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Different responses of soil respiration and its components to nitrogen and phosphorus addition in a subtropical secondary forest

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Forest ecosystems 2021年第3期8卷 491-503页

作者： Junjun Zhang Yong Li Jinsong Wang Weinan Chen Dashuan Tian Shuli Niu Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Beijing Key Laboratory of Wetland Services and Restoration Institute of Wetland ResearchChinese Academy of ForestryBeijing 100091China Department of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

Background:Nitrogen(N)and phosphorus(P)deposition have largely affected soil respiration(Rs)in forest ***,few studies have explored how N and P individually or in combination to influence Rs and its components(autotrophic respiration,Ra;heterotrophic respiration,Rh),especially in highly P-limited subtropical *** address this question,we conducted a field manipulation experiment with N and/or P addition in a 50-year-old subtropical secondary ***:We found that N addition on average reduced Rs,Ra,and Rh by 15.2%,15%,and 11.7%,respectively during 2-year field study.P addition had an inconsistent effect on Ra,with Ra increasing by 50.5%in the first year but reducing by 26.6%in the second ***,P addition on average decreased Rh by 8.9%–30.9%and Rs by 6.7%–15.6%across 2 *** contrast,N and P co-addition on average increased Rs,Ra,and Rh by 1.9%,7.9%,and 2.1%during the experimental *** Rs and Rh were significantly correlated with soil temperature,their temperature sensitivities were not significantly changed by *** was predominantly regulated by soil nitrogen availability(NH4+and NO3−),soil dissolved organic carbon(DOC),and enzyme activities,while the variation in Rh was mainly attributable to changes in soil microbial community composition and soilβ-D-Cellubiosidase(CB)andβ-Xylosidase(XYL)***:Our findings highlight the contrasting responses of Rs and its components to N or P addition against N and P co-addition,which should be differentially considered in biogeochemical models in order to improve prediction of forest carbon dynamics in the context of N and P enrichment in terrestrial ecosystems.

关键词： Nitrogen deposition Phosphorus enrichment Heterotrophic respiration Autotrophic respiration Enzyme activities Microbial community composition

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Responses of gross primary productivity to different sizes of precipitation events in a temperate grassland ecosystem in Inner Mongolia, China

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Journal of Arid Land 2016年第1期8卷 36-46页

作者： GUO Qun LI Shenggong HU Zhongmin ZHAO Wei YU Guirui SUN Xiaomin LI Linghao LIANG Naishen BAI Wenming Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Global Carbon Cycle Research Section Center for Global Environmental Research National Institute for Environmental Studies

Changes in the sizes of precipitation events in the context of global climate change may have profound impacts on ecosystem productivity in arid and semiarid grasslands. However, we still have little knowledge about to what extent grassland productivity will respond to an individual precipitation event. In this study, we quantified the duration, the maximum, and the time-integrated amount of the response of daily gross primary productivity (GPP) to an individual precipitation event and their variations with different sizes of precipitation events in a typical temperate steppe in Inner Mongolia, China. Results showed that the duration of GPP-response (τ_R) and the maximum absolute GPP-response (GPP_max) increased linearly with the sizes of precipitation events (P_es), driving a corresponding increase in time-integrated amount of the GPP-response (GPP_total) because variations of GPPtotal were largely explained by τ_R and GPP_max. The relative contributions of these two parameters to GPP_total were strongly P_es-dependent. The GPP_max contributed more to the variations of GPP_total when P_es was relatively small (<20 mm), whereas τ_R was the main driver to the variations of GPP_total when P_es was relatively large. In addition, a threshold size of at least 5 mm of precipitation was required to induce a GPP-response for the temperate steppe in this study. Our work has important implications for the modeling community to obtain an advanced understanding of productivity-response of grassland ecosystems to altered precipitation regimes.

关键词： precipitation event grassland gross primary productivity global climate change precipitation regime

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Spatial variability of soil water content and related factors across the Hexi Corridor of China

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Journal of Arid Land 2019年第1期11卷 123-134页

