Using the Guancun River, an underground stream-fed river, in Rong＇an County of Guangxi, China as a case study, the daily biochemical cycle was examined in this paper based on the data collected a weeklong via high re...Using the Guancun River, an underground stream-fed river, in Rong＇an County of Guangxi, China as a case study, the daily biochemical cycle was examined in this paper based on the data collected a weeklong via high resolution data logger monitoring and high-frequency sampling. Furthermore, the loss of inorganic carbon along its flow path was estimated. Results show that chemical components of the groundwater input are quite stable, showing little change extent; while all of the chemical parameters from two downstream monitoring stations show diel variation over the monitoring period, suggesting that plant activity in the river has a strong influence on water chemistry of the river. The comparison of the input fluxes from the groundwater with the output fluxes of HCO~ estimated at the downstream monitoring station during the high-frequency sampling period shows a strong decrease of HCO~, indicating that the river is losing inorganic carbon along its flow path. The loss is estimated to be about 1,152 mmol/day/m of HCO~ which represent about 94.9 kg/day of inorganic carbon along the 1,350 m section of the Guancun River. It means that HCO~ entering the river from karst underground stream was either consumed by plants or trapped in the authigenic calcite and thus constitutes a natural sink of carbon for the Guancun karst system.展开更多
Using the summer (June to August) monthly mean data of the National Centers for Environmental Predictions (NCEP) - National Center for Atmospheric Research (NCAR) reanalysis from 1980 to 1997, atmospheric heat sources...Using the summer (June to August) monthly mean data of the National Centers for Environmental Predictions (NCEP) - National Center for Atmospheric Research (NCAR) reanalysis from 1980 to 1997, atmospheric heat sources and moisture sinks are calculated. Anomalous circulation and the vertically integrated heat source with the vertical integrated moisture sink and outgoing longwave radiation (OLR) flux are examined based upon monthly composites for 16 great wet-spells and 8 great dry-spells over the middle-lower reaches of the Yangtze River. The wind anomaly exhibits prominent differences between the great wet-spell and the great dry-spell over the Yangtze River Valley. For the great wet-spell, the anomalous southerly from the Bay of Bengal and the South China Sea and the anomalous northerly over North China enhanced low-level convergence toward a narrow latitudinal belt area (the middle-lower reaches of the Yangtze River). The southerly anomaly is connected with an anticyclonic anomalous circulation system centered at 22 degreesN, 140 degreesE and the northerly anomaly is associated with a cyclonic anomalous circulation system centered at the Japan Sea. In the upper level, the anomalous northwesterly between an anticyclonic anomalous system with the center at 23 degreesN, 105 degreesE and a cyclonic anomalous system with the center at Korea diverged over the middle-lower reaches of the Yangtze River. On the contrary, for the great dry-spell, the anomalous northerly over South China and the anomalous southerly over North China diverged from the Yangtze River Valley in the low level. The former formed in the western part of a cyclonic anomalous system centered at 23 degreesN, 135 degreesE. The latter was located in the western ridge of an anticyclonic anomalous system in the northwestern Pacific. The upper troposphere showed easterly anomaly that converged over the middle-lower reaches of the Yangtze River. A cyclonic anomalous system in South China and an anticyclonic system centered in the Japan Sea enhanced the easterly. Large atmospheric heat source anomalies of opposite signs existed over the western Pacific - the South China Sea, with negative in the great wet-spell and positive in the great dry-spell. The analysis of heat source also revealed positive anomalous heat sources during the great wet-spell and negative anomalous heat sources during the great