Treesearch

The complex interactions among the genes that underlie a biological process can be modeled and presented as a transcriptional network, in which genes (nodes) and their interactions (edges) are shown in a graphical form similar to a wiring diagram. A large number of genes have been identified that are expressed during the radial woody growth of tree stems (secondary growth), but a comprehensive understanding of how these genes interact to influence woody growth is currently lacking. Modeling transcriptional networks has recently been made tractable by next-generation sequencingbased...

Disk refining and ultrasonication treated sugarcane bagasse residues reclaimed from the waste stream of a simplified bioethanol process after fermentation were used to fabricate biobased composites with poly(vinyl alcohol) (PVA) by film casting. The morphologies and the size distributions of residue particles were characterized by scanning electronic microscopy and various particle size analyzers. The results showed that the residue particle sizes were about hundreds nanometers to tens microns after disk refining treatment. After further treatment by ultrasonication, the particle sizes...

The annual rate of population change (λt) is a good metric for evaluating population performance because it summarizes survival and recruitment rates and can be used for open populations. Another measure of population performance, realized population change (Δt) is an encompassing metric of population trend over a period of time; it is the ratio of population size at an end time period relative to the initial population size. Our first goal was to compare mean λ and Δt as summaries of population change over time. Our second goal was to evaluate different methods for estimating these...

After identifying 114 microsatellite loci from Choristoneura fumiferana expressed sequence tags, 87 loci were assayed in a panel of 11 wild-caught individuals, giving 29 polymorphic loci. Further analysis of 20 of these loci on 31 individuals collected from a single population in northern Minnesota identified 14 in Hardy-Weinberg equilibrium.

Entries qualify for inclusion if they were conducted in whole or part at the Desert Experimental Range (DER, also known as the Desert Range Experiment Station) or were based on DER research in whole or part. They do not qualify merely by the author having worked at the DER when the research was performed or prepared. Entries were drawn from the original abstracts or summaries when those were included in the original document. The conclusions are those of the original authors. Likewise, (1) taxonomic treatments are those of the original authors with our occasional annotations for clarificati...

A project was initiated in 2003 to establish test sites to develop methods to reintroduce the American elm (Ulmus americana L.) in forested landscapes. American elm tree strains with high levels of tolerance to Dutch elm disease (DED) were established in areas where the trees can naturally regenerate and spread. The process of regeneration will allow the American elm to co-evolve with the DED fungal pathogen to ensure this valuable tree species will not be lost from the landscape. This effort in Ohio is being carried out in partnership with the Ohio Department of Natural Resources-Division...

The mountain pine beetle has killed lodgepole pine and other species of pines in the western United States in an ongoing epidemic. The most heavily affected states are in the interior West: Colorado, Idaho, Montana, and Wyoming, with smaller losses elsewhere. Timber salvage is one response to the epidemic, which could generate revenues for affected landowners and provide wood to forest product manufacturers and, potentially, energy producers. Salvage is occurring, but policymakers have advocated greater rates of such timber removals. To estimate total costs and revenues from salvage and...

The objective of this research was to evaluate soil subsurface methods that may aid in seedling establishment and encourage root colonization from a diverse group of ectomycorrhizal (ECM) fungi during restoration projects. American chestnut Castanea dentata Marsh. Borkh. and backcrossed chestnuts seedlings were planted on a reclaimed coal mine site in central Ohio, USA. Roots from chestnut seedlings planted in the plots that were cross-ripped, plowed and disked, or a combination of treatments were sampled for ECM fungi and compared with control plots. The presence and identification of...

Coarse woody debris (CWD; defined here as fallen and standing dead trees and tree ferns) is a critical structural and functional component of forest ecosystems that typically comprises a large proportion of total aboveground carbon (C) storage. However, CWD estimates for the tropics are uncommon, and little is known about how C storage in CWD will respond to climate change. Given the predominant role that tropical forests play in global C cycling, this information gap compromises efforts to forecast climate change impacts on terrestrial C balance. The primary objectives of this study were...

The structure of a forest canopy is the key determinant of light transmission, use and understory availability. Airborne light detection and ranging (LiDAR) has been used successfully to measure multiple canopy structural properties, thereby greatly reducing the fieldwork required to map spatial variation in structure. However, lidar metrics to date do not reflect the full extent of the three-dimensional information available from the data. To this end, we developed a new metric, the polar grid fraction (GRID), based on gridding lidar returns in polar coordinates, in order to more closely...