Phenotypic variation in cone and needle characters of Pinus banksiana Lamb. (jack pine) in Northwestern Ontario / by Madeline L. Maley

To assess the patterns of phenotypic variation in cone and
\nneedle characters of jack pine relative to spatial, climatic and
\necological data, collections were made from ten trees in each of 64
\nsites in northwestern Ontario. Nineteen cone and forty needle
\ncharacters were measured on five cones and five needles per tree.
\nClimatic data from 27 Canadian and 10 American weather stations
\nin and surrounding the study area were interpolated, using a
\ngeographic information system, to produce weather data for each
\ncollection site. Vegetation and soil data for each collection site
\nwere determined using the system developed by the Ontario Ministry
\nof Natural Resources in the Northwestern and North Central regions
\nfor the Forest Ecosystem Classification program.
\nDiscriminant analysis indicated that the populations in the
\nstudy areas formed a single group but were spatially organized into
\ntwo groups, west and east, including the Armstrong area, of Lake
\nNipigon. A trend surface of the discriminant scores revealed a
\nsteep dine at a longitude of 88?15', Nipigon area. Simple
\nregression of discriminant scores against the spatial, climatic and
\necological data indicated that the patterns of variation expressed
\nby cone and needle characters may be a result of adaptation to local
\nenvironments.(see document for elevations)
\nMultiple regression coefficients from regressions of spatial and
\nclimatic data against discriminant scores for both cone and needle
\ndata were compared with the variance component among groups
\nfrom the nested analysis of variance to assess the amount of the
\ntotal variation attributable to the local environment. The
\ncomparison revealed that most of the variation among sites could
\nbe explained by spatial and climatic data. In addition, a steep dine
\ncould be discerned at a longitude of 88?15? on the the trend surface
\nof maximum June temperature.
\nThe correlations of the patterns of variation with the spatial
\nand climatic data suggest that climate may be the causal agent for
\nthe patterns of variation in cone and needle characters in
\nNorthwestern Ontario. However, the patterns of cone and needle
\ncharacters are similar suggesting that the modern patterns of
\nvariation may be a result of two migration routes or two refugia.

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