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Ecological effect of the plantation of Sabina vulgaris in the Mu Us Sandy Land,China

Journal of Arid Land 2024年第1期16卷 14-28页

作者： NAN Weige DONG Zhibao zhou zhengchao LI Qiang CHEN Guoxiang School of Geography and Tourism Shaanxi Normal UniversityXi'an 710062China Shaanxi Key Laboratory of Ecological Restoration in Shaanbei Mining Area Yulin UniversityYulin 719000China College of Prataculture Gansu Agricultural UniversityLanzhou 730070China

Vegetation restoration through artificial plantation is an effective method to combat desertification,especially in arid and semi-arid *** study aimed to explore the ecological effect of the plantation of Sabina vulgaris on soil physical and chemical properties on the southeastern fringe of the Mu Us Sandy Land,*** collected soil samples from five depth layers(0-20,20-40,40-60,60-80,and 80-100 cm)in the *** plantation plots across four plantation ages(4,7,10,and 16 years)in November 2019,and assessed soil physical(soil bulk density,soil porosity,and soil particle size)and chemical(soil organic carbon(SOC),total nitrogen(TN),available nitrogen(AN),available phosphorus(AP),available potassium(AK),cation-exchange capacity(CEC),salinity,p H,and C/N ratio)*** results indicated that the soil predominantly consisted of sand particles(94.27%-99.67%),with the remainder being silt and *** plantation age increased,silt and very fine sand contents progressively *** 16 years of planting,there was a marked reduction in the mean soil particle *** initial soil fertility was low and declined from 4 to 10 years of planting before witnessing an *** positive correlations were observed for the clay,silt,and very fine sand(mean diameter of 0.000-0.100 mm)with SOC,AK,and p *** contrast,fine sand and medium sand(mean diameter of 0.100-0.500 mm)showed significant negative correlations with these *** findings ascertain that the plantation of *** requires 10 years to effectively act as a windbreak and contribute to sand fixation,and needs 16 years to improve soil physical and chemical ***,these improvements were found to be highly beneficial for vegetation restoration in arid and semi-arid *** research can offer valuable insights for the protection and restoration of the vegetation ecosystem in the sandy lands in China.

关键词： Sabina vulgaris plantation age soil physical and chemical properties soil particle size soil fertility vegetation restoration Mu Us Sandy Land

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钚同位素示踪技术在树木年轮中的应用研究进展

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地理科学 2024年第5期44卷 911-916页

作者：曹立国周正朝常晓娇曾小敏王宁陕西师范大学地理科学与旅游学院陕西西安710119 大连市现代农业生产发展服务中心辽宁大连116000

钚(Pu)核素具有极强的辐射毒性和生物毒性,对动植物和人类健康危害巨大,分析Pu同位素在树轮中的水平、迁移规律及其污染历史对于潜在的生态安全和植物毒性评价至关重要。在中国核电事业快速发展的背景下,建立不同区域树轮的Pu同位素背... 详细信息

钚(Pu)核素具有极强的辐射毒性和生物毒性,对动植物和人类健康危害巨大,分析Pu同位素在树轮中的水平、迁移规律及其污染历史对于潜在的生态安全和植物毒性评价至关重要。在中国核电事业快速发展的背景下,建立不同区域树轮的Pu同位素背景数据尤为迫切。为此,本文对目前现存的少量文献资料进行了总结和归纳,首先简要阐述了环境中Pu同位素来源与沉降模式;重点分析了Pu同位素进入树轮的潜在途径,以及Pu同位素在树轮中的径向分布特征及其指示意义;最后,本文强调了建立树轮Pu同位素化学分析测试方法的重要性,及其示踪应用的发展方向,对于促进和拓展树轮Pu同位素示踪研究具有重要现实意义。

关键词： ^(239+240)Pu ^(137)Cs 树木年轮核素示踪

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Changes in soil organic carbon and nitrogen after 26 years of farmland management on the Loess Plateau of China

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Journal of Arid Land 2015年第6期7卷 806-813页

作者： zhou zhengchao ZHANG Xiaoyan GAN Zhuoting Department of Tourism and Environmental Sciences Shaanxi Normal University Key Laboratory of Disaster Survey and Mechanism Simulation of Shaanxi Province Baoji University of Arts and Sciences

