Xingcuo lake,a closed one,is situated in eastern Tibetan Plateau.There are abundant snail shells Gy-raulus sibirica in its sediments.Here we display the determining results ofδ 13 C,δ 18 O in shell Gyraulus sibirica...Xingcuo lake,a closed one,is situated in eastern Tibetan Plateau.There are abundant snail shells Gy-raulus sibirica in its sediments.Here we display the determining results ofδ 13 C,δ 18 O in shell Gyraulus sibirica continuous-ly preserved in Xincuo Lake sediment s in the recent 50years.And by coupling the indexes ofδ 13 C,δ 18 O and instrumen-tal meteorological data in its basin to build relative function relation s among them,we probe quantitatively climatic sig-nals recorded in those indexes.The r esults show that there are remarkabl e relations betweenδ 13 C proxy and precipitation,δ 18 Oproxy and air temperature,of which correlative coefficient was 0.89an d 0.71,respectively.Besides,we also demon-strated that average variation betw eenδ 13 C proxy and precipitation(dδ 13 C /dP)was 0.027‰/mm and 1.64‰/℃forδ 18 O and air temperature(dδ 18 O /dT).展开更多
河流及水库等水生态系统中的溶解性无机碳(DIC)是全球碳循环与大气、陆地和海洋之间碳相互作用的重要组成部分.以澜沧江云南段上游天然河段及下游梯级水库群形成的连续体为研究对象,分析了河库连续体表层水体中水化学特征、溶解性无机...河流及水库等水生态系统中的溶解性无机碳(DIC)是全球碳循环与大气、陆地和海洋之间碳相互作用的重要组成部分.以澜沧江云南段上游天然河段及下游梯级水库群形成的连续体为研究对象,分析了河库连续体表层水体中水化学特征、溶解性无机碳浓度及其碳同位素时空分布特征.研究结果表明:河库连续体水体中溶解无机碳(DIC)及其同位素(δ13 C DIC)组成特征总体表现为:DIC浓度丰水期较低,枯水期较高,平均值分别为2.59±0.44和3.30±0.37 mmol/L;δ13 C DIC值丰水期偏负、枯水期偏正,平均值分别为-8.52‰±0.38‰和-6.95‰±0.53‰,与自然河流的季节变化特征相似.水体DIC来源主要包括土壤及水体有机质分解生成的CO 2、碳酸盐风化和水气界面CO 2的交换过程.澜沧江河库连续体中DIC浓度及δ13 C DIC组成的时空异质性特征与流域岩性、土壤生物地球化学过程以及微生物活动强度等均有较大关系.当前,澜沧江梯级水库群建库时间短,梯级联合运行下调度复杂,水文条件多变,梯级水库对河流重要生源要素——碳累积影响方面的“水库效应”还不明显.展开更多
文摘Xingcuo lake,a closed one,is situated in eastern Tibetan Plateau.There are abundant snail shells Gy-raulus sibirica in its sediments.Here we display the determining results ofδ 13 C,δ 18 O in shell Gyraulus sibirica continuous-ly preserved in Xincuo Lake sediment s in the recent 50years.And by coupling the indexes ofδ 13 C,δ 18 O and instrumen-tal meteorological data in its basin to build relative function relation s among them,we probe quantitatively climatic sig-nals recorded in those indexes.The r esults show that there are remarkabl e relations betweenδ 13 C proxy and precipitation,δ 18 Oproxy and air temperature,of which correlative coefficient was 0.89an d 0.71,respectively.Besides,we also demon-strated that average variation betw eenδ 13 C proxy and precipitation(dδ 13 C /dP)was 0.027‰/mm and 1.64‰/℃forδ 18 O and air temperature(dδ 18 O /dT).
文摘河流及水库等水生态系统中的溶解性无机碳(DIC)是全球碳循环与大气、陆地和海洋之间碳相互作用的重要组成部分.以澜沧江云南段上游天然河段及下游梯级水库群形成的连续体为研究对象,分析了河库连续体表层水体中水化学特征、溶解性无机碳浓度及其碳同位素时空分布特征.研究结果表明:河库连续体水体中溶解无机碳(DIC)及其同位素(δ13 C DIC)组成特征总体表现为:DIC浓度丰水期较低,枯水期较高,平均值分别为2.59±0.44和3.30±0.37 mmol/L;δ13 C DIC值丰水期偏负、枯水期偏正,平均值分别为-8.52‰±0.38‰和-6.95‰±0.53‰,与自然河流的季节变化特征相似.水体DIC来源主要包括土壤及水体有机质分解生成的CO 2、碳酸盐风化和水气界面CO 2的交换过程.澜沧江河库连续体中DIC浓度及δ13 C DIC组成的时空异质性特征与流域岩性、土壤生物地球化学过程以及微生物活动强度等均有较大关系.当前,澜沧江梯级水库群建库时间短,梯级联合运行下调度复杂,水文条件多变,梯级水库对河流重要生源要素——碳累积影响方面的“水库效应”还不明显.
