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1.
草地是陆地生态系统中最重要、分布最广的生态系统类型之一,对全球碳循环和气候调节有着重要的作用和效应.我国拥有极为丰富的草地资源,是巨大的陆地碳储存库,也是全球碳循环重要组成部分.干湿交替是土壤中普遍发生的自然现象,这种现象的发生可能会加速土壤的碳矿化过程、激增土壤呼吸以及影响微生物的活性和群落结构等.在全球变化日趋显著的背景下,降雨量、降雨强度以及降雨频率的变化将会加速土壤干湿交替进程,进而带来微生物活性、群落结构以及土壤呼吸的变化,并对全球碳循环过程产生重要影响.本文综述了近十年来国内外的相关文献,对干湿交替条件下,土壤释放CO2消耗碳源、土壤呼吸随时间的动态变化趋势以及土壤呼吸与微生物量、微生物活性和微生物群落结构之间的关系进行了分析和总结,以期为更好地理解干湿交替过程中草地生态系统土壤呼吸的微生物学响应机制,更准确地预测和评估未来的全球陆地生态系统的碳收支与气候变化提供一定的理论基础.  相似文献   

2.
赛罕乌拉国家级自然保护区位于内蒙古赤峰市巴林右旗北部,地处大兴安岭山地南段,是内蒙古高原草原向大兴安岭山地森林过渡的地带。自1998年设立省级保护区以来,野生动物资源得到了良好保护,保护区位于我国东北陆地生态系统监测样带的西段部分,对野生动物多样性的保护性监测对于了解生态系统的结构和功能变化具有重要的管理价值。保护区现有大型捕食性猛兽狼(Canis lupus)和猞猁(Lynxlynx)2种(张书理等,2007),近十年来种群数量有所增加,在局部区域造成了一定危害,2007年春季发生了一次较严重的野狼危害家畜事件。2007年保护区境内相邻的4个…  相似文献   

3.
土壤呼吸是植物固定的碳由陆地生态系统进入大气的主要途径之一; 凋落物分解是养分循环的重要环节。陆地植物的90%以上可同菌根真菌形成共生关系, 菌根真菌对于植物获取环境中的养分具有重要的作用。然而, 其对土壤呼吸和凋落物分解的影响却经常在生态系统对环境变化的响应研究中被忽视。本文系统地综述了国内外相关研究进展, 对菌根真菌如何影响土壤呼吸和凋落物分解这两个过程及这种影响如何受到环境变化的制约做了全面的分析, 并对以往研究中存在的问题以及未来的研究方向提出了展望。  相似文献   

4.
<正> 原始节肢动物在由海到陆地的发展过程中,其生活方式发生了很大的变化,它们是如何适应这种环境的变化呢?最重要的环节是如何解决身体水分的保持和精子传递的问题,以保持种族的繁衍。第一个问题的解决是初上陆地的动物还不能离开荫蔽潮湿的生活条件,所以原始的、低等的一些陆栖节肢动物多半生活于潮湿的环境中。第二个问题的解决是产生一种  相似文献   

5.
生态化学计量学理论最早应用在水生生态系统的研究中,但最近20年来在陆地生态系统中也开展了大量的相关研究,特别是关于全球变化背景下陆地植物N/P生态化学计量学方面的研究得到很大的发展,极大地丰富和提升了我们对陆地植物包括生态系统生态过程的认识。就全球变化背景下陆地植物生态化学计量学的研究现状进行了综述,同时以中国科学院华南植物园90周庆为契机,总结我们关于南亚热带森林植物生态化学计量学的研究工作,进而分析当前存在的一些问题并提出今后研究的发展重点,以期促进和推动我园和我国生态化学计量学相关领域的研究。  相似文献   

6.
采用单因子标准指数法确定水期和断面污染类型,用综合污染指数和污染负荷比法判断水期和断面的相对污染程度。根据2005~2009年各断面24项化学指标单因子评价,研究结果表明,上游扶河桥、新城桥断面水质较好,各评价因子5年平均值均未超过地面水二类标准,属Ⅱ类水质;湟水桥、包兰桥、什川桥断面轻度污染,各评价因子5年平均值均未超过地面水三类标准,属Ⅲ类水质。断面污染负荷比依次为:包兰桥23.38%>什川桥21.85%>湟水桥21.18>新城桥18.35%>扶河桥15.18%。  相似文献   

7.
孙航  李志敏 《植物学通报》1990,7(2):29-33,36
在植物的进化中,最重要的一个环节便是由水生到陆生。这一过程的实现,使得今天的生命世界如此形形色色,生机勃勃,丰富多彩。同时,也使地球的环境发生了根本的变化,为陆地生物的生存和进化提供了必要条件。  相似文献   

8.
水质检验的概念和意义自然界的水体按其来源大体可分为三类:①降水:包括雨水和雪水等,该水质的好坏,决定于大气的污染程度,如大气污染严重,空气中各种微生物和杂质含量高,水质就差。②地面水:包括江水、河水、湖水及塘水。地面水由于  相似文献   

