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Floristic composition and edaphic relationships in ferruginous campo rupestre reference ecosystems
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作者 G.Wilson FERNANDES Letícia RAMOS +3 位作者 Dario C.PAIVA Jéssica CUNHA-BLUM Vanessa Matos GOMES Daniel NEGREIROS 《Journal of Mountain Science》 SCIE CSCD 2024年第3期719-733,共15页
Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferrugin... Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferruginous campo rupestre(rupestrian grassland known as Canga in Brazil),are even more susceptible to severe impacts due to their extreme habitat conditions and low resilience.The determination of reference ecosystems based on the intrinsic characteristics of the ecosystem is essential for conservation as well as to the implementation of ecological restoration.We proposed the reference ecosystem of the three main types of habitats of the ferruginous campo rupestre based on their floristic composition.We described the floristic composition of each habitat and evaluated the physicochemical properties of the soils and the relationship between plants and soils.All three habitats showed high diversity of plant species and many endemic species,such as Chamaecrista choriophylla,Cuphea pseudovaccinium,Lychnophora pinaster,and Vellozia subalata.The distribution of vegetation was strongly related with the edaphic characteristics,with a set of species more adapted to high concentration of base saturation,fine sand,organic carbon,and iron,while another set of species succeeded in more acidic soils with higher S and silt concentration.We provide support for the contention that the ferruginous campo rupestre is a mosaic of different habitats shaped by intrinsic local conditions.Failure to recognize the floristic composition of each particular habitat can lead to inappropriate restoration,increased habitat homogenization and increased loss of biodiversity and ecosystem services.This study also advances the knowledge base for building the reference ecosystem for the different types of ferruginous campo rupestre habitats,as well as a key database for highlighting those species contribute most to community assembly in this diverse and threatened tropical mountain ecosystem. 展开更多
关键词 Canga Ecological restoration Extreme ecosystem Non-forest ecosystems Rupestrian grassland Taxon environment relationships
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Enhancing Secure Development in Globally Distributed Software Product Lines: A Machine Learning-Powered Framework for Cyber-Resilient Ecosystems
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作者 Marya Iqbal Yaser Hafeez +5 位作者 Nabil Almashfi Amjad Alsirhani Faeiz Alserhani Sadia Ali Mamoona Humayun Muhammad Jamal 《Computers, Materials & Continua》 SCIE EI 2024年第6期5031-5049,共19页
Embracing software product lines(SPLs)is pivotal in the dynamic landscape of contemporary software devel-opment.However,the flexibility and global distribution inherent in modern systems pose significant challenges to... Embracing software product lines(SPLs)is pivotal in the dynamic landscape of contemporary software devel-opment.However,the flexibility and global distribution inherent in modern systems pose significant challenges to managing SPL variability,underscoring the critical importance of robust cybersecurity measures.This paper advocates for leveraging machine learning(ML)to address variability management issues and fortify the security of SPL.In the context of the broader special issue theme on innovative cybersecurity approaches,our proposed ML-based framework offers an interdisciplinary perspective,blending insights from computing,social sciences,and business.Specifically,it employs ML for demand analysis,dynamic feature extraction,and enhanced feature selection in distributed settings,contributing to cyber-resilient ecosystems.Our experiments demonstrate the framework’s superiority,emphasizing its potential to boost productivity and security in SPLs.As digital threats evolve,this research catalyzes interdisciplinary collaborations,aligning with the special issue’s goal of breaking down academic barriers to strengthen digital ecosystems against sophisticated attacks while upholding ethics,privacy,and human values. 展开更多
关键词 Machine Learning variability management CYBERSECURITY digital ecosystems cyber-resilience
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Assessment of Ecosystems Damages Caused by Russian War against Ukraine
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作者 Yevhen Bezsonov 《Open Journal of Ecology》 2024年第10期754-788,共35页
