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The cultivation industry occupies a large proportion of greenhouse gas emissions in agriculture. Assessing greenhouse gas emissions from the cultivation industry is pivotal for mitigating emissions and promoting sustainable cultivation. Utilizing greenhouse gas emission calculation methods recommended by the Intergovernmental Panel on Climate Change (IPCC) and other methods, this work evaluated annual emissions and the emission structure of major crops from 2005 to 2021 in the Chengdu Plain, a significant agricultural region in Southwest China. We identified nitrogen fertilizer as the primary contributing factor to high emissions from cultivation production. Subsequently, we analyzed the trend and utilization of nitrogen fertilizer, which proposes essential strategies for reducing greenhouse gas emissions. The results showed that greenhouse gas (GHG) emissions from the cultivation industry in the Chengdu Plain exhibited a growth, fluctuation, and eventual decline trend from 2005 to 2021. The emissions increased from 5,148,900 t in 2005 to 6,289,700 t in 2009, representing a 22.16% increase, and subsequently decreased to 5,109,900 t in 2021, marking a 23.31% decrease. Nitrogen fertilizer application emerges as the primary source of GHG emissions, constituting approximately half of the total, with nitrogen fertilizer manufacturing contributing significantly as well, collectively amounting to about 70%. We also found that the proportion of greenhouse gas emissions attributed to cash crop cultivation has gradually increased over the last decade. Among these crops, vegetables exhibit the highest emissions, comprising nearly half of the total emissions from 2019 onwards. However, the nitrogen fertilizer use efficiency of cash crops is less than 30%, with higher nitrogen surplus, ammonia volatilization, and nitrogen leaching per unit area, and the total amount is higher than that of grain crops. Among cash crops, vegetables exhibit the highest amount of nitrogen surplus, ammonia volatilization, and nitrogen leaching, constituting nearly half of the total amount in the study area since 2019. Our findings significantly affect sustainable and low-carbon cultivation industry development in the study area. [ABSTRACT FROM AUTHOR]

Archaeological discoveries and historical documents show that the Chengdu Plain was the most important iron production center in the southwest region of China during the Qin and Han dynasties. However, due to the lack of archaeological evidence, the iron production technology of cities in the Chengdu Plain during the Qin and Han dynasties remains unclear. The Xindu city site is located in Qingbaijiang District, Chengdu Sichuan Province. It was an important city site in the Chengdu Plain during the Han and Jin dynasties. During excavation of the Xindu city site, archaeologists unearthed a large number of metallurgical remains such as slags and tuyeres, as well as two severely damaged hearth bases near the western city wall. Scientific analysis results suggest that the metallurgical remains are related to the steel fining process and could be dated back to the Western Han Dynasty. The metallurgical remains in the Xindu city are the earliest known artifacts associated with the steel fining process in southwest China. This discovery also marks the first identification of iron industry workshops in a Han Dynasty city in the Chengdu Plain. The findings reveal a different industrial layout pattern from previously discovered Han Dynasty metallurgical sites in the Chengdu Plain. Additionally, this discovery provides archaeometallurgical evidence for the central government's development in southwest China during the Han Dynasty. [ABSTRACT FROM AUTHOR]

As the economic center and major grain-producing area in Southwest China, the calculation of the carbon budget and the protection of cultivated land in the Chengdu Plain are of vital significance for China to achieve a carbon peak strategy and ensure food security. For the purpose of clarifying the trend of land use focus and carbon emissions in the Chengdu Plain, the carbon peak level of land use in 33 counties in the Chengdu Plain was explored. Based on the gravity center model and IPCC carbon emission coefficient method, the changing trend of land use gravity center and carbon emission in Chengdu Plain from 2006 to 2022 was clarified. PLS regression model and LMDI model were used to explore the main influencing factors of the carbon emission of cropland and the carbon emission of building land. PLUS model was used to simulate future land use patterns and carbon emissions. (1) The center of gravity of cropland, building land, water, and other and unused land shifted to the northeast by 4.23 km, 5.46 km, 8.44 km, and 31.58 km, respectively, and that of forest and grass shifted to the southeast by 11.12 km and 3.41 km, respectively. For major food crops, the centers of gravity of rice and maize moved northeastward by 15.47 km and 7.52 km, respectively, while wheat moved southwestward by 17.77 km. (2) From 2006 to 2022, carbon emissions from land use in the 33 counties of the Chengdu Plain are all on the rise, with a total increase of 13.552 million tons, and carbon sinks in the 31 counties continue to decline, with a total decrease of 0.691 million tons. (3) Under the natural scenario, carbon sink scenario, and carbon reduction scenario, the carbon emissions from land use decrease by 0.5391 million tons, 3.4728 million tons, and 4.5265 million tons from 2022, respectively. Among the 33 counties in the Chengdu Plain, 11 counties did not achieve carbon peak under the natural scenario, 5 counties did not achieve carbon peak under the carbon sink scenario, and all the counties achieved carbon peak under the carbon sink scenario. During the study period, there was a serious loss of cropland in the Chengdu Plain, mainly to building land in the central part of the Chengdu Plain and to forests within the Longmen Mountain, Longquan Mountain, and Leshan City, and there is a need to strengthen cropland protection in this region in the future. Under the natural scenario, carbon sink scenario, and carbon reduction scenario, land use in the Chengdu Plain region can achieve carbon peak, and the carbon reduction model will be more helpful for the counties to achieve carbon peak. [ABSTRACT FROM AUTHOR]

Cultivated land is the cornerstone of grain production and the basic resource to ensure food security. Understanding the non-grain production status of cultivated land in the main grain-producing areas of western China is necessary to provide a basis for regional sustainable agricultural development and cultivated land protection decision-making. In this study, Chengdu Plain was selected as an empirical research area. A mathematical quantization model and spatial autocorrelation method were used to analyze the spatiotemporal characteristics of non-grain production of cultivated land in Chengdu Plain, and an econometric model was constructed to identify its driving factors. The results showed that the cultivated land area did not change significantly in the Chengdu Plain from 2000 to 2019; however, the small change in cultivated land area did not mean that its actual use changed little, and the non-grain production status of cultivated land was obvious. (1) From 2000 to 2019, both the Non-Grain production Area (NGA) and the Non-Grain production Rate (NGR) in Chengdu Plain showed a fluctuating and increasing trend, with an increased rate of 4.40% and 13.53%, respectively, which indicates that cultivated land protection and food security were under great pressure. (2) In terms of space, the NGA in 34 districts and counties of Chengdu Plain presents a multi-center scattered distribution, which shows a spatial pattern of high in the center and low in the northeast and southwest, and the NGA's spatial agglomeration areas are concentrated in Chengdu and its neighboring cities. (3) Economic Crop Planting Scale (ECPS), Agricultural Structure Adjustment (ASA), Urbanization Rate (UR), and Cultivated Land Protection Policy (CLPP) are the most important factors affecting the non-grain transformation of cultivated land in Chengdu Plain. Some suggestions are proposed: red lines should be drawn to implement a control system for cultivated land use; departmental collaboration must be strengthened to build a synergy of cultivated land protection; the agricultural subsidy system must be improved to defend farmers' fundamental rights and interests; and policy advocacy for cultivated land protection should be enhanced to raise food security awareness. This study can better reflect the non-grain production status of cultivated land in Chengdu Plain, and from the spatial unit of district and county, it provides a good perspective for the study of the non-grain production of cultivated land. This study also provides a scientific foundation for decision-making regarding regional sustainable agricultural development and cultivated land protection.

