WorldWideScience

Sample records for riparian buffer systems

  1. RESEARCH NEEDS IN RIPARIAN BUFFER RESTORATION

    Science.gov (United States)

    Riparian buffer restorations are used as management tools to produce favorable water quality impacts; moreover, the basis for riparian buffers as an instrument of water quality restoration rests on a relatively firm foundation. However, the extent to which buffers can restore rip...

  2. Phosphorus retention in riparian buffers: review of their efficiency.

    Science.gov (United States)

    Hoffmann, Carl Christian; Kjaergaard, Charlotte; Uusi-Kämppä, Jaana; Hansen, Hans Christian Bruun; Kronvang, Brian

    2009-01-01

    Ground water and surface water interactions are of fundamental importance for the biogeochemical processes governing phosphorus (P) dynamics in riparian buffers. The four most important conceptual hydrological pathways for P losses from and P retention in riparian buffers are reviewed in this paper: (i) The diffuse flow path with ground water flow through the riparian aquifer, (ii) the overland flow path across the riparian buffer with water coming from adjacent agricultural fields, (iii) irrigation of the riparian buffer with tile drainage water from agricultural fields where disconnected tile drains irrigate the riparian buffer, and (iv) inundation of the riparian buffer (floodplain) with river water during short or longer periods. We have examined how the different flow paths in the riparian buffer influence P retention mechanisms theoretically and from empirical evidence. The different hydrological flow paths determine where and how water-borne P compounds meet and interact with iron and aluminum oxides or other minerals in the geochemical cycling of P in the complex and dynamic environment that constitutes a riparian buffer. The main physical process in the riparian buffer-sedimentation-is active along several flow paths and may account for P retention rates of up to 128 kg P ha(-1) yr(-1), while plant uptake may temporarily immobilize up to 15 kg P ha(-1) yr(-1). Retention of dissolved P in riparian buffers is not as pronounced as retention of particulate P and is often below 0.5 kg P ha(-1) yr(-1). Several studies show significant release of dissolved P (i.e., up to 8 kg P ha(-1) yr(-1)).

  3. Buffer Strips for Riparian Zone Management

    National Research Council Canada - National Science Library

    1991-01-01

    This study provides a review of technical literature concerning the width of riparian buffer strips needed to protect water quality and maintain other important values provided by riparian ecosystem...

  4. Where should buffers go? modeling riparian habitat connectivity in northeast Kansas

    Science.gov (United States)

    Gary Bentrup; Todd Kellerman

    2004-01-01

    Through many funding programs, riparian buffers are being created on agricultural lands to address significant water quality problems. Society and landowners are demanding many other environmental and social services (e.g., wildlife habitat and income diversification) from this practice. Resource planners therefore need to design riparian buffer systems in the right...

  5. Spatial Characterization of Riparian Buffer Effects on Sediment Loads from Watershed Systems

    Science.gov (United States)

    Understanding all watershed systems and their interactions is a complex, but critical, undertaking when developing practices designed to reduce topsoil loss and chemical/nutrient transport from agricultural fields. The presence of riparian buffer vegetation in agricultural lands...

  6. META-ANALYSIS OF NITROGEN REMOVAL IN RIPARIAN BUFFERS

    Science.gov (United States)

    Riparian buffer zones, the vegetated region adjacent to streams and wetlands, are thought to be effective at intercepting and controlling nitrogen loads entering water bodies. Riparian buffer width may be positively related to nitrogen removal effectiveness by influencing nitrog...

  7. Riparian buffer zones as pesticide filters of no-till crops.

    Science.gov (United States)

    Aguiar, Terencio R; Bortolozo, F R; Hansel, F A; Rasera, K; Ferreira, M T

    2015-07-01

    Several studies have pointed to the potential benefits of riparian vegetation as buffer zones for agricultural and industrial pollutants harmful to aquatic ecosystems. However, other studies have called into question its use as an ecological filter, questioning the widths and conditions for which they are effective as a filter. In this work, we have investigated the buffering capacity of the riparian one to retain pesticides in the water-saturated zone, on 27 sites composed by riparian buffer zones with different vegetation structure (woody, shrubs, or grass vegetation) and width (12, 36, and 60 m). Five pesticides were analyzed. The effectiveness of the filtering was largely influenced by the width and vegetation type of the buffer zone. In general, decreasing pesticide removal followed in this order wood > shrubs > grass. The 60 m woody buffer zone was the most effective in the removal of all the pesticides. Only atrazine was detected in this case (0.3 μg L(-1)). Furthermore, a linear correlation (R (2) > 0.97) was observed in their removal for all compounds and buffer zones studied. Thus, preserving the woody vegetation in the riparian zone is important for watershed management and groundwater quality in the no-tillage system in temperate climate.

  8. Stream water responses to timber harvest: Riparian buffer width effectiveness

    Science.gov (United States)

    Barton D. Clinton

    2011-01-01

    Vegetated riparian buffers are critical for protecting aquatic and terrestrial processes and habitats in southern Appalachian ecosystems. In this case study, we examined the effect of riparian buffer width on stream water quality following upland forest management activities in four headwater catchments. Three riparian buffer widths were delineated prior to cutting; 0m...

  9. Concentrated flow paths in riparian buffer zones of southern Illinois

    Science.gov (United States)

    R.C. Pankau; J.E. Schoonover; K.W.J. Willard; P.J. Edwards

    2012-01-01

    Riparian buffers in agricultural landscapes should be designed to trap pollutants in overland flow by slowing, filtering, and infiltrating surface runoff entering the buffer via sheet flow. However, observational evidence suggests that concentrated flow is prevalent from agricultural fields. Over time sediment can accumulate in riparian buffers forming berms that...

  10. Riparian ecosystems and buffers - multiscale structure, function, and management: introduction

    Science.gov (United States)

    Kathleen A. Dwire; Richard R. Lowrance

    2006-01-01

    Given the importance of issues related to improved understanding and management of riparian ecosystems and buffers, the American Water Resources Association (AWRA) sponsored a Summer Specialty Conference in June 2004 at Olympic Valley, California, entitled 'Riparian Ecosystems and Buffers: Multiscale Structure, Function, and Management.' The primary objective...

  11. Effects of riparian buffers on hydrology of northern seasonal ponds

    Science.gov (United States)

    Randall K. Kolka; Brian J. Palik; Daniel P. Tersteeg; James C. Bell

    2011-01-01

    Although seasonal ponds are common in northern, glaciated, forested landscapes, forest management guidelines are generally lacking for these systems. The objective of this study was to determine the effect of riparian buffer type on seasonal pond hydrology following harvest of the adjacent upland forest. A replicated block design consisting of four buffer treatments...

  12. Quantifying Phosphorus Retnention in Soils of Riparian Buffers Influenced by Different Land Use Practices

    Science.gov (United States)

    Lancellotti, B.; Ross, D. S.; Adair, C.; Schroth, A. W.; Perdrial, J. N.

    2017-12-01

    Excess phosphorus (P) loading to freshwater systems can lead to eutrophication, resulting in algal blooms and subsequent fish kills. Lake Champlain, located between Vermont, New York, and Quebec, has historically exhibited negative effects of eutrophication due to P overloading from non-point sources. To reduce P inputs to the Lake, the Vermont Agency of Natural Resources requires and provides guidelines for the management of riparian buffers, which help protect adjacent water bodies from nutrient and sediment runoff. To better understand how phosphorous retention in riparian buffers is influenced by soil wetness and adjacent land use, we explored differences in P content between riparian buffers located in forested and agricultural watersheds. Within each land use type, we focused on two paired riparian buffers with contrasting soil moisture levels (one wet transect and one dry transect). At each of the four sites, soil pits were dug along a transect perpendicular to the streambank and were placed strategically to capture convergent and divergent landscape positions. Soil samples were collected from each horizon within 0-30cm. In each of these samples, we measured orthophosphate, degree of phosphorus saturation (DPS), and trace elements. We investigated the relationship between DPS and aluminum (Al) and iron (Fe) concentrations to determine how much of the variability in DPS was explained by Al and Fe concentrations, and compared these relationships between the four riparian buffer sites. We also assessed how these relationships varied with depth in the soil profile. The results of these analyses allow us to identify the characteristics of riparian buffers that promote the most effective P sequestration, which is beneficial to the effective management of riparian areas within the Lake Champlain basin.

  13. Surface runoff water quality in a managed three zone riparian buffer.

    Science.gov (United States)

    Lowrance, Richard; Sheridan, Joseph M

    2005-01-01

    Managed riparian forest buffers are an important conservation practice but there are little data on the water quality effects of buffer management. We measured surface runoff volumes and nutrient concentrations and loads in a riparian buffer system consisting of (moving down slope from the field) a grass strip, a managed forest, and an unmanaged forest. The managed forest consisted of sections of clear-cut, thinned, and mature forest. The mature forest had significantly lower flow-weighted concentrations of nitrate, ammonium, total Kjeldahl N (TKN), sediment TKN, total N (nitrate + TKN), dissolved molybdate reactive P (DMRP), total P, and chloride. The average buffer represented the conditions along a stream reach with a buffer system in different stages of growth. Compared with the field output, flow-weighted concentrations of nitrate, ammonium, DMRP, and total P decreased significantly within the buffer and flow-weighted concentrations of TKN, total N, and chloride increased significantly within the buffer. All loads decreased significantly from the field to the middle of the buffer, but most loads increased from the middle of the buffer to the sampling point nearest the stream because surface runoff volume increased near the stream. The largest percentage reduction of the incoming nutrient load (at least 65% for all nutrient forms) took place in the grass buffer zone because of the large decrease (68%) in flow. The average buffer reduced loadings for all nutrient species, from 27% for TKN to 63% for sediment P. The managed forest and grass buffer combined was an effective buffer system.

  14. Breeding Bird Community Continues to Colonize Riparian Buffers Ten Years after Harvest.

    Directory of Open Access Journals (Sweden)

    Scott F Pearson

    Full Text Available Riparian ecosystems integrate aquatic and terrestrial communities and often contain unique assemblages of flora and fauna. Retention of forested buffers along riparian habitats is a commonly employed practice to reduce potential negative effects of land use on aquatic systems. However, very few studies have examined long-term population and community responses to buffers, leading to considerable uncertainty about effectiveness of this practice for achieving conservation and management outcomes. We examined short- (1-2 years and long-term (~10 years avian community responses (occupancy and abundance to riparian buffer prescriptions to clearcut logging silvicultural practices in the Pacific Northwest USA. We used a Before-After-Control-Impact experimental approach and temporally replicated point counts analyzed within a Bayesian framework. Our experimental design consisted of forested control sites with no harvest, sites with relatively narrow (~13 m forested buffers on each side of the stream, and sites with wider (~30 m and more variable width unharvested buffer. Buffer treatments exhibited a 31-44% increase in mean species richness in the post-harvest years, a pattern most evident 10 years post-harvest. Post-harvest, species turnover was much higher on both treatments (63-74% relative to the controls (29%. We did not find evidence of local extinction for any species but found strong evidence (no overlap in 95% credible intervals for an increase in site occupancy on both Narrow (short-term: 7%; long-term 29% and Wide buffers (short-term: 21%; long-term 93% relative to controls after harvest. We did not find a treatment effect on total avian abundance. When assessing relationships between buffer width and site level abundance of four riparian specialists, we did not find strong evidence of reduced abundance in Narrow or Wide buffers. Silviculture regulations in this region dictate average buffer widths on small and large permanent streams that

  15. Analysis of microbial populations, denitrification, and nitrous oxide production in riparian buffers

    Science.gov (United States)

    Riparian buffers are used extensively to protect water bodies from nonpoint source nitrogen pollution. However there is relatively little information on the impact of these buffers on production of nitrous oxide (N2O). In this study, we assessed nitrous oxide production in riparian buffers of the so...

  16. Reconnecting tile drainage to riparian buffer hydrology for enhanced nitrate removal.

    Science.gov (United States)

    Jaynes, D B; Isenhart, T M

    2014-03-01

    Riparian buffers are a proven practice for removing NO from overland flow and shallow groundwater. However, in landscapes with artificial subsurface (tile) drainage, most of the subsurface flow leaving fields is passed through the buffers in drainage pipes, leaving little opportunity for NO removal. We investigated the feasibility of re-routing a fraction of field tile drainage as subsurface flow through a riparian buffer for increasing NO removal. We intercepted an existing field tile outlet draining a 10.1-ha area of a row-cropped field in central Iowa and re-routed a fraction of the discharge as subsurface flow along 335 m of an existing riparian buffer. Tile drainage from the field was infiltrated through a perforated pipe installed 75 cm below the surface by maintaining a constant head in the pipe at a control box installed in-line with the existing field outlet. During 2 yr, >18,000 m (55%) of the total flow from the tile outlet was redirected as infiltration within the riparian buffer. The redirected water seeped through the 60-m-wide buffer, raising the water table approximately 35 cm. The redirected tile flow contained 228 kg of NO. On the basis of the strong decrease in NO concentrations within the shallow groundwater across the buffer, we hypothesize that the NO did not enter the stream but was removed within the buffer by plant uptake, microbial immobilization, or denitrification. Redirecting tile drainage as subsurface flow through a riparian buffer increased its NO removal benefit and is a promising management practice to improve surface water quality within tile-drained landscapes. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  17. Nitrous oxide emission from cropland and adjacent riparian buffers in contrasting hydrogeomorphic settings.

    Science.gov (United States)

    Fisher, K; Jacinthe, P A; Vidon, P; Liu, X; Baker, M E

    2014-01-01

    Riparian buffers are important nitrate (NO) sinks in agricultural watersheds, but limited information is available regarding the intensity and control of nitrous oxide (NO) emission from these buffers. This study monitored (December 2009-May 2011) NO fluxes at two agricultural riparian buffers in the White River watershed in Indiana to assess the impact of land use and hydrogeomorphologic (HGM) attributes on emission. The study sites included a riparian forest in a glacial outwash/alluvium setting (White River [WR]) and a grassed riparian buffer in tile-drained till plains (Leary Weber Ditch [LWD]). Adjacent corn ( L.) fields were monitored for land use assessment. Analysis of variance identified season, land use (riparian buffer vs. crop field), and site geomorphology as major drivers of NO fluxes. Strong relationships between N mineralization and NO fluxes were found at both sites, but relationships with other nutrient cycling indicators (C/N ratio, dissolved organic C, microbial biomass C) were detected only at LWD. Nitrous oxide emission showed strong seasonal variability; the largest NO peaks occurred in late spring/early summer as a result of flooding at the WR riparian buffer (up to 27.8 mg NO-N m d) and N fertilizer application to crop fields. Annual NO emission (kg NO-N ha) was higher in the crop fields (WR: 7.82; LWD: 6.37) than in the riparian areas. A significant difference ( LWD, respectively), and this difference was attributed to site geomorphology and flooding (WR is flood prone; no flooding occurred at tile-drained LWD). The study results demonstrate the significance of landscape geomorphology and land-stream connection (i.e., flood potential) as drivers of NO emission in riparian buffers and therefore argue that an HGM-based approach should be especially suitable for determination of regional NO budget in riparian ecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  18. Hydrogeological constraints on riparian buffers for reduction of diffuse pollution: examples from the Bear Creek watershed in Iowa, USA.

    Science.gov (United States)

    Simpkins, W W; Wineland, T R; Andress, R J; Johnston, D A; Caron, G C; Isenhart, T M; Schultz, R C

    2002-01-01

    Riparian Management Systems (RiMS) have been proposed to minimize the impacts of agricultural production and improve water quality in Iowa in the Midwestern USA. As part of RiMS, multispecies riparian buffers have been shown to decrease nutrient, pesticide, and sediment concentrations in runoff from adjacent crop fields. However, their effect on nutrients and pesticides moving in groundwater beneath buffers has been discussed only in limited and idealized hydrogeologic settings. Studies in the Bear Creek watershed of central Iowa show the variability inherent in hydrogeologic systems at the watershed scale, some of which may be favorable or unfavorable to future implementation of buffers. Buffers may be optimized by choosing hydrogeologic systems where a shallow groundwater flow system channels water directly through the riparian buffer at velocities that allow for processes such as denitrification to occur.

  19. Enhanced transpiration by riparian buffer trees in response to advection in a humid temperate agricultural landscape

    Science.gov (United States)

    Hernandez-Santana, V.; Asbjornsen, H.; Sauer, T.; Isenhart, T.; Schilling, K.; Schultz, Ronald

    2011-01-01

    Riparian buffers are designed as management practices to increase infiltration and reduce surface runoff and transport of sediment and nonpoint source pollutants from crop fields to adjacent streams. Achieving these ecosystem service goals depends, in part, on their ability to remove water from the soil via transpiration. In these systems, edges between crop fields and trees of the buffer systems can create advection processes, which could influence water use by trees. We conducted a field study in a riparian buffer system established in 1994 under a humid temperate climate, located in the Corn Belt region of the Midwestern U.S. (Iowa). The goals were to estimate stand level transpiration by the riparian buffer, quantify the controls on water use by the buffer system, and determine to what extent advective energy and tree position within the buffer system influence individual tree transpiration rates. We primarily focused on the water use response (determined with the Heat Ratio Method) of one of the dominant species (Acer saccharinum) and a subdominant (Juglans nigra). A few individuals of three additional species (Quercus bicolor, Betula nigra, Platanus occidentalis) were monitored over a shorter time period to assess the generality of responses. Meteorological stations were installed along a transect across the riparian buffer to determine the microclimate conditions. The differences found among individuals were attributed to differences in species sap velocities and sapwood depths, location relative to the forest edge and prevailing winds and canopy exposure and dominance. Sapflow rates for A. saccharinum trees growing at the SE edge (prevailing winds) were 39% greater than SE interior trees and 30% and 69% greater than NW interior and edge trees, respectively. No transpiration enhancement due to edge effect was detected in the subdominant J. nigra. The results were interpreted as indicative of advection effects from the surrounding crops. Further, significant

  20. EnviroAtlas - Paterson, NJ - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. EnviroAtlas defines tree buffer for this community as only trees and forest. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  1. EnviroAtlas - Paterson, NJ - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. EnviroAtlas defines vegetated buffer for this community as trees and forest and grass and herbaceous. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  2. Finite Element Simulation of Total Nitrogen Transport in Riparian Buffer in an Agricultural Watershed

    Directory of Open Access Journals (Sweden)

    Xiaosheng Lin

    2016-03-01

    Full Text Available Riparian buffers can influence water quality in downstream lakes or rivers by buffering non-point source pollution in upstream agricultural fields. With increasing nitrogen (N pollution in small agricultural watersheds, a major function of riparian buffers is to retain N in the soil. A series of field experiments were conducted to monitor pollutant transport in riparian buffers of small watersheds, while numerical model-based analysis is scarce. In this study, we set up a field experiment to monitor the retention rates of total N in different widths of buffer strips and used a finite element model (HYDRUS 2D/3D to simulate the total N transport in the riparian buffer of an agricultural non-point source polluted area in the Liaohe River basin. The field experiment retention rates for total N were 19.4%, 26.6%, 29.5%, and 42.9% in 1,3,4, and 6m-wide buffer strips, respectively. Throughout the simulation period, the concentration of total N of the 1mwide buffer strip reached a maximum of 1.27 mg/cm3 at 30 min, decreasing before leveling off. The concentration of total N about the 3mwide buffer strip consistently increased, with a maximum of 1.05 mg/cm3 observed at 60 min. Under rainfall infiltration, the buffer strips of different widths showed a retention effect on total N transport, and the optimum effect was simulated in the 6mwide buffer strip. A comparison between measured and simulated data revealed that finite element simulation could simulate N transport in the soil of riparian buffer strips.

  3. Function, Design, and Establishment of Riparian Forest Buffers: A Review

    OpenAIRE

    Klapproth, Julia Caldwell

    1999-01-01

    Through the interaction of their soils, hydrology, and biotic communities, riparian forests protect and improve water quality, provide habitat for plants and animals, support aquatic communities, and provide many benefits to humans. Virginia, along with other states in the Chesapeake Bay region, has recognized the importance of riparian forests by implementing a plan to restore forested buffers along streams, rivers, and lakes. This project reviews selected literature on riparian forest bu...

  4. Riparian forest buffers mitigate the effects of deforestation on fish assemblages in tropical headwater streams.

    Science.gov (United States)

    Lorion, Christopher M; Kennedy, Brian P

    2009-03-01

    Riparian forest buffers may play a critical role in moderating the impacts of deforestation on tropical stream ecosystems, but very few studies have examined the ecological effects of riparian buffers in the tropics. To test the hypothesis that riparian forest buffers can reduce the impacts of deforestation on tropical stream biota, we sampled fish assemblages in lowland headwater streams in southeastern Costa Rica representing three different treatments: (1) forested reference stream reaches, (2) stream reaches adjacent to pasture with a riparian forest buffer averaging at least 15 m in width on each bank, and (3) stream reaches adjacent to pasture without a riparian forest buffer. Land cover upstream from the study reaches was dominated by forest at all of the sites, allowing us to isolate the reach-scale effects of the three study treatments. Fish density was significantly higher in pasture reaches than in forest and forest buffer reaches, mostly due to an increase in herbivore-detritivores, but fish biomass did not differ among reach types. Fish species richness was also higher in pasture reaches than in forested reference reaches, while forest buffer reaches were intermediate. Overall, the taxonomic and trophic structure of fish assemblages in forest and forest buffer reaches was very similar, while assemblages in pasture reaches were quite distinct. These patterns were persistent across three sampling periods during our 15-month study. Differences in stream ecosystem conditions between pasture reaches and forested sites, including higher stream temperatures, reduced fruit and seed inputs, and a trend toward increased periphyton abundance, appeared to favor fish species normally found in larger streams and facilitate a native invasion process. Forest buffer reaches, in contrast, had stream temperatures and allochthonous inputs more similar to forested streams. Our results illustrate the importance of riparian areas to stream ecosystem integrity in the tropics

  5. EnviroAtlas - Durham, NC - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).

  6. EnviroAtlas - Portland, Maine - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  7. EnviroAtlas - Portland, ME - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  8. EnviroAtlas - Austin, TX - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  9. EnviroAtlas - Memphis, TN - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. Forest is defined as Trees & Forest and Woody Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  10. EnviroAtlas - Portland, OR - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (http:/www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  11. EnviroAtlas - Milwaukee, WI - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  12. EnviroAtlas - Pittsburgh, PA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  13. EnviroAtlas - Fresno, CA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  14. EnviroAtlas - Woodbine, Iowa - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  15. EnviroAtlas - Phoenix, AZ - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  16. EnviroAtlas - Phoenix, AZ - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  17. EnviroAtlas - Tampa, FL - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  18. EnviroAtlas - Woodbine, IA - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  19. EnviroAtlas - Milwaukee, WI - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  20. EnviroAtlas - Portland, OR - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (http:/www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  1. EnviroAtlas - Cleveland, OH - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest and Woody Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  2. EnviroAtlas - Pittsburgh, PA - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  3. EnviroAtlas - Fresno, CA - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  4. EnviroAtlas - Durham, NC - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).

  5. EnviroAtlas - Tampa, FL - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  6. EnviroAtlas - Austin, TX - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. Forest is defined as Trees & Forest. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  7. Assessing critical source areas in watersheds for conservation buffer planning and riparian restoration.

    Science.gov (United States)

    Qiu, Zeyuan

    2009-11-01

    A science-based geographic information system (GIS) approach is presented to target critical source areas in watersheds for conservation buffer placement. Critical source areas are the intersection of hydrologically sensitive areas and pollutant source areas in watersheds. Hydrologically sensitive areas are areas that actively generate runoff in the watershed and are derived using a modified topographic index approach based on variable source area hydrology. Pollutant source areas are the areas in watersheds that are actively and intensively used for such activities as agricultural production. The method is applied to the Neshanic River watershed in Hunterdon County, New Jersey. The capacity of the topographic index in predicting the spatial pattern of runoff generation and the runoff contribution to stream flow in the watershed is evaluated. A simple cost-effectiveness assessment is conducted to compare the conservation buffer placement scenario based on this GIS method to conventional riparian buffer scenarios for placing conservation buffers in agricultural lands in the watershed. The results show that the topographic index reasonably predicts the runoff generation in the watershed. The GIS-based conservation buffer scenario appears to be more cost-effective than the conventional riparian buffer scenarios.

  8. Biomass carbon, nitrogen and phosphorus stocks in hybrid poplar buffers, herbaceous buffers and natural woodlots in the riparian zone on agricultural land.

    Science.gov (United States)

    Fortier, Julien; Truax, Benoit; Gagnon, Daniel; Lambert, France

    2015-05-01

    In many temperate agricultural areas, riparian forests have been converted to cultivated land, and only narrow strips of herbaceous vegetation now buffer many farm streams. The afforestation of these riparian zones has the potential to increase carbon (C) storage in agricultural landscapes by creating a new biomass sink for atmospheric CO2. Occurring at the same time, the storage of nitrogen (N) and phosphorus (P) in plant biomass, is an important water quality function that may greatly vary with types of riparian vegetation. The objectives of this study were (1) to compare C, N and P storage in aboveground, belowground and detrital biomass for three types of riparian vegetation cover (9-year-old hybrid poplar buffers, herbaceous buffers and natural woodlots) across four agricultural sites and (2) to determine potential vegetation cover effects on soil nutrient supply rate in the riparian zone. Site level comparisons suggest that 9-year-old poplar buffers have stored 9-31 times more biomass C, 4-10 times more biomass N, and 3-7 times more biomass P than adjacent non managed herbaceous buffers, with the largest differences observed on the more fertile sites. The conversion of these herbaceous buffers to poplar buffers could respectively increase C, N and P storage in biomass by 3.2-11.9 t/ha/yr, 32-124 kg/ha/yr and 3.2-15.6 kg/ha/yr, over 9 years. Soil NO3 and P supply rates during the summer were respectively 57% and 66% lower in poplar buffers than in adjacent herbaceous buffers, potentially reflecting differences in nutrient storage and cycling between the two buffer types. Biomass C ranged 49-160 t/ha in woodlots, 33-110 t/ha in poplar buffers and 3-4 t/ha in herbaceous buffers. Similar biomass C stocks were found in the most productive poplar buffer and three of the four woodlots studied. Given their large and varied biomass C stocks, conservation of older riparian woodlots is equally important for C balance management in farmland. In addition, the

  9. EnviroAtlas - Cleveland, OH - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees & Forest, Grass & Herbaceous, Woody Wetlands, and Emergent Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas ) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  10. EnviroAtlas - Memphis, TN - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest, Grass & Herbaceous, Woody Wetlands, and Emergent Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  11. Connecting Seasonal Riparian Buffer Metrics and Nitrogen Concentrations in a Pulse-Driven Agricultural System

    Science.gov (United States)

    Riparian buffers have been well studied as best management practices for nutrient reduction at field scales yet their effectiveness for bettering water quality at watershed scales has been difficult to determine. Seasonal dynamics of the stream network are often overlooked when ...

  12. Nitrogen transformation and retention in riparian buffer zones

    NARCIS (Netherlands)

    Hefting, Maria Margaretha

    2003-01-01

    Diffuse pollution of nutrients and pesticides from agricultural areas is increasingly recognised as a major problem in water management. Ecotechnological measures as constructed wetlands and riparian buffer zones clearly have an important role in the reduction of diffuse pollution by removing and

  13. Soil water nitrate concentrations in giant cane and forest riparian buffer zones

    Science.gov (United States)

    Jon E. Schoonover; Karl W. J. Williard; James J. Zaczek; Jean C. Mangun; Andrew D. Carver

    2003-01-01

    Soil water nitrate concentrations in giant cane and forest riparian buffer zones along Cypress Creek in southern Illinois were compared to determine if the riparian zones were sources or sinks for nitrogen in the rooting zone. Suction lysimeters were used to collect soil water samples from the lower rooting zone in each of the two vegetation types. The cane riparian...

  14. EnviroAtlas - New Bedford, MA - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  15. EnviroAtlas - Des Moines, IA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. Forest is defined as Trees & Forest. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://enviroatlas.epa.gov/EnviroAtlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  16. EnviroAtlas - New York, NY - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  17. EnviroAtlas - Green Bay, WI - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).

  18. EnviroAtlas - Des Moines, IA - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. Vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://enviroatlas.epa.gov/EnviroAtlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  19. EnviroAtlas - Green Bay, WI - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area.This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets ).

  20. EnviroAtlas - New Bedford, MA - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the Atlas Area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  1. Thinning and riparian buffer configuration effects on down wood abundance in headwater streams in coniferous forests

    Science.gov (United States)

    Adrian Ares; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Down wood is associated with the function, structure, and diversity of riparian systems. Considerable knowledge has been generated regarding down wood stocks and dynamics in temperate forests, but there are few studies on effects of silvicultural practices and riparian buffer design on down wood, particularly in headwater streams. We analyzed interactive eff ects of...

  2. Costs of Producing Biomass from Riparian Buffer Strips

    Energy Technology Data Exchange (ETDEWEB)

    Turhollow, A.

    2000-09-01

    Nutrient runoff from poultry litter applied to agricultural fields in the Delmarva Peninsula contributes to high nutrient loadings in Chesapeake Bay. One potential means of ameliorating this problem is the use of riparian buffer strips. Riparian buffer strips intercept overland flows of water, sediments, nutrients, and pollutants; and ground water flows of nutrients and pollutants. Costs are estimated for three biomass systems grown on buffer strips: willow planted at a density of 15,300 trees/ha (6200 trees/acre); poplar planted at a density of 1345 trees/ha (545 trees/acre); and switchgrass. These costs are estimated for five different scenarios: (1) total economic costs, where everything is costed [cash costs, noncash costs (e.g., depreciation), land rent, labor]; (2) costs with Conservation Reserve Program (CRP) payments (which pays 50% of establishment costs and an annual land rent); (3) costs with enhanced CRP payments (which pays 95% of establishment costs and an annual payment of approximately 170% of land rent for trees and 150% of land rent for grasses); (4) costs when buffer strips are required, but harvest of biomass is not required [costs borne by biomass are for yield enhancing activities (e.g., fertilization), harvest, and transport]; and (5) costs when buffer strips are required. and harvest of biomass is required to remove nutrients (costs borne by biomass are for yield enhancing activities and transport). CRP regulations would have to change to allow harvest. Delivered costs of willow, poplar, and switchgrass [including transportation costs of $0.38/GJ ($0.40/million Btu) for switchgrass and $0.57/GJ ($0.60/million Btu) for willow and poplar] at 11.2 dry Mg/ha-year (5 dry tons/acre-year) for the five cost scenarios listed above are [$/GJ ($million BIN)]: (1) 3.30-5.45 (3.45-5.75); (2) 2.30-3.80 (2.45-4.00); (3) 1.70-2.45 (1.80-2.60); (4) l-85-3.80 (1.95-4.05); and (5) 0.80-1.50 (0.85-1.60). At yields of 15.7 to 17.9 GJ/ha-year (7 to 8 dry tons

  3. RESEARCH SHOWS IMPORTANCE OF RIPARIAN BUFFERS FOR AQUATIC HEALTH

    Science.gov (United States)

    Issue: Excess nitrogen from fertilizer, septic tanks, animal feedlots, and runoff from pavement can threaten aquatic ecosystem health. Riparian buffers -- the vegetated region adjacent to streams and wetlands -- are thought to be effective at intercepting and controlling excess ...

  4. Microbial community structure across a wastewater-impacted riparian buffer zone in the southeastern coastal plain.

    Science.gov (United States)

    Ducey, T F; Johnson, P R; Shriner, A D; Matheny, T A; Hunt, P G

    2013-01-01

    Riparian buffer zones are important for both natural and developed ecosystems throughout the world because of their ability to retain nutrients, prevent soil erosion, protect aquatic environments from excessive sedimentation, and filter pollutants. Despite their importance, the microbial community structures of riparian buffer zones remains poorly defined. Our objectives for this study were twofold: first, to characterize the microbial populations found in riparian buffer zone soils; and second, to determine if microbial community structure could be linked to denitrification enzyme activity (DEA). To achieve these objectives, we investigated the microbial populations of a riparian buffer zone located downslope of a pasture irrigated with swine lagoon effluent, utilizing DNA sequencing of the 16S rDNA, DEA, and quantitative PCR (qPCR) of the denitrification genes nirK, nirS, and nosZ. Clone libraries of the 16S rDNA gene were generated from each of twelve sites across the riparian buffer with a total of 986 partial sequences grouped into 654 operational taxonomic units (OTUs). The Proteobacteria were the dominant group (49.8% of all OTUs), with the Acidobacteria also well represented (19.57% of all OTUs). Analysis of qPCR results identified spatial relationships between soil series, site location, and gene abundance, which could be used to infer both incomplete and total DEA rates.

  5. EnviroAtlas - New York, NY - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees & Forest and Grass & Herbaceous. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets)

  6. Do Riparian Buffers Protect Stream Invertebrate Communities in South American Atlantic Forest Agricultural Areas?

    Science.gov (United States)

    Hunt, L.; Marrochi, N.; Bonetto, C.; Liess, M.; Buss, D. F.; Vieira da Silva, C.; Chiu, M.-C.; Resh, V. H.

    2017-12-01

    We investigated the influence and relative importance of insecticides and other agricultural stressors in determining variability in invertebrate communities in small streams in intensive soy-production regions of Brazil and Paraguay. In Paraguay we sampled 17 sites on tributaries of the Pirapó River in the state of Itapúa and in Brazil we sampled 18 sites on tributaries of the San Francisco River in the state of Paraná. The riparian buffer zones generally contained native Atlantic forest remnants and/or introduced tree species at various stages of growth. In Brazil the stream buffer width was negatively correlated with sediment insecticide concentrations and buffer width was found to have moderate importance in mitigating effects on some sensitive taxa such as mayflies. However, in both regions insecticides had low relative importance in explaining variability in invertebrate communities, while various habitat parameters were more important. In Brazil, the percent coverage of soft depositional sediment in streams was the most important agriculture-related explanatory variable, and the overall stream-habitat score was the most important variable in Paraguay streams. Paraguay and Brazil both have laws requiring forested riparian buffers. The ample forested riparian buffer zones typical of streams in these regions are likely to have mitigated the effects of pesticides on stream invertebrate communities. This study provides evidence that riparian buffer regulations in the Atlantic Forest region are protecting stream ecosystems from pesticides and other agricultural stressors. Further studies are needed to determine the minimum buffer widths necessary to achieve optimal protection.

  7. Effects of riparian buffer width on wood loading in headwater streams after repeated forest thinning

    Science.gov (United States)

    Julia I. Burton; Deanna H. Olson; Klaus J. Puettmann

    2016-01-01

    Forested riparian buffer zones are used in conjunction with upland forest management, in part, to provide for the recruitment for large wood to streams. Small headwater streams account for the majority of stream networks in many forested regions. Yet, our understanding of how riparian buffer width influences wood dynamics in headwater streams is relatively less...

  8. Assessing Anthropogenic Influence and Edge Effect Influence on Forested Riparian Buffer Spatial Configuration and Structure: An Example Using Lidar Remote Sensing Methods

    Science.gov (United States)

    Wasser, L. A.; Chasmer, L. E.

    2012-12-01

    Forested riparian buffers (FRB) perform numerous critical ecosystem services. However, globally, FRB spatial configuration and structure have been modified by anthropogenic development resulting in widespread ecological degradation as seen in the Gulf of Mexico and the Chesapeake Bay. Riparian corridors within developed areas are particularly vulnerable to disturbance given two edges - the naturally occurring stream edge and the matrix edge. Increased edge length predisposes riparian vegetation to "edge effects", characterized by modified physical and environmental conditions at the interface between the forested buffer and the adjacent landuse, or matrix and forest fragment degradation. The magnitude and distance of edge influence may be further influenced by adjacent landuse type and the width of the buffer corridor at any given location. There is a need to quantify riparian buffer spatial configuration and structure over broad geographic extents and within multiple riparian systems in support of ecologically sound management and landuse decisions. This study thus assesses the influence of varying landuse types (agriculture, suburban development and undeveloped) on forested riparian buffer 3-dimensional structure and spatial configuration using high resolution Light Detection and Ranging (LiDAR) data collected within a headwater watershed. Few studies have assessed riparian buffer structure and width contiguously for an entire watershed, an integral component of watershed planning and restoration efforts such as those conducted throughout the Chesapeake Bay. The objectives of the study are to 1) quantify differences in vegetation structure at the stream and matrix influenced riparian buffer edges, compared to the forested interior and 2) assess continuous patterns of changes in vegetation structure throughout the buffer corridor beginning at the matrix edge and ending at the stream within buffers a) of varying width and b) that are adjacent to varying landuse

  9. Identifying Riparian Buffer Effects on Stream 1 Nitrogen in Southeastern Coastal Plain Watersheds

    Science.gov (United States)

    Riparian areas have long demonstrated their ability to attenuate nutrients and sediments from agricultural runoff at the field scale; however, to inform effective nutrient management choices, the impact of riparian buffers on water quality services must be assessed at watershed s...

  10. EnviroAtlas - Cleveland, OH - 51m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees & Forest,...

  11. EnviroAtlas - Cleveland, OH - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest and Woody...

  12. EnviroAtlas - Durham, NC - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  13. EnviroAtlas - Phoenix, AZ - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  14. EnviroAtlas - Memphis, TN - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. Forest is defined as Trees & Forest and Woody Wetlands. There is a...

  15. EnviroAtlas - Portland, ME - 51m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the...

  16. EnviroAtlas - Portland, OR - 15m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the...

  17. EnviroAtlas - Tampa, FL - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  18. EnviroAtlas - Fresno, CA - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  19. EnviroAtlas - Woodbine, IA - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. There is a potential for decreased water quality in areas where the...

  20. EnviroAtlas - Phoenix, AZ - 51m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the...

  1. EnviroAtlas - Durham, NC - 51m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the...

  2. EnviroAtlas - Woodbine, IA - 15m Riparian Buffer Vegetated Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is vegetated. There is a potential for decreased water quality in areas where the...

  3. [Retaining and transformation of incoming soil N from highland to adjacent terrestrial water body in riparian buffer zone].

    Science.gov (United States)

    Wang, Qing-cheng; Yu, Hong-li; Yao, Qin; Han, Zhuang-xing; Qiao, Shu-liang

    2007-11-01

    Highland soil nitrogen can enter adjacent water body via erosion and leaching, being one of the important pollutants in terrestrial water bodies. Riparian buffer zone is a transitional zone between highland and its adjacent water body, and a healthy riparian buffer zone can retain and transform the incoming soil N through physical, biological, and biochemical processes. In this paper, the major pathways through which soil nitrogen enters terrestrial water body and the mechanisms the nitrogen was retained and transformed in riparian buffer zone were introduced systematically, and the factors governing the nitrogen retaining and transformation were analyzed from the aspects of hydrological processes, soil characters, vegetation features, and human activities. The problems existing in riparian buffer zone study were discussed, and some suggestions for the further study in China were presented.

  4. EnviroAtlas - Minneapolis/St. Paul, MN - 51m Riparian Buffer Forest Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees and Forest and Woody Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less forested. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  5. EnviroAtlas - Minneapolis/St. Paul, MN - 51m Riparian Buffer Vegetated Cover

    Science.gov (United States)

    This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is vegetated. In this community, vegetated cover is defined as Trees and Forest, Grass and Herbaceous, Woody Wetlands, and Emergent Wetlands. There is a potential for decreased water quality in areas where the riparian buffer is less vegetated. The displayed line represents the center of the analyzed riparian buffer. The water bodies analyzed include hydrologically connected streams, rivers, connectors, reservoirs, lakes/ponds, ice masses, washes, locks, and rapids within the EnviroAtlas community area. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).

  6. EnviroAtlas - New York, NY - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest. There is a...

  7. EnviroAtlas - New York, NY - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees & Forest. There is a...

  8. Denitrification gene density across a wastewater-impacted riparian buffer zone

    Science.gov (United States)

    Riparian buffers are a best management practice used extensively to protect water bodies from agriculturally-generated nitrate pollution. In particular, the biological process of denitrification has been shown to be a sink for this nitrate. Denitrification results in the reduction of nitrate under a...

  9. EnviroAtlas - Minneapolis/St. Paul, MN - 51m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 51-m riparian buffer that is forested. In this community, forest is defined as Trees and Forest and Woody...

  10. EnviroAtlas - Minneapolis/St. Paul, MN - 15m Riparian Buffer Forest Cover

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset describes the percentage of a 15-m riparian buffer that is forested. In this community, forest is defined as Trees and Forest and Woody...

  11. Riparian buffer and density management influences on microclimate of young headwater forests of Western Oregon.

    Science.gov (United States)

    Paul D. Anderson; David J. Larson; Samuel S. Chan

    2007-01-01

    Thinning of 30- to 70-year-old Douglas-fir (Psuedotsuga menziesii [Mirb.] Franco) stands is a common silvicultural activity on federal forest lands of the Pacific Northwest, United States. Empirical relationships among riparian functions, silvicultural treatments, and different riparian buffer widths are not well documented for small headwater...

  12. Spatial and temporal analysis of the land cover in riparian buffer zones (Areas for Permanent Preservation in Sorocaba City, SP, Brazil

    Directory of Open Access Journals (Sweden)

    Sergio Henrique Alves

    2009-08-01

    Full Text Available Considering the fundamental role that the riparian vegetation plays in relation to maintenance of the environmental health of a watershed and the necessity of restoring sectors of the buffer zone without natural vegetation, in this paper we investigated what land cover classes occur along the riparian buffer stripes considered Area for Permanent Preservation (APP in the Sorocaba municipality, SP in three periods: 1988, 1995 and 2003. Based on GIS technology and using the drainage network map, the APP stripes (riparian buffer zones map was generated, and this map was overlaid to the land cover map (1988, 1995 and 2003 to provide a land cover map specifically of the riparian buffer zones. The results show that 58.43% of the APPs have no land cover of native vegetation and therefore, need to be reforested, representing 5,400 hectares to be restored.

  13. RESTORED RIPARIAN BUFFERS AS TOOLS FOR ECOSYSTEM RESTORATION IN THE MAIA PROCESSES, ENDPOINTS, AND MEASURES OF SUCCESS FOR WATER, SOIL, FLORA AND FAUNA

    Science.gov (United States)

    Riparian buffer restorations are used as management tools to produce favorable water quality impacts, moreover the basis for riparian buffers as an instrument of water quality restoration rests on a relatively firm foundation. However, the extent to which buffers can restore rip...

  14. Water Quality Changes in a Short-Rotation Woody Crop Riparian Buffer

    Science.gov (United States)

    Rosa, D.; Clausen, J.; Kuzovkina, J.

    2016-12-01

    Converting riparian buffers in agricultural areas from annual row crops to short rotation woody crops (SRWCs) grown for biofuel can provide both water quality benefits and a financial incentive for buffer adoption among agricultural producers. A randomized complete block design was used to determine water quality changes resulting from converting plots previously cultivated in corn to SRWC willow (Salix. spp) adjacent to a stream in Storrs, CT. Both overland flow and ground water samples were analyzed for total nitrogen (TN), nitrate + nitrite (NO2+NO3-N), and total phosphorus (TP). Overland flow was also analyzed for suspended solids concentration (SSC). Lower (p = 0.05) concentrations of TN (56%) and TP (61%) were observed in post-coppice surface runoff from willow plots than from corn plots. Shallow ground water concentrations at the edge of willow plots were lower in TN (56%) and NO3+NO2-N (64%), but 35% higher in TP, than at the edge of corn plots. SSC was also lower (72%) in overland flow associated with willow compared to corn. The treatment had no effect on discharge or mass export. These results suggest conversion from corn to a SRWC in a riparian area can provide water quality benefits similar to those observed in restored and established buffers.

  15. Model analysis of riparian buffer effectiveness for reducing nutrient inputs to streams in agricultural landscapes

    Science.gov (United States)

    McKane, R. B.; M, S.; F, P.; Kwiatkowski, B. L.; Rastetter, E. B.

    2006-12-01

    Federal and state agencies responsible for protecting water quality rely mainly on statistically-based methods to assess and manage risks to the nation's streams, lakes and estuaries. Although statistical approaches provide valuable information on current trends in water quality, process-based simulation models are essential for understanding and forecasting how changes in human activities across complex landscapes impact the transport of nutrients and contaminants to surface waters. To address this need, we developed a broadly applicable, process-based watershed simulator that links a spatially-explicit hydrologic model and a terrestrial biogeochemistry model (MEL). See Stieglitz et al. and Pan et al., this meeting, for details on the design and verification of this simulator. Here we apply the watershed simulator to a generalized agricultural setting to demonstrate its potential for informing policy and management decisions concerning water quality. This demonstration specifically explores the effectiveness of riparian buffers for reducing the transport of nitrogenous fertilizers from agricultural fields to streams. The interaction of hydrologic and biogeochemical processes represented in our simulator allows several important questions to be addressed. (1) For a range of upland fertilization rates, to what extent do riparian buffers reduce nitrogen inputs to streams? (2) How does buffer effectiveness change over time as the plant-soil system approaches N-saturation? (3) How can buffers be managed to increase their effectiveness, e.g., through periodic harvest and replanting? The model results illustrate that, while the answers to these questions depend to some extent on site factors (climatic regime, soil properties and vegetation type), in all cases riparian buffers have a limited capacity to reduce nitrogen inputs to streams where fertilization rates approach those typically used for intensive agriculture (e.g., 200 kg N per ha per year for corn in the U

  16. Imidacloprid sorption and transport in cropland, grass buffer and riparian buffer soils

    Science.gov (United States)

    Satkowski, Laura E.; Goyne, Keith W.; Anderson, Stephen H.; Lerch, Robert N.; Allen, Craig R.; Snow, Daniel D.

    2018-01-01

    An understanding of neonicotinoid sorption and transport in soil is critical for determining and mitigating environmental risk associated with the most widely used class of insecticides. The objective of this study was to evaluate mobility and transport of the neonicotinoid imidacloprid (ICD) in soils collected from cropland, grass vegetative buffer strip (VBS), and riparian VBS soils. Soils were collected at six randomly chosen sites within grids that encompassed all three land uses. Single-point equilibrium batch sorption experiments were conducted using radio-labeled (14C) ICD to determine solid–solution partition coefficients (Kd). Column experiments were conducted using soils collected from the three vegetation treatments at one site by packing soil into glass columns. Water flow was characterized by applying Br− as a nonreactive tracer. A single pulse of 14C-ICD was then applied, and ICD leaching was monitored for up to 45 d. Bromide and ICD breakthrough curves for each column were simulated using CXTFIT and HYDRUS-1D models. Sorption results indicated that ICD sorbs more strongly to riparian VBS (Kd = 22.6 L kg−1) than crop (Kd = 11.3 L kg−1) soils. Soil organic C was the strongest predictor of ICD sorption (p < 0.0001). The column transport study found mean peak concentrations of ICD at 5.83, 10.84, and 23.8 pore volumes for crop, grass VBS, and riparian VBS soils, respectively. HYDRUS-1D results indicated that the two-site, one-rate linear reversible model best described results of the breakthrough curves, indicating the complexity of ICD sorption and demonstrating its mobility in soil. Greater sorption and longer retention by the grass and riparian VBS soils than the cropland soil suggests that VBS may be a viable means to mitigate ICD loss from agroecosystems, thereby preventing ICD transport into surface water, groundwater, or drinking water resources.

  17. Litter Controls Earthworm-Mediated Carbon and Nitrogen Transformations in Soil from Temperate Riparian Buffers

    OpenAIRE

    Maria Kernecker; Joann K. Whalen; Robert L. Bradley

    2014-01-01

    Nutrient cycling in riparian buffers is partly influenced by decomposition of crop, grass, and native tree species litter. Nonnative earthworms in riparian soils in southern Quebec are expected to speed the processes of litter decomposition and nitrogen (N) mineralization, increasing carbon (C) and N losses in gaseous forms or via leachate. A 5-month microcosm experiment evaluated the effect of Aporrectodea turgida on the decomposition of 3 litter types (deciduous leaves, reed canarygrass, an...

  18. Fit-for-purpose phosphorus management: do riparian buffers qualify in catchments with sandy soils?

    Science.gov (United States)

    Weaver, David; Summers, Robert

    2014-05-01

    Hillslope runoff and leaching studies, catchment-scale water quality measurements and P retention and release characteristics of stream bank and catchment soils were used to better understand reasons behind the reported ineffectiveness of riparian buffers for phosphorus (P) management in catchments with sandy soils from south-west Western Australia (WA). Catchment-scale water quality measurements of 60 % particulate P (PP) suggest that riparian buffers should improve water quality; however, runoff and leaching studies show 20 times more water and 2 to 3 orders of magnitude more P are transported through leaching than runoff processes. The ratio of filterable reactive P (FRP) to total P (TP) in surface runoff from the plots was 60 %, and when combined with leachate, 96 to 99 % of P lost from hillslopes was FRP, in contrast with 40 % measured as FRP at the large catchment scale. Measurements of the P retention and release characteristics of catchment soils (bank soil (bank soils suggest that catchment soils contain more P, are more P saturated and are significantly more likely to deliver FRP and TP in excess of water quality targets than stream bank soils. Stream bank soils are much more likely to retain P than contribute P to streams, and the in-stream mixing of FRP from the landscape with particulates from stream banks or stream beds is a potential mechanism to explain the change in P form from hillslopes (96 to 99 % FRP) to large catchments (40 % FRP). When considered in the context of previous work reporting that riparian buffers were ineffective for P management in this environment, these studies reinforce the notion that (1) riparian buffers are unlikely to provide fit-for-purpose P management in catchments with sandy soils, (2) most P delivered to streams in sandy soil catchments is FRP and travels via subsurface and leaching pathways and (3) large catchment-scale water quality measurements are not good indicators of hillslope P mobilisation and transport

  19. Near-Term Effects of Repeated-Thinning with Riparian Buffers on Headwater Stream Vertebrates and Habitats in Oregon, USA

    Directory of Open Access Journals (Sweden)

    Deanna H. Olson

    2014-11-01

    Full Text Available We examined the effects of a second-thinning harvest with alternative riparian buffer management approaches on headwater stream habitats and associated vertebrates in western Oregon, USA. Our analyses showed that stream reaches were generally distinguished primarily by average width and depth, along with the percentage of the dry reach length, and secondarily, by the volume of down wood. In the first year post-harvest, we observed no effects of buffer treatment on stream habitat attributes after moderate levels of thinning. One of two “thin-through” riparian treatments showed stronger trends for enlarged stream channels, likely due to harvest disturbances. The effects of buffer treatments on salamanders varied among species and with habitat structure. Densities of Plethodon dunni and Rhyacotriton species increased post-harvest in the moderate-density thinning with no-entry buffers in wider streams with more pools and narrower streams with more down wood, respectively. However, Rhyacotriton densities decreased along streams with the narrowest buffer, 6 m, and P. dunni and Dicamptodon tenebrosus densities decreased in thin-through buffers. Our study supports the use of a 15-m or wider buffer to retain sensitive headwater stream amphibians.

  20. Litter Controls Earthworm-Mediated Carbon and Nitrogen Transformations in Soil from Temperate Riparian Buffers

    Directory of Open Access Journals (Sweden)

    Maria Kernecker

    2014-01-01

    Full Text Available Nutrient cycling in riparian buffers is partly influenced by decomposition of crop, grass, and native tree species litter. Nonnative earthworms in riparian soils in southern Quebec are expected to speed the processes of litter decomposition and nitrogen (N mineralization, increasing carbon (C and N losses in gaseous forms or via leachate. A 5-month microcosm experiment evaluated the effect of Aporrectodea turgida on the decomposition of 3 litter types (deciduous leaves, reed canarygrass, and soybean stem residue. Earthworms increased CO2 and N2O losses from microcosms with soybean residue, by 112% and 670%, respectively, but reduced CO2 and N2O fluxes from microcosms with reed canarygrass by 120% and 220%, respectively. Litter type controlled the CO2 flux (soybean ≥ deciduous-mix litter = reed canarygrass > no litter and the N2O flux (soybean ≥ no litter ≥ reed canarygrass > deciduous-mix litter. However, in the presence of earthworms, there was a slight increase in C and N gaseous losses of C and N relative to their losses via leachate, across litter treatments. We conclude that litter type determines the earthworm-mediated decomposition effect, highlighting the importance of vegetation management in controlling C and N losses from riparian buffers to the environment.