The question of the impact of war on ecosystems still remains secondary in the internal and external policy of states, society and the agenda of international organizations. From the point of view of losses in monetar... The question of the impact of war on ecosystems still remains secondary in the internal and external policy of states, society and the agenda of international organizations. From the point of view of losses in monetary terms, the values of ecosystem damages obtained in the work, which are a consequence of the impact of hostilities on the environment, correspond to the annual budgets of the largest countries in the world or exceed them. The presented calculations significantly exceed the known normative methods, the use of which in the conditions of war is limited in space and time. Objective difficulties associated with the uncertainty of many processes of the development of ecological systems and their reaction to the multifactorial impact of war are also significant limitations. Therefore, as part of the study, a method of assessing the impact of war on the environment is proposed, which is based on the patterns of energy flows in ecosystems from the moment it is binding by producers. This made it possible to take into account in the calculations the principle of functional integrity of the ecological system, according to which the destruction or damage of the components of a functionally whole environment will necessarily cause negative phenomena in the development of ecological systems. The results are presented in the form of real values of ecological losses in energy and monetary equivalents, as consequences of the loss of ecosystem services. As the results of the research show, the minimum amount of damage to ecosystems from Russian tanks is 43,500 USD per day. Environmental damage from Russian fighter jets has been estimated at $1.5 billion per week since the start of the war. Noise from military operations causes losses of at least 2.3 billion US dollars per year. The obtained results create prerequisites for improving the system of ensuring environmental safety at the local, state, and international levels and transferring the obtained solutions into safety-shaping practice. 展开更多
关键词 Ecosystem Services Damage Assessment Environmental Security Russia’s War against Ukraine
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Microclimate and Its Formation Mechanism in Cunninghamia lanceolata Hook. Plantation Ecosystems in the Subtropical Zone of China 被引量:2
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作者 张合平 田大伦 +1 位作者 康文星 艾顺儒 《Forestry Studies in China》 CAS 2001年第2期26-31,共6页
Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in... Microclimate characteristics and related environmental energy mechanisms were examined based on the long term located observations in the mature, thinned and young Cunninghamia lanceolata plantation ecosystems in western Hunan Province, China. The results show that the mature plantation ecosystem can improve the microclimate significantly by regulating the amount and spatial distribution of environmental energy, which delineates the pattern of the microclimate in forest ecosystems in the process of ecological restoration. Compared with the young plantation, the mature plantation ecosystem decreased annual mean air temperature by 0 4℃. The maximum decrease in monthly mean air temperature was 2 3℃. The mature plantation ecosystem decreased annual mean ground temperature by 1 2℃ with a maximum decrease in monthly mean ground temperature of 2 3℃. Mainly due to the dense canopy, the mature forest ecosystem regulates the distribution of radiation energy, and expenditure ratios of heat budget and principal energy components to decrease temperature or make it even. 展开更多
关键词 Cunninghamia lanceolata plantation ecosystem MICROCLIMATE environmental energy
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Mitigation Options for Methane, Nitrous Oxide and NitricOxide Emissions from Agricultural Ecosystems 被引量:13
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作者 郑循华 王明星 +7 位作者 王跃思 沈壬兴 李晶 J.Heyer M.Koegge H.Papen 金继生 李老土 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2000年第1期83-92,共10页
An experimental study on mitigation of greenhouse gas (CH4, N2O and NO) emission has been conducted in a typical cropping system of Southeast China for 4 years. By simultaneous measurement, the CH4, N2O and NO emissio... An experimental study on mitigation of greenhouse gas (CH4, N2O and NO) emission has been conducted in a typical cropping system of Southeast China for 4 years. By simultaneous measurement, the CH4, N2O and NO emission fluxes from rice-wheat rotation fields, effects of fertilization, water management, temperature and soil moisture were investigated. Temperature, fertilization and water status were found to be the key factors to regulate CH4, N2O and NO emis-sions. Based on the experimental results, some agricultural measures were recommended as techni-cal options to mitigate greenhouse gas emissions from rice-wheat rotation ecosystems. These miti-gation measures are reducing mineral N input, coupling organic manure with