植物物候记录了植物重复生命周期事件的发生时间,是指示全球变化的重要指标。植物物候研究有助于理解生态系统对全球变化的响应,也是模拟陆地生态系统的物质和能量平衡的重要基础。本数据集基于过去70年欧洲物候项目(Pan European Pheno...植物物候记录了植物重复生命周期事件的发生时间,是指示全球变化的重要指标。植物物候研究有助于理解生态系统对全球变化的响应,也是模拟陆地生态系统的物质和能量平衡的重要基础。本数据集基于过去70年欧洲物候项目(Pan European Phenology Project,PEP725)整编的6种代表性木本植物的地面观测物候数据,采用三种考虑春季冷激和积温累积过程的物候模型(Unified、Unichill和时空耦合模型)在大洲尺度上对物候数据进行建模和分析,研制了欧洲地区代表性木本植物格网物候数据集。本数据集包含1951–2021年欧洲地区(34°57′N–72°3′N,25°3′W–40°3′E)6种木本植物的逐年展叶始期和开花始期格网数据,空间分辨率为0.1°,时间分辨率为天。数据集的质量评估表明,欧洲地区各物种展叶始期和开花始期平均误差分别为7.9和7.6天,与其他区域尺度研究中春季物候的模拟误差接近,因此本文格网物候数据具有较高的模拟精度。本数据集旨在更好地表征欧洲地区大洲尺度植物物候的时空格局,为区域其他来源的植物物候数据产品提供有价值的验证参考,亦可为全球变化和陆地生态系统模拟等研究领域提供支撑物候数据。展开更多
1952-2007年中国白蜡树春季物候格网数据(The gridded dataset of spring phenology of Fraxinus chinensis in China from 1952 to 2007)包括1952-2007年共56个逐年文件,该数据是以ARCGIS标准格式存储的白蜡树展叶始期数据,并以经纬度...1952-2007年中国白蜡树春季物候格网数据(The gridded dataset of spring phenology of Fraxinus chinensis in China from 1952 to 2007)包括1952-2007年共56个逐年文件,该数据是以ARCGIS标准格式存储的白蜡树展叶始期数据,并以经纬度1度为单位的格网数据。它是中国区域物候学研究的产出成果,是表征中国近50年物候时空变化及格局的基础数据。在该数据基础上的研究论文被IPCC第五次评估报告所引用。展开更多
Land use and land cover in China have changed greatly during the past 300 a, indicated by the rapid abrupt decrease of forest land area and the rapid increase of cropland area, which can affect terrestrial carbon cycl...Land use and land cover in China have changed greatly during the past 300 a, indicated by the rapid abrupt decrease of forest land area and the rapid increase of cropland area, which can affect terrestrial carbon cycle greatly. The first-hand materials are used to analyze main characteristics for land use and land cover changes in China during the study period. The following conclusions can be drawn from this study. The cropland area in China kept increasing from 60.78×106 hm2 in 1661 to 96.09×106 hm2 in 1998. Correspondingly, the forest land area decreased from 248.13×106 hm2 in 1700 to 109.01×106 hm2 in 1949. Affected by such changes, the terrestrial ecosystem carbon storage decreased in the mean time. Car-bon lost from land use and land cover changes mainly consist of the loss from vegetation biomass and soil. In the past 300 a, about 3.70 PgC was lost from vegetation biomass, and emissions from soil ranged from 0.80 to 5.84 PgC. The moderate evaluation of soil losses was 2.48 PgC. The total loss from vegetation and soil was between 4.50 and 9.54 PgC. The moderate and optimum evaluation was 6.18 PgC. Such carbon losses distribution varied spatially from region to region. Carbon lost more significantly in Northeast China and Southwest China than in other regions, because losses of forest land in these two regions were far greater than in the other regions during the past 300 a. And losses of carbon in the other regions were also definite, such as Inner Mongolia, the western part of South China, the Xinjiang Uygur Autonomous Region, and the Qinghai-Tibet Plateau. But the carbon lost very little from the traditional agricultural regions in China, such as North China and East China. Studies on the relationship between land use and land cover change and carbon cycle in China show that the land use activities, especially those related to agriculture and forest management, began to affect terrestrial carbon storage positively in recent years.展开更多
We selected widely distributed and well observed plant species Fraxinus chinensis to study the formation mechanism of geographical distribution of the plant phenophase changes and revealed their spatiotemporal dynamic...We selected widely distributed and well observed plant species Fraxinus chinensis to study the formation mechanism of geographical distribution of the plant phenophase changes and revealed their spatiotemporal dynamics in China. Based on the first leaf date (FLD) data at 12 sites derived from Chinese Phenological Observation Network (CPON) and related meteorological data, we developed and validated the process-based model of FLD for Fraxinus chinensis. After reconstructing data series of FLD for Fraxinus