Eco-environmental quality is a measure of the suitability of the ecological environment for human survival and socioeconomic development.Understanding the spatial-temporal distribution and variation trend of eco-envir...Eco-environmental quality is a measure of the suitability of the ecological environment for human survival and socioeconomic development.Understanding the spatial-temporal distribution and variation trend of eco-environmental quality is essential for environmental protection and ecological balance.The remote sensing ecological index(RSEI)can quickly and objectively quantify eco-environmental quality and has been extensively utilized in regional ecological environment assessment.In this paper,Moderate Resolution Imaging Spectroradiometer(MODIS)images during the growing period(July-September)from 2000 to 2020 were obtained from the Google Earth Engine(GEE)platform to calculate the RSEI in the three northern regions of China(the Three-North region).The Theil-Sen median trend method combined with the Mann-Kendall test was used to analyze the spatial-temporal variation trend of eco-environmental quality,and the Hurst exponent and the Theil-Sen median trend were superimposed to predict the future evolution trend of eco-environmental quality.In addition,ten variables from two categories of natural and anthropogenic factors were analyzed to determine the drivers of the spatial differentiation of eco-environmental quality by the geographical detector.The results showed that from 2000 to 2020,the RSEI in the Three-North region exhibited obvious regional characteristics:the RSEI values in Northwest China were generally between 0.2 and 0.4;the RSEI values in North China gradually increased from north to south,ranging from 0.2 to 0.8;and the RSEI values in Northeast China were mostly above 0.6.The average RSEI value in the Three-North region increased at an average growth rate of 0.0016/a,showing the spatial distribution characteristics of overall improvement and local degradation in eco-environmental quality,of which the areas with improved,basically stable and degraded eco-environmental quality accounted for 65.39%,26.82%and 7.79%of the total study area,respectively.The Hurst exponent of the RSEI ranged from 0.20 to 0.76 and the future trend of eco-environmental quality was generally consistent with the trend over the past 21 years.However,the areas exhibiting an improvement trend in eco-environmental quality mainly had weak persistence,and there was a possibility of degradation in eco-environmental quality without strengthening ecological protection.Average relative humidity,accumulated precipitation and land use type were the dominant factors driving the spatial distribution of eco-environmental quality in the Three-North region,and two-factor interaction also had a greater influence on eco-environmental quality than single factors.The explanatory power of meteorological factors on the spatial distribution of eco-environmental quality was stronger than that of topographic factors.The effect of anthropogenic factors(such as population density and land use type)on eco-environmental quality gradually increased over time.This study can serve as a reference to protect the ecological environment in arid and semi-arid regions.展开更多
The ＂Three-North＂ Shelterbelt is the largest and most distinctive artificial ecological engineering project in China. It has been conducted since November 25, 1978 in the ＂Three-North＂ （i.e., Northeast China, Nor...The ＂Three-North＂ Shelterbelt is the largest and most distinctive artificial ecological engineering project in China. It has been conducted since November 25, 1978 in the ＂Three-North＂ （i.e., Northeast China, North China and Northwest China） regions. In this study, the background and the essential benefits of the ＂Three-North＂ Shelterbelt project are summarized. The basic status and future development of the ＂Three-North＂ Shelterbelt project are also studied. As well, we tried to discuss the problems existing in the current shelterbelt system and the strategies to conduct this ecological project rationally.展开更多
