Early growth and floristic diversity of hybrid aspen (Populus x Wettsteinii Hämet-Ahti) plantations on a reclaimed opencast oil shale quarry in north-east Estonia

Abstract

The early growth of the trees, foliar and soil properties, and floristic diversity were studied in 5-year-old hybrid aspen plantations in four sites: A1-levelled oil shale quarry spoil (Calcaric Regosol), A2-levelled quarry spoil covered with the mixture of removed former Calcaric Cambisol horizons, B1-former arable land on Calcaric Cambisol, Chromic Cambisol and Rendzic Leptosol, B2-former arable land on Mollic Planosol. In the quarry area trees had grown significantly faster in site A2. Overall fastest growth was observed on former arable land (B2). Significantly higher pH and lower values of P in the substrate and of foliar N and P were estimated in A1. TWINSPAN classification and DCA ordination showed substantial differences in vegetation composition between the sites. Vegetation of the quarry site A2 resembled more to B1 and B2 than to A1. © 2008 Estonian Academy Publishers.