Treesearch

Increasing hardwood growing stock volume in the eastern United States from the 1950s to the 1990s was led by increases in poletimber volume. In the current century, volumetric growth has become concentrated in larger trees at least 17 in. dbh (≥17 in.). In the Central Hardwood region, the volume of such trees now exceeds poletimber volume by 75%. In this paper, we examine proportional and cubic volume increases of trees ≥17 in. across major species groups in the Central Hardwood region. In 2012, at least 40% of the volume of select white and red oaks, other red oaks, and yellow-poplar was...

The dihydroxyacetophenones 2,5-dihydroxyacetophenone (2,5-DHAP) and 2,6-dihydroxyacetophenone (2,6-DHAP) belong to the key chromophores in cellulosic materials. The pulp and paper industry targets these key chromophores in their bleaching sequences to obtain brighter products. 2,5- DHAP and 2,6-DHAP were degraded with hydrogen peroxide in alkaline media, similar to conditions of peroxide bleaching (P stage) in industrial pulp bleaching. Degradation product analyses were performed by GC–MS and NMR. The degradation reaction starts by loss of acetic acid originating from the acetyl moiety of...

5,8-Dihydroxy-[1,4]-naphthoquinone (DHNQ) is one of the key chromophores occurring in all types of aged cellulosics. This study investigates the degradation of DHNQ by chlorine dioxide at moderately acidic (pH 3) conditions, corresponding to the conditions of industrial bleaching (‘‘D stage’’). The degradation involves three major pathways. As initial reaction, a hydrogen transfer from DHNQ to chlorine dioxide via a PCET mechanism occurs to form a radical DHNQ and chlorous acid. DHNQ is then attacked by water to give a pentahydroxynaphthalene radical PHN that is stabilized by strong...

One of the challenges in the restoration of degraded lands is the re-establishment of soil structure and fertility. Novel forests that regenerate on recently abandoned and degraded agricultural lands are among the first biotic systems that begin the process of soil rehabilitation. The rate of litter decomposition and associated element mobility is one of many processes that contribute to the understanding of how ecosystem-level processes restore eroded soils. We studied the stoichiometry of Spathodea campanulata leaves decomposing in novel subtropical moist forests. We found that the speed...

The decrease in sawn hardwood consumption continues in the UNECE region in 2017, dropping by 3.2% to 34.4 million m3, the lowest value in the last four years. Sawn hardwood production in the UNECE region was relatively flat, at 41.7 million m3, with slight or no increases in Europe and North America and a rise in the CIS. Global demand for hardwood remained strong in 2017, enabling sawn hardwood producers to ship record volumes to markets outside the UNECE region, mainly China. Sawn hardwood exports in the UNECE region reached an all-time high in 2017, increasing by 9.6% to 13.7 million...

Changes in land systems generate many sustainability challenges. Identifying more sustainable land-use alternatives requires solid theoretical foundations on the causes of land-use/cover changes. Land system science is a maturing field that has produced a wealth of methodological innovations and empirical observations on landcover and land-use change, from patterns and processes to causes. We take stock of this knowledge by reviewing and synthesizing the theories that explain the causal mechanisms of land-use change, including systemic linkages between distant land-use changes, with a...

Shortleaf pine (Pinus echinata Mill.) is the most widely distributed and poorly understood of the four major species of southern yellow pine. The area of southern forests dominated by shortleaf pine forest types has declined by more than 50 percent since 1980, with the most dramatic declines found in states east of the Mississippi River. To counteract this decline, the Shortleaf Pine Initiative was launched in the spring of 2013 by a host of partners including the U.S. Department of Agriculture Forest Service, other Federal and State agencies, universities, major conservation organizations,...

Natural disturbance events, such as ice storms, may last from hours to a few days, but their impacts may create long-term disturbance in forest structure and development (Bragg 2016, Turcotte and others 2012). Following ice storms, the development and survival of individual trees may be affected by numerous factors such as extent of damage, residual density, stand age, vigor, site condition, and species (Bragg and others 2003, Dipesh and others 2015, Saud and others 2016a). In the Southwestern United States, pine species experience considerable crown damage from ice storms since they...

In 2009, the America’s Longleaf Restoration Initiative set an aggressive goal of increasing the area of ecosystems dominated by longleaf pine (Pinus palustris) from 4.29 to 8 million acres by 2025. In 2015, a 5-year review of progress using Forest Inventory and Analysis data showed that gains in longleaf pine acreage were offset by losses and that total longleaf pine acreage remained unchanged since 2010. As a result, Federal, State, and private partners engaged in a review during the summer of 2016 to discuss how to modify or respond to this lack of progress; they agreed to retain the...

Using tracked processors over knuckle–boom loaders to increase total value per tree when merchandizing timber on the landing has become a topic of interest in the southeastern region of the United States. This study compared merchantability values, product classes, and product weights of loblolly pine (Pinus taeda) for both machines to determine if there was a significant difference between machines when processing the same tree. In order to process the same tree twice, the chains from the tracked processor had to be removed from the bottom saw bar. This allowed the processor to simulate...