作者： LI Xiangdong SHAO Ming'an ZHAO Chunlei JIA Xiaoxu State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water Resources College of Natural Resources and Environment University of Chinese Academy of Sciences Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Soil water content(SWC) is a key factor limiting ecosystem sustainability in arid and semi-arid areas of the Hexi Corridor of China, which is characterized by an ecological environment that is vulnerable to climate change. However, there is a knowledge gap regarding the large-scale spatial distribution of SWC in this region. The specific objectives of this study were to determine the spatial distribution patterns of SWC across the Hexi Corridor and identify the factors responsible for spatial variation of SWC at a regional scale. This study collected and analyzed SWC in the 0–100 cm soil profile from 109 field sampling sites(farmland, grassland and forestland) across the Hexi Corridor in 2017. We selected 17 factors, including land use, topography(latitude, longitude, elevation, slope gradient, and slope aspect), soil properties(soil clay content, soil silt content, soil bulk density, saturated hydraulic conductivity, field capacity, and soil organic carbon content), climate factors(mean annual precipitation, potential evaporation, and aridity index), plant characteristic(vegetation coverage) and planting pattern(irrigation or rain-fed), as possible environmental variables to analyze their effects on SWC. The results showed that SWC was 0.083(±0.067) g/g in the 0–100 cm soil profile and decreased in the order of farmland, grassland and forestland. The SWC in the upper soil layers(0–20, 20–40 and 40–60 cm) had obvious difference when the mean annual precipitation differed by 200 mm. The SWC decreased from southeast to northwest following the same pattern as precipitation, and had a moderate to strong spatial dependence in a large effective range(75–378 km). The SWC showed a similar distribution and had no significant difference between soil layers in the 0–100 cm soil profile. The principal component analysis showed that the mean annual precipitation, geographical position(longitude and latitude) and soil properties(soil bulk density and soil clay content) were the m

关键词： soil water content spatial variability geostatistical analysis soil clay content Hexi Corridor

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Off-farm income promotes energy transition in the Pan-Third Pole cross-national region

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Advances in Climate Change Research 2023年第5期14卷 798-809页

作者： Xiao-Qi ZHENG Xiang-Bo XU Chang LI Chao FU Zhao-Yuan FAN School of Economics Nanjing University of Posts and TelecommunicationsNanjing 210023China 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 100049China

The Pan-Third Pole region comprises multiple nations affected by climate vulnerability and energy inequality,wherein promoting energy transitions in rural households would provide a path to combat climate *** the factors that drive rural household energy consumption and the transition is *** study performed a micro-survey of 1060 rural households in five countries in the Pan-Third Pole region and empirically analyzed the relationships between off-farm income,energy consumption,and energy *** off-farm income of rural households was found to have a significantly positive effect(p<0.01)on energy expenditure,indicating that energy expenditure increased with increasing off-farm ***-farm income has a significantly positive effect(p<0.01)on the proportion of commercial energy but a significantly negative effect on the proportion of noncommercial *** results indicate that increasing off-farm income can adjust the energy consumption structure of rural ***,a robustness check by substituting independent variables,instrumental variable method(IV),and propensity score matching method(PSM)provided strong evidence to prove the robustness of the *** heterogeneity analysis showed that the effects of off-farm income on energy expenditure and transitions differed among countries,off-farm income had no significant impact on energy expenditure in Cambodia and Myanmar,but it worked for China,Nepal,and ***,policy implications are proposed to promote energy transition in the Pan-Third pole region:providing more full-time or part-time off-farm employment opportunities,employment assistance or skill training by local governments;increasing the pace of infrastructure construction to solve energy inaccessibility;multiple measures to promote the education and environmental knowledge.

关键词： Off-farm income Rural household Energy consumption Energy transition Pan-Third Pole region

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Biogeographical patterns of arbuscular mycorrhizal fungi diversity in China’s grasslands

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Journal of Geographical Sciences 2021年第7期31卷 965-976页

作者： TENG Jialing TIAN Jing YU Guirui Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China College of Resources and Environmental Sciences Key Laboratory of Plant-Soil InteractionsMinistry of EducationChina Agricultural UniversityBeijing 100193China

Arbuscular mycorrhizal fungi(AMF)are universally mutualistic symbionts that colonize the fine roots of most vascular ***,the biogeographical patterns and driving factors of AMF diversity of plant roots in grasslands are not well *** this study,we used high-throughput sequencing techniques and bioinformatics to evaluate the AMF richness of 333 individual plant roots in 21 natural grassland ecosystems in northern China,including the Loess Plateau(LP),the Mongolian Plateau(MP),and the Tibetan Plateau(TP).The AMF richness showed a significant parabolic trend with increasing *** regional situations,the AMF richness in the grasslands of the MP(60.4±1.47)was significantly higher than those of the LP(46.4±1.43)and TP(44.3±1.64).Plant traits(including plant families,genera,and functional groups)explained the most variation in the AMF richness across China's grasslands,followed by energy and water;soil properties had the least *** results showed the biogeographical patterns of the AMF richness and the underlying dominant factors,providing synthetic data compilation and analyses in the AMF diversity in China's grasslands.

