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The importance of terrestrial carbon in supporting molluscs in the wetlands of Poyang Lake

Chinese Journal of Oceanology and Limnology 2017年第4期35卷 825-832页

作者：张欢于秀波王玉玉徐军 Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Chinese Academy of Sciences College of Nature Conservation Beijing Forestry University Institute of Hydrobiology Chinese Academy of Sciences

Allochthonous organic matter plays an important role in nutrient cycling and energy mobilization in freshwater ecosystems. However, the subsidies of this carbon source in floodplain ecosystems have not yet well understood. We used a Bayesian mixing model and stable isotopes （613C and 815N） of primary food resources and dominant molluscs species, to estimate the relative importance of allochthonous carbon sources for consumers in a representative sub-lake of Poyang Lake during a prolonged dry season. Our study inferred that terrestrial-derived carbon from Carex spp. could be the primary contributor to snails and mussels in Dahuchi Lake. The mean percentage of allochthonous food resources accounted for 35%- 50% of the C incorporated by these consumers. Seston was another important energy sources for benthic consumers. However, during the winter and low water-level period, benthic algae and submerged vegetation contributed less carbon to benthic consumers. Our data highlighted the importance of terrestrial organic carbon to benthic consumers in the wetlands of Poyang Lake during the prolonged dry period. Further, our results provided a perspective that linkages between terrestrial and aquatic ecosystems might be facilitated by wintering geese via their droppings.

关键词： allochthonous Carex spp. molluscs floodplain wetland stable isotope analysis Poyang Lake

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Off-farm employment,agriculture production activities,and household dietary diversity in environmentally and economically vulnerable areas of Asia

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Journal of Integrative Agriculture 2024年第2期23卷 359-373页

作者： Yunli Bai Xuanye Zeng Chao Fu Linxiu Zhang Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China United Nations Environment Programme-International Ecosystem Management Partnership(UNEP-IEMP) Beijing 100101China University of Chinese Academy of Sciences Beijing 100101China

Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero *** study aims to investigate the role of off-farm employment in improving dietary diversity through substitution effect and complementary effect with agricultural production activities and income *** study adopts Poisson/Tobit/Probit/OLS regressions and the instrument variable method based on the primary survey data collected among 1,282 households at 12 sites in environmentally and economically vulnerable areas of China,Nepal,Cambodia,Thailand,and Myanmar in *** results show that off-farm employment is positively associated with household dietary diversity and the consumption of flesh meat,fish and other aquatic animals,fruits,and milk and dairy products,which are rich in protein and *** results of mechanism analysis show that off-farm employment contributes to household dietary diversity by improving crop diversity,especially for poor households,boosting the probability of livestock raising for households with the middle one-third disposal income,and increasing household *** positive association between off-farm employment and household dietary diversity is much higher for households with the bottom one-third disposal income,low illiteracy,and from upper-middle income *** findings imply that off-farm employment does play a vital role in achieving multiple benefits of poverty alleviation,malnutrition reduction,and agrobiodiversity conservation in environmentally and economically vulnerable ***,it may enlarge the gaps in dietary diversity between households with low human capital and from low and lower-middle income countries and those with high human capital and from middle-high countries.

关键词： off-farm employment dietary diversity income effect substitution effect complementary effect

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Effect of experimental warming on soil respiration under conventional tillage and no-tillage farmland in the North China Plain

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Journal of Integrative Agriculture 2017年第4期16卷 967-979页

作者： TU Chun LI Fa-dong QIAO Yun-feng ZHU Nong GU Cong-ke ZHAO Xin Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101P.R.China University of Chinese Academy of Science Beijing 100049P.R.China

