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Crop production changes and the impact of Grain for Green program in the loess Plateau of China

Journal of Arid land 2020年第1期12卷 18-28页

作者： lYU Changhe XU Zhiyuan Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Institute of Rural Development Zhejiang Academy of Agricultural SciencesHangzhou 310021China

Since the Grain for Green(GFG)program was implemented in 1999,most steeply sloping farmlands in the loess Plateau of China have been returned to forestland and *** understand its impact on the food production,this study analyzed the spatiotemporal changes of food crop production(FCP)in the plateau and quantified the contribution of sown area and yield changes to the total FCP during 1998–2014 using factor decomposition models,and then discussed the impact of GFG program on the FCP based on literature *** the implementation of GFG program,total sown area in the loess Plateau quickly deceased by 17.3%from 1998 to 2003,and then gradually restored to 1.03×107 hm2 in ***,it slightly decreased to 1.02×107 hm2(94.6%of the area in 1998)in *** contrast,total FCP generally showed an apparent growth trend,averagely increased by 1.71%per year in the whole plateau during 1998–*** increase was jointly contributed by the improved yield of individual crops,and the adjustment of cropping structure,i.e.,the expansion of high yield maize *** factor decomposition analysis results indicate that the sown area shrinkage only reduced the growth rate of total FCP by 0.29%per year during 1998–2014,although a significant impact was found for the early stage of 1999–*** results suggest that the implementation of GFG program would not induce an obvious risk of the food ***,it is suggested that the GFG program should be set as a long-term strategic policy,by not only supporting the conversion of slope farmlands,but also helping local farmers to seek sustainable ways of land use to improve the income and *** can be combined with the poverty eradication program,to simultaneously achieve the national goals of ecological civilization building and the livelihood improvement of rural people in the loess *** rainfall limitation,the conversion of slope farmlands should be prioritized to grasslands.

关键词： spatiotemporal change farmland conversion hilly region factor decomposition semi-arid regions

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Response of Radial Growth of Pinus Tabulaeformis to Climate Along Precipitation Gradients in the Monsoon Marginal Zone

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SSRN 2024年

作者： Chen, Guoqing Zhang, Fen Wang, Yan liu, Wenhuo Gou, Xiaohua Key Laboratory of Western China's Environmental Systems of the Ministry of Education College of Earth and Environmental Sciences Lanzhou University Lanzhou730000 China Gansu Liancheng Forest Ecosystem Field Observation and Research Station Lanzhou University Lanzhou730000 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou730000 China

Climate change exerts a substantial impact on forest ecosystems, albeit the specific consequences vary across different locations and time periods. The monsoon marginal zone, an ecologically sensitive area, is particularly susceptible to the effects of climate change. Unfortunately, there exists a dearth of comprehensive studies examining the response of tree rings to climate change on a large scale within this region. This knowledge gap hinders our ability to effectively manage forest ecosystems and evaluate their capacity to sequester carbon in the face of climate change. To address this research gap and explore how tree growth responds to climate change in these areas, our study focused on nine sample sites of Pinus tabulaeformis (P. tabulaeformis) in the monsoon marginal zones characterized by uneven precipitation. Our findings revealed that drought emerges as the primary factor limiting tree growth in the monsoon marginal zone. However, variations in temperature and precipitation contribute to regional disparities in the patterns of tree ring-climate responses. Furthermore, we had observed that the tree ring-climate response pattern was gradually evolving due to climate warming. This change underscored the significant influence of climate drivers on tree growth within a single year. According to our results, tree growth within the target regions will suffer a notable decline while climate warmer and warmer. Additionally, extreme drought events possessed the potential to disrupt the stability of tree ring-climate response patterns, and the ecological resilience of trees to extreme events varies across different regions. Our findings provide important references for forest management under global climate change © 2024, The Authors. All rights reserved.

