Treesearch

National forest inventories have a long history of using remotely sensed auxiliary information to enhance estimation of forest parameters. For this purpose, aerial photography and satellite spectral data have been shown to be effective as sources of information in support of stratified estimators. These spectral-based stratifications are much more effective for reducing variances for forest area-related parameters than for parameters related to continuous attributes such as volume and biomass. For variables related to the latter attributes, stratified estimators using airborne laser...

Background: Carbon accounting in forests remains a large area of uncertainty in the global carbon cycle. Forest aboveground biomass is therefore an attribute of great interest for the forest management community, but the accuracy of aboveground biomass maps depends on the accuracy of the underlying field estimates used to calibrate models. These field estimates depend on the application of allometric models, which often have unknown and unreported uncertainties outside of the size class or environment in which they were developed. Results: Here, we test three popular allometric approaches...

Some federal public lands have been legally protected as “wilderness areas” since 1964 in the US. A federal science program evolved first in response to a novel public lands management concept, and subsequently in response to new issues that emerged both as society changed and more knowledge about social and ecological values of wilderness accumulated. Wilderness science needs have largely been defined by government and cooperating academic scientists through identification of researchable questions which, historically, have centered on science disciplines, wilderness attributes, or...

Sawmills are an important component of the hardwood industry, developing value-added products derived from the timber resources of the eastern United States. Employment in eastern sawmills has declined during the 21st century, reaching its lowest point in 2009 and 2010. Employment declines in the North and South Central regions of the United States were less than declines in the Northeast and Southeast regions, but East-wide employment was over 30 percent lower in 2010 than in 2001. The number of sawmills also has declined in the East, but since 2010, average employment in those mills has...

Acacia koa trees are ecologically, economically, and culturally significant to the Hawaiian Islands. Koa wood is one of the most valuable species in the world and sale of koa products represents a majority of all the Hawaiian wood products sold by Hawaiian retailers. Today, there is concern in Hawaii among foresters, forest landowners and managers, wood products manufacturers, and the public that the remaining old-growth koa resource has become scarce, is suffering from declining health and diseases, and is characterized by poor growth form. Current practices require harvest of only dead...

The majority of ecological studies in the tropics deal with organisms participating in grazing food webs, while few deal with the diversity of invertebrates in the soil, leaf litter or dead wood that participate in detrital food webs. For tropical forests, the status of information on soil animal diversity is limited, especially when compared to other ecosystems such as temperate forests, grasslands, and deserts. Given the high rate of forest conversion and persistence of deforestation in the tropics, it is important to study the diversity of its fauna and assess how global changes will...

Cross-laminated timber (CLT) is an emerging product in the North American mass timber market. Intended to compete with pre-cast concrete panels for modular construction, these laminated wall and floor-sized panels have been successfully used in European construction markets for the past 20 years. However, introduction of this material to areas of North America that have high pressure from subterranean termite and decay fungi may prove detrimental to the potential market for this product. This paper describes ongoing work seeking to describe interactions between CLT with both native and...

Dormancy strategies, including diapause and quiescence, enable insects to evade adverse conditions and ensure seasonally appropriate life stages. A mechanistic understanding of a species’ dormancy is necessary to predict population response in a changing climate. Climate change is influencing distribution patterns and population success of many species, including Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae: Scolytinae), the most important mortality agent of pines in western North America. Diapause is considered absent in D. ponderosae, and quiescence in the final larval...

Genome evolution is predicted to be rapid following the establishment of new (neo) sex chromosomes, but it is not known if neo-sex chromosome evolution plays an important role in speciation. Here we combine extensive crossing experiments with population and functional genomic data to examine neo-XY chromosome evolution and incipient speciation in the mountain pine beetle. We find a broad continuum of intrinsic incompatibilities in hybrid males that increase in strength with geographic distance between reproductively isolated populations. This striking progression of reproductive isolation...

Chromosomal rearrangement can be an important mechanism driving population differentiation and incipient speciation. In the mountain pine beetle (MPB, Dendroctonus ponderosae), deletions on the Y chromosome that are polymorphic among populations are associated with reproductive incompatibility. Here, we used RAD sequencing across the entire MPB range in western North America to reveal the extent of the phylogeographic differences between Y haplotypes compared to autosomal and X-linked loci. Clustering and geneflow analyses revealed three distinct Y haplogroups geographically positioned...