Key Laboratory of Hangzhou City for Ecosystem Protection and Restoration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China.
Sci Rep. 2017 Feb 24;7:43018. doi: 10.1038/srep43018.
Geographic patterns in leaf stoichiometry reflect plant adaptations to environments. Leaf stoichiometry variations along environmental gradients have been extensively studied among terrestrial plants, but little has been known about intraspecific leaf stoichiometry, especially for wetland plants. Here we analyzed the dataset of leaf N and P of a cosmopolitan wetland species, Phragmites australis, and environmental (geographic, climate and soil) variables from literature and field investigation in natural wetlands distributed in three climatic regions (subtropical, temperate and highland) across China. We found no clear geographic patterns in leaf nutrients of P. australis across China, except for leaf N:P ratio increasing with altitude. Leaf N and N:P decreased with mean annual temperature (MAT), and leaf N and P were closely related to soil pH, C:N ratio and available P. Redundancy analysis showed that climate and soil variables explained 62.1% of total variation in leaf N, P and N:P. Furthermore, leaf N in temperate region and leaf P in subtropical region increased with soil available P, while leaf N:P in subtropical region decreased with soil pH. These patterns in P. australis different from terrestrial plants might imply that changes in climate and soil properties can exert divergent effects on wetland and terrestrial ecosystems.
地理格局反映了植物对环境的适应。沿环境梯度的叶片化学计量变异已在陆生植物中得到广泛研究，但对种内叶片化学计量的了解甚少，特别是对湿地植物。本研究分析了来自文献的广泛分布于中国三个气候区（亚热带、温带和高原）的天然湿地中，一种世界性湿地植物芦苇的叶片氮（N）和磷（P）数据集，以及地理（气候和土壤）变量。我们发现，除了叶片 N：P 比值随海拔升高而增加外，芦苇的叶片养分在中国没有明显的地理格局。叶片 N 和 N：P 随年平均温度（MAT）降低，叶片 N 和 P 与土壤 pH、C：N 比和有效磷密切相关。冗余分析表明，气候和土壤变量解释了叶片 N、P 和 N：P 总变异的 62.1%。此外，温带地区的叶片 N 和亚热带地区的叶片 P 随土壤有效磷增加而增加，而亚热带地区的叶片 N：P 随土壤 pH 降低而降低。这些芦苇在不同地区的格局与陆生植物不同，这可能意味着气候和土壤特性的变化会对湿地和陆地生态系统产生不同的影响。
