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1.
The hydrochemistry of alpine lakes reflects water characteristic and its response to climatic change. Over 300 water samples had been collected from 52 sites of 5 lakes and 7 inflowing rivers in the Yamzhog Yumco Basin, South Tibet, during 2009–2014, basing which the hydrochemical regime and its mechanism were analyzed along with the adoption of hydrological investigations in 1979 and 1984 as well. Results revealed that the waters were hard with weak alkalinity for the Yamzhog Yumco Basin. Most of them were fresh, and the rest were slightly saline. The hydrochemical types of 5 lakes(i.e., Lake Yamzhog Yum Co, Puma Yum Co, Bajiu Co, Kongmu Co, and Chen Co) were SO_4~(2–)–HCO_3~––Mg~(2+)–Na~+, HCO_3~–– SO2–2+4–Mg~(2+)–Ca, SO_4~(2–)–Mg~(2+)–Na~+, SO_4~(2–)–HCO_3~––Ca~(2+), and SO_4~(2–)–Na~+–Mg~(2+)–Ca~(2+), respectively. As for rivers, HCO_3~– and SO_4~(2–) were the major anions, and Ca~(2+) was the dominant cation. Lake Yamzhog Yum Co, the largest lake in the basin, exhibited remarkable spatial variations in hydrochemistry at its surface but irregular changes with depth. The weathering of evaporates and carbonates, together with evaporation and crystallization, were the major mechanisms controlling the hydrochemistry of waters in the Yamzhog Yumco Basin. Global warming also had significant impacts on hydrochemical variations.  相似文献   

2.
从GIS空间关系角度分析,区别于前人通过生态学中土壤质地、生物量、碳存储、氧释放量和水体质量等微观层面评估生态系统服务价值,以地理空间数据为基础,空间分析为核心技术,对浏阳河流域生态系统服务价值的空间异质性进行了研究。首先以1×1 KM格网形式将流域划分,然后将地形、地质灾害点、道路、景点、关心点等人类活动热点分布以及植被覆盖度、植物净初级生产力作为影响因子,然后结合熵值法和层次分析法计算这些因子对生态系统每个服务价值的权重,权重可以反映对生态系统服务价值的影响的程度。受空间异质性影响每个格网都具有不同的空间特征,格网中土地利用类型种类数量不一,存在多种土地类型的格网就构成了微型景观,其复杂的物种组成,稳定的内部结构,提高自身调节,生态系统稳定性也就增强,因此这种景观格局方式使格网内生态服务总价值应该大于各生态系统服务价值代数累加之和。研究发现:9个指标因子中植被覆盖度、植物净初级生产力和道路分布情况对生态服务价值影响最显著,植被覆盖度高、植物净初级生产能力强,道路网密集会提高生态系统服务价值;不同土地类型主要的生态系统服务也不一样:耕地、草地和水体的供给服务、调节服务突出,林地的调节和支持服务突出;在各地类中,耕地和水体生态服务价值受空间异质性影响较大,因为耕地和水体与人类活动密切相关,受自然和人类双重因素影响,而林地和草地由于多位于远离人类的山地和丘陵区,主要受生物和地理环境影响,受空间异质性影响相对较弱。本研究针对生态系统服务价值评估,定量分析每个格网的自然和社会特征因素对生态服务价值估算影响,为精确科学评估生态服务价值提供参考。  相似文献   

3.
森林是陆地生态系统的重要组分,为人类社会提供着多种多样的服务产品。明确不同类型森林生态系统服务的空间特征和驱动机制对优化森林资源管理和提升服务综合效益具有重要意义。基于InVEST模型、CASA模型和GIS技术对赣江流域森林生态系统固碳、蓄积量、水源供给和土壤保持4种服务进行了价值评估和空间制图,并分析了各类自然和社会-经济因子梯度变化与生态系统服务生产之间的联系。结果表明:赣江流域4种森林生态系统服务具有空间异质性。赣江流域周边山地和高丘区域固碳和蓄积量服务较高,林型以阔叶林和竹林为主;水源供给服务较高的区域则为赣江流域东北部,林型以松林和杉木林为主;土壤保持服务空间分布较离散,赣江流域东北部区域略高于西南部区域。生态系统服务是自然过程和人类活动共同作用的结果:随海拔或坡度增加,人类活动干扰减少,森林固碳和蓄积量服务增加,但水源供给和土壤保持服务减小;随区域人均GDP增加或总人口减少,森林固碳和蓄积量服务表现出增加趋势。未来还需进一步评估各类自然和社会-经济因子对不同类型生态系统服务的限制作用和格局影响,以更好地应对区域生态问题。  相似文献   

