East Texas Pine Plantation Research Project

The ETPPRP was established with the purpose of providing quantitative information and decision making tools for managing pine plantations in the western Gulf Coastal Plain region. While loblolly pine growth continues to be a primary focus, the ETPPRP embraces a broader mandate and scope of modeling work that includes other species and production objectives across the region.

Given our broader mission, we are seeking new cooperators who would benefit from partnering with us. Please contact Dr. Yuhui Weng (wengy@sfasu.edu) for details about how to become an ETPPRP member.

The ETPPRP is managed by Dr. Yuhui Weng, director and assistant professor of forestry, andJason Grogan, research associate.

The ETPPRP employs two to three graduate students to conduct an array of research projects. We place an emphasis on the recruitment of high-quality graduate students pursuing either a master’s or doctoral degree who are interested in growth and yield modeling, quantitative ecology or quantitative silviculture. The ETPPRP also annually hires three to four undergraduate field technicians to collect measurements for the ETPPRP research plots.

Phase I Study: Dr. J. David Lenhart led the ETPPRP’s phase I study, which was initiated in 1982. The study installed a total of 256 permanent monumented plots in unmanaged East Texas pine plantations (175 plots in loblolly pine plantations and 81 in slash pine plantations) between 1982-84. Each plot is located in a different plantation and consists of two subplots, and each subplot is 100-ft square (0.23 acres). All planted pines within a subplot were tagged and numbered for sequential data collection: dbh, total height, height to live crown, crown class, and fusiform rust incidence. One subplot is being utilized for model development and the other subplot for model evaluation.

As of Fall 2015, due to acts of nature and man, only 32 original plots remain (27 plots in loblolly pine and 5 in slash pine plantations). Data collection from the Phase I plots were stopped thereafter.

Ongoing Phase I data-based projects include, but are not limited to, understanding how stand density, climate or soil affect pine growth rates and subsequently incorporating that information into the regional pine management.

Phase II Study: given the advance in pine silviculture, beginning in 2004, the ETPPRP installed 136 plots in intensively-managed loblolly pine plantations located in Texas and Louisiana.  Each plot had a size of 0.23 acre (100 by 100 foot), which is the same size as that of the Phase I plot. However, unlike the Phase I plots, which were insulated from all subsequent management activities, each plot received the same treatment as the entire plantation.  Individual tree dbh, height, height to live crown, crown class, and fusiform rust incidence were recorded every three years. In the future, up to a maximum of 180 plots in loblolly pine plantations will be installed to fill deficiencies in the database (e.g., North East Texas).

Phase II data-based research focuses on (1) developing growth and yield models for managing the regional, intensively-managed loblolly pine plantations and (2) incorporating climate and soil variables into the G&Y models.

Thinning Study of Loblolly Pine Plantations: The ETPPRP initiated a new study to measure the thinning response of first-thinned East Texas loblolly pine plantations in a randomized block design experiment. Four thinning treatment levels were applied in each block: a) no thin, b) thin to 225 tpa residual density (moderate thin), c) thin to 150 tpa residual density (heavy thin), and d) thin to 300 tpa residual density (light thin).  Thinning was done by removing every fifth row, thinning from below and/or removing diseased and damaged trees in residual rows to meet the thinning target density.  As of Fall 2019, the study installed thinned plots on 18 sites of intensively-managed loblolly pine plantations across East Texas and Western Louisiana.

The study focuses on (1) understanding affects of thinning on loblolly pine growth and yield; (2) incorporating thinning effects into the G&Y models; and (3) understanding affects of thinning on pine plantations’ environment such as needle decomposition and nutrient release and soil nutrient.

1982 -1999

Lenhart, J. D., E. V. Hunt, Jr. and J. A. Blackard.  1985.  Establishment of permanent growth and yield plots in loblolly and slash pine plantations in East Texas.  P. 436-437 In Eugene Shoulders  (ed.) Proc. Third Biennial South. Silv. Research Conf., U.S.D.A. For. Serv. Gen. Tech. Rep. SO-54.  589 p.

