removing trees, but limiting subsequent invasions, which can stall grassland reassembly. We quantified rates and patterns of conifer reinvasion of mountain grasslands (meadows) in western Oregon, 7 and 15 years after experimental tree removal with or without burning. We assessed frequency (percentage of 100 m2 subplots) and density of reinvading trees in six 1-ha plots as a function of burn treatment, abundance in the adjacent forest (a proxy...

Food webs show the architecture of trophic relationships, revealing the biodiversity and species interactions in an ecosystem. Understanding which factors modulate the structure of food webs offers us the ability to predict how they will change when influential factors are altered. To date, most of the research about food webs has focused on species interactions whereas the influences of surrounding environments have been overlooked. Here, using network analysis, we identified how the structure of aquatic food webs varied across a range of geophysical conditions within a whole stream...

The influences of inter- and intraspecific variation in leaf litter quality on aquatic food webs are well understood. However, the timing and type of organic matter inputs also varies within a species based on plant phenophase, including litterfall and flowering, which may influence instream communities and ecosystem processes including decomposition. We investigated how leaf and flower litters of a willow shrub species (Salix sitchensis) influenced decomposition and aquatic invertebrate colonization in a headwater stream. We collected abscised willow catkins and leaves from female plants,...

Between 1989 and 2012, three Forest Service programs collected more than 8,300 surveys of epiphytic lichen communities, providing a baseline for tracking lichen responses to air quality, climate, and other changes on forest land in the United States. This national atlas of lichen species combines these datasets into distribution maps for more than 400 taxa and 6,000 forested locations across the country. All 115,500 lichen records presented in the maps link to voucher specimens, most of which can be accessed from herbaria. Unlike mapped herbarium records, most surveys were collected on a...

A description of major biotic and abiotic features within the North Fork Hunter Creek and Hunter Creek Bog areas of critical environmental concern in southwestern Oregon. Extensive lists of vascular plants, fungi, lichens, bryophytes, and wildlife species known or likely to occur are provided in appendices. This guidebook is part of a continuing series of guidebooks on federal research natural areas that began in 1972.

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...

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.

This resource bulletin is part of a series of reports presenting findings from a University of Montana Bureau of Business and Economic Research (BBER) census of Alaska’s primary forest products industry. Part 1 of this series presents information on the volume of timber harvested in Alaska during 2015 by product, ownership, species, and resource area. It also describes the flow of timber within the state, across state lines, and exports to countries outside the United States.