The Chengdu Plain serves as the central hub for economic development in Sichuan Province. The study of its surface deformation plays a pivotal role in disaster prevention and ensuring the safety of lives and property. Based on SBAS-Interferometric Synthetic Aperture Radar technology, this paper derived the land surface deformation in the Chengdu Plain from January 2020 to October 2022, and analyzed it in relation to urban development and other natural environmental factors. Results are as follows: (1) The overall surface deformation in the study area remains stable, with a noticeable trend of westward uplift and eastward decline. Significant uplift is identified in Dujiangyan and Pengzhou, located near the Longmen Mountain, with a maximum uplift rate of +61 mm/year. Conversely, subsidence is evident from Qingbaijiang District in Chengdu to Deyang, with subsidence rates reaching a maximum of −87.8 mm/year. In the areas of Dayi and Qionglai, subsidence is relatively minor. The surface subsidence phenomenon in the study area is primarily associated with urban development. (2) The mean grey correlation coefficient between the time-series cumulative surface deformation and precipitation is 0.71, which suggests a strong relationship between the surface deformation and precipitation in the Chengdu Plain. However, a time delay is observed between the changes in surface deformation and precipitation. (3) The Longmen Mountain tectonic belt extrudes and lifts the premountain plain, playing a crucial role in shaping its topography. Additionally, the concealed fracture zone of Xinjin-Chengdu-Deyang may have contributed to surface subsidence. (4) After eliminating the effect of human factors, the cultivated land and grass land cover types exhibit a subsided state, whilst the artificial surface deformation is relatively stable, and the forest land exhibits an uplifted state. Surface deformation on different land cover types is correlated with water permeability, but it is also influenced by other factors. [ABSTRACT FROM AUTHOR]

This preliminary study aims at reconstructing the life history, including dietary patterns, mobility, and health conditions, of a high‐class noblewoman (M154) from the late Shu state (晚蜀), the period of Kai Ming regime (開明氏), in the Shuangyuan Village Cemetery of the Eastern Zhou period (770–221 BC), Chengdu Plain, China, as a way to provide a glimpse into the human lifeway in the late Shu culture period under the impact of non‐local cultures. We combined skeletal pathological observations with multi‐isotope (carbon, nitrogen, and oxygen) analyses of bone collagen, enamel, and dentin serial sections and analyzed multi‐tooth enamel from the remaining 10 humans in the cemetery as comparative data. The results suggest that the occupant of M154, a female who died at around 30 years of age, consumed mainly rice (C3‐based crop) and high animal protein throughout her life, was weaned at 2–3 years of age, experienced physiological stresses after weaning and at 7–8 years of age but recovered from both rapidly (less than a year), which probably was related to better care, and that the timing of physiological stress embodied in isotopic profiles from incremental dentin sections is consistent with the observed enamel hypoplasia and cribra orbitalia. She more likely lived with the local population from childhood to adolescence and did not experience long‐distance migrations. After 7–8 years of age, she consumed relatively stable food resources and lived a stable life until death. Here, we show the stable and well‐cared‐for life history of a high‐ranking noble of the late Shu state, providing new insights into the study of the ancient Shu people and a reference for further research. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Inorganic Analytical Chemistry / Zhongguo Wuji Fenxi Huaxue is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the economic center and major grain-producing area in Southwest China, the calculation of the carbon budget and the protection of cultivated land in the Chengdu Plain are of vital significance for China to achieve a carbon peak strategy and ensure food security. For the purpose of clarifying the trend of land use focus and carbon emissions in the Chengdu Plain, the carbon peak level of land use in 33 counties in the Chengdu Plain was explored. Based on the gravity center model and IPCC carbon emission coefficient method, the changing trend of land use gravity center and carbon emission in Chengdu Plain from 2006 to 2022 was clarified. PLS regression model and LMDI model were used to explore the main influencing factors of the carbon emission of cropland and the carbon emission of building land. PLUS model was used to simulate future land use patterns and carbon emissions. (1) The center of gravity of cropland, building land, water, and other and unused land shifted to the northeast by 4.23 km, 5.46 km, 8.44 km, and 31.58 km, respectively, and that of forest and grass shifted to the southeast by 11.12 km and 3.41 km, respectively. For major food crops, the centers of gravity of rice and maize moved northeastward by 15.47 km and 7.52 km, respectively, while wheat moved southwestward by 17.77 km. (2) From 2006 to 2022, carbon emissions from land use in the 33 counties of the Chengdu Plain are all on the rise, with a total increase of 13.552 million tons, and carbon sinks in the 31 counties continue to decline, with a total decrease of 0.691 million tons. (3) Under the natural scenario, carbon sink scenario, and carbon reduction scenario, the carbon emissions from land use decrease by 0.5391 million tons, 3.4728 million tons, and 4.5265 million tons from 2022, respectively. Among the 33 counties in the Chengdu Plain, 11 counties did not achieve carbon peak under the natural scenario, 5 counties did not achieve carbon peak under the carbon sink scenario, and all the counties achieved carbon peak under the carbon sink scenario. During the study period, there was a serious loss of cropland in the Chengdu Plain, mainly to building land in the central part of the Chengdu Plain and to forests within the Longmen Mountain, Longquan Mountain, and Leshan City, and there is a need to strengthen cropland protection in this region in the future. Under the natural scenario, carbon sink scenario, and carbon reduction scenario, land use in the Chengdu Plain region can achieve carbon peak, and the carbon reduction model will be more helpful for the counties to achieve carbon peak.

To grasp the characteristics of changes in regional soil available potassium（AK）content and its influencing factors, 184 points sampled during the second national soil survey in the 1980s and 176 points sampled during 2016—2017 were selected in the Chengdu Plain. The characteristics of soil available K content changes in the surface layer（0–20 cm）of agricultural land in the Chengdu Plain and its relationship with the transformation of agricultural land use mode and parent material type in the past 40 years were explored by general statistics and one-way analysis of variance（ANOVA）. The results showed that the available K content in the surface soil of agricultural land increased from 44.44 mg·kg-1 to 57.24 mg·kg-1 in the study area, and the increase was significant（28.80%, P<0.05）. Compared with the traditional rice-wheat/ oil rotation in the 1980s, the available K content of the topsoil of rice-vegetable and rice-wheat/ oil rotations increased by 103.83%（P<0.05）and 17.64%, respectively, while the available K in the surface soil of garden land decreased by 11.95%. In different parent material types, the available K content in the soil surface layer developed by gray-brown alluvium was the highest, at 82.08%（P<0.05）, followed by Pleistocene old alluvium（25.48%）and gray alluvium（9.82%）. Compared with the traditional rice-wheat/oil rotation, the increase in soil available K accumulation in gray-brown alluvial development under rice-vegetable rotation（135.96%, P< 0.05）was much higher than that of Pleistocene old alluvium（116.04%, P<0.05）and gray alluvium（79.30%, P<0.05）. Additionally, garden land only increased the available K accumulation in gray-brown alluvium and Pleistocene old alluvial soil, and reduced available K accumulation in gray alluvial soil. This shows that changes in farmland use mode change the characteristics of available K accumulation in the surface soil in the study area, but their influence on the accumulation depends on the type of parent material. [ABSTRACT FROM AUTHOR]

