Abstract: The distribution of selenium (Se) contents in surface soil are relatively nonuniformed in China. The region with poor Se in soil, so called Se-deficient soil belt, stretches from Northeast China to Southwest China. The mechanisms for Se distributions in Chinese soil, especially the formation of Se-deficient soil belt, are unclear. This review speculated that Se deposition associated with the East Asian monsoon and Se volatilization driven by microorganisms were key factors controlling Se distributions in surface soils in China. Wet deposition associated with the East Asian summer monsoon was responsible for dominant Se inputs into surface soils in Southeast China, and dry deposition associated with the East Asian winter monsoon was responsible for Se accumulation in surface soils in Northwest China. In Central China Se volatilization offset its precipitation, which cause negligible net Se input in surface soils. Se levels in most Chinese surface soil would be decreased in the future under climate change.

Key words: soil selenium distribution, selenium deficient belt, selenium precipitation, selenium volatilization, monsoon

摘要： 我国土壤硒含量分布严重不均，从东北到西南地区存在一条典型的土壤低硒带，然而该低硒带的成因至今仍不明确。基于硒干湿沉降和挥发的机理，亚洲季风造成的硒沉降和微生物驱动的硒挥发被认为是形成我国低硒带的主要驱动力。其中，夏季季风引起的湿沉降是东南地区富硒的主要原因，而冬季季风引起的干沉降是西北地区富硒的主要原因。中部地区因为硒挥发与沉降量相当，土壤中硒净积累很少，形成了低硒带。而且在全球气候变化的影响下，我国土壤中的硒含量将会呈现下降的趋势。

关键词: 土壤硒分布, 低硒带, 硒沉降, 硒挥发, 季风