Spatiotemporal patterns and drivers of cultivated land conversion in Inner Mongolia Autonomous Region,northern China

Protection and optimization of cultivated land resources are of great significance to national food security.Cultivated land conversion in northern China has increased in recent years due to the industrialization and urbanization of society.However,the assessment of cultivated land conversion in this area is insufficient,posing a potential risk to cultivated land resources.This study evaluated the evolution and spatiotemporal patterns of cultivated land conversion in Inner Mongolia Autonomous Region,China,and the driving factors to improve rational utilization and to protect cultivated land resources.The spatiotemporal patterns of cultivated land conversion in Inner Mongolia were analyzed using the cultivated land conversion index,kernel density analysis,a standard deviation ellipse model,and a geographic detector.Results showed that from 2000 to 2020,the trends in cultivated land conversion area and rate in Inner Mongolia exhibited fluctuating growth,with the total area of cultivated land conversion reaching 7307.59 km^(2) at a rate of 6.69%.Spatial distribution of cultivated land conversion was primarily concentrated in the Hetao Plain,Nengjiang Plain,Liaohe Plain,and the Hohhot-Baotou-Ordos urban agglomeration.Moreover,the standard deviational ellipse of cultivated land conversion in Inner Mongolia exhibited a directional southwest-northeast-southwest-northeast distribution,with the northeast-southwest direction identified as the main driving force of spatial change in cultivated land conversion.Meanwhile,cultivated land conversion exhibited an increase-decrease-increase change process,indicating that spatial distribution of cultivated land conversion in Inner Mongolia became gradually apparent within the study period.The geographic detector results further revealed that the main driving factors of cultivated land conversion in Inner Mongolia were the share of secondary and tertiary industries and per-unit area yield of grain,with explanatory rates of 57.00%,55.00%,and 51.00%,respectively.Additionally,improved agricultural production efficiency and the coordinated development of population urbanization and industry resulted in cultivated land conversion.Collectively,the findings of this study indicated that,from 2000 to 2020,the cultivated land conversion in Inner Mongolia was significant and fluctuated in time,and had strong spatial heterogeneity.The primary drivers of these events included the effects of agriculture,population,and social economy.

Analysis on the Variation of Cultivated Land and Direct Influencing Factors During 1996 to 2006 in Zhejiang Province——Based on Land Survey Results

[Objective] The paper aimed at exploring the variation of cultivated land and influencing factors during 1996 to 2006 in Zhejiang Province more directly,comprehensively and accurately.[Method] The variation of the amount of cultivated land in Zhejiang Province and direct influencing factors had been analyzed using the land survey results of last 10 years.[Result] The cultivated land area of the whole province was reduced by 208 thousand hm2 with a decrease amplitude of 9.8%;terrain slope had played a direct role among the natural influencing factors of cultivated land variation,the cultivated land areas of flats and abrupt slopes were reduced more rapidly,while the terrace areas of gentle slopes had increased;among the social driving forces,the agricultural structure adjustment,construction land expansion and implementation of ecological restoration policy had directly led to the decline of cultivated land areas,while the strict cultivated land protection policy had slowed down the loss of cultivated land.[Conclusion] In conclusion,the declining trend of cultivated land areas is inevitable,so that more scientific general planning of land utilization and more strict land policy has to be utilized more fully in order to guarantee the social and economic development and protect the cultivated land.

Analysis of Cultivated Land Change in Hubei Province for the Last 60 Years

[Objective] The aim was to study the characteristics of land resources changes in Hubei Province in recent 60 years. [Method] By dint of historical documents,statistics and prevailed data in Hubei Province from 1949 to 2009,the temporal and spatial changes of arable land resources in Hubei Province in recent 60 years were discussed in terms of human-land relation. [Result] The amount of arable land resources in Hubei Province in recent 60 years had gone through the dynamic changes of increasing first for a short time and then continuing to decrease and then increasing stably again. Because of different natural condition and social economy,the regional differences of arable land changes were distinct. The reduction of arable resources and population worsened the relation of human being and the land,intensified the contradiction and resulted in large impact on the sustainable development of agricultural production and social economy. [Conclusion] It provided theoretical basis for the sustainable development of Hubei Province.

