Height-growth and site-index curves for jack pine in north central Ontario

Abstract

Height-growth patterns for jack pine (Pinusbanksiana Lamb.) were studied using stem analyses from dominant and codominant trees on 141 plots in north central Ontario. All plots were in natural, well-stocked, even-aged stands 50 years of age or older. Data from 32 of the 141 plots were randomly selected to confirm results, the remaining 109 plots were used for computing the curves. Height-growth curves were developed using a five-parameter Chapman–Richards nonlinear regression that expressed height as a function of age and site index. A site-index prediction equation was also computed using a similar model that expressed site index as a function of age and tree height. Estimated site index using height-growth curves based on the 109 computation plots agreed closely with site index observed from stem analyses on the 32 confirmation plots. Major results were as follows: (i) height-growth curves based on breast-height age were more accurate than curves based on total age; (ii) polymorphic height-growth patterns were related to site index, becoming more curvilinear as site index increased; (iii) average height-growth patterns were similar for jack pine growing on four glacial landforms: shallow and deep moraines, outwashed glacial sands, and lacustrine clays and silts; and (iv) height-growth patterns for ages less than 50 years were very similar to patterns of the commonly used Plonski curves for jack pine site classes in Ontario, but after 50 years, height growth was somewhat better for all sites than predicted by the Plonski curves.

Growth and yield comparisons for red pine, white spruce and black spruce plantations in northwestern Ontario

“…The good site indices in our studies are similar to good site indices reported for plantations in other areas of the Upper Great Lakes, where site indices have been identified based on stem analyses or on measurements from long-term growth and yield studies. For example our good red pine site indices are similar to the good red pine site indices reported by Ek (1971), Alban (1979), Beckwith et al (1983), Berry (1984), Liechty et al (1986), and Carmean and Thrower (1995). Our good white spruce site indices are similar to good white spruce site indices reported by Stiell and Berry (1973), Rauscher (1987), and Carmean et al (2006a).…”

“…The estimated seven years for planted trees to reach breast height is based on stem analysis used for constructing local site index curves for red pine plantations (Carmean and Thrower 1995) and white spruce plantations in northwestern Ontario (Carmean et al 2006a). Stem analysis used for site index curves for natural even-aged black spruce stands in northwestern Ontario (Carmean et al 2006b) also indicate that about seven years are needed for trees to reach breast height.…”

Polymorphic site index curves for black spruce and trembling aspen in northwest Ontario

“…Corrections for each individual tree height-age curve were made for a small bias that occurs where height at sectioning points underestimates actual height attained for a particular year (Carmean 1972, Dyer and Bailey 1987, Carmean and Lenthall 1989. This bias occurs because sectioning points will almost always be at some intermediate point along the annual leader rather than at the terminal bud.…”

Polymorphic site index curves for jack pine in Northern Ontario

“…Most older site index curves are anamorphic curves based on harmonizing methods but most recent site index curves use stem-analysis data, breast-height age and nonlinear regression models capable of expressing polymorphic height-growth patterns . Only a few jack pine site index curves are available (Gevorkiantz 1956, Plonski 1974, Carmean and Lenthall 1989, Ker and Bowling 1991, Cieszewski et al 1994, Lewis et al 1996 despite the wide range and great economic importance of jack pine.…”

“…Polymorphic jack pine site index curves based on stemanalysis methods for North Central Ontario (Carmean and Lenthall 1989) showed: (a) site index curves based on breastheight age were more precise than curves based on total age; (b) polymorphic height-growth patterns were related to level of site index with height growth becoming more curvilinear as site index increased; (c) even though site index varied greatly polymorphic patterns of height growth were similar f o~ trees growing on mineral soils developed from four major upland landforms; and (d) height-growth patterns for ages less than 50 years were similar to the commonly used Plonski (1 974) anamorphic site class curves for Ontario, but after 50 years height growth was better than predicted by the Plonski curves.…”