Lenhart, J. D., E. V. Hunt, Jr. and J. A. Blackard.  1986.  Site index equations for loblolly and slash pine plantations on non-old-fields in East Texas.  South. J. Appl. For. 10(2):109112.  

Hunt, E. V., Jr. and J. D. Lenhart.  1986.  Fusiform rust trends in East Texas.  South. J. Appl. For.  10(4):215-216.  

Lenhart, J. D., T. J. Wiswell, T. L. Hackett and C. J. Laman.  1987.  Estimating the amount of wood,  bark and needles per tree for planted loblolly and slash pines in East Texas.  P. 7073 In Proc. Fourth South.  Biomass Energy Res. Conf.  280 p.

Lenhart, J. D.  1987.  Estimating the amount of wood per acre in loblolly and slash pine plantations in East Texas.  P.  485-488 In D. R. Phillips (ed.)  Proc. Fourth Biennial South. Silv. Research Conf.,  U.S.D.A. For. Serv. Gen. Tech. Rep. SE-42.  598 p.

Lenhart, J. D.  1987.  Maintaining and preserving permanent growth and yield research plots.  P.  525-526 In D. R. Phillips (ed.)  Proc. Fourth Biennial South. Silv. Research Conf., U.S.D.A. For. Serv. Gen. Tech. Rep. SE-42.  598 p.   

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-fields in East Texas. South. J. Appl. For. 11(3):147-151.  

Lenhart, J. D.  1988.  Diameter distribution yield prediction system for unthinned loblolly and slash pine plantations on non-old-fields in East Texas.  South. J. Appl. For.  12(4):239242.

Lenhart, J. D., W. T. McGrath and T. L. Hackett.  1988.  Fusiform rust trends in East Texas: 1969-87.  South. J. Appl. For.  12(4):259-261.

Tang, D. and J. D. Lenhart.  1990.  Loblolly pine tree quality dynamics in the forested region of East Texas, U.S.A.  5th Workshop of IUFRO Project Group 07-00.  Chengdu, Sichuan, PRC.

Tang, D. and J. D. Lenhart.  1990.  Factors affecting tree quality in the loblolly pine plantations in the forested region of East Texas, U.S.A.  5th Workshop of IUFRO Project Group 0700.  Chengdu, Sichuan, PRC.  September 5-14, 1990.  

Arabatzis, A. A., T. G. Gregoire and J. D. Lenhart. 1991.  Fusiform rust incidence in loblolly and slash pine plantations in East Texas.  South. J. Appl. For.15(2):79-84.

Tang, D., J. D. Lenhart and G. D. Kronrad. 1992.  Development of a provisional tree quality index for planted loblolly pines in East Texas.  South. J. Appl. For. 16(2):106-110.

Lenhart, J. D., G. D. Kronrad and M. S. Fountain.  1993.  Comparison of planted loblolly and slash performance in southeast Texas.  South. J. Appl. For.  17(1):26-31.

Valentine, H. T., A. R. Ludlow and G. M. Furnival. 1993.  Modeling crown rise in even-age stands of sitka spruce and loblolly pine.  For. Ecol. & Mgt.

Houghton, D. R. and T. G. Gregoire.  1993.  Minimum subsamples of tree heights for accurate estimation of loblolly pine plot volume.  South. J. Appl. For.  17(3):124-129.

Lenhart, J. D., T. G. Gregoire, G. D. Kronrad and A. G. Holley. 1994.  Characterizing fusiform rust incidence and distribution in East Texas.  South. J. Appl. For.  18(1):29-34.

Adams, D. E., J. D. Lenhart, A. B. Vaughn and J. Lapongan.  1996.  Estimating survival of East Texas loblolly and slash pine plantations infected with fusiform rust.  South. J. Appl. For.   20(1):30-35.

Lenhart, J. D. 1996.  Total and partial stand-level yield prediction for loblolly and slash pine plantations in East Texas.  South. J. Appl. For.  20(1):36-41.