The relationship between the change of forest resources and climatic factor in the, “Three-North” region of China were studied in this paper. The predicting equations of climatic factor (dependent variable) with reg...The relationship between the change of forest resources and climatic factor in the, “Three-North” region of China were studied in this paper. The predicting equations of climatic factor (dependent variable) with regional independent variable (longitude, latitude and altitude) and stand independent variable (forest coverage rate), were developed by extensively using the linear and nonlinear regression methods. With these models, we can calculate the ecological benefit of Shelter-belt forest.展开更多
China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation...China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation, protect agriculture, reduce soil erosion, and control desertification. Although TNP has been ongoing for 45 years, its rationales and effects remain uncertain. Here, we conducted a rangewide assessment of TNP by analyzing data from >10,000 scenes of satellite images and >50,000 field survey plots. The TNP range and definitions of shelterbelts, arboreal forests, and shrublands were changed during the study period, but we used the initial TNP range(4.07 million km2) and the definitions in 1978 for keeping the consistency, comparability, and comprehensiveness. The TNP increased forest coverage from 5.05% in 1978 to 9.69% in 2022, with arboreal forests, shrublands, and shelterbelts increasing by 42.5%, 184.4%,and 53.6%, respectively. However, only 40.1% of the 471,113 km2afforested area was established between 1978 and 2022. The wellestablished shelterbelts improved crop yield by 4.3%-9.5%, but only 10.2% of all the farmlands in TNP regions(TNR) were protected. The total area of soil erosion due to hydraulic forces was reduced by 447,363 km2, with 61% of this reduction attributed to TNP. TNP contributed to the reduction of desertification by 15%, largely due to the low rate of afforestation success and the largely decreased grasslands. The total carbon sequestration from TNP was 1.96 Pg C. Moreover, water storage in TNR showed a decreasing trend, but the contribution rate of TNP was only 7.8%. Our results illustrate that forestry eco-engineering projects are feasible in the management and restoration of arid and semi-arid degraded lands, but attention must be paid to fully considering the ecological carrying capacity of water resources, matching the species to sites, strengthening the post-afforestation management, as well as keeping the balances between composite ecosystems.展开更多
The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has im...The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.展开更多
Water shortage is an important constraint factor in the construction of the Three-North Shelterbelt （TNS）. Here, we analyzed temporal-spatial patterns in water resources and trends in the Three-North region. We eval...Water shortage is an important constraint factor in the construction of the Three-North Shelterbelt （TNS）. Here, we analyzed temporal-spatial patterns in water resources and trends in the Three-North region. We evaluated the water resource carrying capacity （WRCC） of 623 counties in the project area during the fifth phase of the TNS Development Program. Results show that 387 counties are appropriate for forestation, 185 counties can be planted, and 60 counties are inappropriate for forestation because of water resource constraints.展开更多
弄清碳收支变化是促进区域可持续发展的重要方面。研究结合光合能力模型(Photosynthetic Capacity Model,PCM)和呼吸遥感模型(Remote Sensing Model for Ecosystem respiration,Re-RSM)提出了一个完全基于遥感数据的陆地碳收支动态评估...弄清碳收支变化是促进区域可持续发展的重要方面。研究结合光合能力模型(Photosynthetic Capacity Model,PCM)和呼吸遥感模型(Remote Sensing Model for Ecosystem respiration,Re-RSM)提出了一个完全基于遥感数据的陆地碳收支动态评估模型(Remote Sensing Land Carbon Budget Dynamic Assessment Model,RS-CBM),引入中国三北地区(东北、华北和西北地区)7种植被类型(玉米农田、针阔混交林、落叶针叶林、高寒草地、灌丛草甸、荒漠草原和芦苇湿地)的多年碳通量观测数据对RS-CBM模型进行参数化和验证,并应用此模型定量评估了2001—2020年三北地区植被NEE的时空特征与规律。结果表明,RS-CBM模型的模型精度高达0.75,均方根误差为0.07 mol·m^(-2)·d^(-1),RS-CBM模型的NEE模拟值与通量观测值具有较好的一致性,在不同植被类型的生长季旺盛期均出现较明显的碳吸收峰值,但存在不同程度的峰值低估现象。2001—2020年三北地区的NEE变化呈波动上升趋势,年平均值为82.01 g·m^(-2)·a^(-1),年平均增长量为5.843 g·m^(-2)·a^(-1),总体表现为碳汇。三北地区NEE在空间上呈现南高北低,东高西低的空间分异性。综上,RS-CBM模型能较好地模拟出三北地区碳收支变化和空间分布,具有在区域尺度模拟NEE时空变化的潜力。展开更多
基金supported by the National Natural Science Foundation of China(31971578)the Scientific Research Fund of Changsha Science and Technology Bureau(kq2004095)+2 种基金the National Bureau to Combat Desertification,State Forestry Administration of China(101-9899)the Training Fund of Young Professors from Hunan Provincial Education Department(90102-7070220090001)the Postgraduate Scientific Research Innovation Project of Hunan Province(CX20220707)。