chemical fertilizers, applying fertilizers which release available N slowly during periods with intensive plant activity, and applying dry fermented organic manure and well management of water and fertilizer. Key words Mitigation options - Emission - Greenhouse gases - Ecosystems This study was supported by projects “ Experimental and Modeling Study on N2O Emission from the Rice-Wheat Rotation Fields of Southeast China” and “ Experimental and Modeling Study on NO Emission from Croplands” , which were granted by the National Natural Science Foundation of China, the State Key Fundamental Research Project “ Predicting the Future (20–50 years) Trend of Environmental Change in China”, and the project of Chinese Academy of Sciences “ Theory and Methodology on Air Pollution Prediction”.Thanks are due to Professor Zhang Wen, Dr. Bai Jianhui, Mr. Gong Yanbang, Mrs. Luo Dongmei and Mr. Liu Guangren from the Institute of Atmospheric Physics, Chinese Academy of Sciences for their help in experiments. 展开更多
关键词 Mitigation options Emission Greenhouse gases ecosystems
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Differentiation of Soil Fauna Populations in Conventional Tillage and No-Tillage Red Soil Ecosystems 被引量:8
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作者 HU FENG LI HUIXIN and WU SHANMEI(Nanjing Agriculturol University, Nanjing 210095 (China)) 《Pedosphere》 SCIE CAS CSCD 1997年第4期339-348,共10页
In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evalu... In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evaluate their responses to tillage disturbance. Earthworms, macrry and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times, while enchytraeids and nematodes favored CT system, predicting certain adaptability of these animals to plow-disturbed soil environment. On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base (C and N pools) and microflora. The population structure of soil fauna was also affected by tillage treatments. Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and omnivorepredators increased in NT soil. Possible reasons for the differentiation in both size and structure of the fauna population were discussed and the ecological significance involved in these changes was emphasized. 展开更多
关键词 conventional tillage NO-TILLAGE red soil ecosystems soil fauna
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Effects of three coniferous plantation species on plant-soil feedbacks and soil physical and chemical properties in semiarid mountain ecosystems 被引量:6
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作者 Chun Han Yongjing Liu +5 位作者 Cankun Zhang Yage Li Tairan Zhou Salman Khan Ning Chen Changming Zhao 《Forest Ecosystems》 SCIE CSCD 2021年第1期22-34,共13页
Background:Large-scale afforestation can significantly change the ground cover and soil physicochemical properties,especially the soil fertility maintenance and water conservation functions of artificial forests,which... Background:Large-scale afforestation can significantly change the ground cover and soil physicochemical properties,especially the soil fertility maintenance and water conservation functions of artificial forests,which are very important in semi-arid mountain ecosystems.However,how different tree species affect soil nutrients and soil physicochemical properties after afforestation,and which is the best plantation species for improving soil fertility and water conservation functions remain largely unknown.Methods:This study investigated the soil nutrient contents of three different plantations(Larix principis-rupprechtii,Picea crassifolia,Pinus tabuliformis),soils and plant-soil feedbacks,as well as the interactions between soil physicochemical properties.Results:The results revealed that the leaves and litter layers strongly influenced soil nutrient availability through biogeochemical processes:P.tabuliformis had higher organic carbon,ratio of organic carbon to total nitrogen(C:N)and organic carbon to total phosphorus(C:P)in the leaves and litter layers than L.principis-rupprechtii or P.crassifolia,suggesting that higher C:N and C:P hindered litter decomposition.As a result,the L.principis-rupprechtii and P.crassifolia plantation forests significantly improved soil nutrients and clay components,compared with the P.tabuliformis plantation forest.Furthermore,the L.principis-rupprechtii and P.crassifolia plantation forests significantly improved the soil capacity,soil total porosity,and capillary porosity,decreased soil bulk density,and enhanced water storage capacity,compared with the P.tabuliformis plantation forest.The results of this study showed that,the strong link between plants and soil was tightly coupled to C:N and C:P,and there was a close correlation between soil particle size distribution and soil physicochemical properties.Conclusions:Therefore,our results recommend planting the L.principis-rupprechtii and P.crassifolia as the preferred tree species to enhance the soil fertility and water conservation functions,especially in semi-arid regions mountain forest ecosystems. 展开更多
