Treesearch

A Particle-Into-Liquid Sampler - Total Organic Carbon (PILS-TOC) and fraction collector system was flown aboard a Twin Otter aircraft sampling prescribed burning emissions in South Carolina in November 2011 to obtain smoke marker measurements. The fraction collector provided 2 min time-integrated offline samples for carbohydrate (i.e., smoke markers levoglucosan, mannosan, and galactosan) analysis by high-performance anion-exchange chromatography with pulsed amperometric detection. Each fire location appeared to have a unique 1levoglucosan /1water-soluble organic carbon (WSOC) ratio...

Questions: Do successional trajectories in plant diversity, heterogeneity and dominance respond differently to ungulate exclusion in unmanaged forests vs managed forests that are thinned and burned? Is vegetation in recently thinned and burned standsmore sensitive to changes in the grazing regime? Location: Northeast OR, USA. Methods: We evaluated changes in plant community composition, diversity, heterogeneity and dominance under herbivory by multiple ungulates (cattle, elk, deer) vs ungulate exclusion at sites where trees were recently thinned and a prescribed burn was applied (managed),...

Field and greenhouse studies examined the effects of growth habit and chloroplast presence in leaf veins for their role in increasing agronomic water use efficiency and yields of California modern processing tomato (Solanum lycopersicum L.) cultivars. Five introgression lines (ILs), made with Solanum pennellii Cor. in the genetic background of cultivar M82, differ in genes that map to a region on Chromosome 5, including the SP5G gene (determinate vs. semideterminate (Det vs. SemiDet)) and the obv gene (presence (obscure) vs. absence (clear) of leaf vein chloroplasts (Obs vs. Clr)). The...

Arsenic (As) contamination of soils and water is a global problem because of its impacts on ecosystems and human health. Various approaches have been attempted for As remediation, with limited success. Arbuscular mycorrhizal (AM) fungi play vital roles in the uptake of water and essential nutrients, especially phosphorus (P), and hence enhance plant performance and productivity (Smith and Read 2008). As uptake and tolerance to As toxicity in plants are also enhanced by AM fungi (Zhao et al. 2009; Smith et al. 2010; Gonzalez-Chavez et al. 2011). The use of AM fungi has thus been proposed as...

Comparative and evolutionary genomic approaches can identify genes regulating biological processes, and describe how those genes have been modified through speciation to produce phenotypic variation. These approaches have the potential to address fundamental issues of forest biology, including the regulation of biological traits important to industry and conservation, but have not been widely applied because of technical limitations. Here, we argue that powerful "next generation" DNA sequencing technologies now make comparative and evolutionary genomic approaches not only tractable for...

The relationships of mycorrhizal fungal respiration and productivity to climate and atmospheric chemistry remain under characterized. We quantified mycorrhizal sporocarp and hyphal respiration, as well as growing season net hyphal production, under ambient and elevated carbon dioxide (CO2) and ozone (O3) in relation to natural temperature and moisture variation. Hyphal respiration did not respond significantly to elevated CO2 and O3. Sporocarp respiration was affected by temperature and moisture content while hyphal respiratory response to temperature was undetected over the narrower range...

Invasive Species Science Updates are designed to keep managers and other users up-to-date with recently completed and ongoing research by RMRS scientists, as well as highlight breaking news related to invasive species issues. The newsletter is produced by the RMRS Invasive Species Working Group (ISWG), which is a core group of scientists who volunteer to coordinate outreach of RMRS invasive species science to managers and the public through this newsletter, our website, and periodic white papers. In this and future issues of the newsletter we want to continue to recognize partnerships and...

With the translocation and release of 90 fishers [Pekania pennanti (formerly Martes pennanti)] from British Columbia to Olympic National Park during 2008-2010, the National Park Service and Washington Department of Fish and Wildlife accomplished the first phase of fisher restoration in Washington State. Beginning in 2013, we initiated a new research project to determine the current status of fishers on Washington’s Olympic Peninsula 3-5 years after the releases and evaluate the short-term success of the restoration program. Objectives of the study are to determine the current distribution...

Post-fire sediment yields can be up to three orders of magnitude greater than sediment yields in unburned forests. Much of the research on post-fire erosion rates has been at small scales (100m2 or less), and post-fire sediment delivery rates across spatial scales have not been quantified in detail. We developed relationships for post-fire bedload sediment delivery rates for spatial scales up to 117 ha using sediment yield data from six published studies and two recently established study sites. Sediment yields and sediment delivery ratios (SDRs; sediment delivered at the catchment scale...