Treesearch

Growth data over the past 10 years from loblolly pine (Pinus taeda L.) plantations established across the natural range of the species were linked with annual rainfall data over the same period to evaluate the impact of drought on stand growth. Regression procedures were used to determine (1) whether dominant height growth or basal area growth or perhaps both were correlated with local rainfall, (2) whether annual rainfall was a significant predictor of annual growth in the presence of other stand and site variables, and (3) whether prediction equations could be developed that would...

A new thinning model was proposed for loblolly pine (Pinus taeda L.) and slash pine (P. elliottii Engelm.) plantations in east Texas. The new model follows the index of suppression methodology introduced by Pienaar (1979). It was implemented in a new whole stand growth model for loblolly and slash pine plantations in east Texas (Coble 2009). The new thinning model performed similarly to existing Pienaar-type models for east Texas and the Southeastern United States across a range of site quality. The predicted basal area development consistently approached the unthinned counterpart, which...

Tree diameter at breast height (d.b.h.) is often predicted from total height (model 1a) or both total height and number of trees per acre (model 1b). These approaches are useful when Light Detection and Ranging (LiDAR) data are available. LiDAR height data can be employed to predict tree d.b.h., and consequently individual tree volumes and volume/ ha can be obtained for the tract. In this paper, we will examine alternative methods of predicting d.b.h. from total height and crown length (model 2a), or from total height, crown length, and number of trees per acre (model 2b), based on the...

Size-density trajectories on the logarithmic (ln) scale are generally thought to consist of two major stages. The first is often referred to as the density-independent mortality stage where the probability of mortality is independent of stand density; in the second, often referred to as the density-dependent mortality or self-thinning stage, the probability of mortality is related to stand density. Within the self-thinning stage, segments of a size-density trajectory consisting of a nonlinear approach to a linear portion, a linear portion (maximum size-density relationship dynamic thinning...

In plantation forestry, several silvicultural treatments can be row oriented. When rows are treated individually, planting trees in wider rows may result in lower silvicultural treatment cost, facilitate future operations, such as thinning and fire fighting, and provide a longer period with open canopy conditions. All these scenarios could provide benefit to landowners, depending on management objectives. Few studies have considered the effects of asymmetrical spacing on tree growth, stand yield, or wood quality. This study examines tree and stand attributes for loblolly pine (Pinus taeda...

Chopper® GEN2™ is a new imazapyr product for use in forestry site preparation. A single treatment (32 ounces of Chopper® GEN2™ per acre) was applied at three timings on three sites (Louisiana, Mississippi, and Virginia) to test the effect of application timing on treatment efficacy. Hardwood control was excellent for all applications. Pine growth varied by site, but all treatments resulted in excellent pine growth. Pine stem volume was 5 to 10 times greater in treated plots as compared to untreated plots.

The efficacy of adding Oust® XP to woody release treatments was evaluated on second-year pine plantations in Texas, Mississippi, and South Carolina. Overall, the residual control of herbaceous weeds on these sites was excellent the growing season following application. Pine height and diameter growth was evaluated for 5 years following application. Generally, the treatments of high rates of Arsenal AC alone and all treatments with Oust® XP resulted in significantly improved height and diameter growth.

Three site prep vegetation control systems were compared on two Piedmont and two Upper Coastal Plain sites. Systems were (1) a one-time site prep application of Chopper® GEN2™ 2, (2) a one-time application of Chopper® GEN2™ tank mixed with sulfometuron, and (3) two applications consisting of site prep with Chopper® GEN2™ followed by herbaceous weed control with Arsenal AC plus sulfometuron in March/April following planting. Each of these systems was repeated with a July/August, September, and October site prep timing. The third system, consisting of two applications, resulted in better...

In April 2008, the Upland Hardwoods Ecology and Management Research Work Unit of the U.S. Forest Service, Southern Research Station began a long-term cooperative study to describe forest ecosystem response to three oak (Quercus spp.) shelterwood regeneration treatments in the central hardwoods region of the United States. Pretreatment inventory data from 10 mature, mixed-oak forest stands on North Carolina Wildlife Resources Commission Game Lands were input into the Forest Vegetation Simulator (FVS) to analyze the long-term forest ecosystem response to the following oak shelterwood...

The study compares the relationship between 15 measures of canopy structure and height growth of underplanted yellow-poplar (Liriodendron tulipifera L.) seedlings. Investigators used 4 midstory removal intensities to create a structural gradient across fifty 0.05-ha experimental plots; removals resulted in a range of canopy cover between 51 to 96 percent. Twelve 1-year-old containerized yellow-poplar seedlings were planted within each plot. Height growth was monitored through two growing seasons (2004 to 2005). Investigators used regression analysis (n = 50) to predict 2-year height growth...