Changes in the Ecological Characteristics of Key Biodiversity Areas in the BRI Region     

WANG Boyu  YAN Huimin  FENG Zhiming  YANG Yanzhao 《资源与生态学报(英文版)》2022,13(2):328-337

Key Biodiversity Areas (KBAs) are ecological conservation priorities proposed by IUCN and widely recognized by most countries. Evaluating the changes in the ecological characteristics in KBAs is important for biodiversity conservation and the construction of Protected Areas (PAs). There are various ecosystem types in the Belt and Road Initiative (BRI) region, which has an extremely high value of biodiversity conservation, and the KBAs should be the prime targets of ecological protection efforts. Using the data of land cover, NDVI and Nighttime Light (NTL), we analyzed the ecological conditions of the KBAs in the BRI region, and their temporal and spatial variations, from the perspectives of vegetation coverage and human activities. The conclusions are: (1) There is generally no significant difference in the land cover of the KBAs, among which forest, wilderness and grassland are the main types; (2) The NDVI of the KBAs showed an increase, indicating that the vegetation was gradually improving, while a few KBAs presenting vegetation degradation were mainly distributed in the Indochina Peninsula, Qinghai-Tibet Plateau and Central and Western Asia; and (3) The NTL in the KBAs was very low, indicating that the human pressure on the natural ecosystems was limited, and only a few KBAs distributed in Central and Eastern Europe, India, and the Indochina Peninsula have high human activity intensity which also showed an increase. This study emphasizes that we should make full use of the biome succession law, and limit the interference of human activities on natural ecosystems for ecological protection of the KBAs, so as to continuously make new breakthroughs in the construction of Protected Areas (PA) in the BRI region.  相似文献   

基于FY3/MERSI数据的辽宁省植被指数重建及时空变化分析     

冯锐  纪瑞鹏  武晋雯  于文颖  刘丹  陈妮娜  王莹  张玉书 《气象与环境学报》2022,38(1):65-73

为建立中国风云三系列气象卫星长时间序列归一化植被指数数据集,选用滤波和函数拟合方法,针对林地、湿地、水稻、玉米、大豆、城市和水体7类地物开展数据重建效果定量分析,确定最佳数据重建方法,并在辽宁省开展时空变化分析。结果表明：非对称高斯函数拟合法（Asymmetric Gaussians,AG）、Savitzky-Golay滤波法（SG）、双Logistic函数拟合法（Double Logistic,DL）和时间序列谐波分析法（Harmonic Analysis of Time Series,HANTS）四种方法均表现出相对较好的去噪能力。SG方法对噪声比较敏感,HANTS方法在低值区受噪声影响大。AG和DL方法平滑效果较好,DL方法的峰值更接近于原始峰值。在高植被覆盖区和季节性作物区,SG方法相关系数最高（>0.93）、均方根误差最低（< 0.1）;在城市和水体低植被指数区,HANTS方法相关系数最高,为0.87,但四种方法的均方根误差均在0.06左右,差别不大。综合考虑曲线和定量分析结果,选取SG方法进行辽宁省植被指数数据集数据重建。辽宁省植被指数数值高低的空间分布与下垫面植被类型相符合,东部山区林地植被指数最高,达到0.75以上。2009-2020年,辽宁省NDVI年均值存在波动,不同地物植被指数变化存在差别,水体和城市植被指数变化相对较小,旱田作物（玉米、大豆）的植被指数受干旱年的影响植被指数变化稍大。辽宁省主要粮食作物植被指数年内均呈单峰分布,与一年一熟型吻合,均在8月上旬达到最大值。  相似文献   

Changes in Global Vegetation Distribution and Carbon Fluxes in Response to Global Warming: Simulated Results from IAP-DGVM in CAS-ESM2     

Xiaofei GAO  Jiawen ZHU  Xiaodong ZENG  Minghua ZHANG  Yongjiu DAI  Duoying JI  He ZHANG 《大气科学进展》2022,39(8):1285-1298

