RCDlob
An individual tree growth and yield model for loblolly pine that incorporates root-collar diameter at time-of-planting
by Curtis L. VanderSchaaf1 and David B. South2
1Arkansas Forest Resources Center, University of Arkansas at Monticello, Monticello, AR 71656
2School of Forestry and Wildlife Sciences and Alabama Agricultural Experiment Station, Auburn University, AL 36849-5418
RCDlob is a distance-independent individual tree growth and yield model that allows users to input various distributions of root collar diameter (RCD) at time-of-planting for loblolly pine plantations. This growth and yield model is the first that allows the user to vary initial RCD for loblolly pine. It has been implemented into a Visual Basic program that allows the user to input cost data and price data for pulpwood, chip-n-saw and sawtimber sized products. Since the program outputs weight in short tons as well as net-present values, plantation managers can easily calculate the cost/benefit ratio for planting MI seedlings. In the past, many land managers have deferred to the economic goals of hand-planters when defining the desired seedling size for outplanting. Now managers in the Lower-Coastal Plain can determine for themselves how much revenue might be obtained by planting large-diameter loblolly pine seedlings.
As the RCD of a loblolly pine seedling increases, and if proper planting guidelines are followed, survival and long-term growth and yield will be increased. Due to the strong correlation between RCD and seedling root mass (notice in the picture on the right that as RCD increases, the root mass also increases), as RCD increases there will be a greater root mass to compete with other vegetation for limited nutrients and moisture and to protect against mortality due to drought. Since larger RCDs help to reduce transplant shock after seedlings are transferred from a nursery and outplanted, larger RCD seedlings are better able to compete with herbaceous and undesirable woody-vegetation for light relative to smaller RCD seedlings.
RCDlob is Copyright © 2007 Auburn University and University of Arkansas at Monticello
By downloading and using RCDlob you accept the following:
RCDlob is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyright holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings with the software.
Periodic updates will likely be made to RCDlob as data used in model fitting continues to become available. Please check periodically for these updates. We appreciate your interest in RCDlob,
Curtis L. VanderSchaaf and David B. South
