检索结果-南通市图书馆

青藏高原冻土区高寒草甸能量分配及蒸散发影响因子

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2024年第1期17卷 121-134页

作者： Zhaoyong Hu genxu wang Xiangyang Sun Kewei Huang Chunlin Song Yang Li Shouqin Sun Juying Sun Shan Lin State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China Hubei Key Laboratory of Basin Water Security Changjiang SurveyPlanningDesign and Research Co.Ltd.Wuhan 430010China

高寒草甸的能量分配和蒸散发对青藏高原多年冻土区水循环至关重要。然而,能量分配、蒸散发及其驱动因素的季节变化(冻融循环)仍需要明确。因此,本研究在位于青藏高原风火山流域的高寒草甸进行了为期4年的能量通量(包括潜热和感热)观测,... 详细信息

高寒草甸的能量分配和蒸散发对青藏高原多年冻土区水循环至关重要。然而,能量分配、蒸散发及其驱动因素的季节变化(冻融循环)仍需要明确。因此,本研究在位于青藏高原风火山流域的高寒草甸进行了为期4年的能量通量(包括潜热和感热)观测,并估算了大气边界参数(包括表面导度,解耦系数和Priestley-Taylor系数)。研究结果表明,研究区日均潜热(27.45±23.89 W/m^(2))和显热(32.51±16.72W/m^(2))分别占可利用能量的31.71%和50.14%。在降雨期,更多可利用能量被分配到潜热;而在冻结期,67.54±28.44%的可利用能量分配给显热。显热在降雨期间是潜热的一半,而由于冻结期较低的土壤水分含量及植被盖度,显热在冻结期间是潜热的7倍。研究区年均蒸散发为347.34±8.39 mm/year,接近年均降水量。较低的日均解耦系数(0.45±0.23)和Priestley-Taylor系数(0.60±0.29)表明高寒草甸的蒸散发受水分供应限制。然而,在降雨期由于降水充足,蒸散发受到可利用能量的限制。在过渡期,蒸散发和降水之间存在较大差异,表明在该季节上游冰川和雪的融水通过侧向流动补给到土壤中。本研究的结果表明,在未来模拟多年冻土区水和能量通量时应考虑大气边界参数的季节变化。

关键词：潜热通量显热通量冻融循环大气边界参数高寒草甸

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

川西亚高山森林苔藓与枯落物持水特征

山地学报 2024年第1期042卷 1-13页

作者：范金花谢汶天曹球铫王根绪孙守琴四川大学水力学与山区河流开发保护国家重点实验室四川大学水利水电学院

森林苔藓和枯落物在水土保持、水分涵养方面具备重要作用，但现有研究多单一关注苔藓或枯落物，对苔藓-枯落物层的整体效应的认识较少，尤其针对高海拔西南森林林下的苔藓-枯落物层，更为鲜见。本文以川西贡嘎山针叶林和阔叶林地被层（... 详细信息

森林苔藓和枯落物在水土保持、水分涵养方面具备重要作用，但现有研究多单一关注苔藓或枯落物，对苔藓-枯落物层的整体效应的认识较少，尤其针对高海拔西南森林林下的苔藓-枯落物层，更为鲜见。本文以川西贡嘎山针叶林和阔叶林地被层（苔藓、枯落物）为研究对象，通过野外调查、采样瓶取样浸水试验，分析了单一苔藓、单一枯落物及苔藓-枯落物整体的持水特征。结果表明：（1）贡嘎山苔藓和枯落物最大持水率为327.9%～432.6%,最大持水量为16.6～79.4 t/hm2,有效拦蓄量为7.1～34.2 t/hm2。针叶林比阔叶林具有更大的持水能力和水分拦蓄能力。（2）不同地被组分中，苔藓-枯落物层持水率、有效拦蓄率、持水量和拦蓄量最大，苔藓显著提高了针叶林地被层的水源涵养能力；（3）地被层持水量与时间呈对数关系，吸水速率与时间呈幂函数关系，不同组分持水量和持水率均在0～2 h内迅速增长，2～12 h内缓慢增长，12 h时几乎达到饱和状态。（4）与单一苔藓或枯落物层相比，苔藓-枯落物整体的吸水速率更快，具有更高效的短期降水拦蓄能力。本研究结果可为亚高山森林水源涵养和生态水文研究与保护提供参考和理论基础。