Soil carbon（C） and nitrogen（N） play a crucial role in determining the soil and environmental quality. In this study, we investigated the effects of 26 years（from 1984 to 2010） of farmland management on soil organic carbon（SOC） and soil N in abandoned, wheat（Triticum aestivum L.） non-fertilized, wheat fertilized（mineral fertilizer and organic manure） and alfalfa（Medicago Sativa L.） non-fertilized treatments in a semi-arid region of the Loess Plateau, China. Our results showed that SOC and soil total N contents in the 0–20 cm soil layer increased by 4.29（24.4%） and 1.39 Mg/hm2（100%）, respectively, after the conversion of farmland to alfalfa land. Compared to the wheat non-fertilized treatment, SOC and soil total N contents in the 0–20 cm soil layer increased by 4.64（26.4%） and 1.18 Mg/hm2（85.5%）, respectively, in the wheat fertilized treatment. In addition, we found that the extents of changes in SOC, soil total N and mineral N depended on soil depth were greater in the upper soil layer（0–30 cm） than in the deeper soil layer（30–100 cm） in the alfalfa land or fertilizer-applied wheat land. Fertilizer applied to winter wheat could increase the accumulation rates of SOC and soil total N. SOC concentration had a significant positive correlation with soil total N concentration. Therefore, this study suggested that farmland management, e.g. the conversion of farmland to alfalfa forage land and fertilizer application, could promote the sequestrations of C and N in soils in semi-arid regions.

关键词： soil organic carbon(SOC) soil N fertilizer land use change semi-arid area

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Different Responses of Vegetation to Frozen Ground Degradation in the Source Region of the Yellow River from 1980 to 2018

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Chinese Geographical Science 2020年第4期30卷 557-571页

作者： WANG Rui DONG Zhibao zhou zhengchao School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China

Frozen ground degradation under a warming climate profoundly influences the growth of alpine vegetation in the source region of the Qinghai-Tibet *** study investigated spatiotemporal variations in the frozen ground distribution,the active layer thickness(ALT)of permafrost(PF)soil and the soil freeze depth(SFD)in seasonally frozen soil from 1980 to 2018 using the temperature at the top of permafrost(TTOP)model and Stefan *** compared the effects of these variations on vegetation growth among different frozen ground types and vegetation types in the source region of the Yellow River(SRYR).The results showed that approximately half of the PF area(20.37%of the SRYR)was projected to degrade into seasonally frozen ground(SFG)during the past four decades;furthermore,the areal average ALT increased by 3.47 cm/yr,and the areal average SFD decreased by 0.93 cm/yr from 1980 to ***,the growing season Normalized Difference Vegetation Index(NDVI)presented an increasing trend of 0.002/10 yr,and the increase rate and proportion of areas with NDVI increase were largest in the transition zone where PF degraded to SFG(the PF to SFG zone).A correlation analysis indicated that variations in ALT and SFD in the SRYR were significantly correlated with increases of NDVI in the growing ***,a rapid decrease in SFD(<-1.4 cm/10 yr)could have reduced the soil moisture and,thus,decreased the *** NDVI for most vegetation types exhibited a significant positive correlation with ALT and a negative correlation with ***,the steppe NDVI exhibited a significant negative correlation with the SFD in the PF to SFG zone but a positive correlation in the SFG zone,which was mainly limited by water condition because of different change rates of the SFD.

关键词： permafrost seasonally frozen ground vegetation dynamics climate change source region of the Yellow River

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Quantitative assessment of the spatial distribution of^(239+240)Pu inventory derived from global fallout in soils from Asia and Europe

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Journal of Geographical Sciences 2022年第4期32卷 605-616页

作者： CAO Liguo zhou zhengchao WANG Ning XIAO Shun School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China

Due to the atmospheric nuclear weapon tests carried out,terrestrial environments have been extensively contaminated by global fallout of plutonium(Pu)***^(239+240)Pu inventories in soil profiles from undisturbed and flat forest or grasslands(reference sites)mainly from Europe and Asia are considered as important background for evaluating soil ***,we conducted a literature survey over an area extending from 2.6°W to 148.9°E and from 53.2°S to 76.6°N,with the purpose of analyzing the spatial distribution of^(239+240)Pu inventories and possible controlling *** aim of this work was to derive an empirical model of^(239+240)Pu inventory based on currently available^(239+240)Pu data,precipitation and *** results show that,in general,the latitudinal distribution of^(239+240)Pu inventory was consistent with the UNSCEAR ***,the^(239+240)Pu inventories are higher than the UNSCEAR data,especially in the Northern *** addition,close relationships(at the 0.01 significance level)were identified between^(239+240)Pu inventories and annual precipitation and *** empirical formula was therefore developed to estimate^(239+240)Pu inventories in soils based on latitude and precipitation ***,future research may require more data of measured^(239+240)Pu inventories in soil profiles that can be used to compare,validate and improve upon the accuracy of the inferred empirical equation.

