Compatible Cubic-Foot Stem Volume and Upper-Stem Diameter Equations for Semi-intensive Plantation Grown Loblolly Pine Trees in East Texas

摘要

The Max-Burkhart taper equation was used to develop compatible taper and volume equations for semi-intensive plantation grown loblolly pine (Pinus taeda L.) trees in East Texas, Semi-intensive plantations in East Texas are characterized by some form of mechanical site preparation, a burn, possibly chemical weed control, improved seedlings if planted after 1985, and, possibly, a midrotation thinning and/or fertilization. The equations in this study were compared with those of Lenhart et al. [Lenhart,J.D., T.L Hackett, C.J Laman, T.J. Wiswell, and J,A, Blackard. 1987 Tree content and taper functions for loblolly and slash pine trees planted on non-old field in east Texas, South J, Appl, For, 10(2)109-112.] and Baldwin and Feduccia [Baldwin, V C. Jr.,and DP Feduccia. 1991 Compatible tree-volume and upper-stem diameter equations for loblolly and slash pines in the West Gulf Region. South, J. Appl For, 10(2)109-112,] using independent data. The new equations ranked first (sum of ranks = 9) in terms ofpercent bias and percent SEE for inside-bark predictions of upper-stem diameters and cubic-foot volumes, while the Lenhart et al, [Lenhart, J.D., TL. Hackett, CJ Laman, T.J Wiswell, and J.A. Blackard. 1987. Tree content and taper functions for loblollyand slash pine trees planted on non-old field in east Texas. South J. Appl For. 10(2)109-112.] ranked second (sum of ranks = 17) and Baldwin and Feduccia [Baldwin, V.C. Jr., and D.P. Feduccia. 1991. Compatible tree-volume and upper-stem diameter equations for loblolly and slash pines in the West Gulf Region. South. J. Appl. For. 10(2)109-112.] ranked third (sum of ranks = 22). For outside-bark predictions of volumes and diameters, Baldwin and Feduccia [Baldwin, V.C. Jr., and DP. Feduccia. 1991. Compatible tree-volume and upper-stem diameter equations for loblolly and slash pines in the West Gulf Region. South. J Appl For. 10(2)109-112.] ranked first (sum of ranks = 12), while the new equations ranked a close second (sum of ranks = 13) and Lenhart et al. [Lenhart, J.D., T.L, Hackett, C.J Laman, T.J. Wiswell, and J.A, Blackard, 1987. Tree content and taper functions for loblolly and slash pine trees planted on non-old field in east Texas, South J. Appl, For, 10(2)109-112.] ranked third (sum of ranks = 20). We recommend using the new equations for loblolly pine trees up to a 16-in. dbh and provide examples to illustrate their use.