4.
生态系统利用强度成倍的增加使得生态系统服务与居民需求间的矛盾日益严峻。"一带一路"倡议的提出对老挝生产生活带来了极大的影响,科学评估生态系统服务消耗是探究居民对生态系统影响程度的重要手段。本研究通过收获指数和料肉比等参数对老挝1961–2013年农产品、水果和畜产品消费数据进行转换,分析得到了以下结论:(1)老挝以农田、森林、草地生态系统服务消耗为主,其中农田生态系统服务消耗占比超过80%且有下降趋势,森林生态系统服务消耗占比高于10%且有上升趋势,草地生态系统服务消耗占比不足2%且基本不变,三类生态系统服务消耗量均呈现出先增加、后波动、再增加的变化趋势;(2)老挝生态系统服务消耗在1961–2008年期间形成了"农田生态系统服务消耗一家独大"模式,在2008–2013年期间形成了"农田、森林和草地生态系统服务消耗均衡发展"模式,并且有从前一个模式向后一个模式转变的趋势;(3)老挝生态系统服务消耗模式形成及变化受供给和贸易的影响,老挝在1961–2008年期间以发展农业为主,形成了"农田生态系统服务消耗一家独大"的模式;得益于农、林、畜产品进口种类的不断丰富、贸易额的增长、进口量的增加,2008年后老挝生态系统服务消耗从"农田生态系统服务消耗一家独大"模式转变为"农田、森林和草地生态系统服务消耗均衡发展"模式。本研究为生态系统服务消耗研究提供了实证参考。  相似文献   

5.
生态系统为人类提供了必要的服务,其中大部分是没有市场价格的,因此被认为是\"自然的免费赠品\"而被大量使用。近年来由于快速的工业化和城市化,不断增长的人口已经使人们认识到生态系统服务也是有限的。环境退化是用来描述生态系统服务的损失或损害的常用指标,而移民往往是环境恶化的后果。那么,生态系统服务退化到什么程度才足以导致人们搬迁?本文通过对移民和环境退化相关文献的综述,力求寻求及时监测生态系统退化状况、避免人类承受生态移民痛苦、探求不同环境下人类更好地生存与发展的途径。  相似文献   

6.
近年来,随着中国经济的快速发展,空气污染和土地水污染问题备受关注。然而,中国沿海生态系统的环境污染问题也非常严重,而且并未引起足够的重视。基于中国国家统计局和中国沿海海洋环境监测收集的经济发展和海洋生态系统环境污染数据,分析了中国沿海生态环境污染总量以及渤海、黄海、东海和南海等四大海域的污染情况。经过分析,本文认为,中国沿海不同海域的沿海海洋环境污染存在差异,在海水质量、在超标污染物、入海河流水质和赤潮等沿海海洋环境特征指标方面均存在明显差异。根据研究结果,对改进中国海洋生态环境管理提出了一些政策建议。  相似文献   

7.
In many arid ecosystems,vegetation frequently occurs in high-cover patches interspersed in a matrix of low plant cover.However,theoretical explanations for shrub patch pattern dynamics along climate gradients remain unclear on a large scale.This context aimed to assess the variance of the Reaumuria soongorica patch structure along the precipitation gradient and the factors that affect patch structure formation in the middle and lower Heihe River Basin(HRB).Field investigations on vegetation patterns and heterogeneity in soil properties were conducted during 2014 and 2015.The results showed that patch height,size and plant-to-patch distance were smaller in high precipitation habitats than in low precipitation sites.Climate,soil and vegetation explained 82.5% of the variance in patch structure.Spatially,R.soongorica shifted from a clumped to a random pattern on the landscape towards the MAP gradient,and heterogeneity in the surface soil properties(the ratio of biological soil crust(BSC) to bare gravels(BG)) determined the R.soongorica population distribution pattern in the middle and lower HRB.A conceptual model,which integrated water availability and plant facilitation and competition effects,was revealed that R.soongorica changed from a flexible water use strategy in high precipitation regions to a consistent water use strategy in low precipitation areas.Our study provides a comprehensive quantification of the variance in shrub patch structure along a precipitation gradient and may improve our understanding of vegetation pattern dynamics in the Gobi Desert under future climate change.  相似文献   