The Jiangkou site is located in the Min River channel in Pengshan County, Sichuan Province, China. One hundred and four bronze weapons and tools of the First millennium to the second century BCE were found throughout five excavations from 2016 to 2022. Typology and radiocarbon dating suggest that the bronze objects could be dated as early as the early Western Zhou dynasty. There is a great variety of object types, and some types have not been discovered before. In order to study the technical characteristics and the sources of raw materials of these bronze objects, through analysis of observation of the wood handles in the socket of the axes and alloy composition, we found that the wood handles were most likely sourced locally, and the people at that time consciously chose tree species suitable for tool and agricultural implement handles. Compositional analysis shows that Jiangkou bronzes have diachronic differences in alloy compositions, Western Zhou bronzes exhibited the highest copper content, with lower lead and tin content, but the copper content in the bronzes of the Eastern Zhou dynasty declined significantly, while lead and tin content increased to varying degrees. Furthermore, the alloy compositions of the Jiangkou bronzes were directly related to their forms and functions. The lead isotope study indicates that the copper materials used in the Western Zhou bronzes from Jiangkou were found to be diverse, including both Central Plains-type materials and local materials. Moreover, six bronzes displayed highly radiogenic lead. Compared with the Western Zhou bronzes, the lead isotope ratios of Eastern Zhou bronzes from Jiangkou site are more concentrated, some of the copper used in Eastern Zhou bronzes may have originated from local sources in Sichuan. Through scientific analysis, this research provides new understandings and a new perspective for the study of early bronzes in the Chengdu Plain. [ABSTRACT FROM AUTHOR]

The Homegarden (HG) in Chengdu Plain is an important agricultural heritage in China, and is viewed as a sustainable land use pattern. HGs are damaged continuously under the backdrop of urbanization and land use changes, thus influencing ecosystem services and residents' welfare. This study investigates the distribution characteristics of HGs in Chengdu and their ecosystem service value and proposes HG protection strategies on this basis. Results demonstrate that (1) there are 71,892 HGs in Chengdu, covering an area of 558.70 km2. The average density is 9.94 HGs/km2. (2) The total ecosystem service value of HGs is about USD 30562.70 million/year. Among them, the material product, regulating services, biodiversity maintenance value, and cultural services account for 15.46%, 37.90%, 14.19%, and 32.45%, respectively. (3) The number, area, and ecosystem service value of HGs in Chengdu decreased by 11.45%, 20.89%, and 6.92% in the last ten years, respectively. (4) The area of the extremely important protection zone of HGs accounts for 21.14%. We suggest giving priority attention to these areas. Protection strategies of HGs include, among others, formulating HG protection plans, keeping traditional features, maintaining biodiversity, and increasing the economic income of residents. [ABSTRACT FROM AUTHOR]

Domestic sewage is an important source of surface water pollution in the rural areas of developing countries, especially in the rural areas of China. In recent years, with the strategy of rural revitalization, China has paid increasing attention to the treatment of rural domestic sewage. Therefore, 16 villages in the Chengdu Plain were selected for the study, and seven indicators were analyzed and evaluated, including pH, five-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP), suspended solids (SS) and total nitrogen (TN), in the water samples at the inlet and outlet of the wastewater treatment plant. The concentration of each pollutant in the rural scattered domestic sewage of the Chengdu Plain in Southwest China was obtained, and the concentration of each pollutant in domestic sewage was higher than that in summer. In addition, the preferred process for removing each pollutant was obtained by studying the effects of the treatment process, season and hydraulic retention time on the removal efficiency of each pollutant. The research results provide valuable references for the planning and process selection of rural domestic sewage treatment. HIGHLIGHTS Comparative analysis of the concentration of rural domestic sewage before entering and after leaving the wastewater treatment plant in the Chengdu Plain.; The concept and calculation method of the ‘α’ was proposed.; System removal efficiency (SRE) was used in the selection of optimal sewage treatment plants.; The most suitable removal process for each pollutant is proposed.;

The analysis of the surface ozone pollution in 8 cities in the Chengdu Plain urban agglomeration during the summer of 2015 to 2019 showed that the O3 pollution area in plain has expanded in the summer of the past 5 years.The 90th percentile concentration of O3_8 h and O3 over-standard days in Chengdu are both the largest， Ya'an and Mianyang have lower concentrations but a significant upward trend.Using PCT objective weather classification method， the geopotential height field of different layers over Chengdu Plain and its surrounding were objectively classified in the summer for the past five years， the results showed that： （1）The 700 hPa ozone pollution weather classification was the high pressure system type， and the 500 hPa was the rear of the westerly trough and the flat vertical zonal type， and the 100 hPa was the central and eastern of asia high type； （2）The high and low altitude weather conditions of the typical ozone pollution process in the summer of the past 5 years are divided into the rear of the westerly trough， high pressure development and high pressure control type.During the pollution process， Chengdu Plain is mostly affected by the northwest airflow behind the westerly trough or the sinking airflow near the ridge of the subtropical high pressure； （3）The polluted weather pattern had the characteristics of high temperature and low humidity， strong radiation in small winds， and high mixed layer during the day.The effects of airflow subsidence and warming and local circulation inhibit the diffusion of pollutants to upper layers， and promote the downward transmission of O3 in the upper boundary layer and accumulation in the Chengdu Plain.Using HYSPLIT backward trajectory model and potential source contribution analysis （PSCF）， explored the trajectory clustering and potential source areas of different weather patterns that affect the O3 concentration in the Chengdu Plain.The results showed that the local and transportations among cities in the Sichuan Basin contribute to the ozone pollution.The most important potential source of ozone is located in the local urban area.The main potential source areas of Chengdu， Meishan and Ziyang are also concentrated in northern Sichuan and western Chongqing， while the main source of Deyang is concentrated in Chengdu and Meishan.The rear of the westerly trough and high-pressure development， the regional transport of ozone is more obvious， and high-pressure control type shows significant local accumulation.

