Articles | Volume 2, issue 1
SOIL, 2, 49–61, 2016
SOIL, 2, 49–61, 2016

Original research article 21 Jan 2016

Original research article | 21 Jan 2016

Tree species and functional traits but not species richness affect interrill erosion processes in young subtropical forests

S. Seitz1, P. Goebes1, Z. Song1, H. Bruelheide2,3, W. Härdtle4, P. Kühn1, Y. Li4, and T. Scholten1 S. Seitz et al.
  • 1Department of Geosciences, Soil Science and Geomorphology, Eberhard Karls University Tübingen, Rümelinstrasse 19–23, 72070 Tübingen, Germany
  • 2Geobotany and Botanical Garden, Martin Luther University Halle-Wittenberg, Am Kirchtor 1, 06108 Halle, Germany
  • 3German Centre for Integrative Biodiversity Research (iDIV) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103 Leipzig, Germany
  • 4Institute of Ecology, Faculty of Sustainability, Leuphana University Lüneburg, Scharnhorststrasse 1, 21335 Lüneburg, Germany

Abstract. Soil erosion is seriously threatening ecosystem functioning in many parts of the world. In this context, it is assumed that tree species richness and functional diversity of tree communities can play a critical role in improving ecosystem services such as erosion control. An experiment with 170 micro-scale run-off plots was conducted to investigate the influence of tree species and tree species richness as well as functional traits on interrill erosion in a young forest ecosystem. An interrill erosion rate of 47.5 Mg ha−1 a−1 was calculated. This study provided evidence that different tree species affect interrill erosion differently, while tree species richness did not affect interrill erosion in young forest stands. Thus, different tree morphologies have to be considered, when assessing soil erosion under forest. High crown cover and leaf area index reduced interrill erosion in initial forest ecosystems, whereas rising tree height increased it. Even if a leaf litter cover was not present, the remaining soil surface cover by stones and biological soil crusts was the most important driver for soil erosion control. Furthermore, soil organic matter had a decreasing influence on interrill erosion. Long-term monitoring of soil erosion under closing tree canopies is necessary, and a wide range of functional tree traits should be considered in future research.

Short summary
Different tree species affect interrill erosion, but a higher tree species richness does not mitigate soil losses in young subtropical forest stands. Different tree morphologies and tree traits (e.g. crown cover or tree height) have to be considered when assessing erosion in forest ecosystems. If a leaf litter cover is not present, the remaining soil surface cover by stones and biological soil crusts is the most important driver for soil erosion control.