8.
揭示喀斯特城市流域土地利用对生态系统服务功能的影响机制,对喀斯特地区的社会经济发展与生态环境保护具有重要意义。本研究以贵州典型喀斯特城市流域—南明河流域为例,基于Arc GIS技术平台揭示了2000–2020年3个时期流域的土地利用时空演变规律,采用In VEST模型对流域不同土地利用类型的生态系统服务功能进行了系统评价。结果表明:(1)流域土地利用以林地、耕地和草地为主,土地利用变化方式主要表现为建设用地的增长,增长了13.07%;(2)流域水源涵养功能显著提升,碳储存功能略微减弱,空间上两者的物质量均呈现东北高、西南低的分布特征;(3)林地对流域水源涵养和碳储量的贡献率均超过57%,林地转为建设用地,耕地转为林地分别是生态系统服务功能减弱和增强的两种土地利用变化形式。本研究可为喀斯特生态脆弱区土地利用结构优化、水土资源开发和生态系统可持续管理提供重要数据支撑与科学参考。  相似文献   

9.
Understanding the controls on seasonal variation of energy partitioning and separation between canopy and soil surface are important for qualifying the vegetation feedback to climate system.Using observed day-to-day variations of energy balance components including net radiation,sensible heat flux,latent heat flux ground heat flux,and meteorological variables combined with an energy-balanced two-source model,energy partitioning were investigated at six sites in Heihe River Basin from 2014 to 2016.Bowen ratio(β) among the six sites exhibited significant seasonal variations while showed smaller inter-annual fluctuations.All ecosystems exhibit a \"U-shaped\" pattern,characterized by smaller value of β in growing season,with a minimum value in July,and fluctuating day to day.During the growing season,average Bowen ratio was the highest for the alpine swamp meadow(0.60 ± 0.30),followed by the desert riparian forest Populus euphratica(0.47 ± 0.72),the alpine desert(0.46 ± 0.10),the Tamarix ramosissima desert riparian shrub ecosystem(0.33 ± 0.57),alpine meadow ecosystem(0.32 ± 0.17),and cropland ecosystem(0.27 ± 0.46).The agreement of Bowen ratio between simulated and observed values demonstrated that the two-source model is a promising tool for energy partitioning and separation between canopy and soil surface.The importance of biophysical control explains the convergence of seasonal and annual patterns of Bowen ratio for all ecosystems,and the changes in Bowen ratio showed divergence among varied ecosystems because of different physiological responses to energy flow pathways between canopy and soil surface.  相似文献   

10.
受气候变化和政策因素的影响,哈萨克斯坦是中亚地区生态退化和草畜矛盾最为突出的国家。研究哈萨克斯坦草地承载状态对认识草地生态系统对气候变化和人类活动的响应尤为重要。本研究基于哈萨克斯坦遥感数据和畜牧业统计数据,以生态系统的供给与消耗为基础,分析哈萨克斯坦草地生态系统与承载状态的格局变化。结果表明:(1)2003–2017年,哈萨克斯坦牲畜养殖数量呈现持续平稳增长的趋势,受冻害影响,在2011年数量有所减少,牲畜养殖结构空间差异不明显。(2)哈萨克斯坦草地供给量波动上升,而畜牧业生产消耗量持续增加,导致草地承载压力不断增加。(3)2003–2017年间,哈萨克斯坦整体的草地承载状态一直呈现富余状态,但草地承载压力指数呈现平稳上升趋势,草地承载压力较大的地区主要位于草地生产力低下的克孜勒奥达尔州、耕地集中的南哈萨克斯坦州和北哈萨克斯坦州,并逐渐向农牧交错区和半荒漠带推进。  相似文献   