This study analyzes the nitrogen isotope composition of individual amino acids in collagen extracted from human bone samples from the Gaoshan, Yingpanshan, and Xinyicun sites in Sichuan, where the isotope baseline is unavailable or incomparable with the isotopic data derived from human remains. It aims to understand the food compositions of the inhabitants at these sites, spanning the period from the late Neolithic to the middle Bronze Age, during which time agriculture and domestication of animals were introduced to the region and became increasingly important. The δ15N values of two amino acids, phenylalanine (δ15NPhe) and glutamic acid (δ15NGlu), indicate that the peoples on the Chengdu Plain mainly consumed terrestrial foods. The contribution of aquatic resources to their diet was limited. A possible explanation for the low dependence on aquatic foods is that the developed agriculture and domestication of animals offered sufficient foods. Such subsistence economies and dietary patterns were shaped in the early Baodun period (ca. 2,500–2000 BCE) at the latest and did not seem to change when transiting to the Bronze Age. This study also assesses the significance of these subsistence practices in supporting the social development of the Chengdu Plain. [ABSTRACT FROM AUTHOR]

Copyright of Plateau Meteorology is the property of Plateau Meteorology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Traditional rural homegarden agroforestry system in the Chengdu Plain of China, called “Linpan” in Chinese, integrates the ecological functions of the landscape with human production activities. Studying the driving mechanisms of rural landscape changes in the Chengdu Plain is of great significance from stakeholders’ perspective. Taking the Pidu Linpan Farming System (PLFS) in the suburban area of Chengdu (designated as one of China-Nationally Important Agricultural Heritage Systems in 2020) as a case, this study combined remote sensing image analysis, oral history interviews, and focus group interviews to elucidate the driving forces of landscape changes in the PLFS. The results show that tourism development, traffic accessibility, economic demand, and agricultural heritage protection measure are the main driving forces promoting the stability and maintenance of the traditional homegardens. In contrast, population ageing, land circulation, centralized residence, climate change, and living and recreational need are the forces leading to adverse changes in the traditional homegardens. In addition, these driving forces have led to the gradual abandonment of traditional agricultural activities and critical issues related to rural landscape planning and management. The current research indicates that infrastructure construction and increased traditional agricultural income are considered as the best practices of local stakeholders, promoting the development of the protected homegardens of heritage sites and tourist destinations. Finally, we put forward some suggestions to improve and maintain the traditional rural landscape: (1) establishing a benefit-sharing mechanism; (2) establishing a training system with traditional technology and culture; (3) strengthening infrastructure construction; (4) promoting the development of the agricultural industry; (5) improving the cultural quality of farmers; and (6) establishing a management system with legal effects. This research can provide a basis for the formulation of rural landscape planning and the orderly and healthy development of agricultural heritage in Chengdu Plain.

Environmental pollution caused by rapid industrial activities are becoming increasingly drastic, particularly its impact on soil and plant health. The present study was conducted to investigate the heavy metal (loid) (As, Cd, Cu, Hg, Pb, and Zn) concentrations in soils and food biomass crops and estimate the potential health risks of metals to humans via consumption of contaminated food biomass crops from Shifang, a periurban agricultural areas in the Chengdu Plain, Sichuan, China. Results revealed that the soils have been experiencing a substantial accumulation of heavy metals, especially for Cd, with a mean of 0.84 mg kg−1, about six times higher than the background values, of which 98% exceeded the pollution warning threshold of the China Soil Environmental Quality Standards. A total of 78% of all the grain part failed the national food standard for Cd. No significantly positive relationships between metal levels in food biomass crops and in the corresponding soils, indicated metals enrichment in soils were not entirely reflected to crops contaminant burdens. Estimated daily intake (EDI) of all the metals except for Pb, exceeded the oral reference dose (RfD) or the minimal risk levels recommended by USEPA and ATSDR. Target hazard quotients (THQs) of all the metals except for Cd was less than one indicated that potential health risk to the local inhabitant originated mainly from Cd exposure via cereals consumption. Mitigation strategies to curtail Cd-contaminated soils and crops Cd burdens need careful tailoring to meet the needs of health and safety in this region.

In this study, we echo the call from the UN to interpret Sustainable Development Goals (SDGs) in their regional context—in this case, the linpan (wooded lot) landscape of the Chengdu Plain, in Sichuan, China, where the shocks and stresses of recent, rapid administrative-economic urbanization are testing the resilience of some of the world's most sustainably productive and long- and densely-settled agrarian environments. In recent years, fine-grained information and communications technology (ICT) governance tools in Chengdu, such as “grid management”, present opportunities to sustain and scale up the collection of data necessary to validate and refine indicators of landscape resilience, and use them to regulate development, in accordance with SDG goal 11 to enhance legislation, governance, and capacity via information gathering and sharing. ICT-based governance in combination with traditional place-based knowledge can play a critical role in ensuring the resilience of urban-rural co-development. To realize this potential, however, ICT-enabled governance needs to incorporate greater transparency and more local feedback loops and enable greater participation from older farmers and women, to inform household and community-level land-use choices and initiatives. It also needs to link regulatory functions with marketing and pricing functions so that farmers may benefit from the sustainable practices they are encouraged to adopt.

The Homegarden (HG) in Chengdu Plain is an important agricultural heritage in China, and is viewed as a sustainable land use pattern. HGs are damaged continuously under the backdrop of urbanization and land use changes, thus influencing ecosystem services and residents’ welfare. This study investigates the distribution characteristics of HGs in Chengdu and their ecosystem service value and proposes HG protection strategies on this basis. Results demonstrate that (1) there are 71,892 HGs in Chengdu, covering an area of 558.70 km2. The average density is 9.94 HGs/km2. (2) The total ecosystem service value of HGs is about USD 30562.70 million/year. Among them, the material product, regulating services, biodiversity maintenance value, and cultural services account for 15.46%, 37.90%, 14.19%, and 32.45%, respectively. (3) The number, area, and ecosystem service value of HGs in Chengdu decreased by 11.45%, 20.89%, and 6.92% in the last ten years, respectively. (4) The area of the extremely important protection zone of HGs accounts for 21.14%. We suggest giving priority attention to these areas. Protection strategies of HGs include, among others, formulating HG protection plans, keeping traditional features, maintaining biodiversity, and increasing the economic income of residents.

In this study, we conducted carbon, strontium, and oxygen isotope analyses on tooth enamel from human and pig remains that were excavated from the Chengdu Plain and its western highlands in Sichuan to investigate the dietary patterns of the peoples and possible population movements in these areas. The analyses of carbon isotope showed that the dietary patterns in these areas support our previous understanding that, while rice was an important food source for the peoples on the Chengdu Plain, millets played a crucial role at the mountainous sites. Moreover, the same dietary patterns in these two regions lasted from the late Neolithic Age to at least the Bronze Age. The result of strontium analyses suggests that the bioavailable strontium baseline of the Chengdu Plain is 0.71197–0.71400. Based on this strontium ratio and δ13C value ranges derived in this study, several unusual cases were identified. We also note an interesting difference in the oxygen isotope values between the late Neolithic and the early Bronze Age sites, which we suspect to be related to climate change in around 2000 BC. This finding, however, requires more data for verification. Overall, this is the first time isotopic analysis was used to test human and faunal remains in a more extensive manner and to enhance our understanding of the paleodietary patterns, human dynamics, and climatic changes in ancient Sichuan. The results provide information about the sites when other sources of evidence are lacking and suggest a baseline for future comparisons. [ABSTRACT FROM AUTHOR]