Temporal and Spatial Variation Characteristics of Soil Organic Carbon Content in Cultivated Land of Black Soil Region in Liaoning Province

[Objectives]To study the temporal and spatial variation of SOC content in cultivated land in black soil region in Liaoning Province.[Methods]Through the evaluation and analysis of the research data of this project and the data of the second national soil census,and using GIS technology,this paper studied the temporal and spatial variation characteristics of SOC in the black soil region of Liaoning Province,and provided a basis for improving cultivated land carbon storage and soil organic matter content.[Results]Since 1980,the SOC content in cultivated land in the black soil region in Liaoning Province has generally declined,and the spatial distribution difference has gradually decreased.From 1980 to 2018,the homogeneity of SOC distribution weakened,and the variation in a small range strengthened.The SOC content generally showed the characteristics of increase and decrease,and the changes in the area were scattered.[Conclusions]This study is of great significance to the sustainable utilization of land resources.

Design of Trinity Framework for Cultivated Land Protection

Starting with the goals and tasks of quantity,quality and ecological protection in different scales,this paper constructs a"trinity"framework of cultivated land protection system,and puts forward the key points of cultivated land protection in different scales.Finally,a preliminary evaluation is made on the quantity,quality and ecological protection of cultivated land on a macro scale in China.

County scale spatial differential characteristics of cultivated land use grade: A case of Binchuan County

Land resource is the material foundation of human survival and economic development, and the cultivated land is the essence of land resources. This paper takes the county scale, by using the method of GIS spatial analysis and statistical analysis unifies, to explore the quality of cultivated land in Binchuan County using level, and explain the utilization level of county cultivated land quality spatial differentiation characteristics. The results showed that:(1) in the quantity of cultivated land quality and utilization level, the average utilization of paddy land was greater than that of dry land, and the comprehensive utilization of cultivated land and so on. Among them, the paddy land ranged from grade 6 to 15, the average utilization was grade 11.6; dry land ranged from grade 2 to 11, the average utilization was grade 5.9; comprehensive range of cultivated land is grade 2 to 15, the average utilization was grade 8.1;(2) the quality of cultivated land utilization spatial differentiation. Paddy field, dry land and cultivated land and large value distribution in the central and southern, inverted V shape distribution; the smaller the value distribution in the East and West, a dumbbell shaped distribution. Among them, they don't use a larger value of paddy land distributed in the central, South and southwest, the maximum value is 14.3, the smaller the value distribution in the West and East, the minimum value is grade 7; the larger the value distribution by the dry land in the South and West, the maximum value is grade 10.2, the smaller the value distribution in the West and East. The minimum value is grade 2.3; the comprehensive utilization of cultivated land don't distributed larger value in the central, South and south-west, the maximum value is grade 12.7, the smaller the value distribution in the West and East, the minimum value is grade 3.5. This paper can provide scientific basis for the dynamic monitoring of cultivated land quality, the transformation of low yield farmland and the early warning of cultivated land pressure.

Cultivated land quantity niche regulation and its environmental effect

The change in the quantity of cultivated land influences the structure, function and evolvement of ecosystem. The rational change in the quantity of cultivated land will be propitious to ecological security and sustainable development, and irrational change will deteriorate ecological environment. The concept of cultivated land quantity niche regulation was firstly put forward based on niche theory and the action-feedback mechanism between cultivated land quantity niche and cultivated land benefit niche. Then, the regulation measures of cultivated land quantity niche were brought forward in rural-urban area, agro-forest area and consolidation-reclamation-exploitation area. Finally, the ecological environmental effect after regulation was analyzed. The results show that different measures should be taken to regulate cultivated land quantity niche in different areas. The economic and social benefit niche of cultivated land should be promoted to regulate cultivated land quantity niche in rural-urban area and consolidation-reclamation-exploitation area. The social benefit niche of cultivated land should be reduced in agro-forest area. The regulation goal of cultivated land quantity niche will be attained by different measures.