关键词： Climate change

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Inter-provincial Differences in Rice Multi-cropping Changes in Main Double-cropping Rice Area in China: Evidence from Provinces and Households

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Chinese Geographical Science 2019年第1期29卷 127-138页

作者： WANG Renjing lI Xiubin TAN Minghong XIN liangjie WANG Xue WANG Yahui JIANG Min Key laboratory of Land Surface Pattern and Simulation Institution of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences

Since the early 1980 s, the multi-cropping index for rice has decreased significantly in main double-cropping rice area in China, which is the primary double-cropping rice(DCR) production area. This decline may bring challenges to food security in China because rice is the staple food for more than 60% of the Chinese population. It has been generally recognized that rapidly rising labor costs due to economic growth and urbanization in China is the key driving force of the ‘double-to-single' rice cropping system adaption. However, not all provinces have shown a dramatic decline in DCR area, and labor costs alone cannot explain this difference. To elucidate the reasons for these inter-provincial distinctions and the dynamics of rice cropping system adaption, we evaluated the influencing factors using provincial panel data from 1980 to 2015. We also used household survey data for empirical analysis to explore the mechanisms driving differences in rice multi-cropping changes. Our results indicated that the eight provinces in the study can be divided into three spatial groups based on the extent of DCR area decline, the rapidly-declining marginal, core, and stable zones. Increasing labor cost due to rapid urbanization was the key driving force of rice cropping system adaption, but the land use dynamic vary hugely among different provinces. These differences between zones were due to the interaction between labor price and accumulated temperature conditions. Therefore, increasing labor costs had the greatest impact in Zhejiang, Anhui, and Hubei, where the accumulated temperature is relatively low and rice multi-cropping index declined dramaticly. However, labor costs had little impact in Guangdong and Guangxi. Differences in accumulated temperature conditions resulted in spatially different labor demands and pressure on households during the busy season. As a result, there have been different profits and rice multi-cropping changes between provinces and zones. Because of

关键词： multi-cropping change inter-provincial differences cropping system adaption accumulated temperature double-cropping rice area China

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Investigating the Effects of Greenhouse Vegetable Cultivation on Soil Fertility in lhasa, Tibetan Plateau

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Chinese Geographical Science 2020年第3期30卷 456-465页

作者： WANG Zhaofeng GONG Dianqing ZHANG Yili Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing100049China Chinese Acad-emy of Sciences Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China

The area of land utilized for growing vegetables in greenhouses has expanded rapidly on the Tibetan Plateau over recent decades. However, the effects of greenhouses on soil fertility as well as variations in these effects between the plateau and plain remain unclear on the Tibetan Plateau. This study assessed the effects of vegetable greenhouses in the vicinity of lhasa, using open field soil as a control. A total of 92 plough layer(0-20 cm depth) soil samples including 54 from greenhouses and 38 from open fields were taken, and soil pH, electrical conductivity(EC), total soluble salt(TS), soil organic matter(SOM), total nitrogen(TN), available phosphorus(AP), and available potassium(AK) were measured. The results reveal that, soil pH was lower 1.0 units in greenhouses than that in open field. TS was higher 82% and AP was higher 160% overall. Similarly, SOM and TN were higher 32% and 46%, respectively, while AK changed slightly at a higher 1% rate. Results also show that soil properties varied depending on cultivation time and vegetable types. Overall, pH continuously decreased with cultivation time while other soil fertility indicators reached a maximum value after nine years of cultivation before starting to decrease. The effect of leafy vegetable planting on soil was slight overall, while the impact of fruits on soil was more serious. Compared with changes in plain greenhouse soil fertility measured across the eastern China, the effects of greenhouses on soil in lhasa remain relatively limited;and the change in the degree of soil fertility was lower and the extreme values of soil fertility occurred later in lhasa.

