Understorey vegetation as an indicator of forest site potential in southern Finland

Abstract

The relationship between site characteristics and understorey vegetation composition was analysed with quantitative methods, especially from the viewpoint of site quality estimation. Theoretical models were applied to an empirical data set collected from the upland forests of S Finland comprising 104 sites dominated by Scots pine (Pinus sylvestris), and 165 sites dominated by Norway spruce (Picea abies). A new model for the estimation of site quality at sites with a known understorey vegetation composition was introduced. It is based on the application of Bayes' theorem to the density function of site quality within the study area combined with the species-specific presence-absence response curves. Using this method, a jackknife estimate of site index H100 was calculated separately for pine- and spruce-dominated sites. -from Author