关键词 PLANTATION C:N:P stoichiometry Plant-soil feedbacks Soil physicochemical properties Mountain ecosystems
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Effects of root dominate over aboveground litter on soil microbial biomass in global forest ecosystems 被引量:4
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作者 Yanli Jing Peng Tian +3 位作者 Qingkui Wang Weibin Li Zhaolin Sun Hong Yang 《Forest Ecosystems》 SCIE CSCD 2021年第3期504-512,共9页
Background:Inputs of above-and belowground litter into forest soils are changing at an unprecedented rate due to continuing human disturbances and climate change.Microorganisms drive the soil carbon(C)cycle,but the ro... Background:Inputs of above-and belowground litter into forest soils are changing at an unprecedented rate due to continuing human disturbances and climate change.Microorganisms drive the soil carbon(C)cycle,but the roles of above-and belowground litter in regulating the soil microbial community have not been evaluated at a global scale.Methods:Here,we conducted a meta-analysis based on 68 aboveground litter removal and root exclusion studies across forest ecosystems to quantify the roles of above-and belowground litter on soil microbial community and compare their relative importance.Results:Aboveground litter removal significantly declined soil microbial biomass by 4.9%but root exclusion inhibited it stronger,up to 11.7%.Moreover,the aboveground litter removal significantly raised fungi by 10.1%without altering bacteria,leading to a 46.7%increase in the fungi-to-bacteria(F/B)ratio.Differently,root exclusion significantly decreased the fungi by 26.2%but increased the bacteria by 5.7%,causing a 13.3%decrease in the F/B ratio.Specifically,root exclusion significantly inhibited arbuscular mycorrhizal fungi,ectomycorrhizal fungi,and actinomycetes by 22.9%,43.8%,and 7.9%,respectively.The negative effects of aboveground litter removal on microbial biomass increased with mean annual temperature and precipitation,whereas that of root exclusion on microbial biomass did not change with climatic factors but amplified with treatment duration.More importantly,greater effects of root exclusion on microbial biomass than aboveground litter removal were consistent across diverse forest biomes(expect boreal forests)and durations.Conclusions:These data provide a global evidence that root litter inputs exert a larger control on microbial biomass than aboveground litter inputs in forest ecosystems.Our study also highlights that changes in above-and belowground litter inputs could alter soil C stability differently by shifting the microbial community structure in the opposite direction.These findings are useful for predicting microbe-mediated C processes in response to changes in forest management or climate. 展开更多
关键词 Forest ecosystems soil microorganisms FUNGI LITTER ROOT Carbon input META-ANALYSIS
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Ecological pressures on grassland ecosystems and their conservation strategies in Northern China 被引量:4
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作者 Zhirong Zheng Chaoyang Feng +2 位作者 Shengxing Ye Zhaoyan Diao Shihai Lü 《Chinese Journal of Population,Resources and Environment》 2015年第1期87-91,共5页
In this study,we identified ecological pressures on grassland ecosystems and adaptive countermeasures in Northern China.Our research revealed that the main sources of these pressures included population growth,economi... In this study,we identified ecological pressures on grassland ecosystems and adaptive countermeasures in Northern China.Our research revealed that the main sources of these pressures included population growth,economic development,resources exploitation,and global climate change,with human-related activities being overriding factors.Overgrazing was an important reason for grassland imbalance,causing soil erosion and desertification,especially during the sensitive spring greening phase.In steppe zones,commercial coal mining was destructive to the ecological environment.Regarding long-term strategies,we recommend that policy-makers devote more consideration to a new conceptual approach for transforming grasslands through shifting the focus from die grassland's traditional production functions to meir ecological functions.Applying this concept,adaptive countermeasures should be developed to reduce human impacts based on the environmental capacities of grasslands.Moreover,we recommend the development of environment-friendly industries and reduction of pressures from human activities as effective measures for maintaining the balance between sustainable economic development and grassland conservation.Lastly,we suggest that restoration of degraded grasslands should conform to the principle of natural vegetation to further improve the ecological adaptability of plants and ecosystem stability.This study is expected to provide scientific support for policy-makers engaged in grassland protection. 展开更多
