Treesearch

Protoplast isolation and subsequent plant regeneration of Albizia julibrissin was achieved from leaf and callus explants. Leaf tissue from 4 to 5-week-old in vitro seedlings was the best source for high-yield protoplast isolation. This approach produced 7.77 × 105 protoplasts (Pp) per gram fresh weight with 94 % viability; after 60 min pre-plasmolysis with 0.7 M sorbitol followed by digestion in a solution of cell and protoplast wash plus 0.7 M mannitol, 1.5 % cellulase Onozuka R10, and 1 % pectolyase Y-23 for 6 h. Liquid Kao and Michayluk medium containing 2.7 μM α-naphthaleneacetic acid...

An emerging hypothesis in fire ecology is that pyrodiversity increases species diversity.We test whether pyrodiversity—defined as the standard deviation of fire severity—increases avian biodiversity at two spatial scales, and whether and how this relationship may change in the decade following fire. We use a dynamic Bayesian community model applied to a multi-year dataset of bird surveys at 1106 points sampled across 97 fires in montane California. Our results provide strong support for a positive relationship between pyrodiversity and bird diversity. This relationship interacts with time...

growing body of literature examines the vulnerability, risk, resilience, and adaptation of indigenous peoples to climate change. This synthesis of literature brings together research pertaining to the impacts of climate change on sovereignty, culture, health, and economies that are currently being experienced by Alaska Native and American Indian tribes and other indigenous communities in the United States. The knowledge and science of how climate change impacts are affecting indigenous peoples contributes to the development of policies, plans, and programs for adapting to climate change...

Healthy Rivers Connect Humans and Ecosystems James Nash says he is part trout. Growing up on a ranch in the Wallowa Valley of northeast Oregon, he disappeared as often as he could to the banks of the Wallowa River, which runs for more than two miles through his family’s land. Once, while exploring the bottomland, he discovered some old ruts and grooves in the ground. “At first I didn’t know what they were,” he said. “But even as an 8-year-old, I could tell those channels would be better fishing.” He had found an old natural channel of the Wallowa River.

This article presents the design optimization of an un-notched Iosipescu test specimen whose goal is the characterization of the material elastic stiffnesses of a Loblolly (Pinus taeda) or Lodgepole pine (Pinus contorta) sample in one single test. A series of finite element (FE) and grid simulations were conducted to determine displacement and strain fields for various ring angles, ring spaces, and proportions of latewood per ring. These displacement and strain fields were utilized to determine the constitutive parameters for the woody material using VFM. Using an error function based on a...

Plant tissue δ15N is frequently used as a proxy for N availability and N cycle dynamics, and the δ15N signature of tree rings could potentially be used to reconstruct past changes in the N cycle due to forest disturbance or anthropogenic N deposition. However, there are substantial uncertainties regarding how effectively tree ring δ15N records N cycle dynamics. We used increment tree cores from a forested watershed that received a one-time application of urea, along with the long-term stream water chemistry record from that watershed and a nearby reference watershed, to determine the...

Manchurian walnut (Juglans mandshurica Maxim.) is a vulnerable, temperate deciduous tree valued for its wood and nut, but transcriptomic and genomic data for the species are very limited. Next generation sequencing (NGS) has made it possible to develop molecular markers for this species rapidly and efficiently. Our goal is to use transcriptome information from RNA-Seq to understand development in J. mandshurica and develop polymorphic simple sequence repeats (SSRs, microsatellites) to understand the species' population genetics. In this study, more than 47.7 million clean reads were...

We describe the historical and current distribution of tree voles (Arborimus longicaudus; A. pomo) and compare the minimum density of trees with tree vole nests in different forest age-classes based on museum records, field notes of previous collectors, tree vole nest surveys conducted by federal agencies, and our field studies in Oregon and California. We conclude that tree voles are still fairly common in old forests within much of their historical range, but have become uncommon or rare in some areas as a result of fire and logging. Our analysis of food stored at red tree vole (A....

High-intensity wildfires are one of the leading causes of severe soil erosion in western U.S. watersheds. This erosion can lead to disruptive deposits of sediment in reservoirs and water supply systems. Fuel treatments such as controlled burns and forest thinning can reduce wildfire intensity and help preserve topsoil. But while these treatments are generally much less expensive than firefighting, property loss, and sediment removal, there are limited funds available for controlled burns and forest thinning. For this reason, land managers can benefit from estimating the erosion potential...

Maps of the number, size, and species of trees in forests across the western United States are desirable for many applications such as estimating terrestrial carbon resources, predicting tree mortality following wildfires, and for forest inventory. However, detailed mapping of trees for large areas is not feasible with current technologies, but statistical methods for matching the forest plot data with biophysical characteristics of the landscape offer a practical means to populate landscapes with a limited set of forest plot inventory data. We used a modified random forests approach with...