Nelson Thiffault , François Hébert, Robert Jobidon

Planted Picea mariana growth and nutrition as influenced by silviculture x nursery interactions on an ericaceous-dominated site

Thiffault N., Hébert F., Jobidon R. (2012). Planted Picea mariana growth and nutrition as influenced by silviculture x nursery interactions on an ericaceous-dominated site. Silva Fennica vol. 46 no. 5 article id 918. https://doi.org/10.14214/sf.918

Abstract

We aimed at evaluating the interacting effects of silvicultural and nursery practices on planted black spruce (Picea mariana (Mill.) BSP) dimensions, growth, survival and nutrition, 8 years following planting on a carefully logged boreal stand heavily invaded by Kalmia angustifolia L. and Rhododendron groenlandicum (Oeder) Kron & Judd. We also evaluated functional traits related to light and nutrient acquisition and key environmental resource availability to interpret treatment impacts on spruce seedling leaf traits and growth. An experimental black spruce plantation, consisting in a randomized block split-split-split plot design with 13 replicates was established in northeastern Quebec (Canada). Scarification (single-pass, double-pass), fertilization at the time of planting (control; macronutrients only; macro + micronutrients), stock type (container-grown; bare-root), and initial foliar N concentration (4 increasing levels) treatments were applied, and measurements were performed 5 and 8 years following planting. Double-pass scarification significantly increased soil temperature and reduced the competition cover, compared to the single-pass treatment. As a result, double-pass scarification promoted seedling growth over the single-pass treatment, and influenced the expression of other treatment effects. However, the relative gains associated with the second scarification pass have to be balanced against the supplemental investment involved by the treatment before being recommended. Our results point to variable effects of fertilization at planting to stimulate seedling initial growth. In this ecosystem, it appears that the silvicultural gains of this treatment depend on the variable of interest. Bare-root seedlings grew faster than containerized seedlings in the most intense site preparation treatment, but the differences have limited silvicultural impacts.

Keywords
fertilization; black spruce; scarification; Kalmia angustifolia; Rhododendron groenlandicum; stock type

Received 24 July 2012 Accepted 9 October 2012 Published 31 December 2012

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