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Effects of riparian vegetation patterns on the distribution and potential loss of soil nutrients： a case study of the Wenyu River in Beijing

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Frontiers of Environmental Science & Engineering 2015年第2期9卷 279-287页

作者： Erhui GUO Liding CHEN Ranhao SUN Zhaoming WANG State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

A riparian ecosystem is an ecological transition zone between a river channel and terrestrial ecosystems. riparian ecosystems play a vital role in maintaining stream health and bank stabilization. The types of riparian vegetation have changed greatly because of human activities along the Wenyu River. This study examines the impact of riparian vegetation patterns on water pollution due to soil nutrient loss. Four riparian vegetation patterns from the river channel to the upland were chosen as the focus of this study： grassland, cropland, grassland- cropland, and grassland-manrnade lawn. The different distributions of soil nutrients along vegetation patterns and the potential risk of nutrient loss were observed and compared. The results showed that riparian cropland has the lowest value of total nitrogen （TN）, total phosphorus （TP）, available nitrogen （AN）, available phosphorus （AP）, and organic matter （OM）, but it has the highest soil bulk density （BD）. The distributions of soil TN, TP, AN, AP, and OM exhibited a declining trend from the upland toward the river channel for riparian cropland, whereas a different trend was observed for the riparian grassland. The vegetation patterns of grassland-cropland and grassland- manmade lawn show that the grassland in the lower slope has more nutrients and OM but lower soil BD than the cropland or manmade lawn in the upper slope. So, the lower-slope grassland may intercept and infiltrate surface runoff from the upland. The lower-slope grassland has higher levels of soil TN, TP, AN, and AP, and thus it may become a new source of nutrient loss. Our results suggest that the management of the riparian vegetation should be improved, particularly in densely populated areas, to control soil erosion and river pollution.

关键词： riparian vegetation pattems soil nutrientdistribution nutrient loss management

Responses of distribution pattern of desert riparian forests to hydrologic process in Ejina oasis

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Science China Earth Sciences 2004年第Z1期47卷 21-31页

作者： ZHAO Wenzhi, CHANG Xueli & HE ZhibinLinze Inland River Basin Comprehensive Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Yantai Normal University, Yantai 264005, China Linze Inland River Basin Comprehensive Research Station Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou China Yantai Normal University Yantai China

By using the theories and methods of landscape ecology and the technology of GIS and RS, a study has been carried out on the responses of distribution pattern of desert riparian forest to hydrologic process on the basis of the hydrologic data from 1990 to 2000 and the TM image of 2001 year. The results showed that: (1) there appears an even distribution pattern for the relative forest area in oasis, however, the degenerated forest diaplays an increasing tendency from west to east; (2) the desert riparian forest in Ejina is in completely degenerated process at the patch scale; (3) the number of patch is influenced not only by hydrologic process,but also by agricultural activity such as cultivation. The severe deterioration of the degraded vegetation in whole oasis initiates from lower reaches, and gradually impels to upstream; the fragmentation of landscape in the terminal site is more obvious, which is influenced by river shape and decreasing flux of water. It is found that the influence of surface hydrologic process to the ground hydrologic process of desert riparian forest in Ejina oasis is little for the recent ten years. The relative area of the degenerated forest increased with increasing ground water depth in the direction of parallel to river channel. On the contrary, in the direction perpendicular to river channel, there is a decreasing tendency for the average patch area of the forest and the degenerated forest with increasing ground water depth.

关键词： Ejina oasis, desert riparian forests, vegetation pattern, hydrologic process.

