The amount of forestland in east Texas has been estimated at 11.8 million acres, with approximately 2.5 million acres classified as pine plantations (Edgar et al. 2013). The majority of these plantations are owned by forest industry (71 percent), while non-industrial private forest landowners represent the next largest shareholder (23 percent). Loblolly pine plantations are intensively managed to produce timber, so information is needed to make sound management decisions. The East Texas Pine Plantation Research Project (ETPPRP) has provided growth and yield data since 1982 to help inform forest management decisions in the East Texas region. The ETPPRP is a long-term comprehensive research program that has investigated the factors affecting the management of loblolly and slash pine plantations in East Texas since 1982 (Lenhart et al. 1985). Growth and yield information was first developed for old-field loblolly pine plantations that were common in East Texas in the late 1900s (Lenhart 1972). By the 1980s, old field plantations were replaced with extensively managed loblolly and slash pine plantations. Lenhart (1988, 1996) developed the first growth and yield models for these plantations, which he called non-old-field plantations. These plantations were characterized by minimal site preparation (e.g., pile and burn) and planting with woods run, bare root seedlings. The data used by Lenhart to develop his models represented relatively young plantations (average age = 10 years), so new models were developed when data from older non-old-field plantations became available from the ETPPRP. Lee and Coble developed diameter distribution models for loblolly pine plantations (Lee and Coble 2006) and slash pine plantations (Coble and Lee 2008). Coble (2009) developed a new whole-stand growth and yield model for these plantations that was updated by Allen et al. (2010). Allen et al. (2011) developed a modified stand table projection model, and Coble et al. (2012) developed growth and survival models for individual trees in these plantations. Burrow (2001) developed a basal area growth model for thinned loblolly pine plantations, but did not incorporate his thinning model into existing growth and yield models. These models were improvements over earlier models primarily because they used additional growth data collected in older plantations, but they did not represent a new generation of intensively managed loblolly pine plantations that emerged in the late 1990s. The ETPPRP began collecting growth and yield data in intensively-managed loblolly pine plantations beginning in 2004. These plantations are characterized by substantial investments in site preparation (e.g., bedding and chemical competition control) and planting seedlings with improved genetics. Data are now available to develop growth and yield models for these plantations prior to their first thin. The purpose of this paper is to provide a new whole-stand growth and yield model that describes growth and yield of both intensively managed and extensively managed loblolly pine plantations in east Texas prior to a first thin.
A WHOLE-STAND GROWTH AND YIELD MODEL FOR INTENSIVELY AND EXTENSIVELY MANAGED LOBLOLLY PINE PLANTATIONS IN EAST TEXAS PRIOR TO FIRST THIN BY DEAN W. COBLE JOHN PAUL MCTAGUE YUHUI WENG REPORT 72 FROM THE EAST TEXAS PINE PLANTATION RESEARCH PROJECT ARTHUR TEMPLE COLLEGE OF FORESTRY & AGRICULTURE STEPHEN F. AUSTIN STATE UNIVERSITY NACOGDOCHES, TX 75962 AUGUST 2017
Tell us how this article helped you.