  1. Sediment measurement and transport modeling: impact of riparian and filter strip buffers.

    Science.gov (United States)

    Moriasi, Daniel N; Steiner, Jean L; Arnold, Jeffrey G

    2011-01-01

    Well-calibrated models are cost-effective tools to quantify environmental benefits of conservation practices, but lack of data for parameterization and evaluation remains a weakness to modeling. Research was conducted in southwestern Oklahoma within the Cobb Creek subwatershed (CCSW) to develop cost-effective methods to collect stream channel parameterization and evaluation data for modeling in watersheds with sparse data. Specifically, (i) simple stream channel observations obtained by rapid geomorphic assessment (RGA) were used to parameterize the Soil and Water Assessment Tool (SWAT) model stream channel variables before calibrating SWAT for streamflow and sediment, and (ii) average annual reservoir sedimentation rate, measured at the Crowder Lake using the acoustic profiling system (APS), was used to cross-check Crowder Lake sediment accumulation rate simulated by SWAT. Additionally, the calibrated and cross-checked SWAT model was used to simulate impacts of riparian forest buffer (RF) and bermudagrass [ (L.) Pers.] filter strip buffer (BFS) on sediment yield and concentration in the CCSW. The measured average annual sedimentation rate was between 1.7 and 3.5 t ha yr compared with simulated sediment rate of 2.4 t ha yr Application of BFS across cropped fields resulted in a 72% reduction of sediment delivery to the stream, while the RF and the combined RF and BFS reduced the suspended sediment concentration at the CCSW outlet by 68 and 73%, respectively. Effective riparian practices have potential to increase reservoir life. These results indicate promise for using the RGA and APS methods to obtain data to improve water quality simulations in ungauged watersheds. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

  2. Effects of thinning on transpiration by riparian buffer trees in response to advection and solar radiation

    Science.gov (United States)

    Advective energy occurring in edge environments may increase tree water use. In humid agricultural landscapes, advection-enhanced transpiration in riparian buffers may provide hydrologic regulation; however, research in humid environments is lacking. The objectives of this study were to determine ho...

  3. Water body and riparian buffer strip characteristics in a vineyard area to support aquatic pesticide exposure assessment.

    Science.gov (United States)

    Ohliger, Renja; Schulz, Ralf

    2010-10-15

    The implementation of a geodata-based probabilistic pesticide exposure assessment for surface waters in Germany offers the opportunity to base the exposure estimation on more differentiated assumptions including detailed landscape characteristics. Since these characteristics can only be estimated using field surveys, water body width and depth, hydrology, riparian buffer strip width, ground vegetation cover, existence of concentrated flow paths, and riparian vegetation were characterised at 104 water body segments in the vineyard region Palatinate (south-west Germany). Water body segments classified as permanent (n=43) had median values of water body width and depth of 0.9m and 0.06m, respectively, and the determined median width:depth ratio was 15. Thus, the deterministic water body model (width=1m; depth=0.3m) assumed in regulatory exposure assessment seems unsuitable for small water bodies in the study area. Only 25% of investigated buffer strips had a dense vegetation cover (>70%) and allow a laminar sheet flow as required to include them as an effective pesticide runoff reduction landscape characteristic. At 77 buffer strips, bordering field paths and erosion rills leading into the water body were present, concentrating pesticide runoff and consequently decreasing buffer strip efficiency. The vegetation type shrubbery (height>1.5m) was present at 57 (29%) investigated riparian buffer strips. According to their median optical vegetation density of 75%, shrubberies may provide a spray drift reduction of 72±29%. Implementing detailed knowledge in an overall assessment revealed that exposure via drift might be 2.4 and via runoff up to 1.6 fold higher than assumed by the deterministic approach. Furthermore, considering vegetated buffer strips only by their width leads to an underestimation of exposure by a factor of as much as four. Our data highlight that the deterministic model assumptions neither represent worst-case nor median values and therefore cannot

  4. Riparian buffer strips as a multifunctional management tool in agricultural landscapes: Introduction to the special collection

    NARCIS (Netherlands)

    Stutter, M.I.; Chardon, W.J.; Kronvang, B.

    2012-01-01

    Catchment riparian areas are considered key zones to target mitigation measures aimed at interrupting the movement of diffuse substances from agricultural land to surface waters. Hence, unfertilized buffer strips have become a widely studied and implemented “edge of field” mitigation measure assumed

  5. Width of riparian buffer and structure of adjacent plantations influence occupancy of conservation priority birds

    Science.gov (United States)

    Roger W. Perry; T. Bently Wigley; M. Anthony Melchiors; Ronald E. Thill; Philip A. Tappe; Darren A. Miller

    2011-01-01

    Conservation of biodiversity on forest landscapes dominated by plantations has become an increasingly important topic, and opportunities to maintain or enhance biodiversity within these forests need to be recognized and applied. Riparian buffers of mature forest retained along streams in managed forest landscapes offer an opportunity to enhance biodiversity across...

  6. Riparian buffer design guidelines for water quality and wildlife habitat functions on agricultural landscapes in the Intermountain West: Appendix C

    Science.gov (United States)

    Susan Buffler

    2008-01-01

    Currently, there is no scientific literature examining appropriate riparian buffer widths for water quality for streams on private agriculturally dominated lands in arid regions of the Intermountain West. The initial step in this research effort was a review of buffer research as documented in the literature in other physiographic regions of the United States. Research...

  7. Tile Drainage Density Reduces Groundwater Travel Times and Compromises Riparian Buffer Effectiveness.

    Science.gov (United States)

    Schilling, Keith E; Wolter, Calvin F; Isenhart, Thomas M; Schultz, Richard C

    2015-11-01

    Strategies to reduce nitrate-nitrogen (nitrate) pollution delivered to streams often seek to increase groundwater residence time to achieve measureable results, yet the effects of tile drainage on residence time have not been well documented. In this study, we used a geographic information system groundwater travel time model to quantify the effects of artificial subsurface drainage on groundwater travel times in the 7443-ha Bear Creek watershed in north-central Iowa. Our objectives were to evaluate how mean groundwater travel times changed with increasing drainage intensity and to assess how tile drainage density reduces groundwater contributions to riparian buffers. Results indicate that mean groundwater travel times are reduced with increasing degrees of tile drainage. Mean groundwater travel times decreased from 5.6 to 1.1 yr, with drainage densities ranging from 0.005 m (7.6 mi) to 0.04 m (62 mi), respectively. Model simulations indicate that mean travel times with tile drainage are more than 150 times faster than those that existed before settlement. With intensive drainage, less than 2% of the groundwater in the basin appears to flow through a perennial stream buffer, thereby reducing the effectiveness of this practice to reduce stream nitrate loads. Hence, strategies, such as reconnecting tile drainage to buffers, are promising because they increase groundwater residence times in tile-drained watersheds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  8. Density management and riparian buffer study in Western Oregon: Phase 1 results, launch of phase 2 [brochure

    Science.gov (United States)

    Rhonda Mazza

    2009-01-01

    Can we expedite the development of late-successional forest conditions by applying thinning treatments to young forest stands? What effect will these thinning treatments have on headwater ecosystems? These broad questions lie at the foundation of the Density Management and Riparian Buffer Study (DMS) of western Oregon.

  9. Quantifying Forested Riparian Buffer Ability to Ameliorate Stream Temperature in a Missouri Ozark Border Stream of the Central U.S

    Science.gov (United States)

    Bulliner, E. A.; Hubbart, J. A.

    2009-12-01

    Riparian buffers play an important role in modulating stream water quality, including temperature. There is a need to better understand riparian form and function to validate and improve contemporary management practices. Further studies are warranted to characterize energy attenuation by forested riparian canopy layers that normally buffer stream temperature, particularly in the central hardwood forest regions of the United States where relationships between canopy density and stream temperature are unknown. To quantify these complex processes, two intensively instrumented hydroclimate stations were installed along two stream reaches of a riparian stream in central Missouri, USA in the winter of 2008. Hydroclimate stations are located along stream reaches oriented in both cardinal directions, which will allow interpolation of results to other orientations. Each station consists of an array of instrumentation that senses the flux of water and energy into and out of the riparian zone. Reference data are supplied from a nearby flux tower (US DOE) located on top of a forested ridge. The study sites are located within a University of Missouri preserved wildland area on the border of the southern Missouri’s Ozark region, an ecologically distinct region in the central United States. Limestone underlies the study area, resulting in a distinct semi-Karst hydrologic system. Vegetation forms a complex, multi-layered canopy extending from the stream edge through the riparian zone and into surrounding hills. Climate is classified as humid continental, with approximate average annual temperature and precipitation of 13.2°C and 970mm, respectively. Preliminary results (summer 2009 data) indicate incoming short-wave radiation is 24.9% higher at the N-S oriented stream reach relative to the E-W oriented reach. Maximum incoming short wave radiation during the period was 64.5% lower at the N-S reach relative to E-W reach. Average air temperature for the E-W reach was 0.3°C lower

  10. REMM: The Riparian Ecosystem Management Model

    Energy Technology Data Exchange (ETDEWEB)

    Lowrance, R.; Altier, L.S.; Williams, R.G.; Inamdar, S.P.; Sheridan, J.M.; Bosch, D.D.; Hubbard, R.K.; Thomas, D.L.

    2000-03-01

    Riparian buffer zones are effective in mitigating nonpoint source pollution and have been recommended as a best management practice (BMP). The Riparian Ecosystem Management Model (REMM) has been developed for researchers and natural resource agencies as a modeling tool that can help quantify the water quality benefits of riparian buffers under varying site conditions. Processes simulated in REMM include surface and subsurface hydrology; sediment transport and deposition; carbon, nitrogen, and phosphorus transport, removal, and cycling; and vegetation growth. Management options, such as vegetation type, size of the buffer zone, and biomass harvesting also can be simulated. REMM can be used in conjunction with upland models, empirical data, or estimated loadings to examine scenarios of buffer zone design for a hillslope. Evaluation of REMM simulations with field observations shows generally good agreement between simulated and observed data for groundwater nitrate concentrations and water table depths in a mature riparian forest buffer. Sensitivity analysis showed that changes that influenced the water balance or soil moisture storage affected the streamflow output. Parameter changes that influence either hydrology or rates of nutrient cycling affected total N transport and plant N uptake.

  11. Riparian buffer zones on selected rivers in Lower Silesia - an important conservation practice and the management strategy in urban planning

    Science.gov (United States)

    Adamska, Maryna

    2013-09-01

    Buffer zones are narrow strips of land lying along the surface water, covered with appropriately selected vegetation. They separate aquatic ecosystems from the direct impact of agricultural land and reduce the movement of nutrients in the environment. In 2008 the European Commission established requirements for the implementation of buffer strips along water courses. Poland committed to the enforcement of these requirements until 1 January 2012. This was one of the reasons of this study. The subject of the analysis included the following rivers in Lower Silesia: Smortawa, Krynka, Czarna Woda and the selected transects of Ślęza and Nysa Łużycka. Detailed studies were designed to estimate the buffer zones occurring on these watercourses and assess these zones’ structure. This will be used to develop clear criteria for the selection of the width of these zones based on land use land management. It can be used in the implementation of executive acts at different levels of space management. Field research consisted of inventory the extent of riparian buffer strips on selected water courses and photographic documentation. Species composition of the vegetation forming a buffer zone was identified by using Braun-Blanquet method. There was lack of continuity of the riparian buffer zones on investigated rivers. Buffer zones should have carefully formulated definition and width because they are element of the significant ecological value, they perform important environmental protective functions and they are also the subject of Community law.

  12. Heed the head: buffer benefits along headwater streams

    Science.gov (United States)

    Rhonda Mazza; Deanna (Dede) Olson

    2015-01-01

    Since the Northwest Forest Plan implemented riparian buffers along non-fish bearing streams in 1994, there have been questions about how wide those buffers need to be to protect aquatic and riparian resources from upland forest management activities. The Density Management and Riparian Buffer Study of western Oregon, also initiated in 1994, examines the effects of...

  13. Influence of Vegetation Structure on Lidar-derived Canopy Height and Fractional Cover in Forested Riparian Buffers During Leaf-Off and Leaf-On Conditions

    Science.gov (United States)

    Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

    2013-01-01

    Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available. PMID:23382966

  14. Improving Water Quality With Conservation Buffers

    Science.gov (United States)

    Lowrance, R.; Dabney, S.; Schultz, R.

    2003-12-01

    Conservation buffer technologies are new approaches that need wider application. In-field buffer practices work best when used in combination with other buffer types and other conservation practices. Vegetative barriers may be used in combination with edge-of-field buffers to protect and improve their function and longevity by dispersing runoff and encouraging sediment deposition upslope of the buffer. It's important to understand how buffers can be managed to help reduce nutrient transport potential for high loading of nutrients from manure land application sites, A restored riparian wetland buffer retained or removed at least 59 percent of the nitrogen and 66 percent of the phosphorus that entered from an adjacent manure land application site. The Bear Creek National Restoration Demonstration Watershed project in Iowa has been the site of riparian forest buffers and filter strips creation; constructed wetlands to capture tile flow; stream-bank bioengineering; in-stream structures; and controlling livestock grazing. We need field studies that test various widths of buffers of different plant community compositions for their efficacy in trapping surface runoff, reducing nonpoint source pollutants in subsurface waters, and enhancing the aquatic ecosystem. Research is needed to evaluate the impact of different riparian grazing strategies on channel morphology, water quality, and the fate of livestock-associated pathogens and antibiotics. Integrating riparian buffers and other conservation buffers into these models is a key objective in future model development.

  15. Hydrogeologic controls on the transport and fate of nitrate in ground water beneath riparian buffer zones: Results from thirteen studies across the United States

    Science.gov (United States)

    Puckett, L.J.

    2004-01-01

    During the last two decades there has been growing interest in the capacity of riparian buffer zones to remove nitrate from ground waters moving through them. Riparian zone sediments often contain organic carbon, which favors formation of reducing conditions that can lead to removal of nitrate through denitrification. Over the past decade the National Water Quality Assessment (NAWQA) Program has investigated the transport and fate of nitrate in ground and surface waters in study areas across the United States. In these studies riparian zone efficiency in removing nitrate varied widely as a result of variations in hydrogeologic factors. These factors include (1) denitrification in the up-gradient aquifer due to the presence of organic carbon or other electron donors, (2) long residence times (>50 years) along ground-water flow paths allowing even slow reactions to completely remove nitrate, (3) dilution of nitrate enriched waters with older water having little nitrate, (4) bypassing of riparian zones due to extensive use of drains and ditches, and (5) movement of ground water along deep flow paths below reducing zones. By developing a better understanding of the hydrogeologic settings in which riparian buffer zones are likely to be inefficient we can develop improved nutrient management plans. ?? US Government 2004.

  16. Riparian Inventory

    Data.gov (United States)

    Kansas Data Access and Support Center — This dataset is a digital representation of the 1:24,000 Land Use Riparian Areas Inventory for the state of Kansas. The dataset includes a 100 foot buffer around all...

  17. Riparian vegetation structure under desertification scenarios

    Science.gov (United States)

    Rosário Fernandes, M.; Segurado, Pedro; Jauch, Eduardo; Ferreira, M. Teresa

    2015-04-01

    Riparian areas are responsible for many ecological and ecosystems services, including the filtering function, that are considered crucial to the preservation of water quality and social benefits. The main goal of this study is to quantify and understand the riparian variability under desertification scenario(s) and identify the optimal riparian indicators for water scarcity and droughts (WS&D), henceforth improving river basin management. This study was performed in the Iberian Tâmega basin, using riparian woody patches, mapped by visual interpretation on Google Earth imagery, along 130 Sampling Units of 250 m long river stretches. Eight riparian structural indicators, related with lateral dimension, weighted area and shape complexity of riparian patches were calculated using Patch Analyst extension for ArcGis 10. A set of 29 hydrological, climatic, and hydrogeomorphological variables were computed, by a water modelling system (MOHID), using monthly meteorological data between 2008 and 2014. Land-use classes were also calculated, in a 250m-buffer surrounding each sampling unit, using a classification based system on Corine Land Cover. Boosted Regression Trees identified Mean-width (MW) as the optimal riparian indicator for water scarcity and drought, followed by the Weighted Class Area (WCA) (classification accuracy =0.79 and 0.69 respectively). Average Flow and Strahler number were consistently selected, by all boosted models, as the most important explanatory variables. However, a combined effect of hidrogeomorphology and land-use can explain the high variability found in the riparian width mainly in Tâmega tributaries. Riparian patches are larger towards Tâmega river mouth although with lower shape complexity, probably related with more continuous and almost monospecific stands. Climatic, hydrological and land use scenarios, singly and combined, were used to quantify the riparian variability responding to these changes, and to assess the loss of riparian

  18. The StreamCat Dataset: Accumulated Attributes for NHDPlusV2(Version 2.1) Catchments Riparian Buffer for the Conterminous United States: 2010 US Census Road Density

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset represents the road density within individual, local NHDPlusV2 catchments and upstream, contributing watersheds riparian buffers. Attributes of the...

  19. Surface Water Protection by Productive Buffers

    DEFF Research Database (Denmark)

    Christen, Benjamin

    Vegetated riparian buffer zones are a widely recommended best management practice in agriculture for protecting surface and coastal waters from diffuse nutrient pollution. On the background of the EU funded research project NitroEurope (NEU; www.NitroEurope.eu), this study concentrates...... on the mitigation of nitrogen pollution in surface and groundwater, using riparian buffer zones for biomass production. The objectives are to map suitable areas for buffer implementation across the six NEU study landscapes, model tentative N-loss mitigation, calculate biomass production potential and economic...... designed for local conditions could be a way of protecting water quality attractive to many stakeholders....

  20. The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 Catchments Riparian Buffer (Version 2.1) for the Conterminous United States: Wildland Fire Perimeters By Year 2000 - 2010

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset represents the historical fire perimeters within individual local NHDPlusV2 catchments and upstream, contributing watersheds riparian buffers based on...

  1. The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 (Version 2.1) Catchments Riparian Buffer for the Conterminous United States: 2010 US Census Housing Unit and Population Density

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset represents the population and housing unit density within individual, local NHDPlusV2 catchments and upstream, contributing watersheds riparian buffers...

  2. Phytostabilization of metals by indigenous riparian vegetation ...

    African Journals Online (AJOL)

    When measured against an ideal hypothetical buffer zone, the buffer zones under investigation varied between intact and severely compromised. Intact riparian zones showed elevated metal concentrations in the soil, yet significantly lower concentrations in the river water compared to areas with insufficient vegetative cover ...

  3. Biomass and volume yield after 6 years in multiclonal hybrid poplar riparian buffer strips

    Energy Technology Data Exchange (ETDEWEB)

    Fortier, Julien [Centre d' etude de la foret (CEF), Universite du Quebec a Montreal, C.P. 8888, succursale Centre-ville, Montreal, Quebec (Canada); Institut des sciences de l' environnement, Universite du Quebec a Montreal, C.P. 8888, succursale Centre-ville, Montreal, Quebec (Canada); Gagnon, Daniel [Centre d' etude de la foret (CEF), Universite du Quebec a Montreal, C.P. 8888, succursale Centre-ville, Montreal, Quebec (Canada); Institut des sciences de l' environnement, Universite du Quebec a Montreal, C.P. 8888, succursale Centre-ville, Montreal, Quebec (Canada); Fiducie de recherche sur la foret des Cantons-de-l' Est, 1 rue Principale, St-Benoit-du-Lac, Quebec (Canada); Truax, Benoit; Lambert, France [Fiducie de recherche sur la foret des Cantons-de-l' Est, 1 rue Principale, St-Benoit-du-Lac, Quebec (Canada)

    2010-07-15

    In this paper the potential of five hybrid poplar clones (Populus spp.) to provide biomass and wood volume in the riparian zone is assessed in four agroecosystems of southern Quebec (Canada). For all variables measured, significant Site effects were detected. Survival, biomass yield and volume yield were highest at the Bromptonville site. After 6 years of growth, total aboveground biomass production (stems + branches + leaves) reached 112.8 tDM/ha and total leafless biomass production (stems + branches) reached 101.1 tDM/ha at this site, while stem wood volume attained 237.5 m{sup 3}/ha. Yields as low as 14.2 tDM/ha for total biomass and 24.8 m{sup 3}/ha for total stem volume were also observed at the Magog site. Highest yields were obtained on the most fertile sites, particularly in terms of NO{sub 3} supply rate. Mean stem volume per tree was highly correlated with NO{sub 3} supply rate in soils (R{sup 2} = 0.58, p < 0.001). Clone effects were also detected for most of the variables measured. Total aboveground biomass and total stem volume production were high for clone 3729 (Populus nigra x P. maximowiczii) (73.1 tDM/ha and 134.2 m{sup 3}/ha), although not statistically different from clone 915311 (P. maximowiczii x P. balsamifera). However, mean whole-tree biomass (including leaves) was significantly higher for clone 3729 (38.8 kgDM/tree). Multifunctional agroforestry systems such as hybrid poplar riparian buffer strips are among the most sustainable ways to produce a high amount of biomass and wood in a short time period, while contributing to alleviate environmental problems such as agricultural non-point source pollution. (author)

  4. Understanding the Science Behind Riparian Forest Buffers: Effects on Plant and Animal Communities

    OpenAIRE

    Klapproth, Julia C.; Johnson, James E. (James Eric), 1952-

    2009-01-01

    Discusses riparian forests' ability to support many species of wildlife and explains that the importance of a particular riparian area for wildlife will depend on the size of the area, adjoining land uses, riparian vegetation, features inside the area, and the wildlife species of interest.

  5. A Review of Effectiveness of Vegetative Buffers on Sediment Trapping in Agricultural Areas

    Science.gov (United States)

    In recent years, there has been growing recognition of the importance of riparian buffers between agricultural fields and waterbodies. Riparian buffers play an important role in mitigating the impacts of land use activities on water quality and aquatic ecosystems. However, eval...

  6. The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 (Version 2.1) Catchments Riparian Buffer for the Conterminous United States: Mine Density Active Mines and Mineral Plants in the US

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset represents the mine density within individual, local NHDPlusV2 catchments and upstream, contributing watersheds riparian buffers based on mine plants...

  7. Effects of riparian zone buffer widths on vegetation diversity in southern Appalachian headwater catchments

    Science.gov (United States)

    Katherine J. Elliott; James M. Vose

    2016-01-01

    In mountainous areas such as the southern Appalachians USA, riparian zones are difficult to define. Vegetation is a commonly used riparian indicator and plays a key role in protecting water resources, but adequate knowledge of floristic responses to riparian disturbances is lacking. Our objective was to quantify changes in stand-level floristic diversity of...

  8. Initial riparian down wood dynamics in relation to thinning and buffer width

    Science.gov (United States)

    Paul D. Anderson; Deanna H. Olson; Adrian. Ares

    2013-01-01

    Down wood plays many functional roles in aquatic and riparian ecosystems. Simplifi cation of forest structure and low abundance of down wood in stream channels and riparian areas is a common legacy of historical management in headwater forests west of the Cascade Range in the US northwest. Contemporary management practices emphasize the implementation of vegetation...

  9. Benefits of riparian forest for the aquatic ecosystem assessed at a large geographic scale

    Directory of Open Access Journals (Sweden)

    Van Looy K.

    2013-04-01

    Full Text Available Claimed benefits of riparian forest cover for the aquatic ecosystem include purification, thermal control, organic matter input and habitat provision, which may improve physicochemical and biotic quality. However, these beneficial effects might be flawed by multiple stressor conditions of intensive agriculture and urbanization in upstream catchments. We examined the relationship between riparian forest cover and physicochemical quality and biotic integrity indices in extensive large scale datasets. Measurements of hydromorphological conditions and riparian forest cover across different buffer widths for 59 × 103 river stretches covering 230 × 103 km of the French river network were coupled with data for physicochemical and biotic variables taken from the national monitoring network. General linear and quantile regression techniques were used to determine responses of physicochemical variables and biological integrity indices for macroinvertebrates and fish to riparian forest cover in selections of intermediate stress for 2nd to 4th order streams. Significant responses to forest cover were found for the nutrient variables and biological indices. According to these responses a 60% riparian forest cover in the 10 m buffer corresponds to good status boundaries for physicochemical and biotic elements. For the 30 m buffer, the observed response suggests that riparian forest coverage of at least 45% corresponds with good ecological status in the aquatic ecosystem. The observed consistent responses indicate significant potential for improving the quality of the aquatic environment by restoring riparian forest. The effects are more substantial in single-stressor environments but remain significant in multi-stressor environments.

  10. Variable Width Riparian Model Enhances Landscape and Watershed Condition

    Science.gov (United States)

    Abood, S. A.; Spencer, L.

    2017-12-01

    Riparian areas are ecotones that represent about 1% of USFS administered landscape and contribute to numerous valuable ecosystem functions such as wildlife habitat, stream water quality and flows, bank stability and protection against erosion, and values related to diversity, aesthetics and recreation. Riparian zones capture the transitional area between terrestrial and aquatic ecosystems with specific vegetation and soil characteristics which provide critical values/functions and are very responsive to changes in land management activities and uses. Two staff areas at the US Forest Service have coordinated on a two phase project to support the National Forests in their planning revision efforts and to address rangeland riparian business needs at the Forest Plan and Allotment Management Plan levels. The first part of the project will include a national fine scale (USGS HUC-12 digits watersheds) inventory of riparian areas on National Forest Service lands in western United States with riparian land cover, utilizing GIS capabilities and open source geospatial data. The second part of the project will include the application of riparian land cover change and assessment based on selected indicators to assess and monitor riparian areas on annual/5-year cycle basis.This approach recognizes the dynamic and transitional nature of riparian areas by accounting for hydrologic, geomorphic and vegetation data as inputs into the delineation process. The results suggest that incorporating functional variable width riparian mapping within watershed management planning can improve riparian protection and restoration. The application of Riparian Buffer Delineation Model (RBDM) approach can provide the agency Watershed Condition Framework (WCF) with observed riparian area condition on an annual basis and on multiple scales. The use of this model to map moderate to low gradient systems of sufficient width in conjunction with an understanding of the influence of distinctive landscape

  11. The influence of connectivity in forest patches, and riparian vegetation width on stream macroinvertebrate fauna

    Directory of Open Access Journals (Sweden)

    IC Valle

    Full Text Available We assessed two dimensions of stream connectivity: longitudinal (between forest patches along the stream and lateral (riparian vegetation, using macroinvertebrate assemblages as bioindicators. Sites representing different land-uses were sampled in a lowland basin that holds a mosaic of protected areas. Land-use analysis, forest successional stages and riparian zone widths were calculated by the GIS analysis. Macroinvertebrate fauna was strongly affected by land-use. We observed a continuous decrease in the number of sensitive species, %Shredders and IBE-IOC biotic index from the upstream protected area to highly deforested sites, increasing again where the stream crosses a Biological Reserve. When analysing buffer strips, we found aquatic fauna responding to land-use alterations beyond the 30 m riparian corridor (60 m and 100 m wide. We discussed the longitudinal connectivity between forest patches and the riparian vegetation buffer strips necessary to hold high macroinvertebrate diversity. We recommend actions for the increase/maintenance of biodiversity in this and other lowland basins.

  12. Abundance of western red-backed salamanders (Plethodon vehiculum) in the Washington Coast Range after headwater stream-buffer manipulation

    Science.gov (United States)

    Randall J. Wilk; Jeffrey D. Ricklefs; Martin G. Raphael

    2014-01-01

    We evaluated the effect of forest riparian alternative tree buffer designs on Western Red-backed Salamanders (Plethodon vehiculum) along headwater stream banks in managed forests of the Washington Coast Range. We used pit trap live removals in early autumn to estimate relative abundances of surface-active salamanders before and after 3 levels of riparian buffer...

  13. Watershed scale assessment of the impact of forested riparian zones on stream water quality

    Science.gov (United States)

    J. A. Webber; K. W. J. Williard; M. R. Whiles; M. L. Stone; J. J. Zaczek; D. K. Davie

    2003-01-01

    Federal and state land management agencies have been promoting forest and grass riparian zones to combat non-point source nutrient and sediment pollution of our nations' waters. The majority of research examining the effectiveness of riparian buffers at reducing nutrient and sediment inputs to streams has been conducted at the field scale. This study took a...

  14. Riparian Sediment Delivery Ratio: Stiff Diagrams and Artifical Neural Networks

    Science.gov (United States)

    Various methods are used to estimate sediment transport through riparian buffers and grass jilters with the sediment delivery ratio having been the most widely applied. The U.S. Forest Service developed a sediment delivery ratio using the stiff diagram and a logistic curve to int...

  15. Plant Growth and Phosphorus Uptake of Three Riparian Grass Species

    Science.gov (United States)

    Riparian buffers can significantly reduce sediment-bound phosphorus (P) entering surface water, but control of dissolved P inputs is more challenging. Because plant roots remove P from soil solution, it follows that plant uptake will reduce dissolved P losses. We evaluated P uptake of smooth bromegr...

  16. Linked in: connecting riparian areas to support forest biodiversity

    Science.gov (United States)

    Marie Oliver; Kelly Burnett; Deanna Olson

    2010-01-01

    Many forest-dwelling species rely on both terrestrial and aquatic habitat for their survival. These species, including rare and little-understood amphibians and arthropods, live in and around headwater streams and disperse overland to neighboring headwater streams. Forest management policies that rely on riparian buffer strips and structurebased management—practices...

  17. Pavement and riparian forest shape the bird community along an urban river corridor

    Directory of Open Access Journals (Sweden)

    Christopher J.W. McClure

    2015-07-01

    Full Text Available Knowledge of habitat use by animals within urban-riparian corridors during the breeding season is important for conservation, yet remains understudied. We examined the bird community along an urban-riparian corridor through metropolitan Boise, Idaho and predicted that occupancy of individual species and species richness would be greater in forested areas than in urbanized areas. We surveyed birds throughout the summers of 2009 and 2010 and quantified the m2 of each cover-type within 50-m, 100-m, and 200-m buffers surrounding each survey location using satellite imagery. Occupancy modeling revealed that eight of 14 species analyzed were positively associated with riparian forest, and no species avoided forest. Species richness was negatively associated with the amount of paved surface within 100 m of a survey site with richness declining by more than two species for every hectare of paved surface. Most associations with cover-types–especially riparian forest–were at ⩾100 m. Therefore, the riparian forest within 100 m of a given site along an urban-riparian corridor should be the most important for maintaining species richness.

  18. Determining effective riparian buffer width for nonnative plant exclusion and habitat enhancement

    Science.gov (United States)

    Gavin Ferris; Vincent D' Amico; Christopher K. Williams

    2012-01-01

    Nonnative plants threaten native biodiversity in landscapes where habitats are fragmented. Unfortunately, in developed areas, much of the remaining forested habitat occurs in fragmented riparian corridors. Because forested corridors of sufficient width may allow forest interior specializing native species to retain competitive advantage over edge specialist and...

  19. Variable density management in riparian reserves: lessons learned from an operational study in managed forests of western Oregon, USA.

    Science.gov (United States)

    Samuel Chan; Paul Anderson; John Cissel; Larry Lateen; Charley Thompson

    2004-01-01

    A large-scale operational study has been undertaken to investigate variable density management in conjunction with riparian buffers as a means to accelerate development of late-seral habitat, facilitate rare species management, and maintain riparian functions in 40-70 year-old headwater forests in western Oregon, USA. Upland variable retention treatments include...

  20. Effects of groundwater-flow paths on nitrate concentrations across two riparian forest corridors

    Science.gov (United States)

    Speiran, Gary K.

    2010-01-01

    Groundwater levels, apparent age, and chemistry from field sites and groundwater-flow modeling of hypothetical aquifers collectively indicate that groundwater-flow paths contribute to differences in nitrate concentrations across riparian corridors. At sites in Virginia (one coastal and one Piedmont), lowland forested wetlands separate upland fields from nearby surface waters (an estuary and a stream). At the coastal site, nitrate concentrations near the water table decreased from more than 10 mg/L beneath fields to 2 mg/L beneath a riparian forest buffer because recharge through the buffer forced water with concentrations greater than 5 mg/L to flow deeper beneath the buffer. Diurnal changes in groundwater levels up to 0.25 meters at the coastal site reflect flow from the water table into unsaturated soil where roots remove water and nitrate dissolved in it. Decreases in aquifer thickness caused by declines in the water table and decreases in horizontal hydraulic gradients from the uplands to the wetlands indicate that more than 95% of the groundwater discharged to the wetlands. Such discharge through organic soil can reduce nitrate concentrations by denitrification. Model simulations are consistent with field results, showing downward flow approaching toe slopes and surface waters to which groundwater discharges. These effects show the importance of buffer placement over use of fixed-width, streamside buffers to control nitrate concentrations.

  1. Nitrogen removal and microbial communities in a three-stage system simulating a riparian environment.

    Science.gov (United States)

    Wang, Ziyuan; Wang, Zhixin; Pei, Yuansheng

    2014-06-01

    The riparian zone is an active interface for nitrogen removal, in which nitrogen transformations by microorganisms have not been valued. In this study, a three-stage system was constructed to simulate the riparian zone environments, and nitrogen removal as well as the microbial community was investigated in this 'engineered riparian system'. The results demonstrated that stage 1 of this system accounted for 41-51 % of total nitrogen removal. Initial ammonium loading and redox potential significantly impacted the nitrogen removal performances. Stages 1 and 2 were both composed of an anoxic/oxic (A/O) zone and an anaerobic column. The A/O zone removed most of the ammonium load (6.8 g/m(2)/day), while the anaerobic column showed a significant nitrate removal rate (11.1 g/m(2)/day). Molecular biological analysis demonstrated that bacterial diversity was high in the A/O zones, where ammonium-oxidizing bacteria and nitrite-oxidizing bacteria accounted for 8.42 and 3.32 % of the bacterial population, respectively. The denitrifying bacteria Acidovorax sp. and the nitrifying bacteria Nitrosospira/Nitrosomonas were the predominant microorganisms in this engineered riparian system. This three-stage system was established to achieve favorable nitrogen removal and the microbial community in the system was also retained. This investigation should deepen our understanding of biological nitrogen removal in engineered riparian zones.

  2. Environmental and Anthropogenic Factors Influencing Salamanders in Riparian Forests: A Review

    Directory of Open Access Journals (Sweden)

    Hannah L. Clipp

    2014-11-01

    Full Text Available Salamanders and riparian forests are intimately interconnected. Salamanders are integral to ecosystem functions, contributing to vertebrate biomass and complex food webs in riparian forests. In turn, these forests are critical ecosystems that perform many environmental services, facilitate high biodiversity and species richness, and provide habitat to salamander populations. Due to the global decline of amphibians, it is important to understand, as thoroughly and holistically as possible, the roles of environmental parameters and the impact of human activities on salamander abundance and diversity in riparian forests. To determine the population responses of salamanders to a variety of environmental factors and anthropogenic activities, we conducted a review of published literature that compared salamander abundance and diversity, and then summarized and synthesized the data into general patterns. We identify stream quality, leaf litter and woody debris, riparian buffer width, and soil characteristics as major environmental factors influencing salamander populations in riparian forests, describe and explain salamander responses to those factors, and discuss the effects of anthropogenic activities such as timber harvest, prescribed fires, urbanization, road construction, and habitat fragmentation. This review can assist land and natural resource managers in anticipating the consequences of human activities and preparing strategic conservation plans.

  3. BUFFER CAPACITY IN HETEROGENEOUS MULTICOMPONENT SYSTEMS. REVIEW

    Directory of Open Access Journals (Sweden)

    Oxana Spinu

    2015-12-01

    Full Text Available The quantitative basis of the theory of buffer properties for two-phase acid-base buffer systems and for multicomponent heterogeneous systems has been derived. The analytical equations with respect to all components for diverse multicomponent systems were deduced. It has been established, that the buffer capacities of components are mutually proportional.

  4. Small scale denitrification variability in riparian zones: Results from a high-resolution dataset

    Science.gov (United States)

    Gassen, Niklas; Knöller, Kay; Musolff, Andreas; Popp, Felix; Lüders, Tillmann; Stumpp, Christine

    2017-04-01

    Riparian zones are important compartments at the interface between groundwater and surface water where biogeochemical processes like denitrification are often enhanced. Nitrate loads of either groundwater entering a stream through the riparian zone or streamwater infiltrating into the riparian zone can be substantially reduced. These processes are spatially and temporally highly variable, making it difficult to capture solute variabilities, estimate realistic turnover rates and thus to quantify integral mass removal. A crucial step towards a more detailed characterization is to monitor solutes on a scale which adequately resemble the highly heterogeneous distribution and on a scale where processes occur. We measured biogeochemical parameters in a spatial high resolution within a riparian corridor of a German lowland river system over the course of one year. Samples were taken from three newly developed high-resolution multi-level wells with a maximum vertical resolution of 5 cm and analyzed for major ions, DOC and N-O isotopes. Sediment derived during installation of the wells was analyzed for specific denitrifying enzymes. Results showed a distinct depth zonation of hydrochemistry within the shallow alluvial aquifer, with a 1 m thick zone just below the water table with lower nitrate concentrations and EC values similar to the nearby river. Conservative parameters were consistent inbetween the three wells, but nitrate was highly variable. In addition, spots with low nitrate concentrations showed isotopic and microbial evidence for higher denitrification activities. The depth zonation was observed throughout the year, with stronger temporal variations of nitrate concentrations just below the water table compared to deeper layers. Nitrate isotopes showed a clear seasonal trend of denitrification activities (high in summer, low in winter). Our dataset gives new insight into river-groundwater exchange processes and shows the highly heterogeneous distribution of

  5. Cascade-pond System Health Assessment Based on Macroinvertebrate Indices and Its Relationship with Impervious Cover and Aquatic Buffer Zone in Urbanized Catchments

    Directory of Open Access Journals (Sweden)

    Zulkarnain Faris

    2017-01-01

    Full Text Available A cascade-pond system consists of six ponds located at Universitas Indonesia Campus, Depok. Its catchment area is dominated by high density urban area with moderate to high imperviousness. Some of riparian buffers surrounds six ponds are also occupied by high imperviousness that may lead some ecohydrological problems i.e. water quality degradation, declining freshwater biodiversity and food web changes. The aim of this study is assessing the current state of cascade-pond system health. The assessment of macroinvertebrate indices is based on SingScore that have been developed by Public Utilities Board of Singapore for macroinvertebrate biotic index. Impervious cover data is obtained from high-resolution imageries and processed using ArcGIS 10.5. Qualitative statistics methods, Chi-squared test describes the relationship of macroinvertebrate indices with catchment area imperviousness and aquatic buffer zone. The health assessment based on macroinvertebrates indices shows that the lower ponds are relatively healthier than the upper one. There is also any significant relationship between macroinvertebrate indices with impervious cover based on chi square test and cross tabulation analysis.

  6. An Application of BLM's Riparian Inventory Procedure to Rangeland Riparian Resources in the Kern and Kaweah River Watersheds

    Science.gov (United States)

    Patricia Gradek; Lawrence Saslaw; Steven Nelson

    1989-01-01

    The Bakersfield District of the Bureau of Land Management conducted an inventory of rangeland riparian systems using a new method developed by a Bureau-wide task force to inventory, monitor and classify riparian areas. Data on vegetation composition were collected for 65 miles of streams and entered into a hierarchical vegetation classification system. Ratings of...

  7. Does tree harvesting in riparian areas increase stream sedimentation and turbidity - world-wide experience relative to Australia.

    Science.gov (United States)

    Neary, D.; Smethurst, P.; Petrone, K.

    2009-04-01

    A typical improved-pasture property in the high-rainfall zone of Australia contains 0.5-2.0 km of waterways per 100 ha. Nationwide, some 25-30 million ha of improved pasture contains about 100,000 km of streams, of which about 75% are currently un-buffered and contributing to soil and water degradation. Farmers and natural resource managers are considering ways to enhance environmental outcomes at farm and catchment scales using stream-side buffers of trees and other perennial vegetation. Benefits of buffers include improved water quality, biodiversity, carbon sequestration and aesthetics. Lack of sound information and funding for establishing and managing buffer zones is hindering wide-scale adoption of this practice. Stream-side areas of farms are generally highly productive (wet and nutrient-rich) and contain a high biodiversity, but they are also high-risk zones for soil and water values and stock safety. Development of options based on a balance between environmental and economic outcomes would potentially promote wider adoption. Australian codes of forest practice currently discourage or prevent harvesting of trees in streamside buffers. These codes were developed exclusively for large-scale native forests and industrial-scale plantations, and were applicable to farm forestry as now required. In countries including USA and Germany trees in stream-side buffers are harvested using Best Management Practices. Trees may grow at a faster rate in riparian zones and provide a commercial return, but the impacts of tree establishment and harvesting on water yield and quality must be evaluated. However, there have been few designed experiments investigating this problem. Australia has recently initiated studies to explore the use of high-value timber species and associated vegetation in riparian zones to improve water quality, particularly suspended sediment. Preliminary information from the Yan Yan Gurt Catchment in Victoria indicate that forested riparian strips can

  8. Legal ecotones: A comparative analysis of riparian policy protection in the Oregon Coast Range, USA.

    Science.gov (United States)

    Boisjolie, Brett A; Santelmann, Mary V; Flitcroft, Rebecca L; Duncan, Sally L

    2017-07-15

    Waterways of the USA are protected under the public trust doctrine, placing responsibility on the state to safeguard public resources for the benefit of current and future generations. This responsibility has led to the development of management standards for lands adjacent to streams. In the state of Oregon, policy protection for riparian areas varies by ownership (e.g., federal, state, or private), land use (e.g., forest, agriculture, rural residential, or urban) and stream attributes, creating varying standards for riparian land-management practices along the stream corridor. Here, we compare state and federal riparian land-management standards in four major policies that apply to private and public lands in the Oregon Coast Range. We use a standard template to categorize elements of policy protection: (1) the regulatory approach, (2) policy goals, (3) stream attributes, and (4) management standards. All four policies have similar goals for achieving water-quality standards, but differ in their regulatory approach. Plans for agricultural lands rely on outcome-based standards to treat pollution, in contrast with the prescriptive policy approaches for federal, state, and private forest lands, which set specific standards with the intent of preventing pollution. Policies also differ regarding the stream attributes considered when specifying management standards. Across all policies, 25 categories of unique standards are identified. Buffer widths vary from 0 to ∼152 m, with no buffer requirements for streams in agricultural areas or small, non-fish-bearing, seasonal streams on private forest land; narrow buffer requirements for small, non-fish-bearing perennial streams on private forest land (3 m); and the widest buffer requirements for fish-bearing streams on federal land (two site-potential tree-heights, up to an estimated 152 m). Results provide insight into how ecosystem concerns are addressed by variable policy approaches in multi-ownership landscapes, an

  9. Rocky Mountain Riparian Digest

    Science.gov (United States)

    Deborah M. Finch

    2008-01-01

    The Rocky Mountain Riparian Digest presents the many facets of riparian research at the station. Included are articles about protecting the riparian habitat, the social and economic values of riparian environments, watershed restoration, remote sensing tools, and getting kids interested in the science.

  10. Nitrate removal in a restored riparian groundwater system: functioning and importance of individual riparian zones

    Directory of Open Access Journals (Sweden)

    S. Peter

    2012-11-01

    Full Text Available For the design and the assessment of river restoration projects, it is important to know to what extent the elimination of reactive nitrogen (N can be improved in the riparian groundwater. We investigated the effectiveness of different riparian zones, characterized by a riparian vegetation succession, for nitrate (NO3− removal from infiltrating river water in a restored and a still channelized section of the river Thur, Switzerland. Functional genes of denitrification (nirS and nosZ were relatively abundant in groundwater from willow bush and mixed forest dominated zones, where oxygen concentrations remained low compared to the main channel and other riparian zones. After flood events, a substantial decline in NO3− concentration (> 50% was observed in the willow bush zone but not in the other riparian zones closer to the river. In addition, the characteristic enrichment of 15N and 18O in the residual NO3− pool (by up to 22‰ for δ15N and up to 12‰ for δ18O provides qualitative evidence that the willow bush and forest zones were sites of active denitrification and, to a lesser extent, NO3− removal by plant uptake. Particularly in the willow bush zone during a period of water table elevation after a flooding event, substantial input of organic carbon into the groundwater occurred, thereby fostering post-flood denitrification activity that reduced NO3− concentration with a rate of ~21 μmol N l−1 d−1. Nitrogen removal in the forest zone was not sensitive to flood pulses, and overall NO3− removal rates were lower (~6 μmol l−1 d−1. Hence, discharge-modulated vegetation–soil–groundwater coupling was found to be a key driver for riparian NO3− removal. We estimated that

  11. Final Report for File System Support for Burst Buffers on HPC Systems

    Energy Technology Data Exchange (ETDEWEB)

    Yu, W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Mohror, K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-11-27

    Distributed burst buffers are a promising storage architecture for handling I/O workloads for exascale computing. As they are being deployed on more supercomputers, a file system that efficiently manages these burst buffers for fast I/O operations carries great consequence. Over the past year, FSU team has undertaken several efforts to design, prototype and evaluate distributed file systems for burst buffers on HPC systems. These include MetaKV: a Key-Value Store for Metadata Management of Distributed Burst Buffers, a user-level file system with multiple backends, and a specialized file system for large datasets of deep neural networks. Our progress for these respective efforts are elaborated further in this report.

  12. The riparian ecosystem management study: response of small mammals to streamside buffers in western Washington

    Science.gov (United States)

    Martin G. Raphael; Randall J. Wilk

    2013-01-01

    One of the fundamental concepts behind the conservation strategy in the U.S. federal Northwest Forest Plan is the importance of habitat buff ers in providing functional stream and streamside ecosystems. To better understand the importance of riparian buff ers in providing habitat for associated organisms, we investigated responses of small mammals to various streamside...

  13. Riparian zone hydrology and biogeochemistry as a function of stream evolution stage in glaciated landscapes of the US Northeast

    Science.gov (United States)

    Rook, S. P.; Vidon, P.; Walter, M. T.

    2011-12-01

    The management of riparian buffer strips is often regarded as one of the most economical and sustainable methods of managing non-point source pollution and water quality. However, current riparian management often follows a 'one size fits all' design, which fails to recognize the complexity of the many biogeochemical processes that regulate pollutant transformation and retention in these systems. This study addresses two critical gaps in knowledge: (1) How carbon, nitrogen, phosphorous, and iron cycles interact with one another (rather than individually). (2) How stream channel geometry and evolution regulate these nutrient cycles and greenhouse gas (GHG) dynamics in the near stream zone. This project specifically explores the hydrological and biogeochemical functioning of riparian zones across a gradient of stream meander evolution stages, with the primary goal of understanding and predicting potential interactions between nutrient dynamics in these systems. Key research questions include: (1) How does stream meander curvature affect riparian zone hydrology? (2) How does stream meander curvature influence riparian zone biogeochemistry? (3) What relationships exist among N, P, Fe, and GHG dynamics? We instrumented three riparian sites near Ithaca, NY, with a dense network of wells, piezometers, and static chambers. These sites represent three riparian zones along three evolution stages of stream meanders: an inner meander, a straight stream section, and an outer bend of the stream with an oxbow lake formation. In spring through fall 2011, water samples and gas samples were collected at a tri-weekly bases at each of the three sites. Water samples were analyzed for oxidation-reduction potential, dissolved oxygen, temperature, FeII/FeIII, nutrients (NO3-, NH4+, PO43-) and dissolved organic carbon (DOC). GHG fluxes at the soil-atmosphere interface were measured for N2O, CO2, and CH4 gases. We predict that stream curvature will significantly affect groundwater flow

  14. Dynamic Buffer Capacity in Acid-Base Systems.

    Science.gov (United States)

    Michałowska-Kaczmarczyk, Anna M; Michałowski, Tadeusz

    The generalized concept of 'dynamic' buffer capacity β V is related to electrolytic systems of different complexity where acid-base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton-Robinson buffers, taken as examples.

  15. Dynamic Buffer Capacity in Acid?Base Systems

    OpenAIRE

    Micha?owska-Kaczmarczyk, Anna M.; Micha?owski, Tadeusz

    2015-01-01

    The generalized concept of ?dynamic? buffer capacity ? V is related to electrolytic systems of different complexity where acid?base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton?Robinson buffers, taken as examples.

  16. Evaluating the quality of riparian forest vegetation: the Riparian Forest Evaluation (RFV index

    Directory of Open Access Journals (Sweden)

    Fernando Magdaleno

    2014-08-01

    Full Text Available Aim of study: This paper presents a novel index, the Riparian Forest Evaluation (RFV index, for assessing the ecological condition of riparian forests. The status of riparian ecosystems has global importance due to the ecological and social benefits and services they provide. The initiation of the European Water Framework Directive (2000/60/CE requires the assessment of the hydromorphological quality of natural channels. The Directive describes riparian forests as one of the fundamental components that determine the structure of riverine areas. The RFV index was developed to meet the aim of the Directive and to complement the existing methodologies for the evaluation of riparian forests.Area of study: The RFV index was applied to a wide range of streams and rivers (170 water bodies inSpain.Materials and methods: The calculation of the RFV index is based on the assessment of both the spatial continuity of the forest (in its three core dimensions: longitudinal, transversal and vertical and the regeneration capacity of the forest, in a sampling area related to the river hydromorphological pattern. This index enables an evaluation of the quality and degree of alteration of riparian forests. In addition, it helps to determine the scenarios that are necessary to improve the status of riparian forests and to develop processes for restoring their structure and composition.Main results: The results were compared with some previous tools for the assessment of riparian vegetation. The RFV index got the highest average scores in the basins of northernSpain, which suffer lower human influence. The forests in central and southern rivers got worse scores. The bigger differences with other tools were found in complex and partially altered streams and rivers.Research highlights: The study showed the index’s applicability under diverse hydromorphological and ecological conditions and the main advantages of its application. The utilization of the index allows a

  17. Buffer provisioning for large-scale data-acquisition systems

    CERN Document Server

    AUTHOR|(SzGeCERN)756497; The ATLAS collaboration; Garcia Garcia, Pedro Javier; Froening, Holger; Vandelli, Wainer

    2018-01-01

    The data acquisition system of the ATLAS experiment, a major experiment of the Large Hadron Collider (LHC) at CERN, will go through a major upgrade in the next decade. The upgrade is driven by experimental physics requirements, calling for increased data rates on the order of 6~TB/s. By contrast, the data rate of the existing system is 160~GB/s. Among the changes in the upgraded system will be a very large buffer with a projected size on the order of 70 PB. The buffer role will be decoupling of data production from on-line data processing, storing data for periods of up to 24~hours until it can be analyzed by the event processing system. The larger buffer will allow a new data recording strategy, providing additional margins to handle variable data rates. At the same time it will provide sensible trade-offs between buffering space and on-line processing capabilities. This compromise between two resources will be possible since the data production cycle includes time periods where the experiment will not produ...