Lee, Y. J. and J. D. Lenhart.  1997.  Estimating crown height for unthinned planted pines in East Texas. South. J. Appl. For.  21(3):130-133.

Lee, Y. J. and J. D. Lenhart. 1998.  Influence of planting density on diameter and height in East Texas pine plantations.  South. J. Appl. For. 22(4)241-244.

2000 -2015

Lee, Y.J. and D.W. Coble. 2002.  A survival model for unthinned loblolly pine plantations that incorporates non-planted tree competition, site quality, and incidence of fusiform rust. Bioresource Technology 85(3):301-308.

Lee, Y.J. and D.W. Coble. 2002.  Modeling survival for unthinned slash pine plantations in east Texas under the influence of non-planted tree basal area and incidence of fusiform rust. Texas Journal of Science 54(4):325-338.

Coble, D.W., and Y.J. Lee.  2004. Fusiform rust trends in east Texas: 1969 to 2002.  P. 153-157 In Connor, Kristina F. (ed.) Proc. 12th Biennial South. Silv. Research Conf., U.S.D.A. For. Serv. Gen. Tech. Rep. SRS-71.  594 p.

Lee, Y.J., and D.W. Coble.  2006.  A new diameter distribution model for unmanaged loblolly pine plantations in east Texas.  South. J. Appl. For.  30(1):13-20.

Coble, D.W., and Y.J. Lee.  2006.  Use of a generalized sigmoid growth function to predict site index for unmanaged loblolly and slash pine plantations in east Texas.  P. 291-295  

Connor, Kristina F. (ed.) Proc. 13th Biennial South. Silv. Research Conf., U.S.D.A. For. Serv. Gen. Tech. Rep. SRS-92.  640 p.

Coble, D.W., and K. Hilpp.  2006.  Compatible cubic-foot stem volume and upper-stem diameter equations for semi-intensive loblolly pine trees in east Texas.  South. J. Appl. For.  30(3):132-141.

Coble, D.W., and Y.J. Lee.  2008.  A new diameter distribution model for unmanaged slash pine plantations in east Texas.  South. J. Appl. For. 32(2):89-94.

Coble, D.W. 2009. A new whole-stand model for unmanaged loblolly and slash pine plantations in east Texas. South. J. Appl. For. 33(2):69-76.

Coble, D.W., and Y.J. Lee.  2010.  Self-referencing site index equations for unmanaged loblolly and slash pine plantations in east Texas.  Stanturf, John A., ed. 2010. Proceedings of the 14th biennial southern silvicultural research conference. Gen. Tech. Rep. SRS-121. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 614 p.

Coble, D.W., and Y.J. Lee.  2011.  A mixed-effects height-diameter model for individual loblolly and slash pine trees in east Texas.  South. J. Appl. For. 35(1):12-17.

Allen, M.G. II, D.W. Coble, Q.V. Cao, J. Yeiser, and I. Hung.  2011.  A modified stand table projection model for unmanaged loblolly and slash pine plantations in east Texas.  South. J. Appl. For. 35(3):115-122.

Coble, D.W., Q.V. Cao, and L. Jordan.  2012.  An annual tree survival and diameter growth model for loblolly and slash pine plantations in east Texas. South. J. Appl. For. 36(2):7984.

Coble, D.W. 2013. Modeling thinning in east Texas loblolly and slash pine plantations.  In: Guldin, James M., ed. 2013. Proceedings of the 15th biennial southern silvicultural research conference. e-Gen. Tech. Rep. SRS-GTR-175.
Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 197-199 - See more at: http://www.srs.fs.usda.gov/pubs/43591#sthash.bAEtrFK4.dpuf

Cao, Q., and D.W. Coble. 2014. Deriving a diameter distribution from stand table data.  Forest Science 60(4):628-635.   

Informal Project Reports

Report No. 1 Fusiform rust occurrence.  E. V. Hunt, Jr. and J. D. Lenhart.   November, 1985.  18 p.

