Comparison of unmanaged and managed trojan fir–scots pine forests for structural complexity

Abstract

Unmanaged forests may exhibit a higher degree of biodiversity compared to managed forests. We examined and compared the stand structure, density, and volume of deadwood components of managed and unmanaged mixed forests of Trojan fir (Abies nordmanniana subsp. equi-trojani [Asch. & Sint. ex Boiss] Coode & Cullen)–Scots pine (Pinus sylvestris L.) in northern Turkey. The single-tree selection method has been employed in the managed forests. Density of large live trees ha–1, density of standing deadwood (SDW) ha–1, and volume of lying deadwood (LDW) (m3 ha–1) were calculated for both treatments (i.e. managed or unmanaged). Results showed that unmanaged forests had significantly higher density of large live trees and SDW compared to managed forests (P < 0.005). In addition, a lower amount of LDW was observed in the managed forests (P < 0.005). Our data suggest that the managed forests’ lack of Scots pine trees in small-and middle-sized diameter classes indicates the potential risk of conversion of these mixed stands into pure Trojan fir forests. Initial results highlight the importance of large tree retention in managed stands to enhance biological diversity.