关键词：亚高山森林枯落物苔藓持水特征贡嘎山

Seasonal dynamics of suprapermafrost groundwater and its response to the freeing-thawing processes of soil in the permafrost region of Qinghai-Tibet Plateau

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2015年第4期58卷 727-738页

作者： CHANG Juan wang genxu LI ChunJie MAO TianXu College of Earth and Environment Science Lanzhou University Institute of Mountain Hazards and Environment Chinese Academy of Sciences

The suprapermafrost groundwater in permafrost region not only is an important component of the water cycle and land surface process, but also is closely associated with the charges of ecological environment in cold region. However, the seasonal dynamics, driving factors, and mechanism of suprapermafrost groundwater are not well understood. Based on observation at slope scale on suprapermafrost groundwater dynamics of typical alpine meadows in the Qinghai-Tibet Plateau, the seasonal dynamics, spatial distribution and driving factors of suprapermafrost groundwater were analyzed. The results showed that there were close relationships between the seasonal dynamics of suprapermafrost groundwater and the freezing-thawing processes of active soil in permafrost region. The seasonal dynamics of suprapermafrost groundwater and its slope distribution pattern were controlled by soil temperature of active layers. The phase and range of the suprapermafrost groundwater dynamics are determined by deep soil(below 60 cm depth) moisture and groundwater recharging sources. The relationship between active soil temperatures and dynamics of suprapermafrost groundwater levels was better described by Boltzmann functions. However, the influencing thresholds of soil temperature on groundwater dynamics varied at different depths of active layers and in different slope positions, which resulted in the significant spatial heterogeneity of suprapermafrost groundwater dynamics in slope scale. Land cover change and global warming certainly altered the dynamics of suprapermafrost groundwater and the hydraulic interaction between groundwater and rivers, and consequently altered the overall hydrologic cycle of watershed scale.

关键词：地下水动态多年冻土区土壤活性青藏高原季节变化解冻过程季节动态水位动态变化

Effects of Elevated Air Temperatures on Soil Thermal and Hydrologic Processes in the Active Layer in an Alpine Meadow Ecosystem of the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2012年第2期9卷 243-255页

作者： BAI Wei wang genxu LIU Guangsheng School of Environmental and Municipal Engineering Lanzhou Jiaotong UniversityLanzhou 730070China College of Resource and Environmental Science Lanzhou UniversityLanzhou 730000China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

In this study,effects of elevated air temperatures on thermal and hydrologic process of the shallow soil in the active layer were investigated. Open-top chambers(OTCs)were utilized to increase air temperatures 1-2℃ in OTC-1 and 3-5℃ in OTC-2 in the alpine meadow ecosystem on the Qinghai- Tibetan *** show that the annual air temperatures under OTC-1 and OTC-2 were 1.21℃ and 3.62℃ higher than the Control,*** entirely-frozen period of shallow soil in the active layer was shortened and the fully thawed period was prolonged with temperature *** maximum penetration depth and duration of the negative isotherm during the entirely-frozen period decreased, and soil freezing was retarded in the local scope of the soil profile when temperature ***, the positive isotherm during the fully-thawed period increased,and the soil thawing was *** moisture under different manipulations decreased with the temperature increase at the same depth. During the early freezing period and the early fully- thawed period,the maximum soil moisture under the Control manipulation was at 0.2 m deep,whereas under OTC-1 and OTC-2 manipulations,the maximum soil moisture were at 0.4-0.5 m deep. These results indicate that elevated temperatures led to a decrease of the moisture in the surface *** coupled relationship between soil temperature and moisture was significantly affected by the temperature *** the freezing and thawing processes, the soil temperature and moisture under different manipulations fit the regression model given by the equationθV=a/{1+exp[b(TS+c)]}+d.