  18. Linking stream flow and groundwater to avian habitat in a desert riparian system.

    Science.gov (United States)

    Merritt, David M; Bateman, Heather L

    2012-10-01

    Increasing human populations have resulted in aggressive water development in arid regions. This development typically results in altered stream flow regimes, reduced annual flow volumes, changes in fluvial disturbance regimes, changes in groundwater levels, and subsequent shifts in ecological patterns and processes. Balancing human demands for water with environmental requirements to maintain functioning ecosystems requires quantitative linkages between water in streams and ecosystem attributes. Streams in the Sonoran Desert provide important habitat for vertebrate species, including resident and migratory birds. Habitat structure, food, and nest-building materials, which are concentrated in riparian areas, are provided directly or indirectly by vegetation. We measured riparian vegetation, groundwater and surface water, habitat structure, and bird occurrence along Cherry Creek, a perennial tributary of the Salt River in central Arizona, USA. The purpose of this work was to develop an integrated model of groundwater-vegetation-habitat structure and bird occurrence by: (1) characterizing structural and provisioning attributes of riparian vegetation through developing a bird habitat index (BHI), (2) validating the utility of our BHI through relating it to measured bird community composition, (3) determining the riparian plant species that best explain the variability in BHI, (4) developing predictive models that link important riparian species to fluvial disturbance and groundwater availability along an arid-land stream, and (5) simulating the effects of changes in flow regime and groundwater levels and determining their consequences for riparian bird communities. Riparian forest and shrubland vegetation cover types were correctly classified in 83% of observations as a function of fluvial disturbance and depth to water table. Groundwater decline and decreased magnitude of fluvial disturbance caused significant shifts in riparian cover types from riparian forest to

  19. Biogeomorphic feedbacks within riparian corridors: the role of positive interactions between riparian plants

    Science.gov (United States)

    Corenblit, Dov; Steiger, Johannes; Till-Bottraud, Irène

    2017-04-01

    storage within the shared constructed niche. During post-establishment, the probability of finding functional natural root grafting between neighbour trees increases, which could represent a biomechanical and physiological advantage for anchorage and nutrient acquisition and exchange. These stands remain dense on alluvial bars until a threshold of landform construction and hydrogeomorphic disconnection is reached. We suggest that intra-specific competition for resources then increases and induces a density reduction in the stand (i.e. self-thinning), linked not only to competition but potentially also to altruism. This may be due to a grafted root system and the death of aboveground stems of some of the grafted individuals, resulting in more space for the development of the tall competitive individuals, whereas the initial riparian biogeomorphic landform turns more and more into a terrestrial biogeomorphic landform.

  20. Agarose electrophoresis of DNA in discontinuous buffers, using a horizontal slab apparatus and a buffer system with improved properties.

    Science.gov (United States)

    Zsolnai, A; Orbán, L; Chrambach, A

    1993-03-01

    Using a horizontal slab apparatus with a buffer in the reservoirs at the level of the gel ("sea-level electrophoresis"), the retrograde discontinuous buffer system reported by Wiltfang et al. for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of proteins was applied to DNA electrophoresis. This application yielded the advantages of an increased displacement rate of the moving boundary front and a decrease in the concentration of the counterion base in the resolving phase, which yielded reduced relative mobility values at equivalent gel concentrations and practicable low buffer concentrations. The change of relative mobilities (Rf) with a variation of field strength is decreased compared to that of the migration rate in the continuous Tris-boric-acid-EDTA (TBE) buffer and thus the robustness of the system is improved, as well as the efficiency of separation. The system of Wiltfang et al. has in common with previously described discontinuous DNA system, that it is able to stack DNA from dilute samples and is insensitive to sample components with lower net mobilities than DNA, such as acetate. However, the variance of Rf at constant current density in the discontinuous buffer system is not improved over that of the migration rate at constant field strength in the continuous TBE buffer.

  1. The intertwining paths of the density managment and riparian buffer study and the Northwest Forest Plan

    Science.gov (United States)

    Kenneth J. Ruzicka; Deanna H. Olson; Klaus J. Puettmann

    2013-01-01

    Initiated simultaneously, the Density Management and Riparian Buff er Study of western Oregon and the Northwest Forest Plan have had intertwining paths related to federal forest management and policy changes in the Pacifi c Northwest over the last 15 to 20 years. We briefl y discuss the development of the Northwest Forest Plan and how it changed the way forest policy...

  2. Off-Stream Watering Systems and Partial Barriers as a Strategy to Maximize Cattle Production and Minimize Time Spent in the Riparian Area.

    Science.gov (United States)

    Rawluk, Ashley A; Crow, Gary; Legesse, Getahun; Veira, Douglas M; Bullock, Paul R; González, Luciano A; Dubois, Melanie; Ominski, Kim H

    2014-10-29

    A study was conducted in 2009 at two locations in Manitoba (Killarney and Souris), Canada to determine the impact of off-stream waterers (OSW) with or without natural barriers on (i) amount of time cattle spent in the 10 m buffer created within the riparian area, referred to as the riparian polygon (RP), (ii) watering location (OSW or stream), and (iii) animal performance measured as weight gain. This study was divided into three 28-day periods over the grazing season. At each location, the pasture-which ranged from 21.0 ha to 39.2 ha in size-was divided into three treatments: no OSW nor barriers (1CONT), OSW with barriers along the stream bank to deter cattle from watering at the stream (2BARR), and OSW without barriers (3NOBARR). Cattle in 2BARR spent less time in the RP in Periods 1 (p = 0.0002), 2 (p = 0.1116), and 3 (p natural barriers on deterring cattle from the riparian area between periods and locations may be partly attributable to the environmental conditions present during this field trial as well as difference in pasture size and the ability of the established barriers to deter cattle from using the stream as a water source. Treatment had no significant effect (p > 0.05) on cow and calf weights averaged over the summer period. These results indicate that the presence of an OSW does not create significant differences in animal performance when used in extensive pasture scenarios such as those studied within the present study. Whereas the barriers did not consistently discourage watering at the stream, the results provide some indication of the efficacy of the OSW as well as the natural barriers on deterring cattle from the riparian area.

  3. Protein buffering in model systems and in whole human saliva.

    Directory of Open Access Journals (Sweden)

    Andreas Lamanda

    Full Text Available The aim of this study was to quantify the buffer attributes (value, power, range and optimum of two model systems for whole human resting saliva, the purified proteins from whole human resting saliva and single proteins. Two model systems, the first containing amyloglucosidase and lysozyme, and the second containing amyloglucosidase and alpha-amylase, were shown to provide, in combination with hydrogencarbonate and di-hydrogenphosphate, almost identical buffer attributes as whole human resting saliva. It was further demonstrated that changes in the protein concentration as small as 0.1% may change the buffer value of a buffer solution up to 15 times. Additionally, it was shown that there was a protein concentration change in the same range (0.16% between saliva samples collected at the time periods of 13:00 and others collected at 9:00 am and 17:00. The mode of the protein expression changed between these samples corresponded to the change in basic buffer power and the change of the buffer value at pH 6.7. Finally, SDS Page and Ruthenium II tris (bathophenantroline disulfonate staining unveiled a constant protein expression in all samples except for one 50 kDa protein band. As the change in the expression pattern of that 50 kDa protein band corresponded to the change in basic buffer power and the buffer value at pH 6.7, it was reasonable to conclude that this 50 kDa protein band may contain the protein(s belonging to the protein buffer system of human saliva.

  4. A Comparison of Alternative Strategies for Cost-Effective Water Quality Management in Lakes

    Science.gov (United States)

    Kramer, Daniel Boyd; Polasky, Stephen; Starfield, Anthony; Palik, Brian; Westphal, Lynne; Snyder, Stephanie; Jakes, Pamela; Hudson, Rachel; Gustafson, Eric

    2006-09-01

    Roughly 45% of the assessed lakes in the United States are impaired for one or more reasons. Eutrophication due to excess phosphorus loading is common in many impaired lakes. Various strategies are available to lake residents for addressing declining lake water quality, including septic system upgrades and establishing riparian buffers. This study examines 25 lakes to determine whether septic upgrades or riparian buffers are a more cost-effective strategy to meet a phosphorus reduction target. We find that riparian buffers are the more cost-effective strategy in every case but one. Large transaction costs associated with the negotiation and monitoring of riparian buffers, however, may be prohibiting lake residents from implementing the most cost-effective strategy.

  5. Protocols for Mapping and Characterizing Land Use/Land Cover in Riparian Zones

    National Research Council Canada - National Science Library

    Johnson, Michaela R; Zelt, Ronald B

    2005-01-01

    .... Characterization of riparian systems is critical to a comprehensive understanding of nutrient enrichment effects on stream ecosystems because riparian functions provide an important ecological...

  6. Buffer moisture protection system

    International Nuclear Information System (INIS)

    Ritola, J.; Peura, J.

    2013-11-01

    With the present knowledge, bentonite blocks have to be protected from the air relative humidity and from any moisture leakages in the environment that might cause swelling of the bentonite blocks during the 'open' installation phase before backfilling. The purpose of this work was to design the structural reference solution both for the bottom of the deposition hole and for the buffer moisture protection and dewatering system with their integrated equipment needed in the deposition hole. This report describes the Posiva's reference solution for the buffer moisture protection system and the bottom plate on basis of the demands and functional requirements set by long-term safety. The reference solution with structural details has been developed in research work made 2010-2011. The structural solution of the moisture protection system has not yet been tested in practice. On the bottom of the deposition hole a copper plate which protects the lowest bentonite block from the gathered water is installed straight to machined and even rock surface. The moisture protection sheet made of EPDM rubber is attached to the copper plate with an inflatable seal. The upper part of the moisture protection sheet is fixed to the collar structures of the lid which protects the deposition hole in the disposal tunnel. The main function of the moisture protection sheet is to protect bentonite blocks from the leaking water and from the influence of the air humidity at their installation stage. The leaking water is controlled by the dewatering and alarm system which has been integrated into the moisture protection liner. (orig.)

  7. A Study on Afforestation on the Waterside and Its Management

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.Y.; Lee, J.H. [Korea Environment Institute, Seoul (Korea)

    2001-12-01

    The important task of preserving and protecting water quality in water supply areas is best facilitated through environmental-friendly management. systems in adjacent waterzones, particularly through the formation of riparian buffers. Urban areas are of particular interest because their high contributions of pollution loading conflict with their low covering percentage in the watershed. This feature of the urban landscape requires that certain areas to be converted into riparian buffers in order to restrict pollution sources and purify non-point sources. The various functions of the riparian buffer in water supply areas include reducing non-point sources, assuaging the public's peace of mind, and improving the environment's esthetics. To be effective, any damaged riparian buffers in urban areas should be recovered and the existing ones maintained. The following policies are recommended in order to achieve such ends: l. To form operative riparian buffers, designated areas in fixed distances from bodies of water or areas that affect water quality, or absolute protection zones, need to be established. The absolute protecting zone is to be determined by factors of slope, soil, vegetation, pollutant source, and proximity. However, if taking account of flood water levels, surrounding areas within 30m of important water supply areas and urban areas, which are exclusive riparian buffer areas, should also be included. 2. Priority in terms of water quality should be established for each land segment in order to promote efficient land acquisition within the riparian buffer and for nation of vegetation. High priority areas should be dealt with preferentially and environment-friendly land management should be considered. 3. To establish legal bases for waterside zone management, independent laws and amendments to existing laws, such as 'Urban Planning Act' or 'River Act', that are related to the formation of riparian buffers should be introduced

  8. Denitrification controls in urban riparian soils: implications for reducing urban nonpoint source nitrogen pollution.

    Science.gov (United States)

    Li, Yangjie; Chen, Zhenlou; Lou, Huanjie; Wang, Dongqi; Deng, Huanguang; Wang, Chu

    2014-09-01

    The purpose of this research was to thoroughly analyze the influences of environmental factors on denitrification processes in urban riparian soils. Besides, the study was also carried out to identify whether the denitrification processes in urban riparian soils could control nonpoint source nitrogen pollution in urban areas. The denitrification rates (DR) over 1 year were measured using an acetylene inhibition technique during the incubation of intact soil cores from six urban riparian sites, which could be divided into three types according to their vegetation. The soil samples were analyzed to determine the soil organic carbon (SOC), soil total nitrogen (STN), C/N ratio, extractable NO3 (-)-N and NH4 (+)-N, pH value, soil water content (SWC), and the soil nitrification potential to evaluate which of these factors determined the final outcome of denitrification. A nitrate amendment experiment further indicated that the riparian DR was responsive to added nitrate. Although the DRs were very low (0.099 ~ 33.23 ng N2O-N g(-1) h(-1)) due to the small amount of nitrogen moving into the urban riparian zone, the spatial and temporal patterns of denitrification differed significantly. The extractable NO3 (-)-N proved to be the dominant factor influencing the spatial distribution of denitrification, whereas the soil temperature was a determinant of the seasonal DR variation. The six riparian sites could also be divided into two types (a nitrate-abundant and a nitrate-stressed riparian system) according to the soil NO3 (-)-N concentration. The DR in nitrate-abundant riparian systems was significantly higher than that in the nitrate-stressed riparian systems. The DR in riparian zones that were covered with bushes and had adjacent cropland was higher than in grass-covered riparian sites. Furthermore, the riparian DR decreased with soil depth, which was mainly attributed to the concentrated nitrate in surface soils. The DR was not associated with the SOC, STN, C/N ratio, and

  9. Buffer management in wireless full-duplex systems

    KAUST Repository

    Bouacida, Nader

    2015-10-19

    Wireless full-duplex radios can simultaneously transmit and receive using the same frequency. In theory, this can double the throughput. In fact, there is only little work addressing aspects other than throughput gains in full-duplex systems. Over-buffering in today\\'s networks or the so-called “bufferbloat” phenomenon creates excessive end-to-end delays resulting in network performance degradation. Our analysis shows that full-duplex systems may suffer from high latency caused by bloated buffers. In this paper, we address the problem of buffer management in full-duplex networks by using Wireless Queue Management (WQM), which is an active queue management technique for wireless networks. Our solution is based on Relay Full-Duplex MAC (RFD-MAC), an asynchronous media access control protocol designed for relay full-duplexing. We compare the performance of WQM in full-duplex environment to Drop Tail mechanism over various scenarios. Our solution reduces the end-to-end delay by two orders of magnitude while achieving similar throughput in most of the cases.

  10. Modeling phosphorus capture by plants growing in a multi-species riparian buffer

    Science.gov (United States)

    The NST 3.0 mechanistic nutrient uptake model was used to explore phosphorus (P) uptake to a depth of 120 cm over a 126-d growing season in simulated buffer communities composed of mixtures of cottonwood (Populus deltoids Bartr.), switchgrass (Panicum virgatum L.), and smooth brome (Bromis inermis L...

  11. Demographic histories of adaptively diverged riparian and non-riparian species of Ainsliaea (Asteraceae) inferred from coalescent analyses using multiple nuclear loci.

    Science.gov (United States)

    Mitsui, Yuki; Setoguchi, Hiroaki

    2012-12-28

    Understanding demographic histories, such as divergence time, patterns of gene flow, and population size changes, in ecologically diverging lineages provide implications for the process and maintenance of population differentiation by ecological adaptation. This study addressed the demographic histories in two independently derived lineages of flood-resistant riparian plants and their non-riparian relatives [Ainsliaea linearis (riparian) and A. apiculata (non-riparian); A. oblonga (riparian) and A. macroclinidioides (non-riparian); Asteraceae] using an isolation-with-migration (IM) model based on variation at 10 nuclear DNA loci. The highest posterior probabilities of the divergence time parameters were estimated to be ca. 25,000 years ago for A. linearis and A. apiculata and ca. 9000 years ago for A. oblonga and A. macroclinidioides, although the confidence intervals of the parameters had broad ranges. The likelihood ratio tests detected evidence of historical gene flow between both riparian/non-riparian species pairs. The riparian populations showed lower levels of genetic diversity and a significant reduction in effective population sizes compared to the non-riparian populations and their ancestral populations. This study showed the recent origins of flood-resistant riparian plants, which are remarkable examples of plant ecological adaptation. The recent divergence and genetic signatures of historical gene flow among riparian/non-riparian species implied that they underwent morphological and ecological differentiation within short evolutionary timescales and have maintained their species boundaries in the face of gene flow. Comparative analyses of adaptive divergence in two sets of riparian/non-riparian lineages suggested that strong natural selection by flooding had frequently reduced the genetic diversity and size of riparian populations through genetic drift, possibly leading to fixation of adaptive traits in riparian populations. The two sets of riparian/non-riparian

  12. Historic carbon burial spike in an Amazon floodplain lake linked to riparian deforestation near Santarém, Brazil

    Science.gov (United States)

    Sanders, Luciana M.; Taffs, Kathryn; Stokes, Debra; Sanders, Christian J.; Enrich-Prast, Alex; Amora-Nogueira, Leonardo; Marotta, Humberto

    2018-01-01

    Forests along the Amazon Basin produce significant quantities of organic material, a portion of which is deposited in floodplain lakes. Deforestation in the watershed may then have potentially important effects on the carbon fluxes. In this study, a sediment core was extracted from an Amazon floodplain lake to examine the relationship between carbon burial and changing land cover and land use. Historical records from the 1930s and satellite data from the 1970s were used to calculate deforestation rates between 1930 to 1970 and 1970 to 2010 in four zones with different distances from the margins of the lake and its tributaries (100, 500, 1000 and 6000 m buffers). A sediment accumulation rate of ˜ 4 mm yr-1 for the previous ˜ 120 years was determined from the 240+239Pu signatures and the excess 210Pb method. The carbon burial rates ranged between 85 and 298 g C m-2 yr-1, with pulses of high carbon burial in the 1950s, originating from the forest vegetation as indicated by δ13C and δ15N signatures. Our results revealed a potentially important spatial dependence of the organic carbon (OC) burial in Amazon lacustrine sediments in relation to deforestation rates in the catchment. These deforestation rates were more intense in the riparian vegetation (100 m buffer) during the period 1930 to 1970 and the larger open water areas (500, 1000 and 6000 m buffer) during 1970 to 2010. The continued removal of vegetation from the interior of the forest was not related to the peak of OC burial in the lake, but only the riparian deforestation which peaked during the 1950s. Therefore, this supports the conservation priority of riparian forests as an important management practice for Amazon flooded areas. Our findings suggest the importance of abrupt and temporary events in which some of the biomass released by deforestation, especially restricted to areas along open water edges, might reach the depositional environments in the floodplain of the Amazon Basin.

  13. Metal concentrations in urban riparian sediments along an urbanization gradient

    Science.gov (United States)

    Daniel J. Bain; Ian D. Yesilonis; Richard V. Pouyat

    2012-01-01

    Urbanization impacts fluvial systems via a combination of changes in sediment chemistry and basin hydrology. While chemical changes in urban soils have been well characterized, similar surveys of riparian sediments in urbanized areas are rare. Metal concentrations were measured in sediments collected from riparian areas across the urbanization gradient in Baltimore, MD...

  14. River water infiltration enhances denitrification efficiency in riparian groundwater.

    Science.gov (United States)

    Trauth, Nico; Musolff, Andreas; Knöller, Kay; Kaden, Ute S; Keller, Toralf; Werban, Ulrike; Fleckenstein, Jan H

    2018-03-01

    Nitrate contamination in ground- and surface water is a persistent problem in countries with intense agriculture. The transition zone between rivers and their riparian aquifers, where river water and groundwater interact, may play an important role in mediating nitrate exports, as it can facilitate intensive denitrification, which permanently removes nitrate from the aquatic system. However, the in-situ factors controlling riparian denitrification are not fully understood, as they are often strongly linked and their effects superimpose each other. In this study, we present the evaluation of hydrochemical and isotopic data from a 2-year sampling period of river water and groundwater in the riparian zone along a 3rd order river in Central Germany. Based on bi- and multivariate statistics (Spearman's rank correlation and partial least squares regression) we can show, that highest rates for oxygen consumption and denitrification in the riparian aquifer occur where the fraction of infiltrated river water and at the same time groundwater temperature, are high. River discharge and depth to groundwater are additional explanatory variables for those reaction rates, but of minor importance. Our data and analyses suggest that at locations in the riparian aquifer, which show significant river water infiltration, heterotrophic microbial reactions in the riparian zone may be fueled by bioavailable organic carbon derived from the river water. We conclude that interactions between rivers and riparian groundwater are likely to be a key control of nitrate removal and should be considered as a measure to mitigate high nitrate exports from agricultural catchments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Stream-Groundwater Interaction Buffers Seasonal Changes in Urban Stream Water Quality

    Science.gov (United States)

    Ledford, S. H.; Lautz, L. K.

    2013-12-01

    Urban streams in the northeastern United States have large road salt inputs during winter, increased nonpoint sources of inorganic nitrogen, and decreased short-term and permanent storage of nutrients. Meadowbrook Creek, a first order stream in Syracuse, New York, flows along a negative urbanization gradient, from a channelized and armored stream running through the middle of a roadway to a pool-riffle stream meandering through a broad, vegetated floodplain with a riparian aquifer. In this study we investigated how reconnection to groundwater and introduction of riparian vegetation impacted surface water chemistry by making bi-weekly longitudinal surveys of stream water chemistry in the creek from May 2012 until June 2013. Chloride concentrations in the upstream, urban reach of Meadowbrook Creek were strongly influenced by discharge of road salt to the creek during snow melt events in winter and by the chemistry of water draining an upstream retention basin in summer. Chloride concentrations ranged from 161.2 mg/L in August to 2172 mg/L in February. Chloride concentrations in the downstream, 'connected' reach had less temporal variation, ranging from 252.0 mg/L in August to 1049 mg/L in January, and were buffered by groundwater discharge, as the groundwater chloride concentrations during the sampling period ranged from 84.0 to 655.4 mg/L. Groundwater discharge resulted in higher chloride concentrations in summer and lower concentrations in winter in the connected reach relative to the urban reach, minimizing annual variation. In summer, there was little-to-no nitrate in the urban reach due to a combination of limited sources and high primary productivity. In contrast, during the summer, nitrate concentrations reached over 1 mg N/L in the connected reach due to the presence of riparian vegetation and lower nitrate uptake due to cooler temperatures and shading. During the winter, when temperatures fell below freezing, nitrate concentrations in the urban reach

  16. Seasonal change detection of riparian zones with remote sensing images and genetic programming in a semi-arid watershed.

    Science.gov (United States)

    Makkeasorn, Ammarin; Chang, Ni-Bin; Li, Jiahong

    2009-02-01

    Riparian zones are deemed significant due to their interception capability of non-point source impacts and the maintenance of ecosystem integrity region wide. To improve classification and change detection of riparian buffers, this paper developed an evolutionary computational, supervised classification method--the RIparian Classification Algorithm (RICAL)--to conduct the seasonal change detection of riparian zones in a vast semi-arid watershed, South Texas. RICAL uniquely demonstrates an integrative effort to incorporate both vegetation indices and soil moisture images derived from LANDSAT 5 TM and RADARSAT-1 satellite images, respectively. First, an estimation of soil moisture based on RADARSAT-1 Synthetic Aperture Radar (SAR) images was conducted via the first-stage genetic programming (GP) practice. Second, for the statistical analyses and image classification, eight vegetation indices were prepared based on reflectance factors that were calculated as the response of the instrument on LANDSAT. These spectral vegetation indices were then independently used for discriminate analysis along with soil moisture images to classify the riparian zones via the second-stage GP practice. The practical implementation was assessed by a case study in the Choke Canyon Reservoir Watershed (CCRW), South Texas, which is mostly agricultural and range land in a semi-arid coastal environment. To enhance the application potential, a combination of Iterative Self-Organizing Data Analysis Techniques (ISODATA) and maximum likelihood supervised classification was also performed for spectral discrimination and classification of riparian varieties comparatively. Research findings show that the RICAL algorithm may yield around 90% accuracy based on the unseen ground data. But using different vegetation indices would not significantly improve the final quality of the spectral discrimination and classification. Such practices may lead to the formulation of more effective management strategies

  17. Groundwater management institutions to protect riparian habitat

    Science.gov (United States)

    Orr, Patricia; Colby, Bonnie

    2004-12-01

    Groundwater pumping affects riparian habitat when it causes the water table to drop beyond the reach of riparian plants. Riparian habitat provides services that are not directly traded in markets, as is the case with many environmental amenities. There is no direct market where one may buy or sell the mix of services provided by a riparian corridor. The objective of this article is to review groundwater management mechanisms and assess their strengths and weaknesses for preserving the ecological integrity of riparian areas threatened by groundwater pumping. Policy instruments available to those concerned with the effects of groundwater pumping on riparian areas fall into three broad categories: (1) command and control (CAC), (2) incentive-based economic instruments, and (3) cooperative/suasive strategies. The case of the San Pedro River illustrates multiple and overlapping strategies applied in an ongoing attempt to reverse accumulating damage to a riparian ecosystem. Policy makers in the United States can choose among a broad menu of policy options to protect riparian habitat from groundwater pumping. They can capitalize on the clarity of command-and-control strategies, the flexibility and less obtrusive nature of incentive-based economic strategies, and the benefits that collaborative efforts can bring in the form of mutual consideration. While collaborative problem solving and market-based instruments are important policy tools, experience indicates that a well-formulated regulatory structure to limit regional groundwater pumping is an essential component of an effective riparian protection strategy.

  18. Effects of flow regulation and fragmentation by dams on riparian flora in boreal rivers

    International Nuclear Information System (INIS)

    Jansson, Roland

    2000-01-01

    The object of this thesis is to evaluate the effects of river regulation on riparian flora in boreal rivers, and to increase the understanding of the processes causing patterns in species diversity. Comparisons of free-flowing and regulated rivers showed that regulated rivers have fewer plant species and less plant cover per 200-m-stretch of river margin. Regulated river-margins were less species-rich compared to free-flowing rivers irrespective of the type of regulated water level regime, except for unimpounded reaches downstream of dams. Species with good dispersal capacity (wind-dispersed or long-floating species) were least affected by regulation, showing that the ability to recolonize after local extinction is an important character. The temporal development of river-margin vegetation in regulated rivers was studied by investigating differently-old reservoirs and impoundments. Plant-species richness along storage reservoirs increased during the first 30-40 years following damming, but declined thereafter. Both species richness and plant cover remained impoverished compared to free-flowing rivers about 70 years after regulation. Along run-of-river impoundments, plant species richness and cover peaked after 10-20 years. In the long run, riparian species richness was lower, but riparian species density did not differ, compared to free-flowing rivers. Dams fragment the riparian flora. Adjacent run-of-river impoundments developed different riparian floras, probably because dams are barriers to the dispersal of species with poor floating ability. This shows that dams disrupt the ecological continuity not only for the river channel, but also for the adjoining riparian corridor. The number of species and genera were similar between river margins along boreal free-flowing rivers in Europe and North America. The riparian floras shared few species but many genera and families. The regional species pools were similar-sized and composed of species with similar traits, and

  19. A method for quantifying and comparing the costs and benefits of alternative riparian zone buffer widths

    Science.gov (United States)

    Chris B. LeDoux; Ethel Wilkerson

    2008-01-01

    We developed a method that can be used to quantify the opportunity costs and ecological benefits of implementing alternative streamside management zones/buffer zone widths. The opportunity costs are computed based on the net value of the timber left behind in the buffer zone, the stump-to-mill logging costs for the logging technology that would have been used to...

  20. Impacts of Karkheh Dam on Spatial Pattern of Riparian Zones in Karkheh National Park

    Directory of Open Access Journals (Sweden)

    H. Madadi

    2013-03-01

    Full Text Available Effective river ecosystem management requires that the existing hydrologic regime be characterized in terms of the natural hydrologic regime and the degree to which the human-altered regime differs from natural conditions. This is known as Range of Variation Approach (RVA and can be used for variation of stream flow, range of variation and appraisal of dam impacts on riparian zones. In this paper, we used 31 hydrologic parameters, classified into five groups, monthly flow indices, extreme flow indices, timing indices, high-flow and low-flow indices, and rate of change, to assess hydrologic regime alteration in downstream of Karkheh dam. For this, purpose the hydrologic parameters of Pay-Pol hydrometric station have been taken. into consideration. As the Riparian ecosystems are highly dependent on and sensitive to variation in the hydrological cycle, the focus of this study was the 50-meter buffer of the Karkheh River. To examine the impacts caused by the variation of hydrologic regime, we tested if this variation and 8 different landscape metrics in the study area are correlated. The results showed that variation of hydrologic regime had a significant impact on the landscape structure of riparian zone in Karkheh downstream and caused isolation in landscape pattern of the woodland cover. Therefore, landscape structure in Karkheh downstream is highly correlated to hydrologic processes of upstream of the river. It can be concluded that an effective water management strategy is keeping safe the ecological condition and integrity of the riparian zone of Karkheh. This happens when all the hydrologic parameters are in the natural range of variation as they were before dam construction.

  1. Riparian planning in Yogyakarta City

    Science.gov (United States)

    Rachmawati, R.; Prakoso, E.; Sadali, M. I.; Yusuf, M. G.

    2018-04-01

    Riparian is a potential for slums in urban areas. The city of Yogyakarta is passed by three rivers namely Code, Gajahwong, and Winongo, crossing the city. Riparian in the three rivers are potential for slum if the area is not well managed. This paper is based on the survey results of the structured interview with the people living in the riparian area in Yogyakarta City. They were 75 respondents from the three riparian. The result shows that several reasons why people prefer to remain living in the area are limited spaces and high land price in the city as well as inherited from their parents. The facts that there are still several problems related to the condition of settlement environment in the riparian, i.e., The condition of densely-populated areas, limited availability of land, and limited public spaces. Efforts that can be done to solve problems related to the riparian planning are anticipating disasters like flood and landslide, paying attention to densely-populated and unwell-planned areas, and handling garbage that has been abandoned into the river. The program expected by those living along both riversides is intended to give priorities on providing some aid for those whose houses are not in good condition, controlling buildings without a permit, and building a dike along the river. Efficiency can be made by making use of the space adequately between the one for settlement and the other one for open-green space for both aesthetic and economic purposes.

  2. Biomass and carbon pools of disturbed riparian forests

    Science.gov (United States)

    Laura A. B. Giese; W. M. Aust; Randall K. Kolka; Carl C. Trettin

    2003-01-01

    Quantification of carbon pools as affected by forest age/development can facilitate riparian restoration and increase awareness of the potential for forests to sequester global carbon. Riparian forest biomass and carbon pools were quantified for four riparian forests representing different seral stages in the South Carolina Upper Coastal Plain. Three of the riparian...

  3. Theory, methods and tools for determining environmental flows for riparian vegetation: Riparian vegetation-flow response guilds

    Science.gov (United States)

    Merritt, D.M.; Scott, M.L.; Leroy, Poff N.; Auble, G.T.; Lytle, D.A.

    2010-01-01

    Riparian vegetation composition, structure and abundance are governed to a large degree by river flow regime and flow-mediated fluvial processes. Streamflow regime exerts selective pressures on riparian vegetation, resulting in adaptations (trait syndromes) to specific flow attributes. Widespread modification of flow regimes by humans has resulted in extensive alteration of riparian vegetation communities. Some of the negative effects of altered flow regimes on vegetation may be reversed by restoring components of the natural flow regime. 2. Models have been developed that quantitatively relate components of the flow regime to attributes of riparian vegetation at the individual, population and community levels. Predictive models range from simple statistical relationships, to more complex stochastic matrix population models and dynamic simulation models. Of the dozens of predictive models reviewed here, most treat one or a few species, have many simplifying assumptions such as stable channel form, and do not specify the time-scale of response. In many cases, these models are very effective in developing alternative streamflow management plans for specific river reaches or segments but are not directly transferable to other rivers or other regions. 3. A primary goal in riparian ecology is to develop general frameworks for prediction of vegetation response to changing environmental conditions. The development of riparian vegetation-flow response guilds offers a framework for transferring information from rivers where flow standards have been developed to maintain desirable vegetation attributes, to rivers with little or no existing information. 4. We propose to organise riparian plants into non-phylogenetic groupings of species with shared traits that are related to components of hydrologic regime: life history, reproductive strategy, morphology, adaptations to fluvial disturbance and adaptations to water availability. Plants from any river or region may be grouped

  4. Riparian Habitat - Product of 2 riparian habitat workshops

    Data.gov (United States)

    California Natural Resource Agency — In two riparian habitat workshops held between 2001 and 2002, scientists and managers identified the need for determining the scope of a consistent and acceptable...

  5. Historic carbon burial spike in an Amazon floodplain lake linked to riparian deforestation near Santarém, Brazil

    Directory of Open Access Journals (Sweden)

    L. M. Sanders

    2018-01-01

    Full Text Available Forests along the Amazon Basin produce significant quantities of organic material, a portion of which is deposited in floodplain lakes. Deforestation in the watershed may then have potentially important effects on the carbon fluxes. In this study, a sediment core was extracted from an Amazon floodplain lake to examine the relationship between carbon burial and changing land cover and land use. Historical records from the 1930s and satellite data from the 1970s were used to calculate deforestation rates between 1930 to 1970 and 1970 to 2010 in four zones with different distances from the margins of the lake and its tributaries (100, 500, 1000 and 6000 m buffers. A sediment accumulation rate of  ∼ 4 mm yr−1 for the previous  ∼ 120 years was determined from the 240+239Pu signatures and the excess 210Pb method. The carbon burial rates ranged between 85 and 298 g C m−2 yr−1, with pulses of high carbon burial in the 1950s, originating from the forest vegetation as indicated by δ13C and δ15N signatures. Our results revealed a potentially important spatial dependence of the organic carbon (OC burial in Amazon lacustrine sediments in relation to deforestation rates in the catchment. These deforestation rates were more intense in the riparian vegetation (100 m buffer during the period 1930 to 1970 and the larger open water areas (500, 1000 and 6000 m buffer during 1970 to 2010. The continued removal of vegetation from the interior of the forest was not related to the peak of OC burial in the lake, but only the riparian deforestation which peaked during the 1950s. Therefore, this supports the conservation priority of riparian forests as an important management practice for Amazon flooded areas. Our findings suggest the importance of abrupt and temporary events in which some of the biomass released by deforestation, especially restricted to areas along open water edges, might reach the depositional environments in

  6. Efcient Computation of Buffer Capacities for Cyclo-Static Real-Time Systems with Back-Pressure

    NARCIS (Netherlands)

    Wiggers, M.H.; Bekooij, Marco; Bekooij, Marco Jan Gerrit; Jansen, P.G.; Smit, Gerardus Johannes Maria

    2006-01-01

    A key step in the design of cyclo-static real-time systems is the determination of buffer capacities. In our multiprocessor system, we apply back-pressure, which means that tasks wait for space in output buffers. Consequently buffer capacities affect the throughput. This requires the derivation of

  7. Optimal Maintenance of a Production System with Intermediate Buffers

    Directory of Open Access Journals (Sweden)

    Constantinos C. Karamatsoukis

    2012-01-01

    Full Text Available We consider a production-inventory system that consists of an input-generating installation, a production unit and L intermediate buffers. It is assumed that the installation transfers the raw material to buffer and the production unit pulls the raw material from buffer We consider the problem of the optimal preventive maintenance of the installation if the installation deteriorates stochastically with usage and the production unit is always in operative condition. We also consider the problem of the optimal preventive maintenance of the production unit if the production unit deteriorates stochastically with usage and the installation is always in operative condition. Under a suitable cost structure and for given contents of the buffers, it is proved that the average-cost optimal policy for the first (second problem initiates a preventive maintenance of the installation (production unit if and only if the degree of deterioration of the installation (production unit exceeds some critical level. Numerical results are presented for both problems.

  8. Off-Stream Watering Systems and Partial Barriers as a Strategy to Maximize Cattle Production and Minimize Time Spent in the Riparian Area

    Directory of Open Access Journals (Sweden)

    Ashley A. Rawluk

    2014-10-01

    Full Text Available A study was conducted in 2009 at two locations in Manitoba (Killarney and Souris, Canada to determine the impact of off-stream waterers (OSW with or without natural barriers on (i amount of time cattle spent in the 10 m buffer created within the riparian area, referred to as the riparian polygon (RP, (ii watering location (OSW or stream, and (iii animal performance measured as weight gain. This study was divided into three 28-day periods over the grazing season. At each location, the pasture—which ranged from 21.0 ha to 39.2 ha in size—was divided into three treatments: no OSW nor barriers (1CONT, OSW with barriers along the stream bank to deter cattle from watering at the stream (2BARR, and OSW without barriers (3NOBARR. Cattle in 2BARR spent less time in the RP in Periods 1 (p = 0.0002, 2 (p = 0.1116, and 3 (p < 0.0001 at the Killarney site compared to cattle in 3NOBARR at the same site. Cattle in 2BARR at the Souris site spent more time in the RP in Period 1 (p < 0.0001 and less time in Period 2 (p = 0.0002 compared to cattle in 3NOBARR. Cattle did use the OSW, but not exclusively, as watering at the stream was still observed. The observed inconsistency in the effectiveness of the natural barriers on deterring cattle from the riparian area between periods and locations may be partly attributable to the environmental conditions present during this field trial as well as difference in pasture size and the ability of the established barriers to deter cattle from using the stream as a water source. Treatment had no significant effect (p > 0.05 on cow and calf weights averaged over the summer period. These results indicate that the presence of an OSW does not create significant differences in animal performance when used in extensive pasture scenarios such as those studied within the present study. Whereas the barriers did not consistently discourage watering at the stream, the results provide some indication of the efficacy of the OSW as well

  9. Advances on Modelling Riparian Vegetation-Hydromorphology Interactions

    NARCIS (Netherlands)

    Solari, L.; Van Oorschot, M.; Belletti, B.; Hendriks, D.; Rinaldi, M.; Vargas-Luna, A.

    2016-01-01

    Riparian vegetation actively interacts with fluvial systems affecting river hydrodynamics, morphodynamics and groundwater. These interactions can be coupled because both vegetation and hydromorphology (i.e. the combined scientific study of hydrology and fluvial geomorphology) involve dynamic

  10. Down by the riverside: urban riparian ecology

    Science.gov (United States)

    Peter M. Groffman; Daniel J. Bain; Lawrence E. Band; Kenneth T. Belt; Grace S. Brush; J. Morgan Grove; Richard V. Pouyat; Ian C. Yesilonis; Wayne C. Zipperer

    2003-01-01

    Riparian areas are hotspots of interactions between plants, soil, water, microbes, and people. While urban land use change has been shown to have dramatic effects on watershed hydrology, there has been surprisingly little analysis of its effects on riparian areas. Here we examine the ecology of urban riparian zones, focusing on work done in the Baltimore Ecosystem...

  11. Evaluating the ecological economic success of riparian restoration projects in Arizona (Abstract)

    Science.gov (United States)

    Gary B. Snider

    2000-01-01

    The past 4 years the Arizona Water Protection Fund provided more than $25 million to individuals and organizations for stream and riparian restoration projects in Arizona. Information which increases the awareness of the value of Arizona's riparian systems is crucial to the incorporation of ecosystem services into decision-making frameworks, which are largely...

  12. Traveling waves in the discrete fast buffered bistable system.

    Science.gov (United States)

    Tsai, Je-Chiang; Sneyd, James

    2007-11-01

    We study the existence and uniqueness of traveling wave solutions of the discrete buffered bistable equation. Buffered excitable systems are used to model, among other things, the propagation of waves of increased calcium concentration, and discrete models are often used to describe the propagation of such waves across multiple cells. We derive necessary conditions for the existence of waves, and, under some restrictive technical assumptions, we derive sufficient conditions. When the wave exists it is unique and stable.

  13. State-and-transition prototype model of riparian vegetation downstream of Glen Canyon Dam, Arizona

    Science.gov (United States)

    Ralston, Barbara E.; Starfield, Anthony M.; Black, Ronald S.; Van Lonkhuyzen, Robert A.

    2014-01-01

    Facing an altered riparian plant community dominated by nonnative species, resource managers are increasingly interested in understanding how to manage and promote healthy riparian habitats in which native species dominate. For regulated rivers, managing flows is one tool resource managers consider to achieve these goals. Among many factors that can influence riparian community composition, hydrology is a primary forcing variable. Frame-based models, used successfully in grassland systems, provide an opportunity for stakeholders concerned with riparian systems to evaluate potential riparian vegetation responses to alternative flows. Frame-based, state-and-transition models of riparian vegetation for reattachment bars, separation bars, and the channel margin found on the Colorado River downstream of Glen Canyon Dam were constructed using information from the literature. Frame-based models can be simple spreadsheet models (created in Microsoft® Excel) or developed further with programming languages (for example, C-sharp). The models described here include seven community states and five dam operations that cause transitions between states. Each model divides operations into growing (April–September) and non-growing seasons (October–March) and incorporates upper and lower bar models, using stage elevation as a division. The inputs (operations) can be used by stakeholders to evaluate flows that may promote dynamic riparian vegetation states, or identify those flow options that may promote less desirable states (for example, Tamarisk [Tamarix sp.] temporarily flooded shrubland). This prototype model, although simple, can still elicit discussion about operational options and vegetation response.

  14. Critical micelle concentration of surfactants in aqueous buffered and unbuffered systems

    International Nuclear Information System (INIS)

    Fuguet, Elisabet; Rafols, Clara; Roses, Marti; Bosch, Elisabeth

    2005-01-01

    Critical micelle concentration (CMC) of sodium dodecyl sulphate (SDS), lithium perfluorooctanesulfonate (LPFOS), hexadecyltrimethylammonium bromide (HTAB), tetradecyltrimethylammonium bromide (TTAB), and sodium cholate (SC), surfactants commonly used as pseudostationary phases in micellar electrokinetic chromatography (MEKC), have been determined by means of three different methods: MEKC, spectrophotometry, and conductometry. Determinations have been performed in water, and also in different concentrations of phosphate buffer at pH 7.0. CMC values ranging from 8.08 (water) to 1.99 (50 mM phosphate buffer) mM for SDS, from 7.16 (water) to 2,81 (30 mM phosphate buffer) mM for LPFOS, from 3.77 (water) to 1.93 (20 mM phosphate buffer) mM for TTAB, from 0.91 (water) to ∼0.34 (20 mM phosphate buffer) for HTAB, and around 13 mM (20 mM phosphate buffer) for SC, are obtained. The effect of the electrolyte concentration on the CMC, as well as the linear relationship between the electrolyte counter-ion concentration and the CMC are discussed. This linear relationship provides an easy way for users to estimate the CMC of a MEKC system, at a given electrolyte concentration. A comparison between experimental methods, as well as a discussion about the suitability of a given method for the determination of the CMC for a given surfactant system is also provided

  15. Riparian ecotone: A functional definition and delineation for resource assessment

    Science.gov (United States)

    E. S Verry; C. A Dolloff; M. E. Manning

    2004-01-01

    We propose a geomorphic basis for defining riparian areas using the term: riparian ecotone, discuss how past definitions fall short, and illustrate how a linked sequence of definition, delineation, and riparian sampling are used to accurately assess riparian resources on the ground. Our riparian ecotone is based on the width of the valley (its floodprone area width)...

  16. Historical land-cover/use in different slope and riparian buffer zones in watersheds of the state of São Paulo, Brazil Cobertura vegetal em diferentes usos do solo e declividades do terreno em bacias hidrográficas do estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Alexandre Marco da Silva

    2007-08-01

    Full Text Available Information about the land cover of a region it is a key information for several purposes. This paper aimed to elaborate land-cover maps using digital satellite images obtained in 1997 from seven watersheds (Piracicaba, Moji-Guaçu, Alto Paranapanema, Turvo Aguapeí, Peixe, and São José dos Dourados located in the State of São Paulo, southeastern Brazil. Additionaly, this study evaluated the relationship between land-cover and slopes of the terrain of the seven watersheds. A third objective was to estimate the percentage of riparian vegetation currently remaining along the streams in a 30-meter width buffer zone. Three research questions were posed: i What is the dominant land-cover of these watersheds? ii Is the riparian vegetation well preserved in the 30m width buffer zone? If not, iii what is the dominant land-cover in these areas and what would be the cost of recovering such areas? Pasture was the predominant land-cover, occurring in approximately 50% of the entire study area, while sugar cane (Saccharum officinarum (14% constituted the second most frequent land-cover. Approximately 50% of the area of the seven basins is considered flat (40% or smoothly rolling (10%. The terrain only becomes hillier in the Piracicaba and Alto Paranapanema basins, where a little less than 50% have slopes higher than 8%. The total riparian buffer strip zone occupied an area equivalent to approximately 6,200 km². From this total, only 25% is preserved. Pasture is the main land-cover of the riparian buffer strip zone.Informações sobre mudanças no uso e cobertura do solo são fundamentais para vários propósitos sociais, econômicos e ambientais. O principal objetivo deste estudo foi elaborar mapas de cobertura do solo usando imagens digitais obtidas por satélite no ano de 1997 nas seguintes bacias hidrográficas do Estado de São Paulo: Piracicaba, Moji-Guaçu, Alto Paranapanema, Turvo Aguapeí, Peixe, and São José dos Dourados. Adicionalmente, a

  17. Analysis of carbon and nitrogen dynamics in riparian soils: model development.

    Science.gov (United States)

    Brovelli, A; Batlle-Aguilar, J; Barry, D A

    2012-07-01

    The quality of riparian soils and their ability to buffer contaminant releases to aquifers and streams are connected intimately to moisture content and nutrient dynamics, in particular of carbon (C) and nitrogen (N). A multi-compartment model-named the Riparian Soil Model (RSM)-was developed to help investigate the influence and importance of environmental parameters, climatic factors and management practices on soil ecosystem functioning in riparian areas. The model improves existing tools, in particular regarding its capability to simulate a wide range of temporal scales, from days to centuries, along with its ability to predict the concentration and vertical distribution of dissolved organic matter (DOM). It was found that DOM concentration controls the amount of soil organic matter (SOM) stored in the soil as well as the respiration rate. The moisture content was computed using a detailed water budget approach, assuming that within each time step all the water above field capacity drains to the layer underneath, until it becomes fully saturated. A mass balance approach was also used for nutrient transport, whereas the biogeochemical reaction network was developed as an extension of an existing C and N turnover model. Temperature changes across the soil profile were simulated analytically, assuming periodic temperature changes in the topsoil. To verify the consistency of model predictions and to illustrate its capabilities, a synthetic but realistic soil profile in a deciduous forest was simulated. Model parameters were taken from the literature, and model predictions were consistent with experimental observations for a similar scenario. Modelling results stressed the importance of environmental conditions on SOM cycling in soils. The mineral and organic C and N stocks fluctuate at different time scales in response to oscillations in climatic conditions and vegetation inputs/uptake. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Use of bicarbonate buffer systems for dissolution characterization of enteric-coated proton pump inhibitor tablets.

    Science.gov (United States)

    Shibata, Hiroko; Yoshida, Hiroyuki; Izutsu, Ken-Ichi; Goda, Yukihiro

    2016-04-01

    The aim of this study was to assess the effects of buffer systems (bicarbonate or phosphate at different concentrations) on the in vitro dissolution profiles of commercially available enteric-coated tablets. In vitro dissolution tests were conducted using an USP apparatus II on 12 enteric-coated omeprazole and rabeprazole tablets, including innovator and generic formulations in phosphate buffers, bicarbonate buffers and a media modified Hanks (mHanks) buffer. Both omeprazole and rabeprazole tablets showed similar dissolution profiles among products in the compendial phosphate buffer system. However, there were large differences between products in dissolution lag time in mHanks buffer and bicarbonate buffers. All formulations showed longer dissolution lag times at lower concentrations of bicarbonate or phosphate buffers. The dissolution rank order of each formulation differed between mHanks buffer and bicarbonate buffers. A rabeprazole formulation coated with a methacrylic acid copolymer showed the shortest lag time in the high concentration bicarbonate buffer, suggesting varied responses depending on the coating layer and buffer components. Use of multiple dissolution media during in vitro testing, including high concentration bicarbonate buffer, would contribute to the efficient design of enteric-coated drug formulations. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

  19. Carbon stock and turnover in riparian soils under lowland rainforest transformation systems on Sumatra, Indonesia

    Science.gov (United States)

    Hennings, Nina; Kuzyakov, Yakov

    2017-04-01

    In many tropical areas, rainforests are being cleared in order to exploit timber and other forest products as well as plant crops for food, feed and fuel use. The determinants of different patterns of deforestation and the roles of resulting transformation systems of tropical riparian rainforests for ecological functions have yet received little attention in scientific research. Especially C stocks in riparian zones are strongly affected by climate and land use changes that lead to changes in water regime and ground water level drops. We investigated the effects of land transformations in riparian ecosystems of Sumatra, on soil C content, stocks and decomposability at the landscape scale. We compare C losses in transformation systems and rainforests and estimate the contribution of soil erosion and organic matter mineralization. Further, these losses are related to changing water level and temperature increase along increasing distance to the stream. This approach is based on changing δ13C values of SOC in the topsoil as compared to those in subsoil. The shift of δ13C of SOC in the topsoil from the linear regression calculated by δ13C value with log(SOC) in the topsoil represents the modification of the C turnover rate in the top soil. Erosion is estimated by the shift of the δ13C value of SOC in the subsoil under plantations. Further, the δ13C and δ15N soil profiles and their comparison with litter of local vegetation, can be used to estimate the contribution of autochthonous and allochthonous organics to soil C stocks. Preliminary results show strong increase of erosive losses, increased decomposition with land-use transformation and decrease of C stocks with decreasing water table.

  20. BurstMem: A High-Performance Burst Buffer System for Scientific Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Teng [Auburn University, Auburn, Alabama; Oral, H Sarp [ORNL; Wang, Yandong [Auburn University, Auburn, Alabama; Settlemyer, Bradley W [ORNL; Atchley, Scott [ORNL; Yu, Weikuan [Auburn University, Auburn, Alabama

    2014-01-01

    The growth of computing power on large-scale sys- tems requires commensurate high-bandwidth I/O system. Many parallel file systems are designed to provide fast sustainable I/O in response to applications soaring requirements. To meet this need, a novel system is imperative to temporarily buffer the bursty I/O and gradually flush datasets to long-term parallel file systems. In this paper, we introduce the design of BurstMem, a high- performance burst buffer system. BurstMem provides a storage framework with efficient storage and communication manage- ment strategies. Our experiments demonstrate that BurstMem is able to speed up the I/O performance of scientific applications by up to 8.5 on leadership computer systems.

  1. Best management practices for riparian areas

    Science.gov (United States)

    Michael J. Phillips; Lloyd W. Swift; Charles R. Blinn

    2000-01-01

    Forest streams, lakes, and other water bodies create unique conditions along their margins that control and influence transfers of energy, nutrients, and sediments between aquatic and terrestrial systems. These riparian areas are among the most critical features of the landscape because they contain a rich diversity of plants and animals and help to maintain water...

  2. Methods for evaluating riparian habitats with applications to management

    Science.gov (United States)

    Platts, William S.; Armour, C.L.; Booth, G.D.; Bryant, M.; Bufford, J.L.; Cuplin, P.; Jensen, S.; Lienkaemper, G.W.; Minshall, G.W.; Monsen, S.T.; Nelson, R.L.; Sedell, J.R.; Tuhy, J.S.

    1987-01-01

    Riparian area planning and management is a major national issues today--something that should have been the case a century ago. A century of additive effects of land use has resulted in major impacts on many riparian stream habitats and their fisheries, wildlife, and domestic livestock use. Before scientists can evaluate the influences of various land and water uses on riparian environments, they must first understand these environments. This means being able to detect and measure with confidence the natural and artificial variation and instantaneous conditions of the riparian habitat. These conditions must then be related to the production capability of riparian habitat and any extraneous factors affecting this production potential.

  3. Improved Mapping of Riparian Wetlands Using Reach Topography

    Science.gov (United States)

    Riparian wetlands provide a suite of ecosystems services including floodwater retention, biogeochemical processing, and habitat provisioning. However in one mid-Atlantic watershed the National Wetlands Inventory was shown to underrepresent these systems by greater than 50%. These...

  4. Principles for Establishing Ecologically Successful Riparian Corridors

    Science.gov (United States)

    Principles for establishing riparian areas. Riparian areas are three‐dimensional ecotones of interaction that include terrestrial and aquatic ecosystems, that extend down into the groundwater, up above the canopy, outward across the floodplain.

