酸沉降影响下庐山森林生态系统土壤硫形态分布研究

近年来 ,因农业高产的养分平衡问题及因酸沉降污染问题硫的植物营养与生物地球化学研究日益活跃。至今已有较多研究者对农田和自然土壤中硫含量、形态分布及不同施肥条件和作物对它们的影响进行了研究1,2 ,12～ 16 ] 。酸沉降影响下森林土壤硫及其去向倍受关注。研究表明 ,在高度风化的土壤上的森林生态系统中ＳＯ4 2 - 处于积累状态17] ,而发育时间较短的土壤上的森林生态系统中ＳＯ4 2 - 则处于接近动态平衡的状态18,19] 。Ｃａｒｌｓｓｏｎ等2 0 ] 利用34Ｓ对挪威半岛森林土壤硫形态及其与酸沉降的关系进行了研究 ,认为有机硫和吸附…

Sulfur Fractions in Typic Udalfs in Forest Ecosystem in Mt. Lushan as Affected by Acid Deposition.

Acid deposition has been a severe environmental pollution problem in Mt. Lushan since early 1980, Soil acidification trends have been resultantly obvious. Pedons of the Typic Udalfs both under deciduous and coniferous forest with and without root-growing effects were sampled. Soil sulfur was fractionated by selective extraction methods and the sulfur in solutions was determined by BaSO4 turbidimetry. The results showed the total S in surface layers amounted to 400-800mg*kg-1, indicating a high net accumulation of S under impacts of the acid deposition. The sulfur in the soils were predominated by adsorbed sulfur(160.0±72.1mg*kg-1) and organic sulfur(123.3±142.9 mg*kg-1), with the former accumulating to deep profile and the latter in surface 0-30 cm depth. Under deciduous soil sulfur accumulated to deep profile. Adsorbed sulfur under coniferous was higher (152.72 mg*kg-1) than which under deciduous (121.85 mg*kg-1), while the latter contained more water sulfur, indicating sulfur under deciduous inclined to move. Soils with root-growing effects contained more total sulfur (351.15 mg*kg-1) than soil without root-growing effects (300.50 mg*kg-1), high organic sulfur accumulated in soils in root-growing depth, but no significant profile difference under deciduous. Therefore, the sulfur transform was involved in accumulation of sulfur affected by acid deposition.