Stand structure as the basis of diversity index

• Published in: Forest ecology and management 1999-03, Vol.115 (2), p.213-220
• Main Authors: Lähde, Erkki, Laiho, Olavi, Norokorpi, Yrjö, Saksa, Timo
• Format: Article
• Language: English
• Subjects: Between-stand diversity; Biological and medical sciences; Boreal forest; boreal forests; dead wood; evaluation; forest inventory; Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Forestry; Fundamental and applied biological sciences. Psychology; genetic variation; logs; site factors; size; spatial distribution; species diversity; stand development; stand structure; Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Stem distribution; tree age; Within-stand diversity
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/S0378-1127(98)00400-9

Abundance of tree species and variation in tree size, age and genetic composition are the most relevant components of diversity in a forest stand. The aim of this study was to develop a within-stand diversity index and classification for between-stand diversity to meet these requirements. This, what may be called LLNS diversity index, was assessed by using the following indicator variables: stem distribution of live trees by tree species (stems ha −1), standing and fallen dead trees by tree species (m 3 ha −1), occurrence of special trees (number/significance) and charred wood (m 3 ha −1). The index was introduced as a scoring table for field use and as a mathematical formula for research and computerisation use. In the test material, this index served to differentiate the development classes of forest stands and site-types fairly well. The value of the index was at its highest in unmanaged, old-growth stands dominated by Norway spruce ( Picea abies (L.) Karst.). In single-tree selection stands, regularly all-sized stand structure resulted in a high diversity index values whereas low thinning, by evening out stand structure, reduced diversity. Classification of between-stand diversity was based on within-stand diversity scores, which were allocated to four quality levels (Excellent, Good, Satisfactory, Poor) by site-type.