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Strategies and case studies for incorporating ecophysiology into southern pine tree improvement programs

Informally Refereed

Abstract

Both genetic and environmental influences on tree growth are expressed through physiological processes. This central, integrating role of physiology has made the field of forest ecophysiology a major area of biological research for the past several decades. Specifically, forest ecophysiology is the study of how plants interact with their abiotic and biotic environment to acquire the resources (sunlight, CO2. water, and nutrients) needed to produce assimilates neceisary for growth, reproduction, competition with other plants. and defense against insects and disease. Because of their commercial and ecological importance, southern pines, especially loblolly pine (Pinus taedo L.) have been intensively studied by ecophysiologists. Although an exhaustive review of the ecophysiological literature is not possible here. examples of the physiological and morphological determinants of growth that have been studied in southern pines include the following: leaf area development (Gresham 1982, Martin and Jokela 20041, crown and canopy structure (Kinerson et al. 1974, Gillespie et al. 1994). light interception (Dalla-Tea and Jokela 1991, Will et al. 2001). carbon fixation (Bormann 1956, Teskey et al. 1987, Ellsworth 2000, Yang et al. 20021, respiration (Brix 1962, Kinerson et al. 1977, Maier et al. 1998), carbon allocation (Kuhns and Gjerstad 1988, Retzlaff et al. 2001b). tree water relations and stand water balance (Knauf and Bilan 1974, Seiler and Johnson 1985, Fites and Teskey 1988. Phillips and Oren 2001), root structure and function (Sword et al. 1996, Topa and Sisak 1997, Wu et al. 2000), and nutrient uptake and utilization dynamics (Switzer et al. 1966, Birk and Vitousek 1986, Dalla-Tea and Jokela 1994, Barron-Gafford et al. 2003). Important areas of emphasis have included genetic variation in physiology and morphology (Tharnes 1963, Ledig and Perry 1967, Bilan et al. 1977, Bongarten et al. 1987, McCarvey et al. 2004), physiological responses to silvicultural treatments (Johnson 1990, Murthy et al. 1997, Samuelson et al. 2001), and the potential effects of pollution and climate change on physiology (Sasek et al. 1991, Tissue et al. 1993, Teskey 1997, Oren et al. 2001). Taken together, the broad and deep coverage of ecophysiological investigations with southern pines (in particular, loblolly pine) have enabled a level of biological understanding that is rivaled in onIy a few other forest tree species, such as Douglas-fir (Pseudotsuga menziesii), Scots pine (Pinus sylvestris)and radiata pine (Pinus radiata).

Citation

Martin, Timothy A.; Dougherty, Philip M.; Topa, M.A.; McKeand, Steve E. 2005. Strategies and case studies for incorporating ecophysiology into southern pine tree improvement programs. SJAF 29(2): 70-79
https://www.fs.usda.gov/research/treesearch/21168