关键词 GRASSLAND ecosystems ECOLOGICAL pressure NORTHERN China CONSERVATION strategy
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Coastal blue carbon ecosystems in China 被引量:5
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作者 Fa-ming Wang Jing-fan Zhang +1 位作者 Si-yuan Ye Ji-hua Liu 《China Geology》 2022年第1期193-194,共2页
1.What are blue carbon ecosystems?Coastal blue carbon ecosystems(BCEs)consists of salt marshes,mangroves,and seagrass bed.Its function as carbon(C)sink is an important pathway to reduce atmospheric carbon dioxide(CO_(... 1.What are blue carbon ecosystems?Coastal blue carbon ecosystems(BCEs)consists of salt marshes,mangroves,and seagrass bed.Its function as carbon(C)sink is an important pathway to reduce atmospheric carbon dioxide(CO_(2))concentration and mitigate global change.Coastal wetlands have a great carbon sequestration capacity. 展开更多
关键词 ecosystems CARBON capacity
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Alpine Ecosystems of Northwest Yunnan,China:an Initial Assessment for Conservation 被引量:4
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作者 Ruth Sherman Renee Mullen +2 位作者 LI Haomin FANG Zhendong WANG Yi 《Journal of Mountain Science》 SCIE CSCD 2007年第3期181-192,共12页
Implementing conservation actions on-the-ground is not a straightforward process,especially when faced with high scientific uncertainty due to limited available information. This is especially acute in regions of the ... Implementing conservation actions on-the-ground is not a straightforward process,especially when faced with high scientific uncertainty due to limited available information. This is especially acute in regions of the world that harbor many unique species that have not been well studied,such as the alpine zone of the Hengduan Mountains of Northwest Yunnan (NWY),a global biodiversity hotspot and site of The Nature Conservancy’s Yunnan Great Rivers Project. We conducted a quantitative,but rapid regional-level assessment of the alpine flora across NWY to provide a broad-based understanding of local and regional patterns of the alpine flora,the first large-scale analysis of alpine biodiversity patterns in this region. Multivariate analyses were used to classify the major plant community types and link community patterns to habitat variables. Our analysis indicated that most species had small distributions and/or small population sizes. Strong patterns emerged with higher diversity in the more northern mountains,but beta diversity was high,averaging only 10% among sites. The ordinations indicated that elevation and geographic location were the dominant environ-mental gradients underlying the differences in the species composition among communities. The high beta diversity across the alpine of these mountains implies that conservation strategies ultimately will require the protection of large numbers of species over a large geographical area. However,prioritiza-tion should be given to areas where potential payoffs are greatest. Sites with high species richness also have a greater number of endemic species,and,by focusing efforts on these sites,conservation investments would be maximized by protecting the greatest number of unique species. 展开更多
关键词 Biodiversity hotspot cluster analysis plant community ecology conservation action GRAZING Hengduan Mountains non-metric multidimensional scaling plant species richness World Heritage Site Yunnan Great Rivers Project(YGRP) alpine ecosystems China
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Dynamic phosphorus budget for lake-watershed ecosystems 被引量:2
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作者 LIU Yong GUO Huai-cheng +3 位作者 WANG Li-jing DAI Yong-li ZHANG Xiu-min LI Zi-hai 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第3期596-603,共8页
Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow... Lake eutrophication caused by excess phosphorus (P) loading from point sources (PS) and nonpoint sources (NPS) is a persistent and serious ecological problem in China. A phosphorus budget, based on material flow analysis(MFA) and system dynamic (SD), is proposed and applied for the agriculture-dominated Qionghai Lake watershed located in southwestern China. The MFA-SD approach will not only cover the transporting process of P in the lake-watershed ecosystems, but also can deal with the changes of P budget due to the dynamics of watershed. P inflows include the fertilizer for agricultural croplands, soil losses, domestic sewage discharges, and the atmospheric disposition such as precipitation and dust sinking. Outflows are consisted of hydrologic export, water resources development, fishery and aquatic plants harvesting. The internal P recycling processes are also considered in this paper. From 1988 to 2015, the total P inflows for Lake Qionghai are in a rapid increase from 35.65 to 78.73 t/a, which results in the rising of P concentration in the lake. Among the total P load 2015, agricultural loss and domestic sewage account for 70.60% and 17.27% respectively, directly related to the rapid social-economic development and the swift urbanization. Future management programs designed to reduce P inputs must be put into practices in the coming years to ensure the ecosystem health in the watershed. 展开更多