关键词：高寒草甸生态系统温度升高水文过程青藏高原空气温度土壤热有源层土壤水分

Linkage between permafrost distribution and river runoff changes across the Arctic and the Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2020年第2期63卷 292-302页

作者： Chunlin SONG genxu wang Tianxu MAO Junchen DAI Daqing YANG Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China University of Chinese Academy of Sciences Beijing 100049China College of Forestry Guizhou UniversityGuiyang 550025China National Hydrology Research Centre Environment CanadaSaskatoon SK S7N 3H5Canada

River runoff in the Arctic and the Tibetan Plateau(TP) change significantly in recent decades. However, the mechanisms of the physical processes of permafrost river runoff change remain uncertain across large scale. This study investigated the mainstreams and tributaries of main Arctic and TP rivers dominated by permafrost and assessed the linkage between hydrological regime change and permafrost. The results show that the effects of permafrost on river runoff are highly dependent on the permafrost coverage of a watershed. For the past decades, the majority of the Arctic and TP basins showed increased discharge, while all of the studied basins showed increased baseflow, with faster increasing speed than total *** total discharge and baseflow annual change rate(ΔQ and ΔBF) increased with permafrost coverage, indicating the increments of streamflow are enhanced with high permafrost coverage. Meanwhile, the annual change of precipitation showed weak connection with total discharge and baseflow change. The high permafrost coverage basins showed high annual maximum/minimum discharge ratio(Qmax/Qmin), while the Qmax/Qminchanged slightly in low permafrost cover basins. Our results highlight the importance of permafrost coverage on streamflow regime change for permafrost basins across the northern hemisphere. Due to these linkage between permafrost extent and runoff regime change and the increasing changes of permafrost, more attention should be paid to the change of hydrological processes in permafrost-underlain basins.

关键词： Permafrost hydrology Arctic rivers Tibetan Plateau rivers Permafrost degradation Runoff change

Short-term effects of nitrogen deposition on soil respiration components in two alpine coniferous forests, southeastern Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2019年第3期30卷 1029-1041页

作者： Jian wang genxu wang Yu Fu Xiaopeng Chen Xiaoyan Song Land and Resource College China West Normal University Nanchong 637002SichuanPeople’s Republic of China Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences#9Block 4 Renminnanlu RoadWuhou DistrictChengdu 610041 People’s Republic of China Department of Politics and Administration China West Normal UniversityNanchong 637002SichuanPeople’s Republic of China Graduate University of Chinese Academy of Sciences Beijing 100049People’s Republic of China

Nitrogen (N) deposition to alpine forest ecosystems is increasing gradually, yet previous studies have seldom reported the effects of N inputs on soil CO2 flux in these ecosystems. Evaluating the effects of soil respiration on N addition is of great significance for understanding soil carbon (C) budgets along N gradients in forest ecosystems. In this study, four levels of N (0, 50, 100, 150 kg N ha^-1 a^-1) were added to soil in a Picea baifouriana and an Abies georgei natural forest on the Tibetan Plateau to investigate the effect of the N inputs on soil respiration. N addition stimulated total soil respiration (Rt) and its components including heterotrophic respiration (Rh) and autotrophic respiration (Ra);however, the promoted effects declined with an increase in N application in two coniferous forests. Soil respiration rate was a little greater in the spruce forest (1.05 μmol CO2 m^-2 s^-1) than that in the fir forest (0.97 μmol CO2 m^-2 s^-1). A repeated measures ANOVA indicated that N fertilization had significant effects on Rt and its components in the spruce forest and Rt in the fir forest, but had no obvious effect on Rh or Ra in the fir forest. Rt and its components had significant exponential relationships with soil temperature in both forests. N addition also increased temperature sensitivity (Q10) of Rt and its components in the two coniferous forests, but the promotion declined as N in put increased. Important, soil moisture had great effects on Rt and its components in the spruce forest (P0.05). Following N fertilization, Ra was significantly and positively related to fine root biomass, while Rh was related to soil enzymatic activities in both forests. The mechanisms underlying the effect of simulated N deposition on soil respiration and its components in this study may help in forecasting C cycling in alpine forests under future levels of reactive N deposition.

关键词： N addition Heterotrophic soil respiration Autotrophic soil respiration Q10 Alpine forest ecosystem

Influences of the degradation of swamp and alpine meadows on CO_2 emission during growing season on the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2007年第18期52卷 2565-2574页

作者： wang JunFeng wang genxu wang YiBo LI YuanShou College of Earth and Environment Sciences Lanzhou University Lanzhou 730000 China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 China Cold and Arid Regions Environment and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

