Growth and nitrogen use in Xanthium canadense grown in an open or in a dense stand.
Growth and nitrogen use in Xanthium canadense grown in an open or in a dense stand.
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DOI：
10.1111/j.1399-3054.2011.01563.x
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发表时间：
2012-04
影响因子：
6.4
通讯作者：
Ryoji Watari;Hisae Nagashima;T. Hirose
中科院分区：
文献类型：
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作者：
Ryoji Watari;Hisae Nagashima;T. Hirose
当植物单独生长时，枝条大量发育，而当植物生长在密集的林分中时，枝条发育较少。这种结构上的变化与干物质分配和氮素利用的变化有关。在这里，我们研究了植物生长和氮利用的性状受到不同的光气候在立场。一年生植物（Xanthium canadense）单独或在一个密集的立场。干物质的增长进行了分析的净同化率（NAR）和叶面积（LA）的产品。氮素利用效率（NUE）是氮素生产率（NP）和氮素平均停留时间（MRT）的乘积。这些增长变量被进一步分解为它们的组成部分。孤生植物保持较高的NAR，而在密集的立场，由于相互遮荫植物NAR下降。植物在密集的立场发展了一个更大的LA比叶面积比单性植物。孤生植株具有较高的氮素利用效率，这是由于较高的氮素利用效率。氮素营养效率的增加主要是由于氮素MRT的增加。光气候是不同的孤立和密集的立场植物，但他们采取了相当数量的氮，并利用它不同的响应给定的光气候。因此，NUE被证明是一个有用的工具，用于分析机制，导致不同的氮在植物生长中的使用。
Plants develop branches profusely when grown solitarily, while less so when grown in a dense stand. Such changes in architecture are associated with changes in dry mass allocation and nitrogen use. Here, we studied what traits in plant growth and nitrogen use were influenced by different light climates in the stand. Annual plants (Xanthium canadense) were grown solitarily or in a dense stand. Dry mass growth was analyzed as the product of the net assimilation rate (NAR) and leaf area (LA). Nitrogen use efficiency (NUE) was analyzed as the product of nitrogen productivity (NP) and the mean residence time (MRT) of nitrogen. These growth variables were further factorized into their components. Solitary plants maintained a high NAR, whereas plants in the dense stand decreased the NAR due to mutual shading. Plants in the dense stand developed a larger LA with a higher specific leaf area than solitary plants. Solitary plants had higher NUE due to higher NP. A temporal increase in NUE was attributed to the increase in MRT of nitrogen. Light climate was different between solitary and dense-stand plants, but they took up a comparable amount of nitrogen and used it differently in response to the given light climate. NUE was thus demonstrated to be a useful tool for analyzing the mechanism leading to different N use in plant growth.