Factors regulating tree-herb competition in young hybrid poplar plantations

  • Author / Creator
    Henkel-Johnson, David C
  • Hybrid poplar plantations have the potential to produce large amounts of biomass for the forest industry, but the young trees are sensitive to competition. This research attempted to quantify the influence of factors regulating competition in hybrid poplar plantations under four years old. The effects of competition varied with growing site, indicating an interaction with abiotic conditions. Nonetheless, perennial grasses overall appeared to be highly detrimental to tree growth in comparison to most forb species, especially for younger trees. Additionally, vegetation directly adjacent to the tree stem (within 0.5 m) was responsible for most of the competition for above-ground resources, and controlling near-stem vegetation resulted in large growth increases, but only for the fast-growing ‘Okanese’ clone. These results suggest that plantation managers should prioritize control of grasses while reducing above-ground biomass of all vegetation within 0.5 m of the tree stem for maximum productivity.

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  • Type of Item
  • Degree
    Master of Science
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    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.