Screening for Control of a Forest Weed: Early Competition Between Three Replacement Species and Calamagrostis canadensis of Picea glauca

• Published in: The Journal of applied ecology 1996-12, Vol.33 (6), p.1517-1526
• Main Authors: Landhausser, Simon M., Stadt, Kenneth J., Lieffers, Victor J.
• Format: Article
• Language: English
• Subjects: Applied ecology; Boreal forests; Calamagrostis canadensis; Ecological competition; Forest ecology; Mortality; Picea glauca; Planting; Planting seasons; Plants; Seedlings; Species
• ISSN: 0021-8901; 1365-2664
• DOI: 10.2307/2404790

1. In a growth chamber experiment, an additive series design was used to test the ability of three replacement species (Trifolium pratense, Trifolium repens, and Epilobium angustifolium) to suppress Calamagrostis canadensis, a problem species in the regeneration of Picea glauca in the mixed-wood associations of the boreal forest. The effects of the replacement species on P. glauca seedlings were also tested. 2. Seedlings of C. canadensis were planted at three different times (same time as the replacement species, 2 and 4 weeks later than the replacement species) into four different densities of the replacement species (229, 601, 1577 and 4174 plants m-2). Seedlings of P glauca were planted into the same four densities of the replacement species and at the same time as the replacement species. 3. Light transmission through the replacement species' canopies decreased with time and increasing density. After 8 weeks, the deepest shade was cast by T. pratense, which reduced light transmission to as low as 4%. 4. The biomass and mortality of the replacement species were not affected by C. canadensis or P. glauca. The replacement species did, however, show different rates of density-dependent mortality, which was attributable to different levels of intraspecific competition. 5. Above-ground biomass accumulation, rhizome production, and mortality in C. canadensis was negatively affected by all three replacement species, especially at the latest planting time. Height and biomass of P. glauca seedlings was also reduced by all replacement species. 6. The results indicate that all three replacement species could be used to control seedling establishment by C. canadensis. Differences between the replacement species are discussed in the light of possible applications in the field of forestry.