Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Spruce and birch growth in pure and mixed stands in Sweden.

Abstract

An experiment was established in a 38-year-old, mixed species stand with a 14.5-m birch overstory (Betula species) and a 3-m spruce understory (Picea abies). Treatments were birch shelterwood with 300 or 600 stems/ha and spruce understory with 1500 stems/ha, grown separately or mixed on 14 plots. Height growth of spruce was not significantly affected by birch shelterwood during a 36-year observation period, but spruce trees under birch shelter were more slender. Volume growth of spruce was slightly reduced by birch shelter, and volume growth of birch significantly reduced by a spruce understory. Total growth was higher for mixed than for single-species plots.