The responses of Scots pine seedlings to waterlogging in a fine-textured till soil

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• 作者：Tapani Repo ; Juha Heiskanen ; Marja-Liisa Sutinen ; Raimo Sutinen ; Tarja Lehto
• 关键词：Pinus sylvestris L. ; Photosystem II activity ; Reforestation ; Root morphology ; Soil water saturation
• 刊名：New Forests
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：48
• 期：1
• 页码：51-65
• 全文大小：
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Forestry;
• 出版者：Springer Netherlands
• ISSN：1573-5095
• 卷排序：48

文摘

Growth decline of Scots pine (Pinus sylvestris L.) on reforestation sites with fine-textured soils are suggested to be due to periodic soil wetness. In this study, Scots pine seedlings were exposed to waterlogging in fine-textured till soil in growth chambers. The treatments started 5 weeks after germination and lasted either for 3 or 8.5 weeks. Three weeks in water-saturated soil affected negatively the root length, root surface area, root volume, the number of root tips, the length of the longest root, root dry mass, the root to shoot ratio, needle water and nitrogen content, and the apoplastic electrical resistance of the stem. The changes by 3 weeks exposure were recoverable since most of the attributes returned to the level of controls when the oxygen content returned to a normoxic level. In contrast, detrimental, but not lethal, effects of water saturation were observed after exposure for 8.5 weeks. Additional effects of prolonged exposure were a decrease in the potential efficiency of photosystem II, the distribution of absorbed light energy between light reactions and the release as heat by chlorophyll fluorescence, and the chlorophyll content index of the needles. We conclude that prolonged water saturation of fine-textured soil is detrimental to the development of Scots pine seedlings which should be considered in practical forest regeneration.