降雨量增减对黄河三角洲滨海湿地土壤呼吸和芦苇光合特性的影响  

Effects of change in precipitation amount on soil respiration and photosynthetic characteristics of Phragmites australis in a coastal wetland in the Yellow River Delta,China

作　　者：陈亮[1] 孙宝玉[2] 韩广轩[2] 刘子亭[1] 贺文君[2] 王安东 吴立新 

机构地区：[1]聊城大学环境与规划学院,山东聊城252059 [2]中国科学院烟台海岸带研究所,中国科学院海岸带环境过程与生态修复重点实验室,山东烟台264003 [3]山东省黄河三角洲国家级自然保护区,山东东营257500

出　　处：《应用生态学报》2017年第9期2794-2804,共11页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(41671089);中国科学院科技服务网络计划项目(KFJ-EW-STS-127)资助~~

摘　　要：滨海湿地地下水位浅,淡咸水垂直交互作用明显,全球气候变化背景下降水变异改变其土壤表层水盐状况,从而影响植物光合作用与土壤呼吸.为探究降雨量变化对黄河三角洲滨海湿地土壤呼吸和光合特性的影响,采用固定式遮雨顶棚和雨水输送管道相结合的方法设置增减雨处理小区,于2015年生长季测定土壤呼吸和光合作用光响应曲线,同时连续测定土壤温度、土壤含水量、土壤含盐量等土壤环境因子.结果表明:根据土壤含水量波动情况可将生长季分为3个阶段:干旱期、湿润期、淹水期.不同土壤水分阶段,土壤呼吸和芦苇光合特性对降雨量增减的响应不同.在干旱期,增雨处理下土壤呼吸速率显著提高了31.8%,同时芦苇叶片气孔导度和光合能力显著增强;减雨处理下土壤呼吸速率降低41.1%,芦苇叶片气孔阻塞,光合能力降低.在湿润期,增雨和减雨处理使土壤呼吸速率及其温度敏感性指数(Q10)均出现下降,但二者未对芦苇各光合参数和净光合速率产生显著影响.在淹水期,增减雨处理未对土壤呼吸产生显著影响,但芦苇对淹水胁迫较为敏感,增减雨分别加重和降低了淹水对芦苇植株的伤害,光合速率由高到低为减雨>对照>增雨.The coastal wetland has shallow underground water level and is affected by the fresh water and salt water in vertical direction. The changes in precipitation amount can alter the conditions of soil water and salt, thus affecting soil respiration and plant photosynthesis. In order to clarify the effect of the change in precipitation amount on soil respiration and photosynthetic characteristics, we used rainout shelters and rainwater pipes to manipulate precipitation amount in the coastal wetland in the Yellow River Delta. Soil respiration and photosynthetic light response curve of Phragmites australis were measured during the growing season in 2015. Moreover, environmental factors including soil temperature, soil water content and soil salt content were measured simultaneously. The results showed that the whole growing season could be divided into three periods, drought period, wet period and flooding period, according to soil moisture condition. The effect of precipitation change on soil respiration and photosynthetic characteristics of P. australis was controlled by soil moisture condition. During the drought period, increased precipitation increased soil respiration significantly by 31.8% compared to the control. In addition, increased precipitation also increased stomatal conductance （gs） and photosynthetic capacity of plant leaf compared with those in the control, while decreased precipitation decreased soil respiration significantly by 41.1% compared with that in control. Meanwhile, decreased precipitation decreased the stomata obstruction and photosynthetic capacity of P. australis. During the wet period, soil respiration and the temperature sensitive of soil respiration （Q10） decreased in both increased and decreased precipitation treatments. Increase and decrease in precipitation amount both had no significant effect on the light response curve of P. australis. During the flooding period, increase and decrease in precipitation amount both had no significant effect on soil respiration, however, the

关 键 词：降雨变化 黄河三角洲 滨海湿地 土壤呼吸 光合作用 

分 类 号：Q948[生物学—植物学]