关键词： facility agriculture soil nutrient imbalance soil environment lhasa Tibetan Plateau

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Flow Constrictions and Fish Behavior: Unraveling Undulatory Swimming Strategies in Accelerating Flow

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SSRN 2023年

作者： Xi, Yuqian li, Wenwi Zhang, Chendi liu, Shikang Cao, Chenyang li, Pengcheng Yang, Yacun Zheng, Hao Yao, Weiwei State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University Chengdu China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Department of Civil and Environmental Engineering University of Alberta EdmontonABT6G 1H9 Canada State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University No. 24 South Section 1 Yihuan Road Chengdu610065 China

Section contractions often induce accelerated flows in nature, exerting substantial influence on the swimming behaviors of various fish species. This study focus on the fish undulatory swimming strategies and effects of hydrodynamics on the swimming behavior in a flume with constriction. Through using a combination of computational fluid dynamics (CFD) modeling, convolutional neural network (CNN) and observation of fish behavior with kinematic and morpho-kinematic, we investigate how fish select their swimming strategies when encountering complex flow conditions. The results reveal that fish exhibit distinct swimming behaviors in response to accelerating flows, including avoidance behavior, drifting with the flow, and escaping upstream. Besides, fish demonstrate a preference for swimming on one side of the flume, with the side bank of the adaptation region being the most favored location due to lower flow velocity and thigmotactic behavior. Additionally, we identify three swimming gaits employed by the fish to navigate complex river environments, adjusting their swimming behavior based on environmental cues. This study highlights the significance of both head and tail characteristics in governing fish swimming behavior, with head features crucial for perceiving the environment and tail movements directly influencing swimming speed and maneuverability. The findings have valuable implications for fisheries conservation and management, guiding the design of fish passage devices and exclusion barriers for safe migration through regulated river systems, and also contributing valuable insights to the development of fish-inspired robotic systems. © 2023, The Authors. All rights reserved.

关键词： Hydrodynamics

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Metal oxide modified biochars for fertile soil management: Effects on soil phosphorus transformation, enzyme activity, microbe community, and plant growth

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Environmental Research 2023年第Part3期231卷 116258页

作者： Peng, Yutao Chen, Qing Guan, Chung-Yu Yang, Xiao Jiang, Xiaoqian Wei, Mi Tan, Jinfang li, Xiaoyun School of Agriculture Sun Yat-sen University Guangdong Guangzhou518107 China Modern Agricultural Innovation Center Henan Institute of Sun Yat-sen University China Beijing Key Laboratory of Farmyard Soil Pollution Prevention Control and Remediation College of Resources and Environmental Sciences China Agricultural University Beijing100193 China Department of Environmental Engineering National Ilan University Yilan260 Taiwan Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China

Metal oxide modified biochars are increasingly being used for intensive agricultural soil remediation, but there has been limited research on their effects on soil phosphorus transformation, soil enzyme activity, microbe community and plant growth. Two highly-performance metal oxides biochars (FeAl-biochar and MgAl-biochar) were investigated for their effects on soil phosphorus availability, fractions, enzyme activity, microbe community and plant growth in two typical intensive fertile agricultural soils. Adding raw biochar to acidic soil increased NH4Cl–P content, while metal oxide biochar reduced NH4Cl–P content by binding to phosphorus. Original biochar slightly reduced Al–P content in lateritic red soil, while metal oxide biochar increased it. lBC and FBC significantly reduced Ca2–P and Ca8–P properties while improving Al–P and Fe–P, respectively. Inorganic phosphorus-solubilizing bacteria increased in abundance with biochar amendment in both soil types, and biochar addition affected soil pH and phosphorus fractions, leading to changes in bacterial growth and community structure. Biochar's microporous structure allowed it to adsorb phosphorus and aluminum ions, making them more available for plants and reducing leaching. In calcareous soils, biochar additions may dominantly increase the Ca (hydro)oxides bounded P or soluble P instead of Fe–P or Al–P through biotic pathways, favoring plant growth. The recommendations for using metal oxides biochar for fertile soil management include using lBC biochar for optimal performance in both P leaching reduction and plant growth promotion, with the mechanisms differing depending on soil type. This research highlights the potential of metal oxide modified biochars for improving soil fertility and reducing phosphorus leaching, with specific recommendations for their use in different soil types. © 2023 Elsevier Inc.