文摘Eco-environmental quality is a measure of the suitability of the ecological environment for human survival and socioeconomic development.Understanding the spatial-temporal distribution and variation trend of eco-environmental quality is essential for environmental protection and ecological balance.The remote sensing ecological index(RSEI)can quickly and objectively quantify eco-environmental quality and has been extensively utilized in regional ecological environment assessment.In this paper,Moderate Resolution Imaging Spectroradiometer(MODIS)images during the growing period(July-September)from 2000 to 2020 were obtained from the Google Earth Engine(GEE)platform to calculate the RSEI in the three northern regions of China(the Three-North region).The Theil-Sen median trend method combined with the Mann-Kendall test was used to analyze the spatial-temporal variation trend of eco-environmental quality,and the Hurst exponent and the Theil-Sen median trend were superimposed to predict the future evolution trend of eco-environmental quality.In addition,ten variables from two categories of natural and anthropogenic factors were analyzed to determine the drivers of the spatial differentiation of eco-environmental quality by the geographical detector.The results showed that from 2000 to 2020,the RSEI in the Three-North region exhibited obvious regional characteristics:the RSEI values in Northwest China were generally between 0.2 and 0.4;the RSEI values in North China gradually increased from north to south,ranging from 0.2 to 0.8;and the RSEI values in Northeast China were mostly above 0.6.The average RSEI value in the Three-North region increased at an average growth rate of 0.0016/a,showing the spatial distribution characteristics of overall improvement and local degradation in eco-environmental quality,of which the areas with improved,basically stable and degraded eco-environmental quality accounted for 65.39%,26.82%and 7.79%of the total study area,respectively.The Hurst exponent of the RSEI ranged from 0.20 to 0.76 and the future trend of eco-environmental quality was generally consistent with the trend over the past 21 years.However,the areas exhibiting an improvement trend in eco-environmental quality mainly had weak persistence,and there was a possibility of degradation in eco-environmental quality without strengthening ecological protection.Average relative humidity,accumulated precipitation and land use type were the dominant factors driving the spatial distribution of eco-environmental quality in the Three-North region,and two-factor interaction also had a greater influence on eco-environmental quality than single factors.The explanatory power of meteorological factors on the spatial distribution of eco-environmental quality was stronger than that of topographic factors.The effect of anthropogenic factors(such as population density and land use type)on eco-environmental quality gradually increased over time.This study can serve as a reference to protect the ecological environment in arid and semi-arid regions.
基金support from the National Nature Science Foundation of China(Grant No.30670315)the Global Environmental Research Fund of the Ministry of the Environment of Japan
文摘The ＂Three-North＂ Shelterbelt is the largest and most distinctive artificial ecological engineering project in China. It has been conducted since November 25, 1978 in the ＂Three-North＂ （i.e., Northeast China, North China and Northwest China） regions. In this study, the background and the essential benefits of the ＂Three-North＂ Shelterbelt project are summarized. The basic status and future development of the ＂Three-North＂ Shelterbelt project are also studied. As well, we tried to discuss the problems existing in the current shelterbelt system and the strategies to conduct this ecological project rationally.
文摘The relationship between the change of forest resources and climatic factor in the, “Three-North” region of China were studied in this paper. The predicting equations of climatic factor (dependent variable) with regional independent variable (longitude, latitude and altitude) and stand independent variable (forest coverage rate), were developed by extensively using the linear and nonlinear regression methods. With these models, we can calculate the ecological benefit of Shelter-belt forest.
