Plant Growth Promoting Rhizobacteria Impact on Typha latifolia and Phragmites australis Growth and Dissolved Oxygen          下载免费PDF全文

Faiza Rehman  Arshid Pervez  Bahadar Nawab Khattak  Rafiq Ahmad 《洁净——土壤、空气、水》2018,46(8)

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Linking physiography and evaporation using the isotopic composition of river water in 16 Canadian boreal catchments   总被引：1，自引：0，他引：1       下载免费PDF全文

Chani Welch  Aaron A. Smith  Tricia A. Stadnyk 《水文研究》2018,32(2):170-184

Highly seasonal boreal catchments are hydrologically complex and generally data poor and, hence, are ripe for investigation using tracer‐aided hydrologic models. The influence of physiography on isotopic metrics was assessed to identify the catchment characteristics dominating evaporative enrichment. A multiyear stable isotope of water dataset was collected at the outlets of 16 boreal catchments in central Canada ranging in area from 12 to 15,282 km². Physiographic characteristics were obtained through raster analysis of freely available land cover images, stream networks, and digital elevation models. Correlation analysis indicated that as the percentage coverage of open water increased, so too did the evaporative effects observed at the catchment outlet. Correlation to wetland metrics indicated that increasing the percentage coverage of wetlands can reduce or increase evaporative effects observed, depending on the isotopic metric used and the corresponding drainage density, catchment slope, and presence of headwater lakes. The slopes of river evaporative‐mixing lines appear to reflect multifaceted relationships, strongest between catchment slope, headwater lakes, and connected wetlands, whereas mean line‐conditioned excess is more directly linked to physiographic variables. Hence, the slopes of river evaporative‐mixing lines and mean line‐conditioned excess are not interchangeable metrics of evaporative enrichment in a catchment. Relationships identified appear to be independent of catchment scale. These results suggest that adequate inclusion of the distribution of open water throughout a catchment, adequate representation of wetland processes, catchment slope, and drainage density are critical characteristics to include in tracer‐aided hydrologic models in boreal environments in order to minimize structural uncertainty.  相似文献   

洞庭湖湿地柳属木本植物与薹草属草本植物群落土壤与水环境特征   总被引：1，自引：0，他引：1  

李有志  李锡泉  张灿明  马丰丰  徐佳娈 《湖泊科学》2015,27(5):887-894

木本与草本是植物存在的两种主要生活型,生态功能差异明显,尤其在植物被周期性洪水淹没的湿地生态系统中.为此,以洞庭湖湿地二门闸、五门闸、藕池河口、白沙大桥4个研究点的原生柳属木本植被与薹草属草本植被为研究对象,通过对枯水期土壤理化性质与汛期水流速度、水环境的对比监测,揭示两者生态防护功能的差异.对土壤粒径组成而言,在二门闸与白沙大桥2个研究点,木本与草本植物群落土壤样本之间无显著差异;而在五门闸与藕池河,与草本植物相比,木本植物导致土壤上层(0~30 cm)与下层(60~90 cm)粉粒含量降低,砂粒含量增加,中层(30~60 cm)黏粒与粉粒含量增加,砂粒含量降低.对土壤化学性质而言,木本植物总体上导致土壤有机质与全氮含量升高,而对全磷与全钾含量无显著影响.与草本植物相比,木本植物能显著减缓水流速度,提高水体氧化还原电位与溶解氧浓度,而对水温与p H值无明显影响.可见,洞庭湖湿地木本与草本植物生活型的差异,是导致二者土壤与水环境特征差别的主要原因,与草本植物相比,木本植物具有更强的生态防护功能.  相似文献   

The Distribution and Enrichment of Trace Metals in the Rainfall‐Driven Supratidal Wetlands of Tianjin,China     

《洁净——土壤、空气、水》2017,45(12)

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Campus Sewage Treatment in Multilayer Horizontal Subsurface Flow Constructed Wetlands: Nitrogen Removal and Microbial Community Distribution     

《洁净——土壤、空气、水》2017,45(11)

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Dust provenance and its role as a potential fertilizing agent for the Okavango Delta,Botswana     

Marc S. Humphries  Claudia R. Benitez-Nelson  Michael Bizimis  Timothy J. Ralph  Zacchary T. Larkin  Terence S. McCarthy 《地球表面变化过程与地形》2020,45(8):1705-1716

