Soil base saturation affects root growth of European beech seedlings§ |
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Authors: | Anika K Richter Yasuhiro Hirano Jörg Luster Emmanuel Frossard Ivano Brunner |
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Institution: | 1. Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Zürcherstra?e 111, 8903 Birmensdorf, Switzerland;2. Earth Environmental Systems, Graduate School of Environmental Studies, Nagoya University, Furo‐cho, Chikusa, Nagoya 464–8601, Japan;3. Institute of Plant Science, ETH Zürich, Eschikon 33, 8315 Lindau, Switzerland |
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Abstract: | To assess the potential effects of Al toxicity on the roots of young European beech (Fagus sylvatica L.), seeds were sown in soil monoliths taken from the Ah and B horizons of forest soils with very low base saturation (BS) and placed in the greenhouse. The Ah horizons offered a larger supply of exchangeable cation nutrients than the B horizons. After 8 weeks of growth under optimal moisture conditions, the seedlings were further grown for 14 d under drought conditions. Root‐growth dynamics were observed in rhizoboxes containing soils from the Ah and B horizons. The concentrations of Al3+, base cations, and nitrate in the soil solution and element concentrations in the root tissue were compared with above‐ and belowground growth parameters and root physiological parameters. There was no strong evidence that seedling roots suffered from high soil‐solution Al3+ concentrations. Within the tested range of BS (1.2%–6.5%) our results indicated that root physiological parameters such as O2 consumption decreased and callose concentration increased in soils with a BS < 3%. In contrast to the B horizons, seedlings in the Ah horizons had higher relative shoot‐growth rates, specific root lengths, and lengths and branching increments, but a lower root‐to‐shoot ratio and root‐branching frequency. In conclusion, these differences in growth patterns were most likely due to differences in nutrient availability and to the drought application and not attributable to differences in Al3+ concentrations in the soil solution. |
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Keywords: | aluminium toxicity Ca : Al molar ratio callose O2 consumption root morphology root‐to‐shoot ratio |
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