  5. Quantifying the contribution of riparian soils to the provision of ecosystem services.

    Science.gov (United States)

    de Sosa, Laura L; Glanville, Helen C; Marshall, Miles R; Prysor Williams, A; Jones, Davey L

    2018-05-15

    Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a diverse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types; 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils; and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7-17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research

  6. Designing cost efficient buffer zone programs: An application of the FyrisSKZ tool in a Swedish catchment.

    Science.gov (United States)

    Collentine, Dennis; Johnsson, Holger; Larsson, Peter; Markensten, Hampus; Persson, Kristian

    2015-03-01

    Riparian buffer zones are the only measure which has been used extensively in Sweden to reduce phosphorus losses from agricultural land. This paper describes how the FyrisSKZ web tool can be used to evaluate allocation scenarios using data from the Svärta River, an agricultural catchment located in central Sweden. Three scenarios are evaluated: a baseline, a uniform 6-m-wide buffer zone in each sub-catchment, and an allocation of areas of buffer zones to sub-catchments based on the average cost of reduction. The total P reduction increases by 30 % in the second scenario compared to the baseline scenario, and the average reduction per hectare increases by 90 % while total costs of the program fall by 32 %. In the third scenario, the average cost per unit of reduction (163 kg P(-1)) is the lowest of the three scenarios (58 % lower than the baseline) and has the lowest total program costs.

  7. Susceptibility of riparian wetland plants to perfluorooctanoic acid (PFOA) accumulation.

    Science.gov (United States)

    Mudumbi, J B N; Ntwampe, S K O; Muganza, M; Okonkwo, J O

    2014-01-01

    As plants have been shown to accumulate organic compounds from contaminated sediments, there is a potential for long-lasting ecological impact as a result of contaminant accumulation in riparian areas of wetlands, particularly the accumulation of non-biodegradable contaminants such as perfluorooctanoic acid (PFOA). In this study, commonly found riparian wetland plants including reeds, i.e., Xanthium strumarium, Phragmites australis, Schoenoplectus corymbosus, Ruppia maritime; Populus canescens, Polygonum salicifolium, Cyperus congestus; Persicaria amphibian, Ficus carica, Artemisia schmidtiana, Eichhornia crassipes, were studied to determine their susceptibility to PFOA accumulation from PFOA contaminated riparian sediment with a known PFOA concentration, using liquid chromatography/tandem mass spectrometry (LC/MS/MS). The bioconcentration factor (BCF) indicated that the plants affinity to PFOA accumulation was; E. crassipes, > P. sali-cifolium, > C. congestus, > P. x canescens, > P. amphibian, > F. carica, > A. schmidtiana, > X. strumarium,> P. australis, > R. maritime, > S. corymbosus. The concentration of PFOA in the plants and/or reeds was in the range 11.7 to 38 ng/g, with a BCF range of 0.05 to 0.37. The highest BCF was observed in sediment for which its core water had a high salinity, total organic carbon and a pH which was near neutral. As the studied plants had a higher affinity for PFOA, the resultant effect is that riparian plants such as E. crassipes, X. strumarium, and P. salicifolium, typified by a fibrous rooting system, which grow closer to the water edge, exacerbate the accumulation of PFOA in riparian wetlands.

  8. THE SYSTEMIC RISK BUFFER – A CHALLENGING INSTRUMENT FOR ASSESSING

    Directory of Open Access Journals (Sweden)

    BADEA IRINA - RALUCA

    2015-08-01

    Full Text Available The consequences of the global financial crisis have changed the orientation of the regulators from the micro towards the macroeconomic level, which encompasses the financial system as a whole, with its components as individual financial institutions. Needless to say that there is an inherent risk to which every participant to the market is exposed, the systemic risk. Therefore, this paper aims at presenting systemic risk in a clear manner, paying attention to and highlighting several approaches regarding systemic risk in literature and practice. Moreover, the mechanism of systemic risk transmission points out the channels through which systemic risk spreads and affects the real economy. There is also presented a new component of the macroprudential regulation, i.e. the systemic risk buffer (SRB, which is an important instrument to fight against systemic risk along with the other buffers stipulated in the Basel III standards. Hence, the subject dealt in this paper represents a realistic outlook upon the situation of the financial system at the moment, in its struggle to forecast a potential systemic threat and the instruments needed to counteract it in order to diminish its negative effects. In the last part of the paper there is presented evidence from a few countries that started to implement the SRB and G-SII or O-SII buffers or are phased for implementation to the extent of 2019. Tracking the vulnerabilities of the system as a whole, of each of its components and the tranmission channels of systemic risk should be the first step to make before taking any measures against a monetary or financial phenomenon.

  9. Using Computer Simulation Method to Improve Throughput of Production Systems by Buffers and Workers Allocation

    Directory of Open Access Journals (Sweden)

    Kłos Sławomir

    2015-12-01

    Full Text Available This paper proposes the application of computer simulation methods to support decision making regarding intermediate buffer allocations in a series-parallel production line. The simulation model of the production system is based on a real example of a manufacturing company working in the automotive industry. Simulation experiments were conducted for different allocations of buffer capacities and different numbers of employees. The production system consists of three technological operations with intermediate buffers between each operation. The technological operations are carried out using machines and every machine can be operated by one worker. Multi-work in the production system is available (one operator operates several machines. On the basis of the simulation experiments, the relationship between system throughput, buffer allocation and the number of employees is analyzed. Increasing the buffer capacity results in an increase in the average product lifespan. Therefore, in the article a new index is proposed that includes the throughput of the manufacturing system and product life span. Simulation experiments were performed for different configurations of technological operations.

  10. The Riparianness of a Desert Herpetofauna

    Science.gov (United States)

    Charles H. Lowe

    1989-01-01

    Within the Mojave, Sonoran, and Chihuahuan Desert subdivisions of the North American Desert in the U.S., more than half of 143 total amphibian and reptilian species perform as riparian and/or wetland taxa. For the reptiles, but not the amphibians, there is a significant inverse relationship between riparianness (obligate through preferential and facultative to...

  11. PLANT INVASIONS IN RHODE ISLAND RIPARIAN ZONES

    Science.gov (United States)

    The vegetation in riparian zones provides valuable wildlife habitat while enhancing instream habitat and water quality. Forest fragmentation, sunlit edges, and nutrient additions from adjacent development may be sources of stress on riparian zones. Landscape plants may include no...

  12. Internet Teleoperation of a Robot with Streaming Buffer System under Varying Time Delays

    Science.gov (United States)

    Park, Jahng-Hyon; Shin, Wanjae

    It is known that existence of irregular transmission time delay is a major bottleneck for application of advanced robot control schemes to internet telerobotic systems. In the internet teleoperation system, the irregular transmission time delay causes a critical problem, which includes instability and inaccuracy. This paper suggests a practical internet teleoperation system with streaming buffer system, which consists of a buffer, a buffer manager, and a control timer. The proposed system converts the irregular transmission time delay to a constant. So, the system effectively transmits the control input to a remote site to operate a robot stably and accurately. This feature enables short control input intervals. That means the entire system has a large control bandwidth. The validity of the proposed method is demonstrated by experiments of teleoperation from USC (University of Southern California in U. S.A.) to HYU (Hanyang Univ. in Korea) through the Internet. The proposed method is also demonstrated by experiments of teleoperation through the wireless internet.

  13. On buffer overflow duration in a finite-capacity queueing system with multiple vacation policy

    Science.gov (United States)

    Kempa, Wojciech M.

    2017-12-01

    A finite-buffer queueing system with Poisson arrivals and generally distributed processing times, operating under multiple vacation policy, is considered. Each time when the system becomes empty, the service station takes successive independent and identically distributed vacation periods, until, at the completion epoch of one of them, at least one job waiting for service is detected in the buffer. Applying analytical approach based on the idea of embedded Markov chain, integral equations and linear algebra, the compact-form representation for the cumulative distribution function (CDF for short) of the first buffer overflow duration is found. Hence, the formula for the CDF of next such periods is obtained. Moreover, probability distributions of the number of job losses in successive buffer overflow periods are found. The considered queueing system can be efficienly applied in modelling energy saving mechanisms in wireless network communication.

  14. Effects of river restoration on riparian biodiversity in secondary channels of the Pite River, Sweden.

    Science.gov (United States)

    Helfield, James M; Engström, Johanna; Michel, James T; Nilsson, Christer; Jansson, Roland

    2012-01-01

    Between 1850 and 1970, rivers throughout Sweden were channelized to facilitate timber floating. Floatway structures were installed to streamline banks and disconnect flow to secondary channels, resulting in simplified channel morphologies and more homogenous flow regimes. In recent years, local authorities have begun to restore channelized rivers. In this study, we examined the effects of restoration on riparian plant communities at previously disconnected secondary channels of the Pite River. We detected no increase in riparian diversity at restored sites relative to unrestored (i.e., disconnected) sites, but we did observe significant differences in species composition of both vascular plant and bryophyte communities. Disconnected sites featured greater zonation, with mesic-hydric floodplain species represented in plots closest to the stream and mesic-xeric upland species represented in plots farthest from the stream. In contrast, restored sites were most strongly represented by upland species at all distances relative to the stream. These patterns likely result from the increased water levels in reconnected channels where, prior to restoration, upland plants had expanded toward the stream. Nonetheless, the restored fluvial regime has not brought about the development of characteristic flood-adapted plant communities, probably due to the short time interval (ca. 5 years) since restoration. Previous studies have demonstrated relatively quick responses to similar restoration in single-channel tributaries, but secondary channels may respond differently due to the more buffered hydrologic regimes typically seen in anabranching systems. These findings illustrate how restoration outcomes can vary according to hydrologic, climatic and ecological factors, reinforcing the need for site-specific restoration strategies.

  15. [Floristic composition and distribution of the Andean subtropical riparian forests of Lules River, Tucuman, Argentina].

    Science.gov (United States)

    Sirombra, Martín G; Mesa, Leticia M

    2010-03-01

    We studied the floristic composition and distribution of the riparian forest of two hydrographical systems in a subtropical Andean region. Using uni and multivariate techniques, we tested the hypotheses that a differentiable riparian forest exists, composed by native vegetation typical of the Yungas phytogeographical province, and that the distribution of vegetation varied significantly with geomorphologic characteristics. Parallel transects along the water courses were used to collect presence-absence data of vegetation in eleven sites. Detrended Correspondence Analysis defined a group of common riparian species for the studied area (Solanum riparium, Phenax laevigatus, Tipuana tipu, Cestrum parqui, Carica quercifolia, Acacia macracantha, Celtis iguanaea, Juglans australis, Pisoniella arborescens, Baccharis salicifolia, Cinnamomum porphyrium and Eugenia uniflora) and identified two reference sites. The distribution of the riparian vegetation varied significantly with the geomorphic characteristics along the studied sites. Riparian habitats were composed by native and exotic species. A distinct riparian flora, different in structure and function from adjacent terrestrial vegetation, could not be identified. Riparian species were similar to the adjacent terrestrial strata. These species would not be limited by the proximity to the river. Anthropogenic impacts were important factors regulating the introduction and increase of exotic vegetation. The lack of regulation of some activities in the zone could cause serious problems in the integrity of this ecosystem.

  16. Regenerative, Highly-Sensitive, Non-Enzymatic Dopamine Sensor and Impact of Different Buffer Systems in Dopamine Sensing

    Directory of Open Access Journals (Sweden)

    Saumya Joshi

    2018-01-01

    Full Text Available Carbon nanotube field-effect transistors are used extensively in ultra-sensitive biomolecule sensing applications. Along with high sensitivity, the possibility of regeneration is highly desired in bio-sensors. An important constituent of such bio-sensing systems is the buffer used to maintain pH and provide an ionic conducting medium, among its other properties. In this work, we demonstrate highly-sensitive regenerative dopamine sensors and the impact of varying buffer composition and type on the electrolyte gated field effect sensors. The role of the buffer system is an often ignored condition in the electrical characterization of sensors. Non-enzymatic dopamine sensors are fabricated and regenerated in hydrochloric acid (HCl solution. The sensors are finally measured against four different buffer solutions. The impact of the nature and chemical structure of buffer molecules on the dopamine sensors is shown, and the appropriate buffer systems are demonstrated.

  17. Relationships Between Land Use and Stream Nutrient Concentrations in a Highly Urbanized Tropical Region of Brazil: Thresholds and Riparian Zones.

    Science.gov (United States)

    Tromboni, F; Dodds, W K

    2017-07-01

    Nutrient enrichment in streams due to land use is increasing globally, reducing water quality and causing eutrophication of downstream fresh and coastal waters. In temperate developed countries, the intensive use of fertilizers in agriculture is a main driver of increasing nutrient concentrations, but high levels and fast rates of urbanization can be a predominant issue in some areas of the developing world. We investigated land use in the highly urbanized tropical State of Rio de Janeiro, Brazil. We collected total nitrogen, total phosphorus, and inorganic nutrient data from 35 independent watersheds distributed across the State and characterized land use at a riparian and entire watershed scales upstream from each sample station, using ArcGIS. We used regression models to explain land use influences on nutrient concentrations and to assess riparian protection relationships to water quality. We found that urban land use was the primary driver of nutrient concentration increases, independent of the scale of analyses and that urban land use was more concentrated in the riparian buffer of streams than in the entire watersheds. We also found significant thresholds that indicated strong increases in nutrient concentrations with modest increases in urbanization reaching maximum nutrient concentrations between 10 and 46% urban cover. These thresholds influenced calculation of reference nutrient concentrations, and ignoring them led to higher estimates of these concentrations. Lack of sewage treatment in concert with urban development in riparian zones apparently leads to the observation that modest increases in urban land use can cause large increases in nutrient concentrations.

  18. Modeling Phosphorus Capture by Plants Growing in a Multispecies Riparian Buffer

    Directory of Open Access Journals (Sweden)

    J. M. Kelly

    2012-01-01

    Full Text Available The NST 3.0 mechanistic nutrient uptake model was used to explore P uptake to a depth of 120 cm over a 126 d growing season in simulated buffer communities composed of mixtures of cottonwood (Populus deltoids Bartr., switchgrass (Panicum virgatum L., and smooth brome (Bromus inermis Leyss. Model estimates of P uptake from pure stands of smooth brome and cottonwood were 18.9 and 24.5 kg ha−1, respectively. Uptake estimates for mixed stands of trees and grasses were intermediate to pure stands. A single factor sensitivity analysis of parameters used to calculate P uptake for each cover type indicated that Imax, k, ro, and Lo were consistently the most responsive to changes ranging from −50% to +100%. Model exploration of P uptake as a function of soil depth interval indicated that uptake was highest in the 0–30 cm intervals, with values ranging from 85% of total for cottonwood to 56% for switchgrass.

  19. Seasonal estimates of riparian evapotranspiration using remote and in situ measurements

    Science.gov (United States)

    Goodrich, D.C.; Scott, R.; Qi, J.; Goff, B.; Unkrich, C.L.; Moran, M.S.; Williams, D.; Schaeffer, S.; Snyder, K.; MacNish, R.; Maddock, T.; Pool, D.; Chehbouni, A.; Cooper, D.I.; Eichinger, W.E.; Shuttleworth, W.J.; Kerr, Y.; Marsett, R.; Ni, W.

    2000-01-01

    In many semi-arid basins during extended periods when surface snowmelt or storm runoff is absent, groundwater constitutes the primary water source for human habitation, agriculture and riparian ecosystems. Utilizing regional groundwater models in the management of these water resources requires accurate estimates of basin boundary conditions. A critical groundwater boundary condition that is closely coupled to atmospheric processes and is typically known with little certainty is seasonal riparian evapotranspiration ET). This quantity can often be a significant factor in the basin water balance in semi-arid regions yet is very difficult to estimate over a large area. Better understanding and quantification of seasonal, large-area riparian ET is a primary objective of the Semi-Arid Land-Surface-Atmosphere (SALSA) Program. To address this objective, a series of interdisciplinary experimental Campaigns were conducted in 1997 in the San Pedro Basin in southeastern Arizona. The riparian system in this basin is primarily made up of three vegetation communities: mesquite (Prosopis velutina), sacaton grasses (Sporobolus wrightii), and a cottonwood (Populus fremontii)/willow (Salix goodingii) forest gallery. Micrometeorological measurement techniques were used to estimate ET from the mesquite and grasses. These techniques could not be utilized to estimate fluxes from the cottonwood/willow (C/W) forest gallery due to the height (20-30 m) and non-uniform linear nature of the forest gallery. Short-term (2-4 days) sap flux measurements were made to estimate canopy transpiration over several periods of the riparian growing season. Simultaneous remote sensing measurements were used to spatially extrapolate tree and stand measurements. Scaled C/W stand level sap flux estimates were utilized to calibrate a Penman-Monteith model to enable temporal extrapolation between Synoptic measurement periods. With this model and set of measurements, seasonal riparian vegetation water use

  20. Legal Mechanisms for Protecting Riparian Resource Values

    Science.gov (United States)

    Lamb, Berton L.; Lord, Eric

    1992-04-01

    Riparian resources include the borders of rivers, lakes, ponds, and potholes. These border areas are very important for a number of reasons, including stream channel maintenance, flood control, aesthetics, erosion control, fish and wildlife habitat, recreation, and water quality maintenance. These diverse functions are not well protected by law or policy. We reviewed law and policies regarding endangered species habitat designation, land use planning, grazing management, water allocation, takings, and federal permits and licenses, along with the roles of federal, state, and local governments. We discuss the politics of implementing these policies, focusing on the difficulties in changing entrenched water and land use practices. Our review indicates a lack of direct attention to riparian ecosystem issues in almost all environmental and land use programs at every level of government. Protection of riparian resource values requires a means to integrate existing programs to focus on riparian zones.

  1. Tribal experiences and lessons learned in riparian ecosystem restoration

    Science.gov (United States)

    Ronald K. Miller; James E. Enote; Cameron L. Martinez

    1996-01-01

    Riparian ecosystems have been part of the culture of land use of native peoples in the Southwest United States for thousands of years. The experiences of tribal riparian initiatives to incorporate modern elements of environment and development with cultural needs are relatively few. This paper describes tribal case examples and approaches in riparian management which...

  2. Riparian Raptors on USACE Projects: Osprey (Pandion haliaetus)

    National Research Council Canada - National Science Library

    Mitchell, Wilma A; Wolters, M. S

    2000-01-01

    ...) reservoir operations. For management purposes, these raptors are considered riparian generalists because they inhabit riparian zones surrounding streams and lakes on Corps project lands but may seasonally use adjacent...

  3. In Situ Groundwater Denitrification in the Riparian Zone of a Short-Rotation Woody Crop Experimental Watershed

    Science.gov (United States)

    Jeffers, J. B.; Jackson, C. R.; Rau, B.; Pringle, C. M.; Matteson, C.

    2017-12-01

    The southeastern United States has potential to become a major producer of short rotation woody crops (SRWC) for the production of biofuels, but this will require converting to more intensive forest management practices that will increase nitrate (NO3-) loading and alter nitrogen cycling in nearby freshwater ecosystems. Water quality monitoring in an experimental short-rotation woody crop watershed in the Coastal Plain of South Carolina has shown increased concentrations of NO3- in groundwater but no evidence of increased NO3- in riparian groundwater or surface waters. Forested riparian areas established as streamside management zones (SMZ) are known to act as buffers to surface water bodies by mitigating nutrients. The objectives of this study were to quantify denitrification by measuring dinitrogen (N2) and nitrous oxide (N2O) concentrations along groundwater flow paths and analyze relationships between denitrification estimates, nutrients, and water chemistry parameters. A network of piezometers has been established in the Fourmile Experimental Watershed at the Department of Energy - Savannah River Site. Water samples were collected monthly and were analyzed for concentrations of nutrients (temperature, specific conductivity, dissolved oxygen, pH, dissolved organic carbon) and dissolved gases (N2, Ar, N2O). Preliminary data showed greater dissolved N2O concentrations than dissolved N2 concentrations in groundwater. The ratios of N2O to combined end products of denitrification (N2O / N2O+N2) ranged from 0.33 to 0.99. Mean N2O+N2 concentrations were greater in groundwater samples in the SRWC plot and along the SMZ boundary than along the ephemeral stream within the riparian zone. Correlations between water chemistry parameters and N2 concentrations are indicative of known biogeochemical driving factors of denitrification. Continued monthly sampling will be coupled with analysis of nutrient concentrations (NO3-, NH4+, TN) to help determine transport and processing

  4. Ecological assessment of riparian forests in Benin

    NARCIS (Netherlands)

    Natta, A.K.

    2003-01-01

    The present research deals with the flora, phytosociology and ecology of riparian forests. The overall objective of this research is to contribute to a better knowledge of the flora, diversity and ecology of riparian forests in

  5. An Ecohydrological Approach to Riparian Restoration Planning in the American Southwest

    Science.gov (United States)

    Leverich, G. T.; Orr, B.; Diggory, Z.; Dudley, T.; Hatten, J.; Hultine, K. R.; Johnson, M. P.; Orr, D.

    2014-12-01

    Riparian systems across the American southwest region are under threat from a growing and intertwined cast of natural and anthropogenic stressors, including flooding, drought, invasion by non-native plants, wildfire, urban encroachment, and land- and water-use practices. In relatively remote and unregulated systems like the upper Gila River in Arizona, riparian habitat value has persisted reasonably well despite much of it being densely infested with non-native tamarisk (salt cedar). A new concern in the watershed, however, is the eventual arrival of the tamarisk leaf beetle that is expected to soon colonize the tamarisk-infested riparian corridor as the beetle continues to spread across the southwest region. While there are numerous potential benefits to tamarisk suppression (e.g., groundwater conservation, riparian habitat recovery, fire-risk reduction), short-term negative consequences are also possible, such as altered channel hydraulics and canopy defoliation during bird nesting season (e.g., the endangered southwestern willow flycatcher). In preparation for anticipated impacts following beetle colonization, we developed a holistic restoration framework to promote recovery of native riparian habitat and subsequent local increases in avian population. Pivotal to this process was an ecohydrological assessment that identified sustainable restoration sites based on consideration of natural and anthropogenic factors that, together, influence restoration opportunities—flood-scour dynamics, vegetation community structure and resilience, surface- and groundwater availability, soil texture and salinity, wildfire potential, and land-use activities. Data collected included high-resolution remote-sensing products, GIS-based delineation of geomorphic activity, and vegetation field mapping. These data along with other information generated, including pre-biocontrol vegetation monitoring and flycatcher-habitat modeling, were synthesized to produce a comprehensive

  6. Improved Mapping of Riparian Wetlands Using Reach Topography (ECOSERV)

    Science.gov (United States)

    Riparian wetlands provide a suite of ecosystems services including floodwater retention, biogeochemical processing, and habitat provisioning. However in one mid-Atlantic watershed the National Wetlands Inventory was shown to underrepresent these systems by greater than 50%. These...

  7. Release of dissolved phosphorus from riparian wetlands: Evidence for complex interactions among hydroclimate variability, topography and soil properties.

    Science.gov (United States)

    Gu, Sen; Gruau, Gérard; Dupas, Rémi; Rumpel, Cornélia; Crème, Alexandra; Fovet, Ophélie; Gascuel-Odoux, Chantal; Jeanneau, Laurent; Humbert, Guillaume; Petitjean, Patrice

    2017-11-15

    In agricultural landscapes, establishment of vegetated buffer zones in riparian wetlands (RWs) is promoted to decrease phosphorus (P) emissions because RWs can trap particulate P from upslope fields. However, long-term accumulation of P risks the release of dissolved P, since the unstable hydrological conditions in these zones may mobilize accumulated particulate P by transforming it into a mobile dissolved P species. This study evaluates how hydroclimate variability, topography and soil properties interact and influence this mobilization, using a three-year dataset of molybdate-reactive dissolved P (MRDP) and total dissolved P (TDP) concentrations in soil water from two RWs located in an agricultural catchment in western France (Kervidy-Naizin), along with stream P concentrations. Two main drivers of seasonal dissolved P release were identified: i) soil rewetting during water-table rise after dry periods and ii) reductive dissolution of soil Fe (hydr)oxides during prolonged water saturation periods. These mechanisms were shown to vary greatly in space (according to topography) and time (according to intra- and interannual hydroclimate variability). The concentration and speciation of the released dissolved P also varied spatially depending on soil chemistry and local topography. Comparison of sites revealed a similar correlation between soil P speciation (percentage of organic P ranging from 35-70%) and the concentration and speciation of the released P (MRDP from topography and soil chemistry must be considered to decrease the risk of remobilizing legacy soil P when establishing riparian buffer zones in agricultural landscapes. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Small mammals in saltcedar (Tamarix ramosissima) - invaded and native riparian habitats of the western Great Basin

    Science.gov (United States)

    Invasive saltcedar species have replaced native riparian trees on numerous river systems throughout the western US, raising concerns about how this habitat conversion may affect wildlife. For periods ranging from 1-10 years, small mammal populations were monitored at six riparian sites impacted by s...

  9. Melatonin: Buffering the Immune System

    Directory of Open Access Journals (Sweden)

    Juan M. Guerrero

    2013-04-01

    Full Text Available Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed.

  10. Melatonin: Buffering the Immune System

    Science.gov (United States)

    Carrillo-Vico, Antonio; Lardone, Patricia J.; Álvarez-Sánchez, Nuria; Rodríguez-Rodríguez, Ana; Guerrero, Juan M.

    2013-01-01

    Melatonin modulates a wide range of physiological functions with pleiotropic effects on the immune system. Despite the large number of reports implicating melatonin as an immunomodulatory compound, it still remains unclear how melatonin regulates immunity. While some authors argue that melatonin is an immunostimulant, many studies have also described anti-inflammatory properties. The data reviewed in this paper support the idea of melatonin as an immune buffer, acting as a stimulant under basal or immunosuppressive conditions or as an anti-inflammatory compound in the presence of exacerbated immune responses, such as acute inflammation. The clinical relevance of the multiple functions of melatonin under different immune conditions, such as infection, autoimmunity, vaccination and immunosenescence, is also reviewed. PMID:23609496

  11. Characteristics study of bentonite as candidate of buffer materials for radioactive waste disposal system

    International Nuclear Information System (INIS)

    Suryantoro; Arimuladi, S.P.; Sastrowardoyo, P.B.

    1998-01-01

    Literature studies on bentonite characteristic of, as candidate for radioactive waste disposal system, have been conducted. Several information have been obtained from references, which would be contributed on performance assessment of engineered barrier. The functions bentonite includes the buffering of chemical and physical behavior, i.e. swelling property, self sealing, hydraulic conductivities and gas permeability. This paper also presented long-term stability of bentonite in natural condition related to the illitisazation, which could change its buffering capacities. These information, showed that bentonite was satisfied to be used for candidate of buffer materials in radioactive waste disposal system. (author)

  12. Chemical buffering in natural and engineered barrier systems: Thermodynamic constraints and performance assessment consequences

    International Nuclear Information System (INIS)

    Arthur, R.C.; Wei Zhou

    2000-12-01

    Thermodynamic and kinetic constraints on the chemical buffering properties of natural and engineered-barrier systems are derived in this study from theoretical descriptions, incorporated in the reaction-path model, of reversible and irreversible mass transfer in multicomponent, multiphase systems. The buffering properties of such systems are conditional properties because they refer to a specific aqueous species in a system that is open with respect to a specific reactant. The solution to a mathematical statement of this concept requires evaluation of the dependence of the activity of the buffered species on incremental changes in the overall reaction-progress variable. This dependence can be represented by a truncated Taylor's series expansion, where the values of associated derivatives are calculated using finite-difference techniques and mass-balance, charge-balance and mass-action constraints. Kinetic constraints on buffering behavior can also be described if the relation between reactant flux and reaction rate is well defined. This relation is explicit for the important case of advective groundwater flow and water-rock interaction. We apply the theoretical basis of the chemical buffering concept to processes that could affect the performance of a deep geologic repository for nuclear waste. Specifically, we focus on the likelihood that an inverse relation must exist between the buffer intensity and the migration velocity of reaction fronts in systems involving advective or diffusive mass transport. A quantitative understanding of this relation would provide the basis for evaluating the potential role of chemical buffering in achieving the isolation and retardation functions, of the EBS and geosphere in a KBS-3 repository. Our preliminary evaluation of this role considers the effects of chemical buffering on the propagation velocity of a pH front in both the near- and far field. We use a geochemical modeling technique compatible with the reaction-path model to

  13. Spatial and temporal analysis of lake sedimentation under reforestation

    Directory of Open Access Journals (Sweden)

    C.M. Pilgrim

    2015-10-01

    Full Text Available Spatial and temporal land cover changes can reduce or accelerate lake sedimentation. This study was conducted to examine morphometry and bathymetry, and the long-term changes (over 75 years in sedimentation in the Lake Issaqueena reservoir, South Carolina. The watershed and catchment areas were delineated using Light Detection and Ranging (LiDAR based data. Trends in lake surface area and riparian buffer condition (vegetated or unvegetated were determined from historical aerial photography. From 1938 to 2009, the lake experienced a decrease in surface area of approximately 11.33 ha while catchment area increased by 6.99 ha, and lake volume decreased by 320,800.00 m3. Lake surface area decreased in years corresponding to equal coverage or largely unvegetated riparian buffers. Surface area and average annual precipitation were not correlated; therefore other factors such as soil type, riparian buffer condition and changes in land use likely contributed to sedimentation. Shift from agricultural land to forestland in this watershed resulted in a decrease in sedimentation rates by 88.28%. Keywords: Bathymetry, Erosion, Geographic Information Systems (GIS, Land cover, Riparian buffer, Soils

  14. The Influence of Salmon Recolonization on Riparian Communities in the Cedar River, Washington, USA

    Science.gov (United States)

    Moravek, J.; Clipp, H.; Kiffney, P.

    2016-02-01

    Salmon are a valuable resource throughout the Pacific Northwest, but increasing human activity is degrading coastal ecosystems and threatening local salmon populations. Salmon conservation efforts often focus on habitat restoration, including the re-colonization of salmon into historically obstructed areas such as the Cedar River in Washington, USA. However, to assess the long term implications of salmon re-colonization on a landscape scale, it is critical to consider not only the river ecosystem but also the surrounding riparian habitat. Although prior studies suggest that salmon alter riparian food web dynamics, the riparian community on the Cedar River has not yet been characterized. To investigate possible connections between salmon and the riparian habitat after 12 years of re-colonization, we surveyed riparian spider communities along a gradient of salmon inputs (g/m2). In 10-m transects along the banks of the river, we identified spiders and spider webs, collected prey from webs, and characterized nearby aquatic macroinvertebrate communities. We found that the density of aquatic macroinvertebrates, as well as the density of spider prey, both had significant positive relationships with salmon inputs, supporting the hypothesis that salmon provide energy and nutrients for both aquatic and riparian food webs. We also found that spider diversity significantly decreased with salmon inputs, potentially due to confounding factors such as stream gradient or vegetation structure. Although additional information is needed to fully understand this relationship, the significant connection between salmon inputs and spider diversity is compelling motivation for further studies regarding the link between aquatic and riparian systems on the Cedar River. Understanding the connections between salmon and the riparian community is critical to characterizing the long term, landscape-scale implications of sustainable salmon management in the Pacific Northwest.

  15. Chemical buffering in natural and engineered barrier systems: Thermodynamic constraints and performance assessment consequences

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, R.C.; Wei Zhou [Monitor Scientific, LLC, Denver, CO (United States)

    2000-12-01

    Thermodynamic and kinetic constraints on the chemical buffering properties of natural and engineered-barrier systems are derived in this study from theoretical descriptions, incorporated in the reaction-path model, of reversible and irreversible mass transfer in multicomponent, multiphase systems. The buffering properties of such systems are conditional properties because they refer to a specific aqueous species in a system that is open with respect to a specific reactant. The solution to a mathematical statement of this concept requires evaluation of the dependence of the activity of the buffered species on incremental changes in the overall reaction-progress variable. This dependence can be represented by a truncated Taylor's series expansion, where the values of associated derivatives are calculated using finite-difference techniques and mass-balance, charge-balance and mass-action constraints. Kinetic constraints on buffering behavior can also be described if the relation between reactant flux and reaction rate is well defined. This relation is explicit for the important case of advective groundwater flow and water-rock interaction. We apply the theoretical basis of the chemical buffering concept to processes that could affect the performance of a deep geologic repository for nuclear waste. Specifically, we focus on the likelihood that an inverse relation must exist between the buffer intensity and the migration velocity of reaction fronts in systems involving advective or diffusive mass transport. A quantitative understanding of this relation would provide the basis for evaluating the potential role of chemical buffering in achieving the isolation and retardation functions, of the EBS and geosphere in a KBS-3 repository. Our preliminary evaluation of this role considers the effects of chemical buffering on the propagation velocity of a pH front in both the near- and far field. We use a geochemical modeling technique compatible with the reaction-path model

  16. Buffer capacity of biologics--from buffer salts to buffering by antibodies.

    Science.gov (United States)

    Karow, Anne R; Bahrenburg, Sven; Garidel, Patrick

    2013-01-01

    Controlling pH is essential for a variety of biopharmaceutical process steps. The chemical stability of biologics such as monoclonal antibodies is pH-dependent and slightly acidic conditions are favorable for stability in a number of cases. Since control of pH is widely provided by added buffer salts, the current study summarizes the buffer characteristics of acetate, citrate, histidine, succinate, and phosphate buffers. Experimentally derived values largely coincide with values calculated from a model that had been proposed in 1922 by van Slyke. As high concentrated protein formulations become more and more prevalent for biologics, the self-buffering potential of proteins becomes of relevance. The current study provides information on buffer characteristics for pH ranges down to 4.0 and up to 8.0 and shows that a monoclonal antibody at 50 mg/mL exhibits similar buffer capacity as 6 mM citrate or 14 mM histidine (pH 5.0-6.0). Buffer capacity of antibody solutions scales linearly with protein concentration up to more than 200 mg/mL. At a protein concentration of 220 mg/mL, the buffer capacity resembles the buffer capacity of 30 mM citrate or 50 mM histidine (pH 5.0-6.0). The buffer capacity of monoclonal antibodies is practically identical at the process relevant temperatures 5, 25, and 40°C. Changes in ionic strength of ΔI=0.15, in contrast, can alter the buffer capacity up to 35%. In conclusion, due to efficient self-buffering by antibodies in the pH range of favored chemical stability, conventional buffer excipients could be dispensable for pH stabilization of high concentrated protein solutions. Copyright © 2013 American Institute of Chemical Engineers.

  17. Double-layered buffer to enhance the thermal performance in a high-level radioactive waste disposal system

    International Nuclear Information System (INIS)

    Choi, Heui-Joo; Choi, Jongwon

    2008-01-01

    A thermal performance is one of the most important factors in the design of a geological disposal system for high-level radioactive wastes. According to the conceptual design of the Korean Reference disposal System, the maximum temperature of its buffer with a domestic Ca-bentonite is close to the thermal criterion, 100 deg. C. In order to improve the thermal conductivity of its buffer, several kinds of additives are compared. Among the additives, graphite shows the best result in that the thermal conductivity of the bentonite block is more than 2.0 W/m deg. C. We introduced the concept of a double-layered buffer instead of a traditional bentonite block in order to use the applied additive more effectively. The thermal analysis, based upon the three-dimensional finite element method, shows that a double-layered buffer could reduce the maximum temperature on a canister's surface by 7 deg. C under identical conditions when compared with a single-layered buffer. An analytical solution was derived to efficiently analyze the effects of a double-layered buffer. The illustrative cases show that the temperature differences due to a double-layered buffer depend on the thickness of the buffer

  18. Tamarisk coalition - native riparian plant materials program

    Science.gov (United States)

    Stacy Kolegas

    2012-01-01

    The Tamarisk Coalition (TC), a nonprofit organization dedicated to riparian restoration in the western United States, has created a Native Plant Materials Program to address the identified need for native riparian plant species for use in revegetation efforts on the Colorado Plateau. The specific components of the Native Plant Materials Program include: 1) provide seed...

  19. Effect of emergent aquatic insects on bat foraging in a riparian forest.

    Science.gov (United States)

    Fukui, Dai; Murakami, Masashi; Nakano, Shigeru; Aoi, Toshiki

    2006-11-01

    other riparian consumers, resource subsidies from streams can directly enhance the performance or population density of riparian-dependent bats. To conserve and manage bat populations, it is important to protect not only forest ecosystems, but also adjacent aquatic systems such as streams.

  20. Riparian responses to extreme climate and land-use change scenarios.

    Science.gov (United States)

    Fernandes, Maria Rosário; Segurado, Pedro; Jauch, Eduardo; Ferreira, Maria Teresa

    2016-11-01

    Climate change will induce alterations in the hydrological and landscape patterns with effects on riparian ecotones. In this study we assess the combined effect of an extreme climate and land-use change scenario on riparian woody structure and how this will translate into a future risk of riparian functionality loss. The study was conducted in the Tâmega catchment of the Douro basin. Boosted Regression Trees (BRTs) were used to model two riparian landscape indicators related with the degree of connectivity (Mean Width) and complexity (Area Weighted Mean Patch Fractal Dimension). Riparian data were extracted by planimetric analysis of high spatial-resolution Word Imagery Layer (ESRI). Hydrological, climatic and land-use variables were obtained from available datasets and generated with process-based modeling using current climate data (2008-2014), while also considering the high-end RCP8.5 climate-change and "Icarus" socio-economic scenarios for the 2046-2065 time slice. Our results show that hydrological and land-use changes strongly influence future projections of riparian connectivity and complexity, albeit to diverse degrees and with differing effects. A harsh reduction in average flows may impair riparian zones while an increase in extreme rain events may benefit connectivity by promoting hydrologic dynamics with the surrounding floodplains. The expected increase in broad-leaved woodlands and mixed forests may enhance the riparian galleries by reducing the agricultural pressure on the area in the vicinity of the river. According to our results, 63% of river segments in the Tâmega basin exhibited a moderate risk of functionality loss, 16% a high risk, and 21% no risk. Weaknesses and strengths of the method are highlighted and results are discussed based on a resilience perspective with regard to riparian ecosystems. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. A wooded riparian strip set up for nitrogen removal can affect the water flux microbial composition

    Directory of Open Access Journals (Sweden)

    Mizanur Md. Rahman

    2014-02-01

    Full Text Available This research is part of a project aimed at verifying the potential of a specifically assessed wooded riparian zone in removing excess of combined nitrogen from the Zero river flow for the reduction of nutrient input into Venice Lagoon. Specific objectives were pursued to determine seasonal fluctuations of the microbial populations from the input water to a drainage ditch, conveying back the flux into the river after passing through the soil of the wooded riparian strip. The bacterial communities were determined by combined approaches involving cultivation, microscopic methods and DNA based techniques to determine both culturable and total microbial community in water. The results indicate that the size of the bacterial population, including the culturable fraction, increases from the river to the drainage ditch especially on the warm season. The multiple approach here adopted enabled also to demonstrate that the special condition created in the buffer strip supports the development and the metabolism of the microbial community. The nature of the bacterial population, in terms of phylotypes distribution, was investigated by 16S rDNA analysis indicating that the most represented genera belong to Gamma-proteobacteria, which is known to include an exceeding number of important pathogens. In spring, the effect of the buffer strip seems to significantly reduce such a sub-population. The changes observed for the total bacterial community composition become much evident in summer, as revealed by both denaturing gradient gel electrophoresis cluster analysis and by the diversity index calculation. The hydraulic management coupled to the suspension of farming practices and the development of the woody and herbaceous vegetation resulted in a condition suitable for the containment of undesired microbiota (mainly during the spring season while continuing to support denitrification activity (especially throughout the summer as verified by the total nitrogen

  2. Riparian Raptors on USACE Projects: Bald Eagle (Haliaeetus leucocephalus)

    National Research Council Canada - National Science Library

    Mitchell, Wilma

    2000-01-01

    ...) reservoir operations. For management purposes, these raptors are considered riparian generalists because they inhabit the riparian zones surrounding streams and lakes of Corps projects but may seasonally use adjacent...

  3. In vivo predictive dissolution: transport analysis of the CO2 , bicarbonate in vivo buffer system.

    Science.gov (United States)

    Krieg, Brian J; Taghavi, Seyed Mohammad; Amidon, Gordon L; Amidon, Gregory E

    2014-11-01

    Development of an oral in vivo predictive dissolution medium for acid drugs with a pKa in the physiological range (e.g., Biopharmaceutics Classification System Class IIa) requires transport analysis of the complex in vivo CO2 /bicarbonate buffering system. In this report, we analyze this buffer system using hydrodynamically defined rotating disk dissolution. Transport analysis of drug flux was predicted using the film model approach of Mooney et al based on equilibrium assumptions as well as accounting for the slow hydration reaction, CO2 + H2 O → H2 CO3 . The accuracy of the models was compared with experimentally determined results using the rotating disk dissolution of ibuprofen, indomethacin, and ketoprofen. The equilibrium and slow hydration reaction rate models predict significantly different dissolution rates. The experimental results are more accurately predicted by accounting for the slow hydration reaction under a variety of pH and hydrodynamic conditions. Although the complex bicarbonate buffering system requires further consideration given its dynamic nature in vivo, a simplifying irreversible reaction (IRR) transport analysis accurately predicts in vitro rotating disk dissolution rates of several carboxylic acid drugs. This IRR transport model provides further insight into bicarbonate buffer and can be useful in developing more physiologically relevant buffer systems for dissolution testing. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Riparian Cottonwood Ecosystems and Regulated Flows in Kootenai and Yakima Sub-Basins : Volume III (Overview and Tools).

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, Bob; Braatne, Jeffrey H.

    2001-10-01

    Riparian vegetation and especially cottonwood and willow plant communities are dependent on normative flows and especially, spring freshette, to provide conditions for recruitment. These plant communities therefore share much in common with a range of fish species that require natural flow conditions to stimulate reproduction. We applied tools and techniques developed in other areas to assess riparian vegetation in two very different sub-basins within the Columbia Basin. Our objectives were to: Document the historic impact of human activity on alluvial floodplain areas in both sub-basins; Provide an analysis of the impacts of flow regulation on riparian vegetation in two systems with very different flow regulation systems; Demonstrate that altered spring flows will, in fact, result in recruitment to cottonwood stands, given other land uses impacts on each river and the limitations imposed by other flow requirements; and Assess the applicability of remote sensing tools for documenting the distribution and health of cottonwood stands and riparian vegetation that can be used in other sub-basins.

  5. Evaluation of the riparian forest state program in Pitangueiras county, Parana

    OpenAIRE

    Peres, Marli Candalaft Alcantara Parra; Universidade Estadual de Londrina/UEL; Ralisch, Ricardo; Universidade Estadual de Londrina/UEL; Ripol, Cristovon Videira; Instituto Paranaense de Assistência Técnica e Extensão Rural do Paraná/EMATER

    2009-01-01

    Riparian forest restoration is fundamental for maintenance of vegetable, animal and human life. The objective of this study was to evaluate the efficiency of a Riparian Forest state program in the enlargement of the riparian forests in Pitangueiras county, state of Paraná, in the period of 2004 to 2006. Concerning the riparian reforestation, it was ansewered the reasons that convinced the farmers to join the program, the main difficulties found in its execution, and their views on environment...

  6. SODR Memory Control Buffer Control ASIC

    Science.gov (United States)

    Hodson, Robert F.

    1994-01-01

    The Spacecraft Optical Disk Recorder (SODR) is a state of the art mass storage system for future NASA missions requiring high transmission rates and a large capacity storage system. This report covers the design and development of an SODR memory buffer control applications specific integrated circuit (ASIC). The memory buffer control ASIC has two primary functions: (1) buffering data to prevent loss of data during disk access times, (2) converting data formats from a high performance parallel interface format to a small computer systems interface format. Ten 144 p in, 50 MHz CMOS ASIC's were designed, fabricated and tested to implement the memory buffer control function.

  7. Chemical and microbiological properties of an eutrophic Oxisol under riparian forest buffer reforestation and pasture. Propriedades químicas e microbiológicas de um Latossolo Vermelho eutrófico sob reflorestamento de mata ciliar e pastagem.

    Directory of Open Access Journals (Sweden)

    Fabiana Marise PULITANO

    2013-06-01

    Full Text Available Regardless of their ecological importance, riparian forest strips are frequently suppressed to allow greater expansion of arable and urban areas. Agroforestry might be an effective alternative to recompose riparian forests. Soil chemical and microbial properties are important environmental indicators to evaluate the reclamation process. This study tested the hypothesis that, in the course of time, reforestation by means of agroforestry improved soil microbial and chemical properties in a riparian forest buffer. Soil samples were collected from three layers (0.0-2.5; 2.5-7.5; 7.5-20 cm in two sectors of a reforested riparian buffer strip in Cananéia Farm, São Paulo state, Brazil, one 18 years old and other 28 years old, and in an adjacent pasture area. The samples were assessed for pHH2O, available P and K, exchangeable, Ca, Mg and Al, H+Al, sum of bases (SB, pH 7.0 CEC, percent base saturation (V, soil organic matter (SOM and light organic matter (LOM. Microbial biomass carbon (MBC and nitrogen (MBN were analyzed only in the first layer. The pattern for Ca, Mg, SB and V (all layers was 28-year-old sector = 18-year-old-sector > pasture. The SOM at 0.0-2.5 cm was higher in the 28-year-old sector. The LOM pattern was 28-year-old sector > 18-year-old sector > pasture. MBC did not differ among areas. MBN was significantly higher comparing the 28-year-old sector and the pasture area. The results probably reflected the higher litterfall and the N-richer organic matter in the reforested sectors. Reforestation by means of agroforestry improved soil quality, contributing to the ecosystem sustainability. Independentemente de sua importância ecológica, matas ciliares são frequentemente suprimidas e ocupadas por lavouras e cidades. Agroflorestas podem ser eficazes para a recomposição dessas áreas. Propriedades químicas e microbiológicas do solo são importantes indicadores ambientais para avaliar o processo de recomposição. Este estudo testou a

  8. Buffer-regulated biocorrosion of pure magnesium.

    Science.gov (United States)

    Kirkland, Nicholas T; Waterman, Jay; Birbilis, Nick; Dias, George; Woodfield, Tim B F; Hartshorn, Richard M; Staiger, Mark P

    2012-02-01

    Magnesium (Mg) alloys are being actively investigated as potential load-bearing orthopaedic implant materials due to their biodegradability in vivo. With Mg biomaterials at an early stage in their development, the screening of alloy compositions for their biodegradation rate, and hence biocompatibility, is reliant on cost-effective in vitro methods. The use of a buffer to control pH during in vitro biodegradation is recognised as critically important as this seeks to mimic pH control as it occurs naturally in vivo. The two different types of in vitro buffer system available are based on either (i) zwitterionic organic compounds or (ii) carbonate buffers within a partial-CO(2) atmosphere. This study investigated the influence of the buffering system itself on the in vitro corrosion of Mg. It was found that the less realistic zwitterion-based buffer did not form the same corrosion layers as the carbonate buffer, and was potentially affecting the behaviour of the hydrated oxide layer that forms on Mg in all aqueous environments. Consequently it was recommended that Mg in vitro experiments use the more biorealistic carbonate buffering system when possible.

  9. Riparian swallows as integrators of landscape change in a multiuse river system: implications for aquatic-to-terrestrial transfers of contaminants.

    Science.gov (United States)

    Alberts, Jeremy M; Sullivan, S Mažeika P; Kautza, A

    2013-10-01

    Recent research has highlighted the transfer of contaminants from aquatic to terrestrial ecosystems via predation of aquatic emergent insects by riparian consumers. The influence of adjacent land use and land cover (LULC) on aquatic-to-terrestrial contaminant transfer, however, has received limited attention. From 2010 to 2012, at 11 river reaches in the Scioto River basin (OH, USA), we investigated the relationships between LULC and selenium (Se) and mercury (Hg) concentrations in four species of riparian swallows. Hg concentrations in swallows were significantly higher at rural reaches than at urban reaches (t=-3.58, Pemergent insects. For example, tree swallows (Tachycineta bicolor) at urban reaches exhibited a higher proportion of aquatic prey in their diet, fed at a higher trophic level, and exhibited elevated Se levels. We also found that both Se and Hg concentrations in adult swallows were significantly higher than those observed in nestlings at both urban and rural reaches (Se: t=-2.83, P=0.033, df=3; Hg: t=-3.22, P=0.024, df=3). Collectively, our results indicate that riparian swallows integrate contaminant exposure in linked aquatic-terrestrial systems and that LULC may strongly regulate aquatic contaminant flux to terrestrial consumers. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Buffer mass test - data aquisition and data processing systems

    International Nuclear Information System (INIS)

    Hagvall, B.

    1982-08-01

    This report describes data aquisition and data processing systems used for the Buffer Mass Test at Stripa. A data aquisition system, designed mainly to provide high reliability, in Stripa produces raw-data log tapes. Copies of these tapes are mailed to the computer center at the University of Luleaa for processing of raw-data. The computer systems in Luleaa offer a wide range of processing facilities: large mass storage units, several plotting facilities, programs for processing and monitoring of vast amounts of data, etc.. (Author)

  11. Spatial-structural analysis of leafless woody riparian vegetation for hydraulic considerations

    Science.gov (United States)

    Weissteiner, Clemens; Jalonen, Johanna; Järvelä, Juha; Rauch, Hans Peter

    2013-04-01

    Woody riparian vegetation is a vital element of riverine environments. On one hand woody riparian vegetation has to be taken into account from a civil engineering point of view due to boundary shear stress and vegetation drag. On the other hand it has to be considered from a river ecological point of view due to shadowing effects and as a source of organic material for aquatic habitats. In hydrodynamic and hydro-ecological studies the effects of woody riparian vegetation on flow patterns are usually investigated on a very detailed level. On the contrary vegetation elements and their spatial patterns are generally analysed and discussed on the basis of an integral approach measuring for example basal diameters, heights and projected plant areas. For a better understanding of the influence of woody riparian vegetation on turbulent flow and on river ecology, it is essential to record and analyse plant data sets on the same level of quality as for hydrodynamic or hydro-ecologic purposes. As a result of the same scale of the analysis it is possible to incorporate riparian vegetation as a sub-model in the hydraulic analysis. For plant structural components, such as branches on different topological levels it is crucial to record plant geometrical parameters describing the habitus of the plant on branch level. An exact 3D geometrical model of real plants allows for an extraction of various spatial-structural plant parameters. In addition, allometric relationships help to summarize and describe plant traits of riparian vegetation. This paper focuses on the spatial-structural composition of leafless riparia woddy vegetation. Structural and spatial analyses determine detailed geometric properties of the structural components of the plants. Geometrical and topological parameters were recorded with an electro-magnetic scanning device. In total, 23 plants (willows, alders and birches) were analysed in the study. Data were recorded on branch level, which allowed for the

  12. The influence of riparian-hyporheic zone on the hydrological responses in an intermittent stream

    Directory of Open Access Journals (Sweden)

    A. Butturini

    2002-01-01

    Full Text Available Stream and riparian groundwater hydrology has been studied in a small intermittent stream draining a forested catchment for a system representative of a Mediterranean climate. The relationship between precipitation and stream runoff and the interactions between stream water and the surrounding riparian groundwater have been analysed under a wide spectrum of meteorological conditions. The hypothesis that the hydrological condition of the near-stream groundwater compartment can regulate the runoff generation during precipitation events was tested. Stream runoff is characterised by a summer dry period, and precipitation input explained only 25% of runoff variability over the study period (r2 =0.25, d.f.=51, p2=0.80, d.f.=34, p Keywords: riparian zone, groundwater hydrology, runoff, intermittent stream, Mediterranean climate

  13. Riparian Vegetation Mapping Along the Hanford Reach

    International Nuclear Information System (INIS)

    FOGWELL, T.W.

    2003-01-01

    During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY2002

  14. Riparian Vegetation Mapping Along the Hanford Reach

    Energy Technology Data Exchange (ETDEWEB)

    FOGWELL, T.W.