PM 2.5 remains one of the critical pollutants involving regional and complex air pollution in many big cities of China, and its improvement has become sluggish in recent years. In this study, we collected PM 2.5 samples from two cities, Chengdu and Ya'an, which have different industrial structures in the Sichuan basin during wintertime and investigated the reasons behind their severe PM 2.5 pollution. Throughout the entire sampling period, the average PM 2.5 concentrations in Chengdu (71.3 ± 24.8 μg/m3) and Ya'an (72.6 ± 27.1 μg/m3) were similar. However, the chemical compositions of PM 2.5 showed significant differences. Chengdu exhibited higher concentrations of water-soluble inorganic ions, whereas Ya'an had higher levels of carbonaceous compounds. Both cities experienced an ammonium-rich environment, which promoted the homogeneous generation of secondary pollutants. Moreover, as PM 2.5 pollution worsened, the influence of heterogeneous reactions involving SO 2 and NOx, as well as the heterogeneous hydrolysis of N 2 O 5 , gradually became more pronounced in particle formation. Additionally, adverse meteorological conditions facilitated pollutant accumulation in Ya'an. Using the Positive Matrix Factorization model, we identified 5 sources of PM 2.5. The primary source of PM 2.5 in both cities was secondary formation (35.4% in Chengdu and 32.5% in Ya'an), while their second-largest contributors varied (26.2% from vehicle emission in Chengdu, and 26.6% from combustion source in Ya'an). These discrepancies highlight the necessity for tailored government interventions, particularly during the winter season. By analyzing the light absorption of the carbonaceous at 370 nm, we discovered that brown carbon was the primary absorber of near-ultraviolet light, with vehicle emissions accounting for the largest portion in Chengdu (37.2%) and combustion emissions being the predominant factor in Ya'an (51.0%). These results could potentially help for having a long-term impact on climate change by simultaneously reducing PM 2.5 pollution. [Display omitted] • Unfavorable weather conditions resulted in the accumulation of pollutants in Ya'an. • Secondary pollutant formation in the study areas was primarily driven by heterogeneous reactions. • The absorption of BrC at 370 nm was significantly influenced by vehicle emissions and combustion. [ABSTRACT FROM AUTHOR]

Several studies have examined the role of changes in the natural and anthropogenic factors of soil heavy metals; however, the causes of spatial heterogeneity of soil heavy metals remains to be understood. To study heavy metals in soil, we collected a total of 134 soil samples from diverse land-use types; whereby we measured the concentrations of six metals (Cr, Ni, Cu, Zn, As, and Pb). Herein, we used Kriging interpolation methods in a geographic information system (GIS) and geo-accumulation index to map the distribution and evaluate the pollution of heavy metals in soil. We applied geographic detector models, a new spatial statistical method, to determine how the dominant factors and interactions led to spatial heterogeneity of heavy metal variations in soil, in the northern Chengdu Plain in western China. The results indicated that the overall pollution of heavy metals in soil was relatively light, with Cr, Ni, Cu, Zn, As, and Pb in soil reaching 5.37%, 22.15%, 22.82%, 17.45%, 4.70%, and 27.52%, respectively. We observed that heavy metals in soil demonstrated significant spatial heterogeneity, with high Cr and Ni contents in the central region and low in the south and north; Cu was high and widely distributed in the western parts, exceeding the background value; Zn was high in the north and west, and low in the east, covering a wide area with significantly high contents; As was high in the west and central parts, and low in the north, south, and east; Pb was high in the north and central parts, and low in the south. The results revealed that the dominant factors affecting the spatial heterogeneity of Cr in soil were moisture content, available phosphate, and distance to factory; the explanatory power was 31.52%, 25.77%, and 10.71%, respectively. Moisture content, organic matter, and available phosphate most significantly influenced Cu and Pb in soil, with explanatory powers of 13.11%, 8.20%, 3.21%, 10.55%, 10.49%, and 11.87%, respectively. The available phosphate, moisture content, and soil type can explain the spatial heterogeneity of Zn in soil, with explanatory powers of 31.52%, 2 5.77%, and 10.71%, respectively; whereas the dominant factors affecting the spatial heterogeneity of As in soil were soil type, slope, and geomorphic type, with explanatory powers of 16.11%, 6.68%, and 6.40%, respectively. Moisture content, soil type, and GDP had the greatest influence on Ni in soil, with explanatory powers of 1.4%, 0.77%, and 0.62%, respectively. This study suggests that the interactions among impact factors mutually and non-linearly enhance the impact of a single factor on the spatial heterogeneity of soil heavy metals. Our research highlights that the geodetector method is an effective approach to disentangle the complicated driving factors and reveal the optimum characteristics and ranges of each factor, further contributing to our understanding of the spatial heterogeneity of soil heavy metals and the driving mechanisms. Our results are useful for providing theoretical contributions and practical references to accelerate the formulation of land pollution management policies. [ABSTRACT FROM AUTHOR]

Freshwater systems are important sources of greenhouse gases (CO2, CH4, N2O) in the atmosphere, but their contributions to the regional GHGs budgets remain uncertain due to numerous types, complex carbon and nitrogen cycle processes, and human disturbance. This study monitored the concentrations and fluxes of CO2, CH4 and N2O in different inland waters including rivers, irrigation canals, reservoirs and ponds in Chengdu Plain (Xinjin District), so as to explore the characteristics and influencing factors of greenhouse gas emission in different inland waters in Chengdu Plain. The total evasions of CO2, CH4 and N2O from different types of waters were estimated. The results showed that the concentrations of carbon, nitrogen and phosphorus vary significantly in different inland waters with the highest level found in pond systems and polluted river sections, followed by the irrigation canals and the generally lower values detected in reservoirs and rivers. It was suggested that pollution load is higher in artificial waters. The dissolved CO2, CH4, N2O concentrations in all inland waters ranged from 15.7-153.1 µmol L-1, 0.099-0.986 µmol L-1 and 0.016-0.354 µmol L-1, respectively. And, CO2, CH4 and N2O concentrations in artificial irrigation canals, ponds and polluted rivers were significantly higher than those in the unpolluted rivers and reservoirs. The estimation of greenhouse gas fluxes based on the boundary layer method showed that the CO2 fluxes from irrigation canals were the highest (197 ± 52 mmol m-2 d-1), followed by ponds (114.04 ± 42.20 mmol m-2 d-2), rivers (65.49 ± 50.70 mmol m-2 d-2), reservoirs (22 ± 30 mmol m-2 d-1); the CH4 and N2O fluxes from irrigation canals and ponds were the highest, approximately 2~3 times those from rivers and reservoirs; the greenhouse gases fluxes from seriously polluted rivers were also higher than these from other unpolluted rivers. Based on the extrapolation method, the total greenhouse gas evasions from inland waters in Xinjin District were estimated as 2.5 × 104 t CO2 y-1, 107 t CH4 y-1 and 69 t N2O y-1, whose CO2 equivalent converted was about 5.0 × 104 t y-1 according to the global warming potential. The greenhouse gas fluxes from irrigation canals, ponds, reservoirs and rivers accounted for 19%, 24%, 1% and 56% of the total evasion from all inland water in Xinjin District, respectively. The irrigation canals and ponds had small water areas but showed high greenhouse gas emissions. The regression analysis showed that the concentrations and fluxes of CO2, CH4, N2O were positively correlated with the conductivity and carbon, nitrogen and phosphorus concentrations, while negatively correlated with dissolved oxygen. The abundance of biogenic elements in freshwater and water pollution are crucial to the greenhouse gas fluxes, particularly, human activities have an obvious influence on greenhouse gas emissions from different in land waters. [ABSTRACT FROM AUTHOR]