Terrestrial ecosystems are an important part of Earth systems, and they are undergoing remarkable changes in response to global warming. This study investigates the response of the terrestrial vegetation distribution and carbon fluxes to global warming by using the new dynamic global vegetation model in the second version of the Chinese Academy of Sciences (CAS) Earth System Model (CAS-ESM2). We conducted two sets of simulations, a present-day simulation and a future simulation, which were forced by the present-day climate during 1981–2000 and the future climate during 2081–2100, respectively, as derived from RCP8.5 outputs in CMIP5. CO₂ concentration is kept constant in all simulations to isolate CO₂-fertilization effects. The results show an overall increase in vegetation coverage in response to global warming, which is the net result of the greening in the mid-high latitudes and the browning in the tropics. The results also show an enhancement in carbon fluxes in response to global warming, including gross primary productivity, net primary productivity, and autotrophic respiration. We found that the changes in vegetation coverage were significantly correlated with changes in surface air temperature, reflecting the dominant role of temperature, while the changes in carbon fluxes were caused by the combined effects of leaf area index, temperature, and precipitation. This study applies the CAS-ESM2 to investigate the response of terrestrial ecosystems to climate warming. Even though the interpretation of the results is limited by isolating CO₂-fertilization effects, this application is still beneficial for adding to our understanding of vegetation processes and to further improve upon model parameterizations.  相似文献   

区域景观格局变化及生态修复——以北京门头沟区为例     

吴国玺  喻铮铮  刘良云 《地理研究》2011,30(7):1227-1236

以1979年和2005年的LandsatTM影像为数据源,在对其进行几何订正、大气和地形辐射校正的基础上,采用归一化植被指数和改进的像元二分模型,对北京市门头沟区的植被覆盖进行了动态遥感监测,结果表明该区植被覆盖总体上呈下降趋势。在此基础上结合研究区边界矢量文件和DEM数据,利用GIS技术和生态景观指标分析方法,定量分...  相似文献   

应用“北京一号”遥感数据计算官厅水库库滨带植被覆盖度   总被引：7，自引：0，他引：7  

杨胜天  李茜  刘昌明  智泓  王雪蕾 《地理研究》2006,25(4):570-578

“北京一号”卫星是拥有多方面技术优势的一颗对地观测小卫星。本文在运用“北京一号”、SPOT5、QuickBird遥感图像对官厅水库库滨带植被覆盖度进行综合监测的基础上,对三种不同分辨率的遥感图像进行基于统计的尺度转换,并应用尺度转换的结果修正了“北京一号”图像提取的植被覆盖度。经检验,运用SPOT5和QuickBird图像对“北京一号”图像进行像元分解,将统计结果与“北京一号”图像的提取信息建立统计模型,应用该统计模型可以有效地提高“北京一号”图像提取植被覆盖度的精度。对湿生植被进行样方调查,结果证明运用像元分解和统计模型的方法使“北京一号”提取植被覆盖度的精度较运用植被指数转换模型的计算精度提高了22.7%。应用该方法可以更有效地运用“北京一号”遥感数据进行连续、大面积的植被监测。  相似文献   

基于植被指数和土地表面温度的干旱监测模型   总被引：79，自引：4，他引：79  

王鹏新  WAN Zheng-ming  龚健雅  李小文  王锦地 《地球科学进展》2003,18(4):527-533

干旱是一种周期性发生的自然现象,其发生过程中有关参数如地表覆盖度、温度和土壤表层含水量等可以通过遥感的途径进行定量反演,而这些参数客观地反映了地表的综合特征。综述了运用遥感反演产品---土地表面温度和归一化植被指数在干旱监测中的应用前景和进展,分析了距平植被指数、条件植被指数、条件温度指数和归一化温度指数等干旱监测方法的优缺点,在前人研究的基础上,提出了条件植被温度指数的干旱监测模型,探讨了其应用前景。  相似文献   

Fractions and Bioavailability of Soil Inorganic Phosphorus in the Loess Plateau of China under Different Vegetations   总被引：1，自引：0，他引：1  

WEI Xiaorong  SHAO Mingan  SHAO Hongbo  GAO Jianlun  XU Gang 《《地质学报》英文版》2011,85(1):263-270