chinensis over the study area from 1952 to 2007, we analyzed different spatiotemporal patterns of phenophase changes of this species. The results suggested that the process-based model was able to simulate the FLD accurately for Fraxinus chinensis on large spatial and temporal scales, because of the consideration of different budding rate responded to the air temperatures during the dormancy and the quiescence in accordance with the physiological mechanism of plants. The geographical distribution of the spring phenology in temperate regions was determined by the spatial pattern of daily average air temperature. The changes of FLD for Fraxinus chinensis revealed significant phenological advances in most areas. However, it showed delayed trends in a few sites. The overall average change trend was 1.1 days/decade. This result was consistent with the advanced trend in other regions of the North Hemisphere. The changes of FLD showed a noticeable regional variation with clearer advance in the north than in the south. The FLD in northern China showed an average advance as high as 2.0 days/decade (P<0.01). And the advance in northeastern and northwestern China was respectively 1.5 and 1.4 days/decade (P<0.01). Furthermore, eastern and central regions showed a minor trend, which was 1.0 days/decade (P<0.05). The smallest and non-significant advance appeared in southwestern and southern China.展开更多
Land use/cover change is an important parameter in the climate and ecological simulations. Although they had been widely used in the community, SAGE dataset and HYDE dataset, the two representative global historical l...Land use/cover change is an important parameter in the climate and ecological simulations. Although they had been widely used in the community, SAGE dataset and HYDE dataset, the two representative global historical land use datasets, were little assessed about their accuracies in regional scale. Here, we carried out some assessments for the traditional cultivated region of China （TCRC） over last 300 years, by comparing SAGE2010 and HYDE （v3.1） with Chinese Historical Cropland Dataset （CHCD）. The comparisons were performed at three spatial scales： entire study area, provincial area and 60 km by 60 km grid cell. The results show that （1） the cropland area from SAGE2010 was much more than that from CHCD moreover, the growth at a rate of 0.51% from 1700 to 1950 and -0.34% after 1950 were also inconsistent with that from CHCD. （2） HYDE dataset （v3.1） was closer to CHCD dataset than SAGE dataset on entire study area. However, the large biases could be detected at provincial scale and 60 km by 60 km grid cell scale. The percent of grid cells having biases greater than 70% （〈-70% or 〉70%） and 90% （〈-90% or 〉90%） accounted for 56%-63% and 40%-45% of the total grid cells respectively while those having biases range from -10% to 10% and from -30% to 30% account for only 5%-6% and 17% of the total grid cells respectively. （3） Using local historical archives to reconstruct historical dataset with high accuracy would be a valu- able way to improve the accuracy of climate and ecological simulation.展开更多
With the global warming, crop phenological shifts in responses to climate change have become a hot research topic. Based on the long-term observed agro-meteorological phenological data （1981-2009） and meteorological...With the global warming, crop phenological shifts in responses to climate change have become a hot research topic. Based on the long-term observed agro-meteorological phenological data （1981-2009） and meteorological data, we quantitatively analyzed temporal and spatial shifts in maize phenology and their sensitivities to key climate factors change using climate tendency rate and sensitivity analysis methods. Results indicated that the sowing date was significantly delayed and the delay tendency rate was 9.0 d·10a^-1. But the stages from emergence to maturity occurred earlier （0.1 d·10a^-1〈θ〈1.7 d·10a^-1, θ is