Abstract
Background and aims: Fine root decomposition contributes significantly to element cycling in terrestrial ecosystems. However, studies on root decomposition rates and on the factors that potentially influence them are fewer than those on leaf litter decomposition. To study the effects of region and land use intensity on fine root decomposition, we established a large scale study in three German regions with different climate regimes and soil properties. Methods In 150 forest and 150 grassland sites we deployed litterbags (100 μm mesh size) with standardized litter consisting of fine roots from European beech in forests and from a lowland mesophilous hay meadow in grasslands. In the central study region, we compared decomposition rates of this standardized litter with root litter collected on-site to separate the effect of litter quality from environmental factors. Results: Standardized herbaceous roots in grassland soils decomposed on average significantly faster (24 ± 6 % mass loss after 12 months, mean ± SD) than beech roots in forest soils (12 ± 4 %; p < 0.001). Fine root decomposition varied among the three study regions. Land use intensity, in particular N addition, decreased fine root decomposition in grasslands. The initial lignin:N ratio explained 15 % of the variance in grasslands and 11 % in forests. Soil moisture, soil temperature, and C:N ratios of soils together explained 34 % of the variance of the fine root mass loss in grasslands, and 24 % in forests. Conclusions: Grasslands, which have higher fine root biomass and root turnover compared to forests, also have higher rates of root decomposition. Our results further show that at the regional scale fine root decomposition is influenced by environmental variables such as soil moisture, soil temperature and soil nutrient content. Additional variation is explained by root litter quality.
| Original language | English |
|---|---|
| Pages (from-to) | 203-218 |
| Number of pages | 16 |
| Journal | Plant and Soil |
| Volume | 382 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 1 Jan 2014 |
| Externally published | Yes |
Funding
Acknowledgments We thank Steffen Both, Jörg Hailer and Uta Schumacher for their help with the field work and technical organization. We thank Michael Bonkowski and Doreen Berner for their contribution to the microbial biomass analyses, Thomas Nauss for the climate data, Valentin Klaus and Stefanie Socher for their contribution to the vegetation survey. We thank Theresa Klötzing for technical support, and Ines Hilke and Birgit Fröhlich for the CN analysis. We thank the managers of the three explor-atories, Swen Renner, Sonja Gockel, Kerstin Wiesner, and Martin Gorke for their work in maintaining the plot and project infrastructure; Simone Pfeiffer and Christiane Fischer for giving support through the central office, Michael Owonibi for managing the central data base, and Markus Fischer, Eduard Linsenmair, Dominik Hessenmöller, Jens Nieschulze, Daniel Prati, François Buscot, Ernst-Detlef Schulze, Wolfgang W. Weisser and the late Elisabeth Kalko for their role in setting up the Biodiversity Ex-ploratories project. The work has been funded by the DFG Priority Program 1374 “Infrastructure-Biodiversity-Exploratories” (SCHR 1181/2-1) and the Max-Planck-Society. Field work permits were issued by the responsible state environmental offices of Baden-Württemberg, Thüringen, and Brandenburg (according to § 72 BbgNatSchG). We thank the two anonymous referees for their helpful comments on the manuscript. Emily Solly and Jakob Zscheischler conducted this work as part of the International Max Planck Research School for Global Biogeochemical Cycles.
Keywords
- Decomposition
- Fine roots
- Land use intensity
- Lignin:N ratio
- Temperate ecosystems