Comparison of Planted Loblolly and Slash Pine Performance in Southeast Texas

The performance of young (less than 10 yr) loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm. )pine trees was compared on planted sites in southeast Texas. Performance was compared for: total tree height; tree diameter; height o live tree crown; tree volume index,; incidence offusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shir ai f. sp. fusiforme ) ;crookedness of stems; and survival rates. For these young trees, slash pine tended to perform better in southeast Texas than loblolly pine in total tree height, tree diameter, stem size, height to first live branch and stem straightness. However, loblolly pine was less susceptible to fusiform rust than slash pine, and its mortality rate was lower than slash pine. However, based on the performance of these young plantations, a recommendation the preferred pine species to plant in southeast Texas might be premature. South. J. Appl. For. 17(1): 26-31. Approximately 25% of the 11 million acof orestland in East Texas have been planted to loblolly (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.). Of these plantations, an estimated 15-20% are slash pine, and almost all the planted slash pine are located in southeast Texas (McWilliams and Lord 1988). However, slash pine planted anywhere in East Texas is an exotic well west of its natural range. Loblolly pine is native to East Texas, and natural and planted stands of this species occur throughout the region. Comparisons of the performance of loblolly and slash pine plantations within their natural ranges in South Carolina, Georgia, and Florida have shown that, in general, on most sites, loblolly performs as well as or better than slash pine (Cole 1975, Van Lear et al. 1977, Haines and Gooding 1983, Outcalt 1984, Borders and Harrison 1989). Exceptions include a droughty site in South Carolina on which slash pine performed better than loblolly pine (Van Lear et al. 1977). In Florida, slash pine performance xceeded that of loblolly pine on disked sites (Outcalt 1984). On intensively prepared sandhill sites in Florida, slash pine outperformed loblolly pine, but on sandhill sites in South Carolina, 1oblolly and slash pine performed in a similar manner (Bums 1973). In Georgia, slash pine and 1oblolly pine performed similarly on two soil groups characterized by poor drainage (Borders and Harrison 1989). A comparison of slash and loblolly plantations in northwest Louisiana (outside the natural range of slash pine) indicated comparable growth and yield values (Clason and Cao 1982). A performance comparison in westem Louisiana (outside natural range of slash pine), southeastem Louisiana, and southem Mississippi showed that both species in general grew equally well (Shoulders 1976). A comparison of the performance of these two species in southeast Texas at relatively young ages (3-15 yr) might assist in the management of existing southeast Texas pine plantations, as well as deciding which species to replant after final harvest of the current plantations. The goal of this study was to answer the research question: How do the performances of the two species compare at early ages, when planted in southeast Texas? Plantation Measurements Information from the East Texas Pine Plantation Research Project (ETPPRP) was utilized in this study. The ETPPRP is a long-term, comprehensive r search endeavor initiated by the School of Forestry, Stephen F. Austin State University, m 1982 with support from East Texas forest industries. 1 To provide data to drive analyses, the ETPPRP has installed 246 permanent research plots in 1oblolly and slash pine plantations on industrial land throughout East Texas. Loblolly plots are located in plantations from the Gulf Coast to the Red River, while slash plots are only located in plantations in Southeast Texas. Plots were established and first measured during 1982-1884. Remeasurements are conducted on a 3 -yr cycle with three cycles completed to date. Fusiform rest (Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp.fusiforme) resistant planting stocks were not used in plantations ampled by the ETPPRP. During plot establishment, a goal was to achieve a wide distribution of samples across ite factors uch as: geographic • Support from participating companies---Champion Intemational Corporation, International Paper Company,Louisiana-Pacific Corp. and TempleInland Inc.--is appreciated.