检索结果-内蒙古大学图书馆

Characteristics of Rare Earth Elements in Sediments for Indicating Anthropogenic Impacts on Plateau lakes: An Example from Qinghai lake, Ne Tibetan Plateau

SSRN

引用

SSRN 2023年

作者： Tian, Shuhan Meng, Yingyi Wan, Xiaoming Yang, Xiao Wang, lingqing Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Department of Occupational and Environmental Health School of Public Health Qingdao University Qingdao266021 China

Qinghai lake, the largest saline lake in China, plays a crucial role in maintaining ecological security and water circulations in the Tibetan Plateau. At the same time, the plateau lake might be sensitive and vulnerable to emerging pollutants, which makes it important to identify the pollution degree and sources and subsequently take protective measures. In this study, rare earth element (REE) characteristics combined with a receptor model (Positive Matrix Factorization) were used to analyze the source contributions. The concentrations of tested REEs in Qinghai lake sediments (6.17 ± 0.70 mg/kg for Sc, 7.79 ± 1.60 mg/kg for Y, 10.16 ± 4.57 mg/kg for la, 20.06 ± 6.43 mg/kg for Ce, and 1.08 ± 0.17 mg/kg for Yb) were much lower than reported values for other lakes in China, and the geo-accumulation index results indicated unpolluted levels for REEs. lanthanum and Ce had higher coefficients of variation than other rare earth elements and had abnormally high values around the entrances of rivers, indicating possible disturbances from exogenous sources. The receptor model recognized that 25% of the 18 tested elements and 50% of REEs in the sediment may be carried by river inputs. REE characteristics further suggested that the exogenous source might contain traffic and/or fossil fuel combustion components. It is suggested that relevant measures should be taken to prevent further contamination in Qinghai lake. © 2023, The Authors. All rights reserved.

关键词： lakes

来源：评论

学校读者我要写书评

暂无评论

The Biophysical and Crop Yield Effects of Irrigation and Their Changes in China's Drylands

SSRN

引用

SSRN 2024年

作者： Zi, Shuangshuang li, Yan Zhang, Jingwen Hou, Chengcheng lin, Huiqing Xu, Zhengjie Dong, Jinwei Fu, Bojie State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical Science Beijing Normal University Beijing China Institute of Land Surface System and Sustainable Development Faculty of Geographical Science Beijing Normal University Beijing China School of Civil Engineering Center of Water Resources and Environment Sun Yat-sen University Zhuhai China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China

Irrigation is critical for food production, especially in arid and semi-arid regions. Irrigation has complex and interactive effects on local climate, evapotranspiration, and crop growth. Here we use satellite remote sensing data and statistical models to quantify the biophysical irrigation effects on land surface temperature (lST), evapotranspiration (ET), crop greenness and crop yield effects in China’s drylands. Results show that during 2001-2012, irrigation in China's drylands leads to a significant cooling effect on daytime lST (-0.52 °C), a weak cooling effect on nighttime lST (-0.14 °C), an increase in ET (+0.16 mm/d), and enhanced crop greenness (+0.02) and maize yields (+3.4 ton/ha;55%) compared with rainfed croplands. The irrigation effects have strong spatiotemporal variations, with greater effects in the dry regions/periods with higher irrigation intensity. It needs to be noted that the irrigation cooling effects have gradually weakened since 2001, while the enhanced effects on ET, greenness and maize yields are still increasing. This is mainly driven by the decline in irrigation water use but the increase in irrigation water productivity due to the adoption of water-saving irrigation technologies. This study improves our understanding on the irrigation effects and their responses to changing irrigation practices and climate in water-limited regions. © 2024, The Authors. All rights reserved.