    2003-07-11

    During the biological survey and inventory of the Hanford Site conducted in the mid-1990s (1995 and 1996), preliminary surveys of the riparian vegetation were conducted along the Hanford Reach. These preliminary data were reported to The Nature Conservancy (TNC), but were not included in any TNC reports to DOE or stakeholders. During the latter part of FY2001, PNNL contracted with SEE Botanical, the parties that performed the original surveys in the mid 1990s, to complete the data summaries and mapping associated with the earlier survey data. Those data sets were delivered to PNNL and the riparian mapping by vegetation type for the Hanford Reach is being digitized during the first quarter of FY2002. These mapping efforts provide the information necessary to create subsequent spatial data layers to describe the riparian zone according to plant functional types (trees, shrubs, grasses, sedges, forbs). Quantification of the riparian zone by vegetation types is important to a number of DOE'S priority issues including modeling contaminant transport and uptake in the near-riverine environment and the determination of ecological risk. This work included the identification of vegetative zones along the Reach by changes in dominant plant species covering the shoreline from just to the north of the 300 Area to China Bar near Vernita. Dominant and indicator species included Agropyron dasytachyudA. smithii, Apocynum cannabinum, Aristida longiseta, Artemisia campestris ssp. borealis var scouleriana, Artemisa dracunculus, Artemisia lindleyana, Artemisia tridentata, Bromus tectorum, Chrysothamnus nauseosus, Coreopsis atkinsoniana. Eleocharis palustris, Elymus cinereus, Equisetum hyemale, Eriogonum compositum, Juniperus trichocarpa, Phalaris arundinacea, Poa compressa. Salk exigua, Scirpus acutus, Solidago occidentalis, Sporobolus asper,and Sporobolus cryptandrus. This letter report documents the data received, the processing by PNNL staff, and additional data gathered in FY

  15. Influences of watershed geomorphology on extent and composition of riparian vegetation

    Science.gov (United States)

    Blake M. Engelhardt; Peter J. Weisberg; Jeanne C. Chambers

    2011-01-01

    Watershed (drainage basin) morphometry and geology were derived from digital data sets (DEMs and geologic maps). Riparian corridors were classified into five vegetation types (riparian forest, riparian shrub, wet/mesic meadow, dry meadow and shrub dry meadow) using high-resolution aerial photography. Regression and multivariate analyses were used to relate geomorphic...

  16. Riparian Cottonwood Ecosystems and Regulated Flows in Kootenai and Yakima Sub-Basins : Volume II Yakima (Overview, Report, Appendices).

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, Bob; Braatne, Jeffrey H.

    2001-10-01

    Riparian vegetation and especially cottonwood and willow plant communities are dependent on normative flows and especially, spring freshette, to provide conditions for recruitment. These plant communities therefore share much in common with a range of fish species that require natural flow conditions to stimulate reproduction. We applied tools and techniques developed in other areas to assess riparian vegetation in two very different sub-basins within the Columbia Basin. Our objectives were to: Document the historic impact of human activity on alluvial floodplain areas in both sub-basins; Provide an analysis of the impacts of flow regulation on riparian vegetation in two systems with very different flow regulation systems; Demonstrate that altered spring flows will, in fact, result in recruitment to cottonwood stands, given other land uses impacts on each river and the limitations imposed by other flow requirements; and Assess the applicability of remote sensing tools for documenting the distribution and health of cottonwood stands and riparian vegetation that can be used in other sub-basins.

  17. Methane emissions in Danish riparian wetlands

    DEFF Research Database (Denmark)

    Audet, Joachim; Johansen, Jan Ravn; Andersen, Peter Mejlhede

    2013-01-01

    The present study was conducted to (i) investigate parameters influencing the fluxes of the greenhouse gas methane (CH4) in Danish riparian wetlands with contrasting vegetation characteristics and (ii) develop models relating CH4 emissions to soil and/or vegetation parameters integrating the spat......The present study was conducted to (i) investigate parameters influencing the fluxes of the greenhouse gas methane (CH4) in Danish riparian wetlands with contrasting vegetation characteristics and (ii) develop models relating CH4 emissions to soil and/or vegetation parameters integrating...

  18. Riparian plant community responses to increased flooding: a meta-analysis.

    Science.gov (United States)

    Garssen, Annemarie G; Baattrup-Pedersen, Annette; Voesenek, Laurentius A C J; Verhoeven, Jos T A; Soons, Merel B

    2015-08-01

    A future higher risk of severe flooding of streams and rivers has been projected to change riparian plant community composition and species richness, but the extent and direction of the expected change remain uncertain. We conducted a meta-analysis to synthesize globally available experimental evidence and assess the effects of increased flooding on (1) riparian adult plant and seedling survival, (2) riparian plant biomass and (3) riparian plant species composition and richness. We evaluated which plant traits are of key importance for the response of riparian plant species to flooding. We identified and analysed 53 papers from ISI Web of Knowledge which presented quantitative experimental results on flooding treatments and corresponding control situations. Our meta-analysis demonstrated how longer duration of flooding, greater depth of flooding and, particularly, their combination reduce seedling survival of most riparian species. Plant height above water level, ability to elongate shoots and plasticity in root porosity were decisive for adult plant survival and growth during longer periods of flooding. Both 'quiescence' and 'escape' proved to be successful strategies promoting riparian plant survival, which was reflected in the wide variation in survival (full range between 0 and 100%) under fully submerged conditions, while plants that protrude above the water level (>20 cm) almost all survive. Our survey confirmed that the projected increase in the duration and depth of flooding periods is sufficient to result in species shifts. These shifts may lead to increased or decreased riparian species richness depending on the nutrient, climatic and hydrological status of the catchment. Species richness was generally reduced at flooded sites in nutrient-rich catchments and sites that previously experienced relatively stable hydrographs (e.g. rain-fed lowland streams). Species richness usually increased at sites in desert and semi-arid climate regions (e.g. intermittent

  19. Riparian zone controls on base cation concentrations in boreal streams

    Science.gov (United States)

    Ledesma, J. L. J.; Grabs, T.; Futter, M. N.; Bishop, K. H.; Laudon, H.; Köhler, S. J.

    2013-01-01

    Forest riparian zones are a major in control of surface water quality. Base cation (BC) concentrations, fluxes, and cycling in the riparian zone merit attention because of increasing concern of negative consequences for re-acidification of surface waters from future climate and forest harvesting scenarios. We present a two-year study of BC and silica (Si) flow-weighted concentrations from 13 riparian zones and 14 streams in a boreal catchment in northern Sweden. The Riparian Flow-Concentration Integration Model (RIM) was used to estimate riparian zone flow-weighted concentrations and tested to predict the stream flow-weighted concentrations. Spatial variation in BC and Si concentrations as well as in flow-weighted concentrations was related to differences in Quaternary deposits, with the largest contribution from lower lying silty sediments and the lowest contribution from wetland areas higher up in the catchment. Temporal stability in the concentrations of most elements, a remarkably stable Mg / Ca ratio in the soil water and a homogeneous mineralogy suggest that the stable patterns found in the riparian zones are a result of distinct mineralogical upslope groundwater signals integrating the chemical signals of biological and chemical weathering. Stream water Mg / Ca ratio indicates that the signal is subsequently maintained in the streams. RIM gave good predictions of Ca, Mg, and Na flow-weighted concentrations in headwater streams. The difficulty in modelling K and Si suggests a stronger biogeochemical influence on these elements. The observed chemical dilution effect with flow in the streams was related to variation in groundwater levels and element concentration profiles in the riparian zones. This study provides a first step toward specific investigations of the vulnerability of riparian zones to changes induced by forest management or climate change, with focus on BC or other compounds.

  20. Riparian Habitat Management for Mammals on Corps of Engineers Projects

    National Research Council Canada - National Science Library

    Martin, Chester

    2002-01-01

    .... This note provides an overview of the importance of riparian ecosystems to mammals, discusses regional variation in mammal communities characteristic of riparian zones, identifies potential impacts...

  1. Water use sources of desert riparian Populus euphratica forests.

    Science.gov (United States)

    Si, Jianhua; Feng, Qi; Cao, Shengkui; Yu, Tengfei; Zhao, Chunyan

    2014-09-01

    Desert riparian forests are the main body of natural oases in the lower reaches of inland rivers; its growth and distribution are closely related to water use sources. However, how does the desert riparian forest obtains a stable water source and which water sources it uses to effectively avoid or overcome water stress to survive? This paper describes an analysis of the water sources, using the stable oxygen isotope technique and the linear mixed model of the isotopic values and of desert riparian Populus euphratica forests growing at sites with different groundwater depths and conditions. The results showed that the main water source of Populus euphratica changes from water in a single soil layer or groundwater to deep subsoil water and groundwater as the depth of groundwater increases. This appears to be an adaptive selection to arid and water-deficient conditions and is a primary reason for the long-term survival of P. euphratica in the desert riparian forest of an extremely arid region. Water contributions from the various soil layers and from groundwater differed and the desert riparian P. euphratica forests in different habitats had dissimilar water use strategies.

  2. Adaptation of the QBR index for use in riparian forests of central Ohio

    Science.gov (United States)

    Stephanie R. Colwell; David M. Hix

    2008-01-01

    Although high quality riparian forests are an endangered ecosystem type throughout the world, there has been no ecological index to measure the habitat quality of riparian forests in Ohio. The QBR (qualitat del bosc de ribera, or riparian forest quality) index was developed to assess the quality of habitat in Mediterranean forested riparian areas, and we have modified...

  3. SNAG AND LARGE WOODY DEBRIS DYNAMICS IN RIPARIAN FORESTS

    Science.gov (United States)

    Important components of riparian forests are snags and streamside large woody debris (LWD) because they are functional in maintaining water quality and providing habitat for numerous plants and animals. To effectively manage riparian forests, it is important to understand the dy...

  4. Signature-based store checking buffer

    Science.gov (United States)

    Sridharan, Vilas; Gurumurthi, Sudhanva

    2015-06-02

    A system and method for optimizing redundant output verification, are provided. A hardware-based store fingerprint buffer receives multiple instances of output from multiple instances of computation. The store fingerprint buffer generates a signature from the content included in the multiple instances of output. When a barrier is reached, the store fingerprint buffer uses the signature to verify the content is error-free.

  5. A hierarchical updating method for finite element model of airbag buffer system under landing impact

    Directory of Open Access Journals (Sweden)

    He Huan

    2015-12-01

    Full Text Available In this paper, we propose an impact finite element (FE model for an airbag landing buffer system. First, an impact FE model has been formulated for a typical airbag landing buffer system. We use the independence of the structure FE model from the full impact FE model to develop a hierarchical updating scheme for the recovery module FE model and the airbag system FE model. Second, we define impact responses at key points to compare the computational and experimental results to resolve the inconsistency between the experimental data sampling frequency and experimental triggering. To determine the typical characteristics of the impact dynamics response of the airbag landing buffer system, we present the impact response confidence factors (IRCFs to evaluate how consistent the computational and experiment results are. An error function is defined between the experimental and computational results at key points of the impact response (KPIR to serve as a modified objective function. A radial basis function (RBF is introduced to construct updating variables for a surrogate model for updating the objective function, thereby converting the FE model updating problem to a soluble optimization problem. Finally, the developed method has been validated using an experimental and computational study on the impact dynamics of a classic airbag landing buffer system.

  6. Estimation of Separation Buffers for Wind-Prediction Error in an Airborne Separation Assistance System

    Science.gov (United States)

    Consiglio, Maria C.; Hoadley, Sherwood T.; Allen, B. Danette

    2009-01-01

    Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.

  7. Effects of riparian vegetation development in a restored lowland stream

    NARCIS (Netherlands)

    Vargas-Luna, A.; Crosato, A.; Hoitink, A.J.F.; Groot, J.; Uijttewaal, W.S.J.

    2016-01-01

    This paper presents the morphodynamic effects of riparian vegetation growth in a lowland restored stream. Hydrological series, high-resolution bathymetric data and aerial photographs are combined in the study. The vegetation root system was found to assert a strong control on soil stabilization,

  8. Riparian erosion vulnerability model based on environmental features.

    Science.gov (United States)

    Botero-Acosta, Alejandra; Chu, Maria L; Guzman, Jorge A; Starks, Patrick J; Moriasi, Daniel N

    2017-12-01

    Riparian erosion is one of the major causes of sediment and contaminant load to streams, degradation of riparian wildlife habitats, and land loss hazards. Land and soil management practices are implemented as conservation and restoration measures to mitigate the environmental problems brought about by riparian erosion. This, however, requires the identification of vulnerable areas to soil erosion. Because of the complex interactions between the different mechanisms that govern soil erosion and the inherent uncertainties involved in quantifying these processes, assessing erosion vulnerability at the watershed scale is challenging. The main objective of this study was to develop a methodology to identify areas along the riparian zone that are susceptible to erosion. The methodology was developed by integrating the physically-based watershed model MIKE-SHE, to simulate water movement, and a habitat suitability model, MaxEnt, to quantify the probability of presences of elevation changes (i.e., erosion) across the watershed. The presences of elevation changes were estimated based on two LiDAR-based elevation datasets taken in 2009 and 2012. The changes in elevation were grouped into four categories: low (0.5 - 0.7 m), medium (0.7 - 1.0 m), high (1.0 - 1.7 m) and very high (1.7 - 5.9 m), considering each category as a studied "species". The categories' locations were then used as "species location" map in MaxEnt. The environmental features used as constraints to the presence of erosion were land cover, soil, stream power index, overland flow, lateral inflow, and discharge. The modeling framework was evaluated in the Fort Cobb Reservoir Experimental watershed in southcentral Oklahoma. Results showed that the most vulnerable areas for erosion were located at the upper riparian zones of the Cobb and Lake sub-watersheds. The main waterways of these sub-watersheds were also found to be prone to streambank erosion. Approximatively 80% of the riparian zone (streambank

  9. Riparian Raptors on USACE Projects: Red-Shouldered Hawk (Buteo lineatus)

    National Research Council Canada - National Science Library

    Mitchell, Wilma

    2000-01-01

    ...) reservoir operations. For management purposes, these raptors are considered riparian generalists because they inhabit the riparian zones surrounding streams and lakes on Corps project lands but may seasonally use adjacent...

  10. HYDROGEOMORPHIC SETTING, CHARACTERISTICS, AND RESPONSE TO STREAM INCISION OF MONTANA RIPARIAN MEADOWS IN THE CENTRAL GREAT BASIN--IMPLICATIONS FOR RESTORATION

    Science.gov (United States)

    Riparian wet meadow complexes in the mountains of the central Great Basin are scarce, ecologically important systems that are threatened by stream incision. An interdisciplinary group has investigated 1) the origin, characteristics, and controls on the evolution of these riparian...

  11. The StreamCat Dataset: Accumulated Attributes for NHDPlusV2 (Version 2.1) Catchments Riparian Buffer for the Conterminous United States: Facility Registry Services (FRS) : Toxic Release Inventory (TRI) , National Pollutant Discharge Elimination System (NPDES) , and Superfund Sites

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset represents the estimated density of georeferenced sites within individual, local NHDPlusV2 catchments and upstream, contributing watersheds riparian...

  12. Assessing the extent and diversity of riparian ecosystems in Sonora, Mexico

    Science.gov (United States)

    Scott, M.L.; Nagler, P.L.; Glenn, E.P.; Valdes-Casillas, C.; Erker, J.A.; Reynolds, E.W.; Shafroth, P.B.; Gomez-Limon, E.; Jones, C.L.

    2009-01-01

    Conservation of forested riparian ecosystems is of international concern. Relatively little is known of the structure, composition, diversity, and extent of riparian ecosystems in Mexico. We used high- and low-resolution satellite imagery from 2000 to 2006, and ground-based sampling in 2006, to assess the spatial pattern, extent, and woody plant composition of riparian forests across a range of spatial scales for the state of Sonora, Mexico. For all 3rd and higher order streams, river bottomlands with riparian forests occupied a total area of 2,301 km2. Where forested bottomlands remained, on average, 34% of the area had been converted to agriculture while 39% remained forested. We estimated that the total area of riparian forest along the principal streams was 897 km2. Including fencerow trees, the total forested riparian area was 944 km2, or 0.5% of the total land area of Sonora. Ground-based sampling of woody riparian vegetation consisted of 92, 50 m radius circular plots. About 79 woody plant species were noted. The most important tree species, based on cover and frequency, were willow species Salix spp. (primarily S. goodingii and S. bonplandiana), mesquite species Prosopis spp. (primarily P. velutina), and Fremont cottonwood Populus fremontii. Woody riparian taxa at the reach scale showed a trend of increasing diversity from north to south within Sonora. Species richness was greatest in the willow-bald cypress Taxodium distichum var. mexicanum-Mexican cottonwood P. mexicana subsp. dimorphia ecosystem. The non-native tamarisk Tamarix spp. was rare, occurring at just three study reaches. Relatively natural stream flow patterns and fluvial disturbance regimes likely limit its establishment and spread. ?? 2008 Springer Science + Business Media BV.

  13. Insects of the riparian

    Science.gov (United States)

    Terrence J. Rogers

    1996-01-01

    This paper describes life histories, defoliation problems and other activities of insects associated with forest tree species growing along high elevation streams and river banks. In addition, examples of insects and diseases associated with lower elevation riparian areas are given.

  14. Riparian Habitat Management for Reptiles and Amphibians on Corps of Engineers Projects

    National Research Council Canada - National Science Library

    Dickerson, Dena

    2001-01-01

    ... important taxonomic groups such as reptiles and amphibians. This note provides an overview of the importance of riparian habitat at Corps projects for reptiles and amphibians, identifies riparian zone functions and habitat characteristics, provides examples of representative taxa and regional comparisons, and describes impacts of riparian habitat modification.

  15. Riparian forests, a unique but endangered ecosystem in Benin

    NARCIS (Netherlands)

    Natta, A.K.; Sinsin, B.; Maesen, van der L.J.G.

    2002-01-01

    Riparian forests are often small in area, but are of extreme ecological and economic value for local people. The interest of riparian forests lies in their resources: basically fertile and moist soils, water, wood and non-timber forest products that are utilised by neighbouring populations to

  16. Reconstructing Historical Riparian Conditions of Two River Basins in Eastern Oregon, USA

    Science.gov (United States)

    McAllister, Lynne S.

    2008-09-01

    As land use continues to alter riparian areas, historical information is increasingly needed to help establish reference conditions for monitoring and assessment. I developed and applied a procedure in the John Day and Deschutes river basins of eastern Oregon for synthesizing historical documentary records available across broad spatial areas to reconstruct 19th-century riparian conditions. The study area was stratified by ecoregion and stream physical characteristics to partition regional variability. Three primary data sources—General Land Office survey notes, historical photographs, and written accounts—provided descriptive records, which were grouped by topic to develop common riparian attributes. The number of records for each attribute was tallied by stratum to compare and contrast riparian structure and composition across strata and ecoregions. Detailed descriptions of historical riparian conditions using the original documentary records further illustrated the unique riparian conditions in each stratum. Similarities and differences in historical riparian structure and composition at the stratum and ecoregion levels were evident based on the distributional pattern and numbers of records of attributes across strata. A high number of repeated observations within and among primary data sources helped to corroborate descriptive data. Although these reference data cannot provide the detail needed for rigorous quantitative assessments, they do describe a range of conditions approaching a minimally disturbed condition and provide an important perspective for conducting riparian assessments in highly disturbed regions where least-disturbed reference sites are often poor examples of a desired condition.

  17. Aquatic subsidies transport anthropogenic nitrogen to riparian spiders

    Energy Technology Data Exchange (ETDEWEB)

    Akamatsu, Fumikazu, E-mail: f-akamt55@pwri.go.jp [Department of Environmental Sciences, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan); Toda, Hideshige [Department of Environmental Sciences, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan)

    2011-05-15

    Stable nitrogen isotopic composition ({delta}{sup 15}N) of aquatic biota increases with anthropogenic N inputs such as sewage and livestock waste downstream. Increase in {delta}{sup 15}N of riparian spiders downstream may reflect the anthropogenic pollution exposure through predation on aquatic insects. A two-source mixing model based on stable carbon isotopic composition showed the greatest dependence on aquatic insects (84%) by horizontal web-building spiders, followed by intermediate (48%) and low (31%) dependence by cursorial and vertical web-building spiders, respectively. The spider body size was negatively correlated with the dietary proportion of aquatic insects and spider {delta}{sup 15}N. The aquatic subsidies transported anthropogenic N to smaller riparian spiders downstream. This transport of anthropogenic N was regulated by spider's guild designation and body size. - Highlights: > {delta}{sup 15}N of aquatic insects increases downstream with anthropogenic nitrogen inputs. > {delta}{sup 15}N of riparian spiders increases with a high dietary proportion of aquatic insects and smaller spider body size. > The aquatic subsidies transport anthropogenic nitrogen to smaller riparian spiders downstream. - Smaller spiders assimilate anthropogenic nitrogen through the predation on aquatic subsides.

  18. Aquatic subsidies transport anthropogenic nitrogen to riparian spiders

    International Nuclear Information System (INIS)

    Akamatsu, Fumikazu; Toda, Hideshige

    2011-01-01

    Stable nitrogen isotopic composition (δ 15 N) of aquatic biota increases with anthropogenic N inputs such as sewage and livestock waste downstream. Increase in δ 15 N of riparian spiders downstream may reflect the anthropogenic pollution exposure through predation on aquatic insects. A two-source mixing model based on stable carbon isotopic composition showed the greatest dependence on aquatic insects (84%) by horizontal web-building spiders, followed by intermediate (48%) and low (31%) dependence by cursorial and vertical web-building spiders, respectively. The spider body size was negatively correlated with the dietary proportion of aquatic insects and spider δ 15 N. The aquatic subsidies transported anthropogenic N to smaller riparian spiders downstream. This transport of anthropogenic N was regulated by spider's guild designation and body size. - Highlights: → δ 15 N of aquatic insects increases downstream with anthropogenic nitrogen inputs. → δ 15 N of riparian spiders increases with a high dietary proportion of aquatic insects and smaller spider body size. → The aquatic subsidies transport anthropogenic nitrogen to smaller riparian spiders downstream. - Smaller spiders assimilate anthropogenic nitrogen through the predation on aquatic subsides.

  19. Niche construction within riparian corridors. Part I: Exploring biogeomorphic feedback windows of three pioneer riparian species (Allier River, France)

    Science.gov (United States)

    Hortobágyi, Borbála; Corenblit, Dov; Steiger, Johannes; Peiry, Jean-Luc

    2018-03-01

    Within riparian corridors, biotic-abiotic feedback mechanisms occur between woody vegetation strongly influenced by hydrogeomorphic constraints (e.g., sediment transport and deposition, shear stress, hydrological variability), fluvial landforms, and morphodynamics, which in turn are modulated by the established vegetation. During field investigations in spring 2015, we studied 16 alluvial bars (e.g., point and lateral bars) within the dynamic riparian corridor of the Allier River (France) to assess the aptitude of three pioneer riparian Salicaceae species (Populus nigra L., Salix purpurea L., and Salix alba L.) to establish and act as ecosystem engineers by trapping sediment and constructing fluvial landforms. Our aim is to empirically identify the preferential establishment area (EA; i.e., the local areas where species become established) and the preferential biogeomorphic feedback window (BFW; i.e., where and to what extent the species and geomorphology interact) of these three species on alluvial bars within a 20-km-long river reach. Our results show that the EA and BFW of all three species vary significantly along the longitudinal profile, i.e., upstream-downstream exposure on the alluvial bars, as well as transversally, i.e., the main hydrological connectivity gradient from the river channel toward the floodplain. In the present-day context of the Allier River, P. nigra is the most abundant species, appearing to act as the main engineer species affecting landform dynamics at the bar scale; S. purpurea is established and acts as an ecosystem engineer at locations on alluvial bars that are most exposed to hydrosedimentary flow dynamics, while S. alba is established on the bar tail close to secondary channels and affects the geomorphology in mixed patches along with P. nigra. Our study highlights the role of functional trait diversity of riparian engineer species in controlling the extent of fluvial landform construction along geomorphic gradients within riparian

  20. Power and Conflict in Adaptive Management: Analyzing the Discourse of Riparian Management on Public Lands

    Directory of Open Access Journals (Sweden)

    Jennifer S. Arnold

    2012-03-01

    Full Text Available Adaptive collaborative management emphasizes stakeholder engagement as a crucial component of resilient social-ecological systems. Collaboration among diverse stakeholders is expected to enhance learning, build social legitimacy for decision making, and establish relationships that support learning and adaptation in the long term. However, simply bringing together diverse stakeholders does not guarantee productive engagement. Using critical discourse analysis, we examined how diverse stakeholders negotiated knowledge and power in a workshop designed to inform adaptive management of riparian livestock grazing on a National Forest in the southwestern USA. Publicly recognized as a successful component of a larger collaborative effort, we found that the workshop effectively brought together diverse participants, yet still restricted dialogue in important ways. Notably, workshop facilitators took on the additional roles of riparian experts and instructors. As they guided workshop participants toward a consensus view of riparian conditions and management recommendations, they used their status as riparian experts to emphasize commonalities with stakeholders supportive of riparian grazing and accentuate differences with stakeholders skeptical of riparian grazing, including some Forest Service staff with power to influence management decisions. Ultimately, the management plan published one year later did not fully adopt the consensus view from the workshop, but rather included and acknowledged a broader diversity of stakeholder perspectives. Our findings suggest that leaders and facilitators of adaptive collaborative management can more effectively manage for productive stakeholder engagement and, thus, social-ecological resilience if they are more tentative in their convictions, more critical of the role of expert knowledge, and more attentive to the knowledge, interests, and power of diverse stakeholders.

  1. GIS applications in riparian management

    Science.gov (United States)

    Carrie Christman; Douglas W. Shaw; Charles L. Spann; Penny Luehring

    1996-01-01

    GIS was used to prioritize watersheds for treatment needs across the USDA Forest Service Southwestern Region. Factors in this analysis included soil condition, riparian habitat, population centers and mining sites.

  2. The evaluation of the effects of buffer thickness and dry density on radionuclides migration in engineered barrier system

    International Nuclear Information System (INIS)

    Kato, Fujitaka; Ishihara, Yoshinao; Makino, Hitoshi; Ishiguro, Katsuhiko

    2000-01-01

    The evaluation of the effects of buffer thickness and dry density, one of the buffer design, on radionuclides migration behavior is important from the viewpoint of performance assessment since they have relation to radionuclides migration retardation. It is also considered to help investigation of buffer design that satisfy both safety and economy to condition of the disposal site, which may be required with development of disposal project in the future. Therefore we have performed a sensitivity analysis used buffer thickness and dry density as parameter and considered their combination in this report. Based on this, we have evaluated the effects of buffer thickness and dry density on radionuclides migration in engineered barrier system. And, we have considered about radionuclides migration retardation quality of the buffer which is based on the design (relationship between thickness and dry density) set in the second progress report on research and development for the geological disposal of HLW in Japan. In results, the maximum release rates from the engineered barrier system for the nuclides which have high distribution coefficients and short half lives are sensitive to changes in buffer thickness and dry density. And, using dose converted from the nuclide release rates from the engineered barrier system as a convenient index, it is almost shown that the maximum of total dose is less than 10 μ Sv/y in the cases which buffer thickness and dry density are based on the buffer design set in the second progress report on research and development for the geological disposal of HLW in Japan. These can be used as an information when design of buffer thickness and dry density is set by synthetically judgement of balance of safety and economy. (author)

  3. Incorporating climate change projections into riparian restoration planning and design

    Science.gov (United States)

    Perry, Laura G.; Reynolds, Lindsay V.; Beechie, Timothy J.; Collins, Mathias J.; Shafroth, Patrick B.

    2015-01-01

    Climate change and associated changes in streamflow may alter riparian habitats substantially in coming decades. Riparian restoration provides opportunities to respond proactively to projected climate change effects, increase riparian ecosystem resilience to climate change, and simultaneously address effects of both climate change and other human disturbances. However, climate change may alter which restoration methods are most effective and which restoration goals can be achieved. Incorporating climate change into riparian restoration planning and design is critical to long-term restoration of desired community composition and ecosystem services. In this review, we discuss and provide examples of how climate change might be incorporated into restoration planning at the key stages of assessing the project context, establishing restoration goals and design criteria, evaluating design alternatives, and monitoring restoration outcomes. Restoration planners have access to numerous tools to predict future climate, streamflow, and riparian ecology at restoration sites. Planners can use those predictions to assess which species or ecosystem services will be most vulnerable under future conditions, and which sites will be most suitable for restoration. To accommodate future climate and streamflow change, planners may need to adjust methods for planting, invasive species control, channel and floodplain reconstruction, and water management. Given the considerable uncertainty in future climate and streamflow projections, riparian ecological responses, and effects on restoration outcomes, planners will need to consider multiple potential future scenarios, implement a variety of restoration methods, design projects with flexibility to adjust to future conditions, and plan to respond adaptively to unexpected change.

  4. Riparian bird density decline in response to biocontrol of Tamarix from riparian ecosystems along the Dolores River in SW Colorado, USA

    Science.gov (United States)

    Darrah, Abigail J.; van Riper, Charles

    2018-01-01

    Biocontrol of invasive tamarisk (Tamarix spp.) in the arid Southwest using the introduced tamarisk beetle (Diorhabda elongata) has been hypothesized to negatively affect some breeding bird species, but no studies to date have documented the effects of beetle-induced defoliation on riparian bird abundance. We assessed the effects of tamarisk defoliation by monitoring defoliation rates, changes in vegetation composition, and changes in density of six obligate riparian breeding bird species at two sites along the Dolores River in Colorado following the arrival of tamarisk beetles. We conducted bird point counts from 2010 to 2014 and modeled bird density as a function of native vegetation density and extent of defoliation using hierarchical distance sampling. Maximum annual defoliation decreased throughout the study period, peaking at 32–37% in 2009–2010 and dropping to 0.5–15% from 2011–2014. Stem density of both tamarisk and native plants declined throughout the study period until 2014. Density of all bird species declined throughout most of the study, with Song Sparrow disappearing from the study sites after 2011. Blue Grosbeak, Yellow-breasted Chat, and Yellow Warbler densities were negatively related to defoliation in the previous year, while Lazuli Bunting exhibited a positive relationship with defoliation. These findings corroborate earlier predictions of species expected to be sensitive to defoliation as a result of nest site selection. Tamarisk defoliation thus had short-term negative impacts on riparian bird species; active restoration may be needed to encourage the regrowth of native riparian vegetation, which in the longer-term may result in increased riparian bird density.

  5. Riparian Cottonwood Ecosystems and Regulated Flows in Kootenai and Yakima Sub-Basins : Volume I Kootenai River (Overview, Report and Appendices).

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, Bob; Braatne, Jeffrey H.

    2001-10-01

    Riparian vegetation and especially cottonwood and willow plant communities are dependent on normative flows and especially, spring freshette, to provide conditions for recruitment. These plant communities therefore share much in common with a range of fish species that require natural flow conditions to stimulate reproduction. We applied tools and techniques developed in other areas to assess riparian vegetation in two very different sub-basins within the Columbia Basin. Our objectives were to: Document the historic impact of human activity on alluvial floodplain areas in both sub-basins; Provide an analysis of the impacts of flow regulation on riparian vegetation in two systems with very different flow regulation systems; Demonstrate that altered spring flows will, in fact, result in recruitment to cottonwood stands, given other land uses impacts on each river and the limitations imposed by other flow requirements; and Assess the applicability of remote sensing tools for documenting the distribution and health of cottonwood stands and riparian vegetation that can be used in other sub-basins.

  6. Explaining landholders' decisions about riparian zone management: the role of behavioural, normative, and control beliefs.

    Science.gov (United States)

    Fielding, Kelly S; Terry, Deborah J; Masser, Barbara M; Bordia, Prashant; Hogg, Michael A

    2005-10-01

    Water quality is a key concern in the current global environment, with the need to promote practices that help to protect water quality, such as riparian zone management, being paramount. The present study used the theory of planned behaviour as a framework for understanding how beliefs influence decisions about riparian zone management. Respondents completed a survey that assessed their behavioural, normative, and control beliefs in relation to intentions to manage riparian zones on their property. The results of the study showed that, overall, landholders with strong intentions to manage their riparian zones differed significantly in terms of their beliefs compared to landholders who had weak intentions to manage their riparian zones. Strong intentions to manage riparian zones were associated with a favourable cost-benefit analysis, greater perceptions of normative support for the practice and lower perceptions of the extent to which barriers would impede management of riparian zones. It was also evident that willingness to comply with the recommendations of salient referents, beliefs about the benefits of riparian zone management and perceptions of the extent to which barriers would impede riparian zone management were most important for determining intentions to manage riparian zones. Implications for policy and extension practice are discussed.

  7. Social Buffering of Stress in Development: A Career Perspective

    Science.gov (United States)

    Gunnar, Megan R.

    2016-01-01

    This review provides a broad overview of my research group's work on social buffering in human development in the context of the field. Much of the focus is on social buffering of the hypothalamic-pituitary-adrenocortical (HPA) system, one of the two major arms of the mammalian stress system. This focus reflects the centrality of the HPA system in research on social buffering in the fields of developmental psychobiology and developmental science. However, buffering of the cardiovascular and autonomic nervous system is also discussed. The central developmental question in this area derives from attachment theory which argues that the infant's experience of stress and arousal regulation in the context of her early attachment relationships is not an immature form of social buffering experienced in adulthood, but rather the foundation out of which individual differences in the capacity to gain stress relief from social partners emerge. The emergence of social buffering in infancy, changes in social buffering throughout childhood and adolescence, the influence of early experience on later individual differences in social buffering, and critical gaps in our knowledge are described. PMID:28544861

  8. The Irrigation Effect: How River Regulation Can Promote Some Riparian Vegetation

    Science.gov (United States)

    Gill, Karen M.; Goater, Lori A.; Braatne, Jeffrey H.; Rood, Stewart B.

    2018-04-01

    River regulation impacts riparian ecosystems by altering the hydrogeomorphic conditions that support streamside vegetation. Obligate riparian plants are often negatively impacted since they are ecological specialists with particular instream flow requirements. Conversely, facultative riparian plants are generalists and may be less vulnerable to river regulation, and could benefit from augmented flows that reduce drought stress during hot and dry periods. To consider this `irrigation effect' we studied the facultative shrub, netleaf hackberry ( Celtis reticulata), the predominant riparian plant along the Hells Canyon corridor of the Snake River, Idaho, USA, where dams produce hydropeaking, diurnal flow variation. Inventories of 235 cross-sectional transects revealed that hackberry was uncommon upstream from the reservoirs, sparse along the reservoir with seasonal draw-down and common along two reservoirs with stabilized water levels. Along the Snake River downstream, hackberry occurred in fairly continuous, dense bands along the high water line. In contrast, hackberry was sparsely scattered along the free-flowing Salmon River, where sandbar willow ( Salix exigua), an obligate riparian shrub, was abundant. Below the confluence of the Snake and Salmon rivers, the abundance and distribution of hackberry were intermediate between the two upstream reaches. Thus, river regulation apparently benefited hackberry along the Snake River through Hells Canyon, probably due to diurnal pulsing that wets the riparian margin. We predict similar benefits for some other facultative riparian plants along other regulated rivers with hydropeaking during warm and dry intervals. To analyze the ecological impacts of hydropeaking we recommend assessing daily maxima, as well as daily mean river flows.

  9. Internal Active Thermal Control System (IATCS) Sodium Bicarbonate/Carbonate Buffer in an Open Aqueous Carbon Dioxide System and Corollary Electrochemical/Chemical Reactions Relative to System pH Changes

    Science.gov (United States)

    Stegman, Thomas W.; Wilson, Mark E.; Glasscock, Brad; Holt, Mike

    2014-01-01

    The International Space Station (ISS) Internal Active Thermal Control System (IATCS) experienced a number of chemical changes driven by system absorption of CO2 which altered the coolant’s pH. The natural effects of the decrease in pH from approximately 9.2 to less than 8.4 had immediate consequences on system corrosion rates and corrosion product interactions with specified coolant constituents. The alkalinity of the system was increased through the development and implementation of a carbonate/bicarbonate buffer that would increase coolant pH to 9.0 – 10.0 and maintain pH above 9.0 in the presence of ISS cabin concentrations of CO2 up to twenty times higher than ground concentrations. This paper defines how a carbonate/bicarbonate buffer works in an open carbon dioxide system and summarizes the analyses performed on the buffer for safe and effective application in the on-orbit system. The importance of the relationship between the cabin environment and the IATCS is demonstrated as the dominant factor in understanding the system chemistry and pH trends before and after addition of the carbonate/bicarbonate buffer. The paper also documents the corollary electrochemical and chemical reactions the system has experienced and the rationale for remediation of these effects with the addition of the carbonate/bicarbonate buffer.

  10. Riparian Habitat - San Joaquin River

    Data.gov (United States)

    California Natural Resource Agency — The immediate focus of this study is to identify, describe and map the extent and diversity of riparian habitats found along the main stem of the San Joaquin River,...

  11. Restoration ecology and invasive riparian plants: An introduction to the special section on Tamarix spp. in western North America

    Science.gov (United States)

    Shafroth, Patrick B.; Briggs, Mark K.

    2008-01-01

    River systems around the world are subject to various perturbations, including the colonization and spread of non-native species in riparian zones. Riparian resource managers are commonly engaged in efforts to control problematic non-native species and restore native habitats. In western North America, small Eurasian trees or shrubs in the genus Tamarixoccupy hundreds of thousands of hectares of riparian lands, and are the targets of substantial and costly control efforts and associated restoration activities. Still, significant information gaps exist regarding approaches used in control and restoration efforts and their effects on riparian ecosystems. In this special section of papers, eight articles address various aspects of control and restoration associated with Tamarix spp. These include articles focused on planning restoration and revegetation; a synthetic analysis of past restoration efforts; and several specific research endeavors examining plant responses, water use, and various wildlife responses (including birds, butterflies, and lizards). These articles represent important additions to the Tamarix spp. literature and contain many lessons and insights that should be transferable to other analogous situations in river systems globally.

  12. The adsorption/desorption of phosphorus in freshwater sediments from buffer zones: the effects of sediment concentration and pH.

    Science.gov (United States)

    Zhang, Liang; Du, Yun; Du, Chao; Xu, Meng; Loáiciga, Hugo A

    2016-01-01

    Riparian buffer zones adjacent to reservoirs and lakes protect aquatic ecosystems from polluted surface runoff. Sediments, collected from the buffer zones of Danjiangkou Reservoir (SR) and Honghu Lake (SL) in an ecologically fragile region in central China, were evaluated to reveal their phosphorus-adsorbing/desorbing properties and storage capacities. A nonlinear regression method was used to fit the pseudo-second-order kinetic and the modified crossover-type Langmuir isotherm models to the experimental data. It is shown that the adsorption of phosphorus onto the studied sediments followed the pseudo-second-order kinetic expression. The modified crossover-type Langmuir isotherm model was found to be a suitable method for describing adsorption/desorption processes in the experimental sediments. The maximum adsorption capacities (Q m), partitioning coefficients (K p), native adsorbed exchangeable phosphorus (NAP), and equilibrium phosphorus concentration (EPC0) were subsequently obtained for the experimental sediments. The effects of sediment concentration and pH were also investigated by batch experiments and Fourier transformation infrared and scanning electron microscopy analyses. The adsorption/desorption characteristics of different phosphate species on the sediments from reservoir and lake buffer zones were identified.

  13. Multiscale remote sensing analysis to monitor riparian and upland semiarid vegetation

    Science.gov (United States)

    Nguyen, Uyen

    to estimate the effects of vegetation, land use patterns and water cycles. Climate change, hydrological and human uses are also leading to riparian, upland, grassland and crop vegetation changes at a variety of temporal and spatial scales, particularly in the arid and semi arid ecosystems, which are more sensitive to changes in water availability than humid ecosystems. The objectives of these studies from the last three articles were to evaluate the effect of water balance on vegetation indices in different plant communities based on relevant spatial and temporal scales. The new methodology of estimating water requirements using remote sensing data and ground calibration with flux tower data has been successfully tested at a variety sites, a sparse desert shrub environment as well as mixed riparian and cropland systems and upland vegetation in the arid and semi-arid regions. The main finding form these studies is that vegetation-index methods have to be calibrated with ground data for each new ecosystem but once calibrated they can accurately scale ET over wide areas and long time spans.

  14. RELATIONSHIPS AMONG GEOMORPHOLOGY, HYDROLOGY, AND VEGETATION IN RIPARIAN MEADOWS: RESTORATION IMPLICATIONS

    Science.gov (United States)

    Vegetation patterns and dynamics within riparian corridors are controlled largely by geomorphic position, substrate characteristics and hydrologic regimes. Understanding management and restoration options for riparian meadow complexes exhibiting stream incision requires knowledge...

  15. Modeling the evolution of riparian woodlands facing climate change in three European rivers with contrasting flow regimes.

    Directory of Open Access Journals (Sweden)

    Rui P Rivaes

    Full Text Available Global circulation models forecasts indicate a future temperature and rainfall pattern modification worldwide. Such phenomena will become particularly evident in Europe where climate modifications could be more severe than the average change at the global level. As such, river flow regimes are expected to change, with resultant impacts on aquatic and riparian ecosystems. Riparian woodlands are among the most endangered ecosystems on earth and provide vital services to interconnected ecosystems and human societies. However, they have not been the object of many studies designed to spatially and temporally quantify how these ecosystems will react to climate change-induced flow regimes. Our goal was to assess the effects of climate-changed flow regimes on the existing riparian vegetation of three different European flow regimes. Cases studies were selected in the light of the most common watershed alimentation modes occurring across European regions, with the objective of appraising expected alterations in the riparian elements of fluvial systems due to climate change. Riparian vegetation modeling was performed using the CASiMiR-vegetation model, which bases its computation on the fluvial disturbance of the riparian patch mosaic. Modeling results show that riparian woodlands may undergo not only at least moderate changes for all flow regimes, but also some dramatic adjustments in specific areas of particular vegetation development stages. There are circumstances in which complete annihilation is feasible. Pluvial flow regimes, like the ones in southern European rivers, are those likely to experience more pronounced changes. Furthermore, regardless of the flow regime, younger and more water-dependent individuals are expected to be the most affected by climate change.

  16. Effects of changes in the riparian forest on the butterfly community (Insecta: Lepidoptera in Cerrado areas

    Directory of Open Access Journals (Sweden)

    Helena S.R. Cabette

    Full Text Available ABSTRACT Preserved riparian vegetation usually has greater environmental complexity than the riparian vegetation modified by human actions. These systems may have a greater availability and diversity of food resources for the species. Our objective was to evaluate the effect of changes on the structure of the riparian forest on species richness, beta diversity and composition of butterfly species in the Cerrado of Mato Grosso. We tested the hypotheses that: (i higher species richness and (ii beta diversity would be recorded in more preserved environments; and (iii species composition would be more homogeneous in disturbed habitats. For hypothesis testing, the riparian vegetation of eight streams were sampled in four periods of the year in a fixed transect of 100 m along the shores. The richness of butterfly species is lower in disturbed than in preserved areas. However, species richness is not affected by habitat integrity. Beta diversity differed among sites, such that preserved sites have greater beta diversity, showing greater variation in species composition. In addition, beta diversity was positively affected by environmental heterogeneity. A total of 23 of the 84 species sampled occurred only in the changed environment, 42 were exclusive to preserved sites and 19 occurred in both environments. The environmental change caused by riparian forest removal drastically affects the butterfly community. Therefore, riparian vegetation is extremely important for butterfly preservation in the Cerrado and may be a true biodiversity oasis, especially during the dry periods, when the biome undergoes water stress and resource supply is more limited.

  17. Assessing Riparian Vegetation Condition and Function in Disturbed Sites of the Arid Northwestern Mexico

    Directory of Open Access Journals (Sweden)

    Lara Cornejo-Denman

    2018-01-01

    Full Text Available Transformation or modification of vegetation distribution and structure in arid riparian ecosystems can lead to the loss of ecological function. Mexico has 101,500,000 ha of arid lands, however there is a general lack of information regarding how arid riparian ecosystems are being modified. To assess these modifications, we use eight sites in the San Miguel River (central Sonora to analyze (1 riparian vegetation composition, structure and distribution using field sampling and remote sensing data from Unmanned Aerial Vehicles (UAV; (2 productivity (proxies, using vegetation indices derived from satellite data; and (3 variability posed by riparian vegetation and vegetation adjacent to riparian habitats. The development of a simple yet informative Anthropogenic-disturbance Index (ADI allowed us to classify and describe each study site. We found sharp differences in vegetation composition and structure between sites due to the absence/presence of obligate-riparian species. We also report significant difference between EVI (Enhanced Vegetation Index values for the dry season among vegetation types that develop near the edges of the river but differ in composition, suggesting that land cover changes form obligate-riparian to facultative-riparian species can lead to a loss in potential productivity. Finally, our tests suggest that sites with higher disturbance present lower photosynthetic activity.

  18. Monoclonal antibody heterogeneity analysis and deamidation monitoring with high-performance cation-exchange chromatofocusing using simple, two component buffer systems.

    Science.gov (United States)

    Kang, Xuezhen; Kutzko, Joseph P; Hayes, Michael L; Frey, Douglas D

    2013-03-29

    The use of either a polyampholyte buffer or a simple buffer system for the high-performance cation-exchange chromatofocusing of monoclonal antibodies is demonstrated for the case where the pH gradient is produced entirely inside the column and with no external mixing of buffers. The simple buffer system used was composed of two buffering species, one which becomes adsorbed onto the column packing and one which does not adsorb, together with an adsorbed ion that does not participate in acid-base equilibrium. The method which employs the simple buffer system is capable of producing a gradual pH gradient in the neutral to acidic pH range that can be adjusted by proper selection of the starting and ending pH values for the gradient as well as the buffering species concentration, pKa, and molecular size. By using this approach, variants of representative monoclonal antibodies with isoelectric points of 7.0 or less were separated with high resolution so that the approach can serve as a complementary alternative to isoelectric focusing for characterizing a monoclonal antibody based on differences in the isoelectric points of the variants present. Because the simple buffer system used eliminates the use of polyampholytes, the method is suitable for antibody heterogeneity analysis coupled with mass spectrometry. The method can also be used at the preparative scale to collect highly purified isoelectric variants of an antibody for further study. To illustrate this, a single isoelectric point variant of a monoclonal antibody was collected and used for a stability study under forced deamidation conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Characterisation of the impacts of pre- and post- remedial contaminant loads from the Rum Jungle on riparian vegetation and fishes of the Finniss River system

    International Nuclear Information System (INIS)

    Jeffree, R.A.

    2002-01-01

    The status of the riparian vegetation and fish biodiversity in the Finniss River (FR) system is compared before and after remediation at the Rum Jungle (RJ) mine site. Whereas observations recorded during pre-remedial field studies in 1974 indicate no obvious effects of mine effluents on the riparian vegetation in the FR, the impacts in the Eeast Branch were severe. The tolerance to Cu that has been measured in one fish species (Gale et al., submitted) suggests the possibility that the exposure of the fish community to contaminant loadings over more than four decades may have led to the development of tolerance that may also contribute to the ecological recovery that has been observed

  20. Passive reestablishment of riparian vegetation following removal of invasive knotweed (Polygonum)

    Science.gov (United States)

    Shannon M. Claeson; Peter A. Bisson

    2013-01-01

    Japanese knotweed and congeners are invasive to North America and Europe and spread aggressively along rivers establishing dense monotypic stands, thereby reducing native riparian plant diversity, structure, and function. Noxious weed control programs attempt to eradicate the knotweed with repeated herbicide applications under the assumption that the system will...

  1. Analysis of diffusive mass transport in a cracked buffer

    International Nuclear Information System (INIS)

    Garisto, N.C.; Garisto, F.

    1989-11-01

    In the disposal vault design for the Canadian Nuclear Fuel Waste Management Program, cylindrical containers of used nuclear fuel would be placed in vertical boreholes in rock and surrounded with a bentonite-based buffer material. The buffer is expected to absorb and/or retard radionuclides leaching from the fuel after the containers fail. There is some evidence, however, that the buffer may be susceptible to cracking. In this report we investigate numerically the consequences of cracking on uranium diffusion through the buffer. The derivation of the mass-transport equations and the numerical solution method are presented for the solubility-limited diffusion of uranium in a cracked buffer system for both swept-away and semi-impermeable boundary conditions at the rock-buffer interface. The results indicate that for swept-away boundary conditions the total uranium flux through the cracked buffer system is, as expected, greater than through the uncracked buffer. The effect of the cracks is strongly dependent on the ratio D/D eff , where D and D eff are the pore-water and the effective buffer diffusion coefficient, respectively. However, although a decrease in D eff enhances the effect of cracks on the total cumulative flux (relative to the uncracked buffer), it also decreases the total cumulative flux through the cracked buffer system (relative to a cracked buffer with a larger D eff value). Finally, for semi-impermeable boundary conditions, the effect of cracks on the total radionuclide flux is relatively small

  2. Importance of riparian remnants for frog species diversity in a highly fragmented rainforest.

    Science.gov (United States)

    Rodríguez-Mendoza, Clara; Pineda, Eduardo

    2010-12-23

    Tropical forests undergo continuous transformation to other land uses, resulting in landscapes typified by forest fragments surrounded by anthropogenic habitats. Small forest fragments, specifically strip-shaped remnants flanking streams (referred to as riparian remnants), can be particularly important for the maintenance and conservation of biodiversity within highly fragmented forests. We compared frog species diversity between riparian remnants, other forest fragments and cattle pastures in a tropical landscape in Los Tuxtlas, Mexico. We found similar species richness in the three habitats studied and a similar assemblage structure between riparian remnants and forest fragments, although species composition differed by 50 per cent. Frog abundance was halved in riparian remnants compared with forest fragments, but was twice that found in pastures. Our results suggest that riparian remnants play an important role in maintaining a portion of frog species diversity in a highly fragmented forest, particularly during environmentally stressful (hot and dry) periods. In this regard, however, the role of riparian remnants is complementary, rather than substitutive, with respect to the function of other forest fragments within the fragmented forest.

  3. 2011 Los Alamos National Laboratory Riparian Inventory Results

    Energy Technology Data Exchange (ETDEWEB)

    Norris, Elizabeth J. [Los Alamos National Laboratory; Hansen, Leslie A. [Los Alamos National Laboratory; Hathcock, Charles D. [Los Alamos National Laboratory; Keller, David C. [Los Alamos National Laboratory; Zemlick, Catherine M. [Los Alamos National Laboratory

    2012-03-29

    A total length of 36.7 kilometers of riparian habitat were inventoried within LANL boundaries between 2007 and 2011. The following canyons and lengths of riparian habitat were surveyed and inventoried between 2007 and 2011. Water Canyon (9,669 m), Los Alamos Canyon (7,131 m), Pajarito Canyon (6,009 m), Mortandad Canyon (3,110 m), Two-Mile Canyon (2,680 m), Sandia Canyon (2,181 m), Three-Mile Canyon (1,883 m), Canyon de Valle (1,835 m), Ancho Canyon (1,143 m), Canada del Buey (700 m), Sandia Canyon (221 m), DP Canyon (159 m) and Chaquehui Canyon (50 m). Effluent Canyon, Fence Canyon and Potrillo Canyon were surveyed but no areas of riparian habitat were found. Stretches of inventoried riparian habitat were classified for prioritization of treatment, if any was recommended. High priority sites included stretches of Mortandad Canyon, LA Canyon, Pajarito Canyon, Two-Mile Canyon, Sandia Canyon and Water Canyon. Recommended treatment for high priority sites includes placement of objects into the stream channel to encourage sediment deposition, elimination of channel incision, and to expand and slow water flow across the floodplain. Additional stretches were classified as lower priority, and, for other sites it was recommended that feral cattle and exotic plants be removed to aid in riparian habitat recovery. In June 2011 the Las Conchas Wildfire burned over 150,000 acres of land in the Jemez Mountains and surrounding areas. The watersheds above LA Canyon, Water Canyon and Pajarito Canyon were burned in the Las Conchas Wildfire and flooding and habitat alteration were observed in these canyon bottoms (Wright 2011). Post fire status of lower priority areas may change to higher priority for some of the sites surveyed prior to the Las Conchas Wildfire, due to changes in vegetation cover in the adjacent upland watershed.

