摘要
为了阐明酸雨对森林生态系统水相硫动态分布的影响,在1997~1999年以庐山植物园的针叶林和阔叶林为研究对象,对降雨、透冠水、干流水、渗漏水、径流水及硫通量进行了监测分析。结果表明,降水中SO2-4含量最高值出现在冬季,最低值在夏季;针叶林和阔叶林的透冠水、干流水和渗漏水中的SO2-4含量均高于降水,且透冠水和干流水均表现为春夏季较低、秋冬季较高,径流水变化与之相反;渗漏水针叶林冬季最高,阔叶林春季最高,其他三个季节差异不大;森林生态系统水相硫年际变化呈递增趋势,即1997年〈1998年〈1999年,1999年SO2-4浓度与1998和1997年之间差异达显著或极显著水平,而1997年和1998年差异不显著;针叶林的透冠水、干流水、渗漏水中的SO2-4含量均比阔叶林高,而径流水则比阔叶林低,其pH值变化与之相反。针叶林和阔叶林都能够较好的吸收大气沉降中的S,其固定量均高于降水中S的通量,故庐山森林生态系统目前仍是大气S沉降的汇,对酸沉降仍有缓冲作用,但针叶林由于高输入低输出,因此对S的固定能力更强。
Acid rain is one of the most serious environmental problems,and plays an important role in ecosystem function.In order to elucidate the water phase sulfur（S）in forest ecosystems and its response to acid rain,sulfate（SO2-4）concentrations in precipitation,throughfall water（TF）,stem-flow water（SF）,soil leakage water（SL）,and surface runoff water（SR）,as well as sulfur inputs and outputs of coniferous and broadleaf forest were analyzed in 1997-1999.Results show that SO2-4concentration of water phase has apparently seasonal changes.The maximum and the minimum value of SO2-4concentrations of rain water are found in samples collected in winter and summer,respectively.TF and SF water collected in spring and summer have higher SO2-4concentrations than those in autumn and winter,but SR water is on the contrary.The highest value of SO2-4concentration in SL water from coniferous forest is in the sample collected in winter,but for that from broadleaf forest is in spring.SO2-4concentrations in TF,SF and SL water are higher than that in rainwater.The water phase SO2-4of forest ecosystems shows an increasing trend in 1997-1999,following the order of 1997〈1998〈1999,with a significant difference between 1999 and 1998.Data of 1998 and 1997do not reach that significant level.SO2-4concentrations are different with forest types,and those in SL,SF and TF water in coniferous forest are higher than in broadleaf forest,but that in SR water in coniferous forest is lower than in broadleaf forest,in contrast with its pH changes.The coniferous and broadleaf can absorb sulfur from atmosphere,which is higher than the S flux by precipitation.The results suggest that it is a sulfur sink for atmospheric S deposition in Mt.Lushan forest ecosystem,which plays a buffer role for acid deposition,but coniferous forest has higher sulfur fixed ability than broadleaf forest.
出处
《地球与环境》
CAS
CSCD
2015年第1期8-13,共6页
Earth and Environment
关键词
庐山
酸雨
森林生态系统
水相硫
S通量
Mt.Lushan
acid rain
forest ecosystem
water phase sulfur
sulfur flux