The effects of indigenous prescribed fire on riparian vegetation in central California

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Ecological Processes 2013年第1期2卷 245-253页

作者： Don L Hankins Department of Geography and Planning California State University-ChicoChicoCAUSA

Introduction:Fire has a long history,but little documented role,as a process in riparian ecosystems.For millennia California Indians have applied fire to riparian ecosystems for a variety of purposes,but the effects of such fires on riparian vegetation are poorly known outside of traditional knowledge structures of indigenous communities.Methods:This study involved the seasonal application of fire based on traditional ecological knowledge versus alternate burn methods to assess fire effects on riparian vegetation in central California.Results:While the annual variation amongst treatments was not significant,the results of this study suggest that fall burns support higher overall richness and native species richness;spring burns yield a decrease in overall richness,but an increase in native species richness;and summer burns contribute to an initial decline in overall and native species richness.The evenness indices of treatments increase most with spring and summer burning.Conclusion:These findings are key to understanding the seasonal role of fire in managing native species in areas prone to non-native or other invasive species.This research demonstrates the application of traditional ecological knowledge to facilitate an understanding of how prescribed fire could aid in the management and conservation of riparian ecosystems.

关键词： riparian California Indian Fire Indigenous Traditional ecological knowledge

How changes of groundwater level affect the desert riparian forest ecosystem in the Ejina Oasis,Northwest China

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Research in Cold and Arid Regions 2019年第1期11卷 62-80页

作者： HaiYang Xi JingTian Zhang Qi Feng Lu Zhang JianHua Si TengFei Yu Key Laboratory of Ecohydrology of Inland River Basin Institute of Eco-Environment and Resources Chinese Academy of Sciences Alashan Desert Eco-hydrology Experimental Research Station University of Chinese Academy of Sciences CSIRO Land and Water Flagship

Groundwater is a key factor controlling the growth of vegetation in desert riparian systems. It is important to recognise how groundwater changes affect the riparian forest ecosystem. This information will not only help us to understand the ecological and hydrological process of the riparian forest but also provide support for ecological recovery of riparian forests and water-resources management of arid inland river basins. This study aims to estimate the suitability of the Water Vegetation Energy and Solute Modelling(WAVES) model to simulate the Ejina Desert riparian forest ecosystem changes,China, to assess effects of groundwater-depth change on the canopy leaf area index(LAI) and water budgets, and to ascertain the suitable groundwater depth for preserving the stability and structure of desert riparian forest. Results demonstrated that the WAVES model can simulate changes to ecological and hydrological processes. The annual mean water consumption of a Tamarix chinensis riparian forest was less than that of a Populus euphratica riparian forest, and the canopy LAI of the desert riparian forest should increase as groundwater depth decreases. Groundwater changes could significantly influence water budgets for T. chinensis and P. euphratica riparian forests and show the positive and negative effects on vegetation growth and water budgets of riparian forests. Maintaining the annual mean groundwater depth at around 1.7-2.7 m is critical for healthy riparian forest growth. This study highlights the importance of considering groundwater-change impacts on desert riparian vegetation and water-balance applications in ecological restoration and efficient water-resource management in the Heihe River Basin.

关键词： groundwater changes desert riparian forest Ejina Oasis WAVES leaf area index(LAI) water budgets

Geomorphic predictors of riparian vegetation in small mountain watersheds

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Journal of Plant Ecology 2015年第6期8卷 593-604页

作者： Blake M.Engelhardt Jeanne C.Chambers Peter J.Weisberg Department of Natural Resources and Environmental Science University of NevadaMS 1861664 Virginia StreetRenoNV 89557USA USDA Forest Service Rocky Mountain Research Station920 Valley RoadRenoNV 89512USA

Aims Hydrogeomorphic processes operating at watershed,process zone and site scales influence the distribution of riparian vegeta-tion.However,most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site scales.We quantified the relative importance of watershed,process zone and site geomorphic characteristics for predicting riparian plant community types and plant species abundances in four small mountain watersheds in central Nevada,u.Methods We mapped riparian vegetation types and identified process zones(based on dominant geomorphic process and valley fill material)within the watersheds.We sampled sites in each combination of veg-etation type and process zone(n=184 sites)and collected data on watershed scale factors,valley and stream geomorphic characteristics and on plant cover of each geomorphic surface.Plant community types were defined by cluster and indicator species analyses of plant cover data,and related to geomorphic variables using ordination analysis(nonmetric multidimensional scaling).linear mixed effects models were used to predict abundances of indicator species.Important Findings Variables describing position in the watershed(elevation,contrib-uting area)that are related to gradients of temperature,moisture and stream discharge were of primary importance in predicting plant community types.Variables describing local geomorphic setting(valley width,stream gradient,channel sediments,geomor-phic surface height)were of secondary importance,but accurately described the geomorphic setting of indicator species.The process zone classification did not include position in the watershed or channel characteristics and only predicted plant community types with unique geomorphic settings.In small mountain watersheds,predicting riparian vegetation distribution requires explicit consid-eration of scale and geomorphic context within and among water-sheds in addition to site variables.

