Fishers’ knowledge indicates short-term temporal changes in the amount and composition of catches in the southwestern Atlantic     

《Marine Policy》2016

The scarcity of data on fish catches difficult management of small-scale fisheries in developing countries. This study applies fishers’ knowledge to investigate temporal changes in the amount (biomass) and composition (major ecological categories) of fishing resources exploited by small-scale coastal fisheries in the southeastern Brazilian coast. Four hypotheses were investigated: (1) The amount of fish caught reported by fishers would decrease over time. (2) Older fishers would report higher fish catches than younger fishers. (3) Recent interviews would mention large-sized predators less often. (4) Recent interviews would mention less high valued fishing resources. Interviews with 421 fishers in 36 communities in the southeastern Brazilian coast were analyzed, covering a time span of 14 years, from 1995 to 2009. The hypothesis 1 was confirmed, 3 was partially confirmed, while 2 and 4 were not confirmed. Fishers’ age was unrelated to all variables. The results from fishers’ interviews indicated the temporal trends of: (1) a decrease in the biomass of fish caught; (2) an increase in the occurrence of smaller fish and invertebrates in the catch; (3) an increase of high value fishing resources; and (4) maintenance of large predators. The first two indicators suggest excessive fishing, but the later indicators (3 and 4) suggest that the socioecological system of the southeastern Brazilian coast had not yet undergone major ecological shifts.  相似文献   

The international legal framework for the management of the global oceans social-ecological system     

《Marine Policy》2016

This paper evaluates the international agreements in place for the protection of the environment and the regulation of human activities taking place in world's oceans and seas. 500 multilateral agreements were reviewed against a framework of reference, grounded on the theoretical approaches of Adaptive Management and Transition Management. According to this framework, oceans complex systems management should: (1) consider the global oceans as a Social-Ecological System (SES); (2) aim to achieve or maintain their ecological resilience; and (3) implement iterative, learning-based management strategies, supported by science-based advice to policy and management. The results show that the present international legal framework for the global oceans does not require countries to adopt an adaptive, complex systems approach for global oceans ecological resilience. Instead, this study supports the perspective of a double fragmentation among international agreements. First, global agreements focus on issue-based objectives for determined human activities, ecological components or anthropogenic pressures. Second, regional agreements have a wider scope, but also a varying level of inclusion of ecological resilience considerations. There is the need to foster the inclusion of such an approach into existing and future international agreements and their implementation, including through soft-law, project-based initiatives at global and regional scales.  相似文献   

广东孔江湿地生物多样性保护与生态恢复工程     

赵顺  何明华  彭文鹰 《湿地科学与管理》2016,(1):30-33

针对广东孔江国家湿地公园出现的库周村民生产生活污染、农业面源污染、植被群落单一等问题,开展湿地生物多样性保护与生态恢复工程,为湿地公园后期建设规划提供依据。  相似文献   

广东海丰自然保护区湿地现状及保护对策     

曾向武  周平  高常军 《湿地科学与管理》2016,(1):34-37

广东海丰湿地是中国华南亚热带滨海湿地的典型代表,也是南中国海生态系统的重要组成部分,为多种珍稀、濒危鸟类和候鸟提供重要栖息地和迁徙中转站,具有重要的保护价值。在野外湿地资源调查的基础上,阐述了海丰自然保护区湿地类型与特点、湿地动植物资源、湿地利用现状等生态特征,分析了湿地面临的主要威胁,提出湿地生态系统保护与管理的主要对策和措施。  相似文献   

湿地旅游生态约束机制研究     

叶军  杜旭侠 《湿地科学与管理》2016,(4):56-58

引入湿地旅游资源"资产化管理"和"生态承载能力"两个概念,通过资源资产化管理厘清湿地生态资源所有权和经营权关系,着眼于源头市场化监管,责任约束;通过生态承载能力监控,将湿地生态旅游开发限制在生态良好可控范围之内,从而形成以生态向好带动旅游开发,以旅游开发促进生态投入的良性均衡形态。  相似文献   

Groundwater characteristics and climate and ecological evolution in the Badain Jaran Desert in the southwest Mongolian Plateau     

《China Geology》2021,4(3):421-432

The Badain Jaran Desert is the third largest desert in China, covering an area of 50000 km². It lies in Northwest China, where the arid and rainless natural environment has a great impact on the climate, environment, and human living conditions. Based on the results of 1∶250000 regional hydrogeological surveys and previous researches, this study systematically investigates the circulation characteristics and resource properties of the groundwater as well as the evolution of the climate and ecological environment since the Quaternary in the Badain Jaran Desert by means of geophysical exploration, hydrogeological drilling, hydrogeochemistry, and isotopic tracing. The results are as follows. (1) The groundwater in the Badain Jaran Desert is mainly recharged through the infiltration of local precipitation and has poor renewability. The groundwater recharge in the desert was calculated to be 1.8684×10⁸ m³/a using the water balance method. (2) The Badain Jaran Desert has experienced four humid stages since the Quaternary, namely MIS 13-15, MIS 5, MIS 3, and the Early–Middle Holocene, but the climate in the desert has shown a trend towards aridity overall. The average annual temperature in the Badain Jaran Desert has significantly increased in the past 50 years. In detail, it has increased by about 2.5°C, with a higher rate in the south than in the north. Meanwhile, the precipitation amount has shown high spatial variability and the climate has shown a warming-drying trend in the past 50 years. (3) The lakes in the hinterland of the Badain Jaran Desert continuously shrank during 1973–2015. However, the vegetation communities maintained a highly natural distribution during 2000–2016, with the vegetation cover has increased overall. Accordingly, the Badain Jaran Desert did not show any notable expansion in that period. This study deepens the understanding of groundwater circulation and the climate and ecological evolution in the Badain Jaran Desert. It will provide a scientific basis for the rational exploitation of the groundwater resources and the ecological protection and restoration in the Badain Jaran Desert.© 2021 China Geology Editorial Office.  相似文献   

