Five Decades of Structural and Compositional Changes in Managed and Unmanaged Montane Stands: A Case Study from South-East Europe

Abstract

The recent research has indicated that restoration of old-growth attributes such as large-sized living trees and snags contributes to sustaining biodiversity on the landscape level. The extent to which these attributes are restored, maintained, or diminished by total salvage logging, selection silviculture, and strict protection has been partly investigated in the past. However, studies examining the influence of partial salvage logging are largely absent. Thus, we compared long-term structural and compositional changes in three montane beech-fir-spruce stands in Serbia that were exposed to different management regimes for five decades (partial salvage logging, selection silviculture, and strict protection). Tree species composition of partly salvaged stand and selection stand significantly differed from that in the adjacent unmanaged stand. However, the diameter distributions of compared stands often exhibited the same structural forms in certain periods, despite the greater share of large-size trees in the unmanaged stand. The study indicated that managing for old-growth attributes such as large trees may be possible by applying not only rotated sigmoid and negative exponential structures, but also the increasing-q diameter structure as high basal areas in studied beech-fir-spruce stands did not impair the ingrowth of young trees when conifers dominated the upperstory. The study further revealed that partial salvaging may serve as a sound alternative to promoting old-growth attributes such as large veteran trees and snags.