  4. Evapotranspiration Rates of Riparian Forests, Platte River, Nebraska, 2002-06

    Science.gov (United States)

    Landon, Matthew K.; Rus, David L.; Dietsch, Benjamin J.; Johnson, Michaela R.; Eggemeyer, Kathleen D.

    2009-01-01

    Evapotranspiration (ET) in riparian areas is a poorly understood component of the regional water balance in the Platte River Basin, where competing demands have resulted in water shortages in the ground-water/surface-water system. From April 2002 through March 2006, the U.S. Geological Survey, Nebraska Platte River Cooperative Hydrology Study Group, and Central Platte Natural Resources District conducted a micrometeorological study of water and energy balances at two sites in central Nebraska near Odessa and Gothenburg to improve understanding of ET rates and factors affecting them in Platte River riparian forests. A secondary objective of the study was to constrain estimates of ground-water use by riparian vegetation to satisfy ET consumptive demands, a useful input to regional ground-water flow models. Both study sites are located on large islands within the Platte River characterized by a cottonwood-dominated forest canopy on primarily sandy alluvium. Although both sites are typical of riparian forests along the Platte River in Nebraska, the Odessa understory is dominated by deciduous shrubs, whereas the Gothenburg understory is dominated by eastern redcedars. Additionally, seasonal ground-water levels fluctuated more at Odessa than at Gothenburg. The study period of April 2002 through March 2006 encompassed precipitation conditions ranging from dry to wet. This study characterized the components of the water balance in the riparian zone of each site. ET was evaluated from eddy-covariance sensors installed on towers above the forest canopy at a height of 26.1 meters. Precipitation was measured both above and below the forest canopy. A series of sensors measured soil-moisture availability within the unsaturated zone in two different vertical profiles at each site. Changes in ground-water altitude were evaluated from piezometers. The areal footprint represented in the water balance extended up to 800 meters from each tower. During the study, ET was less variable

  5. Monitoring and mapping selected riparian habitat along the lower Snake River

    Energy Technology Data Exchange (ETDEWEB)

    Downs, J. L; Tiller, B. L [Pacific Northwest Lab., Richland, WA (United States); Witter, M. [Shannon and Wilson, Inc., Seattle, WA (United States). Geotechnical and Environmental Consultants, Seattle, Washington (United States); Mazaika, R. [Corps of Engineers, Portland, OR (United States)

    1996-01-01

    Studies in this document were initiated to establish baseline information on riparian and wetland habitat conditions at the areas studied under the current reservoir operations on the lower Snake River. Two approaches were used to assess habitat at 28 study sites selected on the four pools on the lower Snake River. These areas all contribute significant riparian habitat along the river, and several of these areas are designated habitat management units. At 14 of the 28 sites, we monitored riparian habitat on three dates during the growing season to quantify vegetation abundance and composition along three transects: soil nutrients, moisture, and pH and water level and pH. A second approach involved identifying any differences in the extent and amount of riparian/wetland habitat currently found at the study areas from that previously documented. We used both ground and boat surveys to map and classify the changes in vegetative cover along the shoreline at the 14 monitoring sites and at 14 additional sites along the lower Snake selected to represent various riparian/wetland habitat conditions. Results of these mapping efforts are compared with maps of cover types previously generated using aerial photography taken in 1987.

  6. Riparian Meadow Response to Modern Conservation Grazing Management

    Science.gov (United States)

    Oles, Kristin M.; Weixelman, Dave A.; Lile, David F.; Tate, Kenneth W.; Snell, Laura K.; Roche, Leslie M.

    2017-09-01

    Riparian meadows occupy a small proportion of the public lands in the western United States but they provide numerous ecosystem services, including the production of high-quality forage for livestock grazing. Modern conservation management strategies (e.g., reductions in livestock stocking rates and adoption of new riparian grazing standards) have been implemented to better balance riparian conservation and livestock production objectives on publicly managed lands. We examined potential relationships between long-term changes in plant community, livestock grazing pressure and environmental conditions at two spatial scales in meadows grazed under conservation management strategies. Changes in plant community were not associated with either livestock stocking rate or precipitation at the grazing allotment (i.e., administrative) scale. Alternatively, both grazing pressure and precipitation had significant, albeit modest, associations with changes in plant community at the meadow (i.e., ecological site) scale. These results suggest that reductions in stocking rate have improved the balance between riparian conservation and livestock production goals. However, associations between elevation, site wetness, precipitation, and changes in plant community suggest that changing climate conditions (e.g., reduced snowpack and changes in timing of snowmelt) could trigger shifts in plant communities, potentially impacting both conservation and agricultural services (e.g., livestock and forage production). Therefore, adaptive, site-specific management strategies are required to meet grazing pressure limits and safeguard ecosystem services within individual meadows, especially under more variable climate conditions.

  7. Low noise buffer amplifiers and buffered phase comparators for precise time and frequency measurement and distribution

    Science.gov (United States)

    Eichinger, R. A.; Dachel, P.; Miller, W. H.; Ingold, J. S.

    1982-01-01

    Extremely low noise, high performance, wideband buffer amplifiers and buffered phase comparators were developed. These buffer amplifiers are designed to distribute reference frequencies from 30 KHz to 45 MHz from a hydrogen maser without degrading the hydrogen maser's performance. The buffered phase comparators are designed to intercompare the phase of state of the art hydrogen masers without adding any significant measurement system noise. These devices have a 27 femtosecond phase stability floor and are stable to better than one picosecond for long periods of time. Their temperature coefficient is less than one picosecond per degree C, and they have shown virtually no voltage coefficients.

  8. Landscape-scale processes influence riparian plant composition along a regulated river

    Science.gov (United States)

    Palmquist, Emily C.; Ralston, Barbara; Merritt, David M.; Shafroth, Patrick B.

    2018-01-01

    Hierarchical frameworks are useful constructs when exploring landscape- and local-scale factors affecting patterns of vegetation in riparian areas. In drylands, which have steep environmental gradients and high habitat heterogeneity, landscape-scale variables, such as climate, can change rapidly along a river's course, affecting the relative influence of environmental variables at different scales. To assess how landscape-scale factors change the structure of riparian vegetation, we measured riparian vegetation composition along the Colorado River through Grand Canyon, determined which factors best explain observed changes, identified how richness and functional diversity vary, and described the implications of our results for river management. Cluster analysis identified three divergent floristic groups that are distributed longitudinally along the river. These groups were distributed along gradients of elevation, temperature and seasonal precipitation, but were not associated with annual precipitation or local-scale factors. Species richness and functional diversity decreased as a function of distance downstream showing that changing landscape-scale factors result in changes to ecosystem characteristics. Species composition and distribution remain closely linked to seasonal precipitation and temperature. These patterns in floristic composition in a semiarid system inform management and provide insights into potential future changes as a result of shifts in climate and changes in flow management.

  9. Conservation of filtering in manufacturing systems with unreliable machines and finished goods buffers

    Directory of Open Access Journals (Sweden)

    Jingshan Li

    2006-01-01

    nature of manufacturing systems, this law offers a tool for selecting the smallest, that is, lean, finished goods buffering, which is necessary and sufficient to ensure the desired level ofcustomer demand satisfaction.

  10. Riparian adaptive management symposium: a conversation between scientists and management

    Science.gov (United States)

    Douglas F. Ryan; John M. Calhoun

    2010-01-01

    Scientists, land managers and policy makers discussed whether riparian (stream side) forest management and policy for state, federal and private lands in western Washington are consistent with current science. Answers were mixed: some aspects of riparian policy and management have a strong basis in current science, while other aspects may not. Participants agreed that...

  11. A framework for profiling a lake's riparian area development potential

    Science.gov (United States)

    Pamela J. Jakes; Ciara Schlichting; Dorothy H. Anderson

    2003-01-01

    Some of the greatest challenges for managing residential development occur at the interface between the terrestrial and aquatic ecosystems -in a lake`s riparian area. Land use planners need a framework they can use to identify development hotspots, areas were the next push for development will most likely occur. Lake riparian development profiles provide a framework...

  12. Population and Habitat Objectives for Avian Conservation in California's Central Valley Riparian Ecosystems

    Directory of Open Access Journals (Sweden)

    Kristen E. Dybala

    2017-03-01

    Full Text Available https://doi.org/10.15447/sfews.2017v15iss1art5Riparian ecosystems provide important ecosystem services and recreational opportunities for people, and habitat for wildlife. In California’s Central Valley, government agencies and private organizations are working together to protect and restore riparian ecosystems, and the Central Valley Joint Venture provides leadership in the formulation of goals and objectives for avian conservation in riparian ecosystems. We defined a long-term conservation goal as the establishment of riparian ecosystems that provide sufficient habitat to support genetically robust, self-sustaining, and resilient bird populations. To achieve this goal, we selected a suite of 12 breeding riparian landbird focal species as indicators of the state of riparian ecosystems in each of four major Central Valley planning regions. Using recent bird survey data, we estimated that over half of the regional focal species populations are currently small (< 10,000 and may be vulnerable to extirpation, and two species have steeply declining population trends. For each focal species in each region, we defined long-term (100-year population objectives that are intended to be conservation endpoints that we expect to meet the goal of genetically robust, self-sustaining, and resilient populations. We then estimated the long-term species density and riparian restoration objectives required to achieve the long-term population objectives. To track progress toward the long-term objectives, we propose short-term (10- year objectives, including the addition of 12,919 ha (31,923 ac of riparian vegetation in the Central Valley (by planning region: 3,390 ha in Sacramento, 2,390 ha in Yolo–Delta, 3,386 ha in San Joaquin, and 3,753 ha in Tulare. We expect that reaching these population, density, and habitat objectives through threat abatement, habitat restoration, and habitat enhancement will result in improvements to riparian ecosystem function and

  13. Buffer construction technique using granular bentonite

    International Nuclear Information System (INIS)

    Masuda, Ryoichi; Asano, Hidekazu; Toguri, Satohito; Mori, Takuo; Shimura, Tomoyuki; Matsuda, Takeshi; Uyama, Masao; Noda, Masaru

    2007-01-01

    Buffer construction using bentonite pellets as filling material is a promising technology for enhancing the ease of repository operation. In this study, a test of such technology was conducted in a full-scale simulated disposal drift, using a filling system which utilizes a screw conveyor system. The simulated drift, which contained two dummy overpacks, was configured as a half-cross-section model with a height of 2.22 m and a length of 6.0 m. The average dry density of the buffer obtained in the test was 1.29 Mg/m 3 , with an angle of repose of 35 to 40 degrees. These test results indicate that buffer construction using a screw conveyor system for pellet emplacement in a waste disposal drift is a promising technology for repositories for high level radioactive wastes. (author)

  14. Community Structure of Riparian Community of Sematang Borang River of South Sumatera

    Directory of Open Access Journals (Sweden)

    Yetty Hastiana

    2015-12-01

    Full Text Available Vegetasi riparian adalah sebagai ekoton antara habitat teresterial dengan sistem perairan (sungai. Penyangga riparian berfungsi untuk menjaga kelestarian fungsi sungai dengan cara menahan atau menangkap tanah (lumpur yang tererosi serta unsur hara dan bahan kimia termasuk pestisida yang terbawa dari lahan dibagian kiri kanan sungai agar tidak masuk ke perairan. Sungai Sematang Borang merupakan bagian dari Daerah Aliran Sungai (DAS Musi, Sungai Sematang Borang memiliki karaketeristik struktur sungai dengan panjang seitar 5 km, lebar sungai mencapai 70 m dan kedalaman sekitar 10 m. Saat ini sungai ini mulai terancam mengalami penurunan kualitas baik fisik, kimia maupun biologi Selain kehilangan habitat alami ikan yang akan berdampak pada penurunan kelimpahan dan biodiversity, perairan ini juga mengalami abrasi pada sisi kiri kanan tebing sungai. Keberadaan vegetasi riparian menjadi penting, selain untuk mencegah abrasi, juga berperan dalam produksi serasah. Produksi serasah berkontribusi dalam transfer bahan organik vegetasi ke dalam tanah. Unsur hara yang dhasilkan dari proses dekomposisi serasah dalam tanah sangat penting bagi kelangsungan hidup vegetasi dan sebagai sumber detritus bagi ekosistem dalam menyokong kehidupan organisme akuatik. Pentingnya kontribusi vegetasi riparian dalam suatu ekosistem, maka perlu dilakukan penelitian terhadap diversitas dan profil vegetasi. Kajian aspek vegetasi, diperkuat dengan melakukan pengamatan terhadap kondisi fisik kimia perairan Sematang Borang. Parameter fisik kimiaperairan yang diamati meliputi: suhu, kedalaman, kecepatan arus, COD, BOD, DO, pH, dan Salinitas. Penelitian menerapkan metode ekologi deskriptif kuantitatif dan kualitatif, untuk analisis kualitas fisik kimia perairan didukung analisis laboratorium dan survei. Hasil penelitian teridentifikasi 15 species riparian dengan kategori indeks keanekaragaman riparian 0,09-1,03 dan memiliki pola penyebaran cenderung berkelompok

  15. Complexation of buffer constituents with neutral complexation agents: part I. Impact on common buffer properties.

    Science.gov (United States)

    Riesová, Martina; Svobodová, Jana; Tošner, Zdeněk; Beneš, Martin; Tesařová, Eva; Gaš, Bohuslav

    2013-09-17

    The complexation of buffer constituents with the complexation agent present in the solution can very significantly influence the buffer properties, such as pH, ionic strength, or conductivity. These parameters are often crucial for selection of the separation conditions in capillary electrophoresis or high-pressure liquid chromatography (HPLC) and can significantly affect results of separation, particularly for capillary electrophoresis as shown in Part II of this paper series (Beneš, M.; Riesová, M.; Svobodová, J.; Tesařová, E.; Dubský, P.; Gaš, B. Anal. Chem. 2013, DOI: 10.1021/ac401381d). In this paper, the impact of complexation of buffer constituents with a neutral complexation agent is demonstrated theoretically as well as experimentally for the model buffer system composed of benzoic acid/LiOH or common buffers (e.g., CHES/LiOH, TAPS/LiOH, Tricine/LiOH, MOPS/LiOH, MES/LiOH, and acetic acid/LiOH). Cyclodextrins as common chiral selectors were used as model complexation agents. We were not only able to demonstrate substantial changes of pH but also to predict the general complexation characteristics of selected compounds. Because of the zwitterion character of the common buffer constituents, their charged forms complex stronger with cyclodextrins than the neutral ones do. This was fully proven by NMR measurements. Additionally complexation constants of both forms of selected compounds were determined by NMR and affinity capillary electrophoresis with a very good agreement of obtained values. These data were advantageously used for the theoretical descriptions of variations in pH, depending on the composition and concentration of the buffer. Theoretical predictions were shown to be a useful tool for deriving some general rules and laws for complexing systems.

  16. Bat activity following restoration prescribed burning in the central Appalachian Upland and riparian habitats

    Science.gov (United States)

    Austin, Lauren V.; Silvis, Alexander; Ford, W. Mark; Muthersbaugh, Michael; Powers, Karen E.

    2018-01-01

    After decades of fire suppression in eastern North America, land managers now are prioritizing prescribed fire as a management tool to restore or maintain fire-adapted vegetation communities. However, in long—fire-suppressed landscapes, such as the central and southern Appalachians, it is unknown how bats will respond to prescribed fire in both riparian and upland forest habitats. To address these concerns, we conducted zero-crossing acoustic surveys of bat activity in burned, unburned, riparian, and non-riparian areas in the central Appalachians, Virginia, USA. Burn and riparian variables had model support (ΔAICc fire differently between upland and riparian forest habitats, but overall, large landscape-level prescribed fire has a slightly positive to neutral impact on all bats species identified at our study site post—fire application.

  17. Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range

    Science.gov (United States)

    Hagar, Joan C.; Li, Judith; Sobota, Janel; Jenkins, Stephanie

    2012-01-01

    Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability. Because distinct vegetation may distinguish riparian from upland habitats for riparian-associated birds and their terrestrial arthropod prey, we suggest that understory communities be considered when defining management zones for riparian habitat.

  18. Butterfly (Papilionoidea and Hesperioidea) assemblages associated with natural, exotic, and restored riparian habitats along the lower Colorado River, USA

    Science.gov (United States)

    Nelson, S.M.; Andersen, D.C.

    1999-01-01

    Butterfly assemblages were used to compare revegetated and natural riparian areas along the lower Colorado River. Species richness and correspondence analyses of assemblages showed that revegetated sites had fewer biological elements than more natural sites along the Bill Williams River. Data suggest that revegetated sites do not provide resources needed by some members of the butterfly assemblage, especially those species historically associated with the cottonwood/willow ecosystem. Revegetated sites generally lacked nectar resources, larval host plants, and closed canopies. The riparian system along the regulated river segment that contains these small revegetated sites also appears to have diminished habitat heterogeneity and uncoupled riparian corridors.Revegetated sites were static environments without the successional stages caused by flooding disturbance found in more natural systems. We hypothesize that revegetation coupled with a more natural hydrology is important for restoration of butterfly assemblages along the lower Colorado River. 

  19. A Buffer Management Issue in Designing SSDs for LFSs

    Science.gov (United States)

    Kim, Jaegeuk; Seol, Jinho; Maeng, Seungryoul

    This letter introduces a buffer management issue in designing SSDs for log-structured file systems (LFSs). We implemented a novel trace-driven SSD simulator in SystemC language, and simulated several SSD architectures with the NILFS2 trace. From the results, we give two major considerations related to the buffer management as follows. (1) The write buffer is used as a buffer not a cache, since all write requests are sequential in NILFS2. (2) For better performance, the main architectural factor is the bus bandwidth, but 332MHz is enough. Instead, the read buffer makes a key role in performance improvement while caching data. To enhance SSDs, accordingly, it is an effective way to make efficient read buffer management policies, and one of the examples is tracking the valid data zone in NILFS2, which can increase the data hit ratio in read buffers significantly.

  20. Favorable fragmentation: river reservoirs can impede downstream expansion of riparian weeds.

    Science.gov (United States)

    Rood, Stewart B; Braatne, Jeffrey H; Goater, Lori A

    2010-09-01

    River valleys represent biologically rich corridors characterized by natural disturbances that create moist and barren sites suitable for colonization by native riparian plants, and also by weeds. Dams and reservoirs interrupt the longitudinal corridors and we hypothesized that this could restrict downstream weed expansion. To consider this "reservoir impediment" hypothesis we assessed the occurrences and abundances of weeds along a 315-km river valley corridor that commenced with an unimpounded reach of the Snake River and extended through Brownlee, Oxbow, and Hells Canyon reservoirs and dams, and downstream along the Snake River. Sampling along 206 belt transects with 3610 quadrats revealed 16 noxious and four invasive weed species. Ten weeds were upland plants, with Canada thistle (Cirsium arvense) restricted to the upstream reaches, where field morning glory (Convolvulus arvensis) was also more common. In contrast, St. John's wort (Hypericum perforatum) was more abundant below the dams, and medusahead wildrye (Taeniatherum caput-medusae) occurred primarily along the reservoirs. All seven riparian species were abundant in the upstream zones but sparse or absent below the dams. This pattern was observed for the facultative riparian species, poison hemlock (Conium maculatum) and perennial pepperweed (Lepidium latifolium), the obligate riparian, yellow nut sedge (Cyperus esculentus), the invasive perennial, reed canary grass (Phalaris arundinacea), and three invasive riparian trees, Russian olive (Elaeagnus angustifolia), false indigo (Amorpha fruticosa), and tamarisk (Tamarix spp.). The hydrophyte purple loosestrife (Lythrum salicaria) was also restricted to the upstream zone. These longitudinal patterns indicate that the reservoirs have impeded the downstream expansion of riparian weeds, and this may especially result from the repetitive draw-down and refilling of Brownlee Reservoir that imposes a lethal combination of drought and flood stress. The dams and

  1. Conservation of filtering in manufacturing systems with unreliable machines and finished goods buffers

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available This paper addresses the issue of reliable satisfaction of customer demand by unreliable production systems. In the framework of a simple production-storage-customer model, we show that this can be accomplished by using an appropriate level of filtering of production randomness. The filtering is ensured by finished goods buffers (filtering in space and shipping periods (filtering in time. The following question is considered: how are filtering in space and filtering in time interrelated? As an answer, we show that there exists a conservation law: in lean manufacturing systems, the amount of filtering in space multiplied by the amount of filteringin time (both measured in appropriate dimensionless units ispractically constant. Along with providing an insight into the nature of manufacturing systems, this law offers a tool for selecting the smallest, that is, lean, finished goods buffering, which is necessary and sufficient to ensure the desired level ofcustomer demand satisfaction.

  2. Buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions: from protein buffer capacity prediction to bioprocess applications.

    Science.gov (United States)

    Bahrenburg, Sven; Karow, Anne R; Garidel, Patrick

    2015-04-01

    Protein therapeutics, including monoclonal antibodies (mAbs), have significant buffering capacity, particularly at concentrations>50 mg/mL. This report addresses pH-related issues critical to adoption of self-buffered monoclonal antibody formulations. We evaluated solution conditions with protein concentrations ranging from 50 to 250 mg/mL. Samples were both buffer-free and conventionally buffered with citrate. Samples were non-isotonic or adjusted for isotonicity with NaCl or trehalose. Studies included accelerated temperature stability tests, shaking stability studies, and pH changes in infusion media as protein concentrate is added. We present averaged buffering slopes of capacity that can be applied to any mAb and present a general method for calculating buffering capacity of buffer-free, highly concentrated antibody liquid formulations. In temperature stability tests, neither buffer-free nor conventionally buffered solution conditions showed significant pH changes. Conventionally buffered solutions showed significantly higher opalescence than buffer-free ones. In general, buffer-free solution conditions showed less aggregation than conventionally buffered solutions. Shaking stability tests showed no differences between buffer-free and conventionally buffered solutions. "In-use" preparation experiments showed that pH in infusion bag medium can rapidly approximate that of self-buffered protein concentrate as concentrate is added. In summary, the buffer capacity of proteins can be predicted and buffer-free therapeutic antibody preparations provide a viable alternative to conventionally buffered solutions. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Experimental studies of the effects of buffered particle dampers attached to a multi-degree-of-freedom system under dynamic loads

    Science.gov (United States)

    Lu, Zheng; Lu, Xilin; Lu, Wensheng; Masri, Sami F.

    2012-04-01

    This paper presents a systematic experimental investigation of the effects of buffered particle dampers attached to a multi-degree-of-freedom (mdof) system under different dynamic loads (free vibration, random excitation as well as real onsite earthquake excitations), and analytical/computational study of such a system. A series of shaking table tests of a three-storey steel frame with the buffered particle damper system are carried out to evaluate the performance and to verify the analysis method. It is shown that buffered particle dampers have good performance in reducing the response of structures under dynamic loads, especially under random excitation case. It can effectively control the fundamental mode of the mdof primary system; however, the control effect for higher modes is variable. It is also shown that, for a specific container geometry, a certain mass ratio leads to more efficient momentum transfer from the primary system to the particles with a better vibration attenuation effect, and that buffered particle dampers have better control effect than the conventional rigid ones. An analytical solution based on the discrete element method is also presented. Comparison between the experimental and computational results shows that reasonably accurate estimates of the response of a primary system can be obtained. Properly designed buffered particle dampers can effectively reduce the response of lightly damped mdof primary system with a small weight penalty, under different dynamic loads.

  4. Soil organic carbon in riparian forests, rice fields, and pastures in Piedras, Tolima, Colombia.

    Directory of Open Access Journals (Sweden)

    Hernán Jair Andrade-Castañeda

    2016-06-01

    Full Text Available The aim of the study was to estimate the soil organic carbon (SOC storage in the interface between riparian forests and a matrix of rice fields and pastures with organic management. The study took place in Piedras, Tolima, Colombia. Two plots in production (rice and pasture were selected and SOC was estimated in these areas and in the edge and the interior of adjacent riparian forests at a depth of 0 to 20 cm. Bulk density and SOC concentration were quantified between May and July, 2013. Potential change in SOC storage due to land use change among rice fields, pastures, and riparian forests was estimated. The interfaces rice field-riparian forest and pasture-riparian forest stored an average of 65.6 and 61.3 t C/ha, respectively, with no statistical differences (p>0.05. Statistical differences were not detected (p>0.05 between agricultural matrices (rice fields and pastures in any of the variables. The sampling position (matrix and the edge and interior of forests had a significant impact (p<0.05 just in bulk density: 1.7 vs 1.1 vs 1.0 g/cm3 in interior and edge of the riparian forests and the matrix, respectively. SOC was not statistically affected (p>0.05 by the position in the riparian forest-matrix interface. Conversion from riparian forests to rice fields or pastures with organic management is not emitting greenhouse gases, on the contrary, it is increasing SOC in 3.2 t C/ha. 

  5. Explaining linkages (and lack of) between riparian vegetation biodiversity and geomorphic complexity in restored streams of northern Sweden

    Science.gov (United States)

    Polvi, Lina; Maher Hasselquist, Eliza; Nilsson, Christer

    2014-05-01

    plots at three elevations above the low water stage (0, 40, and 80 cm) along five transects; additionally, we determined which species were present within the entire riparian zone (60 m long reach, up to 80 cm elevation). Three metrics of biodiversity were calculated on the plot level (richness, Shannon's diversity index, and evenness); only richness could be examined at the reach scale. There are significant relationships between riparian vegetation biodiversity and the overall complexity gradient at the medium elevation and, based on some metrics, at the low elevation. However, these relationships are not fully explanatory or always linear, explaining up to ~40% of the variability and often being logarithmic. We conclude that reach-scale restoration of increasing complexity in a catchment without significant land-use impacts can have positive effects on biodiversity. However, there are several limiting factors in addition to channel complexity that affect the recovery of riparian zones after restoration: the potential complexity of a reach based on large-scale controls, time since restoration—which is a disturbance in itself, buffer distance to timber harvesting, distance and connectivity to colonist sources, and upland species (e.g., spruce trees) that have managed to colonize when the riparian zone was separated from the channel.

  6. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems

    Science.gov (United States)

    Kraus, Johanna M.; Gibson, Polly P.; Walters, David M.; Mills, Marc A.

    2017-01-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems.However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI,USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r2> 0.78) and had similar mean ΣPCB concentrations when averaged acrossall years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa lesseffective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2016;9999:1–9. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

  7. RIP-ET: A riparian evapotranspiration package for MODFLOW-2005

    Science.gov (United States)

    Maddock, Thomas; Baird, Kathryn J.; Hanson, R.T.; Schmid, Wolfgang; Ajami, Hoori

    2012-01-01

    A new evapotranspiration package for the U.S. Geological Survey's groundwater-flow model, MODFLOW, is documented. The Riparian Evapotranspiration Package (RIP-ET) provides flexibility in simulating riparian and wetland transpiration not provided by the Evapotranspiration (EVT) or Segmented Function Evapotranspiration (ETS1) Packages for MODFLOW 2005. This report describes how the RIP-ET package was conceptualized and provides input instructions, listings and explanations of the source code, and an example. Traditional approaches to modeling evapotranspiration (ET) processes assume a piecewise linear relationship between ET flux and hydraulic head. The RIP-ET replaces this traditional relationship with a segmented, nonlinear dimensionless curve that reflects the eco-physiology of riparian and wetland ecosystems. Evapotranspiration losses from these ecosystems are dependent not only on hydraulic head, but on the plant types present. User-defined plant functional groups (PFGs) are used to elucidate the interaction between plant transpiration and groundwater conditions. Five generalized plant functional groups based on transpiration rates, plant rooting depth, and water tolerance ranges are presented: obligate wetland, shallow-rooted riparian, deep-rooted riparian, transitional riparian and bare ground/open water. Plant functional groups can be further divided into subgroups (PFSGs) based on plant size, density or other characteristics. The RIP-ET allows for partial habitat coverage and mixtures of plant functional subgroups to be present in a single model cell. RIP-ET also distinguishes between plant transpiration and bare-ground evaporation. Habitat areas are designated by polygons; each polygon can contain a mixture of PFSGs and bare ground, and is assigned a surface elevation. This process requires a determination of fractional coverage for each of the plant functional subgroups present in a polygon to account for the mixture of coverage types and resulting

  8. A study on manufacturing and construction method of buffer

    International Nuclear Information System (INIS)

    Chijimatsu, Masakazu; Sugita, Yutaka; Amemiya, Kiyoshi

    1999-09-01

    As an engineered barrier system in the geological disposal of high-level waste, multibarrier system is considered. Multibarrier system consists of the vitrified waste, the overpack and the buffer. Bentonite is one of the potential material as the buffer because of its low water permeability, self-sealing properties, radionuclides adsorption and retardation properties, thermal conductivity, chemical buffering properties, overpack supporting properties, stress buffering properties, etc. In order to evaluate the functions of buffer, a lot of experiments has been conducted. The evaluations of these functions are based on the assumption that the buffer is emplaced or constructed in the disposal tunnel (or disposal pit) properly. Therefore, it is necessary to study on the manufacturing / construction method of buffer. As the manufacturing / construction technology of the buffer, the block installation method and in-situ compaction method, etc, are being investigated. The block installation method is to emplace the buffer blocks manufactured in advance at the ground facility, and construction processes of the block installation method at the underground will be simplified compared with the in-situ compaction method. On the other hand, the in-situ compaction method is to introduce the buffer material with specified water content into the disposal tunnel and to make the buffer with high density at the site using a compaction machine. In regard to the in-situ compaction method, it is necessary to investigate the optimum finished thickness of one layer because it is impossible to construct the buffer at one time. This report describes the results of compaction property test and the summary of the past investigation results in connection with the manufacturing / construction method. Then this report shows the construction method that will be feasible in the actual disposal site. (J.P.N.)

  9. Managing Multiuser Database Buffers Using Data Mining Techniques

    NARCIS (Netherlands)

    Feng, L.; Lu, H.J.

    2004-01-01

    In this paper, we propose a data-mining-based approach to public buffer management for a multiuser database system, where database buffers are organized into two areas – public and private. While the private buffer areas contain pages to be updated by particular users, the public

  10. Water quality modeling based on landscape analysis: Importance of riparian hydrology

    Science.gov (United States)

    Thomas Grabs

    2010-01-01

    Several studies in high-latitude catchments have demonstrated the importance of near-stream riparian zones as hydrogeochemical hotspots with a substantial influence on stream chemistry. An adequate representation of the spatial variability of riparian-zone processes and characteristics is the key for modeling spatiotemporal variations of stream-water quality. This...

  11. Buffered Communication Analysis in Distributed Multiparty Sessions

    Science.gov (United States)

    Deniélou, Pierre-Malo; Yoshida, Nobuko

    Many communication-centred systems today rely on asynchronous messaging among distributed peers to make efficient use of parallel execution and resource access. With such asynchrony, the communication buffers can happen to grow inconsiderately over time. This paper proposes a static verification methodology based on multiparty session types which can efficiently compute the upper bounds on buffer sizes. Our analysis relies on a uniform causality audit of the entire collaboration pattern - an examination that is not always possible from each end-point type. We extend this method to design algorithms that allocate communication channels in order to optimise the memory requirements of session executions. From these analyses, we propose two refinements methods which respect buffer bounds: a global protocol refinement that automatically inserts confirmation messages to guarantee stipulated buffer sizes and a local protocol refinement to optimise asynchronous messaging without buffer overflow. Finally our work is applied to overcome a buffer overflow problem of the multi-buffering algorithm.

  12. Efficient Computation of Buffer Capacities for Cyclo-Static Dataflow Graphs

    NARCIS (Netherlands)

    Wiggers, M.H.; Bekooij, Marco Jan Gerrit; Bekooij, Marco J.G.; Smit, Gerardus Johannes Maria

    A key step in the design of cyclo-static real-time systems is the determination of buffer capacities. In our multi-processor system, we apply back-pressure, which means that tasks wait for space in output buffers. Consequently buffer capacities affect the throughput. This requires the derivation of

  13. Efficient Computation of Buffer Capacities for Cyclo-Static Dataflow Graphs

    NARCIS (Netherlands)

    Wiggers, M.H.; Bekooij, Marco Jan Gerrit; Smit, Gerardus Johannes Maria

    2006-01-01

    A key step in the design of cyclo-static real-time systems is the determination of buffer capacities. In our multi-processor system, we apply back-pressure, which means that tasks wait for space in output buffers. Consequently buffer capacities affect the throughput. This requires the derivation of

  14. Influence of Gully Erosion Control on Amphibian and Reptile Communities within Riparian Zones of Channelized Streams

    Science.gov (United States)

    Riparian zones of streams in northwestern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Riparian gully formation has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used conservation practice for...

  15. Evaluating hillslope and riparian contributions to dissolved nitrogen (N) export from a boreal forest catchment

    Science.gov (United States)

    Blackburn, M.; Ledesma, José L. J.; Näsholm, Torgny; Laudon, Hjalmar; Sponseller, Ryan A.

    2017-02-01

    Catchment science has long held that the chemistry of small streams reflects the landscapes they drain. However, understanding the contribution of different landscape units to stream chemistry remains a challenge which frequently limits our understanding of export dynamics. For limiting nutrients such as nitrogen (N), an implicit assumption is that the most spatially extensive landscape units (e.g., uplands) act as the primary sources to surface waters, while near-stream zones function more often as sinks. These assumptions, based largely on studies in high-gradient systems or in regions with elevated inputs of anthropogenic N, may not apply to low-gradient, nutrient-poor, and peat-rich catchments characteristic of many northern ecosystems. We quantified patterns of N mobilization along a hillslope transect in a northern boreal catchment to assess the extent to which organic matter-rich riparian soils regulate the flux of N to streams. Contrary to the prevailing view of riparian functioning, we found that near-stream, organic soils supported concentrations and fluxes of ammonium (NH4+) and dissolved organic nitrogen that were much higher than the contributing upslope forest soils. These results suggest that stream N chemistry is connected to N mobilization and mineralization within the riparian zone rather than the wider landscape. Results further suggest that water table fluctuation in near-surface riparian soils may promote elevated rates of net N mineralization in these landscapes.

  16. Flow and transport in Riparian Zones

    DEFF Research Database (Denmark)

    Jensen, Jannick Kolbjørn

    scenarios with changing conditions for flow (steady state with no flooding or transient with flooding), hydrogeology, denitrification rate, and extent of flooding it is demonstrated how flow paths, residence times, and nitrate removal are affected. With this previous conceptual models on the hydrology......The PhD study presents research results from two re-established Danish riparian zones, Brynemade and Skallebanke, located along Odense River on the island Funen, Denmark. The overall objectives of the PhD study have been to improve the understanding of flow and transport in riparian zones....... The methodology focuses on; construction of field sites along Odense River, understanding flow and transport, and performing numerical/analytical model assessments of flow and transport. An initial 2D simulation study was performed with a conceptual setup based on the Brynemade site. Through a series of 2D model...

  17. Beyond cool: adapting upland streams for climate change using riparian woodlands.

    Science.gov (United States)

    Thomas, Stephen M; Griffiths, Siân W; Ormerod, Steve J

    2016-01-01

    Managed adaptation could reduce the risks of climate change to the world's ecosystems, but there have been surprisingly few practical evaluations of the options available. For example, riparian woodland is advocated widely as shade to reduce warming in temperate streams, but few studies have considered collateral effects on species composition or ecosystem functions. Here, we use cross-sectional analyses at two scales (region and within streams) to investigate whether four types of riparian management, including those proposed to reduce potential climate change impacts, might also affect the composition, functional character, dynamics and energetic resourcing of macroinvertebrates in upland Welsh streams (UK). Riparian land use across the region had only small effects on invertebrate taxonomic composition, while stable isotope data showed how energetic resources assimilated by macroinvertebrates in all functional guilds were split roughly 50:50 between terrestrial and aquatic origins irrespective of riparian management. Nevertheless, streams draining the most extensive deciduous woodland had the greatest stocks of coarse particulate matter (CPOM) and greater numbers of 'shredding' detritivores. Stream-scale investigations showed that macroinvertebrate biomass in deciduous woodland streams was around twice that in moorland streams, and lowest of all in streams draining non-native conifers. The unexpected absence of contrasting terrestrial signals in the isotopic data implies that factors other than local land use affect the relative incorporation of allochthonous subsidies into riverine food webs. Nevertheless, our results reveal how planting deciduous riparian trees along temperate headwaters as an adaptation to climate change can modify macroinvertebrate function, increase biomass and potentially enhance resilience by increasing basal resources where cover is extensive (>60 m riparian width). We advocate greater urgency in efforts to understand the ecosystem

  18. Buffer management in wireless full-duplex systems

    KAUST Repository

    Bouacida, Nader; Showail, Ahmad; Shihada, Basem

    2015-01-01

    , we address the problem of buffer management in full-duplex networks by using Wireless Queue Management (WQM), which is an active queue management technique for wireless networks. Our solution is based on Relay Full-Duplex MAC (RFD

  19. Do invasive riparian Tamarix alter hydrology of riparian areas of arid and semi-arid regions under climate change scenarios?

    Science.gov (United States)

    Bhattarai, M. P.; Acharya, K.; Chen, L.

    2012-12-01

    Competitiveness of riparian invasive species, Tamarix, in arid and semi-arid riparian areas of the southwestern United States under climate change scenario (SRES A2) was investigated. Tamarix has been replacing native vegetation along the riparian corridors of these areas for the past several decades and is thought to alter water balance. Changes in depth to groundwater, soil moisture distribution and flood frequency are critical in survival and growth of a facultative phreatophyte such as Tamarix. In this study, a fully coupled 2d surface flow and 3d subsurface flow hydrologic model, HydroGeoSphere, was used to simulate surface-subsurface hydrology of the lower Virgin River basin (4500 sq. km), located in Nevada, Utah and Arizona. The hydrologic model results, depth to groundwater and soil saturation, were then applied to the species distribution model, Maxent, along with other bioclimatic parameters to asses future Tamarix distribution probability. Simulations were made for the climate scenarios of the end of 21st centry conditions. Depth to groundwater is found to be the most important predictor variable to the Maxent model. Future Tamarix distribution range is not uniform across the basin. It is likely to decrease at lower elevations and increase in some higher elevation areas.

  20. Tamarix and Diorhabda leaf beetle interactions: implications for Tamarix water use and riparian habitat

    Science.gov (United States)

    Nagler, Pamela; Glenn, Edward P.

    2013-01-01

    Tamarix leaf beetles (Diorhabda carinulata) have been widely released on western United States rivers to control introduced shrubs in the genus Tamarix, with the goals of saving water through removal of an assumed high water-use plant, and of improving habitat value by removing a competitor of native riparian trees. We review recent studies addressing three questions: (1) to what extent are Tamarix weakened or killed by recurrent cycles of defoliation; (2) can significant water salvage be expected from defoliation; and (3) what are the effects of defoliation on riparian ecology, particularly on avian habit? Defoliation has been patchy at many sites, and shrubs at some sites recover each year even after multiple years of defoliation. Tamarix evapotranspiration (ET) is much lower than originally assumed in estimates of potential water savings, and are the same or lower than possible replacement plants. There is concern that the endangered southwestern willow flycatcher (Empidonax trailli extimus) will be negatively affected by defoliation because the birds build nests early in the season when Tamarix is still green, but are still on their nests during the period of summer defoliation. Affected river systems will require continued monitoring and development of adaptive management practices to maintain or enhance riparian habitat values. Multiplatform remote sensing methods are playing an essential role in monitoring defoliation and rates of ET on affected river systems.

  1. Systematic generation of buffer systems for pH gradient ion exchange chromatography and their application.

    Science.gov (United States)

    Kröner, Frieder; Hubbuch, Jürgen

    2013-04-12

    pH gradient protein separations are widely used techniques in the field of protein analytics, of which isoelectric focusing is the most well known application. The chromatographic variant, based on the formation of pH gradients in ion exchange columns is only rarely applied due to the difficulties to form controllable, linear pH gradients over a broad pH range. This work describes a method for the systematic generation of buffer compositions with linear titration curves, resulting in well controllable pH gradients. To generate buffer compositions with linear titration curves an in silico method was successfully developed. With this tool, buffer compositions for pH gradient ion exchange chromatography with pH ranges spanning up to 7.5 pH units were established and successfully validated. Subsequently, the buffer systems were used to characterize the elution behavior of 22 different model proteins in cation and anion exchange pH gradient chromatography. The results of both chromatographic modes as well as isoelectric focusing were compared to describe differences in between the methods. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Analysis of two production inventory systems with buffer, retrials and different production rates

    Science.gov (United States)

    Jose, K. P.; Nair, Salini S.

    2017-09-01

    This paper considers the comparison of two ( {s,S} ) production inventory systems with retrials of unsatisfied customers. The time for producing and adding each item to the inventory is exponentially distributed with rate β. However, a production rate α β higher than β is used at the beginning of the production. The higher production rate will reduce customers' loss when inventory level approaches zero. The demand from customers is according to a Poisson process. Service times are exponentially distributed. Upon arrival, the customers enter into a buffer of finite capacity. An arriving customer, who finds the buffer full, moves to an orbit. They can retry from there and inter-retrial times are exponentially distributed. The two models differ in the capacity of the buffer. The aim is to find the minimum value of total cost by varying different parameters and compare the efficiency of the models. The optimum value of α corresponding to minimum total cost is an important evaluation. Matrix analytic method is used to find an algorithmic solution to the problem. We also provide several numerical or graphical illustrations.

  3. Forestry Best Management Practices Relationships with Aquatic and Riparian Fauna: A Review

    Directory of Open Access Journals (Sweden)

    Brooke M. Warrington

    2017-09-01

    Full Text Available Forestry best management practices (BMPs were developed to minimize water pollution from forestry operations by primarily addressing sediment and sediment transport, which is the leading source of pollution from silviculture. Implementation of water quality BMPs may also benefit riparian and aquatic wildlife, although wildlife benefits were not driving forces for BMP development. Therefore, we reviewed literature regarding potential contributions of sediment-reducing BMPs to conservation of riparian and aquatic wildlife, while realizing that BMPs also minimize thermal, nutrient, and chemical pollution. We reached five important conclusions: (1 a significant body of research confirms that forestry BMPs contribute to the protection of water quality and riparian forest structure; (2 data-specific relationships between forestry BMPs and reviewed species are limited; (3 forestry BMPs for forest road construction and maintenance, skid trails, stream crossings, and streamside management zones (SMZs are important particularly for protection of water quality and aquatic species; (4 stream crossings should be carefully selected and installed to minimize sediment inputs and stream channel alterations; and (5 SMZs promote retention of older-age riparian habitat with benefits extending from water bodies to surrounding uplands. Overall, BMPs developed for protection of water quality should benefit a variety of riparian and aquatic species that are sensitive to changes in water quality or forest structure.

  4. Forestry best management practices relationships with aquatic and riparian fauna: A review

    Science.gov (United States)

    Warrington, Brooke M.; Aust, W. Michael; Barrett, Scott M.; Ford, W. Mark; Dolloff, C. Andrew; Schilling, Erik B.; Wigley, T. Bently; Bolding, M. Chad

    2017-01-01

    Forestry best management practices (BMPs) were developed to minimize water pollution from forestry operations by primarily addressing sediment and sediment transport, which is the leading source of pollution from silviculture. Implementation of water quality BMPs may also benefit riparian and aquatic wildlife, although wildlife benefits were not driving forces for BMP development. Therefore, we reviewed literature regarding potential contributions of sediment-reducing BMPs to conservation of riparian and aquatic wildlife, while realizing that BMPs also minimize thermal, nutrient, and chemical pollution. We reached five important conclusions: (1) a significant body of research confirms that forestry BMPs contribute to the protection of water quality and riparian forest structure; (2) data-specific relationships between forestry BMPs and reviewed species are limited; (3) forestry BMPs for forest road construction and maintenance, skid trails, stream crossings, and streamside management zones (SMZs) are important particularly for protection of water quality and aquatic species; (4) stream crossings should be carefully selected and installed to minimize sediment inputs and stream channel alterations; and (5) SMZs promote retention of older-age riparian habitat with benefits extending from water bodies to surrounding uplands. Overall, BMPs developed for protection of water quality should benefit a variety of riparian and aquatic species that are sensitive to changes in water quality or forest structure.

  5. Stream characteristics and their implications for the protection of riparian fens and meadows

    DEFF Research Database (Denmark)

    Baattrup-Pedersen, A.; Larsen, S.E.; Andersen, Peter Mejlhede

    2011-01-01

    the influence of stream size, morphology and chemical water characteristics for the distribution of water-dependent terrestrial habitat types, i.e. alkaline fens, periodically inundated meadows and meadows in riparian areas in Denmark using an extensive data set covering a total of 254 stream reaches. A species......1. Running waters, including associated riparian areas, are embraced by international legal frameworks outlining targets for the preservation, protection and improvement of the quality of the environment. Interactions between stream and river processes and riparian habitats have not received much...... attention in the management of stream ecosystems, and integrated measures that consider both the ecological status of streams and rivers (sensu EU Water Framework Directive, WFD) and the conservation status of riparian habitats and species (sensu EU Habitats Directive, HD) are rare. 2. Here, we analysed...

  6. Taxonomic and compositional differences of ground-dwelling arthropods in riparian habitats in Glen Canyon, Arizona, USA

    Science.gov (United States)

    Ralston, Barbara; Cobb, Neil S.; Brantley, Sandra L.; Higgins, Jacob; Yackulic, Charles B.

    2017-01-01

    The disturbance history, plant species composition, productivity, and structural complexity of a site can exert bottom-up controls on arthropod diversity, abundance, and trophic structure. Regulation alters the hydrology and disturbance regimes of rivers and affects riparian habitats by changing plant quality parameters. Fifty years of regulation along the Colorado River downstream of Glen Canyon Dam has created a no-analog, postdam “lower” riparian zone close to the water's edge that includes tamarisk (Tamarix sp.), a nonnative riparian shrub. At the same time, the predam “upper” facultative riparian zone has persisted several meters above the current flood stage. In summer 2009, we used pitfall traps within these 2 riparian zones that differ in plant composition, productivity, and disturbance frequency to test for differences in arthropod community (Hymenoptera, Arachnida, and Coleoptera) structure. Arthropod community structure differed substantially between the 2 zones. Arthropod abundance and species richness was highest in the predam upper riparian zone, even though there was a greater amount of standing plant biomass in the postdam lower riparian zone. Omnivore abundance was proportionately greater in the upper riparian zone and was associated with lower estimated productivity values. Predators and detritivores were proportionately greater in the postdam lower riparian zone. In this case, river regulation may create habitats that support species of spiders and carabid beetles, but few other species that are exclusive to this zone. The combined richness found in both zones suggests a small increase in total richness and functional diversity for the Glen Canyon reach of the Colorado River.

  7. SOIL NITROUS OXIDE, NITRIC OXIDE, AND AMMONIA EMISSIONS FROM A RECOVERING RIPARIAN ECOSYSTEM IN SOUTHERN APPALACHIA

    Science.gov (United States)

    The paper presents two years of seasonal nitric oxide, ammonia, and nitrous oxide trace gas fluxes measured in a recovering riparian zone with cattle excluded and in an adjacent riparian zone grazed by cattle. In the recovering riparian zone, average nitric oxide, ammonia, and ni...

  8. Random River Fluctuations Shape the Root Profile of Riparian Plants

    Science.gov (United States)

    Perona, P.; Tron, S.; Gorla, L.; Schwarz, M.; Laio, F.; Ridolfi, L.

    2015-12-01

    Plant roots are recognized to play a key role in the riparian ecosystems: they contribute to the plant as well as to the streambank and bedforms stability, help to enhance the water quality of the river, and sustain the belowground biodiversity. The complexity of the root-system architecture recalls their remarkable ability to respond to environmental conditions, notably including soil heterogeneity, resource availability, and climate. In fluvial environments where nutrient availability is not a limiting factor for plant to grow, the root growth of phreatophytic plants is strongly influenced by water and oxygen availability in the soil. In this work, we demonstrate that the randomness of water table fluctuations, determined by streamflow stochastic variability, is likely to be the main driver for the root development strategy of riparian plants. A collection of root measurements from field and outdoor controlled experiments is used to demonstrate that the vertical root density distribution can be described by a simple analytical expression, whose parameters are linked to properties of soil, plant and water table fluctuations. This physically-based expression is able to predict riparian plant roots adaptability to different hydrological and pedologic scenarios in riverine environments. Hence, this model has great potential towards the comprehension of the effects of future climate and environmental changing conditions on plant adaptation and river ecomorphodynamic processes. Finally, we present an open access graphical user interface that we developed in order to estimate the vertical root distribution in fluvial environments and to make the model easily available to a wider scientific and professional audience.

  9. Assessment and preliminary design of an energy buffer for regenerative braking in electric vehicles

    Science.gov (United States)

    Buchholz, R.; Mathur, A. K.

    1979-01-01

    Energy buffer systems, capable of storing the vehicle energy during braking and reusing this stored energy during acceleration, were examined. Some of these buffer systems when incorporated in an electric vehicle would result in an improvement in the performance and range under stop and go driving conditions. Buffer systems considered included flywheels, hydropneumatic, pneumatic, spring, and regenerative braking. Buffer ranking and rating criteria were established. Buffer systems were rated based on predicted range improvements, consumer acceptance, driveability, safety, reliability and durability, and initial and life cycle costs. A hydropneumatic buffer system was selected.

  10. Redox Buffer Strength

    Science.gov (United States)

    de Levie, Robert

    1999-04-01

    The proper functioning of enzymes in bodily fluids requires that the pH be maintained within rather narrow limits. The first line of defense against large pH fluctuations in such fluids is the passive control provided by the presence of pH buffers. The ability of pH buffers to stabilize the pH is indicated by the buffer value b introduced in 1922 by van Slyke. It is equally important for many enzymes that the redox potential is kept within a narrow range. In that case, stability of the potential is most readily achieved with a redox buffer. In this communication we define the redox buffer strength by analogy with acid-base buffer strength.

  11. Riparian spiders as sentinels of polychlorinated biphenyl contamination across heterogeneous aquatic ecosystems.

    Science.gov (United States)

    Kraus, Johanna M; Gibson, Polly P; Walters, David M; Mills, Marc A

    2017-05-01

    Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. The present study tests the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. The spatial pattern of ΣPCB concentrations in 2 common families of riparian spiders sampled in 2011 to 2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique (MI, USA) that includes harbor, river, backwater, and lake habitats. Sediment ΣPCB concentrations normalized for total organic carbon explained 41% of the variation in lipid-normalized spider ΣPCB concentrations across 11 sites. Furthermore, 2 common riparian spider taxa (Araneidae and Tetragnathidae) were highly correlated (r 2  > 0.78) and had similar mean ΣPCB concentrations when averaged across all years. The results indicate that riparian spiders may be useful sentinels of relative PCB availability to aquatic and riparian food webs in heterogeneous aquatic ecosystems like rivermouths where habitat and contaminant variability may make the use of aquatic taxa less effective. Furthermore, the present approach appears robust to heterogeneity in shoreline development and riparian vegetation that support different families of large web-building spiders. Environ Toxicol Chem 2017;36:1278-1286. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals, Inc. on behalf of SETAC. This article is a US government work and, as such, is in

  12. 78 FR 16705 - Llano Seco Riparian Sanctuary Unit Restoration and Pumping Plant/Fish Screen Facility Protection...

    Science.gov (United States)

    2013-03-18

    ...-FF08RSRC00] Llano Seco Riparian Sanctuary Unit Restoration and Pumping Plant/ Fish Screen Facility Protection... removal and management of invasive plant species would occur at the Riparian Sanctuary. No active... impact statement and environmental impact report (EIS/EIR) for the Llano Seco Riparian Sanctuary Unit...

  13. 77 FR 26569 - Llano Seco Riparian Sanctuary Unit Restoration and Pumping Plant/Fish Screen Facility Protection...