11.
农田生态系统服务价值由供给服务价值、调节服务价值、支持服务价值和文化服务价值构成,充分认识农田生态系统服务价值对于农业发展与农田保护有重要指导意义。在构建农田生态系统服务价值评估指标体系基础上,利用市场价值法、碳税法、造林成本法、替代成本法、当量因子法等方法,评估了1997、2002、2007、2012和2017年青岛市农田生态系统服务价值。评估结果表明:1997–2017年青岛市农田生态系统总服务价值由499.74×10~8元增加到681.74×10~8元,单位面积农田生态系统服务价值由6.57×10~4元/公顷增加到9.73×10~4元/公顷。农田的产品供给服务、固碳释氧服务和土壤保持服务是青岛市农田生态系统服务的主要方式,产品供给服务价值、固碳释氧服务价值和土壤保持服务价值占青岛市农田生态系统服务总价值的比重大且呈上升趋势。提出了保护和合理利用农田、因地制宜发展农业生产、提高农业生产效率、加快现代农业园区建设、推进农业供给侧的结构性改革,以及发展生态休闲农业、农业生态旅游等充分利用农田生态系统的间接服务价值,为市民提供最大化福利的青岛市农业发展措施。  相似文献   

12.
湿地是一种独特的自然景观格局,可为人类社会提供多种重要功能和服务。随着我国经济的飞速发展和城市化进程的加剧,内陆湿地面临面积减少、湿地功能减弱、湿地生态环境恶化等一系列问题。因此,对内陆湿地的生态健康状况进行定量评估,对于生态系统的可持续发展至关重要。然而,对湿地生态系统的评估大多是针对单一湿地或流域湿地,很少有研究对国家层面的湿地进行整体健康评估。本文基于土地覆盖数据、气候数据、社会经济数据,利用压力-状态-效应-响应(PSER)模型建立了内陆湿地健康评价指标体系,该模型包含15个评价指标。结合层次分析法对2010–2018年中国内陆湿地的生态系统健康状况进行了评估,结果表明:(1)与行政区划的生态系统健康评价不同,基于网格的湿地生态系统健康评价可以提供更详尽的湿地健康信息。(2)2018年内陆湿地面积比2010年增加了16328km2,2018年湿地生态系统健康指数平均值为3.45,2010年的平均值为3.24。(3)2018年,状况较好、良好、中度和较差的湿地分别占内陆湿地的26.3%、46.4%、26.9%和0.5%。研究结果为湿地生态系统资源的保护和管理提供了实践指导,为土地利用规划和开发提供了可靠的信息。  相似文献   

13.
青藏高原的生态平衡对中国乃至亚洲的生态安全具有极为重要的作用。本文提出和改进了针对高山高原陆地生态系统生态敏感性和脆弱性评估的指标和方法;评价了西藏自治区的冻融侵蚀、土地沙化、水土流失和土地盐渍化的敏感性;并从综合生态敏感性、生态压力和生态弹力三个方面评价了其生态脆弱性。结果显示,西藏陆地生态系统对冻融侵蚀、土地沙化和水土流失问题非常敏感。极度和高度敏感区分别占西藏自治区总面积的9.62%和83.69%。极度和高度脆弱区分别占0.09%和52.61%,主要分布在西藏西部的喜马拉雅和冈底斯山山区,念青唐古拉、唐古拉、可可西里和昆仑山区,及羌塘高原西北部和北部地区。这些结果有助于根据各区域存在的生态问题提出具有针对性的保护方案。  相似文献   

14.
This article describes the lake basins of the Jom-Bolok volcanic region in the East Sayan(the largest manifestation of the Holocene eruptions in Central Asia). The geomorphological position, origins, aspects of the structure and development are reviewed considering its sedimentary filling. The limnic morphogenesis here develops under the conditions of contrasting relief, high energy of neotectonic and exogenous processes. We established that Lake Khara-Nur, formed as a result of lava-damming of the Jom-Bolok river valley, emerged in its present form approximately 6500 years ago. A complex record on the environment and climatic changes, acquired from its sediments, made it possible to determine for the first time in this region the long-term trends in the development of the Middle and Late Holocene mountain geosystems and also the distinction of several paleogeographic stages of the formation of the natural environment. An average geochemical record resolution for the bottom sediments of the lake was made uniquely for the East Siberian lake records and is equal to 35 years, while the palynological record approximates 110 years.  相似文献   