开封市的城市生态位变化分析   总被引：17，自引：0，他引：17  

丁圣彦  李志恒 《地理学报》2006,61(7):752-762

城市生态位作为生态学重要理论之一,用于分析城市生态不同功能模块间竞争、演化等现象。通过以开封市不同功能模块为研究对象,在各模块污染指数和适宜度指数的基础上,运用生态位理论和方法,探讨改革开放以来,特别是近十年来开封市不同功能模块生态位格局变化规律,并对变化的原因进行了分析。研究结果表明：(1) 1994~2003年开封市自然生态环境系统各模块生态位呈上升趋势的有大气环境模块、城市绿化模块,而呈下降趋势的有水环境模块、声环境模块。(2) 1994~2003年开封市经济系统各模块生态位呈上升趋势的是第三产业模块,呈下降趋势的是第二产业模块,而变化不大的是第一产业模块。(3) 1994~2003年开封市社会系统各模块适宜度生态位呈上升趋势的有社会基础设施模块、社会资源配置模块、社会生产与保障模块,而呈下降趋势的只有人口模块。(4) 国家政策体制的改革是改革开放以来特别是近十年来开封市各功能模块生态位发生变化的最直接和最根本的原因。该研究不但对城市不同功能模块的宏观规划、经济发展和环境保护有具体的指导意义,而且对拓展城市生态学理论、研究复合生态系统的内在作用机制也同样具有重大的理论和现实意义。  相似文献   

珠江口黄茅海底质沉积中介形类的生态类型及其分布特征          下载免费PDF全文

黄毅  吴洁  殷征欣  关瑶  倪锦锋 《海洋开发与管理》2020,37(6):89-94

文章通过对黄茅海底质沉积样品中的介形类生态类型进行研究,探讨其空间分布特征。研究结果显示：研究区内出现的介形类可划分为4种生态类型,总体表现为以近岸广盐型分子占主导地位,优势度极高;浅海多盐 真盐型分子次之;而广海真盐型和淡水 微盐型分子丰度很低。根据黄茅海河口湾的水体条件,可大致将研究区划分为5种亚环境区,各区内的介形类生态类型组成也存在较大差别,表现出不同的空间分布特征。介形类分布受海水盐度控制最大,其次为水动力条件。在水体盐度小、水动力条件强的河流入海口及其影响区域,介形类丰度小,且生态类型单一;而在黄茅海河口湾南部海域,由于海水底层盐度全年在15‰以上,水动力条件适宜,介形类丰度总体较高,生态类型增多。  相似文献   

甘肃酒泉荒漠戈壁灌木群落优势物种生态位特征     

董雪  李永华  张正国  李思瑶  包岩峰  郝玉光  姚斌 《中国沙漠》2020,40(4):138-145

了解物种利用资源和占据生态空间的能力,对维持完善和科学保育荒漠戈壁植物群落的多样性具有重要意义。在综合反映各生态因子作用的群落类型和海拔梯度组合而成的两条资源轴上,测度分析了甘肃酒泉荒漠戈壁灌木群落主要优势种的生态位特征。结果表明：(1)在群落类型和海拔梯度两条资源轴上,红砂（Reaumuria songarica）、泡泡刺（Nitraria sphaerocarpa）和合头草（Sympegma regelii）的重要值和生态位宽度均较大,说明这些物种适应能力强,能够较好地利用环境资源,分布范围大,作为荒漠戈壁灌木群落中的广域种具有重要的生态地位和作用。(2)荒漠戈壁优势物种间的生态位重叠值多数较小,在群落类型和海拔梯度资源轴上生态位重叠值小于0.5的分别占总种对的62.63%和77.89%。生态位宽度大的物种之间一般生态位重叠值较高,物种利用资源能力强且存在竞争关系;然而,生态位宽度较小的物种与其他物种之间的生态位重叠程度较低,不同物种在环境资源的需求上产生互补,可以和谐共存;生态位宽度小的物种之间生态位重叠值仍较高,物种分布呈斑块现象;因此,生态位重叠与生态位宽度之间无显著相关性。(3)荒漠戈壁优势物种间总体表现为不显著的正关联,表明该植被群落结构及其物种之间处于稳定共存的状态。  相似文献   

柴达木盆地盐尘暴及其资源生态环境影响   总被引：1，自引：1，他引：0       下载免费PDF全文

张西营  李雯霞  耿鋆  苗卫良  李永寿  唐启亮  陈亮  袁小龙  郭晓宁  王钰  才仁扎西 《盐湖研究》2020,28(1):11-17

在干旱和半干旱地区,盐尘暴是一种常见的极端气象灾害。柴达木盆地频发的沙尘暴实质上就是盐尘暴。柴达木盆地盐尘暴已经对区域大气、土壤、植被、人类健康乃至全球气候变化都产生了不同程度的影响。由于柴达木盆地盐尘暴中可溶盐成分来源复杂,尽管目前对其形成过程和机制还缺乏深刻理解,但人类的资源开发活动对盐尘暴显然具有促进作用。有必要从系统的角度来考虑柴达木盆地盐尘暴对区域乃至全球的影响,这对于区域生态环境的正确评估和后期恢复治理具有重要意义。  相似文献