Assisted lodgepole pine regeneration on reclamation sites using logging slash as both a mulch and natural seed source
Cirelli, D., T. Vinge and V. Lieffers. 2016. NRC Research Press
Abstract
In this study we tested the efficacy of establishing lodgepole pine (Pinus contorta Dougl.) from seed using woody mulch produced from slashed tree tops from a pine harvesting site; this mulch contained the closed serotinous cones of the lodgepole pine. Mulch was spread on prepared reclamation sites at 0, 1, 3 and 5 cm depth. Broadcast seeding of pine was also done at 0 and 1 cm of mulch depth. Mulch cover that was 1 cm thick was the preferred treatment as it produced 17,000 seedlings ha-1 by year 3 after treatment while being similar in seedling density to the 3 and 5 cm treatments. When 50,000 seeds ha-1 were added, seedling density increased more on the sites with 1 cm of mulch than the 0 cm sites. Soil temperature was lower and temperature extremes were reduced under the mulch layer compared to the control plot. The plots with 1 cm mulch also had higher soil moisture in the mineral layer than the plots with 0 cm of mulch. A thin layer of woody mulch therefore, provided both a source of pine seed and the covering of the ground provided a more benign environment for the establishment of pine germinants.
Key Words
lodgepole pine, mulch, reclamation, regeneration, recruitment
