Treesearch

Nutritional bacterial symbionts enhance the diets of sap-feeding insects with amino acids and vitamins missing from their diets. In many lineages, an ancestral senior symbiont is joined by a younger junior symbiont. To date, an emergent pattern is that senior symbionts supply a majority of amino acids, and junior symbionts supply a minority. Similar to other hemipterans, adelgids harbor obligate symbionts, but have higher diversity of bacterial associates, suggesting a history of symbiont turnover. The metabolic roles of dual symbionts in adelgids and their contributions to the consortium...

We compared crayfish collections from minnow versus microhabitat traps in the Dahomey National Wildlife Refuge, Bolivar County, Mississippi, USA, extending the knowledge of microhabitat trap effectiveness to seasonal bottomland hardwood forest floodplains. Crayfishes were captured in three seasonally flooded habitat types: wooded, trail, and open habitats. The CPUE of vernal crayfish Procambarus viaeviridis and White River crayfish P. acutus was higher in minnow traps, whereas CPUE of swamp dwarf crayfish Cambarellus puer was higher in microhabitat traps. The CPUE did not differ among...

State forest enterprises (SFEs) in Vietnam for decades were the main source of industrial wood production, but smallholder forest plantations have become common. Smallholders need positive financial returns to be viable. Likewise, financial returns are an important consideration of proposals to turn SFEs into joint ventures, because the potentially involved private companies would seek reasonable returns on investment. Financial analyses of smallholder and SFE forest plantations were undertaken to evaluate their competitiveness and profitability, and to assess opportunities and challenges...

This report highlights key findings from a test (“pilot”) of an interior Alaska forest inventory design. The pilot inventoried the forests of the Tanana Valley State Forest (TVSF) and the Tetlin National Wildlife Refuge (TNWR) in the Tanana River Valley of interior Alaska, covering 2.5 million ac. The inventory consisted of a systematic grid of 98 field-measured plots integrated with NASA’s Goddard- LiDAR/Hyperspectral/Thermal (G-LiHT) imaging system. We summarize and interpret basic resource information such as forest area, ownership, volume, carbon stocks in trees, ground layers, dead...

The Black-backed Woodpecker (Picoides arcticus) is a snag-associated species that colonizes and utilizes patches of burned forests typically within 10 years of fire. Previous research has indicated that salvage logging, the removal of dead and dying trees from burned forests, has a negative effect on nesting densities of Black-backed Woodpeckers. One strategy proposed to ameliorate the impacts of dead tree removal on Black-backed Woodpeckers is to retain patches, or islands, of dense snags within the salvage matrix, but this approach remains largely untested. Following the Angora fire of...

Longleaf pine (Pinus palustris Mill.) forests are historically and ecologically important and also endangered ecosystems in the southeastern United States. In addition to extensive exploitation and land use conversion, one characteristic which contributed to their dramatic decline and presents a continuing challenge to their future recovery is the sporadic timing of their seed production. In this study, about 60 years of cone production data for longleaf pine forests at four different sites were quantitatively characterized from different perspectives. Results indicated that longleaf pine...

There is an increasing interest in estimating biomass for longleaf pine (Pinus palustris Mill.), an important tree species in the southeastern U.S. Most of the individual-tree allometric models available for the species are local, relying on stem diameter outside bark at breast height (DBH) and total tree height (HT), but seldom include stand-level variables such as stand age, basal area or stand density. Using the biomass dataset of 296 longleaf pine trees sampled in the southeastern U.S. by different forestry research institutions, we developed a set of local and general systems of tree...

For remote sensing-assisted natural resource inventories, the effects of spatial resolution in the form of pixel size and the effects of subpixel information on estimates of population parameters were evaluated by comparing results obtained using Landsat 8 and RapidEye auxiliary imagery. The study area was in Burkina Faso, and the response variable of interest was firewood volume (m3/ha). A sample consisting of 160 field plots was selected from the population following a two-stage sampling d0esign. Models were fit using weighted least squares; the population mean, μ, and the variance of...

Much of the North American wood products industry was severely impacted by the recession of 2008–2009. In addition, many sectors within this industry face intense global competition. Against this backdrop, we examine economic opportunities for hardwood manufacturers to achieve greater competitive advantage via product customization, through a literature review and synthesis. We also discuss several related themes including agility, lean manufacturing, and clustering. We found that, in globally competitive environments, hardwood producers must be agile to adapt to economic conditions and...

Because shrub cover is related to many forest ecosystem functions, it is one of the most relevant variables for describing these communities. Nevertheless, a harmonized indicator of shrub cover for large-scale reporting is lacking. The aims of the study were threefold: to define a shrub indicator that can be used by European countries for harmonized shrub cover estimation using data from their respective national forest inventories (NFIs); to quantify the effects of using different NFI field cover scales; and to establish bridges to facilitate harmonized estimation. Data for shrub species...