关键词： Evapotranspiration

来源：评论

学校读者我要写书评

暂无评论

Hazards of extreme events in China under different global warming targets

引用

Big Earth Data 2020年第2期4卷 153-174页

作者： Jiangbo Gao lulu liu Shaohong Wu Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijingChina College of Resources and Environment University of Chinese Academy of SciencesBeijingChina

Changes in the frequency and intensity of extreme events affect the risk pattern of risk-bearing bodies and the effectiveness of response *** on future climate scenario data,in this study,we identify global warming periods of 1.5℃ and 2℃ above pre-industrial levels,and the temporal and spatial patterns of temperature and precipitation in China during the same period,propose a methodology for risk assessment and integrated analysis of extreme events,build a database of extreme events and their hazards in China in the context of climate change,and assess the hazards caused by extreme events(i.e.,heatwaves,floods,and droughts)in China under different warming *** the RCP4.5 and RCP8.5 scenarios,global temperatures increase by 1.5℃ and 2℃ above preindustrial levels by 2029 and 2026 and by 2050 and 2040,*** warming would be fast in the north and slow in the south,the warming of the Qinghai-Tibet Plateau would accelerate,and the precipitation would increase in the north and decrease in the south,but the trend of the precipitation reduction in the south would be more significant under the RCP8.5 *** 2℃ of warming,the hazard index of severe heatwaves in the North China Plain,parts of South China,and the western part of Inner Mongolia would double that of 1.5℃ *** differences in extreme precipitation would increase,especially under the RCP8.5 scenario,the hazard index of severe floods in parts of East China would be about twice that of 1.5℃ *** the joint influence of rising temperature and changing precipitation,the drought situation would be alleviated under the RCP4.5 scenario,but it is intensified under the RCP8.5 *** 2℃ of warming,the hazard index of severe droughts in some areas would reach three times that of 1.5℃ *** the integrated hazard of the three types of extreme events,the areas of high and medium hazards would expand,while the areas of low hazard would *** 2℃ of warming,t

关键词： Climate change warming target extreme events integrated hazard spatialtemporal pattern

来源：评论

学校读者我要写书评

暂无评论

Heterogeneity of water-retention capacity of forest and its influencing factors based on meta-analysis in the Beijing-Tianjin-Hebei region

引用

Journal of Geographical Sciences 2021年第1期31卷 69-90页

作者： SHI Xiaoli DU Chenliang GUO Xudong SHI Wenjiao Hebei Key Laboratory of Environmental Change and Ecological Construction College of Resources and Environmental SciencesHebei Normal UniversityShijiazhuang 050024China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Hebei Technology Innovation Center for Remote Sensing Identification of Environmental Change Shijiazhuang 050024China Land Surveying and Planning Institute Key Laboratory of Land UseMinistry of Natural ResourcesBeijing 100035China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Water retention is important in forest ecosystem services. The heterogeneity analysis of water-retention capacity and its influencing factors is of great significance for the construction of water-retention functional areas, restoration of vegetation, and the protection of forest ecosystems in the Beijing-Tianjin-Hebei region. A total of 1366 records concerning water-retention capacity in the canopy layer, litter layer, and soil layer of forest ecosystem in this region were obtained from 193 literature published from 1980 to 2017. The influencing factors of water-retention capacity in each layer were analyzed, and path analysis was used to investigate the contribution of the factors to the water-retention capacity of the three layers. The results showed that mixed forests had the highest water-retention capacity, followed by broad-leaved forests, coniferous forests, and shrub forests. In addition, no matter the forest type, the ranking of the water-retention capacity was soil layer, canopy layer, and litter layer from high to low. The main influencing factors of water-retention capacity in forest canopy were leaf area index and maximum daily precipitation(R2=0.49), and the influencing coefficients were 0.34 and 0.30, respectively. The main influencing factors of water-retention capacity in the litter layer were semi-decomposed litter(R2=0.51), and the influencing coefficient was 0.51. The main influencing factors of water-retention capacity in the soil layer were non-capillary porosity and soil depth(R2=0.61), the influencing coefficients were 0.60 and 0.38, respectively. This study verifies the simulation of the water balance model or inversion of remote sensing of the water-retention capacity at the site scale, and provides scientific basis for further study of the impact of global change on water retention.

