Distribution of Picea rubens, global warming, and system theory approach

The red spruce forest in Great Smoky Mountains National Park (GSMNP) has recently experienced growth and population decline. Greenhouse gases and acidic pollutants are implicated, but uncertainty exists within the scientific community about the roles of these factors. This could be because most evaluations are based on reductionistic and mechanistic methods that do not consider the full complexity of hierarchically expressed direct and indirect factor interactions. More holistic thinking afforded by open-system theory may be useful. In this study, open-system theory is employed to find relationships between forest decline and global warming. Determining factors are seen as manifested in cross-boundary flows of energy, matter, and information. Study hypotheses are : 1) Distribution and growth of Picea rubens in GSMNP are determined by habitat suitability expressed by multiple hierarchically organized, direct and indirect interactions among system factors; 2) Habitat suitability of Picea rubens in GSMNP is influenced by global warming expressed through these direct and indirect interactions among system factors; 3) Spatiotemporal change of Picea rubens' distribution in GSMNP associated with global warming is the result of changes in habitat suitability over time and space; and 4) Indirect interactions among system factors are the dominant influences in determining the distribution and growth of Picea rubens in GSMNP. These four hypotheses are tested by employing life-cycle envirograms to organize factor information, ecosystem modeling employing Stella simulation, and spatial modeling in ArcGIS.