Understanding the response of soil respiration to global warming in agro-ecosystem is crucial for simulating terrestrial carbon （C） cycle. We conducted an infrared warming experiment under conventional tillage （CT） and no-tillage （NT） farmland for winter wheat and summer maize rotation system in North China Plain （NCP）. Treatments include CT with and without warming （CTW and CTN）, NT with and without warming （NTW and NTN）. The results indicated that warming had no sig- nificant effect on soil moisture in irrigated farmland of NCP （P〉0.05）. The elevated average soil temperature of 1.1-116℃ in crop growing periods could increase annual soil CO2 emission by 10.3% in CT filed （P〉0.05）, but significantly increase it by 12.7% in NT field （P〈0.05）, respectively. The disturbances such as plowing, irrigation and precipitation resulted in the obvious soil CO2 emission peaks, which contributed 36.6-40.8% of annual soil cumulative CO2 emission. Warming would enhance these soil CO2 emission peaks; it might be associated with the warming-induced increase of autotrophic respiration and heterotrophic respiration. Compared with un-warming treatments, dissolved organic carbon （DOC） and soil microbial biomass carbon （MBC） in warming treatments were significantly increased by 11.6-23.4 and 12.9-23.6%, respectively, indicating that the positive responses of DOC and MBC to warming in both of two tillage systems. Our study highlights that climate warming may have positive effects on soil C release in NCP in association with response of labile C substrate to warming.

关键词： global warming conventional tillage no-tillage soil respiration dissolved organic carbon soil microbial biomasscarbon

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Analyzing the velocity of vegetation phenology over the Tibetan Plateau using GIMMS NDVI3G data

Analyzing the velocity of vegetation phenology over the Tibe...

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2018 ISPRS TC III Mid-Term Symposium on Developments, Technologies and Applications in Remote Sensing

作者： Zhou, Y.K. Key Laboratory of Ecosystem Network Observation and Modelling IGSNRR CAS Beijing100101 China

Global environmental change is rapidly altering the dynamics of terrestrial vegetation, and phenology is a classic proxy to detect the response of vegetation to the changes. On the Tibetan Plateau, the earlier spring and delayed autumn vegetation phenology is widely reported. Remotely sensed NDVI can serve as a good data source for vegetation phenology study. Here GIMMS NDVI3g data was used to detect vegetation phenology status on the Tibetan Plateau. The spatial and temporal gradients are combined to depict the velocity of vegetation expanding process. This velocity index represents the instantaneous local velocity along the Earth's surface needed to maintain constant vegetation condition. This study found that NDVI velocity show a complex spatial pattern. A considerable number of regions display a later starting of growing season (SOS) and earlier end of growing season (EOS) reflected by the velocity change, particularly in the central part of the plateau. Nearly 74% vegetation experienced a shortened growing season length. Totally, the magnitude of the phenology velocity is at a small level that reveals there is not a significant variation of vegetation phenology under the climate change context. © Authors 2018. CC BY 4.0 License.

关键词： Velocity

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A R-shiny based phenology analysis system and case study using digital camera dataset

A R-shiny based phenology analysis system and case study usi...

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2018 ISPRS TC III Mid-Term Symposium on Developments, Technologies and Applications in Remote Sensing

作者： Zhou, Y.K. Key Laboratory of Ecosystem Network Observation and Modelling IGSNRR CAS Beijing100101 China

Accurate extracting of the vegetation phenology information play an important role in exploring the effects of climate changes on vegetation. Repeated photos from digital camera is a useful and huge data source in phonological analysis. Data processing and mining on phenological data is still a big challenge. There is no single tool or a universal solution for big data processing and visualization in the field of phenology extraction. In this paper, we proposed a R-shiny based web application for vegetation phenological parameters extraction and analysis. Its main functions include phenological site distribution visualization, ROI (Region of Interest) selection, vegetation index calculation and visualization, data filtering, growth trajectory fitting, phenology parameters extraction, etc. the long-term observation photography data from Freemanwood site in 2013 is processed by this system as an example. The results show that: (1) this system is capable of analyzing large data using a distributed framework;(2) The combination of multiple parameter extraction and growth curve fitting methods could effectively extract the key phenology parameters. Moreover, there are discrepancies between different combination methods in unique study areas. Vegetation with single-growth peak is suitable for using the double logistic module to fit the growth trajectory, while vegetation with multi-growth peaks should better use spline method. © Authors 2018. CC BY 4.0 License.