    Science.gov (United States)

    2012-05-04

    ...-FF08RSRC00] Llano Seco Riparian Sanctuary Unit Restoration and Pumping Plant/ Fish Screen Facility Protection... would occur at the Riparian Sanctuary. No active restoration of native plants would occur. Maintenance... statement and environmental impact report (EIS/EIR) for the Llano Seco Riparian Sanctuary Unit Restoration...

  14. Flora of the San Pedro Riparian National Conservation Area, Cochise County, Arizona

    Science.gov (United States)

    Elizabeth Makings

    2005-01-01

    The flora of the San Pedro Riparian National Conservation Area (SPRNCA) consists of 618 taxa from 92 families, including a new species of Eriogonum and four new State records. The vegetation communities include Chihuahuan Desertscrub, cottonwood-willow riparian corridors, mesquite terraces, sacaton grasslands, rocky outcrops, and cienegas. Species...

  15. Geography of spring landbird migration through riparian habitats in southwestern North America

    Science.gov (United States)

    Susan K. Skagen; Jeffrey F. Kelly; Charles van Riper III; Richard L. Hutto; Deborah M. Finch; David J. Krueper; Cynthia P. Melcher

    2005-01-01

    Migration stopover resources, particularly riparian habitats, are critically important to landbirds migrating across the arid southwestern region of North America. To explore the effects of species biogeography and habitat affinity on spring migration patterns, we synthesized existing bird abundance and capture data collected in riparian habitats of the borderlands...

  16. Water sources accessed by arid zone riparian trees in highly saline environments, Australia.

    Science.gov (United States)

    Costelloe, Justin F; Payne, Emily; Woodrow, Ian E; Irvine, Elizabeth C; Western, Andrew W; Leaney, Fred W

    2008-05-01

    The flow regimes of arid zone rivers are often highly variable, and shallow groundwater in the alluvial aquifers can be very saline, thus constraining the availability and quality of the major water sources available to riparian trees-soil water, shallow groundwater and stream water. We have identified water sources and strategies used by riparian trees in more highly saline and arid conditions than previously studied for riparian trees of arid zone rivers. Our research focused on the riparian species Eucalyptus coolabah, one of the major riparian trees of ephemeral arid zone rivers in Australia. The water sources available to this riparian tree were examined using delta(18)O isotope data from xylem, soil water, groundwater and surface water. Additionally, soil chloride and matric potential data were used to infer zones of water availability for root uptake. Despite the saline conditions, the trees used a mixture of soil water and groundwater sources, but they did not use surface water directly. The study identified three strategies used to cope with typically high groundwater and soil water salinities. Firstly, the trees preferentially grow in zones of most frequent flushing by infiltrating streamflow, such as the bank-tops of channels. Secondly, the trees limit water use by having low transpiration rates. Thirdly, the trees are able to extract water at very low osmotic potentials, with water uptake continuing at chloride concentrations of at least 20,000-30,000 mg L(-1).

  17. Review of Invasive Riparian Trees that Impact USACE Ecosystem Restoration Projects

    Science.gov (United States)

    2016-08-01

    often release seeds in periods of stress , including periods when exposed to herbicides or mechanical disturbances. Such characteristics make this...Approved for public release ; distribution is unlimited. ERDC TN-EMRRP-SI-36 August 2016 Review of Invasive Riparian Trees that Impact USACE...various spatial control methods for woody invasive plant removal in densely vegetated riparian habitats. The USACE ecosystem restoration mission has

  18. The Phytophthora species assemblage and diversity in riparian alder ecosystems of western Oregon, USA.

    Science.gov (United States)

    Sims, Laura Lee; Sutton, Wendy; Reeser, Paul; Hansen, Everett M

    2015-01-01

    Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were recovered from all substrates (streams, soil, alder roots): P. gonapodyides, the informally described "P. taxon Pgchlamydo", and P. siskiyouensis. P. alni ssp. uniformis along with five other species not previously recovered in Oregon forests are included in the assemblage: P.citricola s.l., P. gregata, P. gallica, P. nicotianae and P. parsiana. Phytophthora species diversity was greatest in downstream riparian locations. There was no significant difference in species diversity comparing soil and unwashed roots (the rhizosphere) to stream water. There was a difference between the predominating species from the rhizosphere compared to stream water. The most numerous species was the informally described "P. taxon Oaksoil", which was mainly recovered from, and most predominant in, stream water. The most common species from riparian forest soils and alder root systems was P. gonapodyides. © 2015 by The Mycological Society of America.

  19. Evapotranspiration Calculation on the Basis of the Riparian Zone Water Balance

    Directory of Open Access Journals (Sweden)

    SZILÁGYI, József

    2008-01-01

    Full Text Available Riparian forests have a strong influence on groundwater levels and groundwater sustainedstream baseflow. An empirical and a hydraulic version of a new method were developed to calculateevapotranspiration values from riparian zone groundwater levels. The new technique was tested on thehydrometeorological data set of the Hidegvíz Valley (located in Sopron Hills at the eastern foothills ofthe Alps experimental catchment. Evapotranspiration values of this new method were compared tothe Penman-Monteith evapotranspiration values on a half hourly scale and to the White methodevapotranspiration values on a daily scale. Sensitivity analysis showed that the more reliable hydraulicversion of our ET estimation technique is most sensitive (i.e., linearly to the values of the saturatedhydraulic conductivity and specific yield taken from the riparian zone.

  20. The quantitation of buffering action II. Applications of the formal & general approach

    Science.gov (United States)

    Schmitt, Bernhard M

    2005-01-01

    Background The paradigm of "buffering" originated in acid-base physiology, but was subsequently extended to other fields and is now used for a wide and diverse set of phenomena. In the preceding article, we have presented a formal and general approach to the quantitation of buffering action. Here, we use that buffering concept for a systematic treatment of selected classical and other buffering phenomena. Results H+ buffering by weak acids and "self-buffering" in pure water represent "conservative buffered systems" whose analysis reveals buffering properties that contrast in important aspects from classical textbook descriptions. The buffering of organ perfusion in the face of variable perfusion pressure (also termed "autoregulation") can be treated in terms of "non-conservative buffered systems", the general form of the concept. For the analysis of cytoplasmic Ca++ concentration transients (also termed "muffling"), we develop a related unit that is able to faithfully reflect the time-dependent quantitative aspect of buffering during the pre-steady state period. Steady-state buffering is shown to represent the limiting case of time-dependent muffling, namely for infinitely long time intervals and infinitely small perturbations. Finally, our buffering concept provides a stringent definition of "buffering" on the level of systems and control theory, resulting in four absolute ratio scales for control performance that are suited to measure disturbance rejection and setpoint tracking, and both their static and dynamic aspects. Conclusion Our concept of buffering provides a powerful mathematical tool for the quantitation of buffering action in all its appearances. PMID:15771784

  1. Implementing the countercyclical capital buffer in South Africa: Practical considerations

    Directory of Open Access Journals (Sweden)

    Pravin Burra

    2015-03-01

    Full Text Available The Basel II regulatory framework significantly increased the resilience of the banking system, but proved ineffective in preventing the 2008/9 financial crisis. The subsequent introduction of Basel III aimed, inter alia, to supplement bank capital using buffers. The countercyclical buffer boosts existing minimum capital requirements when systemic risk surges are detected. Bolstering capital in favourable economic conditions cushions losses in unfavourable conditions, thereby addressing capital requirement procyclicality. This paper contains an overview of the countercyclical capital buffer and a critical discussion of its implementation as proposed in Basel III. Consequences of the buffer's introduction for South African banks are explored, and in particular, potential systemic risk indicator variables are identified that may be used by the South African Reserve Bank (SARB as early warning indicators of imminent systemic financial distress. These indicators may be of value to the SARB, which could use them in taking decisions on the build-up and release of the countercyclical buffer for South African banks.

  2. Climate change and wildfire effects in aridland riparian ecosystems: An examination of current and future conditions

    Science.gov (United States)

    D. Max Smith; Deborah M. Finch

    2017-01-01

    Aridland riparian ecosystems are limited, the climate is changing, and further hydrological change is likely in the American Southwest. To protect riparian ecosystems and organisms, we need to understand how they are affected by disturbance processes and stressors such as fire, drought, and non-native plant invasions. Riparian vegetation is critically important as...

  3. Presence of riparian vegetation increases biotic condition of fish assemblages in two Brazilian reservoirs

    Directory of Open Access Journals (Sweden)

    Fabio Cop Ferreira

    2015-09-01

    Full Text Available Abstract The riparian vegetation in lakes and reservoirs is source of course wood structures such as trunks and branches and is used as sheltering, spawning and foraging habitats for fishes. The reduction of these submerged structures can thus, affect the composition and structure of fish assemblages in reservoirs. Aim To evaluate the influence of riparian vegetation on the biotic condition of fish assemblage by adapting the Reservoir Fish Assemblage Index (RFAI to two reservoirs in the Upper Paranapanema river basin, São Paulo State, Brazil. Methods The RFAI was adapted from metrics related to the functional characteristics and composition of fish assemblages through a protocol of metric selection and validation, and to its response to the presence of riparian vegetation. Results The final RFAI was composed by nine metrics, been lower in sites without riparian vegetation as consequence of the predominance of larger individuals and the percent of piscivorous and detritivorous fishes. Conclusions These results suggest that increasing shore habitat complexity in reservoirs by maintaining riparian vegetation increases fish biotic integrity.

  4. Cicada emergence in southwestern riparian forest: Influences of wildfire and vegetation composition

    Science.gov (United States)

    D. Max Smith; Jeffrey Kelly; Deborah M. Finch

    2006-01-01

    Annually emerging cicadas are a numerically and ecologically dominant species in Southwestern riparian forests. Humans have altered disturbance regimes that structure these forests such that floods are less common and wildfires occur more frequently than was historically the case. Impacts of these changes on primary consumers such as riparian cicadas are unknown....

  5. The brown-headed cowbird and its riparian-dependent hosts in New Mexico

    Science.gov (United States)

    Sara H. Schweitzer; Deborah M. Finch; David M Leslie

    1998-01-01

    Numbers of brown-headed cowbirds ( Molothrus ater) are increasing in some regions of North America, while certain populations of long-distance, neotropical migratory songbirds (NTMs) are declining. In the Southwestern United States, several species of NTMs nest only in riparian habitats. The significant decline of two species of NTMs dependent upon riparian habitat,...

  6. Buffers Plus

    Science.gov (United States)

    Ramette, Richard W.

    1998-11-01

    In 1989 JCE Software published The Acid-Base Package: A Collection of Useful Programs for Proton Transfer Systems (Ramette, R. W. J. Chem. Educ. Software 1989, 2B No. 2). This DOS program has been fully upgraded by the same author to the world of Windows 95. Buffers Plus takes advantage of a modern user interface and offers many new options not possible in the original version.

  7. Effects of drought on birds and riparian vegetation in the Colorado River Delta, Mexico

    Science.gov (United States)

    Hinojosa-Huerta, Osvel; Nagler, Pamela L.; Carrillo-Guererro, Yamilett K.; Glenn, Edward P.

    2013-01-01

    The riparian corridor in the delta of the Colorado River in Mexico supports internationally important bird habitat. The vegetation is maintained by surface flows from the U.S. and Mexico and by a high, non-saline aquifer into which the dominant phreatophytic shrubs and trees are rooted. We studied the effects of a regional drought on riparian vegetation and avian abundance and diversity from 2002 to 2007, during which time surface flows were markedly reduced compared to the period from 1995 to 2002. Reduced surface flows led to a reduction in native tree cover but an increase in shrub cover, mostly due to an increase in Tamarix spp., an introduced halophytic shrub, and a reduction in Populus fremontii and Salix gooddingii trees. However, overall vegetation cover was unchanged at about 70%. Overall bird density and diversity were also unchanged, but riparian-obligate species tended to decrease in abundance, and generalist species increased. Although reduction in surface flows reduced habitat value and negatively impacted riparian-obligate bird species, portions of the riparian zone exhibited resilience. Surface flows are required to reduce soil salt levels and germinate new cohorts of native trees, but the main source of water supporting this ecosystem is the aquifer, derived from underflows from irrigated fields in the U.S. and Mexico. The long-term prospects for delta riparian habitats are uncertain due to expected reduced flows of river water from climate change, and land use practices that will reduce underflows to the riparian aquifer and increase salinity levels. Active restoration programs would be needed if these habitats are to be preserved for the future.

  8. Developing rapid methods for analyzing upland riparian functions and values.

    Science.gov (United States)

    Hruby, Thomas

    2009-06-01

    Regulators protecting riparian areas need to understand the integrity, health, beneficial uses, functions, and values of this resource. Up to now most methods providing information about riparian areas are based on analyzing condition or integrity. These methods, however, provide little information about functions and values. Different methods are needed that specifically address this aspect of riparian areas. In addition to information on functions and values, regulators have very specific needs that include: an analysis at the site scale, low cost, usability, and inclusion of policy interpretations. To meet these needs a rapid method has been developed that uses a multi-criteria decision matrix to categorize riparian areas in Washington State, USA. Indicators are used to identify the potential of the site to provide a function, the potential of the landscape to support the function, and the value the function provides to society. To meet legal needs fixed boundaries for assessment units are established based on geomorphology, the distance from "Ordinary High Water Mark" and different categories of land uses. Assessment units are first classified based on ecoregions, geomorphic characteristics, and land uses. This simplifies the data that need to be collected at a site, but it requires developing and calibrating a separate model for each "class." The approach to developing methods is adaptable to other locations as its basic structure is not dependent on local conditions.

  9. Simulating and evaluating best management practices for integrated landscape management scenarios in biofuel feedstock production: Evaluating Best Management Practices for Biofuel Feedstock Production

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Miae [Argonne National Laboratory, Lemont IL 60439 USA; Wu, May [Argonne National Laboratory, Lemont IL 60439 USA

    2015-09-08

    Sound crop and land management strategies can maintain land productivity and improve the environmental sustainability of agricultural crop and feedstock production. This study evaluates the improvement of water sustainability through an integrated landscaping management strategy, where landscaping design, land management operations, crop systems, and agricultural best management practices (BMPs) play equal roles. The strategy was applied to the watershed of the South Fork Iowa River in Iowa, with a focus on implementing riparian buffers and converting low productivity land to provide cellulosic biomass while benefiting soil and water quality. The Soil and Water Assessment Tool (SWAT) was employed to simulate the impact of integrated landscape design on nutrients, suspended sediments, and flow on the watershed and subbasin scales. First, the study evaluated the representation of buffer strip as a vegetative barrier and as a riparian buffer using trapping efficiency and area ratio methods in SWAT. For the riparian buffer, the area ratio method tends to be more conservative, especially in nitrate loadings, while the trapping efficiency method generates more optimistic results. The differences between the two methods increase with buffer width. The two methods may not be comparable for the field-scale vegetative barrier simulation because of limitations in model spatial resolution. Landscape scenarios were developed to quantify water quality under (1) current land use, (2) partial land conversion to switchgrass, and (3) riparian buffer implementation. Results show that when low productivity land (15.2% of total watershed land area) is converted to grow switchgrass, suspended sediment, total nitrogen, total phosphorus, and nitrate loadings are reduced by 69.3%, 55.5%, 46.1%, and 13.4%, respectively, in the watershed surface streams. The reduction was less extensive when riparian buffer strips (30 m or 50 m) were applied to the stream network at 1.4% of total land area

  10. Using fractional order method to generalize strengthening generating operator buffer operator and weakening buffer operator

    OpenAIRE

    Wu, L.; Liu, S.; Yang, Yingjie

    2016-01-01

    Traditional integer order buffer operator is extended to fractional order buffer operator, the corresponding relationship between the weakening buffer operator and the strengthening buffer operator is revealed. Fractional order buffer operator not only can generalize the weakening buffer operator and the strengthening buffer operator, but also realize tiny adjustment of buffer effect. The effectiveness of GM(1,1) with the fractional order buffer operator is validated by six cases.

  11. Deer use of riparian zones and adjacent pine plantations in Texas

    Science.gov (United States)

    Micah L. Poteet; Ronald E. Thill; R. Montague Whiting; R. Lee Rayburn

    1996-01-01

    The authors monitored white-tailed deer (Odocoileus virginianus) use of riparian zones (RZ’s) and adjacent pine plantations of 3 age classes (young, 1 to 3 years old; intermediate, 5 to 7 years old; and older, 9 to 13 years old) using radio telemetry for 2 years on a 1,300 ha study area near Alto, TX. Riparian zones comprised 22.0 percent of the area; young,...

  12. Effects of buffer thickness on ATW blanket performances

    International Nuclear Information System (INIS)

    Yang, Won Sik

    2001-01-01

    This paper presents the preliminary results of target and buffer design studies for a lead-bismuth eutectic (LBE) cooled accelerator transmutation of waste (ATW) system, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using an 840 MWt LBE cooled ATW design, the effects of buffer thickness on the blanket performances have been studied. Varying the buffer thickness for a given blanket configuration, system performances have been estimated by a series of calculations using MCNPX and REBUS-3 codes. The effects of source importance change are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. As the irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. The results show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable

  13. How do riparian woody seedlings survive seasonal drought?

    Science.gov (United States)

    Stella, John C; Battles, John J

    2010-11-01

    In semi-arid regions, a major population limitation for riparian trees is seedling desiccation during the dry season that follows annual spring floods. We investigated the stress response of first-year pioneer riparian seedlings to experimental water table declines (0, 1 and 3 cm day(-1)), focusing on the three dominant cottonwood and willows (family Salicaceae) in California's San Joaquin Basin. We analyzed growth and belowground allocation response to water stress, and used logistic regression to determine if these traits had an influence on individual survival. The models indicate that high root growth (>3 mm day(-1)) and low shoot:root ratios (water-use efficiency for surviving water stress. Both S. gooddingii and sandbar willow (S. exigua) reduced leaf size from controls, whereas Fremont cottonwood (Populus fremontii) sustained a 29% reduction in specific leaf area (from 13.4 to 9.6 m(2) kg(-1)). The functional responses exhibited by Goodding's willow, the more drought-tolerant species, may play a role in its greater relative abundance in dry regions such as the San Joaquin Basin. This study highlights the potential for a shift in riparian forest composition. Under a future drier climate regime or under reduced regulated river flows, our results suggest that willow establishment will be favored over cottonwood.

  14. Water, land, climate change and agrarian livelihood in an arid region riparian corridor: Rayón, Sonora, Mexico

    Science.gov (United States)

    Lee, R.; Scott, C. A.; Curl, K.; House-Peters, L.; Buechler, S.

    2012-12-01

    Results of recent fieldwork in Rayón, Sonora, Mexico (funded by NSF's "Strengthening Resilience of Arid Region Riparian Corridors") indicate that the coupled natural and human (CNH) system that has persisted since the town's founding in 1626 is being degraded and destabilised by a confluence of social and ecological pressures. System change or loss of key system services and products has important implications for ecological services and human economic activity in the riparian corridor. Less water quantity is the primary factor responsible for driving system degradation and change. Drought caused by climate change is widely perceived by agriculturists as responsible for reduced water quantity in the riparian area. Reductions in water quantity are so severe that the once perennial Rio San Miguel did not run during 2012's summer months for the first time in residents' memory. Ninety-percent of wells are dry. Fields irrigated by surface-water acequias were not planted. Starvation or dehydration has thinned herd sizes. Residents fear they will lose the ability to practice their traditional livelihoods: ranching, farming and cheese production. Drought conditions and resource management in response to climatic change have had a net negative impact on ecological services. Agriculturists have responded to less forage and pasture for cattle by clearing mesquite forests, putting land into production, and increasing water demand. From interviews it appears this process is cyclical: agriculturists widely believe access to more water or an end to the drought are the only ways to improve conditions. Interviews also reveal (a) agriculturists view technology, especially that which is able to improve water-use efficiency, as means to reduce stress in the CNH system and (b) a holistic view that couples natural well-being to human well-being is absent from the majority of respondents' worldviews. Technological and adoption of holistic perceptions are adaptations that may potentially

  15. Common data buffer system. [communication with computational equipment utilized in spacecraft operations

    Science.gov (United States)

    Byrne, F. (Inventor)

    1981-01-01

    A high speed common data buffer system is described for providing an interface and communications medium between a plurality of computers utilized in a distributed computer complex forming part of a checkout, command and control system for space vehicles and associated ground support equipment. The system includes the capability for temporarily storing data to be transferred between computers, for transferring a plurality of interrupts between computers, for monitoring and recording these transfers, and for correcting errors incurred in these transfers. Validity checks are made on each transfer and appropriate error notification is given to the computer associated with that transfer.

  16. Shifting stream planform state decreases stream productivity yet increases riparian animal production

    Science.gov (United States)

    Venarsky, Michael P.; Walters, David M.; Hall, Robert O.; Livers, Bridget; Wohl, Ellen

    2018-01-01

    In the Colorado Front Range (USA), disturbance history dictates stream planform. Undisturbed, old-growth streams have multiple channels and large amounts of wood and depositional habitat. Disturbed streams (wildfires and logging production, emerging aquatic insect flux, and riparian spider biomass. Organic matter and macroinvertebrate production did not differ among sites per unit area (m−2), but values were 2 ×–21 × higher in undisturbed reaches per unit of stream valley (m−1 valley) because total stream area was higher in undisturbed reaches. Insect emergence was similar among streams at the per unit area and per unit of stream valley. However, rescaling insect emergence to per meter of stream bank showed that the emerging insect biomass reaching the stream bank was lower in undisturbed sites because multi-channel reaches had 3 × more stream bank than single-channel reaches. Riparian spider biomass followed the same pattern as emerging aquatic insects, and we attribute this to bottom-up limitation caused by the multi-channeled undisturbed sites diluting prey quantity (emerging insects) reaching the stream bank (riparian spider habitat). These results show that historic landscape disturbances continue to influence stream and riparian communities in the Colorado Front Range. However, these legacy effects are only weakly influencing habitat-specific function and instead are primarily influencing stream–riparian community productivity by dictating both stream planform (total stream area, total stream bank length) and the proportional distribution of specific habitat types (pools vs riffles).

  17. Riparian landscape management in the midstream of Ciliwung River as supporting Water Sensitive Cities program with priority of productive landscape

    Science.gov (United States)

    Noviandi, T. U. Z.; Kaswanto, R. L.; Arifin, H. S.

    2017-10-01

    Nowadays, Ciliwung River is facing problem of the settlement occupation in its riparian zones. This phenomenon caused ecological damage in riparian, so it can aggravate the disaster of annual flooding in Jakarta. As an effort to control this catastrophe, riparian landscape management of Ciliwung River is needed. Based on its topography, Ciliwung River is divided into three segments, there are the upstream, the midstream, and the downstream. Data shows that riparian in the midstream is the largest area, it covers more than 60% of the total riparian area. This segment is very important to be managed in order to reduce runoff towards the downstream. The method used was comparing many standards to get the ideal riparian width in the midstream, which is 50 m for urban areas and 100 m for outside the urban areas. Next method was analyzing spatially to get riparian landscape characteristic of Ciliwung River. The result showed that 37.11% of riparian zones in the midstream had occupied by settlement. Analysis of riparian function and utilization had held by using Analytical Hierarchy Process. Priority of riparian function in the midstream of Ciliwung River is production. This can be realized with the plan of community garden or inland fisheries. Riparian landscape management in the midstream aims to support the food consumption diversification, and maximize the function of water catchment and water retention in order to support the program of Water Sensitive Cities.

  18. Heuristics for the Buffer Allocation Problem with Collision Probability Using Computer Simulation

    Directory of Open Access Journals (Sweden)

    Eishi Chiba

    2015-01-01

    Full Text Available The standard manufacturing system for Flat Panel Displays (FPDs consists of a number of pieces of equipment in series. Each piece of equipment usually has a number of buffers to prevent collision between glass substrates. However, in reality, very few of these buffers seem to be used. This means that redundant buffers exist. In order to reduce cost and space necessary for manufacturing, the number of buffers should be minimized with consideration of possible collisions. In this paper, we focus on an in-line system in which each piece of equipment can have any number of buffers. In this in-line system, we present a computer simulation method for the computation of the probability of a collision occurring. Based on this method, we try to find a buffer allocation that achieves the smallest total number of buffers under an arbitrarily specified collision probability. We also implement our proposed method and present some computational results.

  19. The dark side of suibsidies: quantifying contaminant exposure to riparian predators via stream insects

    Science.gov (United States)

    Aquatic insects provide a critical nutrient subsidy to riparian food webs, yet their role as vectors of contaminants to terrestrial ecosystems is poorly understood. We investigated relationships between aquatic (resource utilization) and contaminant exposure for a riparian invert...

  20. Radionuclide transport along a boreal hill slope - elevated soil water concentrations in riparian forest soils

    Energy Technology Data Exchange (ETDEWEB)

    Lidman, Fredrik; Boily, Aasa; Laudon, Hjalmar [Dept. of Forest Ecology and Management, Swedish University of Agricultural Sciences, 901 83 Umeaa (Sweden); Koehler, Stephan J. [Dept. of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, P.O. 7050, 750 07 Uppsala (Sweden)

    2014-07-01

    The transport of radionuclides from forest ecosystems and out into surface waters is a crucial process for understanding the long-term fate of radionuclides in the boreal landscape. Boreal forests are typically dominated by podzol soils, but the streams draining the forests are often lined by highly organic, often peat-like soils, which the radionuclides must pass through in order to reach the stream. This so-called riparian zone therefore represents a fundamentally different biogeochemical environment than ordinary forest soils, e.g. by exhibiting significantly lower pH and higher concentrations of organic colloids, which significantly can affect the mobility of many radionuclides. Since the riparian zone is the last terrestrial environment that the groundwater is in contact with before it enters the stream, previous research has demonstrated its profound impact on the stream water chemistry. Hence, the riparian soils should also be important for the transport and accumulation of radionuclides. Therefore, soil water was sampled using suction lysimeters installed at different depths along a 22 m long forested hill slope transect in northern Sweden, following the flow pathway of the groundwater from the uphill podzol to the riparian zone near the stream channel. The analyses included a wide range of hydrochemical parameters and many radiologically important elements, e.g. U, Th, Ni, C, Sr, Cs, REEs and Cl. The sampling was repeated ten times throughout a year in order to also capture the temporal variability of the soil water chemistry. The water chemistry of the investigated transect displayed a remarkable change as the groundwater approached the stream channel. Strongly increased concentrations of many elements were observed in the riparian soils. For instance, the concentrations of Th were more than 100 times higher than in the riparian zone than in the uphill forest, suggesting that the riparian zone may be a hotspot for radionuclide accumulation. The reason

  1. [Distribution pattern of rare plants along riparian zone and its implication for conservation in Shennongjia area].

    Science.gov (United States)

    Jiang, Mingxi; Deng, Hongbing; Cai, Qinghua

    2002-11-01

    Due to the importance of riparian zone in maintaining and protecting regional biodiversity, more and more ecologists paid their attentions to riparian zone, and had been aware of the important effects of riparian zone in basic study and practical management. In this study, forty sampling belts (10 m x 100 m) parallel to the bank of Xiangxi River at different elevations in Shennongjia area were selected to investigate the riparian vegetation and rare plants. Fourteen species of rare plants were found in riparian zone, accounting for 42.4% of total rare plant species in Shennongjia area. The main distribution range of the fourteen rare plant species was the mixed evergreen and deciduous broadleaved forest at elevation of 1200-1800 m, where species diversity of plant community was the maximum at the moderate elevation. Fourteen rare plant species could be divided into three groups against the elevation, namely low elevation species group, moderate elevation species group, and high elevation group. In the paper, the authors discussed the reasons forming the distribution pattern of rare plant species, and pointed out the important function of riparian zone on rare plant species protection.

  2. From leaf to basin: evaluating the impacts of introduced plant species on evapotranspiration fluxes from riparian ecosystems in the southwestern U.S

    Science.gov (United States)

    Hultine, K. R.; Bush, S.; Nagler, P. L.; Morino, K.; Burtch, K.; Dennison, P. E.; Glenn, E. P.; Ehleringer, J.

    2010-12-01

    Global change processes such as climate change and intensive land use pose significant threats to water resources, particularly in arid regions where potential evapotranspiration far exceeds annual rainfall. Potentially compounding these shortages is the progressive expansion of introduced plant species in riparian areas along streams, canals and rivers in geographically arid regions. The question of whether these invasive species have had or will have impacts on water resources is currently under intense debate. We identify a framework for assessing when and where introduced riparian plant species are likely to have the highest potential impact on hydrologic fluxes of arid and semi-arid river systems. We focus on three introduced plant systems that currently dominate southwestern U.S. riparian forests: tamarisk (Tamarix spp.), Russian olive (Eleagnus angustifolia), and Russian knapweed (Acroptilon repens). Our framework focuses on two main criteria: 1) the ecophysiological traits that promote establishment of invasive species across environmental gradients, and 2) an assessment of how hydrologic fluxes are altered by the establishment of introduced species at varying scales. The framework identifies when and where introduced species should have the highest potential impact on the water cycle. This framework will assist land managers and policy makers with restoration and conservation priorities to preserve water resources and valued riparian habitat given limited economic resources.

  3. Riparian Communities along Longitudinal Gradients in Mexico's Northeastern San Juan River

    OpenAIRE

    Guerra, San Juana; Lizárraga-Mendiola, Liliana; Návar, José

    2016-01-01

    Abstract: This research was conducted in three major tributaries of Mexico's northeast San Juan River with the major objectives of: (a) describing the diversity-abundance of riparian trees, benthic insects and fish faunal communities and (b) associating the fish and benthic insect communities to riparian tree communities, flow quality, and discharge parameters along a longitudinal gradient of water stress. Regardless of the high spatial variability, two gradients could be identified using mul...

  4. Development and application of multi-proxy indices of land use change for riparian soils in southern New England, USA.

    Science.gov (United States)

    Ricker, M C; Donohue, S W; Stolt, M H; Zavada, M S

    2012-03-01

    Understanding the effects of land use on riparian systems is dependent upon the development of methodologies to recognize changes in sedimentation related to shifts in land use. Land use trends in southern New England consist of shifts from forested precolonial conditions, to colonial and agrarian land uses, and toward modern industrial-urban landscapes. The goals of this study were to develop a set of stratigraphic indices that reflect these land use periods and to illustrate their applications. Twenty-four riparian sites from first- and second-order watersheds were chosen for study. Soil morphological features, such as buried surface horizons (layers), were useful to identify periods of watershed instability. The presence of human artifacts and increases in heavy metal concentration above background levels, were also effective indicators of industrial-urban land use periods. Increases and peak abundance of non-arboreal weed pollen (Ambrosia) were identified as stratigraphic markers indicative of agricultural land uses. Twelve 14C dates from riparian soils indicated that the rise in non-arboreal pollen corresponds to the start of regional deforestation (AD 1749 +/- 56 cal yr; mean +/- 2 SD) and peak non-arboreal pollen concentration corresponds to maximum agricultural land use (AD 1820 +/- 51 cal yr). These indices were applied to elucidate the impact of land use on riparian sedimentation and soil carbon (C) dynamics. This analysis indicated that the majority of sediment and soil organic carbon (SOC) stored in regional riparian soils is of postcolonial origins. Mean net sedimentation rates increased -100-fold during postcolonial time periods, and net SOC sequestration rates showed an approximate 200-fold increase since precolonial times. These results suggest that headwater riparian zones have acted as an effective sink for alluvial sediment and SOC associated with postcolonial land use.

  5. Woody riparian vegetation response to different alluvial water table regimes

    Science.gov (United States)

    Shafroth, P.B.; Stromberg, J.C.; Patten, D.T.

    2000-01-01

    Woody riparian vegetation in western North American riparian ecosystems is commonly dependent on alluvial groundwater. Various natural and anthropogenic mechanisms can cause groundwater declines that stress riparian vegetation, but little quantitative information exists on the nature of plant response to different magnitudes, rates, and durations of groundwater decline. We observed groundwater dynamics and the response of Populus fremontii, Salix gooddingii, and Tamarix ramosissima saplings at 3 sites between 1995 and 1997 along the Bill Williams River, Arizona. At a site where the lowest observed groundwater level in 1996 (-1.97 m) was 1.11 m lower than that in 1995 (-0.86 m), 92-100% of Populus and Salix saplings died, whereas 0-13% of Tamarix stems died. A site with greater absolute water table depths in 1996 (-2.55 m), but less change from the 1995 condition (0.55 m), showed less Populus and Salix mortality and increased basal area. Excavations of sapling roots suggest that root distribution is related to groundwater history. Therefore, a decline in water table relative to the condition under which roots developed may strand plant roots where they cannot obtain sufficient moisture. Plant response is likely mediated by other factors such as soil texture and stratigraphy, availability of precipitation-derived soil moisture, physiological and morphological adaptations to water stress, and tree age. An understanding of the relationships between water table declines and plant response may enable land and water managers to avoid activities that are likely to stress desirable riparian vegetation.

  6. Evaluating resilience of DNP3-controlled SCADA systems against event buffer flooding

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Guanhua [Los Alamos National Laboratory; Nicol, David M [UNIV OF IL; Jin, Dong [UNIV OF IL

    2010-12-16

    The DNP3 protocol is widely used in SCADA systems (particularly electrical power) as a means of communicating observed sensor state information back to a control center. Typical architectures using DNP3 have a two level hierarchy, where a specialized data aggregator device receives observed state from devices within a local region, and the control center collects the aggregated state from the data aggregator. The DNP3 communication between control center and data aggregator is asynchronous with the DNP3 communication between data aggregator and relays; this leads to the possibility of completely filling a data aggregator's buffer of pending events, when a relay is compromised or spoofed and sends overly many (false) events to the data aggregator. This paper investigates how a real-world SCADA device responds to event buffer flooding. A Discrete-Time Markov Chain (DTMC) model is developed for understanding this. The DTMC model is validated by a Moebius simulation model and data collected on real SCADA testbed.

  7. Plant species distribution in relation to water-table depth and soil redox potential in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; John E. Baham

    2006-01-01

    The distribution of riparian plant species is largely driven by hydrologic and soil variables, and riparian plant communities frequently occur in relatively distinct zones along streamside elevational and soil textural gradients. In two montane meadows in northeast Oregon, USA, we examined plant species distribution in three riparian plant communities¡ªdefined as wet,...

  8. Simulation of Soil Quality with Riparian Forests and Cultivated with Sugarcane

    Science.gov (United States)

    da Silva, Luiz Gabriel; Colato, Alexandre; Casagrande, José Carlos; Soares, Marcio Roberto; Perissatto Meneghin, Silvana

    2013-04-01

    Riparian forests are entrusted with important hydrological functions, such as riparian zone protection, filtering sediments and nutrients and mitigation of the amount of nutrients and xenobiotic molecules from the surrounding agro ecosystems. The soil was sampled in the depths of 0-0,2 and 0.2-0.4 m and its chemical (nutrient content and organic matter, cationic exchange capacity - CEC, sum of bases-SB, bases saturation, V%, and aluminum saturation, m%); physical (particle size distribution, density and porosity) and microbiological attributes (basal respiration and microbial biomass) were determined. This work aimed to study the liner method of combining data, figures of merit (FoM), weighing process and the scoring functions developed by Wymore and asses the quality of the soil (SQI) by means of chemical, physical and microbiological soil attributes, employing the additive pondered model for two areas of riparian forest at different stages of ecological succession and an adjacent area cultivated with sugar cane, located on the dam shores of Sugar Mill Saint Lucia-Araras/SP. Some hierarchical functions containing FoMs and their parameters were constructed, and from them weights were assigned to each FoM and parameter, in a way that cluster of structures with the same FoMs and parameters with different weights were formed. These clusters were used to calculate the SQI for all vegetal formations considering two types of soil (Oxisol and Podzol), in that way, the SQI was calculated for each combination of vegetation and soil. The SQIs values were usually higher in the oldest riparian forest, while the recent riparian forest showed the smallest SQI values, for both types of soil. The variation of values within a combination vegetation/soil was also different between all combinations, being that the set of values from the oldest riparian forest presented the lowest amplitude. It was also observed that the Oxisols, regardless of the vegetation, presented higher SQIs

  9. Buffer protection in the installation phase

    International Nuclear Information System (INIS)

    Wimelius, Hans; Pusch, Roland

    2008-12-01

    The research and development of the design and construction of the SKB's repository for final disposal of spent reactor fuel is conducted along several paths ('lines'). Issues concerning the bedrock are dealt with in the 'rock line' and those related to buffer and backfill in deposition holes and tunnels are considered in the 'buffer line' and 'backfill line', respectively. These lines also deal with sub-activities that are coupled to several other lines. One of them includes development of techniques for protecting buffer blocks from moisture and water in the installation phase. Techniques and methods for placement and removal of the 'buffer protection sheet' are dealt with in the 'buffer line'. The removal is, however, considered as being part of the backfilling sequence. Since the performance of the sheet is of fundamental importance to the placement and function of the buffer it deserves particular attention. Thus, the removal of the rubber sheet that serves to protect the buffer blocks in the installation phase may be difficult and can cause significant problems that may require retrieval of already placed canister, buffer and backfill. These matters are in focus in the present report. Arrangements for protecting already placed buffer blocks from moist air and water have been tested in earlier large-scale experiments, i.e. the Prototype Repository project at Aespoe but the experience from them has called for more effective protection of the clay blocks as described in the present report. Focus is on the construction of foundation components at the bottom of the deposition holes required for establishing a tight seal between rock and buffer blocks, and on the protection sheet and arrangements for limiting water pressure on it. Special attention is paid to the drainage of the space between rock and protection sheet that is necessary for avoiding failure of the sheet and to systems for achieving this and for providing alarm signals if the allowed pressure is

  10. Extrusion and erosion of bentonite buffer material in a flow-through, horizontal, artificial fracture system

    International Nuclear Information System (INIS)

    Schatz, Timothy; Kanerva, Noora; Martikainen, Jari

    2012-01-01

    Document available in extended abstract form only. One scenario of interest for the long-term safety assessment of a spent nuclear fuel repository involves the loss of bentonite buffer material through contact with dilute groundwater at a transmissive fracture interface [SKB 2011, Posiva 2012]. In order to simulate the potential extrusion/erosion behaviour of bentonite buffer material in such an environment, a series of small-scale, flow-through, artificial fracture experiments were performed in which swelling clay material could extrude/erode into a well defined, system (see Figure 1). The fracture dimensions were 24 cm (length) x 24 cm (width) x 1 mm (aperture) and the compacted sample dimensions were 2 cm (height) x 2 cm (diameter). Extrusion/erosion effects were analysed against solution chemistry (salt concentration and composition), material composition (sodium montmorillonite and admixtures with calcium montmorillonite), and flow velocity. No erosion was observed for sodium montmorillonite against solution compositions from 10 to 0.5 g/L NaCl. Comparatively, most reports in the literature indicate that a concentration of 0.5 g/L NaCl (8.6 mM) is below, in some cases well below, the (experimentally observed) critical coagulation concentration (CCC) for the colloidal sodium montmorillonite/sodium chloride system [Garcia-Garcia et al. 2007]. It was also the case that no erosion was observed for 50/50 calcium/sodium montmorillonite against 0.5 g/L NaCl. Overall, the results of the flow-through, artificial fracture tests, indicate stability to erosion down to a dilute concentration range between 8 to 4 mM NaCl for both sodium and 50/50 calcium/sodium montmorillonite. These limits compare favorably to the erosion stability limits observed by Birgersson et al. [2009] in the case of the latter material but less so for the former. A number of tests were conducted for which measurable erosion was observed. The calculated mass loss rates for these tests, expressed in

  11. Plant biomass and species composition along an environmental gradient in montane riparian meadows

    Science.gov (United States)

    Kathleen A. Dwire; J. Boone Kauffman; E. N. Jack Brookshire; John E. Baham

    2004-01-01

    In riparian meadows, narrow zonation of the dominant vegetation frequently occurs along the elevational gradient from the stream edge to the floodplain terrace. We measured plant species composition and above- and belowground biomass in three riparian plant communities - a priori defined as wet, moist, and dry meadow - along short streamside topographic gradients in...

  12. Effects of node buffer and capacity on network traffic

    International Nuclear Information System (INIS)

    Ling Xiang; Ding Jian-Xun; Hu Mao-Bin

    2012-01-01

    In this paper, we study the optimization of network traffic by considering the effects of node buffer ability and capacity. Two node buffer settings are considered. The node capacity is considered to be proportional to its buffer ability. The node effects on network traffic systems are studied with the shortest path protocol and an extension of the optimal routing [Phys. Rev. E 74 046106 (2006)]. In the diagrams of flux—density relationships, it is shown that a nodes buffer ability and capacity have profound effects on the network traffic

  13. Effects of Channelisation, Riparian Structure and Catchment Area on Physical Habitats in Small Lowland Streams

    DEFF Research Database (Denmark)

    Pedersen, Morten Lauge

    2009-01-01

    Rivers and streams form a longitudinal network in which physical conditions and biological processes change through the river system. Geomorphology, topography, geology and hydraulic conditions change from site to site within the river system, thereby creating a complex network of reaches that ar.......e. a confined and steep valley (V-shaped) is less likely to be used for agricultural production compared to a broad valley. The results are useful to water managers, who seek to identify natural and impacted physical conditions in large river systems....... that are dominated by a hierarchy of physical processes. The complexity is further enhanced by local human alteration of the physical structure, natural processes and alteration of the riparian areas. The aim of the study was to analyse variations in land use and riparian characteristics along small Danish streams...... and to determine the effect of channelisation on physical habitats. Physical stream characteristics were measured in 149 stream small and medium sized Danish streams (catchment area: 0.1 to 67.2 km2). The measured physical parameters included discharge, stream slope, width, depth, current velocity, substrata...

  14. Effects of increased flooding on riparian vegetation: Field experiments simulating climate change along five European lowland streams.

    Science.gov (United States)

    Garssen, Annemarie G; Baattrup-Pedersen, Annette; Riis, Tenna; Raven, Bart M; Hoffman, Carl Christian; Verhoeven, Jos T A; Soons, Merel B

    2017-08-01

    In many parts of the world, the magnitude and frequency of cold-season precipitation are expected to increase in the near future. This will result in an increased magnitude and duration of winter and spring flooding by rain-fed streams and rivers. Such climate-driven increases in flooding are likely to affect riparian plant communities, but future vegetation changes are hard to predict due to current lack of data. To fill this knowledge gap, we experimentally modified the hydrology of five streams across three countries in north-western Europe during late winter/early spring over a period of 3 years. We assessed the responses in riparian plant species richness, biomass, plant-available nitrogen and phosphorus and seed deposition to increased flooding depth (+18 cm on average at the lowest positions along the riparian gradient) and prolonged flooding duration (6 weeks on average). After 3 years of increased flooding, there was an overall decline in riparian species richness, while riparian plant biomass increased. Extractable soil nitrogen and phosphorus also increased and are likely to have contributed to the increased biomass. Increased flooding resulted in the arrival of more seeds of additional species to the riparian zone, thereby potentially facilitating the shifts in riparian plant species composition we observed. The results of our concerted experimental effort demonstrate that changes in stream riparian plant communities can occur rapidly following increased winter flooding, leading to strong reductions in plant species diversity. © 2017 The Authors. Global Change Biology published by John Wiley & Sons Ltd.

  15. Riparian restoration in the context of Tamarix control in the western United States: Chapter 23

    Science.gov (United States)

    Shafroth, Patrick B.; Merritt, David M.; Briggs, Mark K.; Beauchamp, Vanessa B.; Lair, Kenneth D.; Scott, Michael L.; Sher, Anna; Sher, Anna; Quigley, Martin F.

    2013-01-01

    This chapter focuses on the restoration of riparian systems in the context of Tamarix control—that is, Tamarix-dominated sites are converted to a replacement vegetation type that achieves specific management goals and helps return parts of the system to a desired and more natural state or dynamic. It reviews research related to restoring native riparian vegetation following tamarix control or removal. The chapter begins with an overview of objective setting and the planning of tamarix control and proceeds by emphasizing the importance of considering site-specific factors and of context in selecting and prioritizing sites for restoration. In particular, it considers valley and bottomland geomorphology, along with river flow regime and associated fluvial disturbance, surface water and groundwater availability, and soil salinity and texture. The chapter concludes with a discussion of costs and benefits associated with active, passive, and combined ecological restoration approaches, as well as the key issues to consider in carrying out restoration projects at a range of scales.

  16. Shifting stream planform state decreases stream productivity yet increases riparian animal production

    Science.gov (United States)

    Venarsky, Michael P.; Walters, David M.; Hall, Robert O.; Livers, Bridget; Wohl, Ellen

    2018-01-01

    In the Colorado Front Range (USA), disturbance history dictates stream planform. Undisturbed, old-growth streams have multiple channels and large amounts of wood and depositional habitat. Disturbed streams (wildfires and logging tested how these opposing stream states influenced organic matter, benthic macroinvertebrate secondary production, emerging aquatic insect flux, and riparian spider biomass. Organic matter and macroinvertebrate production did not differ among sites per unit area (m−2), but values were 2 ×–21 × higher in undisturbed reaches per unit of stream valley (m−1 valley) because total stream area was higher in undisturbed reaches. Insect emergence was similar among streams at the per unit area and per unit of stream valley. However, rescaling insect emergence to per meter of stream bank showed that the emerging insect biomass reaching the stream bank was lower in undisturbed sites because multi-channel reaches had 3 × more stream bank than single-channel reaches. Riparian spider biomass followed the same pattern as emerging aquatic insects, and we attribute this to bottom-up limitation caused by the multi-channeled undisturbed sites diluting prey quantity (emerging insects) reaching the stream bank (riparian spider habitat). These results show that historic landscape disturbances continue to influence stream and riparian communities in the Colorado Front Range. However, these legacy effects are only weakly influencing habitat-specific function and instead are primarily influencing stream–riparian community productivity by dictating both stream planform (total stream area, total stream bank length) and the proportional distribution of specific habitat types (pools vs riffles).

  17. Effects of watershed and riparian zone characteristics on nutrient concentrations in the River Scheldt Basin

    Directory of Open Access Journals (Sweden)

    J. Meynendonckx

    2006-01-01

    Full Text Available The relative influence of a set of watershed characteristics on surface water nutrient concentrations was examined in 173 watersheds within two subcatchments (Upper-Scheldt and Nete of the River Scheldt Basin (Flanders, Belgium. Each watershed was described by seasonal rainfall, discharge loading of point sources, morphological characteristics (area, average slope, drainage density, elongation, land use and soil properties (soil texture and drainage. Partial regression analysis revealed that soil drainage variables had the strongest influence on nutrient concentrations. Additional influence was exerted by land use and point source loading variables. Nitrate concentrations were positively correlated with effluent loadings coming from wastewater treatment plants and with the area of agricultural land. Phosphate concentrations were best explained by effluent loadings of industrial point sources and by the area of urban land. Land use close to the river was not a better predictor of nitrate and phosphate concentrations than land use away from the river. This suggests that the mediating impact of riparian zones is rather explained by the hydrologic pathways within the buffer strip.

  18. Basal buffer systems for a newly glycosylated recombinant human interferon-β with biophysical stability and DoE approaches.

    Science.gov (United States)

    Kim, Nam Ah; Song, Kyoung; Lim, Dae Gon; Hada, Shavron; Shin, Young Kee; Shin, Sangmun; Jeong, Seong Hoon

    2015-10-12

    The purpose of this study was to develop a basal buffer system for a biobetter version of recombinant human interferon-β 1a (rhIFN-β 1a), termed R27T, to optimize its biophysical stability. The protein was pre-screened in solution as a function of pH (2-11) using differential scanning calorimetry (DSC) and dynamic light scattering (DLS). According to the result, its experimental pI and optimal pH range were 5.8 and 3.6-4.4, respectively. Design of experiment (DoE) approach was developed as a practical tool to aid formulation studies as a function of pH (2.9-5.7), buffer (phosphate, acetate, citrate, and histidine), and buffer concentration (20 mM and 50 mM). This method employed a weight-based procedure to interpret complex data sets and to investigate critical key factors representing protein stability. The factors used were Tm, enthalpy, and relative helix contents which were obtained by DSC and Fourier Transform Infrared spectroscopy (FT-IR). Although the weights changed by three responses, objective functions from a set of experimental designs based on four buffers were highest in 20 mM acetate buffer at pH 3.6 among all 19 scenarios tested. Size exclusion chromatography (SEC) was adopted to investigate accelerated storage stability in order to optimize the pH value with susceptible stability since the low pH was not patient-compliant. Interestingly, relative helix contents and storage stability (monomer remaining) increased with pH and was the highest at pH 4.0. On the other hand, relative helix contents and thermodynamic stability decreased at pH 4.2 and 4.4, suggesting protein aggregation issues. Therefore, the optimized basal buffer system for the novel biobetter was proposed to be 20 mM acetate buffer at pH 3.8±0.2. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Comparison of leaf-on and leaf-off ALS data for mapping riparian tree species

    Science.gov (United States)

    Laslier, Marianne; Ba, Antoine; Hubert-Moy, Laurence; Dufour, Simon

    2017-10-01

    Forest species composition is a fundamental indicator of forest study and management. However, describing forest species composition at large scales and of highly diverse populations remains an issue for which remote sensing can provide significant contribution, in particular, Airborne Laser Scanning (ALS) data. Riparian corridors are good examples of highly valuable ecosystems, with high species richness and large surface areas that can be time consuming and expensive to monitor with in situ measurements. Remote sensing could be useful to study them, but few studies have focused on monitoring riparian tree species using ALS data. This study aimed to determine which metrics derived from ALS data are best suited to identify and map riparian tree species. We acquired very high density leaf-on and leaf-off ALS data along the Sélune River (France). In addition, we inventoried eight main riparian deciduous tree species along the study site. After manual segmentation of the inventoried trees, we extracted 68 morphological and structural metrics from both leaf-on and leaf-off ALS point clouds. Some of these metrics were then selected using Sequential Forward Selection (SFS) algorithm. Support Vector Machine (SVM) classification results showed good accuracy with 7 metrics (0.77). Both leaf-on and leafoff metrics were kept as important metrics for distinguishing tree species. Results demonstrate the ability of 3D information derived from high density ALS data to identify riparian tree species using external and internal structural metrics. They also highlight the complementarity of leaf-on and leaf-off Lidar data for distinguishing riparian tree species.

  20. Integrated monitoring of hydrogeomorphic, vegetative, and edaphic conditions in riparian ecosystems of Great Basin National Park, Nevada

    Science.gov (United States)

    Beever, Erik A.; Pyke, D.A.

    2004-01-01

    In semiarid regions such as the Great Basin, riparian areas function as oases of cooler and more stable microclimates, greater relative humidity, greater structural complexity, and a steady flow of water and nutrients relative to upland areas. These qualities make riparian areaʼs attractive not only to resident and migratory wildlife, but also to visitors in recreation areas such as Great Basin National Park in the Snake Range, east-central Nevada. To expand upon the system of ten permanent plots sampled in 1992 (Smith et al. 1994) and 2001 (Beever et al. in press), we established a collection of 31 cross-sectional transects of 50-m width across the mainstems of Strawberry, Lehman, Baker, and Snake creeks. Our aims in this research were threefold: a) map riparian vegetative communities in greater detail than had been done by past efforts; b) provide a monitoring baseline of hydrogeomorphology; structure, composition, and function of upland- and riparianassociated vegetation; and edaphic properties potentially sensitive to management; and c) test whether instream conditions or physiographic variables predicted vegetation patterns across the four target streams.

  1. A THEORETICAL DISCUSSION OF THE ECONOMIC EFFECTS OF BUFFER STOCKS AND BUFFER FUNDS

    OpenAIRE

    Simmons, Phil

    1988-01-01

    It has been established that the absence of risk markets justifies market intervention in principle. The form of intervention that has been discussed most widely in the literature is the buffer stock. This paper points out that other forms of intervention, specifically buffer funds, are likely to perform better. The analysis shows that buffer funds are likely to outperform buffer stocks because they address market failure more directly. A sub-theme developed in this paper is that since buffer...