关键词 phosphorus budget lake-watershed ecosystems material flow analysis system dynamic
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Changes in stress within grassland ecosystems in the three counties of the source regions of the Yangtze and Yellow Rivers 被引量:2
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作者 Fang, YiPing Qin, DaHe Ding, YongJian 《Journal of Arid Land》 SCIE 2010年第2期116-122,共7页
Based on a database of more than 40 years of second production process and energy flow records for Maduo,Qumalai and Yushu counties,a dynamic model of the stress within grassland ecosys-tems was established using a no... Based on a database of more than 40 years of second production process and energy flow records for Maduo,Qumalai and Yushu counties,a dynamic model of the stress within grassland ecosys-tems was established using a nonlinear regression method for this source regions of the Yangtze and Yel-low Rivers.The results show that dynamic curves of stress within grassland ecosystems in the three coun-ties were in the shape of an inverted 'U' during the period 1965-2007.It also revealed that the variation in actual amount of livestock inventories reflected the general trends of the stress within the grassland eco-systems in the source regions,although there were many other factors for the increase or reduction in grassland ecosystem stress. 展开更多
关键词 the source regions of Yangtze and Yellow Rivers the stress within grassland ecosystems inverted 'U' model DRIVER
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Alternative States of Saline Lake Ecosystems and Development of Salinology 被引量:2
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作者 Nickolai SHADRIN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期434-435,共2页
Modern hydrobiology,mainly,is based on conception,which may be named Conception of unicity of ecosystem stable state(CUESS):Mature ecosystems are stable and in dynamic equilibrium.Ecosystem state fluctuates around
关键词 Alternative States of Saline Lake ecosystems and Development of Salinology LAKE
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Conservation and restoration of degraded ecosystems in arid and semi-arid areas of northwest China 被引量:1
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作者 李俊清 崔国发 《Journal of Forestry Research》 CAS CSCD 2000年第4期237-240,共4页
In "West Development" of China, one of the most important activities is the Natural Forest Protection Program, designed to swiftly convert the focus of management and utilization of the natural forests from ... In "West Development" of China, one of the most important activities is the Natural Forest Protection Program, designed to swiftly convert the focus of management and utilization of the natural forests from a timber orientation towards forest conservation, sustainable management and environmental protection. The project covered almost all the arid and semi-arid regions in Northwest region. Accompanying this great campaign this paper studied the conservation and restoration model of degraded ecosystems in arid and semi-arid lands in Northwest China. The past practices have resulted in considerably natural forest degradation and loss through land conversion (primarily for agriculture), over-harvesting, inadequate reforestation and lack of protection. The consequences have been the loss of soil and water resources, diminished timber production capacity on a sustainable basis, and environmental losses. This paper applied Aronson’s restoration model and proposed the conservation, restoration, re-allocation and preservation program for the implementation of environmental improvement and natural forest conservation. 展开更多
关键词 Degraded ecosystems CONSERVATION RESTORATION
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Compounding effects of human activities and climatic changes on coexistence of oasis-desert ecosystems:Prioritizing resilient decision-making for a riskier world 被引量:1
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作者 XinWei Yin Wei Liu +11 位作者 Meng Zhu JuTao Zhang Qi Feng HaiYang Xi LinShan Yang Tuo Han WenJu Cheng YingQing Su BaiTing Zhang YuanYuan Xue ZeXia Chen LingGe Wang 《Research in Cold and Arid Regions》 CSCD 2023年第5期219-229,共11页