关键词： meta-analysis path analysis water retention Beijing-Tianjin-Hebei region

来源：评论

学校读者我要写书评

暂无评论

Effect of 9-year water and nitrogen additions on microbial necromass carbon content at different soil depths and its main influencing factors

引用

Science of the Total Environment 2024年 954卷 176825页

作者： Yuan, Xiujin Qi, Yuchun Guo, Yu Dong, Yunshe Peng, Qin Yan, Zhongqing li, Zhaolin Dong, Ruyue Zheng, Yilian Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China Wetland Research Center Institute of Ecological Conservation and Restoration Chinese Academy of Forestry Beijing100091 China State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing10085 China

Microbial necromass carbon (MNC) is a major source of soil organic carbon (SOC) pool, significantly influencing soil carbon sequestration. The effects of long-term water and nitrogen addition on MNC in soils at different depths, as well as their interactions, remain poorly understood. In this study, we examined the influence of water addition (+51.67 mm), nitrogen addition (25, 50, 100 kg N ha−1 yr−1), and their interactions on MNC accumulation at different soil depths in temperate grasslands. The addition of water and nitrogen over nine years has been observed to exhibit a decreasing trend in the MNC at different soil depths. Notably, MNC in the topsoil layer (0–10 cm) decreased significantly by 18.56 % under low nitrogen addition treatment, while MNC in the subsoil layer (40–60 cm) declined significantly by 27.19 % under high nitrogen addition treatment. Fungal microbial necromass carbon (FNC) contributed 3.25 times more to SOC than bacterial microbial necromass carbon (BNC). In the 0–10 cm soil layer, MNC is primarily governed by both microbial attributes and the physicochemical properties of the soil, in the 20–40 cm soil layer, the physicochemical properties of the soil predominantly control MNC, in the 40–60 cm layer, microbial characteristics exert a more significant influence on MNC. Collectively, our observations suggest that soil MNC decreased with the addition of water and nitrogen in the 0–60 cm soil slope, which could enable the accurate prediction of global change impacts on the accumulation of soil carbon, thus facilitating the implementation of strategies to augment soil carbon sequestration. © 2024

关键词： Microbial community characteristics Microbial enzyme activity Microbial necromass carbon Nitrogen addition Water addition

来源：评论

学校读者我要写书评

暂无评论

The Connectivity of Host Vegetation is Decisive for the Natural Spread of Pine Wilt Disease

SSRN

引用

SSRN 2023年

作者： Huang, Jixia Zhao, Xiaoting Mo, Xiumei Fang, Guofei Wu, Jin liu, Ronggao Precision Forestry Key Laboratory of Beijing Beijing Forestry University Beijing100083 China Key Laboratory of State Forestry Administration on Forest Pest Monitoring and Warning Shenyang110034 China Research Area of Ecology and Biodiversity School for Biological Sciences The University of Hong Kong Hong Kong Key Laboratory of Land Surface Pattern and Simulation Chinese Academy of Sciences Beijing100101 China

Pine wilt disease, a devastating disease in forest ecosystems worldwide, is known as the 'cancer' of pine trees and has caused substantial economic, ecological and social losses in China. Studies on the impact of pine wilt disease have mainly focused on static habitat factors;research on the dynamics of its spread over long time scales is lacking. This study aims to reveal the spatial and temporal spread of the natural invasion of pine wilt disease through an analysis of long time series at macroscopic scales. It analyses the driving mechanisms of host and wind fields in the natural spread of pine wilt disease and validates such mechanisms through simulations. The results show that the occurrence of pine wilt disease in the Yangtze River Delta region of China demonstrated a "steady rise - fluctuation - outbreak" from 1982 to 2019. The host forest played a decisive role in the natural spread of the disease, while the wind field played a supporting role, with the contribution of host forest landscape connectivity, host forest area share, mean wind speed and wind frequency at the junction being 31.8%, 28.7%, 22.6% and 8.8%, respectively. The interaction between host forest area share and mean wind speed greatly enhanced the risk of pine nematode transmission. Vectorial metacellular automata simulations of pine nematode transmission spread in the Yangtze River Delta yielded results with an accuracy of 0.803, verifying the reliability of the explanatory power. This study quantifies the contribution of host forest connectivity to the natural spread of pine wilt disease and provides a scientific basis and new ideas for preventing and controlling its spread, which is important for protecting forest resources, improving the ecological environment, and promoting sustainable economic and social development. © 2023, The Authors. All rights reserved.

