模拟盐水入侵及Fe(III)浓度增强对河口感潮淡水沼泽湿地土壤反硝化速率及理化特征的影响

Effects of simulated saltwater intrusion and Fe(III) increase on denitrification rate and soil environmental properties in tidal freshwater marsh of the Min River estuary

以闽江河口塔礁洲感潮淡水野慈姑(Sagittaria trifolia Linn.)湿地为研究对象,于2016年2、4、7和9月每月均在连续2个小潮日内向研究样地施加人造海水和Fe(OH)_3溶液,研究短期的盐水入侵及Fe(III)浓度增强对河口感潮淡水湿地土壤反硝化速率及理化特征的影响.结果表明,短期的盐水入侵、Fe(III)浓度增强对河口感潮淡水沼泽湿地土壤反硝化速率的影响不显著,然而,盐水和Fe(III)共同施加会显著提高湿地土壤反硝化速率,与对照(CK)相比,盐水和Fe(III)共同施加可使土壤反硝化速率提高270.9%.盐水入侵、盐水和Fe(III)共同施加均可显著提高湿地土壤、间隙水的电导率及Cl^-、SO_4^(2-)的含量;Fe(III)浓度增强可显著降低土壤和间隙水pH值,同时显著提高土壤三价铁含量.

The effects of short-term saltwater intrusion and Fe(Ⅲ)amendament on the soil denitrification rates and soil environmental parameters of the tidal freshwater marsh dominated by Sagittaria trifolia in the Tajiaozhou of the Min River estuary were determined by the in situ additions of artificial sea salt and Fe(Ⅲ)solution in continuous two neap tide days in February,April,July and September 2016.The results showed that the simulated short-term saltwater intrusion coupled with Fe(Ⅲ)input significantly promoted the soil denitrification rates,and compared with the control treatments,the denitrificatiou rate increased 270.9%,however,the soil denitrification rates did not significantly changed with the treatments of saltwater intrusion,and Fe(Ⅲ)increase alone.The treatments of saltwater intrusion,and saltwater intrusion coupled with Fe(Ⅲ)input significantly increased conductivity,the pore water SO4^2- and Cl^- concentrations;and the Fe(Ⅲ)amendament significantly decreased pH,and significantly increased soil Fe(Ⅲ)contents.