15.
The Babao River Basin is the \"water tower\" of the Heihe River Basin. The combination of vulnerable ecosystems and inhospitable natural environments substantially restricts the existence of humans and the sustainable development of society and environment in the Heihe River Basin. Soil temperature(ST) is a critical soil variable that could affect a series of physical, chemical and biological soil processes, which is the guarantee of water conservation and vegetation growth in this region. To measure the temporal variation and spatial pattern of ST fluctuation in the Babao River Basin, fluctuation of ST at various depths were analyzed with ST data at depths of 4, 10 and 20 cm using classical statistical methods and permutation entropy. The study results show the following: 1) There are variations of ST at different depths, although ST followed an obvious seasonal law. ST at shallower depths is higher than at deeper depths in summer, and vice versa in winter. The difference of ST between different depths is close to zero when ST is near 5℃ in March or –5℃ in September. 2) In spring, ST at the shallower depths becomes higher than at deeper depths as soon as ST is above –5℃; this is reversed in autumn when ST is below 5℃. ST at a soil depth of 4 cm is the first to change, followed by ST at 10 and 20 cm, and the time that ST reaches the same level is delayed for 10–15 days. In chilling and warming seasons, September and February are, respectively, the months when ST at various depths are similar. 3) The average PE values of ST for 17 sites at 4 cm are 0.765 in spring 0.764 in summer 0.735 in autumn 0.723 in winter, which implies the complicated degree of fluctuations of ST. 4) For the variation of ST at different depths, it appears that Max, Ranges, Average and the Standard Deviation of ST decrease by depth increments in soil. Surface soil is more complicated because ST fluctuation at shallower depths is more pronounced and random. The average PE value of ST for 17sites are 0.863 at a depth of 4 cm 0.818 at 10 cm 0.744 at 20 cm. 5) For the variation of ST at different elevations, it appears that Max, Ranges, Average, Standard Deviation and ST fluctuation decrease with increasing elevation at the same soil depth. And with the increase of elevation, the decrease rates of Max, Range, Average, Standard Deviation at 4 cm are –0.89℃/100 m, –0.94℃/100 m, –0.43℃/100 m, and –0.25℃/100 m, respectively. In addition, this correlation decreased with the increase of soil depth. 6) Significant correlation between PE values of ST at depths of 4, 10 and 20 cm can easily be found. This finding implies that temperature can easily be transmitted within soil at depths between 4 and 20 cm. 7) For the variation of ST on shady slope and sunny slope sides, it appears that the PE values of ST at 4, 10 and 20 cm for 8 sites located on shady slope side are 0.868, 0.824 and 0.776, respectively, whereas they are 0.858, 0.810 and 0.716 for 9 sites located on sunny slope side.  相似文献   

16.
Ecosystem services have become one of the core elements of ecosystem management and evaluation. As a key area of ecosystem services and for maintaining national ecological security, ecosystem changes and implementation effect evaluation are important in national key ecological function zones, for promoting the main function zone strategy and for improving the construction of an ecological civilization. This article studies the ecological zone of a tropical rainforest region in the central mountain area of Hainan Island, China. Multi-source satellite data and ground observation statistics are analyzed with geo-statistics method and ecological assessment model. The core analysis of this paper includes ecosystem patterns, quality and services. By means of spatial and temporal scale expansion and multidimensional space-time correlation analysis, the trends and stability characteristics of ecosystem changes are analyzed, and implementation effect evaluation is discussed. The analysis shows a variety of results. The proportion of forest area inside the ecological zone was significantly higher than the average level in Hainan Island. During 1990–2013, settlement gradually increased inside the ecological zone. After implementation of the zone in 2010, human activity intensity increased, with the main land use being urban construction and land reclamation. Water conservation in the ecological function zone was higher than that outside the zone. In general, it increased slightly, but had obvious fluctuations. Soil conservation inside the zone was also better than that outside. However, it demonstrated dramatic fluctuations and relatively poor stability during 1990–2013. The human disturbance index inside the zone was significantly lower than that outside, and had a lower biodiversity threat level. Especially in 2010–2013, the increased range of the human disturbance index inside the zone was significantly less than that outside.  相似文献   

