期刊
JOURNAL OF EXPERIMENTAL BOTANY
卷 61, 期 13, 页码 3735-3748出版社
OXFORD UNIV PRESS
DOI: 10.1093/jxb/erq183
关键词
Carbon isotope ratio; N:P ratio; nutrient supply; transpiration; tropical tree; water-use efficiency
资金
- Social Sciences and Humanities Research Council of Canada
- Smithsonian Tropical Research Institute
- Australian Postdoctoral Fellowship
- Australian Research Council [DP0771427]
- Australian Research Council [DP0771427] Funding Source: Australian Research Council
It is commonly assumed that the nitrogen to phosphorus (N:P) ratio of a terrestrial plant reflects the relative availability of N and P in the soil in which the plant grows. Here, this was assessed for a tropical pioneer tree, Ficus insipida. Seedlings were grown in sand and irrigated with nutrient solutions containing N:P ratios ranging from < 1 to > 100. The experimental design further allowed investigation of physiological responses to N and P availability. Homeostatic control over N:P ratios was stronger in leaves than in stems or roots, suggesting that N:P ratios of stems and roots are more sensitive indicators of the relative availability of N and P at a site than N:P ratios of leaves. The leaf N:P ratio at which the largest plant dry mass and highest photosynthetic rates were achieved was similar to 11, whereas the corresponding whole-plant N:P ratio was similar to 6. Plant P concentration varied as a function of transpiration rate at constant nutrient solution P concentration, possibly due to transpiration-induced variation in the mass flow of P to root surfaces. The transpiration rate varied in response to nutrient solution N concentration, but not to nutrient solution P concentration, demonstrating nutritional control over transpiration by N but not P. Water-use efficiency varied as a function of N availability, but not as a function of P availability.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据