Ecophysiological Response of Managed Loblolly Pine to Changes in Stand Environment
Anticipated shifts in our global climate may expose southern pine ecosystems to such environmental stimuli as elevated carbon dioxide and water and nutrient deficiencies (Hansen et al., 1988; Kirschbaum et al., 1990; Peters, 1990). Global climate change may also increase the degree of stress to which trees are presently exposed (Kirschbaum et al., 1990; Peters, 1990). For example, the western extent of loblolly pine (Pinus k&u L.), now dictated by moisture availability for seedling establishment, is predicted to shift eastward with temperature and precipitation changes that may occur with global climate change (Miller et al., 1987). Forest management practices that most effectively respond to global climate change can be identified only if we understand how the physiological and growth processes of trees in forest stands are affected by climate-mediated shifts in such essential resources as light, carbon dioxide, water, and mineral nutrients. The interdependence of above ground and root system processes, and the interactions between these processes and the availability of site resources, emphasize the need to simultaneously study above ground, root-system, and soil responses to environmental change. Tree responses to silvicultural manipulation should also be intensively evaluated so that cultural scenarios that maintain stand productivity and ecosystem integrity can be implemented in the event of global climate change.