dry-spell over the Yangtze River valley. The changes of the moisture sink and OLR were correspondingly altered, implying the change of heat source anomaly is due to the latent heat releasing of convective activity. Over the southeastern Tibetan Plateau- the Bay of Bengal, the analysis of heat source shows positive anomalous heat sources during the great wet-spell and negative anomalous heat sources during the great dry-spell because of latent heating change. The change of divergent wind coexisted with the change of heat source. In the great wet-spell, southerly divergent wind anomaly in the low level and northerly divergent wind anomaly in high-level are seen over South China. These divergent wind anomalies are helpful to the low-level convergence anomaly and high-level divergence anomaly over the Yangtze River valley. The low-level northerly divergent wind anomaly and high-level southerly divergent wind anomaly over South China reduced the low-level convergence and high-level divergence over the Yangtze River valley during the great dry-spell.展开更多
中国西南部的金沙江干热河谷地带是生态脆弱区,其新造林碳汇是林业碳汇的重要组成部分。但目前对干热河谷地区森林碳汇能力的研究尚不充分,新造林的碳汇能力尚不明确。以2014-2021年宾川县新造人工林为典型研究对象,通过陆地生态系统生...中国西南部的金沙江干热河谷地带是生态脆弱区,其新造林碳汇是林业碳汇的重要组成部分。但目前对干热河谷地区森林碳汇能力的研究尚不充分,新造林的碳汇能力尚不明确。以2014-2021年宾川县新造人工林为典型研究对象,通过陆地生态系统生产力模拟(BEPS)模型,研究金沙江干热河谷地带的碳汇能力特征。结果表明:(1)宾川新造人工林碳汇能力在2014-2016年逐渐升高,随后稳定,年均净生态系统生产力(net ecosystem productivity,NEP)为247.82±140.59 g C/(m^(2)/a);(2)宾川县人工林每年碳汇量自2014年起逐年增加,从2014年的2398.2 t C/a提升到2021年24028.1 t C/a;(3)宾川县人新造工林生态系统整体碳汇能力呈现东部和北部高,西南部低的分布趋势,各乡镇年均NEP在167.44~349.85 g C/(m^(2)/a),碳汇量在468.42~3832.72 t C/a;(4)不同造林类型的碳汇能力存在显著差异,阔叶灌木混合林的NEP显著高于其他类型林地。探究了宾川县新造工林的碳汇能力特征,研究结果为金沙江干热河谷地带的碳汇供能评估提供了科学基础,为区域植被恢复和造林碳汇提供了理论基础和技术支持。展开更多
The Tibetan, Han and other ethnic people in Tibetan Autonomous Region labored hard to protect the forests and steppes and produce invisible ecological products. The forests and steppes in Qinghai -Tibet Plateau conser...The Tibetan, Han and other ethnic people in Tibetan Autonomous Region labored hard to protect the forests and steppes and produce invisible ecological products. The forests and steppes in Qinghai -Tibet Plateau conserved water and added the Jinsha River. In order to achieve sustainable development, it needs to construct compensating mechanism inter Provinces between the upper Yangtze River and the middle and lower Yangtze River, to implement carbon sink trading, and to assist farmers and herdsmen in the Tibet to get rich as soon as possible.展开更多
基金supported by the Special Fund for Public Benefit Scientific Research of Ministry of Land and Resources of China(No.201111022)IGCP/SIDA 598the China Geological Survey Projects (No.1212011087122,No.1212011220230)
文摘Using the Guancun River, an underground stream-fed river, in Rong＇an County of Guangxi, China as a case study, the daily biochemical cycle was examined in this paper based on the data collected a weeklong via high resolution data logger monitoring and high-frequency sampling. Furthermore, the loss of inorganic carbon along its flow path was estimated. Results show that chemical components of the groundwater input are quite stable, showing little change extent; while all of the chemical parameters from two downstream monitoring stations show diel variation over the monitoring period, suggesting that plant activity in the river has a strong influence on water chemistry of the river. The comparison of the input fluxes from the groundwater with the output fluxes of HCO~ estimated at the downstream monitoring station during the high-frequency sampling period shows a strong decrease of HCO~, indicating that the river is losing inorganic carbon along its flow path. The loss is estimated to be about 1,152 mmol/day/m of HCO~ which represent about 94.9 kg/day of inorganic carbon along the 1,350 m section of the Guancun River. It means that HCO~ entering the river from karst underground stream was either consumed by plants or trapped in the authigenic calcite and thus constitutes a natural sink of carbon for the Guancun karst system.
基金Supported by National Key Programme for Developing Basic Sciences G1998040900 Part 1 and IAPInnovation Foundation 8-1308.