关键词： Enzyme activity

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Temperature variations evidenced by records on the latest spring snowing dates in Hangzhou of eastern China during 1131–1270AD

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Journal of Geographical Sciences 2020年第10期30卷 1664-1680页

作者： lIU Haolong DAI Junhu YAN Junhui HE Fanneng GE Quansheng MU Chongxing Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China The College of Urban and Environmental Sciences Xinyang Normal UniversityXinyang 464000HenanChina The Taizhou Meteorological Bureau Taizhou 318000ZhejiangChina

We collected and verified documentary records of the latest spring snowing dates(lSSD)in Hangzhou during Southern Song ***,the statistical correlation between this proxy and February–April mean temperature in Hangzhou was examined,and samples later than the perennial mean of the lSSD during Southern Song Dynasty were transformed into the decadal mean of lSSD by means of Boltzmann *** characteristics of this reconstructed lSSD series with a 10-year temporal resolution was analyzed,and it was also compared with other documentary evidences and reconstructed climate series in China for the period 1131–*** results and discussion suggested that:(1)Records of the lSSD in Hangzhou during Southern Song Dynasty did not refer to ice pellets and graupels,which had an explicit climate significance(–0.34℃/10 d,R2=0.37,p<0.001).However,when this proxy is used to reconstruct temperature changes,all dates should be converted into proleptic Gregorian style and meet the same criterion of"true Qi"as the Chinese traditional calendar after 1929.(2)The decadal mean of lSSD can be effectively estimated by using the forefront of lSSD in the decade on the basis of Boltzmann function,whose extrapolation has a lesser uncertainty than those on the basis of linear models or polynomial models.(3)The spring climate in Hangzhou during 1131–1270 was almost as warm as the period 1951–*** the centennial scale,this period can be divided into two phases:the cold 1131–1170 and the warm 1171–*** the latter,1181–1200 and 1221–1240 were two cold intervals at the multi-decadal scale.(4)The reconstructed lSSD series was consistent well with other documentary evidences and reconstructed climate series in China for 1131–1270,which may reflect the influence on the climate over most regions of China imposed by the Pacific Decadal Oscillation(PDO).

关键词： Southern Song Dynasty Hangzhou the latest spring snowing dates climatic significance general characteristics of temperature variation

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An Innovative Approach to Evaluate Debris Flow Scale-Activity Across Diverse Aridity Zones: Fusion of Image Recognition and Geomorphometric Analysis

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SSRN 2024年

作者： Jiang, Zhenni Wang, Jiao Zhang, Guotao Cui, Peng Yang, Can Zhang, Yifan Zhang, Bo li, Chaoyue Wang, Hao liu, Jie Yang, Zhiwei Chengdu610041 China University of Chinese Academy of Sciences Beijing100049 China China-Pakistan Joint Research Center on Earth Sciences CAS-HEC Islamabad45320 Pakistan Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China Xinjiang Transportation Planning Survey and Design Institute Co. Ltd. Urumqi830006 China Key Laboratory of Highway Engineering Technology in Arid and Desert Region of Ministry of Transport Urumqi83001l China

Debris flows, which can be savage in mountainous regions, have been increasingly rampant in arid areas, threatening nearby residents and properties. Inadequate high-quality data, labor-intensive image interpretation, inefficient field surveys, and traditional singular-variable analyses underscore the necessity for an integrative and efficient approach to evaluate debris flow scales and activities. Thus, an integrative debris flow scale-activity assessment methodology is developed, composed of parameters commonly studied and those feasible for extraction from accessible sources, leveraging dynamic avulsion of fans with distinct morphometry and boulder visibility in images. Resultantly, channel number, fan size, maximum critical shear stress, and disaster frequency are acquired as potential index parameters via geomorphometric analysis and image segmentation. The composite index generation, established based on these parameters and principal component analysis, is highly effective and accurate, benefiting from program efficiency, interpretation-based error control, parameter validation, and data preservation. Comprehensively, three types of disasters were identified in the study region, distinguished by water content and sediment composition. Parameter and index results reveal considerable spatial-temporal disparities, complex relationships, and clustering patterns (Moran’s I=0.08) across disaster and aridity types owing to environmental variances. The index (degree) exhibits an increasing-decreasing transition from low-index hyper-concentrated flows to high-index debris floods and debris flows and declines to less impactful debris floods as aridity decreases due to different sediment and water discharge and source. Generally, high indices tend to concentrate in the southern and glacierized northern valleys, exhibiting medium impact ranges, high maximum critical shear stress, and dynamic channel activities regarding channel quantities and disaster frequencies. Hence,