关键词： Transmissions

来源：评论

学校读者我要写书评

暂无评论

Geographic conditions impact the relationship between plant phenology and phylogeny

引用

Science of the Total Environment 2024年 945卷 174083页

作者： Shahzad, Khurram Alatalo, Juha Mikael Zhu, Mengyao Cao, lijuan Hao, Yulong DAI, Junhu Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research CAS Beijing100101 China Nebraska Food for Health Center Department of Food Science and Technology University of Nebraska-Lincoln LincolnNE United States Environmental Science Center Qatar University Doha Qatar University of Chinese Academy of Sciences Beijing100049 China

Plant phenology is influenced by a combined effect of phylogeny and climate, although it is yet unclear how these two variables work together to change phenology. We synthesized 107 previously published studies to examine whether phenological changes were impacted by both phylogeny and climate changes in various geographical settings globally. Phenological observation data from 52,463 plant species at 71 sites worldwide revealed that 90 % of phenological records showed phylogenetic conservation. i.e., closely related species exhibited similar phenology. To explore the significant and non-significant phylogenetic conservation between plant phenophases, our dataset comprises 5,47,000 observation records from the four main phenophases (leaf bud, leaf, flower, and fruit). Three-dimensional geographical distribution (altitude, latitude, and longitude) data analysis revealed that plant phenology may exhibit phylogenetic signals at finer special scales (optimal environmental conditions) that vanish in high altitude and latitude regions. Additionally, climatic sensitivity analysis suggested that phylogenetic signals were associated with plant phenophases and were stronger in the regions of ideal temperature (7–18 °C) and photoperiod (10–14 h) and weaker in harsh climatic conditions. These results show that phylogenetic conservation in plant phenological traits is frequently influenced by the interaction of harsh climatic conditions and geographical ranges. This meta-analysis enhances our knowledge of predicting species responses over geographic gradients under varied climatic conditions. © 2024 Elsevier B.V.

关键词： Phylogenetic

来源：评论

学校读者我要写书评

暂无评论

Relationships between climate change, agricultural development and social stability in the Hexi Corridor over the last 2000 years

引用

Science China Earth Sciences 2019年第9期62卷 1453-1460页

作者： Yanpeng lI Quansheng GE Huanjiong WANG Haolong lIU Zexing TAO Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

This case study of the Hexi Corridor, Northwestern China, utilizes statistical methods to estimate quantitatively the interaction at a regional level between climate change, ancient social developments, and political coping strategies over the past 2000 years. The data is sourced from high-resolution reconstructions of climate series(temperature and precipitation), and historical records of cultivated land, war, population, and changes in regional administrative systems. The results show that moisture conditions played a more significant role than temperature in driving land reclamation in the Hexi Corridor. Analysis also showed a negative correlation between war frequency and the area of cultivated land in the Corridor over 20-year time intervals. Population growth was found to have a significant positive correlation with the cultivated land area during the study period. The results indicate that a climate-induced decline in agricultural production and the subsequent fluctuations in population could act as a trigger for social unrest, which is especially true at the mutual decadal time-scales. However, the interaction with administrative reform also suggests that, in the face of social and economic turmoil, a reasonable administrative hierarchy could strengthen the social governance of regional government, and promote social stability and economic development at a regional level. The study substantiates this notion with empirical quantitative evidence.