关键词： great basin multiscale plant community analysis process zone riparian

Spatiotemporal variations of CO_(2) fluxes in a Cynodon-dominated riparian zone of the Three Gorges Reservoir(TGR),China

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Journal of Plant Ecology 2018年第6期11卷 877-886页

作者： Wenli Zhang Jiquan Chen Ju Liu Fangqing Chen Quanfa Zhang Zutao Ouyang Changliang Shao Yi Fan Wennian Xu College of Biological and Pharmaceutical Sciences China Three Gorges UniversityYichangHubei 443002China Hubei International Scientific and Technological Cooperation Center of Ecological Conservation and Management in Three Gorges Area China Three Gorges UniversityYichang443002China Center for Global Change and Earth Observations/Geography Environment and Spatial SciencesMichigan State UniversityEast LansingMI 48823USA Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical Gardenthe Chinese Academy of SciencesWuhan 430074China

Aims riparian ecosystems play an important role in overall ecosystem function,including the global carbon cycle of terrestrial ecosystems,at both landscape and global scales.Yet few studies have reported in situ measurements of CO_(2) in riparian areas where flooding is a unique disturbance to carbon cycling.Methods At multiple locations across riparian zones(RZ)with different water submergences in Xiangxi Bay(XXB),we studied seasonal variations of CO_(2) exchange between this Cynodon-dominated community and the atmosphere for 2 years by using static chambers.Important Findings We found that the seasonal changes in CO_(2) fluxes were apparent and dependent on the biophysical environment.In the beginning of spring,low gross primary productivity(GPP)in lightly flooded zones(LFZ)resulted in a positive net ecosystem exchange(NEE),indicating a net CO_(2) source.With the increase in temperature,more species and vegetation abundance appeared,and the increased GPP turned the LFZ from a net CO_(2) source into a sink.This transi-tion seemed predominantly controlled by the physiological growth of vegetation.The mean NEEs,REs and the light-use efficiency(α)of the vegetation at HFZ and MFZ were significantly higher than those at LFZ and UFZ.Yet the coefficients of variation(CV)of NEE and RE at MFZ and HFZ were lower than those at LFZ and UFZ.Submergence promoted the emission and uptake of CO_(2) to the atmosphere.Elongated submergence reduced the number of spe-cies and lowered the spatial variability of the RZ,further lowering the variation of the CO_(2) exchange.

关键词： CO_(2)exchange riparian submergence spatial variability Q_(10) TGD

Pilot Study on the Effects of Partially Restored riparian Plant Communities on Habitat Quality and Biodiversity along First-Order Tributaries of the Lower St. Johns River

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Journal of Water Resource and Protection 2010年第9期2卷 771-782页

作者： Anthony M. Rossi Daniel C. Moon Dale Casamatta Kelly Smith Christopher Bentzien Jason McGregor Alyson Norwich Emilie Perkerson Ralph Perkerson Joanna Savinon Keith Stokes Dean Doebberfuhl 不详

