Treesearch

Tropical Iiana abundance has been increasing over the past 40 yr, which has been associated with reduced rainfall. The proposed mechanism allowing lianas to thrive in dry conditions is deeper root systems than co-occurring trees, although we know very little about the fundamental hydraulic physiology of lianas. To test the hypothesis that two abundant Iiana species would physiologically outperform their host tree under reduced water availability, we measured rooting depth, hydraulic properties, plant water status, and leaf gas exchange during the dry season in a seasonally dry tropical...

Tree shelters can aid hardwood seedling establishment by improving early seedling survival and growth. This study was established in Arkansas to compare three types of tree shelters installed on green ash (Fraxinus pennsylvanica Marsh.) and cherrybark oak (Quercus pagoda Raf.) seedlings. Seedlings planted in 4 feet tall Blue-X®, Protex® or Tubex® tree shelters were compared to unsheltered controls with respect to survival, browse damage, emergence, groundline diameter, and height. Tubex® shelters cost about twice as much to purchase and establish as the Blue-X® shelters, with the Protex®...

Appropriate forest management decisions for the developing woody biofuel and carbon credit markets require inventory and growth-and-yield systems reporting component tree dry weight biomass estimates. We have developed an integrated growth-and-yield and biomass/carbon calculator. The objective was to provide Mississippi’s State inventory system with bioenergy economic development tools and forest landowners trying to qualify for carbon credit programs with carbon estimates. Biomass equations were collected from many sources in the literature and organized into a uniform software system...

This paper reports on a long-term thinning study established in stands of naturally seeded loblolly (Pinus taeda L.) and shortleaf (P. echinata Mill.) pine in southern Arkansas and northern Louisiana. Plots were established in 1949–50 and 1954 in previously unmanaged stands, thinned about once every 5 years from age 20 to 60 years (40 years of active cutting, to 1990). The study was discontinued in 1995 when the stands were about 65 years old. Low-density stands on good sites produced bigger individual pines more quickly than denser stands on medium sites. Long-term sawtimber yields did...

Clonal forestry offers the opportunity to increase yields, enhance uniformity, and improve wood characteristics. Intensive silvicultural practices, including fertilization, will be required to capture the full growth potential of clonal plantations. However, variation in nutrient use efficiency that exists among clones could affect growth responses. Our research objective was to determine the range of growth response and stem form quality due to fertilization in clones of Pinus taeda. A split-plot experimental design was used, with the whole plots being 2 levels of fertilization (with or...

Species composition within ecological assemblages can drive disease dynamics including pathogen invasion, spread, and persistence. In multi-host pathogen systems, interspecific variation in responses to infection creates important context dependency when predicting the outcome of disease. Here, we examine the responses of three sympatric host species to a single fungal pathogen, Batrachochytrium dendrobatidis, which is associated with worldwide amphibian population declines and extinctions. Using an experimental approach, we show that amphibian species from three different genera display...

A study was undertaken at the United States Department of Energy's Savannah River Site (SRS), Aiken, South Carolina to investigate radionuclide activity concentrations in litter and duff from select areas at SRS. Litter (i.e., vegetative debris) and duff (i.e., highly decomposed vegetative debris) can often be the major fuels consumed during prescribed burns and have potential to release radiological contaminants into the environment. Repeated samples from 97 locations were collected systematically across SRS and analyzed for radionuclide activity. Radionuclide activity concentrations...

The principle findings of the ninth forest survey of Alabama (2010) and changes that have occurred since the previous surveys are presented. Topics examined include forest area, ownership, forest-type groups, stand structure, basal area, timber volume, growth removals, and mortality. Alabama’s contribution to the Nation’s forest resources and regional comparisons are detailed.

These early surveys were not concerned with the forests, species, and tree sizes that were not considered commercially viable. Early surveys reported only on growing-stock trees on timberlands, i.e. commercially important tree species and tree sizes on forests that could sustain harvest operations. Currently, FIA reports on all of the forest lands regardless of site productivity or the potential to provide forest products. This science update will focus on long-term trends using the traditional measures of growing stock and timberland. A more detailed analysis focusing on all forest lands,...

This science update summarizes the findings of the statewide annual inventory of the forest resource attributes in Oklahoma conducted by the Southern Forest Inventory and Analysis (FIA) program in cooperation with the Oklahoma Forestry Services. The 77 counties of Oklahoma are consolidated into seven FIA survey units— southeast (unit 1), northeast (unit 2), north central (unit 3), south central (unit 4), southwest central (unit 5), high plains (unit 6), and great plains (unit 7). East Oklahoma is made up of units 1 and 2, while central and west Oklahoma consist of units 3 thru 7 (fig. 1)....