Water-salt balance is critical for the stable coexistence of salt-affected and groundwater-fed oasis-desert ecosystems. Yet, a comprehensive investigation of how soil salinization and groundwater degradation threaten ... Water-salt balance is critical for the stable coexistence of salt-affected and groundwater-fed oasis-desert ecosystems. Yet, a comprehensive investigation of how soil salinization and groundwater degradation threaten the coexistence of oasis-desert ecosystems is still scarce, especially under the compounding effects of human activities and climatic changes. Here, we assessed the impacts of irrigated agriculture on hydrological regimes in oasisdesert systems, investigated the spatio-temporal variations of soil salinization in irrigated cropland, and evaluated the implications of the interplays of soil salinization and groundwater degradation on the coexistence of oasis-desert ecosystems in northwestern China, based on meaningful modelling approaches and comprehensive measurements over 1995–2020. The results showed that the irrigation return flow coefficient decreased sharply from 0.21 ± 0.09 in the traditional irrigation period to 0.09 ± 0.01 in the water-saving irrigation period. The continuous drop in groundwater tables and significant degradation of groundwater quality are occurring throughout this watershed. The eco-environmental flows are reaching to their limit with watershed closures(i.e.,the drainage from the oasis region into the desert region is being weakened or even eliminated), although these progressions were largely hidden by regional precipitation and streamflow variability. The process of salt migration and accumulation across different landscapes in oasis-desert system is being reshaped, and soil salinization in water-saving agricultural irrigated lands is accelerating with a regional average annual growth rate of18%. The vegetation in this watershed is degrading, and anthropogenic disturbance accelerates this trend. Our results highlight that environmental stress adaptation strategies must account for resilience maintenance to avoid accelerating catastrophic transitions in oasis-desert ecosystems. Determining the optimal oasis scales and formulating the best irrigation management plans are effective and resilient decision-making ways to maintain the coexistence relationship of oasis-desert ecosystem in drylands. 展开更多
关键词 Oasis-desert ecosystems Hydrological regimes Soil salinization Vegetation dynamics Resilient decision-making
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Infiltration pattern beneath shrub canopy and interspace grass patches in typical steppe ecosystems of Inner Mongolia, China 被引量:1
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作者 ZHANG Si-yi LI Xiao-yan +1 位作者 PENG Hai-ying ZHANG Zhi-hua 《地球环境学报》 2012年第6期1117-1125,共9页
Water is the most critical factor for controlling die vegetation pattern in arid and semiarid regions.Using a dye-tracing experiment,we analyzed the infiltration pattern beneath shrub canopy and interspace grass patch... Water is the most critical factor for controlling die vegetation pattern in arid and semiarid regions.Using a dye-tracing experiment,we analyzed the infiltration pattern beneath shrub canopy and interspace grass patches in typical steppe ecosystems.The dye coverage,uniform infiltration depth,maximum infiltration depth,total stained area and heterogeneous infiltration stained area were measured by two indices,the maximum infiltration depth index(MIDI)and heterogeneous infiltration index(HII),which were calculated by processing dye-stained photos.The MIDI and HII of soil under shrubs were 1.41±0.14 and 0.29±0.068,respectively,and larger than those of grass soil,1.26±0.14 and0.20±0.076.Using the MIDI,HII,field soil moisture and rainfall data,the infiltration depth and heterogeneous infiltration amount for 26 nature rainfall events were calculated.The results imply that water can infiltrate to a deeper layer beneath shrub canopy than beneath grass patches and that more water infiltration occurs beneath shrub canopy than beneath grass patches.These results are of prime importance for arid and semiarid ecosystems with a limited water supply due to high evaporation and low precipitation. 展开更多
关键词 Infiltration pattern dye-tracing SHRUB grass patches typical steppe ecosystems
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RESEARCH ON THE COMPLICATED DYNAMICAL BEHAVIORS OF NONLINEAR ECOSYSTEMS(Ⅱ) 被引量:1
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作者 昝廷全 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1989年第2期167-173,共7页
