摘要
在室内模拟闭光与光照条件,研究长江口滨岸潮滩沉积物-水界面的可溶性硅(SiO3-Si)与无机氮(TIN)通量的变化规律,探讨相关理化因素对其的影响.结果表明:在春夏秋季适合硅藻生长的季节,光照能促进硅藻生长与摄取硅,从而能降低SiO3-Si通量,冬季相反,且二者的效应都不太明显.光照能刺激底栖微生物将NH4+-N硝化为NOx-N,从而明显降低NH4+-N通量,且能明显升高NOx-N通量.通过相关分析及数学处理发现,光照影响SiO3-Si通量的温度临界值为20℃;盐度过高会减弱光照对NH4+-N通量的下降效应;温度过高会减弱光照对NOx-N通量的上升效应.采用趋势线斜率方法判定光照能降低上覆水中ρ(SiO3-Si)/c(TIN)值,光照可能会对底栖微生物群落的结构产生较大影响.
Indoor stimulation flux experiments were used to research the changes in dissolved silicon and inorganic nitrogen flux across the sediment-water interface under dark and light conditions,and the influence of relative physical and chemical factors on flux were discussed.The results showed that： in spring,summer and autumn conditions suitable for growth of diatom,light could stimulate the growth of diatom and accelerate the uptake of dissolved silicon,resulting in a decrease of（SiO3-Si） flux from sediment to overlying water,but in winter neither effect was obvious;and,light could stimulate benthic microorganisms to nitrify（NH4^＋-N） to（NOx-N）,resulting in a decrease of（NH4^＋-N） flux and an increase of（NOx-N） flux from sediment to overlying water.Correlation analysis and mathematics processing showed that： the critical temperature value for the positive/negative impact of light on（SiO3-Si） flux is about（20 ℃）;high salinity could weaken the negative impact of light on（NH4^＋-N） flux;and,high temperature could weaken the positive impact of light on（NOx-N） flux.Light was determined to decrease the value of（SiO3-Si/TIN） in overlying water by the method of trend slope;therefore, it probably had a large impact on the structure of the benthic microorganism population.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2009年第3期327-331,共5页
Research of Environmental Sciences
基金
国家自然科学基金项目(40611171,40730526)