Report No.  2 Tree quality.  J. D. Lenhart and E. V. Hunt, Jr.   December, 1985.  16 p.

Report No.  3 Estimating site index.  J. A. Blackard.    December, 1985.  10 p.

Report No.  4 Predicting individual tree height.  J. A. Blackard.    December, 1985.  27 p.

Report No.  5 Estimating the cubic foot volume of individual loblolly pine trees planted in East Texas.  T. J. Wiswell, J. A. Blackard and J. D. Lenhart.    October, 1986.  11 p.

Report No.  6 Estimating the green weight of individual loblolly pine trees planted in East Texas.  T. J. Wiswell, J. A. Blackard and J. D. Lenhart.  October, 1986.  10 p.

Report No.  7. Estimating the dry weight of individual loblolly pine trees planted in East Texas.  T. J. Wiswell, J. A. Blackard and J. D. Lenhart.  October, 1986.  9 p.

Report No.  8. Estimating the cubic foot volume of individual slash pine trees planted in East Texas.  T. L. Hackett.  October, 1986.  11 p.

Report No.  9. Estimating the green weight of individual slash pine trees planted in East Texas.  C. J. Laman.  October, 1986.  10 p.

Report No. 11. Stand structure and yield of loblolly pine plantations on non-old-fields in East Texas. J. D. Lenhart  November, 1986.  32 p.

Report No. 12. Stand structure and yield of slash pine plantations on non-old-fields in East Texas.  J. D. Lenhart  November, 1986.  32 p.

Report No. 13. Estimating dry weight of understory woody plants in East Texas.  H. C. Reeves and J. D. Lenhart.  December, 1986.  12 p.

Report No. 14.   Stumpage price trends of pine sawtimber and pulpwood in East Texas 1977-86.  J. D. Lenhart and K. T. Adair.  February, 1987.  8 p.

Report No. 15. Predicting individual tree height of planted loblolly and slash pines in East Texas, update: 1987. C. R. Dixon.  December, 1987.  8 p.

Report No. 16. Stand structure and yield of loblolly pine plantations in East Texas, update:  1987.  J. D. Lenhart.  December, 1987.  23 p.

Report No. 17. Stand structure and yield of slash pine plantations in East Texas, update:  1987.  J. D. Lenhart.  December, 1987.  23 p.

Report No. 18. Fusiform rust occurrence in East Texas Pine Plantations: 1969-87.  J. D. Lenhart and T. L. Hackett.  February, 1988.  7 p.

Report No. 19.   Estimating survival for East Texas Pine Plantations.  J. D. Lenhart and T. L. Hackett.  February, 1988. 10 p.

Report No. 20. Stumpage price trends of pine sawtimber and plpwood in East Texas, update:  1977-87.  J. D. Lenhart and K. T. Adair.  March, 1988.  11 p.

Report No. 21. A FORTRAN computer program for estimating yield of East Texas pine lantations.  J. D. Lenhart.  April, 1988.  18 p.

Report No. 22. A computer program in BASIC for estimating yield of East Texas pine plantations.  T.  L. Hackett and T. M. Hartz.  October, 1988.  5 p.

Report No. 23. Environmental factors influencing diameter development within loblolly pine plantations in East Texas.  P. Malim.  January, 1989.  11 p.

Report No. 24. HyperStand 1.0:  A HyperCard computer program for estimating yield of East Texas Pine Plantations.  E. L. Taylor and A. G. Holley.  February, 1989.  16 p.

Report No. 25. FRMPS:  A Forest Resource Management Planning Simulator for East Texas Pine Plantations.  T. Hartz.  January, 1990.  4 p.

Report No. 26. HYPERSTAND 2.0:  Estimating yield of East Texas pine plantations (Update to Hyperstand 1.0).  A. G. Holley and E. L. Taylor.  January, 1990.  7 p.

Report No. 27.   Site index equations for loblolly and slash pine plantations in East Texas. Update: 1993.    A. B. Vaughn, J. Lapongan and J. D. Lenhart.  May, 1993.  6 p.