关键词： arbuscular mycorrhizal fungi biogeography grassland ecosystems northern China

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Spatial distribution of water-active soil layer along the south-north transect in the Loess Plateau of China

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Journal of Arid Land 2019年第2期11卷 228-240页

作者： ZHAO Chunlei SHAO Ming'an JIA Xiaoxu HUANG Laiming ZHU Yuanjun Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences College of Resources and Environment University of Chinese Academy of Sciences State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Northwest A&F University College of Natural Resources and Environment Northwest A&F University

Soil water is an important composition of water recycle in the soil-plant-atmosphere ***, intense water exchange between soil-plant and soil-atmosphere interfaces only occurs in a certain layer of the soil profile. For deep insight into water active layer(WAL, defined as the soil layer with a coefficient of variation in soil water content >10% in a given time domain) in the Loess Plateau of China,we measured soil water content(SWC) in the 0.0–5.0 m soil profile from 86 sampling sites along an approximately 860-km long south-north transect during the period 2013–2016. Moreover, a dataset contained four climatic factors(mean annual precipitation, mean annual evaporation, annual mean temperature and mean annual dryness index) and five local factors(altitude, slope gradient, land use, clay content and soil organic carbon) of each sampling site was obtained. In this study, three WAL indices(WALT(the thickness of WAL), WAL-CV(the mean coefficient of variation in SWC within WAL) and WALSWC(the mean SWC within WAL)) were used to evaluate the characteristics of WAL. The results showed that with increasing latitude, WAL-T and WAL-CV increased firstly and then decreased. WAL-SWC showed an opposite distribution pattern along the south-north transect compared with WAL-T and *** WAL-T of the transect was 2.0 m, suggesting intense soil water exchange in the 0.0–2.0 m soil layer in the study area. Soil water exchange was deeper and more intense in the middle region than in the southern and northern regions, with the values of WAL-CV and WAL-T being 27.3% and 4.3 m in the middle region,respectively. Both climatic(10.1%) and local(4.9%) factors influenced the indices of WAL, with climatic factors having a more dominant effect. Compared with multiple linear regressions, pedotransfer functions(PTFs) from arti?cial neural network can better estimate the WAL indices. PTFs developed by artificial neural network respectively explained 86%, 81% and 64% of the total

关键词： water active layer soil water content redundancy analysis pedotransfer function artificial neural network Loess Plateau

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Spatial pattern of plant species diversity and the influencing factors in a Gobi Desert within the Heihe River Basin, Northwest China

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Journal of Arid Land 2017年第3期9卷 379-393页

作者： ZHANG Pingping SHAO Ming'an ZHANG Xingchang Institute of Soil and Water Conservation Northwest A&F University State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationChinese Academy of Sciences and Ministry of Water Resources Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Understanding the spatial pattern of plant species diversity and the influencing factors has important implications for the conservation and management of ecosystem biodiversity. The transitional zone between biomes in desert ecosystems, however, has received little attention in that regard. In this study, we conducted a quantitative field survey （including 187 sampling plots） in a 40-km2 study area to determine the spatial pattern of plant species diversity and analyze the influencing factors in a Gobi Desert within the Heihe River Basin, Northwest China. A total of 42 plant species belonging to 16 families and 39 genera were recorded. Shrub and semi-shrub species generally represented the major part of the plant communities （covering 90% of the land surface）, while annual and perennial herbaceous species occupied a large proportion of the total recorded species （71%）. Patrick richness index （R）, Shannon-Wiener diversity index （H）, Simpson＇s dominance index （D）, and Pielou＇s evenness index （I） were all moderately spadaUy variable, and the variability increased with increasing sampling area. The semivariograms for R and H＇ were best fitted with Gaussian models while the semivariograms for D andJ were best fitted with exponential models. Nugget-to-still ratios indicated a moderate spatial autocorrelation for R, H＇, and D while a strong spatial autocorrelation was observed for J. The spatial patterns of R and H＇ were closely related to the geographic location within the study area, with lower values near the oasis and higher values near the mountains. However, there was an opposite trend for D. R, H＇, and D were significantly correlated with elevation, soil texture, bulk density, saturated hydraulic conductivity, and total porosity （P〈0.05）. Generally speaking, locations at higher elevations tended to have higher species richness and diversity and the higher elevations were characterized by higher values in sand and gravel contents, bulk density, and saturated hydraul

关键词： species diversity spatial heterogeneity environmental factors Gobi Desert transitional zone

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Fertilization regulates the response of wheat yield to interannual temperature variation in North China

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Journal of Plant Ecology 2015年第5期8卷 523-529页

作者： Zhenzhong Sun Anping Chen Junhua Ma Chune He Zhu Ouyang Zhenrong Tian Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesNo.11 of Datun RoadChaoyang DistrictBeijing 100101China Department of Ecology and Evolutionary Biology Princeton UniversityPrincetonNJ 08544USA

