Water content in stem wood of large pine and spruce trees in natural forests in central Sweden

Water relations of large pine and spruce trees were studied by the Mendel University Brno and Swedish Agricultural University Uppsala in central Sweden within the framework of NOPEX project. This particular study was focused on estimation of tree stem water storage and its importance for stand water balance. Proportions of solid matter, water and air in the bulk volume of wood along radii of tree stems were analysed using the gravimetric method. The cores of wood were taken with Suunto increment borer from pine and spruce trees of different social position in two neighbouring stands 50 and 100 year old. Data were interpreted in terms of the sapwood area and volume and water content in different tissues (sapwood and heartwood) and total amounts of water stored in tree stems. Total and available water in stem tissues was distinguished and the radial profile of water content was evaluated. The available water was discussed as an internal source for transpiration on the stand level. (C) 1999 Elsevier Science B.V. All rights reserved.