High-Resolution Map on Base Saturation: an Essential Tool for Forest Management in Austria

Stockholm

2024

3376

Bandaufführung

40005313

Understanding soil nutrient status and its spatial distribution is crucial for effective forest management, especially in the face of climate change. This study focuses on the development and significance of a high-resolution base saturation map based on nutrient classes for a forest area of 1 million hectares in a complex topographic and geological environment in the federal state of Styria, Austria. This study emphasizes the importance of such a map in light of existing data limitations and future challenges posed by climate change. In a first step, pedotransfer functions were developed using laboratory analysis of soil chemical parameters from 400 soil pits in 4 depth layers. In order to expand the dataset and enhance coverage, an additional 1400 assessment plots were characterized solely by field descriptive soil assessment. This dataset of 1800 assessment plots served as the basis for subsequent analyses. In a next step, a combination of base saturation, soil pH and mineralogical composition was identified as robust parameters for defining soil nutrient classes in form of base saturation types. Different digital soil mapping techniques, including Random Forest and Artificial Neural Networks, were then utilized to generate projections based on the expanded dataset. These techniques enabled
the development of a high-resolution base saturation map that captures the spatial variability of base saturation types and thus soil chemical parameters. The validation of this modeling approach was conducted by comparing the model outputs with the presence of tree species at the forest sites, average tree species growth, and plant sociological communities. Results demonstrated a strong correlation between the base saturation map and tree species distribution, highlighting the model's accuracy in capturing important ecological relationships. Furthermore, the growth of tree species aligned closely with the predicted nutrient classes, validating the utility of the map for assessing growth potential. The map serves as a valuable tool for forest planners, enabling them to identify areas of specific interest and subsequently develop targeted interventions and adaptive management strategies (e.g. tree species selection), addressing current and future challenges in respect to nutrient status.