文摘Using the summer (June to August) monthly mean data of the National Centers for Environmental Predictions (NCEP) - National Center for Atmospheric Research (NCAR) reanalysis from 1980 to 1997, atmospheric heat sources and moisture sinks are calculated. Anomalous circulation and the vertically integrated heat source with the vertical integrated moisture sink and outgoing longwave radiation (OLR) flux are examined based upon monthly composites for 16 great wet-spells and 8 great dry-spells over the middle-lower reaches of the Yangtze River. The wind anomaly exhibits prominent differences between the great wet-spell and the great dry-spell over the Yangtze River Valley. For the great wet-spell, the anomalous southerly from the Bay of Bengal and the South China Sea and the anomalous northerly over North China enhanced low-level convergence toward a narrow latitudinal belt area (the middle-lower reaches of the Yangtze River). The southerly anomaly is connected with an anticyclonic anomalous circulation system centered at 22 degreesN, 140 degreesE and the northerly anomaly is associated with a cyclonic anomalous circulation system centered at the Japan Sea. In the upper level, the anomalous northwesterly between an anticyclonic anomalous system with the center at 23 degreesN, 105 degreesE and a cyclonic anomalous system with the center at Korea diverged over the middle-lower reaches of the Yangtze River. On the contrary, for the great dry-spell, the anomalous northerly over South China and the anomalous southerly over North China diverged from the Yangtze River Valley in the low level. The former formed in the western part of a cyclonic anomalous system centered at 23 degreesN, 135 degreesE. The latter was located in the western ridge of an anticyclonic anomalous system in the northwestern Pacific. The upper troposphere showed easterly anomaly that converged over the middle-lower reaches of the Yangtze River. A cyclonic anomalous system in South China and an anticyclonic system centered in the Japan Sea enhanced the easterly. Large atmospheric heat source anomalies of opposite signs existed over the western Pacific - the South China Sea, with negative in the great wet-spell and positive in the great dry-spell. The analysis of heat source also revealed positive anomalous heat sources during the great wet-spell and negative anomalous heat sources during the great dry-spell over the Yangtze River valley. The changes of the moisture sink and OLR were correspondingly altered, implying the change of heat source anomaly is due to the latent heat releasing of convective activity. Over the southeastern Tibetan Plateau- the Bay of Bengal, the analysis of heat source shows positive anomalous heat sources during the great wet-spell and negative anomalous heat sources during the great dry-spell because of latent heating change. The change of divergent wind coexisted with the change of heat source. In the great wet-spell, southerly divergent wind anomaly in the low level and northerly divergent wind anomaly in high-level are seen over South China. These divergent wind anomalies are helpful to the low-level convergence anomaly and high-level divergence anomaly over the Yangtze River valley. The low-level northerly divergent wind anomaly and high-level southerly divergent wind anomaly over South China reduced the low-level convergence and high-level divergence over the Yangtze River valley during the great dry-spell.
文摘中国西南部的金沙江干热河谷地带是生态脆弱区,其新造林碳汇是林业碳汇的重要组成部分。但目前对干热河谷地区森林碳汇能力的研究尚不充分,新造林的碳汇能力尚不明确。以2014-2021年宾川县新造人工林为典型研究对象,通过陆地生态系统生产力模拟(BEPS)模型,研究金沙江干热河谷地带的碳汇能力特征。结果表明:(1)宾川新造人工林碳汇能力在2014-2016年逐渐升高,随后稳定,年均净生态系统生产力(net ecosystem productivity,NEP)为247.82±140.59 g C/(m^(2)/a);(2)宾川县人工林每年碳汇量自2014年起逐年增加,从2014年的2398.2 t C/a提升到2021年24028.1 t C/a;(3)宾川县人新造工林生态系统整体碳汇能力呈现东部和北部高,西南部低的分布趋势,各乡镇年均NEP在167.44~349.85 g C/(m^(2)/a),碳汇量在468.42~3832.72 t C/a;(4)不同造林类型的碳汇能力存在显著差异,阔叶灌木混合林的NEP显著高于其他类型林地。探究了宾川县新造工林的碳汇能力特征,研究结果为金沙江干热河谷地带的碳汇供能评估提供了科学基础,为区域植被恢复和造林碳汇提供了理论基础和技术支持。
基金Supported by the Major and Special Entrust Project of National Social Science Fund(XZ1111)the Planning Fund Project of Ministry of Education(10YJAZH08)
文摘The Tibetan, Han and other ethnic people in Tibetan Autonomous Region labored hard to protect the forests and steppes and produce invisible ecological products. The forests and steppes in Qinghai -Tibet Plateau conserved water and added the Jinsha River. In order to achieve sustainable development, it needs to construct compensating mechanism inter Provinces between the upper Yangtze River and the middle and lower Yangtze River, to implement carbon sink trading, and to assist farmers and herdsmen in the Tibet to get rich as soon as possible.