关键词： Climate change Agricultural development Social stability Regional administrative reform Hexi Corridor

来源：评论

学校读者我要写书评

暂无评论

Temporal and Spatial Changes of Hydrographic Connectivity with the Development of Agriculture, Industry and living: A Case Study at Yellow River Basin in Henan Section During the last Two Decades

SSRN

引用

SSRN 2023年

作者： li, Zhiying Yang, Fen Zhou, Jianli Wei, Chaoyang Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China University of Chinese Academy of Sciences Beijing100049 China College of Agriculture Yangtze University Jingzhou434025 China

The hydrographic connectivity has been intensively documented as a crucial indicator for analyzing the structural patterns of river and lake systems and water storage capacities as well. However, the impact of the temporal and spatial changes of the hydrographic connectivity in a large river basin on the development of agriculture, industry and living has rarely been studied. For this purpose, the area in Henan province, China, where the Yellow River flow through, was selected as a case study. Methods such as remote sensing-based feature interpretation, classification and modified normalized difference water index(MNDWI) extraction were employed to investigate the interannual variation of the structure and functional connectivity of the river system during the last two decades from 2000-2020. It comes out that the predominant land use type in the study area is agricultural, which has experienced a steady annual decline. In contrast, reservoir and lake areas initially increased before subsequently decreasing, displaying an opposite trend to rivers - the two smallest land use types in this region. Human activities have exerted a profound influence on these changes. Under anthropogenic influence, the structural form of the water system in the study area has gradually improved, exhibiting an increasing complexity of river networks and a stabilizing connectivity configuration. Within the functional connectivity of the study area, the natural function remains well-preserved, while the social function demonstrates a positive correlation with the expansion of industrial activities, eventually achieving an exceptional level. The study area's water use structure is predominantly agricultural, with water use for residential purposes continuing to grow, which has a more favorable impact on the hydrographic connectivity. This research illustrates that hydrographic connectivity alterations can reflect the regional economic and social development history and trend along a large ri

关键词： Rivers

来源：评论

学校读者我要写书评

暂无评论

land use and land cover change within the Koshi River Basin of the central Himalayas since 1990

引用

Journal of Mountain Science 2021年第1期18卷 159-177页

作者： XIE Fang-di WU Xue lIU lin-shan ZHANG Yi-li Basanta PAUDEl Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research(IGSNRR)Chinese Academy of Sciences(CAS)Beijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China University of Chinese Academy of Sciences Beijing 100049China Kathmandu Center for Research and Education Chinese Academy of Sciences/Tribhuvan UniversityKirtipurKathmanduNepal

land change is a cause and consequence of global environmental *** use and land cover have changed considerably due to increasing human activities and climate change,which has become the core issue of major international research *** study interprets land use and land cover status and the changes within the Koshi River Basin(KRB)using landsat remote sensing(RS)image data,and employs logistic regression model to analyze the influence of natural and socioeconomic driving forces on major land cover *** results showed that the areas of built-up land,bare land and forest in KRB increased from 1990 to 2015,including the largest increases in forest and the highest growth rate in construction *** of glacier,grassland,sparse vegetation,shrub land,cropland,and wetland all decreased over the study *** the perspective of driving analysis,the role of human activities in land use and land cover change is significant than climate *** expansion is the reclamation of cropland by farmers,mainly from early ***,labor force separation,geological disasters and drought are the main factors of cropland *** increase of forest area in India and Nepal was attributed to the government’s forest protection policies,such as Nepal’s community forestry has achieved remarkable *** expansion and contraction of grassland were both dominated by climatic *** probability of grassland expansion increases with temperature and precipitation,while the probability of grassland contraction decreases with temperature and precipitation.

关键词： Koshi River Basin land use and land cover change logistic model Grassland expansion Grassland contraction Mt.Qomolangma

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：