Beijing Key Laboratory of Farmland Soil Pollution Prevention-control and Remediation, Department of Environmental Sciences and Engineering, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
Institute of Desertification Studies, Chinese Academy of Forestry, Beijing, 100091, China.
Environ Pollut. 2018 Dec;243(Pt A):404-409. doi: 10.1016/j.envpol.2018.09.010. Epub 2018 Sep 5.
How terrestrial ecosystem responds to global warming has received wide attention. Plant stoichiometry has the potential to reflect ecosystem responses to climate change, thus, investigating the variations in plant stoichiometry with temperature is important and necessary for revealing the responses of terrestrial ecosystem to global warming. Although many studies had explored the relationships between plant N, P stoichiometry and temperature, previous field investigations did not eliminate the interference of precipitation effect with these observed relationships. To minimize the effect of precipitation on leaf N, P stoichiometry, this investigation was conducted across a temperature gradient over broad geographical scale along the 400 mm isohyet, which extends about 6000 km in China. This study showed that leaf N did not vary, whereas leaf P decreased and leaf N:P ratio increased with increasing mean annual temperature (MAT). The responses of leaf N and P stoichiometry to MAT observed in this study might be general patterns; because they were almost ubiquitous across functional groups, genera and species examined, and moreover, they were independent of vegetation and soil type. It could be inferred from this study that global warming in future will have no effect on leaf N, but reduce leaf P and increase leaf N:P ratio. Stable leaf N and varied leaf P with changing MAT suggested that leaf N and P decoupled with changing temperature.
陆地生态系统对全球变暖的响应受到了广泛关注。植物化学计量学有可能反映生态系统对气候变化的响应，因此，研究植物化学计量学随温度的变化对于揭示陆地生态系统对全球变暖的响应是重要且必要的。尽管许多研究已经探讨了植物氮、磷化学计量与温度之间的关系，但先前的实地调查并没有消除降水对这些观察到的关系的干扰。为了最小化降水对叶片氮、磷化学计量的影响，本研究在沿中国约 6000 公里长的 400 毫米等雨量线的广阔地理范围内，沿着温度梯度进行了调查。研究表明，叶片氮没有变化，而叶片磷减少，叶片氮磷比随着年平均温度（MAT）的升高而增加。本研究中观察到的叶片氮和磷化学计量对 MAT 的响应可能是普遍模式；因为它们几乎普遍存在于所研究的功能群、属和种中，而且它们与植被和土壤类型无关。从本研究中可以推断，未来的全球变暖将不会影响叶片氮，但会减少叶片磷并增加叶片氮磷比。随着 MAT 的变化，叶片氮稳定而叶片磷变化表明，叶片氮和磷随温度的变化而解耦。
