基于15N同位素配对技术和室内模拟实验方法,分析了三门湾健跳港牡蛎养殖区沉积物反硝化速率的时空变化及其关键影响因子.结果表明,在牡蛎养殖区(oyster culture area,OA)和对照区(control area,CA),夏季沉积物反硝化速率均显著高于冬季(P＜0.05).在夏季,OA区[(2 227.70±816.00)μmol·m-2 ·h-1]沉积物反硝化速率显著高于CA区[(834.68±55.52)μmol·m-2·h-1](P＜0.01);在冬季,OA区[(266.95±49.03)μmol·m-2.h-1]和 CA 区[(221.00±62.09)μmol·m-2·h-1]沉积物反硝化速率无显著差异(P＞0.05).夏、冬季,水体温度、盐度、溶解氧和沉积物S2-均会对沉积物的反硝化作用产生显著影响.其中,温度、S2-与沉积物反硝化速率呈显著正相关关系(P＜0.05);盐度和溶解氧则与沉积物反硝化速率呈显著负相关关系(P＜0.05).而沉积物总有机碳、NO2--N仅在夏季会显著影响沉积物反硝化作用,两者与沉积物反硝化速率均呈显著正相关关系(P＜0.05).研究结果可为牡蛎的除氮功能评价提供新的理论依据,也可为双壳贝类在氮生物地球化学中的作用研究提供理论支持.
Spatio-temporal variation of sediment denitrification rate in oyster culture area of Jiantiao Habor of Sanmen Bay and its regulators
In this study,we systematically investigated the spatial and temporal variation of sediment denitrification rate and its key regulators in oyster farm of Jiantiao Habor of Sanmen Bay through isotope pairing technique and lab-simulated experiments.As the results showed,in both oyster culture area and control area,sediment denitrification rates in summer were higher than those in winter(P＜0.05).In summer,sediment denitrification rate in oyster culture area[(2 227.70±816.00)μmol·m-2·h-1]was remarkably higher than that in control area[(834.68±55.52)μmol·m-2·h-1](P＜0.01),whereas,sediment denitrification rates did not differ significantly between oyster culture area[(266.95±49.03)μmol ·m-2·h-1]and control area[(221.00±62.09)μmol·m-2·h-1](P＞0.05).In summer and winter,it was found that the key regulators significantly affecting sediment denitrification were abiotic factors of overlying water(temperature,salinity,dissolved oxygen content)and sediment(sulfide ion content),moreover,correlations of temperature and sulfide ion content with sediment denitrification rate were positive(P＜0.05),and correlations of salinity and oxygen content with denitrification rate of sediment were negative(P＜0.05).Nevertheless,sediment(total organic carbon content,nitrite content)remarkably affected sediment denitrification only in summer,and correlations between sediment(total organic carbon content,nitrite content)and sediment denitrification rate were positive(P＜0.05).As a whole,the influence of sediment environmental physicochemical factors on sediment denitrification rate was stronger in summer than in winter.The results can supply new theoretical basis for the evaluation of nitrogen removel function of oyster,and provide theoretical support for study on the role of bivalve in nitrogen biogeochemistry.
万方数据
维普
