Growth and root morphology of planted and naturally-regenerated Douglas-fir and lodgepole pine

Abstract

Root system morphology and growth of Pseudotsuga menziesii var glauca and Pinus contorta var latifolia saplings transplanted from containers to the field were compared with naturally-regenerated saplings of the same species and age. Naturally-regenerated saplings of both species were significantly taller than planted trees, had greater leader growth in the previous year and height/diameter ratios, and smaller tap-root diameters 10 cm below groundline. Naturally-regenerated saplings also had up to 2.3-fold the number of lateral roots compared with planted saplings. Seventy to 79% of all primary lateral roots of naturally-regenerated saplings occurred within the top 10 cm of the soil surface, compared with 30-42% for the planted trees. -from Authors