Report No. 28. Tree content and taper functions for planted loblolly and slash pine trees in East Texas.   Update:6/93.   Revised:9/93.  J. Lapongan, A. B. Vaughn and J. D. Lenhart.  September, 1993.  9 p.

Report No. 29. Site index equations for loblolly and slash pine plantations in East Texas. Update: 1994. Members of FOR 317 class - Spring ‘94.  April, 1994.  7 p.

Report No. 30. A guide for timing initial tree harvests in East Texas loblolly and slash pine plantations.  J. D. Lenhart and H. A. Ross.  September, 1994.  19 p.

Report No. 31. Observed growth rates of loblolly and slash pine plantations in East Texas.  H. A. Ross and J. D. Lenhart.  September, 1994.  20 p.

Report No. 32. Trends of non-straight tree stems in loblolly and slash pine plantations in East Texas 1985-94.  H. A. Ross and J. D. Lenhart.  December, 1994.  14 p.

Report No. 33. Climate and growth.  C. C. Brown, H. C. Reeves and J. D. Lenhart.  January, 1995.  5 p.

Report No. 34. Influence of soil and topography features on ability of land in East Texas to grow loblolly and slash pine plantations.  H. A. Ross, A. J. Londo and J. D. Lenhart  March, 1995.  12 p.

Report No. 35. Pine and hardwood stumpage price trends for lumber/plywood ... chip-n-saw ...pulpwood timber in East Texas and Louisiana through 1994.  K. B. Scott and J. D. Lenhart.  March, 1995. 4 p.

Report No. 36. Yield prediction spreadsheets written in Lotus 1-2-3 for PCs and Excel for Macintoshes.  M. McBroom and J. D. Lenhart. March, 1995. 2 p.

Report No. 37. Site index equations for loblolly and slash pine plantations in East Texas.  Update:  1995  Members of FOR 317 class - Spring ‘95.  April, 1995.  6 p.

Report No. 38. Average observed fusiform rust transition paths.  O. Schabenberger, T. G. Gregoire and J. D. Lenhart.  May, 1995.  5 p.

Report No. 39. Observed average characteristics of unthinned loblolly and slash pine plantations in East Texas.  K. B. Scott and J. D. Lenhart.  October, 1995.  18 p.

Report No. 40. Influence of plantation variables on crown height.  Y. J. Lee and J. D. Lenhart.  January, 1996.  13 p.

Report No. 41. Perils Facing ETPPRP Plots (1982-1995). J. D. Lenhart.  February, 1996.  4 p.

Report No. 42.  High/low counties.  C. Vanderschaaf and J. D. Lenhart.  April, 1996.  6 p.

Report No. 43. Site index equations for loblolly and slash pine plantations in East Texas Update:  1996.  FOR 317 students - Spring ‘96.  April, 1996. 6 p.

Report No. 44. Scenic beauty and plantation age.  Y. J. Lee, H. A. Londo and J. D. Lenhart.  May, 1996.  4 p.

Report No. 45. Loblolly pine plantations in East Texas: Thinned and unthinned - Total wood flow comparison: A simulation.  J. D. Lenhart and C. Vanderschaaf.  June, 1996.  23 p.

Report No. 46. Loblolly pine plantations in East Texas. Two harvest schedules: No thinning & final harvest at 25 years & Thin at 10 years & final harvest at 25 years. Sawlog/Venee

Report No. 47. Loblolly pine plantations in East Texas. Two harvest schedules: No thinning & final harvest at 25 years & Thin at 15 years & final harvest at 25 years. Sawlog/Veneer wood comparison: A simulation.  J. D. Lenhart and J. Allen  November, 1996.  26 p.

Report No. 48.   Loblolly pine plantations in East Texas. Two harvest schedules: No thinning & final harvest at 30 years & Thin at 15 years & final harvest at 30 year. Sawlog/Veneer wood comparison: A simulation.  J. D. Lenhart and J. Allen  November, 1996.  26 p.