9.
《生命世界》2006,(1):45-47
方精云生态学家。北京大学教授。1959年出生于安徽怀宁。1982年毕业于安徽农学院林学系,1989年获日本大阪市立大学生物学博士学位。现任中国生态学会副理事长及国内外多个学术刊物的副主编或编委。建立了我国陆地植被和土壤碳储量的研究方法,系统研究了我国陆地生态系统的碳储量及其变化,较早地开展了碳循环主要过程的野外观测,构建了中国第一个国家尺度的陆地碳循环模式,为我国陆地碳循环的研究奠定了基础;系统研究了我国大尺度的植被动态及时空变化,揭示了我国植被生产力的变化趋势、空间分异及其对气候变化响应的规律;系统开展了我国植被分布与气候关系的定量研究,提出了基于植被气候关系的我国植被带划分的原则和依据,首次采用统一的调查方法,较系统地研究了我国山地植物多样性的分布规律。  相似文献   

10.
陆源人类活动对近海生态系统的影响   总被引:7,自引:0,他引:7  
随着海岸带快速城市化和经济发展,人类活动对近海生态系统的影响日益增加。通过对国内外大量相关文献的分析和与国际专家的研讨,分别从海洋资源开发、海岸带城市化和环境变化等几个方面概述了陆源人类活动对近海生态系统的影响。目前陆源人类活动导致近海生态系统出现的主要问题有:海洋生物资源过度捕捞、海岸带富营养化、海洋酸化、珊瑚礁退化、海洋垃圾、以及海岸带矿产开采等高强度开发活动引发的重金属和持久性有机污染物污染等。这些问题会直接导致海洋生物群落结构变化、影响水质、降低海洋生物多样性,最终影响海洋生态系统服务功能,威胁海洋生态系统健康。这些问题的根源多来自陆地,必须将海洋和陆地作为一个有机整体,整合海陆系统相互作用的科学计划,推进海洋资源和近海生态系统的可持续管理。  相似文献   

11.
The eastern coastal areas of China have high-density population, developed society and economy, and large water pollution emissions. How to reduce water pollution and realize the coordinated development of the economy and environment has become the national focus. Effective environmental policies should consider regional differences in development stage and sustainability performance. Here, we first analyzed the water pollution emissions intensity of the eastern coastal areas of China and the urgency of emissions reduction using 8-year environmental statistics from 2003 to 2010. We characterized development stages of the eastern coastal areas based on the relationships between water pollution emissions intensity and economic development. Further, we built a coordination degree index of economic development and water environment protection as a measure of sustainability. Results show that water pollution emissions intensity decreases as the economy grows from 2003 to 2010. The less-developed regions have a better coordination degree than some more-developed regions, especially those most-developed ones (e.g., Shanghai show more pressures on long-term sustainability than Hebei). The less-developed regions should take advantage of economic growth to invest more advanced environment protection technologies. The more-developed regions need to upgrade its economic structures and municipal infrastructures. Overall, the study provided a comprehensive approach to understand regional difference in development stage and sustainability performance in the eastern coastal region of China as well as the need of different environmental policies to reduce water pollution emissions.  相似文献   

12.
中国的水污染与水短缺问题   总被引:3,自引:0,他引:3  
王菊思 《生态学报》1990,10(1):71-80
1.水污染和水短缺是中国现在面临的最重要的两个环境问题。 2.中国的水污染是从70年代开始趋于严重的,河流、湖泊、海洋和地下水都已受到不同程度的污染。 3.从70年代初期,中国开始注意到环境问题,逐步建立和完善了管理机构和措施,在控制水污染的蔓延和加重方面起了重要作用。 4.乡镇企业造成了许多新的污染源。 5.水短缺及水供需矛盾在中国北方日趋严重,在众多的解决水短缺的措施中,废水再生回用是一种行之有效的途径。  相似文献   

13.
Water scarcity is a widespread problem in many parts of the world. Most previous methods of water scarcity assessment only considered water quantity, and ignored water quality. In addition, the environmental flow requirement (EFR) was commonly not explicitly considered in the assessment. In this study, we developed an approach to assess water scarcity by considering both water quantity and quality, while at the same time explicitly considering EFR. We applied this quantity–quality-EFR (QQE) approach for the Huangqihai River Basin in Inner Mongolia, China. We found that to keep the river ecosystem health at a “good” level (i.e., suitable for swimming, fishing, and aquaculture), 26% of the total blue water resources should be allocated to meet the EFR. When such a “good” level is maintained, the quantity- and quality-based water scarcity indicators were 1.3 and 14.2, respectively; both were above the threshold of 1.0. The QQE water scarcity indicator thus can be expressed as 1.3(26%)|14.2, indicating that the basin was suffering from scarcity problems related to both water quantity and water quality for a given rate of EFR. The current water consumption has resulted in degradation of the basin's river ecosystems, and the EFR cannot be met in 3 months of a year. To reverse this situation, future policies should aim to reduce water use and pollution discharge, meet the EFR for maintaining healthy river ecosystems, and substantially improve pollution treatment.  相似文献   

