Population dynamics of interior Douglas-fir, Pseudotsuga menziesii var. glauca, in Canada's four Mountain Parks

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Lastra, Rod A.
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Interior Douglas-fir ('Pseudotsuga menziesii' var. ' glauca') is endemic to western north America, reaching its eastern distributional limit in the Alberta Rockies. This study was prompted by growing concerns that past and current land-use practices within the Four Mountain Parks (Banff, Jasper, Kootenay and Yoho National Park) may be detrimental to the long-term ecological integrity of 'old-growth' Douglas-fir stands. Two hundred and twenty plots were enumerated within Banff, Jasper, Yoho and Kootenay National Park to assess the status of these forests. Stands were characterized by estimating percent cover of all vascular and nonvascular plants. In addition, tree size and age data were obtained, and environmental information col ected, from each plot. Species abundances were used to classify the data into three stand-types (I, II and III) and seven sub-types: Ia = very xeric ('n' = 34); Ib = xeric ('n' = 61); IIa = subxeric ('n' = 32); IIb = submesic ('n' = 30); IIc = mesic ('n' = 18); IIIa = subhygric ('n' = 31) and IIIb = hygric (' n' = 14). In addition, statistical analyses were performed to determine relationships between plots, species, and environmental variables. The growth response of Douglas-fir saplings was examined across each stand-type. (Abstract shortened by UMI.)