Report No. 49. Loblolly pine plantations in East Texas. Two harvest schedules: No thinning & final harvest at 30 years & Thin at 20 years & final harvest at 30 years. Sawlog/Veneer wood comparison: A simulation  J. D. Lenhart and J. Allen  November, 1996.  26 p.

Report No. 50. Site index equations for loblolly and slash pine plantations in East Texas  Update:  Fall  1996.  FOR 317 students - Fall ‘96.  November, 1996 6 p.

Report No. 51. Slash pine plantations in East Texas. Thinned and Unthinned - total wood flow  comparison.  A simulation.  J. Allen and J. D. Lenhart  March, 1997.  24 p.

Report No. 52. Location.  Location.  Location.   Location.  J. Allen and J. D. Lenhart  March, 1997.  8 p.

Report No. 53. Slash pine plantations in East Texas. Two harvest schedules: No thinning & final harvest at 30 years & Thin at 15 years & final harvest  at 30 years. Sawlog/Veneer wood comparison: A simulation J. D. Lenhart and J. Allen  April, 1997.  26 p.

Report No. 54. Assessment of early estimation of site index - loblolly pine plantations in East Texas.  J. D. Lenhart and J. Allen.  September, 1997.  8 p.

Report No. 55. Observed growth trends - cubic feet wood and bark total stem per acre – loblolly and slash pine plantations - East Texas.  J. D. Lenhart and J. Allen  September, 1997.  8 p.

Report No. 56. Observed growth trends - basal area per acre in square feet - loblolly and slash pine plantations.  J. D. Lenhart and J. Allen.  September, 1997.  8 p.

Report No. 57. Observed growth trends - quadratic mean diameter - loblolly and slash pine plantations - East Texas.   J. D. Lenhart and J. Allen.  September, 1997.  8 p.

Report No. 58. Observed growth trends - average total height...ten tallest trees - loblolly and slash pine plantations - East Texas.  J. D. Lenhart and J. Allen.  September, 1997.  8 p.

Report No. 59. Site index equations for loblolly and slash pine plantations in East Texas Update:  1997.  FOR 317 students - Fall 1997.  November, 1997. 6 p.

Report No. 60. Observed per-acre volume growth trends for 28 individual observations of unthinned lobolly pine plantations East Texas.  A. Burrow.  July, 1998. 30 p.

Report No. 61. Observed per-acre basal area growth trends for 28 individual observations of unthinned lobolly pine plantations East Texas.  A. Burrow.  July, 1998. 30 p.

Report No. 62. Site index equations for loblolly and slash pine plantations in East Texas  Update:  1998.  FOR 317 students - Fall 1998.  November, 1998. 6 p.    

Report No. 63. Site index equations for loblolly and slash pine plantations in East Texas Update:  Fall 2000.  FOR 317 students - Fall 2000.  October, 2000. 6 p.    

Report No. 64 Observed growth and yield of loblolly and slash pine plantations in East Texas  Shiaolin Cheng and Dean W. Coble  April, 2004.

Report No. 65. Stumpage price trends of pine and hardwood sawtimber and pulpwood in East Texas and Louisiana.  Shiaolin Cheng and Dean W. Coble  November, 2004.     

Report No. 66. Metric volume and biomass prediction equations for loblolly and slash pine trees planted in unmanaged pine plantations in East Texas.  Dean W. Coble, Young-Jin Lee, and J. David Lenhart  November, 2004. 18 p.

Report No. 67. A whole-stand growth and yield model for unmanaged east Texas loblolly and slash pine plantations.  Micky G. Allen II, Dean W. Coble, I-Kuai Hung, and Jimmie Yeiser  August, 2010. 12 p.   

Report No. 68. Observed growth and yield of loblolly pine plantations in East Texas.  Katherine A. Pendergast and Dean W. Coble  November, 2013 (Revised December 2014). 21 p.   

Report No. 69. Observed growth and yield of loblolly and slash pine plantations in East Texas.  Katherine A. Pendergast and Dean W. Coble  May, 2014 (Revised December 2014). 31 p.