Dust plays a globally important role in supplying biologically essential elements to landscapes underlain by nutrient-poor substrates. Here we show that dust may play a significant role in sustaining productivity in the vast wetlands of the Okavango Delta in southern Africa, one of the world's richest biodiversity hotspots. Dust accumulates preferentially on tree-covered islands in the seasonal swamps of the Delta, creating pockets of fine-grained, nutrient-rich material within the semi-arid landscape of the Kalahari Desert. Strontium and neodymium isotopes reveal that this dust likely originates predominantly from the Makgadikgadi salt pans, located 300 km away, and contributes 10–80% of the fine-grained material present in Okavango island soils. Surface material sourced from the Makgadikgadi Pans contains relatively high amounts of bioavailable phosphorus and iron, potentially influencing Okavango Delta biological productivity. We propose that long-term ecosystem productivity and nutrient availability in the Okavango may be strongly mediated by regional dust inputs. Understanding the influence of dust deposition on nutrient loads and biogeochemical cycling is thus critical for predicting the response of the Okavango Delta to future changes in climate. We suggest that dust inputs may play a significant role in the supply of nutrients to other large, global wetland systems located in dryland environments. © 2020 John Wiley & Sons, Ltd  相似文献   

Is There Any Correlation Between Landscape Characteristics and Total Nitrogen in Wetlands Receiving Agricultural Drainages?     

YU Han  WANG Xiaodong  CHU Lijuan  WANG Guodong  SUN Guangzhi  SUN Mingyang  WANG Jingyu  JIANG Ming 《中国地理科学(英文版)》2019,(4):712-724

In the case of increasing fragmentation of wetlands, the study of the relationship between wetland landscape characteristics and total nitrogen(TN) in water is of great significance to reveal the mechanism of wetland water purification. Taking the Naoli River(NR) wetlands in Northeast China as the research object, 10 uniformly distributed sampling sites in the study area were sampled in August 2015 to test the TN concentration and interpret the images of NR wetlands in the same period. Taking the sampling site as the control point, the whole wetlands were divided into 10 regions, and the landscape index of each region was extracted. In order to reveal whether the landscape characteristics are related to the TN concentration in the wetlands water body, the landscape index and the TN concentration in the control point water body were analyzed by correlation analysis, step-by-step elimination analysis and path analysis to reveal whether the landscape characteristics are related to the TN concentration under wetlands receiving agricultural drainages. The results showed that the correlation coefficients between four area indexes or eight shape indexes and TN concentration did not reach a significant correlation level(P > 0.05), indicating that TN removal was not only determined by a single landscape index. The path coefficient of edge density(ED) index is –0.41, indicating that wetland patch connectivity is the primary factor of TN removal, and there is no relationship between the larger patch area and the higher TN removal. The removal of TN in wetlands is restricted by the synergistic effect of landscape area and shape characteristics.  相似文献   

国家重要滨海湿地选划方法初步研究——以盘锦滨海湿地为例          下载免费PDF全文

雷威  丛丕福  刘玉安  卢伟志  廖国祥  刘长安 《海洋开发与管理》2018,35(1):46-51

文章确定了国家重要滨海湿地的认定标准、范围划定原则、命名规则、申报与评定程序,初步建立了适用于我国重要滨海湿地选划的方法体系。以盘锦滨海湿地为例进行案例分析,结果表明:从滨海湿地水鸟角度考虑,在盘锦境内共选划出辽宁盘锦南小河国家重要滨海湿地和辽宁盘锦鸳鸯沟国家重要滨海湿地。在天然滨海湿地持续减少和退化的背景下,文章建立的方法体系将为我国滨海湿地管理与保护工作提供有价值的理论依据。  相似文献   

利津县黄河湿地生态治理浅析          下载免费PDF全文

张志强  吴文超 《山东国土资源》2009,25(2)

测绘文化,是综合实力的体现,是一个文明程度的反映,也是知识形态生产力转化为物质形态生产力的源泉。随着《国务院关于加强测绘工作的意见》的颁布实施,面对新的形势、新的任务、新的机遇、新的挑战,要在激烈的市场竞争中取胜,把单位做大做强,实现单位的跨越发展,就必须培育与经济发展相适应的测绘文化,提高单位在市场环境中的竞争能力、生存能力和发展能力。  相似文献   

辽河三角洲湿地资源景观特征评价及生态旅游开发   总被引：1，自引：0，他引：1  

汤蕾  许东 《地域研究与开发》2007,26(1):72-75

生态旅游概念提出以来,全球生态旅游在理论和实践2个方面都得到了很大发展,成为现在主要的旅游活动形式之一.辽河三角洲是我国七大江河三角洲之一,拥有丰富的湿地资源,非常适合进行生态旅游的开发.文章在分析辽河三角洲湿地资源景观特征的基础上,结合该地区旅游开发存在的问题,对其开展湿地生态旅游的前景作了分析,提出了开展湿地生态旅游的对策.  相似文献