the change slope of maize phenology）. The length of vegetative period （VPL） （from emergence to tasseling） was shortened by 0.9 d·10a^-1, while the length of generative period （GPL） （from tasseling to maturity） was lengthened by 1.7 d·10a^-1. The growing season length （GSL） （from emergence to maturity） was lengthened by 0.4 d·10a^-1. Correlation analysis indicated that maize phenology was significantly correlated with average temperature, precipitation, sunshine duration and growing degree days （GDD） （p〈0.01）. Average temperature had significant negative correlation relationship, while precipitation, sunshine duration and growing degree days had significant positive correlations with maize phenology. Sensitivity analysis indicated that maize phenology showed different responses to variations in key climate factors, especially at different sites. The conclusions of this research could provide scientific supports for agricultural adaptation to climate change to address the global food security issue.展开更多
文摘植物物候记录了植物重复生命周期事件的发生时间,是指示全球变化的重要指标。植物物候研究有助于理解生态系统对全球变化的响应,也是模拟陆地生态系统的物质和能量平衡的重要基础。本数据集基于过去70年欧洲物候项目(Pan European Phenology Project,PEP725)整编的6种代表性木本植物的地面观测物候数据,采用三种考虑春季冷激和积温累积过程的物候模型(Unified、Unichill和时空耦合模型)在大洲尺度上对物候数据进行建模和分析,研制了欧洲地区代表性木本植物格网物候数据集。本数据集包含1951–2021年欧洲地区(34°57′N–72°3′N,25°3′W–40°3′E)6种木本植物的逐年展叶始期和开花始期格网数据,空间分辨率为0.1°,时间分辨率为天。数据集的质量评估表明,欧洲地区各物种展叶始期和开花始期平均误差分别为7.9和7.6天,与其他区域尺度研究中春季物候的模拟误差接近,因此本文格网物候数据具有较高的模拟精度。本数据集旨在更好地表征欧洲地区大洲尺度植物物候的时空格局,为区域其他来源的植物物候数据产品提供有价值的验证参考,亦可为全球变化和陆地生态系统模拟等研究领域提供支撑物候数据。
文摘1952-2007年中国白蜡树春季物候格网数据(The gridded dataset of spring phenology of Fraxinus chinensis in China from 1952 to 2007)包括1952-2007年共56个逐年文件,该数据是以ARCGIS标准格式存储的白蜡树展叶始期数据,并以经纬度1度为单位的格网数据。它是中国区域物候学研究的产出成果,是表征中国近50年物候时空变化及格局的基础数据。在该数据基础上的研究论文被IPCC第五次评估报告所引用。
基金Chinese Academy of Sciences (Grant No. KZCX2-YW-315-4)Key Project of National Scientific and Technological Support Plan (Grant No. 2007BAC03A11)the National Natural Science Foundation of China (Grant Nos. 40471047 and 40571007)
文摘Land use and land cover in China have changed greatly during the past 300 a, indicated by the rapid abrupt decrease of forest land area and the rapid increase of cropland area, which can affect terrestrial carbon cycle greatly. The first-hand materials are used to analyze main characteristics for land use and land cover changes in China during the study period. The following conclusions can be drawn from this study. The cropland area in China kept increasing from 60.78×106 hm2 in 1661 to 96.09×106 hm2 in 1998. Correspondingly, the forest land area decreased from 248.13×106 hm2 in 1700 to 109.01×106 hm2 in 1949. Affected by such changes, the terrestrial ecosystem carbon storage decreased in the mean time. Car-bon lost from land use and land cover changes mainly consist of the loss from vegetation biomass and soil. In the past 300 a, about 3.70 PgC was lost from vegetation biomass, and emissions from soil ranged from 0.80 to 5.84 PgC. The moderate evaluation of soil losses was 2.48 PgC. The total loss from vegetation and soil was between 4.50 and 9.54 PgC. The moderate and optimum evaluation was 6.18 PgC. Such carbon losses distribution varied spatially from region to region. Carbon lost more significantly in Northeast China and Southwest China than in other regions, because losses of forest land in these two regions were far greater than in the other regions during the past 300 a. And losses of carbon in the other regions were also definite, such as Inner Mongolia, the western part of South China, the Xinjiang Uygur Autonomous Region, and the Qinghai-Tibet Plateau. But the carbon lost very little from the traditional agricultural regions in China, such as North China and East China. Studies on the relationship between land use and land cover change and carbon cycle in China show that the land use activities, especially those related to agriculture and forest management, began to affect terrestrial carbon storage positively in recent years.