[Objective] Measuring and analyzing the evolution characteristics and driving mechanism of the land space pattern can not only reveal the spatiotemporal evolution of the land space pattern, but also provide a theoretical basis for optimizing the regional land space structure. [Methods] Based on the multi-functional perspective of the "Sansheng" space, this paper divides the land types of Chengdu Plain in the third phase from 2000 to 2018. First, using the transfer matrix and dynamics method, explore the spatial structure of the Chengdu Plain's land spatial structure changes in time ; Then use the geo-information atlas method, standard deviation ellipse and the center of gravity migration model to analyze the evolution of the spatial pattern of the Chengdu Plain in time and space; finally, with the help of the geo-detector model, reveal the characteristics of the driving force of the spatial pattern of the Chengdu Plain. [Results] (1) From 2000 to 2018, the area of production ecological space in the Chengdu Plain decreased by 174 108 hm², and the area of living and production space increased by 73 806.3 hm², of which the degree of land space change in Chengdu Plain from 2000 to 2010 was overall higher than that in 2010-2018 year. (2) From 2000 to 2018, the area of ecological space transferred to production ecological space was the largest, with a transfer area of ​​2410.03 hm², followed by the transfer of ecological production space to ecological space, with a transfer area of ​​2310.74 hm² The areas with higher dynamics are located in the middle of the study area, and more than 50% of the districts and counties have dynamics below 1.2. (3) From 2000 to 2018, the stable land area accounted for 91.09% of the total area of the study area, and the early change type accounted for 5.49%, mainly distributed in the central city of Chengdu, Mianyang and Ya'an; the later change type and the change type were respectively Accounted for 3.04% and 0.38%. (4) From 2000 to 2018, the standard deviation ellipse area and flatness of the production space in the study area increased, the length of the major axis decreased, and its center of gravity shifted to the northeast; the length of the major axis and the length of the minor axis of the living space both showed an increasing trend, and the angle of rotation Decrease; the ecological space standard deviation ellipse shows the characteristics of decreasing flatness. (5) Socio-economic factors are the dominant factors in the land and space changes of the Chengdu Plain. Its population density q is the highest, which is 0.7816; the interaction between the driving factors is nonlinear and strengthened, among which the interactive effect of population density and road network density The strongest is 0.8646. [Conclusion] Coordinating the contradictions and conflicts between various land uses and reducing the transformation of land used by human activities is a necessary way to optimize the land space of Chengdu Plain and achieve sustainable development. [ABSTRACT FROM AUTHOR]

Objectives: We undertook a more comprehensive analyses than our previous study (Yi et al., International Journal of Osteoarchaeology, 2018, 28, 636–644) at the Gaoshan site (~2500–2000 cal. BC) to expand our understanding of the different roles of rice and millets to human subsistence strategies, diachronic shift of human diets, diversity of human life histories and cultural influence (dental ablation) to human population. Materials and Methods: Carbon and nitrogen isotopic analyses of human (ribs and long bones, n = 68) and animal (n = 15) bones as well as carbonized seeds from rice and millets (n = 8) were undertaken. Human bones were directly AMS‐14C dated. In addition, sequential sampling of 16 individuals with varied age and sex and cultural contexts for isotopic analysis was also conducted. Results: The calibrated dating results (n = 27) indicate that there existed two periods of occupation at the site, ~2500–2200 BC and ~2200–1900 BC. Moderate high δ15N values were found in the crops. Isotopic data from bone collagen suggest that the humans mainly relied on C3‐based animal protein and were supplemented by C4‐based foods. This isotopic pattern is also seen in pigs. Significant difference of human δ13C values (Mann–Whitney U test, p < 0.05) between the two periods was observed. Compared to the bones, the isotopic data of human dentine serial sections show a much wider variability and higher δ13C values. Discussion: The crops (millets and rice) were probably manured. Human individuals subsisted on rice/millet agriculture and pigs in general. In combination with the radiocarbon dates, the increase of C3 (rice) consumption by the humans was found from the early (2500–2200 cal. BC) to late (2200–2000 cal. BC) periods, indicating the intensification of rice agriculture through time. However, four categories of human life histories during childhood are identified given different isotopic profiles of dentine sections, demonstrating that C3 (rice) and C4 (millets)‐based foods played different roles in human lives. Even though, there were similar weaning practices among the human populations. It is surprising that human individuals with dental ablation, cultural characteristic in the Middle and Lower Yangtze River Valley, consumed more millets during childhood in the early period than those without dental ablation in the late period. Our study here provides novel insights into cultural dynamics and the interplay between rice and millets in rice‐millet agricultural system during the Late Neolithic in Southwest China. [ABSTRACT FROM AUTHOR]

The Chengdu Plain was the iron production center in southwest China in the Han dynasty (202 BC-220 AD), which three iron smelting sites and large amounts of iron objects were excavated in the past decades. However, metallurgical studies of iron production in the Chengdu Plain have been overlooked for a long time. This paper provides an opportunity to understand the iron production technology in the Chengdu Plain in the Han dynasty. The metallurgical analyses of excavated iron objects from the Baozishan cemetery site show that most iron tools and weapons were forged from decarburized iron and fined iron. Besides, carburization, decarburization, and quenching techniques were used to control the malleability of iron objects. According to the results, the primary use of iron at Baozishan was forged wrought iron and steel, which evidenced that forging technique played an important role in the Chengdu Plain in the Han dynasty. [ABSTRACT FROM AUTHOR]

Soil bulk density is a basic but important physic soil property related to soil porosity, soil moisture and hydraulic conductivity, which is crucial to soil quality assessment and land use management. In this study, we evaluated the spatial variability of soil bulk density in the 0–20, 20–40, 40–60 and 60–100 cm layers as well as its affecting factors in Southwest China's agricultural intensive area. Results indicated the mean value of surface soil bulk density (0–20 cm) was 1.26 g cm−3, significantly lower than that of subsoil (20–100 cm). No statistical difference existed among the subsoil with a mean soil bulk density of 1.54 g cm−3. Spatially, soil bulk density played a similar spatial pattern in soil profile, whereas obvious differences were found in details. The nugget effects for soil bulk density in the 0–20 and 20–40 cm layers were 27.22 and 27.02% while 12.06 and 3.46% in the 40–60 and 60–100 cm layers, respectively, gradually decreasing in the soil profile, indicating that the spatial variability of soil bulk density above 40 cm was affected by structural and random factors while dominated by structural factors under 40 cm. Soil organic matter was the controlling factor on the spatial variability of soil bulk density in each layer. Land use and elevation were another two dominated factor controlling the spatial variability of soil bulk density in the 0–20 and 40–60 cm layers, respectively. Soil genus was one of the dominated factors controlling the spatial variability of soil bulk below 40 cm.