基金supported by the National Natural Science Foundation of China (32192435, 31025007)CAS Key Research Program of Frontier Sciences (QYZDJ-SSW-DQC027)+1 种基金the Knowledge Innovation Program of Chinese Academy of Sciences (KZCX1-YW-08-02)the Consultation Project supported by Divisions of the Chinese Academy of Sciences (2019-ZW09-A032)。
文摘China's Three-North Protective Forest Program(TNP) is the world's most ambitious afforestation project(ongoing from 1978 to 2050), which aims to increase forest coverage through afforestation and reforestation, protect agriculture, reduce soil erosion, and control desertification. Although TNP has been ongoing for 45 years, its rationales and effects remain uncertain. Here, we conducted a rangewide assessment of TNP by analyzing data from >10,000 scenes of satellite images and >50,000 field survey plots. The TNP range and definitions of shelterbelts, arboreal forests, and shrublands were changed during the study period, but we used the initial TNP range(4.07 million km2) and the definitions in 1978 for keeping the consistency, comparability, and comprehensiveness. The TNP increased forest coverage from 5.05% in 1978 to 9.69% in 2022, with arboreal forests, shrublands, and shelterbelts increasing by 42.5%, 184.4%,and 53.6%, respectively. However, only 40.1% of the 471,113 km2afforested area was established between 1978 and 2022. The wellestablished shelterbelts improved crop yield by 4.3%-9.5%, but only 10.2% of all the farmlands in TNP regions(TNR) were protected. The total area of soil erosion due to hydraulic forces was reduced by 447,363 km2, with 61% of this reduction attributed to TNP. TNP contributed to the reduction of desertification by 15%, largely due to the low rate of afforestation success and the largely decreased grasslands. The total carbon sequestration from TNP was 1.96 Pg C. Moreover, water storage in TNR showed a decreasing trend, but the contribution rate of TNP was only 7.8%. Our results illustrate that forestry eco-engineering projects are feasible in the management and restoration of arid and semi-arid degraded lands, but attention must be paid to fully considering the ecological carrying capacity of water resources, matching the species to sites, strengthening the post-afforestation management, as well as keeping the balances between composite ecosystems.
基金National Natural Science Foundation of China(4117111640961038)
文摘The Shelterbelt Forest System Program in northeast, north and northwest China （the Three-North Shelterbelt Program, TNSP） is the largest ecological reforestation program in the world. TNSP vegetation research has important ecological meaning and profound social and economic signiifcance. Here, spatio-temporal variation in vegetation cover under the TNSP was examined using the NDVI average method, major climatic factors such as temperature and precipitation, and linear regression trend analysis from 1982 to 2006. We found that in the past 25 years, NDVI vegetation in the study area has consistently risen at a rate of 0.007 per decade. Vegetation cover, temperature and precipitation are positively correlated. The area of vegetation associated with precipitation is larger than the area related to temperature;precipitation is the key factor affecting vegetation growth across the TNSP. From 1982 to 2006, regions with improved vegetation cover were found in the central and southern part of the Greater Khingan Mountains, central part of the Lesser Khingan Mountains, northeastern part of the Changbai Mountains, Yanshan Mountians, Western Liaoning Hilly Region, Altai Mountains, Tien Shan Mountains, eastern part of the Qilian Mountains, eastern part of the northwest desert as wel as southern part of the Gul y Region of the Loess Plateau. However, vegetation cover declined on both sides of the Greater Khingan Mountains, western part of the Hulun Buir Plateau, northern part of the Sanjiang Plain, southern part of Horqin Sandy Land, southern part of the northwest desert and northern part of the Gul y Region of the Loess Plateau.
基金the Principal of State Science Key Project (NO. 2007FY110300)the National Natural Science Foundation Item (NO. 41101117)
文摘Water shortage is an important constraint factor in the construction of the Three-North Shelterbelt （TNS）. Here, we analyzed temporal-spatial patterns in water resources and trends in the Three-North region. We evaluated the water resource carrying capacity （WRCC） of 623 counties in the project area during the fifth phase of the TNS Development Program. Results show that 387 counties are appropriate for forestation, 185 counties can be planted, and 60 counties are inappropriate for forestation because of water resource constraints.
