Canadian Forest Service Publications

Nitrogen limitations on the early growth of natural and planted montane regeneration. 1995. Koppenaal, R.S.; Hawkins, B.J.; Mitchell, A.K. Pages 41-47 in J.T. Arnott, W.J. Beese, A.K. Mitchell, and J. Peterson, Editors. Montane alternative silvicultural systems (MASS), Proceedings: Workshop. June 7-8, 1995, Courtenay, British Columbia. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, Victoria, BC, FRDA Report 238, copublished by the BC Ministry of Forests. 122 p.

Year: 1995

Available from: Pacific Forestry Centre

Catalog ID: 4224

Language: English

CFS Availability: Order paper copy (free)

Abstract

Foliar nitrogen (N) concentrations were compared between natural and planted amabilis fir (Abies amabilis (Dougl.) Forbes) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) on clearcut, edge, and stand environments of a coastal montane reforestation site. Growth response was assessed by relative height growth rate (RGR), and dry matter partitioning in planted and natural amabilis fir, and RGR in planted western hemlock. Compared to natural regeneration released five years earlier, second-year RGR of planted amabilis fir was 67% and 58% lower on the clearcut and edge plots respectively, reflecting deficient foliar N concentrations in the planted stock the first year after planting. Root:shoot ratio in amabilis fir was lower in planted compared to natural regeneration and may have restricted access to available soil N. Nitrogen concentrations in second-year planted amabilis fir on the clearcut recovered to above the critical level indicating that microclimatic conditions on this plot increased availability of, or access to soil N. Larger root systems of planted amabilis fir on this plot probably facilitated increased N uptake. This was also true of N concentrations in natural hemlock on the clearcut which were higher than in the edge plot. Foliar N concentrations of second-year planted hemlock on the clearcut and edge plots were also deficient compared to their natural counterparts. Different yearly growth rates on the clearcut and outside edge plots may be the result of changing foliar nutrient concentrations in planted trees.

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