Treesearch

The role that genetic improvement plays in the increase of productivity in loblolly pine (Pinus taeda L.) in the South has been recognized (McKeand and others 2003). Varietal forestry has the potential to improve the productivity and quality of loblolly pine stands, and higher genetic gains can be achieved in volume and stand uniformity (Zobel and Talbert 1984).

We utilized 15-year measurements from an organic matter manipulation experiment in a loblolly pine plantation in the Upper Coastal Plain of Alabama to examine the apparent resiliency of a loblolly pine stand to organic matter removal. Treatments included complete removal of harvest residues and forest floor (removed), doubling of harvest residues and forest floor (added), and a standard harvest residue management (reference). Mineral soil and O horizons were sampled and analyzed for carbon (C) and nitrogen (N) using dry combustion. The δ15N and CuO oxidation biomarkers were assessed in...

Dependence on foreign oil continues to increase, and concern over rising atmospheric CO2 and other greenhouse gases has intensified research into sustainable biofuel production. Intercropping switchgrass (Panicum virgatum L.) between planted rows of loblolly pine (Pinus taeda L.) offers an opportunity to utilize inter-row space that typically contains herbaceous and weedy competition for the production of a biomass feedstock.

A longleaf pine (Pinus palustris Mill.) field performance study was established in central Louisiana in 2004. The study has received three prescribed burns (February 2006, May 2009, and February 2012) since establishment. In late April 2012, 35 saplings were selected and classified based on ocular estimates of needle mass scorch percentages. Mean needle scorch percentages for the lightly (LS), moderately (MS), and severely scorched (SS) saplings were 17, 50, and 99 percent, respectively. The prescribed fire did not change the temporal development of all flushes and their needles. However,...

The southeastern United States possesses a great diversity of woody species and an equally impressive history of wildland fires. Species are known to vary in their flammability, but little is known about southeastern species. We used published data and our own collections to perform standard litter flammability tests on a diverse suite of 25 native overstory trees from the region. Flame heights, duration of flaming and smoldering combustion, and fuel consumption were measured for each species. Species spanned a wide spectrum of flammability, from highly flammable to fire-impeding. The...

At Catahoula Lake in central Louisiana, an internationally important lake for water fowl, hydrologic alterations to the surrounding rivers and the lake itself have led to an expansion of water-elm (Planera aquatic J.F. Gmel.) into the lake bed. In this study, we used dendrochronology and aerial photography to quantify the expansion of water-elm in the lake and identify patterns of expansion. Our data suggest woody vegetation encroached into Catahoula Lake by about 10.4 km2 (30 percent of the lake area) between 1940 and 2007. Encroachment has been concentrated in the northeast near the...

In the southeastern United States, fertilization and weed control treatments, with deployment of genetically improved seedlings planting stock, are routinely used to increase aboveground productivity (Jokela and others 2004).

Groundstory vegetation typically accounts for the greatest proportion of plant diversity in temperate forests, representing a critical structural component and mediating numerous ecosystem processes, including tree regeneration. The effects of thinning on groundstory vegetation have received limited study in bottomland hardwood stands. This study investigated groundstory vascular plant development following thinning in a minor stream bottom in Mississippi. Thinning treatments representing a range of residual basal areas were used to assess groundstory herbaceous and woody vine and shrub...

Carbon (C) in terrestrial ecosystems is one of the main reservoirs in the global C cycle (Schimel 1995). Within these terrestrial ecosystems, soil C in the form of organic matter and plant biomass are the two largest pools of C.

Fire is a natural and important environmental disturbance influencing the structure, function, and composition of longleaf pine (Pinus palustris Mill.) ecosystems. However, recovery of young pines to leaf scorch may involve changes in leaf physiology, which could influence leaf water-use efficiency (WUE). This work is part of a larger seasonal burning study containing three treatments: spring burn, fall burn, and no burn. The study site is a 21.4-ha (53-acre) longleaf pine plantation planted in 2005 and located on the Winn Ranger District of the Kisatchie National Forest in central...