Long-term soil warming changes the quantity but not the composition of primary metabolites of tree fine roots
- 1Division of Terrestrial Ecosystem Research, Department of Microbiology and Ecosystem Science, Center of Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
- 2State Key Laboratory for Subtropical Mountain Ecology of the Ministry of Science and Technology and Fujian Province, Fujian Normal University, 350007, Fuzhou, China
- 3Department of Forest Ecology and Soils, Federal Research and Training Centre for Forests, Natural Hazards and Landscape - BFW, Seckendorff-Gudent Weg 8, 1131 Vienna, Austria
- 4Department of Soil Ecology, Bayreuth Center of Ecology and Environmental Research (BAYCEER), University of Bayreuth, Dr.-Hans-Frisch-Straße 1-3, 95448, Bayreuth, Germany
Abstract: Climate warming poses major threats to temperate forests, but the response of plant root metabolism has remained unclear. Understanding and predicting the impact of climate warming on the root metabolome represents a grand challenge and a major opportunity to predict the belowground functioning of forests in a warmer climate. We here studied the impact of long-term soil warming (>14 years, ambient versus +4 °C) on the fine root metabolome across three seasons (spring, summer, and autumn) for two years in a spruce-dominated mountain forest in the Austrian Limestone Alps. Root primary metabolites were analyzed with a liquid chromatography-mass spectrometry metabolomics platform (LC-Orbitrap MS). A total of 44 primary metabolites were identified in roots (19 amino acids, 12 organic acids, and 13 sugars). Warming and season had significant effects on total primary metabolite concentration, but no interaction effect. Warming increased the amino acid and sugar concentrations but did not affect organic acids. This may be explained by increased activity of the protein amino acid (such as arginine, glycine, and lysine) biosynthesis and metabolism and/or of root carbohydrate metabolism and transport under warming. The non-metric multidimensional scaling (NMDS) showed that soil warming was not significantly affecting the primary metabolite profiles, but year and season had significant effects. Season impacted primary metabolite profiles through changing soil temperature and years by effects on the soil environment (soil temperature and soil moisture) and root morphology (root length, specific root area, specific root length, and root diameter). In addition, we found that the root metabolism activity in warmed plots was lower than in control plots at the same soil temperature. Our data indicated that root metabolism in long-term warmed soil undergoes thermal acclimation, which may help match root metabolism with the required nutrient uptake and assimilation.
Keywords: Soil warming, root metabolism, primary metabolites, temperate forest.
How to cite: Liu, X., Heinzle, J., Tian, Y., Salas, E., Kwatcho-Kengdo, S., Borken, W., Schindlbacher, A., and Wanek, W.: Long-term soil warming changes the quantity but not the composition of primary metabolites of tree fine roots, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11752, https://doi.org/10.5194/egusphere-egu23-11752, 2023.
