Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management a...Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantifed with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area （about 50.81%） was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.展开更多
Soil degradation, including rocky desertification,of the karst regions in China is severe. Karst landscapes are especially sensitive to soil degradation as carbonate rocks are nutrient-poor and easily eroded. Understa...Soil degradation, including rocky desertification,of the karst regions in China is severe. Karst landscapes are especially sensitive to soil degradation as carbonate rocks are nutrient-poor and easily eroded. Understanding the balance between soil formation and soil erosion is critical for long-term soil sustainability, yet little is known about the initial soil forming processes on karst terrain. Herein we examine the initial weathering processes of several types of carbonate bedrock containing varying amounts of non-carbonate minerals in the SPECTRA Critical Zone Observatory, Guizhou Province, Southwest China. We compared the weathering mechanisms of the bedrock to the mass transfer of mineral nutrients in a soil profile developed on these rocks and found that soil formation and nutrient contents are strongly dependent upon the weathering of interbedded layers of more silicate-rich bedrock(marls). Atmospheric inputs from dust were also detected.展开更多
Guizhou Province, located in the southwestern China, is an important mercury (Hg) production center. High levels of Hg were found in local environmental and biomass samples. The neurobiological disruptions induced in ...Guizhou Province, located in the southwestern China, is an important mercury (Hg) production center. High levels of Hg were found in local environmental and biomass samples. The neurobiological disruptions induced in brains of rats fed with Hg polluted rice collected from two experimental plots in Guizhou Province were studied. The plots are close to the Hg mine of Wanshang area and a chemical plant (where Hg is used as a catalyst for the pro-duction of acetaldehyde) of Qingzhen area. Rats were fed for 30 d before toxicological end points were tested. The results showed that the accumulations of Hg in rat’s brain of Qingzhen chemical plant group and Wanshang mine group were significantly higher than those of Shanghai group (con-trol group) (P<0.01). The neural transmitters, including ace-tylcholine (Ach), acetylcholine enzyme (AchE), nitric oxide and nitricoxide synthase (NOS), in rat’s brain were signifi-cantly affected. Oxidative stress was observed in the expo-sure groups. The expression levels of the immediately early gene (IEG), c-fos and c-FOS proteins were induced by the Hg polluted rice. It was noted that the IEG (c-fos) participated in the neurotoxic process induced by the Hg polluted rice. IEG response to Hg might be dependent on interactions between neural transmitter and oxidative damage. c-fos could be used as an effective index of detecting and assessing the neurotox-icity of Hg. The results suggested that it should be alert to mental health problem in human beings eating Hg-polluted food. More efforts are necessary to protect the local ecosys-tem and human health in the Hg polluted areas such as Wangshan and Qingzhen in Guizhou Province of China.展开更多
对岩石风化强度反应敏感的化学风化指标是定量评价岩石风化程度的重要参数。评述了包括帕克风化指数(weathering index of Parker,WIP)、风化势能指数(weathering potential index,WPI)、化学蚀变指数(chemical index of alteration,CIA...对岩石风化强度反应敏感的化学风化指标是定量评价岩石风化程度的重要参数。评述了包括帕克风化指数(weathering index of Parker,WIP)、风化势能指数(weathering potential index,WPI)、化学蚀变指数(chemical index of alteration,CIA)等12种在以往研究中被认为适合用于岩浆岩风化程度判定的化学风化指标的优点及其局限性。引入了岩石氧化因数X_(o)(X_(o)=Fe_(2)O_(3)/(FeO+Fe_(2)O_(3)))评价火山岩的风化程度,并使用该指标评价了12种化学风化指标在评价超基性岩和基性岩风化中的适用性。在黔西晚二叠世超基性岩和基性玄武岩的实际应用中,将X_(o)≤0.44和X_(o)≤0.55作为超基性岩和基性玄武岩未遭受风化的下限,结合定性分析结果,按风化程度将两种岩石分为新鲜岩石、微风化岩石、中风化岩石、强风化岩石和全风化岩石。X_(o)与12种化学风化指标散点交会的结果显示:BWI、A-FM、LOI这3种指标既适合于风化初期超基性岩和基性玄武岩风化程度的评价,也适合风化中后期超基性岩和基性玄武岩风化程度的评价,其余9种指标仅对风化中后期超基性岩和基性玄武岩的风化程度反应敏感。研究可为超基性岩和基性玄武岩岩质区的工程地质调查与勘察、潜在地质灾害评价、地质灾害隐患防治等提供新思路、新方法,对相似岩质区的岩体风化程度评价研究提供参考。展开更多
基金Under the auspices of Major Basic Reseach Development Program of China (973 Program) (No. 2006CB403201)
文摘Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantifed with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area （about 50.81%） was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.
