【作者】 吕东珂；

【导师】 贾竞波； 于洪贤；

【作者基本信息】 东北林业大学 ， 野生动植物保护与利用， 2013， 博士

【摘要】 本研究从2008-2010年利用静态箱—气相色谱法对我国北方泥炭型水库生态系统水-气界面CO2通量进行全面观测。实验选取哈尔滨周边泥河和西泉眼两座典型的东北大型水库为主要研究对象。通过对水库春、夏、秋三季(平均200天)无冰期水-气界而CO2通量进行测定以研究其变化特征,对影响CO2通量的环境因子进行分析,重点讨论了水生植物对CO2通量的影响。由于水库每天进行渔业捕捞作业,鱼类的数量及其分布很难定量测定,所以本研究没有讨论水生动物对CO2通量的影响,在此特别说明。通过大量的数据分析,我们发现：(1)水库水-气界面C02通量时间变化规律明显通过对泥河水库和西泉眼水库三季(春、夏、秋季)水—气界面CO2通量变化的研究发现,水库生态系统总体上为大气CO2的源。CO2通量时间变化明显。从季节角度看,泥河水库基本变化趋势为：夏季756.42±54.58(mg m-2d-1)>春季714.16±83.45(mg m-2d-1)>秋季600.67±77.14(mg m-2d-1)。西泉眼水库与泥河水库略有不同,其变化规律为春季787.42±43.03(mg m-2d-1)>秋季409.24±13.64(mg m-2d-1)>夏季255.21±28.2(mg m-2d-1)。从昼夜角度看,西泉眼水库的昼夜变化与泥河水库相似,即水库的CO2通量日间小于夜间。尤其是6、7月份非常明显,昼夜间差额比高达121%。一般CO2通量的极小值出现在午后13：00,CO2通量的极大值出现在21：00或1：00左右。(2)水库水-气界面CO2通量存在空间异质性特征通过分析,我们发现水库CO2通量存在一定的空间异质性,泥河水库各研究点CO2通量大小依次为出水口>库心区>入水口。西泉眼水库各试验点的CO2通量大小依次为A>C>D>B。水库水位和消落带的变化以及水生植物的种类和分布成为影响CO2通量空间变化的主要因素。(3)水库水-气界面CO2通量的影响因子复杂水-气界面CO2通量变化的涉及影响因子较多,主要分为三大类,首先是生物因子主要指水生植物对碳通量的影响,通过叶绿素与碳通量的负相关性可以得到有效的印证。二是气候条件因子：包括风速、温度和天气情况,其中,温度对CO2通量的影响最为显著,呈明显的负相关性,风速与碳通量呈正相关。三是水体理化因子：包括DOC、水位、碱度、TP、TN和pH等；(4)北方水库水-气界面CO2通量的估算及对比本文对泥河水库和西泉眼水库CO2通量年排放量进行估算,二者全年碳排放量分别为1.01Gt a-1和1.08Gt a-1(G=1×109g),相差不大。通过对西泉眼水库和泥河水库碳通量的细节对比发现,水库的理化特性、地理位置、营养化水平和水生植物的类型等因子会对水库的CO2通量造成影响。通过与不同纬度、地区水库生态系统碳通量研究结果对比发现,北方泥炭型水库C02总体排放量并没有想像中的高,其排放量较高寒地区以及贫营养型水体要高,但是明显低于热带及亚热带水体碳排放水平,两个水库的通量值接近于湖泊生态系统C02通量。(5)对水库生态系统温室气体减排措施的建议通过研究我们明确了水库CO2通量的排放特征及影响水库CO2通量的主要因了,针对研究地水库的情况提出以下建议：①加强对上游及库区水质的控制；②优化水库植被的种类和结构；③重视水库渔业碳汇的作用。更多还原

【Abstract】 The static chamber/gas chromatography was used to conduct a comprehensive observation on CO2flux across water-air interface in northern peat-type reservoir ecosystem. Our research chose two large reservoirs Nihe and Xiquanyan as the main subject in Harbin, Heilongjiang province. According to the observation conducing in ice-free season (spring, summer, autumn) with average200days, we studied the spatial and temporal variation of CO2flux and discussed deeply on the environmental factors affecting CO2flux. We hope the results will give some data support for the regular research of CO2flux in reservoir ecosystem and its contribution to global climate change.By a large number of data analysis, we found that:(1) The diurnal variation of CO2flux across water-air interface in reservoirs is obviousAccording to the research, reservoir ecosystem was overall the source of atmospheric CO2. Diurnal variation of CO2flux is obvious. From seasonal perspective, the basic trend of Nihe Reservoir was:Summer756.42±54.58(mg m-2d-1)> Spring714.16±83.45(mg m-2d-1)> autumn600.67±77.14(mg m-2d-1). With a slightly difference the Xiquanyan Reservoir’trend was:Spring787.42±43.03(mg m-2d-1)> autumn409.24±13.64(mg m-2d-1)> Summer255.21±28.2(mg m-2d-1). While from the perspective of diurnal variation, the two reservoirs were similar:the CO2flux of day was less than that of night. Especially in June and July the difference was obvious with high rate of121%between day and night. The minimum value of CO2flux generally showed up at13:00in the afternoon, and maxima value appeared at21:00or1:00.(2) The feature of spatial heterogeneity was found in CO2flux across water-air interface in reservoirs.According to analysis, we found that there was certain spatial heterogeneity of CO2flux in the reservoirs. The CO2flux of sampling spots in Nihe was the water outlet> reservoir center> water inlet successively. The CO2flux of Xiquanyan was A>C>D> B. The main factors affecting the spatial variation of CO2flux were the change of reservoir level and fluctuating zone, and distribution of aquatic plant and species composition, respectively.(3) The factors impact CO2flux across water-air interface of the reservoir is complexCO2fluxes across water-air interface involving more impact factor which is divided into three categories,①climatic condition factors including wind speed, temperature and weather conditions, in which the influence of temperature on CO2flux is the most notable with significant negative correlation. It was positively correlated between wind speed and carbon flux.②water physical and chemical factors including DOC, water level, alkalinity, TP, TN and pH, etc.③biological factors mainly refers to the impact of aquatic plants on carbon fluxes, the negative correlation between chlorophyll and carbon fluxes can be effective confirmed. Moreover, impact factors on temporal and spatial variations of carbon flux were different.(4) CO2flux estimate of peat-type reservoirs and comparison with different areasThe estimate was made on CO2flux emissions from the two reservoirs, Nihe and Xiquanyan. The result showed that annual carbon emissions of two reservoirs was similar with value of1.01Gt a-1and1.08Gt a-1(G=1×109g), respectively. By contrast to the details of the carbon fluxes of two reservoirs, we found that physicochemical characteristics of the reservoir, location, water eutrophication and type of aquatic plants were important factors impacting CO2fluxes. Comparing with the results of reservoirs from different latitudes and regions, total CO2emissions of northern peat-type reservoirs was not significant as some scholars expected. It was higher than the ones in cold areas and oligotrophic water. But significantly lower than the ones in tropical and subtropical areas. Accually, the CO2emissions of two reservoirs were close to nature lakes.(5) Suggestions for reducing emissions of the greenhouse gas from reservoir ecosystem①strengthen the control of water quality from upstream of reservoir;②optimize the type and structure of the vegetation in the reservoir;③values the importance role of fisheries carbon sinks in reservoir.更多还原