Regeneration and surface condition trends following forest harvesting on peatlands.
Groot, A.;
NODA/NFP Technical Report Year: 1996 Issue: No. TR-26 Pages: v + 12 + 6 pp. Ref: 20 ref.
1996
บทคัดย่อ
Advance growth amounts, vegetation cover, and soil surface conditions were measured prior to harvesting in 11 peatland black spruce (Picea mariana) stands near Kapuskasing, Ontario. Remeasurements were carried out 1, 3, 6 and 10 growing seasons after harvesting was conducted using three different methods. Approximately 80% of the preharvest stocking persisted after winter harvesting, 70% after summer harvesting with wide-tyred skidders, and 60% after summer harvesting with narrow-tyred skidders. Most advance growth mortality took place within the first year after harvesting, and advance growth quantities were stable thereafter. The establishment of substantial numbers of black spruce seedlings following harvest eventually eliminated differences in total black spruce stocking among the various harvest methods. When equipment traffic is restricted to repeatedly used trails, an alternating pattern of taller and shorter tree can result. Thus, it appears likely that careful mechanized logging will le
ad to positively skewed diameter structures similar to those created earlier in the 20th century by horse logging. Height growth increased with increasing tree height both for black spruce advance growth and for postharvest origin black spruce seedlings. Postharvest seedlings lagged advance growth in height development by 6 to 8 years. Summer harvesting with narrow-tyred skidders created more deep ruts than did the other harvesting methods. Within areas harvested by this method, survival of advance growth and postharvest seedling establishment decreased with increasing initial deep rut cover. Rapid invasion of Sphagnum spp., grasses, and sedges occurred on deeply rutted areas. Rut cover decreased rapidly and did not differ among the various harvest methods after 6 growing seasons. The better growth of postharvest origin black spruce seedlings on rutted areas was likely related to differences in site types between more and less heavily rutted areas, and to more fertile substrates created by heavy disturbance.