14.
李丹丹  杨军  宋玉玲  朱桦  于晶  郭水良 《广西植物》2021,41(10):1719-1729
苔藓植物是环境污染的重要指示生物,目前,国内开展的主要是应用苔藓植物进行大气污染的监测,事实上国外已有较多应用苔藓植物进行水体质量监测的工作。该文首先统计分析了国际上应用苔藓植物进行水环境质量监测研究文献,然后从苔藓植物监测的水体污染物类型、监测用苔藓植物种类、苔藓植物材料存活状态对监测效果的影响、影响苔藓植物富集水体重金属元素的环境因素、应用苔藓植物进行水体污染监测的主动与被动方法、样品预处理方法和水体质量监测的应用案例等方面,系统介绍了国际上应用苔藓植物进行水体污染监测的研究和应用概况,提出了今后应用苔藓植物监测水体污染研究值得关注的领域。  相似文献   

15.
As an inherent trait, body-size structure has been used to summarize functional features of a community instead of taxonomic resolutions due to the high redundancy for bioassessment. In this study, the multivariate approaches were used to determine the environmental drivers to the spatial variation in body-size structure based on an annual dataset of biofilm-dwelling protozoa. Samples were monthly collected at four stations within a gradient of pollution in coastal waters of the Yellow Sea, northern China during a 1-year cycle. The second-stage (2STAGE) clustering and ordination analyses demonstrated that the annual patterns were significantly different among four sampling stations. Mantel analysis showed the spatial variations in body-size structures of the protozoa were significantly correlated with the water quality status along the pollution gradient. Best matching analysis revealed that the potential environmental drivers to shape the spatial difference in body-size structure may be pH, chemical oxygen demand (COD) and nutrients (e.g., soluble phosphates, ammonia and nitrates). It is suggested that the multivariate approaches used may determine the environmental drivers to shape the spatial variations in body-size structure of biofilm-dwelling protozoa in marine ecosystems.  相似文献   

16.
The aim of this study was to elucidate how the spatial scale and the set of variables included influence our ability to detect the effects of different types of pollution on the biota. Using variance partitioning analysis, we assessed the individual importance of a set of environmental factors (eutrophication and organic pollution) versus metal level pollution on the community structure of diatom assemblages at different spatial scales. At regional scale, environmental factors did not explain more of the variance compared to the watershed study. The results of the watershed scale field survey indicate that diatom community composition was influenced by low metal concentrations, but this pattern was only observed by the inclusion of biofilm metal concentration data. We recommend the analysis of metal traces in the water phase and the biota (fluvial biofilms) as well as the use of the Diffusive Gradient in Thin films (DGT) technique to characterize low metal level pollution in freshwater systems. Handling editor: Judit Padisák  相似文献   

17.
苔藓植物对环境变化的影响及适应性研究进展   总被引:28,自引:3,他引:25  
苔藓植物由于其结构相对简单,对环境变化的反应较为敏感,是一类良好的生物指示植物,本文综述了水分、光照、温度等方面的环境因子变化对苔藓植物的影响以及苔藓植物对环境污染的响应及适应的最近研究进展,以期促进国内深入开展苔藓植物对环境污染和全球变化的响应、适应及其生态指示作用等研究。  相似文献   

18.
苔藓植物对环境变化的响应及适应性研究进展   总被引:4,自引:0,他引:4  
苔藓植物由于其结构相对简单,对环境变化的反应较为敏感,是一类良好的生物指示植物.本文综述了水分、光照、温度等方面的环境因子变化对苔藓植物的影响以及苔藓植物对环境污染的响应及适应的最近研究进展,以期促进国内深入开展苔藓植物对环境污染和全球变化的响应、适应及其生态指示作用等研究.  相似文献   

19.
Around 92% of the humanity's footprint (WF) relates to the agricultural sector, and a considerable proportion of this is associated with animal farming. In Spain, the swine sector accounts for 11% of agricultural output in economic terms and makes substantial demands on freshwater resources. In this study we estimate the WF of the Spanish pig sector at an average 19.5 billion m3/yr (82% green, 8% blue, 10% grey) over the period 2001–08. During this period the WF increased by 23%, due to growing exports. About half the water needed to produce concentrate feed comes from Spain, with the remaining 50% embodied in imported feedstock products. When comparing the blue and grey WFs of feed production in the source regions with indicators of water scarcity and water pollution, we find that most of the feed produced in Spain, unlike that imported, comes from watersheds where freshwater resources are overexploited. The evaluation of the WF of four different pig production systems shows that pigs raised in extensive systems have the largest WF per tonne of live animal. However, water pollution is a particular problem in industrial systems given the high geographical concentration of animals. The swine sector is one of the largest consumers of natural resources in Spain and should, therefore, be an important focal point in agricultural, environmental and water policies.  相似文献   

20.
两栖动物在水体污染生物监测中作为指示生物的研究概况   总被引:17,自引:0,他引:17  
简单介绍了两栖动物作为指示生物在环境监测中的优越性及其研究历史和现状,同时也概述了我国学者在这方面的研究,总结了污染水体中部分蝌蚪的形态行为特征,并且提出了利用两栖动物的形态和行为模式建立水体污染生物监测仪器的可能性,为生物监测提供了科学依据。  相似文献   

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