Spatiotemporal Variation of Cultivated Land Security and Its Drivers:The Case of Yingtan City,China

Maintaining an adequate security level of cultivated land is essential for the healthy and sustainable survival of China’s large and growing population.We constructed a cultivated land security evaluation index system,combined with an improved TOPSIS method by taking into account the balance and stability of quantitative,qualitative,and ecological security.We applied this improved method to an evaluation of the state of cultivated land security and analyzed its spatiotemporal variation in Yingtan City(Jiangxi Province,China)from 1995 to 2015.The drivers of the changes in cultivated land security were investigated via a spatial regression model,which can eliminate the effect of spatial autocorrelation.The results showed that cultivated land security decreased rapidly from 1995 to 2005,although it tended to rise slowly in the subsequent period from 2005 to 2015.Areas deemed to be in a highly dangerous state were mainly distributed in the Yuehu District,while those that were secure appeared primarily in the southern mountainous area,with the area in a generally dangerous state extending to the west in the same direction as urban development.Among the examined drivers,social-economic factors and policy factors significantly influenced the cultivated land security.Our work suggests that government managers should take appropriate measures to improve cultivated land security according to its spatiotemporal variations and the underpinning drivers in this region.

Land Consolidation with Seedling Cultivation Could Decrease Soil Microbial PLFA Diversity

The impact of land consolidation on the soil microbial PLFA diversity is of great importance for understanding the effective arable land usage,improving agricultural ecological conditions and environment.In this study,we collected the soil samples(0–20 cm)in experimental plots with 0(Z0),1(Z1a)and 4(Z4a)years of land consolidation in the forest station of Ningbo City,Zhejiang Province,southeastern China.The results were analyzed using ANOVA for randomized block design.Compared with control(Z0),the soil pH value under Z1a treatment increased by 14.6%,soil organic carbon(SOC)content decreased by 65.4%,so did the PLFA contents and relative abundance of all the microbial PLFA diversity(P<0.05),respectively.Meanwhile,for the Z1a treatment,the ratio of fungi to bacteria(F/B)significantly decreased by 35.9%(P<0.05),while the ratio of Gram-positive bacteria to Gram-negative bacteria(G+/G−)signific antly increased by 56.1%.This was strongly related to the increased soil pH values and the decrease of SOC.The Shannon index(H)and evenness index(E)of soil microbial PLFA diversity were significantly decreased after land consolidation(P<0.05).Compared to the Z1 treatment,the microbial PLFA diversity was improved slightly.Therefore,the land consolidation could significantly affect the composition of soil microbial PLFA diversity,and decrease the soil ecosystem stability.

上海新村乡土壤养分时空变异研究与耕地质量评价

以崇明区新村乡为调查区域,基于高密度采样数据,对研究区土壤有机质、水解氮、有效磷和速效钾等土壤养分进行了时空变异特征和影响因素分析。结果表明:新村乡土壤有机质、水解氮、有效磷和速效钾的平均含量分别为19.1 g∕kg、100.6 mg∕kg、14.0 mg∕kg和136.6 mg∕kg。土壤有机质和有效磷含量偏低,土壤有机质含量大于30 g∕kg的土壤仅占2.8%,土壤有效磷含量在5—10 mg∕kg的缺磷土壤占23.3%,不同点位土壤养分的时空变化差异较大。为有效推进新村乡优质米绿色生产和土壤健康,建议推行绿肥轮作休耕、养分精准管理与根际土壤调控等技术,实现新村乡农业高质量发展。

Temporal Variations and Driving Factors of Cultivated Land Use Intensity in Shandong Province from 1980 to 2015

Based on the cost-income data of agricultural products and relevant statistical data, taking major grain crops and economic crops in the process of cultivated land use as study cases, we studied characteristics of the temporal variation of cultivated land use intensity and its composition in Shandong Provinee from 1980 to 2015, and then analyzed its main driving factors. The results showed that:(1) The total intensity of major crops in Shandong Province showed a rising trend from 919.73 Yuan ha^-1 in 1980 to 3285.06 Yuan ha^-1 in 2015, and the average annual in tensity of economic crops was higher than that of grain crops. The labor cost and material cost of major crops both showed an increasing trend, but the material input was much higher than labor input for grain crops, while the labor in put was much higher tha n material in put for economic crops.(2) The labor intensity of major crops in Shandong Province showed a decreasing trend from 501.75 man-day ha^-1 in 1980 to 161.93 man-day ha^-1 in 2015. The labor intensity of grain crops was lower than that of economic crops and its decline rate was fast. On the contrary, the capital intensity showed an increasing trend from 518.33 Yuan ha^-1 in 1980 to 1159.95 Yuan ha^-1 in 2015. In the internal composition of capital internsity, the proportion of yield-increasing inputs such as seed, farm-yard manure, fertilizer, pesticide and drainage and irrigation decreased gradually, while the proportion of la-bor-saving inputs such as agricultural machinery increased significantly.(3) The cultivated land use intensity in Shandong Provinee had significant negative correlations with the amount of agricultural labor and cultivated land area per capita. The primary direct driving factor was the net income per unit cost of major crops, but the time re-sponse lagged by 1-3 years. The main indirect driving factor was the reform of agricultural policy.

