Survival and growth of black and white spruce seedlings in relation to stock type, site preparation and plantation type in southeastern Manitoba

Abstract

Differences in survival and growth of black and white spruce seedlings planted on boreal mixedwood sites were tested for stock types (transplant versus container), site preparation (Donaren disc trenching versus no trenching), and plantation types (open versus sheltered) in southeastern Manitoba after eight or nine growing seasons. Mortality of open plantation (32.3%) and container stock (32.5%) were significantly higher than sheltered plantation (23.7%) and transplant stock (22.8%), respectively. Donaren trenching slightly reduced the mortality of black spruce but significantly increased the mortality of white spruce. Seedlings of container stock (110 cm) were significantly shorter than transplant stock (157 cm). Significant difference in height was found between open and sheltered plantations for black spruce but not for white spruce. Root collar diameter of container stock (15.6 mm) was significantly smaller than transplant stock (23.1 mm). Root collar diameter in sheltered plantations was significantly larger than that in open plantations for black spruce but not for white spruce. Black spruce open plantation had significantly smaller volume (97 cm3) compare to black spruce sheltered (210 cm3) and white spruce open (175 cm3) and sheltered (229 cm3) plantations. White spruce open plantations also had smaller volume than white spruce sheltered plantations. Container stock had smaller volume (89 cm3) than transplant stock (267 cm3). For transplant stock, strip plantations had a significantly higher volume (329 cm3) than open plantations (204 cm3). Based on above results, we recommend that (1) transplant stock should be used, (2) sheltered plantation site preparation should be used on boreal mixedwood sites, and (3) Donaren disc-trenching is not necessary for planting white spruce. Key words: silviculture, boreal mixedwood site, plantation