Moss as an indicator of transboundary atmospheric nitrogen pollution in an alpine ecosystem
Moss as an indicator of transboundary atmospheric nitrogen pollution in an alpine ecosystem
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DOI：
10.1016/j.atmosenv.2019.04.005
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发表时间：
2019-07
影响因子：
5
通讯作者：
Yoshitaka Oishi
中科院分区：
文献类型：
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作者：
Yoshitaka Oishi
大气氮污染增加会影响高山生态系统中氮的沉积。苔藓通常在这些生态系统中占据主导地位，它们的N含量(%N)和稳定同位素比(δ15N)被用作大气N沉降的指示器。在这里，我们使用一种单一的苔藓物种(华丽苔藓)作为日本山区大气氮沉降的生物指示器。从海拔1800~2800 m的所有坡向(东、西、南、北)的38个地点采集了苔藓。利用基于层次贝叶斯框架的线性模型分析了苔藓N变量(%N和δ15N)与环境条件(海拔和坡向)之间的相关性。在所构建的模型中，%N在所有坡度方面都与海拔呈显著或微弱的负相关。相反，δ15N与海拔高度呈显著正相关，且在西部高山坡地最高。当使用δ15N作为氮源的标志时，西坡高山苔藓中的氮似乎受到通过颗粒物(PM)从亚洲大陆带到日本的跨界N污染物的影响，这些污染物是由盛行的西风和西北季风带来的。然而，由于苔藓氮还受到其他因素的影响，如不同的氮化学形态、蓝藻的固定氮以及大气氮的季节差异，进一步的研究应直接将苔藓氮与大气氮沉降进行比较，以阐明跨界氮污染物对苔藓氮的影响。
Increased atmospheric nitrogen (N) pollution affects N deposition in alpine ecosystems. Moss often dominates these ecosystems and their N content (%N) and stable isotope ratio (δ15N) are used as indicators of atmospheric N deposition. Here, we used a single moss species (Hylocomium splendens) as a bioindicator of atmospheric N deposition in the mountainous areas of Japan. The moss was collected from 38 sites on all slope aspects (east, west, south, and north) ranging from 1800 to 2800 m in altitude. The correlation between moss N variables (%N and δ15N) and environmental conditions (altitude and slope aspects) was analyzed using linear models based on a hierarchical Bayesian framework. In the constructed models, %N showed a significant or weak negative correlation with altitude on all slope aspects. In contrast, δ15N was significantly and positively correlated with altitude, with high values on the western alpine slopes. When using δ15N as a marker of N sources, N in alpine moss on the west slope seemed to be influenced by transboundary N pollutants through particulate matter (PM), which is brought to Japan from mainland Asia by prevailing westerly winds and northwest monsoons. However, as moss N is also affected by other factors, such as different N chemical forms, fixed N from cyanobacteria, and seasonal differences in atmospheric N, further research should directly compare moss N with atmospheric N deposition to elucidate the influence of transboundary N pollutants on moss N.