Farmland is one of the most important ecosystems in the world, providing foods and habitats for humans as well as many wild animals. However, biodiversity in farmlands has been substantially impacted by the intensification of agriculture and changes in landscape. Increasing either the area of natural and semi-natural habitat or the proportion of biodiversity-friendly crops could potentially mitigate the decline of biodiversity, but at the same time they would affect the agricultural economic output and were not widely applied. To date, some studies have focused on whether crops or cropland heterogeneity has a positive impact on biodiversity, but the results were inconsistent and it is difficult to summarize the relationship between farmland heterogeneity and farmland biodiversity in general. Meanwhile, few papers have studied the differences in bird diversity among small-scale agriculture in China. We conducted a year-long field survey on the Chengdu Plain to explore the relationships of landscape composition and the heterogeneity of cropland and non-cropland with bird diversity and community structure across different seasons. Using generalized linear models (GLM) and generalized least squares (GLS) for data analysis, our results showed that bird diversity is positively correlated with natural woodlands but negatively correlated with commercial forests. Both crop and non-crop landscape compositional heterogeneity affect bird diversity and community structure, especially during the non-breeding season, as many high-altitude birds come down to the farmland for foraging. Both bird diversity and community structure are influenced by cropland configurational heterogeneity, but seldomly influenced by non-cropland configurational heterogeneity. We propose to maintain the area of natural habitat and increase the area of mixed commercial forests by replacing monocultures. Diversified crop and non-crop types with a reasonable layout could conserve farmland biodiversity and maintain the stability of local ecosystems. More research on landscape heterogeneity in small-scale agriculture is needed to provide better understanding of the relationship between the agricultural landscape and bird diversity.

Purpose: Being the most widespread soil in the Chengdu Plain in Sichuan Basin, China, paddy soil has a great importance in agriculture and ecology. Anthropogenic activities alter the concentrations and stoichiometric ratios (C:N, C:P, and N:P) of carbon (C), nitrogen (N), and phosphorus (P) in paddy soil. This study aims to investigate whether the cycling of C, N, and P in paddy soil is influenced by cropping system and pedogenic process (the subtype of paddy soil). Materials and methods: In this study, we collected 1080 soil samples at 0–20 cm from five cropping systems (rice monoculture (RM), vegetable monoculture (VM), rice and vegetable rotation (RVR), rice and wheat rotation (RWR), rice and oilseed rape rotation (ROR)) and six subtypes (bleached paddy soil (BPS), gleyed paddy soil (GPS), percogenic paddy soil (PPS), degleyed paddy soil (DPS), submergienc paddy soil (SPS), and hydromorphic paddy soil (HPS)) of paddy soil in Chengdu. Soil organic carbon (SOC), soil total nitrogen (TN), and soil total phosphorus (TP) concentrations were determined to calculate the stoichiometric ratios. Results and discussion: Our results indicated that the concentrations of SOC, TN, and TP of paddy soil were higher than those of cropland on a global scale. There are similar stoichiometric ratios between paddy soil in Chengdu Plain and the cropland in the global scale. The cropping system and subtype significantly altered the soil nutrient concentrations and stoichiometric ratios. The concentrations of soil TN under rotation systems (RV, RW, and RO) were significantly higher than those of VM. The soil with the subtypes of BPS and GPS were related to low TP concentration. Conclusions: The cropping system of VM showed soil N consumption compared with the traditional cropping system (rotation systems, such as RV, RW, and RO). In addition, subtype also significantly influenced the element balance in paddy soil. The balance of soil C, N, and P is mainly affected by fertilizer application of N and P. [ABSTRACT FROM AUTHOR]

Stable isotope composition in precipitation, river water, and groundwater was used to investigate the hydrological conditions in the Pihe River catchment of Southwest China. Significant seasonal isotopic variations exist in precipitation and river water, and there is 1-month delay in the river water response to precipitation. The river water is gradually enriched under the influence of evaporation. However, due to the influence of recharge from external water source, the evaporation ratios do not strictly increase with the flow distance. The seasonal isotopic values in groundwater fluctuate the least. River water supplies groundwater more than precipitation in dry season. [ABSTRACT FROM AUTHOR]

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During the Neolithic period, the Chengdu Plain was a key region where two important crops, rice and millet, were cultivated together. Millet was probably introduced from north‐western China c.3500–3300 cal. bce, and rice came from the Middle Yangtze River c.2600 cal. bce. In this study, human and faunal remains, as well as charred crop grains, were collected from the Yingpanshan (3300–2600 cal. bce) and Gaoshan (2500–2000 cal. bce) sites where the dominant crop was millet and rice, respectively. Carbon and nitrogen isotope analyses were conducted on human bones and the ecofact samples in order to reconstruct the subsistence at the sites. The results indicate that the diets of two individuals recovered from the Yingpanshan site consisted of both C3‐ and C4‐based foods, predominantly the former. By contrast, Yingpanshan pigs consumed a large quantity of C4 fodder. This result, combined with the ecofact evidence, suggests that millet was the main crop at the Yingpanshan site. It also highlights the fact that the two Yingpanshan individuals might be non‐locals and/or belonged to later periods. On the other hand, the diet of the Gaoshan community was dominated by C3‐based foods. When considering the archaeobotanical evidence at Baodun, a site contemporaneous with and near to the Gaoshan site, it can be stated that rice was an important food resource for the Gaoshan community. This study also suggests how crops were managed at the two sites. The Yingpanshan people might have used manure for growing millet. Both manuring and irrigation might have also been practised by Gaoshan's rice farmers. However, more studies are required to understand the extent of manuring and irrigation in their agricultural economies. [ABSTRACT FROM AUTHOR]

The Baodun Culture (4600–3700 a BP) is currently the earliest archeological culture found at the Chengdu Plain in southwestern China. Archeological evidence has shown that the Baodun Culture likely originated from the upper reaches of the Minjiang River, with two possible routes for human migration into the lower Chengdu Plain proposed: (1) At about 5000 a BP, favorable climatic conditions in the upper reaches of the Minjiang stimulated the growth of populations and the development of agriculture in the region. Due to this shift, some groups expanded from the upper Minjiang River to sites in the northern area of the Chengdu Plain, such as the Guiyuanqiao site; (2) during 4800–4300 a BP, a drying event occurred in the upper regions of the river valley causing a reduction in agricultural harvests and the migration of populations into sites – including the Baodun site – from this area of the Minjiang to the southwest piedmont of the Chengdu Plain. A multi-facetted study of the T3321 profile at Baodun site, including pollens, grain size, and geochemistry, demonstrates that after 6000 a BP, the climate of the Chengdu Plain shifted from cool, toward warmer and dryer conditions. However, as the Chengdu Plain is located in an alluvial fan, hydrothermal conditions here are still generally better than those in the upper reaches of Minjiang River. A change in the proportion of Concentricystes seen in the profile T3321 also indicates that after 4700 a BP, the lake and marsh areas associated with the Baodun site further decreased. However, as a result of this reduction, more terrestrial surfaces were exposed, providing favored space for Baodun Cultural groups in the area of the site. Due to such conditions, by about 4600 cal. a BP, people in the upper reaches of the Minjiang River had primarily moved to the southwest piedmont regions of the Chengdu Plain. [ABSTRACT FROM AUTHOR]