基金supported by National Natural Science Foundation of China (Grant Nos. 41030101 and 40871033)Strategic Leader in Science and Technology Project of Chinese Academy of Sciences(Grant No. XDA05090301)
文摘We selected widely distributed and well observed plant species Fraxinus chinensis to study the formation mechanism of geographical distribution of the plant phenophase changes and revealed their spatiotemporal dynamics in China. Based on the first leaf date (FLD) data at 12 sites derived from Chinese Phenological Observation Network (CPON) and related meteorological data, we developed and validated the process-based model of FLD for Fraxinus chinensis. After reconstructing data series of FLD for Fraxinus chinensis over the study area from 1952 to 2007, we analyzed different spatiotemporal patterns of phenophase changes of this species. The results suggested that the process-based model was able to simulate the FLD accurately for Fraxinus chinensis on large spatial and temporal scales, because of the consideration of different budding rate responded to the air temperatures during the dormancy and the quiescence in accordance with the physiological mechanism of plants. The geographical distribution of the spring phenology in temperate regions was determined by the spatial pattern of daily average air temperature. The changes of FLD for Fraxinus chinensis revealed significant phenological advances in most areas. However, it showed delayed trends in a few sites. The overall average change trend was 1.1 days/decade. This result was consistent with the advanced trend in other regions of the North Hemisphere. The changes of FLD showed a noticeable regional variation with clearer advance in the north than in the south. The FLD in northern China showed an average advance as high as 2.0 days/decade (P<0.01). And the advance in northeastern and northwestern China was respectively 1.5 and 1.4 days/decade (P<0.01). Furthermore, eastern and central regions showed a minor trend, which was 1.0 days/decade (P<0.05). The smallest and non-significant advance appeared in southwestern and southern China.
基金China Global Change Research Program, No.2010CB950901 National Natural Science Foundation of China, No.41271227 No.41001122
文摘Land use/cover change is an important parameter in the climate and ecological simulations. Although they had been widely used in the community, SAGE dataset and HYDE dataset, the two representative global historical land use datasets, were little assessed about their accuracies in regional scale. Here, we carried out some assessments for the traditional cultivated region of China （TCRC） over last 300 years, by comparing SAGE2010 and HYDE （v3.1） with Chinese Historical Cropland Dataset （CHCD）. The comparisons were performed at three spatial scales： entire study area, provincial area and 60 km by 60 km grid cell. The results show that （1） the cropland area from SAGE2010 was much more than that from CHCD moreover, the growth at a rate of 0.51% from 1700 to 1950 and -0.34% after 1950 were also inconsistent with that from CHCD. （2） HYDE dataset （v3.1） was closer to CHCD dataset than SAGE dataset on entire study area. However, the large biases could be detected at provincial scale and 60 km by 60 km grid cell scale. The percent of grid cells having biases greater than 70% （〈-70% or 〉70%） and 90% （〈-90% or 〉90%） accounted for 56%-63% and 40%-45% of the total grid cells respectively while those having biases range from -10% to 10% and from -30% to 30% account for only 5%-6% and 17% of the total grid cells respectively. （3） Using local historical archives to reconstruct historical dataset with high accuracy would be a valu- able way to improve the accuracy of climate and ecological simulation.
基金National Natural Science Foundation of China, No.41671037, No.41301091 The National Key Research and Development Program of China, No.2016YFA0602402 The Youth Innovation Promotion Association of CAS, No.2016049
文摘With the global warming, crop phenological shifts in responses to climate change have become a hot research topic. Based on the long-term observed agro-meteorological phenological data （1981-2009） and meteorological data, we quantitatively analyzed temporal and spatial shifts in maize phenology and their sensitivities to key climate factors change using climate tendency rate and sensitivity analysis methods. Results indicated that the sowing date was significantly delayed and the delay tendency rate was 9.0 d·10a^-1. But the stages from emergence to maturity occurred earlier （0.1 d·10a^-1〈θ〈1.7 d·10a^-1, θ is the change slope of maize phenology）. The length of vegetative period （VPL） （from emergence to tasseling） was shortened by 0.9 d·10a^-1, while the length of generative period （GPL） （from tasseling to maturity） was lengthened by 1.7 d·10a^-1. The growing season length （GSL） （from emergence to maturity） was lengthened by 0.4 d·10a^-1. Correlation analysis indicated that maize phenology was significantly correlated with average temperature, precipitation, sunshine duration and growing degree days （GDD） （p〈0.01）. Average temperature had significant negative correlation relationship, while precipitation, sunshine duration and growing degree days had significant positive correlations with maize phenology. Sensitivity analysis indicated that maize phenology showed different responses to variations in key climate factors, especially at different sites. The conclusions of this research could provide scientific supports for agricultural adaptation to climate change to address the global food security issue.