This paper is a further study of reference [1]. In this paper, we mainly discuss the complicated dynamical behaviors resulting from a simple one-dimensional model of nonlinear ecosystems: fixed point motion, periodic ... This paper is a further study of reference [1]. In this paper, we mainly discuss the complicated dynamical behaviors resulting from a simple one-dimensional model of nonlinear ecosystems: fixed point motion, periodic motion and chaotic motion etc., and briefly discuss the universality of the complicated dynamical behaviors, which can be described by the first and the second M. Feigenbaun. constants. At last, we discuss the 'one-side lowering phenomenon' due to near unstabilization when the nonlinear ecosystem approaches bifurcation points from unbifurcation side. It is of important theoretical and practical meanings both in the development and utilization of ecological resources ar.d in the design and management of artifilial ecosystems. 展开更多
关键词 RESEARCH ON THE COMPLICATED DYNAMICAL BEHAVIORS OF NONLINEAR ecosystems
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Spatial Variations of Soil Respiration in Arid Ecosystems 被引量:1
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作者 Gang Liu Rei Sonobe Quan Wang 《Open Journal of Ecology》 2016年第4期192-205,共14页
Soil respiration releases a major carbon flux back to atmosphere and thus plays an important role in global carbon cycling. Soil respiration is well known for its significant spatial variation in terrestrial ecosystem... Soil respiration releases a major carbon flux back to atmosphere and thus plays an important role in global carbon cycling. Soil respiration is well known for its significant spatial variation in terrestrial ecosystems, especially in fragile ecosystems of arid land, where vegetation is distributed sparsely and the climate changes dramatically. In this study, soil respiration in three typical arid ecosystems: desert ecosystem (DE), desert-farmland transition ecosystem (TE) and farmland ecosystem (FE) in an arid area of northwestern China were studied for their spatial variations in 2012 and 2013. Along with soil respiration (SR), soil surface temperature (ST), soil moisture (SM) and soil electrical conductivity (ECb) were also recorded to investigate the spatial variations and the correlations among them. The results revealed that averaged soil respiration rate was much lower in DE than those in TE and FE. No single factor could adequately explain the variation of soil respiration, except a negative relationship between soil temperature and soil respiration in FE (P < 0.05). Geostatistical analysis showed that the spatial heterogeneity of soil respiration in DE was insignificant but notably in both TE and FE, especially in FE, which was mainly attributed to the different vegetation or soil moisture characteristics in the three ecosystems. The results obtained in this study will help to provide a better understanding on spatial variations of soil respiration and soil properties in arid ecosystems and also on macroscale carbon cycling evaluations. 展开更多
关键词 Soil Respiration Spatial Variation Arid ecosystems GEOSTATISTICS TEMPERATURE MOISTURE
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Emergy evaluation of the artificial forest ecosystems in the watershed of Miyun Reservoir:a case study for ecosystems valuation and environmental management 被引量:1
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作者 Hu Yanxia Zhou Liandi +1 位作者 Dong Xiaobin Yan Maochao 《Ecological Economy》 2007年第4期381-392,共12页
To build the artificial forest ecosystem is the major eco-economic development model in the watershed of Miyun Reservoir. It is very important to evaluate the benefits of those ecosystems. Emergy theories are very hel... To build the artificial forest ecosystem is the major eco-economic development model in the watershed of Miyun Reservoir. It is very important to evaluate the benefits of those ecosystems. Emergy theories are very helpful for us to establish a science-based assessment framework. Emergy evaluation of the artificial forest ecosystems in the watershed of Miyun Reservoir is used to asses the relative values of several ecological functions (sometimes called ecosystem services) and main ecosystem storages (sometimes called natural capital). The main driving energies, internal processes and storages are evaluated. The main functions, including transpiration, GPP and infiltration, are evaluated, which are 609em$/ha/yr, 6,245em$/ha/yr and 340em$/ha/yr respectively. The total values of major environmental services are 4,683em$/ha/yr in the artificial forest ecosystem. The main storages of natural capital including live biomass, soil moisture, organic matter, underground water and landform are estimated, which are 112,028em$/ha, 9em$/ha, 40,718em$/ha, 34em$/ha and 6,400,514em$/ha respectively. The largest value is landform, which accounts for 97.7% of these calculated total emdollar values. The concept of replacement value is explored using the emergy values of both ecosystem services and natural capital. The total calculated replacement values are 302,160em$/ha. 展开更多
关键词 Artificial forest ecosystems Emergy evaluation Environmental services Natural capital
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