Temporal and Spatial Characteristics and Optimization of the Intensive Use of Cultivated Land in Maoming City

Improving the level of intensive cultivated land use is an important measure to ensure food security and promote the sustainable development of the regional society and economy.Based on data from the statistical yearbook of Maoming City and its counties and districts from 2005 to 2018 and the land use change database of Maoming City for 2018,this study constructed an evaluation index system for four aspects:cultivated land use intensity,cultivated land use degree,cultivated land output benefit and cultivated land sustainable use status.The level of intensive use of cultivated land in Maoming City from 2004 to 2017 was evaluated by AHP,the range method and the comprehensive evaluation model,and its temporal and spatial characteristics were evaluated.The results revealed three major points.(1)The intensive use of cultivated land in Maoming City in the past 14 years was good,and its level showed an overall upward trend,with the intensive use degree of cultivated land rising from 0.4045 in 2004 to 1.3148 in 2017.(2)The levels of intensive use of cultivated land in each county and district of Maoming City were generally on the rise,with no significant differences between them.However,according to the regional distribution,the intensive use level of cultivated land was highest in Maonan District,while it was relatively low in Dianbai County.The largest increase in the level of cultivated land intensive use was in Gaozhou,and the smallest was in Dianbai County.(3)According to the existing problems of cultivated land utilization in Maoming City,combined with the current international and domestic measures to effectively improve the level of intensive use of cultivated land,four suggestions are put forward:to improve the efficiency of cultivated land utilization and effectively protect basic farmland;to improve the overall urban planning and rationally adjust the layout of construction land;to raise farmers’awareness of the intensive use of cultivated land;and to increase agricultural investment and improve agricultural infrastructure.

基于GlobeLand30数据的中国耕地与粮食生产的时空变化分析

21世纪初期,中国耕地与粮食产量变化区域差异明显,为了解21世纪初期中国耕地与粮食生产的时空变化及粮食生产对耕地面积变化的响应,该文利用2000年和2010年两期30 m分辨率的全球地表覆盖数据(Globe Land30),借助统计分析手段对2000-2010年中国耕地和粮食生产的时空变化和粮食生产对耕地面积的依赖程度进行分析。结果表明:1)中国耕地主要分布在东部地区,研究时段内,耕地与林地、草地和人工表面之间的转换最多,耕地变化的特点是"西增东减,总量减少",面积净减少了104.03万hm2,年均减少10.4万hm2。2)中国的粮食生产主要集中在东北、华北和南方地区。粮食产量变化的特点是"北增南减,总量增加"。3)中国耕地分布的集中程度会影响粮食生产的集中程度,且粮食生产分布的集中程度普遍高于耕地。中国耕地分布重心和粮食生产分布重心的移动方向相反,耕地面积的分布表现出了"南退西移"的趋势,粮食生产的重心则是"北上东移",中国的粮食生产格局已转变为"北粮南调"。4)全国有32.24%县(市)的粮食生产都表现出了对耕地数量的依赖,主要分布在东北、华北、西部、长城沿线、西南和东南沿海地区。中国耕地保护政策的制定和粮食生产的可持续发展应该遵循因地制宜的原则,在粮食生产对耕地变化敏感性高的地区,应该加强对耕地数量、质量的保护和农户种粮积极性的提高,更要重视不敏感地区耕地地力的保护和单产水平的提高,以保障中国的粮食安全。