关键词： spatial distribution plutonium global fallout precipitation

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Risk Assessment of Heavy Metal Pollution in Sediments of the Fenghe River by the Fuzzy Synthetic Evaluation Model and Multivariate Statistical Methods

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Pedosphere 2016年第3期26卷 326-334页

作者： YANG Yang zhou zhengchao BAI Yanying CAI Yimin CHEN Weiping State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences College of Environment and Tourism Shaanxi Normal University Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences

Concentrations of heavy metals in 74 sediment samples from the Fenghe River, which originates from the north of the Qinling Mountains and flows through Xi'an, Shaanxi Province, China, were characterized by employing geographic information system(GIS)mapping, fuzzy synthetic assessment, and multivariate statistical analysis to determine the enrichment characteristics of heavy metals as well as their potential risks of pollution to sediments. Al, Cd, and Co were the major pollutants, with a high enrichment factor(EF) value. Heavy metal concentrations from samples near the paper plant were maintained at a high level. Significant enrichment of Al, Ba, Cr, Ni, Pb, and Co was found in the midstream and downstream, while high concentration of Cu occurred in the headwater stream. Based on the cluster and principal component analyses, sediment metals mainly came from the paper plants, agronomic practices, natural sources, and tourism, with a contribution of 51.59%, 23.01%, 14.21%, and 9.88%, respectively. Sediment pollution assessment explored using fuzzy theory based on the entropy method and toxicity coefficient showed that 26, 32, and 11 sites fell into Class III(slightly polluted), Class IV(moderately polluted), and Class V(heavily polluted), respectively, and their scores of membership degree in the polluted level were on the rise, suggesting a relatively high degree of sediment metal pollution in the study area. Closely related to the excessive industrial and agricultural applications, metal pollution in sediment is necessary to be addressed in the Fenghe River.

关键词： fuzzy theory risk analysis river ecosystem sediment pollution spatial analysis

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Changes in the soil microbial communities of different soil aggregations after vegetation restoration in a semiarid grassland,China

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Soil Ecology Letters 2021年第1期3卷 6-21页

作者： Zhijing Xue zhengchao zhou Shaoshan An School of Geography and Tourism Shaanxi Normal UniversityXi’an 710119China State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau Northwest A&F UniversityYangling 712100China

Soil aggregate fractions can regulate microbial community composition and structure after vegetation ***,there has been less focus on the effects of soil aggregate fractions on the distributions of microbial ***,we used phospholipid fatty acid(PLFA)analysis to explore the effects of different years of vegetation restoration(a 35-year-old Thymus mongolicus community(Re-35yrs)and a 2-year-old nongrazing grassland(Ug-2yrs))on microbial communities within different soil aggregate sizes(5 mm).The results indicated that the amount of total PLFA in Re-35yrs was 10 times greater than that in *** soil aggregate stability increased with increasing duration of vegetation *** Re-35yrs,the total PLFA shown an increase as the soil aggregate size increased,and the highest values were observed in 3–5 ***-2yrs differed from Re-35yrs,the soil microbial diversity was higher in medium particle sizes(1–2 mm and 2–3 mm)and lower in microaggregates(5 mm).Soil microbial diversity was highest in large particle size aggregates,which resulted in low environmental stress and strong *** same tendency was observed in the high values of cyc/prec,S/M and soil organic matter,which indicated a lower turnover speed(F/B)of fungal energy utilization and a higher fixation *** years of natural restoration,the soil microbial community generally transformed from nutrient-rich to heterotrophdominant,especially in microaggregates(reflected in the G^(+)/G^(–)ratio).

关键词： Vegetation restoration Plant succession Phospholipid fatty acid(PLFA) Soil aggregate fractions Soil microorganism group

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Characteristics and Cause Analysis of Variations in Light Precipitation Events in the Central and Eastern Tibetan Plateau,China,During 1961–2019

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Chinese Geographical Science 2022年第1期32卷 155-173页

作者： LI Kaifang CAO Liguo zhou zhengchao JIAO Lei WANG Ning LIU Ruohan School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China School of Urban and Rural Planning and Architectural Engineering Shangluo UniversityShangluo 726000China