Plants play an important role in soil phosphorus nutrition. However, the effect of plants on phosphorus nutrition in soils of the Loess Plateau of China is not well understood. This study was conducted to reveal the relationships between plants and phosphorus’ fractions and availability in the Loess Plateau of China. Twenty-two plant communities were surveyed and soil samples under different plant canopies were collected for the determination of soil properties and inorganic phosphorus fractionation. The results showed that Leguminosae and Lilaceae reduced pH and increased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies, while Labiatae and Rosaceae increased pH and decreased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies. The contents of Ca2P, Ca8P, Al-P and Fe-P were highly related with soil Olsen phosphorus. They were all higher in soils under Leguminosae and Lilaceae and lower in soils under Labiatae and Rosaceae. The results of this study indicate that Leguminosae and Lilaceae improved phosphorus nutrition in soils, yet Labiatae and Rosaceae impeded the improvement of phosphorus nutrition in soils under their canopies, which will be of more help to instruct vegetation restoration in the region and provide information for soil development.  相似文献   

农田蒸散双层模型及其在干旱遥感监测中的应用   总被引：60，自引：4，他引：60  

隋洪智  田国良  李付琴 《遥感学报》1997,1(3):220-224

该文建立了在部分植被条件下估算农田蒸散的双层模型，利用此模型和ＮＯＡＡ－ＡＶＨＲＲ数据对黄淮海平原春季旱情进行了评估，并做出了干旱及蒸散分布图。对双层模型和单层模型的估算结果进行了比较，结果表明在部分植被条件下双层模型估算的精度要高。  相似文献   

中国植被类型区大气增温趋势及其不对称性研究   总被引：1，自引：0，他引：1  

张慧  靳英华  神祥金  李光棣  周道玮 《地理科学》2018,38(2):272-283

利用1962~2011年中国各植被类型区的452个站点的气温资料,分析了各植被类型区的年平均温度和极端温度随时间的变化趋势。结果表明：① 过去50 a间,中国各植被类型区年平均气温、年平均最高温、年平均最低温都显著升高,并且最低温增温速度快于最高温增温速度,呈温差减小的不对称增温趋势;同时,寒冷地区增温速度高于温暖地区的增温速度,其中寒温带森林的增温幅度超过亚热带森林的2倍。近30 a间,寒温带森林区和温带森林区增温速度减缓,其他各植被类型区增温速度加快,呈现出热带、亚热带地区增温速度高于温带、寒温带地区的空间特点;② 最高温增温速度在变快,最低温增加速度在变慢,多个植被类型区的最高温增温速度高于最低温增温速度,呈现出一种新的不对称增温趋势,即最高温与最低温间的温差在加大;③ 过去50 a和近30 a间,生长季和非生长季的温度变化多样,并分别对年平均温度产生了不同的影响,而生长季和非生长季温度的不同变化分别决定于其最高温和最低温的多样变化。  相似文献   

Spectral discrimination of giant reed (Arundo donax L.): A seasonal study in riparian areas     

《ISPRS Journal of Photogrammetry and Remote Sensing》2013

The giant reed (Arundo donax L.) is amongst the one hundred worst invasive alien species of the world, and it is responsible for biodiversity loss and failure of ecosystem functions in riparian habitats. In this work, field spectroradiometry was used to assess the spectral separability of the giant reed from the adjacent vegetation and from the common reed, a native similar species.The study was conducted at different phenological periods and also for the giant reed stands regenerated after mechanical cutting (giant reed_RAC). A hierarchical procedure using Kruskal–Wallis test followed by Classification and Regression Trees (CART) was used to select the minimum number of optimal bands that discriminate the giant reed from the adjacent vegetation. A new approach was used to identify sets of wavelengths – wavezones – that maximize the spectral separability beyond the minimum number of optimal bands. Jeffries Matusita and Bhattacharya distance were used to evaluate the spectral separability using the minimum optimal bands and in three simulated satellite images, namely Landsat, IKONOS and SPOT.Giant reed was spectrally separable from the adjacent vegetation, both at the vegetative and the senescent period, exception made to the common reed at the vegetative period. The red edge region was repeatedly selected, although the visible region was also important to separate the giant reed from the herbaceous vegetation and the mid infrared region to the discrimination from the woody vegetation. The highest separability was obtained for the giant reed_RAC stands, due to its highly homogeneous, dense and dark-green stands. Results are discussed by relating the phenological, morphological and structural features of the giant reed stands and the adjacent vegetation with their optical traits. Weaknesses and strengths of the giant reed spectral discrimination are highlighted and implications of imagery selection for mapping purposes are argued based on present results.  相似文献