Abstract: Forest health is a complex concept including many ecosystem functions, interactions and values. We develop a quantitative system applicable to many forest types to assess tree mortality with respect to stable forest structure and composition. We quantify impacts of observed tree mortality on structure by comparison to baseline mortality, and then develop a system that distinguishes between structurally stable and unstable forests. An empirical multivariate index of structural sustainability and a threshold value (70.6) derived from 22 nontropical tree species’ datasets differentiated structurally sustainable from unsustainable diameter distributions. Twelve of 22 species populations were sustainable with a mean score of 33.2 (median = 27.6). Ten species populations were unsustainable with a mean score of 142.6 (median = 130.1). Among them, Fagus grandifolia, Pinus lambertiana, P. ponderosa, and Nothofagus solandri were attributable to known disturbances; whereas the unsustainability of Abies balsamea, Acer rubrum, Calocedrus decurrens, Picea engelmannii, P. rubens, and Prunus serotina populations were not. This approach provides the ecological framework for rational management decisions using routine inventory data to objectively: determine scope and direction of change in structure and composition, assess excessive or insufficient mortality, compare disturbance impacts in time and space, and prioritize management needs and allocation of scarce resources.
Keywords: baseline mortality; climate change; forest health; invasive species
Export to BibTeX
MDPI and ACS Style
Cale, J.A.; Teale, S.A.; West, J.L.; Zhang, L.I.; Castello, D.R.; Devlin, P.; Castello, J.D. A Quantitative Index of Forest Structural Sustainability. Forests 2014, 5, 1618-1634.
Cale JA, Teale SA, West JL, Zhang LI, Castello DR, Devlin P, Castello JD. A Quantitative Index of Forest Structural Sustainability. Forests. 2014; 5(7):1618-1634.
Cale, Jonathan A.; Teale, Stephen A.; West, Justin L.; Zhang, Lianjun I.; Castello, David R.; Devlin, Peter; Castello, John D. 2014. "A Quantitative Index of Forest Structural Sustainability." Forests 5, no. 7: 1618-1634.