The Tibetan Plateau(TP)is one of the most sensitive areas and is more susceptible to climate change than other regions in *** TP also experiences extremely frequent light precipitation events compared to precipitation of other ***,the definition,influencing factors,and characteristics of light precipitation in the TP have not been accurately *** study investigated the variation characteristics of light precipitation with intensities(Pre)of 0.1-10.0 mm/d based on climate data from 53 meteorological stations over the central and eastern TP from 1961 to *** detailed analysis,light precipitation events were classified into five grades:G1[0.1-2.0 mm/d),G2[2.0-4.0 mm/d),G3[4.0-6.0 mm/d),G4[6.0-8.0 mm/d),and G5[8.0-10.0 mm/d).The results showed that both the amount of precipitation and number of precipitation days had increased significantly at rates of 4.0-6.0 mm/10 yr and 2.0-4.0 d/10 yr,respectively,and most precipitation events were of low intensity(0.1≤Pre<2.0 mm/d).Light precipitation events mainly occurred in the southeast of the study area,and it showed an increasing trend from the northwest to the *** changes in light precipitation primarily occurred in the 1980 s.A comprehensive time series analysis using the Mann-Kendall test and Morlet wavelet was performed to characterize the abrupt changes and cycles of light *** the study period,the main periods of light precipitation corresponded to the 6 yr cycle,with obvious periodic oscillation characteristics,and this cycle coexisted with cycles of other *** correlations were observed between the amount of light precipitation and temperature over the study *** findings will enhance our understanding of changes in light precipitation in the TP and provide Scientific basis for the definition of light precipitation in the future.

关键词： light precipitation events spatio-temporal variation period analysis Tibetan Plateau

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Preliminary Design of a Flat-Staircase Intelligent Wheelchair

Preliminary Design of a Flat-Staircase Intelligent Wheelchai...

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2015年中国智能自动化学术会议

作者： zhengchao zhou Juanxiu Liu Yifei Wu College of Automation Nanjing University of Science and Technology

The traditional manual wheelchairs and even electric wheelchairs do not have the function of climbing stairs, which limits freedom of the users. A flatstaircase intelligent wheelchair is presented in this article to improve the quality of the users’ life, making them have more space and freedom. The article firstly introduces the mechanical structure of the intelligent wheelchair and elaborate the stair-climbing and flat-moving principle. Then according to the concept of modularization design, this article respectively puts forward the driving and controlling scheme of stair-climbing module and flat-moving module. Afterwards, the main controller hardware circuit based on TMS320F28335, operating lever hardware circuit and the driving hardware circuit of stair-climbing motor and flat-moving motor are given respectively. Next, the system software modules of the wheelchair is put forward and underlying driving program is written to realize motor control of brushless commutation and closed-loop speed control based on Partition PI algorithm. Then the joint debugging of the intelligent wheelchair is carried on and the test data figure is provided. Finally, the article summarizes the project and puts forward the prospects for future work.

关键词： Intelligent wheelchair Climbing stairs BLDC DSP IPM

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红豆草与土壤氮含量对大气二氧化碳浓度升高的响应

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应用生态学报 2006年第11期17卷 2175-2178页

作者：周正朝上官周平中国科学院水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室杨凌712100

在封闭的植物培养箱中，通过盆栽实验，研究了红豆草和土壤氮含量对CO2浓度增加的响应、结果表明，与正常CO2浓度（355—370μmol·mol^-1）相比，CO2浓度升高（700μmol·mol^-1），植物生物量增加25．1％（P〈0．01）．但植物体氮浓... 详细信息

在封闭的植物培养箱中，通过盆栽实验，研究了红豆草和土壤氮含量对CO2浓度增加的响应、结果表明，与正常CO2浓度（355—370μmol·mol^-1）相比，CO2浓度升高（700μmol·mol^-1），植物生物量增加25．1％（P〈0．01）．但植物体氮浓度降低25．3％（P〈0．001），植物全氮没有显著的变化．经3个月盆栽实验后，与原始土壤相比，两种CO2浓度处理土壤全N、NO3^--N和NH4^＋-N都有所降，而土壤微生物氮则显著增加，这可能与植物生长有关．不同CO：浓度处理土壤NH4^＋-N浓度基本一致，但在高CO2浓度下．土壤NO3^--N浓度显著降低，而微生物生物氮显著增加．对整个土壤，植物系统而占，盆栽实验后，整个系统全氮有少量增加，但变化不显著，特别是在高CO2浓度条件下，土壤-植物系统全氮最大，这可能与培养材料红最草为豆科植物，而且在高CO2浓度下生物量增加，导致氮的固定量增加有关．

关键词： CO2升高土壤N 微生物生物N 植物N 红豆草

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