Slow decomposition and limited nitrogen release by lower order roots in eight Chinese temperate and subtropical trees
Slow decomposition and limited nitrogen release by lower order roots in eight Chinese temperate and subtropical trees
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DOI：
10.1007/s11104-012-1290-8
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发表时间：
2013-02
期刊：
影响因子：
4.9
通讯作者：
Yanmei Xiong;Pingping Fan;S. Fu;H. Zeng;Dali Guo
中科院分区：
文献类型：
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作者：
Yanmei Xiong;Pingping Fan;S. Fu;H. Zeng;Dali Guo
最低分支级的根具有最高的死亡率，并且可能主要贡献于植物碳（C）和养分向土壤的转移。然而，这些根的分解模式和控制因素知之甚少。MethodsWe进行了为期两年的实地垃圾袋研究不同的根订单和叶凋落物在四个温带和四个亚热带treates.ResultsFive种表现出较慢的衰减率较低的（为了1-2）比高阶（为了3-5）根，所有物种表现出较慢的衰减率在较低的顺序根比叶凋落物。这些模式强烈相关的酸不溶部分在较低的比高阶根，根比落叶，但不相关的初始N浓度。凋落物N主要是在necroscitrant的形式和有限的N量被释放在研究期间，只有12%的根N和26%的落叶N被释放在2 years. Conclusions我们得出结论，低阶根的缓慢分解可能是一种常见的现象，主要是由他们的高酸不溶性馏分驱动。此外，凋落物N，特别是根N，在分解过程中保留，可能无法立即被植物吸收。
Background and aimsRoots of the lowest branch orders have the highest mortality rate, and may contribute predominately to plant carbon (C) and nutrient transfer into the soil. Yet patterns and controlling factors of the decomposition of these roots are poorly understood.MethodsWe conducted a two-year field litterbag study on different root orders and leaf litter in four temperate and four subtropical tree species.ResultsFive species showed slower decay rates in lower- (order 1–2) than higher-order (order 3–5) roots, and all species showed slower decay rates in lower-order roots than leaf litter. These patterns were strongly related to higher acid-insoluble fraction in lower- than higher-order roots, and in roots than in leaf litter, but were unrelated to initial N concentration. Litter N was predominantly in recalcitrant forms and limited amount of N was released during the study period;only 12 % of root N and 26 % of leaf litter N was released in 2 years.ConclusionsWe conclude that the slow decomposition of lower-order roots may be a common phenomenon and is mainly driven by their high acid-insoluble fraction. Moreover, litter N, especially root N, is retained during decomposition and may not be available for immediate plant uptake.