TOLERANCE OF TREE ROOTS TO WATERLOGGING

Abstract
SUMMARY: Rooted cuttings of Sitka spruce and Lodgepole pine were grown in Perspex tubes of peat and the lower portion of the root systems was flooded, while either active or dormant, and at 6° and 15°C. Root survival was assessed after draining the tubes.Root elongation in both species stopped within a few days of flooding, during which the oxygen flux in the peat had declined to zero. Actively growing root tips were more susceptible to waterlogging than the region behind the tip and the latter region remained alive for up to 90 cm below the water‐table in certain treatments.Growing roots of pine were more tolerant to waterlogging than spruce, when assessed in terms of the survival of both the tip and the basal region of the root. By contrast, dormant roots of both species were so tolerant to waterlogging that the tips remained alive and rapid regrowth took place after the soil was drained.