Submitted to: Agroforestry Systems
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/2/2010
Publication Date: 6/16/2011
Citation: Burner, D.M., Dwyer, J., Godsey, L. 2011. Stocking rate-mediated responses of mid-rotation loblolly pine in west-central Arkansas 2. Profitability. Agroforestry Systems. 81(3):279-285. Interpretive Summary: Small farms tend to be less profitable than large farms, and alternative forest products derived from pine plantations could substantially increase small farm profitability. Pine straw has been so poorly appreciated for its potential profitability as a landscaping product that large areas in the southern US have little or no commercial industry. Using data from 13 loblolly pine plantation designs at 14 years of age, researchers at ARS-Booneville and University of Missouri, Columbia developed an Excel model which allows the user to predict timber production and profitability across a production cycle by varying any of a wide array of inputs: tree spacing, growth rate, thinning intensity, discount rate, and timber yield. We predicted that for some stands, pine straw harvesting could nearly double plantation value compared to no pine straw. The model could be expanded to address costs/benefits of other timber and non-timber products, helping family farms plan and budget for agroforestry and timber operations. Results emphasize the potential profitability of pine straw and should encourage landowners with suitably designed pine plantations to consider harvesting this valuable commodity for increased farm profitability.
Technical Abstract: Relatively few studies have compared loblolly pine (Pinus taeda L.) growth in an array of plantation designs commonly used in forestry and agroforestry practices. Our objective was to develop an economic model to estimate financial outputs at mid-rotation (14-yr-old) for 13 loblolly pine plantations having 546 to 3067 trees/ha (stocking rate, TPH) at planting. The Excel model allowed costs, returns, growth, and production scenarios to be varied to calculate net present value (NPV) and years to “break even” with and without pine straw. Plantations with greater than or equal to 2100 TPH and no pine straw harvest had negative NPV and a relatively long break-even period than other plantations at a 5% discount rate. Pine straw harvesting nearly doubled NPV at about 1500 TPH compared to no pine straw, and substantially reduced years to break even at less than or equal to 1500 TPH. There was little difference in NPV between multiple-row plantations. Single-row plantations with greater than or equal to 1500 TPH should be considered only if pine straw was harvested or a lower discount rate was used. Pine straw harvesting probably would be impractical for the single-row plantations with less than or equal to 1100 TPH, and the 2-row and 3-row multiple-row plantations due to low stocking rate and partially open canopies. The model demonstrated the potential financial benefit for harvesting pine straw with timber, especially in the south-central US where pine straw is an underutilized resource, and could be expanded to include costs/benefits of other agroforestry products.