Response of Ulmus americana seedlings to varying nitrogen and water status. 2 Water and nitrogen use efficiency in photosynthesis.
Response of Ulmus americana seedlings to varying nitrogen and water status. 2 Water and nitrogen use efficiency in photosynthesis.
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DOI：
10.1093/treephys/5.2.173
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发表时间：
1989-06
期刊：
影响因子：
4
通讯作者：
P. Reich;M. Walters;T. Tabone
中科院分区：
文献类型：
--
作者：
P. Reich;M. Walters;T. Tabone
美洲榆水分和氮素的光合利用。幼苗与每种资源的相对可利用性密切相关。在周期性的干燥周期中，水分利用效率随着黎明前水势从-0.5降至-2.0 MPa而增加。在干燥周期的后期阶段，气孔限制对总净光合限制的相对贡献似乎是最大的，而生物化学限制在低氮（N）可用性下生长的水分充足的植物中占主导地位。在不同的叶片水分状况下，高氮植株的光合水分利用效率（WUE）均高于低氮植株。光合氮利用效率（PNUE）总是在植物叶片氮含量低比植物叶片氮含量高，任何水平的水分状况。在氮素配施和黎明前水分状况下，PNUE与WUE呈显著负相关。
Photosynthetic utilization of water and nitrogen in Ulmus americana L. seedlings was tightly linked with the relative availability of each resource. During periodic drying cycles, water use efficiency increased as predawn water potential fell from -0.5 to -2.0 MPa. During the later stages of such drying cycles, the relative contribution of stomatal limitations to the total net photosynthetic limitation appeared to be at its greatest, whereas biochemical limitations were predominant in well-watered plants grown under low nitrogen (N) availability. For any level of leaf water status, water use efficiency of photosynthesis (WUE) was always greater in plants with high leaf N content than in plants with low leaf N content. Photosynthetic nitrogen use efficiency (PNUE) was always greater in plants with low leaf N content than in plants with high leaf N content, for any level of water status. In combined N treatments and predawn water status classes, there was a significant inverse relationship between PNUE and WUE.