Biophysical Site Indices for Shade Tolerant and Intolerant Boreal Species
By Chhun-Huor Ung, Pierre Y. Bernier, Frédéric Raulier, Richard A. Fournier, Marie-Claude Lambert, Jacques Régnière. Forestry sciences, 2001
111 citations recorded by the source corpus.
Two variants of a biophysical site index model were derived for two shade-tolerant boreal species (Abies balsamea [L.] Mill., and Picea mariana [Mill.] BSP), and two shade-intolerant boreal species (Populus tremuloides Michx., and Betula papyrifera Marsh.). The reduced model is based on the widely used assumption that the relationship between height and age of dominant trees depends solely on site properties: i.e., four climatic variables (degree-days, vapor pressure deficit, aridity index, and precipitation), and one edaphic variable (soil water-holding capacity). The full model is based on the further assumption that site index also depends on the stand successional stage represented by the dbh distribution index. The reduced model is accurate and unbiased for both intolerant species, but it becomes inaccurate and underestimates the mature stand dominant height for both tolerant species. The full model is equivalent to the reduced model for both intolerant species, but becomes two or three times more accurate and unbiased for both tolerant species. When incorporated into a growth and yield model as the site quality index, the reduced model performs as well as the traditional phytometric model (derived solely from an empirical fit of dominant height and age without any biophysical data) for both intolerant species, but it becomes biased for both tolerant species. By contrast, the full model, when used as a site quality index in the growth and yield model, is unbiased and equivalent to the phytometric model for the four species. These results show that the site index of intolerant species can be solely associated with climatic and edaphic variables, but these variables have to be completed by the successional stage for correctly estimating the site index of the tolerant species. FOR. Sci. 47(1):83–95.
Subfields: Atmospheric Science, Ecology, Mechanics of Materials
View Paper: https://www.semanticscholar.org/paper/a199e545c4d03c1f28573e225a7336dd6576d103
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Citations in the corpus
- Forest, climate and mountain pine beetle outbreak dynamics in Western Canada. (2006, methodology): “An index of aridity (Ung et al. 2001) was used to approximate water deficit.”
- Evaluation of spatial predictions of site index obtained by parametric and nonparametric methods—A case study of lodgepole pine productivity (2005, background): “Various studies have thus attempted to relate SI to biophysical factors (Hunter and Gibson, 1984; Kabzems and Klinka, 1987; Ung et al., 2001; McKenney and Pedlar, 2003), but observed correlations are generally low, and the relationships differ among studies because of no definitive connection betwee”
- Effect of climate change on range expansion by the mountain pine beetle in British Columbia (2003, methodology): “An index of aridity (Ung et al. 2001) was used to approximate water defi cit.”
- Factors affecting interannual variation in growth of western Canadian aspen forests during 1951-2000 (2005, background): “…to incorporate cli- © 2005 NRC Canada matic variation and insect defoliation in stand-based models of aspen growth and yield (e.g., Perala et al. 1996; Ung et al. 2001) and in national- to global-scale models of forest growth and carbon cycling (e.g., Kurz and Apps 1999; Karjalainen et al. 2002).”