吉林省林地林木资源核算研究

【目的】对吉林省林地林木资源实物量和价值量进行核算,摸清吉林省森林资源家底,反映吉林省林地林木资源静态状况、动态状况及其经济贡献,为吉林省科学提高森林经营管理水平,合理制定林业发展规划提供依据,也为我国开展森林资源核算研究提供实践参考。【方法】以吉林省第8次、第9次全国森林资源清查数据为实物量数据源,计算吉林省林地面积、林木蓄积存量及两次全国森林资源清查期间的变动量;结合2018年调查获得的相关成本价格数据,采用年金资本化法、重置成本法、收益净现值法、市场倒算法计算吉林省林地林木资源价值存量;采用不同核算账户分别对吉林省林地林木实物存量及其变动量以及价值存量进行列示。【结果】(1)两次全国森林资源清查期间,吉林省林地面积由856.19×10^(4) hm^(2)增加至904.79×10^(4) hm^(2),林木蓄积量由96 534.93×10^(4) m^(3)增加至105 368.45×10^(4) m^(3),分别增加了5.68%、9.15%,增幅明显。第9次全国森林资源清查期间,吉林省天然林总面积和蓄积量达616.64×10^(4) hm^(2)、89 582.59×10^(4) m^(3),同第8次全国森林资源清查期末相比,分别增加了3.90×10^(4) hm^(2)和7 673.03×10^(4) m^(3),增加了0.64%和9.37%;人工林总面积和蓄积量达177.84×10^(4) hm^(2)、11 757.47×10^(4) m^(3),同第8次全国森林资源清查期末相比,分别增加了14.11×10^(4) hm^(2)和1 309.60×10^(4) m^(3),增加了8.62%和12.53%。(2)第9次全国森林资源清查期间,吉林省林地资源资产价值为1 903.28×10^(8)元,林木资源资产价值为1 037.64×10^(8)元,共计2 940.92×10^(8)元。【结论】两次全国森林资源清查期间,吉林省林地林木资源总量不断增加,森林资源资产不断积累,不仅为当地居民带来了巨大的生态福祉,也为“绿水青山”转化为“金山银山”奠定了一定的物质基础。

建设项目用地总规模中耕地占用比例上限的确定——以陕西省为例

[目的]分析耕地资源与建设项目空间分布之间的关系,研究建设项目总规模中耕地占用比例上限的确定方法,为自然资源管理部门制定耕地保护措施提供依据。[方法]以陕西省为研究区,基于国土变更调查数据和建设项目样本数据,构建耕地密度作为指标,采用GIS空间叠加分析、地貌分区和统计参数对比方法,研究陕西省耕地密集程度分区方法,确定交通、能源、水利类单独选址建设项目总规模中的耕地占用比例上限。[结果]采用地貌分区和行政单元修订相结合的方法,以80%累计频率取值作为建设项目耕地占用比例的上限,将全省分为3个耕地密集程度区:陕北黄土高原耕地密集区、关中平原/陕南秦巴山地耕地密集区和其他区域(耕地非密集区),确定线性项目和面状项目在3个分区中的耕地占用比例上限分别为26%,42%,20%以及45%,80%,27%。建设项目总规模中的耕地占用比例在耕地密集区明显高于非密集区,呈现出耕地密度越大建设项目耕地占用比例越高的变化规律。[结论]通过确定建设项目耕地占用比例上限阈值,可使各类项目的耕地节约率达1.2%~17.9%,在保障项目用地的同时能够控制13.9%~22.5%的建设项目过度占用耕地,达到有效保护耕地的效果。

中国式现代化进程中耕地保护数量型指标的规范构造

耕地保护现代化是中国式现代化宏大叙事的一种践行样态。有必要梳理耕地保护条款的指标要素型规范架构,为耕地保护行为提供一套符合中国式现代化规范逻辑的标准化评判工具。旨在加强土地用途管制、严守耕地占补平衡的数量型指标规范,往往从方向型指标与量化型指标这两个宏观面向,分别明确规模化耕地保护的整体定位与羁束效应。可进一步围绕宣示性和落实性、控制性和威慑性这两类中观意义表达,依托相应微观层面的指标要素,尝试明晰耕地保护现代化数量型指标体系的多维三级架构,从而为实现数量意义的耕地保护现代化提供必要的渊源性与实施性引导。

