Planted Pines Have Severely Deformed Roots
Nearly two-thirds of planted lodgepole pines have severely deformed roots, compared with 9 percent of naturally regenerated pines, finds a study near Prince George in central British Columbia.
Roots misshapen to this extent stunt a sapling's growth.
Planted trees grow faster than naturally sown trees, but not if the planted trees have extremely poor root form. Planted pines with the least amount of root deformities have the greatest annual height and diameter growth. Growth of natural lodgepole pines seems unaffected by their root architecture.
The abnormalities that commonly appear in planted but not natural trees include missing taproot, several roots braided together and lateral roots not extending in all directions. All contribute to a compacted and interwoven root system that likely arises from growing new seedlings in containers. Also prevalent are J-shaped roots resulting from improper planting technique.
Moderate to severe root deformities persisted in 95 percent of planted lodgepole pine examined, aged 3 to 10 years old, in the Sub-boreal Spruce biogeoclimatic zone of central BC. So far the trees are not lacking in stability due to their root structure. Only pines with a low total area of root cross-section have an elevated mortality rate.
Jeanne A. Robert and B. Staffan Lindgren. 2006. Relationships between root form and growth, stability, and mortality in planted versus naturally regenerated lodgepole pine in north-central British Columbia. Canadian Journal of Forest Research. 36(10): 2642-2653.