关键词： Vegetation

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The Altitudinal Belts of Subalpine Virgin Forest on *** Simulated by a Succession Model

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Journal of Mountain Science 2014年第6期11卷 1560-1570页

作者： CHENG Gen-wei SUN Jian SHA Yu-kun FAN Ji-hui Key Laboratory of Mountain Surface Process and Ecological Regulation Institute of Mountain Hazard and EnvironmentChinese Academy of Sciences Synthesis Research Centre of Chinese Ecosystem Research Network Key Laboratory of Ecosystem Network Observation and Modelling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences

How to accurately simulate the distribution of forest species based upon their biological attributes has been a traditional biogeographical *** gap models are very useful tools for examining the dynamics of forest succession and revealing the species structure of *** the present study,the GFSM(Gongga Forest Succession Model) was developed and applied to simulate the distribution,composition and succession process of forests in 100 m elevation *** results indicate that the simulated results of the tree species,quantities of the different types of trees,tree age and differences in DBH(diameter at breast height) composition were in line with the actual situation from 1400 to 3700 MASL(meters above sea level) on the eastern slope of ***,the dominant species in the simulated results were the same as those in the surveyed ***,the GFSM model can best simulate the features of forest dynamics and structure in the natural conditions of *** work provides a new approach to studying the structure and distribution characteristics of mountain ecosystems in varied ***,the results of this study suggest that the biogeochemistry mechanism model should be combined with the forestsuccession model to facilitate the ecological model in simulating the physical and chemical processes involved.

关键词： Subalpine forests Altitudinal belts Succession processes Forest gap model

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Carbon budget and balance critical processes of the regional landwater-air interface:Indicating the earth system’s carbon neutrality

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Science China Earth Sciences 2022年第5期65卷 773-782页

作者： Yang GAO Shuoyue WANG Yao LU Jianbao LIU Sidan LYU Kun SUN Junjie JIA Zhaoxi LI Guirui YU Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Alpine Ecology Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Regional processes on land-water-air interface carbon(C)budget and balance that interconnect the land and sea are in fact C neutrality critical processes within the earth *** is therefore essential to quantitatively analyze synergistic landwater-air interface C transport and C exchange processes to gain a deep understanding of the important role that terrestrial ecosystems play in“missing C sink”.This paper systematically analyzes global land-water-air interface C migration processes as well as C budget changes and associated impact *** also investigates the important role that these C budgets and C cycling processes play in inland water bodies,respective to C budgets at the land-water-air ***,this study reveals the regulatory mechanisms of land-water-air interface C budgets and balances under a background of global climate *** also quantitatively evaluates the status of China’s regional land-sea-air interface C budgets as well as the C sequestration potential of its lake ***,this study concludes that the explicit quantification of anthropogenic activity impacts on land-water-air interface C transport and exchange processes is of great significance to global C balances and C neutrality.

关键词： C budget C balance C neutrality Critical zone Land-water-air interface exchange Land-sea coordination

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Effects of Temperature and Moisture on Soil Organic Matter Decomposition Along Elevation Gradients on the Changbai Mountains, Northeast China

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Pedosphere 2016年第3期26卷 399-407页

作者： WANG Dan HE Nianpeng WANG Qing LV Yuliang WANG Qiufeng XU Zhiwei ZHU Jianxing Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 (China) Agricultural University of Anhui Hefei 230036 (China) College of Geographical Science Southwest University Chongqing 400715 (China)

Decomposition of soil organic matter(SOM) is of importance for CO_2 exchange between soil and atmosphere and soil temperature and moisture are considered as two important factors controlling SOM decomposition. In this study, soil samples were collected at 5 elevations ranging from 753 to 2 357 m on the Changbai Mountains in Northeast China, and incubated under different temperatures(5, 10, 15, 20, 25, and 30?C) and soil moisture levels(30%, 60%, and 90% of saturated soil moisture) to investigate the effects of both on SOM decomposition and its temperature sensitivity at different elevations. The results showed that incubation temperature(F = 1 425.10, P < 0.001), soil moisture(F = 1 327.65, P < 0.001), and elevation(F = 1 937.54, P < 0.001) all had significant influences on the decomposition rate of SOM. The significant effect of the interaction of incubation temperature and soil moisture on the SOM decomposition rate was observed at all the 5 sampling elevations(P < 0.001). A two-factor model that used temperature and moisture as variables fitted the SOM decomposition rate well(P < 0.001) and could explain 80%–93% of the variation of SOM decomposition rate at the 5 elevations. Temperature sensitivity of SOM decomposition, expressed as the change of SOM decomposition rate in response to a 10?C increase in temperature(Q_(10)), was significantly different among the different elevations(P < 0.01), but no apparent trend with elevation was discernible. In addition, soil moisture and incubation temperature both had great impacts on the Q_(10) value(P < 0.01), which increased significantly with increasing soil moisture or incubation temperature. Furthermore, the SOM decomposition rate was significantly related to soil total Gram-positive bacteria(R^2= 0.33, P < 0.01) and total Gram-negative bacteria(R^2= 0.58, P < 0.001). These findings highlight the importance of soil moisture to SOM decomposition and its Q_(10) value,which needs to be emphasized under warming climate sce