关键词： Shear stress

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A Spatial Analysis of Urban Color Harmony in Five Global Metropolises

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Journal of Resources and Ecology 2022年第2期13卷 238-246页

作者： CHEN Naige XU Xiaofan TAN Minghong WANG Xianming Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China International College University of Chinese Academy of SciencesBeijing 100049China Natural Resources and Planning Bureau of Heze Shandong 274000China

Harmonious urban color can reduce urban light pollution,relieve the urban heat island effect,improve the living quality and form a distinctive ***,due to the manifold architectural styles,urban color in metropolises typically becomes complicated,which may destroy the color harmony of *** to now,there has not been enough research on the quantitative expression of the degree of color harmony,and the research on comparing the urban color characteristics of different metropolises is also relatively *** paper firstly developed a method to quantitatively measure the degrees of color harmony(DCHs)of five metropolises in 2020:london,Tokyo,Chicago,Paris,and Beijing,by writing a Python program and using the Sentinel-2 A remote sensing *** buffers were then used to analyze the spatial distribution of the DCHs within each *** addition,20 typical samples were selected to analyze the differences of the DCHs between residential and industrial *** results showed that:(1)The values of the DCHs of london and Tokyo were the highest,followed by Chicago and Paris,while Beijing was the lowest.(2)The values of the DCHs were increasing from the inside out in Chicago,Paris,and london,while those in Beijing and Tokyo were decreasing.(3)The values of the DCHs in industrial areas were much lower than in residential *** on the above results,policy implications are provided for color management of these ***,this study may provide a method for the rapid analysis the DCHs for other metropolises.

关键词： spatial analysis urban color harmony global metropolis cityscape

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Natural Factors Play a Dominant Role in the Short-Distance Transmission of Pine Wilt Disease

SSRN

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SSRN 2022年

作者： liu, Yanqing Huang, Jixia Wu, Jin Zong, Shixiang Precision Forestry Key Laboratory of Beijing Beijing Forestry University Beijing100083 China Key Laboratory of Land Surface Pattern and Simulation Chinese Academy of Sciences Beijing100101 China Research Area of Ecology and Biodiversity School for Biological Sciences The University of Hong Kong Hong Kong State Key Laboratory of Agrobiotechnology The Chinese University of Hong Kong Shatin Hong Kong The Chinese University of Hong Kong Hong Kong

Pine wilt disease (PWD) is regarded as one of the most serious conifer diseases affecting pines worldwide. Past research on the spread of pine wilt nematodes (PWNs, Bursaphelenchus xylophilus) can provide the theoretical basis for the prevention and control of PWD in forests and reduce the ecological and economic losses caused by PWD. To date, an in-depth study of the driving mechanisms behind short-distance PWD spread is lacking. In this study, we collected PWD forest subcompartment data in Fushun, China, and analysed the roles of natural and human factors on the short-distance transmission of PWD;the analysed factors included the number of neighbouring PWD-infected forest subcompartments, the canopy density, the slope aspect and different traffic corridor levels. The results suggested that natural factors dominated the short-distance transmission of PWD, contributing 84% of the observed spread, while human factors contributed 16%. Among the analysed natural factors, the spatial spill-over effect of nearby PWD-infected subcompartments contributed the most to short-distance PWD transmission. With the help of a beetle medium, PWD can spread to nearby forest subcompartments, and this spatial PWD spill-over effect showed a linearly decaying trend as the distance to neighbouring subcompartments increased. Different traffic corridor levels exhibited significant PWD transmission force differences. County roadways and highways had great impacts, while other traffic corridors had relatively small impacts. For each additional 1 km of distance from a county roadway, highway, national or provincial roadway, the PWD infection risks in forest subcompartments were reduced by 16%, 12%, 5% and 3%, respectively. In this study, we quantified the influence of natural and human factors on the short-distance spread of PWD and provided a theoretical basis for the control of PWD transmission;the results obtained herein are critical for maintaining the ecological security of forests, promo

关键词： Human engineering

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