基于敏感度分析的非洲粮食生产对耕地资源变化的动态响应

耕地作为粮食生产的载体,耕地资源的变化也影响着粮食生产格局.以非洲有数据的53个国家为研究单元,基于耕地资源指数、重心模型和敏感度模型揭示非洲2000—2020年间耕地资源与粮食生产的时空变化规律,以及粮食生产对耕地资源变化的敏感性.结果发现:1)2000—2020年,非洲耕地面积不断扩大,人均耕地面积稍有下降,耕地资源集中分布在几内亚湾沿岸和非洲的东部地区,而北部与南部非洲地区耕地资源相对稀疏;2)近20年来,非洲粮食产量的分布格局与耕地资源分布基本一致,粮食总产量大幅提高,而受人口持续增加的影响,人均粮食产量基本持平;3)2000—2020年间,非洲粮食生产重心和耕地资源重心均向西北方向移动,粮食生产重心移动仍然受制于耕地面积变化的影响;4)研究期内非洲大部分国家粮食产量对耕地面积变化都表现出低度敏感性,粮食生产对耕地资源数量变化的依赖程度减弱.研究旨在为非洲粮食安全战略规划提供支撑.

Spatiotemporal changes in agricultural land cover in Nepal over the last 100 years

In order to advance land use and land cover change（LUCC） research in Nepal, it is essential to reconstruct both the spatiotemporal distribution of agricultural land cover as well as scenarios that can explain these changes at the national and regional levels. Because of rapid population growth, the status of agricultural land in Nepal has changed markedly over the last 100 years. Historical data is used in this study, encompassing soils, populations, climatic variables, and topography. Data were revised to a series of 30 m grid cells utilized for agricultural land suitability and allocation models and were analyzed using a suite of advanced geographical tools. Our reconstructions for the spatiotemporal distribution of agricultural land in Nepal reveal an increasing trend between 1910 and 2010（from 151.2 × 10^2 km^2 to 438.8 × 10^2 km^2）. This expanded rate of increase in agricultural land has varied between different eco, physiographic, and altitudinal regions of the country, significantly driven by population changes and policies over the period of this investigation. The historical dataset presented in this paper fills an existing gap in studies of agricultural land change and can be applied to other carbon cycle and climate modeling studies, as well as to impact assessments of agricultural land change in Nepal.

天津市抛荒地分布及驱动机理研究

为探明天津市耕地抛荒总体情况和驱动机理,基于MODIS数据,识别并估算2010—2017年天津市耕地抛荒规模,利用核密度分析方法对其空间分布格局进行判定,并基于OLS分析方法系统分析天津市耕地抛荒驱动机理。结果表明:(1)2010—2017年天津市抛荒地规模总体呈减少的态势,年均减少726.26 hm^(2);(2)天津市抛荒地呈现出明显的“阶梯式”分布规律,主要集中在天津市中部和西南部地区,而位于远郊区的蓟县南部、宝坻区北部和滨海新区是抛荒地分布的冷点区;(3)人均收入和总人口密度对耕地抛荒呈现正向影响,海拔、坡度和距河流距离对耕地抛荒呈现负向影响。整体来看,地理资源条件的影响更为显著。

黔南州耕地资源与质量时空变化特征及规律

本文采用ArcGIS空间分析技术,利用土地利用转移矩阵、时间序列分析等方法对黔南州2014—2018年耕地资源与质量的时空变化进行研究,并从州域层面、地理区域层面和县级层面3个空间尺度分析其特征及规律,以期为该区域实施土地开发整治、制定耕地保护与质量管护措施等提供科学依据。结果表明:全州耕地数量在2014—2018年间有增减波动,总体有所增加;近年来通过实施耕地占补平衡、城乡建设用地增减挂钩等,耕地数量达到动态平衡;全州耕地质量总体不高,耕地综合质量等别为11.22;通过实施土地整治、耕地提质改造等工程,近几年耕地质量总体略有提升;西南区域作为全州耕地后备资源集中区,通过开展土地开发与增减挂钩等工程,耕地数量有所增加。