CO2 emission fluxes of two types of ecosystem, swamp meadow and alpine meadow, in the Fenghuo- shan region of the Qinghai-Tibet Plateau were studied by the static chamber-portable infrared chro- matographic method. The results showed that there was large difference in the CO2 emission fluxes between the two ecosystems and in the same ecosystem of different degradation degrees. CO2 emis- sion flux of the swamp meadow gradually decreased with increasing degradation degree, while that of the alpine meadow gradually increased with increasing degradation degree except in May. The CO2 emission flux of undegraded swamp meadow was 65.1%―80.3% higher than that of undegraded alpine meadow; and the CO2 emission flux of moderately degraded swamp meadow was 22.1%―67.5% higher than that of alpine meadow; but the CO2 emission flux of severely degraded alpine meadow was 14.3%―29.5% higher than that of swamp meadow. The soil moisture content and temperature in the upper 5 cm soil layer and above-ground biomass were significantly correlated with the CO2 emission fluxes and regarded as the main environment factors to control the CO2 emission.

关键词：青藏高原沼泽草甸高山草甸生长季节二氧化碳释放量降解

Influence of short-term experimental warming on heat-waterprocesses of the active layer in a swamp meadow ecosystemof the Qinghai-Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Research in Cold and Arid Regions 2016年第2期8卷 125-134页

作者： GuangSheng Liu genxu wang College of Environmental Science and Engineering Xiamen University of TechnologyXiamenFujian 361024China Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengduSichuan 610041China

Climate change is now evident in the Qinghai-Tibet Plateau(QTP), with impacts on the alpine ecosystem, particularly on water and heat balance between the active layer and the atmosphere. Thus, we document the basic characteristics of changes in the water and heat dynamics in response to experimental warming in a typical alpine swamp meadow ecosystem. Data sets under open top chambers(OTC) and the control manipulations were collected over a complete year. The results show that annual(2008) air temperatures of OTC-1 and OTC-2 were 6.7 °C and 3.5 °C warmer than the control. Rising temperature promotes plant growth and development. The freeze-thaw and isothermal days of OTCs appeared more frequently than the control, owing to comparably higher water and better vegetation conditions. OTCs soil moisture decreased with the decrease of soil depth; however, there was an obviously middle dry aquifer of the control, which is familiar in QTP. Moreover, experimental warming led to an increase in topsoil water content due to poorly drained swamp meadow ecosystem with higher organic matter content and thicker root horizons. The results of this study will have some contributions to alpine cold ecosystem water-heat process and water cycle under climate change.

关键词： experimental warming open top chamber Qinghai-Tibet Plateau soil moisture soil temperature alpine swamp meadow ecosystem

Response of Biomass Spatial Pattern of Alpine Vegetation to Climate Change in Permafrost Region of the Qinghai-Tibet Plateau,China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2010年第4期7卷 301-314页

作者： ZHANG Yu wang genxu wang Yibo College of Resources & Environment Lanzhou UniversityLanzhou 730000China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China

Alpine ecosystems in permafrost region are extremely sensitive to climate *** determine spatial pattern variations in alpine meadow and alpine steppe biomass dynamics in the permafrost region of the Qinghai-Tibet Plateau,China,calibrated with historical datasets of above-ground biomass production within the permafrost region's two main ecosystems,an ecosystem-biomass model was developed by employing empirical spatialdistribution models of the study region's precipitation,air temperature and soil *** model was then successfully used to simulate the spatio-temporal variations in annual alpine ecosystem biomass production under climate *** a 0.44°C decade-1 rise in air temperature,the model predicted that the biomasses of alpine meadow and alpine steppe remained roughly the same if annual precipitation increased by 8 mm per decade-1,but the biomasses were decreased by 2.7% and 2.4%,respectively if precipitation was *** a 2.2°C decade-1 rise in air temperature coupled with a 12 mm decade-1 rise in precipitation,the model predicted that the biomass of alpine meadow was unchanged or slightly increased,while that of alpine steppe was increased by 5.2%.However,in the absence of any rise in precipitation,the model predicted 6.8% and 4.6% declines in alpine meadow and alpine steppe biomasses,*** response of alpine steppe biomass to the rising air temperatures and precipitation was significantly lesser and greater,respectively than that of alpine meadow biomass.A better understanding of the difference in alpine ecosystem biomass production under climate change is greatly significant with respect to the influence of climate change on the carbon and water cycles in the permafrost regions of the Qinghai-Tibet Plateau.

关键词：多年冻土地区植被生物量高寒草甸气候变化青藏高原空间格局中国高山生态系统