A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;how...A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;however,knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking.Here,we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station.Using seasonal differences and statistical methods,we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration.Our results indicate that solar radiation,atmospheric humidity,and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration,and the impact shows temporal and spatial differences.Vegetation significantly impacts the oxygen concentration,with a contribution rate of 16.7%–24.5%,which is underestimated in existing research.Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation.To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau,we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage,carbon sinks and other factors to the near-surface atmospheric oxygen concentration.展开更多
Every year,millions of people travel to high-elevation regions(≥2500 m above sea level)for sightseeing,mountaineering,trekking,skiing or commercial and scientific research activities.As the largest and highest platea...Every year,millions of people travel to high-elevation regions(≥2500 m above sea level)for sightseeing,mountaineering,trekking,skiing or commercial and scientific research activities.As the largest and highest plateau of the world,the Qinghai-Tibet Plateau(QTP)is one of the most attractive tourist destinations because of its multiple splendid sceneries.High-altitude illnesses occur when the rate of ascent to a high altitude overcomes the ability of the individual to acclimatize.Chronic mountain sickness(CMS)is one of the most important high-altitude pathologies in most high-altitude regions over the world.展开更多
Both natural and human factors contributing to desertification were examined to understand the driving mechanisms of the desertification process in Zhalute Banner,Inner Mongolia of China.The coefficient of variation(C...Both natural and human factors contributing to desertification were examined to understand the driving mechanisms of the desertification process in Zhalute Banner,Inner Mongolia of China.The coefficient of variation(CV)and climate departure index(Z)were calculated to examine the fluctuations and trends of interannual variations of temperature and precipitation;TM remote sensing data was extracted to obtain the sandy land area;linear regression analysis was used to analyze climate changes and the socio-economic evolution over the years,and it was also used to standardize the variables,which included annual temperature,annual precipitation,human population,and livestock number,in order to measure the difference in the rate of change between climate and anthropogenic factors.The results showed that there was a rise of about 1.6uC in temperature but no significant change in precipitation from 1961 to 2000,which indicated a short-term climatic trend toward aridity in this area,a condition necessary for desertification.The fraction of precipitation in spring tended to increase whilst the fraction in autumn and winter decreased.Both the human population and livestock population had tripled and the cultivated area had doubled from 1961 to 2000,suggesting that socio-economic factors might have contributed more significantly to the desertification.Between 1988 and 1997,the sandy land area increased by 12.5%,nearly 2.4 times in the farming section.It could be concluded that the driving mechanisms of the desertification processes in Zhalute banner are mainly the policy of cropland expansion and the rising populations of humans and their livestock,which has affected the land use pattern in the past decades.展开更多
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0606&2019QZKK0906)。
文摘A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming.The Qinghai-Tibetan Plateau is located at a high altitude,and thus,it faces a hypoxia challenge;however,knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking.Here,we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station.Using seasonal differences and statistical methods,we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration.Our results indicate that solar radiation,atmospheric humidity,and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration,and the impact shows temporal and spatial differences.Vegetation significantly impacts the oxygen concentration,with a contribution rate of 16.7%–24.5%,which is underestimated in existing research.Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation.To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau,we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage,carbon sinks and other factors to the near-surface atmospheric oxygen concentration.
基金financially supported by the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0606 and 2019QZKK0906)the National Key Research&Development Program of China(2016YFA0602400)。
文摘Every year,millions of people travel to high-elevation regions(≥2500 m above sea level)for sightseeing,mountaineering,trekking,skiing or commercial and scientific research activities.As the largest and highest plateau of the world,the Qinghai-Tibet Plateau(QTP)is one of the most attractive tourist destinations because of its multiple splendid sceneries.High-altitude illnesses occur when the rate of ascent to a high altitude overcomes the ability of the individual to acclimatize.Chronic mountain sickness(CMS)is one of the most important high-altitude pathologies in most high-altitude regions over the world.
基金This research was supported by the National Natural Science Foundation of China(Grant No.40571057)the National Basic Research Program of China(973 Program)(Grant No.2007CB106807)。
文摘Both natural and human factors contributing to desertification were examined to understand the driving mechanisms of the desertification process in Zhalute Banner,Inner Mongolia of China.The coefficient of variation(CV)and climate departure index(Z)were calculated to examine the fluctuations and trends of interannual variations of temperature and precipitation;TM remote sensing data was extracted to obtain the sandy land area;linear regression analysis was used to analyze climate changes and the socio-economic evolution over the years,and it was also used to standardize the variables,which included annual temperature,annual precipitation,human population,and livestock number,in order to measure the difference in the rate of change between climate and anthropogenic factors.The results showed that there was a rise of about 1.6uC in temperature but no significant change in precipitation from 1961 to 2000,which indicated a short-term climatic trend toward aridity in this area,a condition necessary for desertification.The fraction of precipitation in spring tended to increase whilst the fraction in autumn and winter decreased.Both the human population and livestock population had tripled and the cultivated area had doubled from 1961 to 2000,suggesting that socio-economic factors might have contributed more significantly to the desertification.Between 1988 and 1997,the sandy land area increased by 12.5%,nearly 2.4 times in the farming section.It could be concluded that the driving mechanisms of the desertification processes in Zhalute banner are mainly the policy of cropland expansion and the rising populations of humans and their livestock,which has affected the land use pattern in the past decades.