17.
基于生态系统服务供需关系的空间流动研究是连接生态系统服务供给与人类福祉的关键环节。理解生态系统服务产生、流动、使用的全部过程,准确评估生态系统服务供需平衡状况,建立供给与需求之间双向反馈关系,对于科学管理生态系统和保障区域资源可持续发展具有重要意义。综合大量相关文献,本文从生态系统服务供需关系角度出发,归纳了生态系统服务供给、需求的概念和评估方法,阐述了全球变化背景下,土地利用和气候变化两个主要驱动力对生态系统服务时空变化的影响。系统梳理了生态系统服务空间流动方面的研究进展,发现目前研究在文化服务的量化、生态系统服务流动动态研究以及生态系统服务的驱动机制研究方面存在不足,提出明确生态系统服务驱动机制和转移过程、实现生态系统服务不同时空尺度之间的相互转换,是未来将生态系统服务研究更好地用于实践的重要方法。  相似文献   

18.
城市绿地系统作为城市生态系统的一个非常重要的组成部分,在维护城市生态系统稳定、提供生态系统服务以及提高城市环境质量等方面起着积极的作用。本研究以北京市城市区域为例,基于城市绿地空间分布数据和遥感数据,分析了2000-2020年城市绿地景观格局的变化,以及城市绿地生态系统服务及其空间分布的变化,并研究了它们之间的相互作用关系。结果表明:(1)2000-2020年北京城市绿地建设成效较为显著,绿地面积增加了77.41%,主要由耕地和建设用地转变而来。(2)2000-2020年北京城市绿地滞尘量、吸收SO2量、吸收NO2量、降温增湿量、固碳释氧量和暴雨缓排量总体上均呈持续增加的趋势。(3)城市绿地景观变化与绿地生态系统服务之间关系密切,斑块总面积与生态系统服务的相关性最高,除暴雨缓排外,斑块总面积与各项生态系统服务之间的相关系数均高于0.85。研究结果可以为优化北京绿地、更大程度发挥绿地对生态环境的改善作用提供理论指导,为北京市的生态环境建设提供科学依据。  相似文献   

19.
全球气候变化和人类活动已经威胁到流域生态系统。金沙江作为长江上游,研究其生态系统服务功能对维护整个长江流域的生态安全、促进生态可持续性具有重要意义。基于生态系统服务与权衡综合评价(InVEST)模型和修正通用土壤流失方程(RUSLE)模型,对2000–2020年金沙江流域生态系统提供的5种生态系统服务功能:产水量(WY)、生境质量(HQ)、土壤保有量(SR)、食物供应(FS)、碳储量(CS)进行了评价,并分析了它们的时空变化特征,权衡协同关系及其驱动因素。结果表明:(1)2000–2020年间,金沙江流域的各生态系统服务总量除生境质量外都存在不同程度的波动,各生态系统服务在空间分布上基本呈现出东南高西北低的空间格局。(2)CS_SR_HQ和WY_SR_FS之间存在显著的协同关系,WY_CS之间存在显著的权衡关系。(3)CS_SR_HQ的主要驱动因素是净初级生产力(NPP)和土地利用类型(LU),WY_SR_FS的主要驱动因素是年降雨量(PRE)、LU和降雨侵蚀(R),WY_CS的驱动因素在研究期内较多变。  相似文献   

20.
探究草地生态系统碳储量及其驱动因素对实现双碳目标具有重要意义,藏北高原作为我国重要的草地生态系统,其碳储量现状,空间格局以及驱动因素仍存在很大的争议。本文基于藏北高原150个实测样点数据,通过克里金插值和统计方法,评估分析了藏北高原草地生态系统的地上生物量碳密度、地下30 cm深度根系碳密度和土壤碳密度及其空间分布,以及各碳库的主要影响因素。结果表明:藏北高原地上生物量碳密度平均为0.038 kg C m-2,地下生物量碳密度平均为0.284 kg C m-2,土壤碳密度值最大,平均为7.445 kg C m-2。藏北高原草地生态系统总碳储量约为4.08 Pg C,其中植被碳库0.58 Pg C(包括地上生物量和地下生物量),土壤碳库2.58 Pg C (其余分布在裸地中),碳储量分布格局呈现出从东南向西北递减趋势。植被碳库0.58 Pg C(包括地上生物量和地下生物量),约占青藏高原植被碳库的28.29%;土壤碳库2.58 Pg C,约占青藏高原土壤碳库的26.60%。降水、温度和土壤质地均影响生态系统碳储量,其中降水...  相似文献   

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