基金supported by the National Environmental Research Council of the UK(Grant Nos.NE/N007530/1 and NE/N007603/1)the National Science Foundation of China(Grant No.41571130042)
文摘Soil degradation, including rocky desertification,of the karst regions in China is severe. Karst landscapes are especially sensitive to soil degradation as carbonate rocks are nutrient-poor and easily eroded. Understanding the balance between soil formation and soil erosion is critical for long-term soil sustainability, yet little is known about the initial soil forming processes on karst terrain. Herein we examine the initial weathering processes of several types of carbonate bedrock containing varying amounts of non-carbonate minerals in the SPECTRA Critical Zone Observatory, Guizhou Province, Southwest China. We compared the weathering mechanisms of the bedrock to the mass transfer of mineral nutrients in a soil profile developed on these rocks and found that soil formation and nutrient contents are strongly dependent upon the weathering of interbedded layers of more silicate-rich bedrock(marls). Atmospheric inputs from dust were also detected.
基金supported by the Key and Innova tion Projects of the Chinese Academy of Sciences(Grant No.KZCX3-SW-437)the National Natural Science Foundation of China(Grant No.20177013).
文摘Guizhou Province, located in the southwestern China, is an important mercury (Hg) production center. High levels of Hg were found in local environmental and biomass samples. The neurobiological disruptions induced in brains of rats fed with Hg polluted rice collected from two experimental plots in Guizhou Province were studied. The plots are close to the Hg mine of Wanshang area and a chemical plant (where Hg is used as a catalyst for the pro-duction of acetaldehyde) of Qingzhen area. Rats were fed for 30 d before toxicological end points were tested. The results showed that the accumulations of Hg in rat’s brain of Qingzhen chemical plant group and Wanshang mine group were significantly higher than those of Shanghai group (con-trol group) (P<0.01). The neural transmitters, including ace-tylcholine (Ach), acetylcholine enzyme (AchE), nitric oxide and nitricoxide synthase (NOS), in rat’s brain were signifi-cantly affected. Oxidative stress was observed in the expo-sure groups. The expression levels of the immediately early gene (IEG), c-fos and c-FOS proteins were induced by the Hg polluted rice. It was noted that the IEG (c-fos) participated in the neurotoxic process induced by the Hg polluted rice. IEG response to Hg might be dependent on interactions between neural transmitter and oxidative damage. c-fos could be used as an effective index of detecting and assessing the neurotox-icity of Hg. The results suggested that it should be alert to mental health problem in human beings eating Hg-polluted food. More efforts are necessary to protect the local ecosys-tem and human health in the Hg polluted areas such as Wangshan and Qingzhen in Guizhou Province of China.
文摘对岩石风化强度反应敏感的化学风化指标是定量评价岩石风化程度的重要参数。评述了包括帕克风化指数(weathering index of Parker,WIP)、风化势能指数(weathering potential index,WPI)、化学蚀变指数(chemical index of alteration,CIA)等12种在以往研究中被认为适合用于岩浆岩风化程度判定的化学风化指标的优点及其局限性。引入了岩石氧化因数X_(o)(X_(o)=Fe_(2)O_(3)/(FeO+Fe_(2)O_(3)))评价火山岩的风化程度,并使用该指标评价了12种化学风化指标在评价超基性岩和基性岩风化中的适用性。在黔西晚二叠世超基性岩和基性玄武岩的实际应用中,将X_(o)≤0.44和X_(o)≤0.55作为超基性岩和基性玄武岩未遭受风化的下限,结合定性分析结果,按风化程度将两种岩石分为新鲜岩石、微风化岩石、中风化岩石、强风化岩石和全风化岩石。X_(o)与12种化学风化指标散点交会的结果显示:BWI、A-FM、LOI这3种指标既适合于风化初期超基性岩和基性玄武岩风化程度的评价,也适合风化中后期超基性岩和基性玄武岩风化程度的评价,其余9种指标仅对风化中后期超基性岩和基性玄武岩的风化程度反应敏感。研究可为超基性岩和基性玄武岩岩质区的工程地质调查与勘察、潜在地质灾害评价、地质灾害隐患防治等提供新思路、新方法,对相似岩质区的岩体风化程度评价研究提供参考。
