Deposition of long-range transported particulate matter on the needle surfaces of Japanese cypress (Chamaecyparis obtusa) grown in Nagasaki located in the western region of Japan
Deposition of long-range transported particulate matter on the needle surfaces of Japanese cypress (Chamaecyparis obtusa) grown in Nagasaki located in the western region of Japan
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DOI：
10.2480/agrmet.d-18-00016
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发表时间：
2019-01
影响因子：
1.3
通讯作者：
M. Yamaguchi;Sayaka Tsuji;Kasumi Ogata;Hayato Ide;Taketomo Matsushita;Naoto Murao
中科院分区：
文献类型：
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作者：
M. Yamaguchi;Sayaka Tsuji;Kasumi Ogata;Hayato Ide;Taketomo Matsushita;Naoto Murao
为研究日本林木叶表面长距离输送颗粒物(PM)的沉积特征，于2017年4月24日至10月30日对生长在日本西部长崎山区的成熟柏树针叶表面PM进行了定期采集。分析了颗粒物中金属元素的组成、浓度比以及铅同位素的比值。针叶表面金属元素(Na、Mg、Al、K、Ca、V、Cr、Mn、Fe、Ni、Cu、Zn、As、Pb)总量在夏季和秋季相对较低，但受亚洲大陆外流的影响，在春季大气中直径小于2.5μm的颗粒物浓度较高时，针叶表面金属元素总量较高。不太丰富的金属元素(铝、钒、镍、铜、锌、砷和铅)的数量的季节变化也表现出类似的趋势。铅量与锌量之比为0.4，接近中国PM的铅锌比值。颗粒物中的大部分铅同位素比值(铅/铅和铅/铅)与中国煤中观测到的值接近。因此，针上的铅可能来自中国的燃煤。铅的富集度(EF)在650~2270之间，且与铅/铅比值显著相关，表明富集系数大于650的组分可能来源于人为来源。铅的含量与镍、铜、锌、砷的含量呈显著正相关，表现为EFS>650。这些结果表明，铅、镍、铜、锌、砷等元素的远程迁移来源于中国的人为来源，并沉积在长崎生长的钝顶牡蛎的针叶上。
To characterize the deposition of long-range transported particulate matter (PM) on the foliar surface of Japanese forest trees, we periodically collected the PM deposited on the needle surface of mature Japanese cypress (Chamaecyparis obtusa) grown in the mountainous area of Nagasaki located in the western region of Japan from 24 April to 30 October, 2017. Metal element compositions and concentration ratios along with the ratios of Pb isotopes in the PM were analyzed. The total amount of metal elements (Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, As and Pb) on the needle surfaces was relatively low during summer and autumn but was high during the spring when there was high atmospheric concentration of PM with diameter less than 2.5 μm due to influence of outflow from Asian continent. The seasonal variations in the amounts of less-abundant metal elements (Al, V, Ni, Cu, Zn, As and Pb) exhibited similar trends. The Pb amount varied with Zn amount at a constant ratio of 0.4, which was close to the Pb /Zn ratio of PM in China. Most of the Pb isotope ratios (Pb / Pb and Pb / Pb) in the PM were close to those observed in the Chinese coal. Therefore, Pb on the needle could have originated from the coal combustion in China. The enrichment factor (EF) of Pb ranged from 650 to 2270, and was significantly correlated with the Pb / Pb ratios, suggesting that components having EFs of greater than 650 could have originated from anthropogenic source. The amount of Pb significantly correlated with that of Ni, Cu, Zn, and As, which showed EFs more than 650. These results indicate that the long-range transported PM, including Pb, Ni, Cu, Zn, and As, originated from the anthropogenic sources in China, and deposited on the needle of C. obtusa grown in Nagasaki.