Aims understanding the effect of long-term fertilization on the sensitivity of grain yield to temperature changes is critical for accurately assess-ing the impact of global warming on crop *** this study,we aim to assess the impacts of temperature changes on grain yields of winter wheat(Triticum aestivum l.)under different fertilization treatments in a long-term manipulative experiment in North *** We measured grain yields of winter wheat under four fertilization treatments at the Yucheng Comprehensive Experimental station each year from 1993 to *** also measured air temperature at 0200,0800,1400 and 2000 h each day since 1 January *** then used the first-difference method and simple linear regres-sion models to examine the relationship of crop yield changes to mean air temperature,mean daytime and nighttime air temperature in crop growing *** Findings We found that increases in mean daily temperature,mean day-time temperature and mean nighttime temperature each had a positive impact on the grain yield of winter *** yield increased by 16.7-85.6%for winter wheat in response to a 1°C increase in growing season mean daily *** wheat yield was more sensitive to variations of nighttime temperature than to that of daytime *** observed temperature impacts also varied across different fertilization *** fertilization significantly enhanced grain yields for winter wheat under a warming *** plots treated with nitrogen and phosphorous balanced fertilization(NPK-and NP-treated plots)were more responsive to temperature changes than those *** report provides direct evidence of how temperature change impacts grain yields under different fertiliza-tion treatments,which is useful for crop management in a chang-ing global climate.

关键词： grain yield fertilization daytime temperature nighttime temperature winter wheat

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Grazing alters environmental control mechanisms of evapotranspiration in an alpine meadow of the tibetan Plateau

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Journal of Plant Ecology 2019年第5期12卷 834-845页

作者： Tingting An Mingjie Xu Tao Zhang Chengqun Yu Yingge Li Ning Chen Jiaxing Zu Junxiang Li Juntao Zhu Yi Sun Tingting Zhao Guirui Yu College of Agronomy Shenyang Agricultural UniversityShenyang 110866China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Peking University Shenzhen Graduate School Shenzhen 518055China

Aims Evapotranspiration(Et)is an important component of the terrestrial water cycle and is easily affected by external disturbances,such as climate change and *** Et responses to grazing is instructive for determining grazing activity and informative for understanding the water *** this study utilized 2 years(2014 and 2017)of eddy covariance data to test how grazing regulated Et for an alpine meadow ecosystem on the tibetan Plateau(tP)by path *** Findings Radiation dominated Et with a decision coefficient of 64-74%.the soil water content(SWc)worked as the limiting factor in the fenced ***,in the grazing site,the limiting factor was the vapor pressure deficit(VPD).Grazing had large effects on Et because it greatly affected the water *** SWc and VPD were enhanced by 14.63%and 4.36%in the grazing site,***,sufficient water was supplied to Et,especially during drought,and strengthened the transpiration *** a result,a favorable micrometeorological environment was created for *** shifted the limiting factor of Et from the SWc to VPD,which weakened the limiting effect of the water conditions on Et and advanced the Et peak *** addition,grazing altered the compositions of Et by changing the community structure,which directly resulted in an increased *** summary,grazing enhanced Et through altering the community structure and micrometeorological *** findings of this study further improve our understanding of the driving mechanisms of grazing on Et and will improve our predictions for the global water cycle.

关键词： grazing evapotranspiration environmental factors alpine meadow path analysis

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Characteristics of Dried Soil Layers Under Apple Orchards of Different Ages and Their Applications in Soil Water Managements on the Loess Plateau of China

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Pedosphere 2015年第4期25卷 546-554页

作者： WANG Yunqiang SHAO Mingan LIU Zhipeng ZHANG Chencheng State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences & Ministry of Water Resources Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

Negative soil water balance （i.e., water input 〈 water output） can lead to soil desiccation and subsequently the occurrence of a dried soil layer （DSL）. The DSLs are generally studied at a specific sampling depth （e.g., 500 cm）, and the actual extent of DSLs remains unknown due to the challenge of collecting deep soil samples. To investigate the characteristics of actual DSLs under different ages of apple orchards and ascertain the optimal age of apple orchards for avoiding/controlling the formation of DSLs, soil samples were collected to a depth of 1800 cm under apple orchards of different ages in Changwu on the Loess Plateau of China. As the ages increased, soil water content （SWC） and mean SWC in DSLs showed an overall decreasing trend, whereas while DSL thickness and the quantity of water deficit （QWD） in DSLs demonstrated an increasing trend. The DSL was the thickest （1 600 cm） under the 17-yeax-old orchard, the forming velocity of DSL thickness was the highest at the apple tree growth stage of 9-17 years （168 cm year-l）, and the highest increasing velocity of QWD （-181 mm year-1） was also observed at this stage. The thickness of DSL was significantly correlated with growth age and root depth of apple trees （r 〉 0.88）, whereas the QWD and mean SWC in DSLs were found to have no correlation with them. The optimal age of apple orchards for avoiding/controlling the formation of DSLs was about 9 years. This information provided pertinent references for the management of deep water resources by controlling the growth age of plants. key Words： deep soil, growth age, plant roots, soil desiccation, soil water content, soil-plant water relation.

关键词： deep soil growth age plant roots soil desiccation soil water content soil-plant water relation

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