Predicting Changes in Forest Growing Season (FGS) in the Transitional Climate of Poland on the Basis of Current Grid Datasets

Abstract

The observed climate change determines the silvicultural and productive perspectives of the different species. The use of stand growth simulators, which are important tools for predicting future tree growth, requires verified and consistent data, such as length of forest growing season (FGS). The aim of this study is to determine the current and future FGS on the territory of Poland, which has a highly variable transition climate between maritime and continental types. The analysis is based on the WorldClim grid dataset corrected with the constructed model based on the FGS derived from 245 meteorological stations covering the whole territory of the country. In addition, predictions of changes in FGS depending on different climate scenarios were considered. The results show that the inclusion of geographical location components, i.e., longitude, latitude and especially altitude, is important for the correction of FGS calculated on the basis of raster datasets such as WorldClim. The prediction of climatic changes shows a significant increase in FGS duration in Poland, ranging from 18 to 52 days, mainly affecting the mountainous regions with the shortest actual FGS.