关键词： Gram-negative bacteria Gram-positive bacteria saturated soil moisture soil respiration temperature sensitivity warming climate scenarios

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Spatio-temporal analysis of the human footprint in the Hengduan Mountain region:Assessing the effectiveness of nature reserves in reducing human impacts

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Journal of Geographical Sciences 2020年第7期30卷 1140-1154页

作者： YIN Le DAI Erfu ZHENG Du WANG Yahui MA Liang TONG Miao Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Lhasa Plateau Ecosystem Research Station Key Laboratory of Ecosystem Network Observation and ModelingInstitute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Mapping the human footprint(HF)makes it possible to quantify human influence,which has had an unprecedented impact on the global *** five categories of human pressure data,this study mapped the HF of the Hengduan Mountain region and assessed the effectiveness of nature reserves in reducing human *** results showed that the HF of the Hengduan Mountain region was generally higher in the south and lower in the *** HF increased by 11.24%over the past 25 years,with faster growth in the *** HF growth rate in nature reserves was much lower than that across the region,which indicated that nature reserves played an important role in reducing the impact of human pressure.A study of Baimaxueshan nature reserve found that establishing nature reserves could effectively reduce the impact of human activities,and no"leakage"*** growth was an important reason for the increased HF in nature *** development of ecotourism in nature reserves must be based on ecological *** the long-term monitoring,evaluation,and management of nature reserves is a basic requirement for their long-term development.

关键词： human influence human footprint nature reserves effectiveness

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Attribution analysis for water yield service based on the geographical detector method:A case study of the Hengduan Mountain region

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Journal of Geographical Sciences 2020年第6期30卷 1005-1020页

作者： DAI Erfu WANG Yahui Lhasa Plateau Ecosystem Research Station Key Laboratory of Ecosystem Network Observation and Mod-elingInstitute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

ecosystem services,which include water yield services,have been incorporated into decision processes of regional land use planning and sustainable *** pattern characteristics and identification of factors that influence water yield are the basis for decision ***,there are limited studies on the driving mechanisms that affect the spatial heterogeneity of ecosystem *** this study,we used the Hengduan Mountain region in southwest China,with obvious spatial heterogeneity,as the research *** water yield module in the InVEST software was used to simulate the spatial distribution of water ***,quantitative attribution analysis was conducted for various geomorphological and climatic zones in the Hengduan Mountain region by using the geographical detector *** factors,such as climate,topography,soil,vegetation type,and land use type and pattern,were taken into consideration for this *** key findings were ***,water yield spatial heterogeneity is influenced most by climate-related factors,where precipitation and evapotranspiration are the dominant ***,the relative importance of each impact factor to the water yield heterogeneity differs significantly by geomorphological and climatic *** flat areas,the influence of evapotranspiration is higher than that of *** relief increases,the importance of precipitation increases and eventually,it becomes the most influential *** is the most influential factor in a plateau climate zone,while in the mid-subtropical zone,precipitation is the main controlling ***,land use type is also an important driving force in flat ***,more attention should be paid to urbanization and land use planning,which involves land use changes,to mitigate the impact on water yield spatial *** fourth finding was that a risk detector showed that Primarosol and Anthropogenic soil areas,shrub areas,and areas with sl

关键词： water yield service Hengduan Mountain region InVEST software geographical detector attribution analysis

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