The structural complexity index SCI is useful for quantifying structural diversity of Estonian hemiboreal forests

• Published in: Forest ecology and management Vol. 490; p. 119093
• Main Authors: Põldveer, Eneli, Potapov, Aleksei, Korjus, Henn, Kiviste, Andres, Stanturf, John A., Arumäe, Tauri, Kangur, Ahto, Laarmann, Diana
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2021
• Subjects: Conservation forests; Managed forests; Rehabilitation forests; Spatial stand structure; Stand structural heterogeneity; Conservation forests; Managed forests; Rehabilitation forests; Stand structural heterogeneity; Spatial stand structure
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2021.119093

•Considering structural complexity of forest stands is increasingly important in forest management.•Structural complexity index SCI ranges from 1.36 to 10.78 in Estonian hemiboreal forests.•Structural complexity index SCI is dependent from forest management history and site fertility.•Forest management in Estonia may apparently be shifting towards favouring more complex forest structures. Comprehensive description and quantification of stand structure is needed for managing or maintaining forests as complex systems. The tree position and diameter based structural complexity index SCI was used to quantify the structural heterogeneity of forest stands in Estonia. The aims of the study were to determine if SCI is related to the conventional stand characteristics used for forest management planning and to assess the direct impact of silvicultural treatments on stand structural heterogeneity. The SCI for hemiboreal forests in Estonia ranged from 1.36 to 10.78, being highest in conservation forests on fertile sites (7.42 ± 1.20), followed by managed forests on fertile sites (4.74 ± 1.44), managed forests on poor sites (4.00 ± 1.02), conservation forests on poor sites (3.85 ± 0.87), and lowest in rehabilitation forests (2.64 ± 0.69). The mean SCI between forest groups and site types differs significantly, except in managed and protected forests growing on poor sites. The SCI is positively associated with commonly measured stand characteristics, indicating that stand structural heterogeneity reflected in SCI is higher for older stands with larger trees, higher deadwood quantity and biomass. The results also show that species diversity promotes stand structural diversity. SCI is a promising method for providing quantitative assessments of multidimensional forest stand structure in Estonia.