Canadian Forest Service Publications
Polymorphic site productivity functions for black spruce in relation to different ecological types in Northern Ontario. NEST technical report TR-033. 1996. Larocque, G.R.; Parton, W.J.; Archibald, D.J. Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, Sainte-Foy, Quebec. Information Report LAU-X-119E, Ontario Ministry of Natural Resources, Northeast Science and Technology (NEST), South Porcupine, Ontario. 19 p.
Available from: Laurentian Forestry Centre
Catalog ID: 16720
CFS Availability: PDF (request by e-mail)
Polymorphic site productivity functions were derived for black spruce (Picea mariana [Mill.] B.S.P.) in the Clay Belt region of Northern Ontario using data from permanent sample plots. The main intent was to relate different height growth patterns to the characteristics of the operational groups of the forest ecosystem classification implemented for Ontario's Clay Belt. Five models based on the logistic, Chapman-Richards and Weibull functions were tested. Dummy variables were incorporated into the models to represent the influence of different operational groups on site productivity. The integration of basic ecological information and polymorphic site productivity functions provided a good explanation of the growth patterns within each operational group. Thus, although some operational groups had very close site index values at age 50, they were characterized by different patterns of long-term height development. Of the various models tested, the Weibull and Chapman-Richards functions, constrained to satisfy the condition that top height equals site index at age 50, produced the best fit.
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