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Chengdu Plain is one of China’s most important agricultural production zones and has a large human population. Agricultural crops require insect pollination to increase yield and quality, which is especially important in plains areas where forest area is small. Homegardens are the main habitat of pollinators. The present study identified the importance of insect pollination in homegardens in the Chengdu Plain through field investigations and comparative experiments and revealed the risk to pollination services caused by the decrease in diversity and population of managed and wild pollinators. The results showed that (1) prohibiting all insect pollination (treatment A) and prohibiting managed bee pollination (treatment B) significantly reduced the yield and seed number of rapeseed and significantly reduced the size, weight, and sweetness of peach fruit, but had no significant effects on plums; (2) the dependence on insect pollination and the economic values of insect pollination for rapeseed and peaches are 0.56 and $85.1 million and 0.44 and $31.0 million, respectively; (3) there were 23 flower-visiting pollinator species at the experimental sites including: four species of managed bees and 19 species of wild pollinators. The peak time for pollinators to visit flowers was 11:00 to 15:00, and the managed bees accounted for over 67.55% of these visits; (4) within a radius of 1000 m from the site, 58.06% of the bees were non-locally managed, and the bee population managed locally by farmers decreased; and (5) compared with 2008, the number of homegardens decreased by 17.24%, the managed bees within the homegardens decreased by 62.05%, and the disappearance and destruction of homegardens led to a significant reduction in wild pollinators. [ABSTRACT FROM AUTHOR]

Here, we present results of a pilot project that measured δ13C and δ15N values in bone collagen (ribs and femora) as well as dentin serial sections to examine individual dietary life histories at a Late Neolithic (4500 bp) site known as Gaoshan Ancient City (高山古城) located on the Chengdu Plain in Sichuan Province, China. The isotopic data of the bones indicate that humans consumed C3‐based foods, which corresponds to the dominance of rice agriculture in this region. However, the isotopic data of the dentin serial sections of five individuals display much more positive δ13C values than those of the bones, strongly suggesting that millets (a C4 crop) contributed substantially to human diets during the weaning process and early childhood. Furthermore, the isotopic profiles of dentin sections of the first molars and canines demonstrate that the cession of weaning was individually variable and completed between ~2.5 and 4 years of age. Although limited in scope, this pilot study offers new evidence of millet consumption during human growth and development even though individuals relied on rice exclusively as adults. Moreover, our study provides another perspective with which to rethink the role that millets played during the development and spread of millet agriculture to the south of China in terms of cultural exchange and migration. [ABSTRACT FROM AUTHOR]

Under G. William Skinner's theory on marketing hierarchy, "minor markets" (小市 xiaoshi) (or 么店 yao dian, "general store"), ranking below a "standard market," were closely tied to rural settlement patterns. Natural conditions on the Chengdu Plain, farmers' pursuit of convenience in farm work, and the history of the arrival and settling of immigrants to Sichuan in the early Qing dynasty combined to shape the foundation for the landscape of dispersed settlement observed by Skinner during his field study. These settlement patterns reflected not only a state of spatial dispersal, but also a relatively isolated social structure. On both a spatial and societal level, "marketing" therefore had an important integrating significance for society and the economy on the Chengdu Plain, and Skinner's theory on marketing hierarchy is furthermore in accord with the reality of the Chengdu Plain. [ABSTRACT FROM AUTHOR]

Between late 1949 and early 1950, the famed American anthropologist George William Skinner conducted a three-month social survey of Kao-tien-tzu (Gaodianzi) in the Chengdu Plain, and wrote a three-part series of papers entitled "Marketing and Social Structure in Rural China." He proposed the "standard marketing community" theory, which had a major impact on both American and Chinese Sinological studies. Many scholars have commented on this theory, raising either praise or censure, and some have adopted the theory as the basis of further studies. The author draws on archived materials and survey data on the Chengdu Plain in the Republican era to examine farmers' family income, agricultural sidelines, and relationship with rural market towns, in response to the debate over Skinner's theory. [ABSTRACT FROM AUTHOR]

The author proceeds from reconsideration of G. William Skinner's theory of the "standard marketing community" to propose an alternative understanding of a "marketing community" on the Chengdu Plain, through a concise analysis of guild halls, ancestral shrines, Buddhist and Daoist temples, academies, and other social organizations in Zhenzichang, Jian prefecture, during the Qing dynasty. The establishment of social organizations in market towns on the Chengdu Plain during the Qing dynasty was closely associated with the brokerage system and the appointment of administrative bailiffs: through the intervention of government authority, these social organizations integrated the market towns with the surrounding villages, gradually forming a community identity. Between the late 18th century and the early 19th century, a number of distinct social units centered on market towns, or marketing communities, took shape on the Chengdu Plain. The logic of "standard marketing communities" as established by Skinner is untenable: the marketing communities must be understood on the basis of the formation and significance of social organizations within the market towns. [ABSTRACT FROM AUTHOR]

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At the Jinsha site it has been discovered, through field surveys and observations of the geomorphology and sedimentology, that the direction of flow of ancient rivers, obtained through debris fabric measurement, was consistent with the direction in which buried palaeotrees had been broken, indicating that the Jinsha site possibly suffered palaeofloods. By sampling the suspected palaeoflood sediments at the Jinsha site and analysing their grain size distribution and Zr/Rb and Ba/Nb ratios, the paper discovered that the sediments tend to be composed of coarse particles, with a relatively high percentage of traction load components and saltation load components. Various samples had relatively great differences in particle size distribution; the change in the percentage content of coarse sand particles being very obvious, and the sedimentary particles exhibiting upward coarsening within the same layer. The Zr/Rb ratios and Ba/Nb ratios of the sediments reflect the changes in hydrodynamic forces within the sedimentary environment. When the hydrodynamic force was relatively weak, the Zr/Rb ratios are relatively low and the Ba/Nb ratios relatively high; whereas when the hydrodynamic force was strengthened, the Zr/Rb ratios increase and the Ba/Nb ratios decrease. On account of these sedimentological and geochemical characteristics, these sediments are judged to be palaeoflood sediments. The AMS 14 C dating results of the palaeoflood sediments shows that the period when sudden flooding occurred frequently in the Chengdu Plain was 4.0–3.6 ka BP, contemporaneous with an ancient global flooding event. This palaeoflood event probably brought about the extinction of the Baodun Culture. [ABSTRACT FROM AUTHOR]

Traditional market-towns in Chengdu Plain are blessed with rich vernacular cultural resources. In addition to summarizing characteristics of landscape image, image of downtown street and cultural symbiosis image of the traditional market-town space, this paper, based on the discussion of the renewal design of the Ancient Luodai Town, analyzes the physical elements that constitute the space image, such as the street, interface, area, node and identifiability of landmark building, so as to explore how to create the space image of the traditional market-town with distinctive vernacular cultural characteristics in the construction of the vernacular human settlements. [ABSTRACT FROM AUTHOR]

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