The St. Johns River is one of the premiere waterways in the southeastern United States, but it is increasingly affected by anthropogenic disturbances and influences such as excessive loading of nutrients. In the current pilot project, small native plant communities (“garden sites”) were established along sections of riparian corridors of five first-order tributaries in residential-commercial areas that drain into the lower St. Johns River in north Florida. In addition, four “non-garden” (control) tributaries were monitored for comparison. Garden sites included five species native to the area;20 plants of each species on both banks (200 total plants). These sites were used to assess the ability of partially restored riparian areas to ameliorate nutrient loading and water quality and determine their impact on local biodiversity in disturbed suburban drainage systems. Partially restored sites showed a significant reduction in both NO3- and P concentrations in both soil and water samples compared to control sites. For instance, soil NO3- levels were reduced by 14% in garden sites, while water samples were 30% lower. Moreover, both plant species richness and Shannon diversity (H’) were significantly higher at partially restored sites, 33 and 19% respectively, compared to control streams after two years. Garden sites also had significantly higher terrestrial and invertebrate diversity than non-restored tributaries. Intermittent patches of partially restored habitat along suburban riparian corridors may provide a practical cost-effective technique for improving ecosystem function, water quality and increasing biodiversity along these frequently disturbed lotic habitats. Trends detected in the current study may have general implications for riparian restoration and reduction of nutrient loading in these small tributaries and, ultimately, effect water quality of the lower St. Johns River basin.

关键词： riparian Restoration Biodiversity Soil and Water Quality

Phosphorus Release from Sediments in a riparian <i>Phragmites australis</i>Community at the Estuary of the Chikugogawa River, Western Japan

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American Journal of Plant Sciences 2012年第7期3卷 962-970页

作者： Akira Haraguchi Faculty of Environmental Engineering The University of Kitakyushu Hibikino 1-1 Wakamatsu Kitakyushu 808-0135 Japan.

In order to determine the contribution of aquatic macrophyte communities on nutrition to sustain the high primary productivity of an estuary aquatic community, we analyzed the process of phosphorus release from sediments in aquatic macrophyte community in the estuary of the Chikugogawa River, South-Western Japan. Vertical profile of PD3-4 concentration and redox potential (Eh) of pore water in sediments were investigated within and outside the Phragmites australis community. Sediment horizon lower than 23 cm layer from the surface showed anaerobic (Eh australis community, whereas sediment was constantly oxic (Eh > 0 mV) up to 50 cm depth outside the P. australis community without organic matter accumulation. Non-vegetated sediment with organic matter accumulation showed anoxic profile as vegetated site. PD3-4 concentration in anaerobic parts of sediment showed higher than oxic parts, and higher PD3-4 concentration in sediment pore water corresponded to sulfur deposition in sediment. Sulfate ion supplied from the sea water is reduced under the anoxic condition and S2- reacts with water-insoluble phosphorus salts e.g. Fe3(PO4)2 or AlPO4 and Fe2S3 or Al2S3 precipitates. Thus PD3-4 was mobilized and released under anoxic sediments. P. australis supply organic litter to sediment and the sediment within the P. australis community showed anoxic after aerobic decomposition of organic substances in sediment. Incubation of sediments under N2 atmosphere accumulated PD3-4 in the medium corresponding to low Eh (3-4 was released under anaerobic condition. Estuary P. australis community has function for supplying PD3-4 to river water.

关键词： Phosphorus Mobilization Productivity Redox Potential riparian Plant Community Salt Marsh

Power as Resource-Power as Discourse: An Overview Evaluation of the Key-Factors of “Wind Farms” and “riparian Rights” as Sources of Power

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Engineering（科研） 2011年第1期3卷 63-72页

作者： Grigorios L. Kyriakopoulos 不详

Nowadays, the concept of power can illuminate the nature of contestation. Indeed, it is apparent that discourse coalitions exist both within the wind sector and the riparian corridors management. In the present study, a theoretical framework for policy power analysis is presented, while a balanced European and national energy policies representation reveals the positive and negative impacts, towards which both the above two power sources may be attributed. The “power” holistic approach is mainly determined in a wider social-economic, political, and environmental framework. This multidimensional and holistic approach is considered invaluable for humans/consumers, in order them to determine their capacities, priorities and perspectives for viable use of power within the above complex-structured framework. Finally, the study adopts a balanced reassessment of the existing policies, offering tentative proposals for reducing conflicts.

关键词： Resources Discourses riparian Rights Wind Power Socioeconomic Environment