  2. Sensitivity Analysis of a Riparian Vegetation Growth Model

    Directory of Open Access Journals (Sweden)

    Michael Nones

    2016-11-01

    Full Text Available The paper presents a sensitivity analysis of two main parameters used in a mathematic model able to evaluate the effects of changing hydrology on the growth of riparian vegetation along rivers and its effects on the cross-section width. Due to a lack of data in existing literature, in a past study the schematization proposed here was applied only to two large rivers, assuming steady conditions for the vegetational carrying capacity and coupling the vegetal model with a 1D description of the river morphology. In this paper, the limitation set by steady conditions is overcome, imposing the vegetational evolution dependent upon the initial plant population and the growth rate, which represents the potential growth of the overall vegetation along the watercourse. The sensitivity analysis shows that, regardless of the initial population density, the growth rate can be considered the main parameter defining the development of riparian vegetation, but it results site-specific effects, with significant differences for large and small rivers. Despite the numerous simplifications adopted and the small database analyzed, the comparison between measured and computed river widths shows a quite good capability of the model in representing the typical interactions between riparian vegetation and water flow occurring along watercourses. After a thorough calibration, the relatively simple structure of the code permits further developments and applications to a wide range of alluvial rivers.

  3. Modeling and Validating Time, Buffering, and Utilization of a Large-Scale, Real-Time Data Acquisition System

    CERN Document Server

    AUTHOR|(SzGeCERN)756497; The ATLAS collaboration; Garcia Garcia, Pedro Javier; Vandelli, Wainer; Froening, Holger

    2017-01-01

    Data acquisition systems for large-scale high-energy physics experiments have to handle hundreds of gigabytes per second of data, and are typically realized as specialized data centers that connect a very large number of front-end electronics devices to an event detection and storage system. The design of such systems is often based on many assumptions, small-scale experiments and a substantial amount of over-provisioning. In this work, we introduce a discrete event-based simulation tool that models the data flow of the current ATLAS data acquisition system, with the main goal to be accurate with regard to the main operational characteristics. We measure buffer occupancy counting the number of elements in buffers, resource utilization measuring output bandwidth and counting the number of active processing units, and their time evolution by comparing data over many consecutive and small periods of time. We perform studies on the error of simulation when comparing the results to a large amount of real-world ope...

  4. Modeling and Validating Time, Buffering, and Utilization of a Large-Scale, Real-Time Data Acquisition System

    CERN Document Server

    AUTHOR|(SzGeCERN)756497; The ATLAS collaboration; Garcia Garcia, Pedro Javier; Vandelli, Wainer; Froening, Holger

    2017-01-01

    Data acquisition systems for large-scale high-energy physics experiments have to handle hundreds of gigabytes per second of data, and are typically implemented as specialized data centers that connect a very large number of front-end electronics devices to an event detection and storage system. The design of such systems is often based on many assumptions, small-scale experiments and a substantial amount of over-provisioning. In this paper, we introduce a discrete event-based simulation tool that models the dataflow of the current ATLAS data acquisition system, with the main goal to be accurate with regard to the main operational characteristics. We measure buffer occupancy counting the number of elements in buffers; resource utilization measuring output bandwidth and counting the number of active processing units, and their time evolution by comparing data over many consecutive and small periods of time. We perform studies on the error in simulation when comparing the results to a large amount of real-world ...

  5. The Importance and Future Condition of Western Riparian Ecosystems as Migratory Bird Habitat

    Science.gov (United States)

    Susan K. Skagen; Rob Hazlewood; Michael L. Scott

    2005-01-01

    Riparian forests have long been considered important habitats for breeding western landbirds, and growing evidence reinforces their importance during the migratory period as well. Extensive modification of natural flow regimes, grazing, and forest clearing along many rivers in the western U.S. have led to loss and simplification of native riparian forests and to...

  6. Evaluation of methods for delineating riparian zones in a semi-arid montane watershed

    Science.gov (United States)

    Jessica A. Salo; David M. Theobald; Thomas C. Brown

    2016-01-01

    Riparian zones in semi-arid, mountainous regions provide a disproportionate amount of the available wildlife habitat and ecosystem services. Despite their importance, there is little guidance on the best way to map riparian zones for broad spatial extents (e.g., large watersheds) when detailed maps from field data or high-resolution imagery and terrain data...

  7. Riparian restoration in the Southwest: Species selection, propagation, planting methods, and case studies

    Science.gov (United States)

    David Dreesen; John Harrington; Tom Subirge; Pete Stewart; Greg Fenchel

    2002-01-01

    Riparian plant communities, though small in overall area, are among the most valuable natural areas in the Southwest. The causes of degradation of southwestern riparian zones range from excessive cattle and elk grazing in montane watersheds to invasive woody exotic species and lack of natural flooding in the cottonwood forests, "bosque," of low elevation...

  8. Dendroclimatic signals deduced from riparian versus upland forest interior pines in North Karelia, Finland

    DEFF Research Database (Denmark)

    Helama, Samuli; Arentoft, Birgitte W.; Collin-Haubensak, Olivier

    2013-01-01

    Radial growth of boreal tree species is only rarely studied in riparian habitats. Here we investigated chronologies of earlywood, latewood, and annual ring widths and blue intensity (BI; a surrogate to latewood density) from riparian lake shore and upland forest interior pines (Pinus sylvestris L...

  9. Conservation of soil, water and nutrients in surface runoff using riparian plant species.

    Science.gov (United States)

    Srivastava, Prabodh; Singh, Shipra

    2012-01-01

    Three riparian plant species viz. Cynodon dactylon (L.) Pers., Saccharum bengalensis Retz. and Parthenium hysterophorus L. were selected from the riparian zone of Kali river at Aligarh to conduct the surface runoff experiment to compare their conservation efficiencies for soil, water and nutrients (phosphorus and nitrogen). Experimental plots were prepared on artificial slopes in botanical garden and on natural slopes on study site. Selected riparian plant species showed the range of conservation values for soil and water from 47.11 to 95.22% and 44.06 to 72.50%, respectively on artificial slope and from 44.53 to 95.33% and 48.36 to 73.15%, respectively on natural slope. Conservation values for phosphorus and nitrogen ranged from 40.83 to 88.89% and 59.78 to 82.22%, respectively on artificial slope and from 50.01 to 90.16% and 68.07 to 85.62%, respectively on natural slope. It was observed that Cynodon dactylon was the most efficient riparian species in conservation of soil, water and nutrients in surface runoff.

  10. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

    Science.gov (United States)

    Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

    2013-09-01

    The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  11. Impacts of hydroelectric dams on alluvial riparian plant communities in eastern Brazilian Amazonian

    Directory of Open Access Journals (Sweden)

    LEANDRO VALLE FERREIRA

    2013-09-01

    Full Text Available The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  12. Buffer layer annealing effects on the magnetization reversal process in Pd/Co/Pd systems

    International Nuclear Information System (INIS)

    Fassatoui, A.; Belhi, R.; Vogel, J.; Abdelmoula, K.

    2016-01-01

    We have investigated the effect of annealing the buffer layer on the magnetization reversal behavior in Pd/Co/Pd thin films using magneto-optical Kerr microscopy. It was found that annealing the buffer layer at 150 °C for 1 h decreases the coercivity and increases the saturation magnetization and the effective magnetic anisotropy constant. This study also shows that the annealing induces a change of the magnetization reversal from a mixed nucleation and domain wall propagation process to one dominated by domain wall propagation. This result demonstrates that the main effect of annealing the buffer layer is to decrease the domain wall pinning in the Co layer, favoring the domain wall propagation mode. - Highlights: • The buffer layer surface morphology changes upon annealing of the buffer layer. • The coercivity decreases while the saturation magnetization and the effective anisotropy increase with the annealing of the buffer layer. • The reversal process changes from a mixed nucleation and domain wall propagation process to one dominated by domain wall propagation when annealing the buffer layer.

  13. Importance of considering riparian vegetation requirements for the long-term efficiency of environmental flows in aquatic microhabitats

    Directory of Open Access Journals (Sweden)

    R. Rivaes

    2017-11-01

    Full Text Available Environmental flows remain biased toward the traditional biological group of fish species. Consequently, these flows ignore the inter-annual flow variability that rules species with longer lifecycles and therefore disregard the long-term perspective of the riverine ecosystem. We analyzed the importance of considering riparian requirements for the long-term efficiency of environmental flows. For that analysis, we modeled the riparian vegetation development for a decade facing different environmental flows in two case studies. Next, we assessed the corresponding fish habitat availability of three common fish species in each of the resulting riparian landscape scenarios. Modeling results demonstrated that the environmental flows disregarding riparian vegetation requirements promoted riparian degradation, particularly vegetation encroachment. Such circumstance altered the hydraulic characteristics of the river channel where flow depths and velocities underwent local changes of up to 10 cm and 40 cm s−1, respectively. Accordingly, after a decade of this flow regime, the available habitat area for the considered fish species experienced modifications of up to 110 % when compared to the natural habitat. In turn, environmental flows regarding riparian vegetation requirements were able to maintain riparian vegetation near natural standards, thereby preserving the hydraulic characteristics of the river channel and sustaining the fish habitat close to the natural condition. As a result, fish habitat availability never changed more than 17 % from the natural habitat.

  14. Recent land cover history and nutrient retention in riparian wetlands

    Science.gov (United States)

    Hogan, D.M.; Walbridge, M.R.

    2009-01-01

    Wetland ecosystems are profoundly affected by altered nutrient and sediment loads received from anthropogenic activity in their surrounding watersheds. Our objective was to compare a gradient of agricultural and urban land cover history during the period from 1949 to 1997, with plant and soil nutrient concentrations in, and sediment deposition to, riparian wetlands in a rapidly urbanizing landscape. We observed that recent agricultural land cover was associated with increases in Nitrogen (N) and Phosphorus (P) concentrations in a native wetland plant species. Conversely, recent urban land cover appeared to alter receiving wetland environmental conditions by increasing the relative availability of P versus N, as reflected in an invasive, but not a native, plant species. In addition, increases in surface soil Fe content suggests recent inputs of terrestrial sediments associated specifically with increasing urban land cover. The observed correlation between urban land cover and riparian wetland plant tissue and surface soil nutrient concentrations and sediment deposition, suggest that urbanization specifically enhances the suitability of riparian wetland habitats for the invasive species Japanese stiltgrass [Microstegium vimenium (Trinius) A. Camus]. ?? 2009 Springer Science+Business Media, LLC.

  15. COMBINATIONS OF BUFFER-STOCKS AND BUFFER-FUNDS FOR WOOL PRICE STABILISATION IN AUSTRALIA

    OpenAIRE

    Moir, Brian; Piggott, Roley R.

    1991-01-01

    In this paper a preliminary analysis is presented of a combined buffer-fund and buffer-stock as an alternative to a pure buffer-fund or a pure buffer stock for stabilising wool prices. The alternatives analysed are designed so that each provides the same prices to producers as did the Reserve Price Scheme over the period of analysis. Least-cost combinations of policy instruments are derived. The results show that there is considerable potential for cost savings to be made by combining buffer-...

  16. The influence of flood frequency, riparian vegetation and threshold on long-term river transport capacity

    Science.gov (United States)

    Croissant, Thomas; Lague, Dimitri; Davy, Philippe

    2016-04-01

    Climate fluctuations at geological timescales control the capacity of rivers to transport sediment with consequences on geochemical cycles, sedimentary basins dynamics and sedimentation/tectonics interactions. While the impact of differential friction generated by riparian vegetation has been studied for individual flood events, its impact on the long-term sediment transport capacity of rivers, modulated by the frequency of floods remains unknown. Here, we investigate this effect on a simplified river-floodplain configuration obeying observed hydraulic scaling laws. We numerically integrate the full-frequency magnitude distribution of discharge events and its impact on the transport capacity of bedload and suspended material for various level of vegetation-linked differential friction. We demonstrate that riparian vegetation by acting as a virtual confinement of the flow i) increases significantly the instantaneous transport capacity of the river independently of the transport mode and ii) increases the long term bedload transport rates as a function of discharge variability. Our results expose the dominance of flood frequency rather than riparian vegetation on the long term sediment transport capacity. Therefore, flood frequency has to be considered when evaluating long-term bedload transport capacity while floodplain vegetation is important only in high discharge variability regimes. By comparing the transport capacity of unconfined alluvial rivers and confined bedrock gorges, we demonstrate that the latter always presents the highest long term transport capacity at equivalent width and slope. The loss of confinement at the transition between bedrock and alluvial river must be compensated by a widening or a steepening of the alluvial channel to avoid infinite storage. Because steepening is never observed in natural system, we compute the alluvial widening factor value that varies between 3 to 11 times the width of the bedrock channel depending on riparian

  17. Developing management strategies for riparian areas.

    Science.gov (United States)

    D.E. Hibbs; S. Chan

    2001-01-01

    This talk outlines four principles that are critical to successful management of a riparian area. First, given problems both with defining historic conditions and with returning to them, attaining management goals based on restoration of ecological processes and functions will be far more successful. Second, the management goals for any stream reach must be placed in a...

  18. Distinctive channel geometry and riparian vegetation: A geomorphic classification for arid ephemeral streams

    Science.gov (United States)

    Sutfin, N.; Shaw, J. R.; Wohl, E. E.; Cooper, D.

    2012-12-01

    Interactions between hydrology, channel form, and riparian vegetation along arid ephemeral streams are not thoroughly understood and current stream classifications do not adequately represent variability in channel geometry and associated riparian communities. Relatively infrequent hydrologic disturbances in dryland environments are responsible for creation and maintenance of channel form that supports riparian communities. To investigate the influence of channel characteristics on riparian vegetation in the arid southwestern United States, we develop a geomorphic classification for arid ephemeral streams based on the degree of confinement and the composition of confining material that provide constraints on available moisture. Our conceptual model includes five stream types: 1) bedrock channels entirely confined by exposed bedrock and devoid of persistent alluvium; 2) bedrock with alluvium channels at least partially confined by bedrock but containing enough alluvium to create bedforms that persist through time; 3) incised alluvium channels bound only by unconsolidated alluvial material into which they are incised; 4) braided washes that exhibit multi-thread, braided characteristics regardless of the composition of confining material; and 5) piedmont headwater 0-2nd order streams (Strahler) confined only by unconsolidated alluvium and which initiate as secondary channels on piedmont surfaces. Eighty-six study reaches representing the five stream types were surveyed on the U.S. Army Yuma Proving Ground in the Sonoran Desert of southwestern Arizona. Non-parametric multivariate analysis of variance (PERMANOVA) indicates significant differences between the five stream types with regards to channel geometry (i.e., stream gradient, width-to-depth ratio, the ratio between valley width and channel width (Wv/Wc), shear stress, and unit stream power) and riparian vegetation (i.e., presence and canopy coverage by species, canopy stratum, and life form). Discriminant analysis

  19. Aquatic grazers reduce the establishment and growth of riparian plants along an environmental gradient

    NARCIS (Netherlands)

    Veen, G.F.; Sarneel, J.M.; Ravensbergen, Lone; Huig, N.; van Paassen, José; Rip, W.; Bakker, E.S.

    2013-01-01

    Summary The establishment of riparian plants is determined by abiotic conditions and grazing, although it is usually presumed that the former are most important. We tested the impact of aquatic grazers on the survival and growth of establishing riparian plants and whether the impact of grazing

  20. Temperature buffer test. Installation of buffer, heaters and instruments in the deposition hole

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik; Sanden, Torbjoern; Aakesson, Mattias [Clay Technology AB, Lund (Sweden); Barcena, Ignacio; Garcia-Sineriz, Jose Luis [Aitemin, Madrid (Spain)

    2010-12-15

    During 2003 the Temperature Buffer Test was installed in Aespoe Hard Rock Laboratory. Temperature, water pressure, relative humidity, total pressure and displacements etc. are measured in numerous points in the test. Most of the cables from the transducers are led in the deposition hole through slots in the rock surface of the deposition hole in watertight tubes to the data collection system in a container placed in the tunnel close to the deposition hole. This report describes the work with the installations of the buffer, heaters, and instruments and yields a description of the final location of all instruments. The report also contains a description of the materials that were installed and the densities yielded after placement.

  1. Temperature buffer test. Installation of buffer, heaters and instruments in the deposition hole

    International Nuclear Information System (INIS)

    Johannesson, Lars-Erik; Sanden, Torbjoern; Aakesson, Mattias; Barcena, Ignacio; Garcia-Sineriz, Jose Luis

    2010-12-01

    During 2003 the Temperature Buffer Test was installed in Aespoe Hard Rock Laboratory. Temperature, water pressure, relative humidity, total pressure and displacements etc. are measured in numerous points in the test. Most of the cables from the transducers are led in the deposition hole through slots in the rock surface of the deposition hole in watertight tubes to the data collection system in a container placed in the tunnel close to the deposition hole. This report describes the work with the installations of the buffer, heaters, and instruments and yields a description of the final location of all instruments. The report also contains a description of the materials that were installed and the densities yielded after placement

  2. A readout buffer prototype for ATLAS high-level triggers

    CERN Document Server

    Calvet, D; Huet, M; Le Dû, P; Mandjavidze, I D; Mur, M

    2001-01-01

    Readout buffers are critical components in the dataflow chain of the ATLAS trigger/data-acquisition system. At up to 75 kHz, after each Level-1 trigger accept signal, these devices receive and store digitized data from groups of front-end electronic channels. Several readout buffers are grouped to form a readout buffer complex that acts as a data server for the high-level trigger selection algorithms and for the final data-collection system. This paper describes a functional prototype of a readout buffer based on a custom-made PCI mezzanine card that is designed to accept input data at up to 160 MB /s, to store up to 8 MB of data, and to distribute data chunks at the desired request rate. We describe the hardware of the card that is based on an Intel 1960 processor and complex programmable logic devices. We present the integration of several of these cards in a readout buffer complex. We measure various performance figures and discuss to which extent these can fulfil ATLAS needs. (5 refs).

  3. Organellar Calcium Buffers

    Science.gov (United States)

    Prins, Daniel; Michalak, Marek

    2011-01-01

    Ca2+ is an important intracellular messenger affecting many diverse processes. In eukaryotic cells, Ca2+ storage is achieved within specific intracellular organelles, especially the endoplasmic/sarcoplasmic reticulum, in which Ca2+ is buffered by specific proteins known as Ca2+ buffers. Ca2+ buffers are a diverse group of proteins, varying in their affinities and capacities for Ca2+, but they typically also carry out other functions within the cell. The wide range of organelles containing Ca2+ and the evidence supporting cross-talk between these organelles suggest the existence of a dynamic network of organellar Ca2+ signaling, mediated by a variety of organellar Ca2+ buffers. PMID:21421925

  4. BENTO buffer development program in Finland - Key issues

    International Nuclear Information System (INIS)

    Autio, J.; Korkiala-Tanttu, L.; Vaehaenen, M.; Koskinen, K.; Korkeakoski, P.; Haapala, K.

    2010-01-01

    Document available in extended abstract form only. Posiva launched a programme, BENTO, to develop technology of using bentonite in spent nuclear fuel repositories. The main purpose of the BENTO programme is to produce buffer designs and verify that they fulfil the requirements, especially safety requirements. To achieve this objective, resources and the level of expertise and know-how has to be increased. There are several uncertainties related to the functioning of the buffer components at present. An issue is defined as being significant if there is sufficient uncertainty that the buffer system might not fulfil the requirements because of the issue. These significant issues need to be resolved in order to develop a proper design and to verify the fulfilment of the requirements. The list of significant issues may change with time. Therefore it is crucial to develop adequate expertise, know-how and laboratory facilities to manage the changes. Moreover, there is confidence that by solving the open issues a defendable construction license application can be submitted in 2012. The basic nature of the programme is a combination of material and process research with the design and manufacturing of buffer components to produce feasible buffer design with proven long-term functional properties. The development work carried out under BENTO-programme has been initially divided into four different projects. During the course of work the number of projects and their content can be adjusted. The four BENTO projects are: 1. Manufacturing (MANU); 2. Design (DESI); 3. Modelling (MODE); 4. Material and Process Research (MARE). BENTO programme aims at producing feasible buffer designs which fulfil the requirements specified in Posiva's requirement management system. The designs are produced in DESI-project by following the design development scheme which starts from specification of design basis and ends in documented detailed designs and therefore DESIgn is specified as one

  5. Viscosity changes of riparian water controls diurnal fluctuations of stream-flow and DOC concentration

    Science.gov (United States)

    Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

    2015-04-01

    Diurnal fluctuations in stream-flow are commonly explained as being triggered by the daily evapotranspiration cycle in the riparian zone, leading to stream flow minima in the afternoon. While this trigger effect must necessarily be constrained by the extent of the growing season of vegetation, we here show evidence of daily stream flow maxima in the afternoon in a small headwater stream during the dormant season. We hypothesize that the afternoon maxima in stream flow are induced by viscosity changes of riparian water that is caused by diurnal temperature variations of the near surface groundwater in the riparian zone. The patterns were observed in the Weierbach headwater catchment in Luxembourg. The catchment is covering an area of 0.45 km2, is entirely covered by forest and is dominated by a schistous substratum. DOC concentration at the outlet of the catchment was measured with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH) with a high frequency of 15 minutes over several months. Discharge was measured with an ISCO 4120 Flow Logger. During the growing season, stream flow shows a frequently observed diurnal pattern with discharge minima in the afternoon. During the dormant season, a long dry period with daily air temperature amplitudes of around 10 ° C occurred in March and April 2014, with discharge maxima in the afternoon. The daily air temperature amplitude led to diurnal variations in the water temperature of the upper 10 cm of the riparian zone. Higher riparian water temperatures cause a decrease in water viscosity and according to the Hagen-Poiseuille equation, the volumetric flow rate is inversely proportional to viscosity. Based on the Hagen-Poiseuille equation and the viscosity changes of water, we calculated higher flow rates of near surface groundwater through the riparian zone into the stream in the afternoon which explains the stream flow maxima in the afternoon. With the start of the growing season, the viscosity

  6. Transport and retention of pollutants from different production systems

    Energy Technology Data Exchange (ETDEWEB)

    Mander, Ue. (Dept. of Geography, Univ. of Tartu (Estonia)); Shirmohammadi, A. (Fischell Dept. of Bioengineering, Univ. of Maryland, MD (United States))

    2008-07-01

    Transport and retentions of agricultural pollutants both at farm level and catchment scale are key challenges faced by researchers, environmental managers, and regulatory agencies. Researchers have responded to this challenge by either monitoring or modelling strategies. Models, both empirical and theoretical, have been developed and used at different scales trying to evaluate the dynamics of the pollutants as they move from upland agricultural areas to water bodies. Monitoring studies at different scales (plot, field, catchment) have tried to represent the natural system and provide data-base for calibrating and testing mathematical models. Scientists have also used both modelling and monitoring strategies to evaluate the impact of different management practices such as contour cropping, vegetated buffer strips, riparian zones, and constructed wetlands on reduction of pollutant loads to water bodies. Manuscripts presented in this special issue provide results of both modelling and monitoring at different scales as they relate to transport and retention of nutrients in different landscapes. For example, it covers application of SWAT model in Finland to meet the environmental goals of European Water Framework Directive, and application of the same model in the US to meet the Total Maximum Daily Load mandated by US's 1972 Clean Water Act. Also covered are results on nutrient and sediment reduction due to different management practices including vegetated buffer strips, riparian zones, and constructed wetlands. Overall results of monitoring indicate effectiveness of such practices in attenuating sediment and nutrients, thus reducing their entry into the water bodies. (orig.)

  7. Impact of Burst Buffer Architectures on Application Portability

    Energy Technology Data Exchange (ETDEWEB)

    Harms, Kevin [Argonne National Lab. (ANL), Argonne, IL (United States); Oral, H. Sarp [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Science; Atchley, Scott [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Science; Vazhkudai, Sudharshan S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Science

    2016-09-30

    The Oak Ridge and Argonne Leadership Computing Facilities are both receiving new systems under the Collaboration of Oak Ridge, Argonne, and Livermore (CORAL) program. Because they are both part of the INCITE program, applications need to be portable between these two facilities. However, the Summit and Aurora systems will be vastly different architectures, including their I/O subsystems. While both systems will have POSIX-compliant parallel file systems, their Burst Buffer technologies will be different. This difference may pose challenges to application portability between facilities. Application developers need to pay attention to specific burst buffer implementations to maximize code portability.

  8. Indirect effects of biocontrol of an invasive riparian plant (Tamarix) alters habitat and reduces herpetofauna abundance

    Science.gov (United States)

    Bateman, H.L.; Merritt, D.M.; Glenn, E.P.; Nagler, P.L.

    2014-01-01

    The biological control agent (tamarisk leaf beetle, Diorhabda spp.) is actively being used to defoliate exotic saltcedar or tamarisk (Tamarix spp.) in riparian ecosystems in western USA. The Virgin River in Arizona and Nevada is a system where tamarisk leaf beetle populations are spreading. Saltcedar biocontrol, like other control methods, has the potential to affect non-target species. Because amphibians and reptiles respond to vegetation changes in habitat and forage in areas where beetles are active, herpetofauna are model taxa to investigate potential impacts of biocontrol defoliation. Our objectives related herpetofauna abundance to vegetation cover and indices (normalized difference vegetation index, NDVI; enhanced vegetation index, EVI) and timing of biocontrol defoliation. We captured herpetofauna and ground-dwelling arthropods in trap arrays and measured vegetation using remotely sensed images and on-the-ground measurements at 16–21 sites 2 years before (2009–2010) and 2 years following (2011–2012) biocontrol defoliation. Following defoliation, riparian stands (including stands mixed with native and exotic trees and stands of monotypic exotic saltcedar) had significantly lower NDVI and EVI values and fewer captures of marked lizards. Total captures of herpetofauna (toads, lizards, and snakes) were related to higher vegetation cover and sites with a lower proportion of saltcedar. Our results suggest that effects of biocontrol defoliation are likely to be site-specific and depend upon the proportion of native riparian trees established prior to biocontrol introduction and defoliation. The mechanisms by which habitat structure, microclimate, and ultimately vertebrate species are affected by exotic plant biocontrol riparian areas should be a focus of natural-resource managers.

  9. Buffer protection in the installation phase

    Energy Technology Data Exchange (ETDEWEB)

    Wimelius, Hans (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)); Pusch, Roland (Geodevelopment International AB, Lund (Sweden))

    2008-12-15

    The research and development of the design and construction of the SKB's repository for final disposal of spent reactor fuel is conducted along several paths ('lines'). Issues concerning the bedrock are dealt with in the 'rock line' and those related to buffer and backfill in deposition holes and tunnels are considered in the 'buffer line' and 'backfill line', respectively. These lines also deal with sub-activities that are coupled to several other lines. One of them includes development of techniques for protecting buffer blocks from moisture and water in the installation phase. Techniques and methods for placement and removal of the 'buffer protection sheet' are dealt with in the 'buffer line'. The removal is, however, considered as being part of the backfilling sequence. Since the performance of the sheet is of fundamental importance to the placement and function of the buffer it deserves particular attention. Thus, the removal of the rubber sheet that serves to protect the buffer blocks in the installation phase may be difficult and can cause significant problems that may require retrieval of already placed canister, buffer and backfill. These matters are in focus in the present report. Arrangements for protecting already placed buffer blocks from moist air and water have been tested in earlier large-scale experiments, i.e. the Prototype Repository project at Aespoe but the experience from them has called for more effective protection of the clay blocks as described in the present report. Focus is on the construction of foundation components at the bottom of the deposition holes required for establishing a tight seal between rock and buffer blocks, and on the protection sheet and arrangements for limiting water pressure on it. Special attention is paid to the drainage of the space between rock and protection sheet that is necessary for avoiding failure of the sheet and to systems for achieving

  10. Evaluation on elution feature of bentonite buffer materials

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Hirohisa; Kanno, Takeshi; Matsumoto, Kazuhiro

    1997-09-01

    In order to evaluate long term physical stability of artificial barrier in land disposal of high level radioactive wastes, it is necessary to know quantitatively elution behavior of buffering materials from disposal road (or cavity) to circumferential rock crack. When elution of the buffer material occurs on large scale, amount of bentonite in the disposal road (or cavity) reduces and reduction of various functions expected to the buffer materials is presumed. According to specification examples of road transverse arrangement and disposal vertical arrangement systems, evaluation on elution amount of the buffer materials at disposal environment was conducted. Opening width of rock crack in the disposal environment was supposed to be 0.5 mm. As a result, obtained mass elution ratios of the buffer materials due to extrusion phenomenon were 0.04 to 0.2% after 10,000 year and 2 to 12% after 1,000,000 years. (G.K.)

  11. Effects of buffer thickness on ATW blanket performance

    International Nuclear Information System (INIS)

    Yang, W. S.; Mercatali, L.; Taiwo, T. A.; Hill, R. N.

    2001-01-01

    This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy ( and lt; 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level

  12. Effects of Buffer Thickness on ATW Blanket Performance

    International Nuclear Information System (INIS)

    Yang, W.S.; Mercatali, L.; Taiwo, T.A.; Hill, R.N.

    2002-01-01

    This paper presents preliminary results of target and buffer design studies for liquid metal cooled accelerator transmutation of waste (ATW) systems, aimed at maximizing the source importance while simultaneously reducing the irradiation damage to fuel. Using 840 MWt liquid metal cooled ATW designs, the effects of buffer thickness on the blanket performance have been studied. Varying the buffer thickness for a given blanket configuration, system performance parameters have been estimated by a series of calculations using the MCNPX and REBUS-3 codes. The effects of source importance variation are studied by investigating the low-energy (< 20 MeV) neutron source distribution and the equilibrium cycle blanket performance parameters such as fuel inventory, discharge burnup, burnup reactivity loss, and peak fast fluence. For investigating irradiation damage to fuel, the displacements per atom (dpa), hydrogen production, and helium production rates are evaluated at the buffer and blanket interface where the peak fast fluence occurs. Results for the liquid-metal-cooled designs show that the damage rates and the source importance increase monotonically as the buffer thickness decreases. Based on a compromise between the competing objectives of increasing the source importance and reducing the damage rates, a buffer thickness of around 20 cm appears to be reasonable. Investigation of the impact of the proton beam energy on the target and buffer design shows that for a given blanket power level, a lower beam energy (0.6 GeV versus 1 GeV) results in a higher irradiation damage to the beam window. This trend occurs because of the increase in the beam intensity required to maintain the power level. (authors)

  13. Methods for improved growth of group III nitride buffer layers

    Science.gov (United States)

    Melnik, Yurity; Chen, Lu; Kojiri, Hidehiro

    2014-07-15

    Methods are disclosed for growing high crystal quality group III-nitride epitaxial layers with advanced multiple buffer layer techniques. In an embodiment, a method includes forming group III-nitride buffer layers that contain aluminum on suitable substrate in a processing chamber of a hydride vapor phase epitaxy processing system. A hydrogen halide or halogen gas is flowing into the growth zone during deposition of buffer layers to suppress homogeneous particle formation. Some combinations of low temperature buffers that contain aluminum (e.g., AlN, AlGaN) and high temperature buffers that contain aluminum (e.g., AlN, AlGaN) may be used to improve crystal quality and morphology of subsequently grown group III-nitride epitaxial layers. The buffer may be deposited on the substrate, or on the surface of another buffer. The additional buffer layers may be added as interlayers in group III-nitride layers (e.g., GaN, AlGaN, AlN).

  14. Inter-species competition-facilitation in stochastic riparian vegetation dynamics.

    Science.gov (United States)

    Tealdi, Stefano; Camporeale, Carlo; Ridolfi, Luca

    2013-02-07

    Riparian vegetation is a highly dynamic community that lives on river banks and which depends to a great extent on the fluvial hydrology. The stochasticity of the discharge and erosion/deposition processes in fact play a key role in determining the distribution of vegetation along a riparian transect. These abiotic processes interact with biotic competition/facilitation mechanisms, such as plant competition for light, water, and nutrients. In this work, we focus on the dynamics of plants characterized by three components: (1) stochastic forcing due to river discharges, (2) competition for resources, and (3) inter-species facilitation due to the interplay between vegetation and fluid dynamics processes. A minimalist stochastic bio-hydrological model is proposed for the dynamics of the biomass of two vegetation species: one species is assumed dominant and slow-growing, the other is subdominant, but fast-growing. The stochastic model is solved analytically and the probability density function of the plant biomasses is obtained as a function of both the hydrologic and biologic parameters. The impact of the competition/facilitation processes on the distribution of vegetation species along the riparian transect is investigated and remarkable effects are observed. Finally, a good qualitative agreement is found between the model results and field data. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Responses of riparian reptile communities to damming and urbanization

    Science.gov (United States)

    Hunt, Stephanie D.; Guzy, Jacquelyn C.; Price, Steven J.; Halstead, Brian J.; Eskew, Evan A.; Dorcas, Michael E.

    2013-01-01

    Various anthropogenic pressures, including habitat loss, threaten reptile populations worldwide. Riparian zones are critical habitat for many reptile species, but these habitats are also frequently modified by anthropogenic activities. Our study investigated the effects of two riparian habitat modifications-damming and urbanization-on overall and species-specific reptile occupancy patterns. We used time-constrained search techniques to compile encounter histories for 28 reptile species at 21 different sites along the Broad and Pacolet Rivers of South Carolina. Using a hierarchical Bayesian analysis, we modeled reptile occupancy responses to a site's distance upstream from dam, distance downstream from dam, and percent urban land use. The mean occupancy response by the reptile community indicated that reptile occupancy and species richness were maximized when sites were farther upstream from dams. Species-specific occupancy estimates showed a similar trend of lower occupancy immediately upstream from dams. Although the mean occupancy response of the reptile community was positively related to distance downstream from dams, the occupancy response to distance downstream varied among species. Percent urban land use had little effect on the occupancy response of the reptile community or individual species. Our results indicate that the conditions of impoundments and subsequent degradation of the riparian zones upstream from dams may not provide suitable habitat for a number of reptile species.

  16. Wildlife Response to Riparian Restoration on the Sacramento River

    Directory of Open Access Journals (Sweden)

    Gregory H Golet

    2008-06-01

    Full Text Available Studies that assess the success of riparian restoration projects seldom focus on wildlife. More generally, vegetation characteristics are studied, with the assumption that animal populations will recover once adequate habitats are established. On the Sacramento River, millions of dollars have been spent on habitat restoration, yet few studies of wildlife response have been published. Here we present the major findings of a suite of studies that assessed responses of four taxonomic groups (insects, birds, bats, and rodents. Study designs fell primarily into two broad categories: comparisons of restoration sites of different ages, and comparisons of restoration sites with agricultural and remnant riparian sites. Older restoration sites showed increased abundances of many species of landbirds and bats relative to younger sites, and the same trend was observed for the Valley elderberry longhorn beetle (Desmocerus californicus dimorphus, a federally threatened species. Species richness of landbirds and ground-dwelling beetles appeared to increase as restoration sites matured. Young restoration sites provided benefits to species that utilize early successional riparian habitats, and after about 10 years, the sites appeared to provide many of the complex structural habitat elements that are characteristic of remnant forest patches. Eleven-year old sites were occupied by both cavity-nesting birds and special-status crevice-roosting bats. Restored sites also supported a wide diversity of bee species, and had richness similar to remnant sites. Remnant sites had species compositions of beetles and rodents more similar to older sites than to younger sites. Because study durations were short for all but landbirds, results should be viewed as preliminary. Nonetheless, in aggregate, they provide convincing evidence that restoration along the Sacramento River has been successful in restoring riparian habitats for a broad suite of faunal species. Not only did

  17. Monitoring riparian-vegetation composition and cover along the Colorado River downstream of Glen Canyon Dam, Arizona

    Science.gov (United States)

    Palmquist, Emily C.; Ralston, Barbara E.; Sarr, Daniel A.; Johnson, Taylor C.

    2018-06-05

    Vegetation in the riparian zone (the area immediately adjacent to streams, such as stream banks) along the Colorado River downstream of Glen Canyon Dam, Arizona, supports many ecosystem and societal functions. In both Glen Canyon and Grand Canyon, this ecosystem has changed over time in response to flow alterations, invasive species, and recreational use. Riparian-vegetation cover and composition are likely to continue to change as these pressures persist and new ones emerge. Because this system is a valuable resource that is known to change in response to flow regime and other disturbances, a long-term monitoring protocol has been designed with three primary objectives:Annually measure and summarize the status (composition and cover) of native and non-native vascular-plant species within the riparian zone of the Colorado River between Glen Canyon Dam and Lake Mead.At 5-year intervals, assess change in vegetation composition and cover in the riparian zone, as related to geomorphic setting and dam operations, particularly flow regime.Collect data in a manner that can be used by multiple stakeholders, particularly the basinwide monitoring program overseen by the National Park Service’s Northern Colorado Plateau Network Inventory and Monitoring program.A protocol for the long-term monitoring of riparian vegetation is described in detail and standard operating procedures are included herein for all tasks. Visual estimates of foliar and ground covers are collected in conjunction with environmental measurements to assess correlations of foliar cover with abiotic and flow variables. Sample quadrats are stratified by frequency of inundation, geomorphic feature, and by river segment to account for differences in vegetation type. Photographs of sites are also taken to illustrate qualitative characteristics of the site at the time of sampling. Procedures for field preparation, generating random samples, data collection, data management, collecting and managing unknown

  18. Swelling characteristics of buffer material

    International Nuclear Information System (INIS)

    Suzuki, Hideaki; Fujita, Tomoo

    1999-12-01

    After emplacement of the engineered barrier system (EBS), it is expected that the near-field environment will be impacted by phenomena such as heat dissipation by conduction and other heat transfer mechanism, infiltration of groundwater from the surrounding rock into the EBS, generation of swelling pressure in the buffer due to water infiltration and the stress imposed by the overburden pressure. These phenomena are not all independent, but can be strongly influenced by, and coupled with, each other. Evaluating these coupled thermo-hydro-mechanical phenomena is important in order to clarify the initial transient behavior of the engineered barrier system within the near-field. This report describes the results on measurement of swelling amount and stress at boundary built up under restraint condition with water uptake. The following results are identified. (1) The swelling stress of buffer material at saturated condition tends to be independent of effects of pore water pressure and synthetic sea water, and to decrease with increasing temperature. The swelling stress can be explained by the effective dry density. (2) The strain due to swelling estimated from the results of the swelling amount of buffer material is proportional to swelling stress. (3) The swelling stress and strain under unsaturated condition increase with water uptake. (author)

  19. Effects of local land-use on riparian vegetation, water quality, and the functional organization of macroinvertebrate assemblages.

    Science.gov (United States)

    Fierro, Pablo; Bertrán, Carlos; Tapia, Jaime; Hauenstein, Enrique; Peña-Cortés, Fernando; Vergara, Carolina; Cerna, Cindy; Vargas-Chacoff, Luis

    2017-12-31

    Land-use change is a principal factor affecting riparian vegetation and river biodiversity. In Chile, land-use change has drastically intensified over the last decade, with native forests converted to exotic forest plantations and agricultural land. However, the effects thereof on aquatic ecosystems are not well understood. Closing this knowledge gap first requires understanding how human perturbations affect riparian and stream biota. Identified biological indicators could then be applied to determine the health of fluvial ecosystems. Therefore, this study investigated the effects of land-use change on the health of riparian and aquatic ecosystems by assessing riparian vegetation, water quality, benthic macroinvertebrate assemblages, and functional feeding groups. Twenty-one sites in catchment areas with different land-uses (i.e. pristine forests, native forests, exotic forest plantations, and agricultural land) were selected and sampled during the 2010 to 2012 dry seasons. Riparian vegetation quality was highest in pristine forests. Per the modified Macroinvertebrate Family Biotic Index for Chilean species, the best conditions existed in native forests and the worst in agricultural catchments. Water quality and macroinvertebrate assemblages significantly varied across land-use areas, with forest plantations and agricultural land having high nutrient concentrations, conductivity, suspended solids, and apparent color. Macroinvertebrate assemblage diversity was lowest for agricultural and exotic forest plantation catchments, with notable non-insect representation. Collector-gatherers were the most abundant functional feeding group, suggesting importance independent of land-use. Land-use areas showed no significant differences in functional feeding groups. In conclusion, anthropogenic land-use changes were detectable through riparian quality, water quality, and macroinvertebrate assemblages, but not through functional feeding groups. These data, particularly the

  20. Effects of climate-induced increases in summer drought on riparian plant species : a meta-analysis

    NARCIS (Netherlands)

    Garssen, Annemarie G.; Verhoeven, Jos T. A.; Soons, Merel B.

    Frequency and duration of summer droughts are predicted to increase in the near future in many parts of the world, with considerable anticipated effects on riparian plant community composition and species richness. Riparian plant communities along lowland streams are characterised by high species

  1. Stream channel designs for riparian and wet meadow rangelands in the southwestern United States

    Science.gov (United States)

    Roy Jemison; Daniel G. Neary

    2000-01-01

    Inappropriate land uses have degraded wetland and riparian ecosystems throughout the Southwestern United States. In 1996, the Cibola National Forest in New Mexico implemented a channel relocation project, as part of a road improvement project, to determine the feasibility of restoring wet meadow and riparian ecosystems degraded by inappropriately located roads and...

  2. Avian nest box selection and nest success in burned and unburned southwestern riparian forests

    Science.gov (United States)

    D. Max Smith; Jeffrey F. Kelly; Deborah M. Finch

    2007-01-01

    Riparian forest communities in the southwestern United States were historically structured by a disturbance regime of annual flooding. In recent decades, however, frequency of flooding has decreased and frequency of wildfires has increased. Riparian forests provide important breeding habitat for a large variety of bird species, and the effects of this altered...

  3. VT River Restoration Data in Lamoille County

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) Documented river and riparian buffer restoration projects in Lamoille County, Vermont. Restoration includes buffer plantings (trees and shrubs),...

  4. Multicriteria analysis to evaluate the energetic reuse of riparian vegetation

    International Nuclear Information System (INIS)

    Recchia, Lucia; Cini, Enrico; Corsi, Stefano

    2010-01-01

    The management of riparian vegetation which includes cutting operations of grass, reeds, bushes and trees, is very important to reduce hydrogeologic risk. In Tuscany, riparian biomass and residues are mainly left shredded along courses or disposed in landfills as special wastes: actually different laws prohibit that tree trunks are abandoned in areas naturally affected by flooding, because they can be moved contributing to increase the water level and to maximize the hydraulic risk of some other nearby areas. In some cases, it is also possible to store the logs in specified sites from where they can be taken and used as a fuel in fireplaces or domestic heating plants. This work studies the possibility of the reuse of riparian vegetation as biomass for energy production and evaluates benefits and drawbacks from the economical, environmental and managerial points of view. Particularly, a specific methodology has been developed for two hydrological districts of Tuscany, with different typologies and densities of vegetation. First, an estimation of biomass distribution on the land and an evaluation of annual wood availability have been carried out; then, different chains concerning harvesting operation, biomass transport, storage conditions and final utilisation, have been defined and compared by a specific multicriteria analysis (MCA); finally, for the most suitable bio-energy chains the Life Cycle Assessment (LCA) has been implemented. Results of the LCA have also permitted to validate some environmental indicators used in the MCA, as mechanisation level of yards, energy efficiency of plants or transport distances. The decision making tool developed allows to compare costs and environmental benefits of the energy use of riparian vegetation, supporting local authorities involved in energy planning: in this way it is possible to confront different alternatives to match the energy demand and meet the energy saving and sustainability issues at the lowest cost for the

  5. Multicriteria analysis to evaluate the energetic reuse of riparian vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Recchia, Lucia; Cini, Enrico [Dipartimento di Ingegneria Agraria e Forestale, Universita di Firenze, Piazzale delle Cascine 15, 50144 Firenze (Italy); Corsi, Stefano [Consorzio di Bonifica per la difesa del suolo e la tutela dell' ambiente della Toscana Centrale, via Verdi 16, 50122 Firenze (Italy)

    2010-01-15

    The management of riparian vegetation which includes cutting operations of grass, reeds, bushes and trees, is very important to reduce hydrogeologic risk. In Tuscany, riparian biomass and residues are mainly left shredded along courses or disposed in landfills as special wastes: actually different laws prohibit that tree trunks are abandoned in areas naturally affected by flooding, because they can be moved contributing to increase the water level and to maximize the hydraulic risk of some other nearby areas. In some cases, it is also possible to store the logs in specified sites from where they can be taken and used as a fuel in fireplaces or domestic heating plants. This work studies the possibility of the reuse of riparian vegetation as biomass for energy production and evaluates benefits and drawbacks from the economical, environmental and managerial points of view. Particularly, a specific methodology has been developed for two hydrological districts of Tuscany, with different typologies and densities of vegetation. First, an estimation of biomass distribution on the land and an evaluation of annual wood availability have been carried out; then, different chains concerning harvesting operation, biomass transport, storage conditions and final utilisation, have been defined and compared by a specific multicriteria analysis (MCA); finally, for the most suitable bio-energy chains the Life Cycle Assessment (LCA) has been implemented. Results of the LCA have also permitted to validate some environmental indicators used in the MCA, as mechanisation level of yards, energy efficiency of plants or transport distances. The decision making tool developed allows to compare costs and environmental benefits of the energy use of riparian vegetation, supporting local authorities involved in energy planning: in this way it is possible to confront different alternatives to match the energy demand and meet the energy saving and sustainability issues at the lowest cost for the

  6. Deforestation and benthic indicators: how much vegetation cover is needed to sustain healthy Andean streams?

    Science.gov (United States)

    Iñiguez-Armijos, Carlos; Leiva, Adrián; Frede, Hans-Georg; Hampel, Henrietta; Breuer, Lutz

    2014-01-01

    Deforestation in the tropical Andes is affecting ecological conditions of streams, and determination of how much forest should be retained is a pressing task for conservation, restoration and management strategies. We calculated and analyzed eight benthic metrics (structural, compositional and water quality indices) and a physical-chemical composite index with gradients of vegetation cover to assess the effects of deforestation on macroinvertebrate communities and water quality of 23 streams in southern Ecuadorian Andes. Using a geographical information system (GIS), we quantified vegetation cover at three spatial scales: the entire catchment, the riparian buffer of 30 m width extending the entire stream length, and the local scale defined for a stream reach of 100 m in length and similar buffer width. Macroinvertebrate and water quality metrics had the strongest relationships with vegetation cover at catchment and riparian scales, while vegetation cover did not show any association with the macroinvertebrate metrics at local scale. At catchment scale, the water quality metrics indicate that ecological condition of Andean streams is good when vegetation cover is over 70%. Further, macroinvertebrate community assemblages were more diverse and related in catchments largely covered by native vegetation (>70%). Our results suggest that retaining an important quantity of native vegetation cover within the catchments and a linkage between headwater and riparian forests help to maintain and improve stream biodiversity and water quality in Andean streams affected by deforestation. This research proposes that a strong regulation focused to the management of riparian buffers can be successful when decision making is addressed to conservation/restoration of Andean catchments.

  7. Estimating riparian and agricultural evapotranspiration by reference crop evapotranspiration and MODIS Enhanced Vegetation Index

    Science.gov (United States)

    Nagler, Pamela L.; Glenn, Edward P.; Nguyen, Uyen; Scott, Russell; Doody, Tania

    2013-01-01

    Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa) based on the Enhanced Vegetation Index (EVI) from the Moderate Resolution Imaging Spectrometer (MODIS) sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo). The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 − e−bEVI) − c], where the term (1 − e−bEVI) is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73). It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89) difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

  8. Estimating Riparian and Agricultural Actual Evapotranspiration by Reference Evapotranspiration and MODIS Enhanced Vegetation Index

    Directory of Open Access Journals (Sweden)

    Russell L. Scott

    2013-08-01

    Full Text Available Dryland river basins frequently support both irrigated agriculture and riparian vegetation and remote sensing methods are needed to monitor water use by both crops and natural vegetation in irrigation districts. We developed an algorithm for estimating actual evapotranspiration (ETa based on the Enhanced Vegetation Index (EVI from the Moderate Resolution Imaging Spectrometer (MODIS sensor on the EOS-1 Terra satellite and locally-derived measurements of reference crop ET (ETo. The algorithm was calibrated with five years of ETa data from three eddy covariance flux towers set in riparian plant associations on the upper San Pedro River, Arizona, supplemented with ETa data for alfalfa and cotton from the literature. The algorithm was based on an equation of the form ETa = ETo [a(1 − e−bEVI − c], where the term (1 − e−bEVI is derived from the Beer-Lambert Law to express light absorption by a canopy, with EVI replacing leaf area index as an estimate of the density of light-absorbing units. The resulting algorithm capably predicted ETa across riparian plants and crops (r2 = 0.73. It was then tested against water balance data for five irrigation districts and flux tower data for two riparian zones for which season-long or multi-year ETa data were available. Predictions were within 10% of measured results in each case, with a non-significant (P = 0.89 difference between mean measured and modeled ETa of 5.4% over all validation sites. Validation and calibration data sets were combined to present a final predictive equation for application across crops and riparian plant associations for monitoring individual irrigation districts or for conducting global water use assessments of mixed agricultural and riparian biomes.

  9. Human impacts on riparian ecosystems of the Middle Rio Grande Valley during historic times

    Science.gov (United States)

    Frank E. Wozniak

    1996-01-01

    The development of irrigation agriculture in historic times has profoundly impacted riparian ecosystems in the Middle Rio Grande Valley of New Mexico. A vital relationship has existed between water resources and settlement in the semi-arid Southwest since prehistoric times. Levels of technology have influenced human generated changes in the riparian ecosystems of the...

  10. Riparian vegetation in the alpine connectome: Terrestrial-aquatic and terrestrial-terrestrial interactions.

    Science.gov (United States)

    Zaharescu, Dragos G; Palanca-Soler, Antonio; Hooda, Peter S; Tanase, Catalin; Burghelea, Carmen I; Lester, Richard N

    2017-12-01

    Alpine regions are under increased attention worldwide for their critical role in early biogeochemical cycles, their high sensitivity to environmental change, and as repositories of natural resources of high quality. Their riparian ecosystems, at the interface between aquatic and terrestrial environments, play important geochemical functions in the watershed and are biodiversity hotspots, despite a harsh climate and topographic setting. With climate change rapidly affecting the alpine biome, we still lack a comprehensive understanding of the extent of interactions between riparian surface, lake and catchment environments. A total of 189 glacial - origin lakes were surveyed in the Central Pyrenees to test how key elements of the lake and terrestrial environments interact at different scales to shape riparian plant composition. Secondly, we evaluated how underlying ecotope features drive the formation of natural communities potentially sensitive to environmental change and assessed their habitat distribution. At the macroscale, vegetation composition responded to pan-climatic gradients altitude and latitude, which captured in a narrow geographic area the transition between large European climatic zones. Hydrodynamics was the main catchment-scale factor connecting riparian vegetation with major water fluxes, followed by topography and geomorphology. Lake sediment Mg and Pb, and water Mn and Fe contents reflected local influences from mafic bedrock and soil water saturation. Community analysis identified four keystone ecosystems: (i) damp ecotone, (ii) snow bed-silicate bedrock, (iii) wet heath, and (iv) calcareous substrate. These communities and their connections with ecotope elements could be at risk from a number of environmental change factors including warmer seasons, snow line and lowland species advancement, increased nutrient/metal input and water level fluctuations. The results imply important natural terrestrial-aquatic linkages in the riparian environment

  11. Identifying spatially integrated floodplains/riparian areas and wetlands

    Science.gov (United States)

    Floodplain delineation may play an important role in managing wetlands and riparian areas at multiple scales - local, state, and federal. This poster demonstrates multiple GIS-based approaches to delimiting floodplains and contrasts these with observed flooding events from a majo...

  12. Ecohydrological consequences of non-native riparian vegetation in the southwestern United States: A review from an ecophysiological perspective

    Science.gov (United States)

    Hultine, K. R.; Bush, S. E.

    2011-07-01

    Protecting water resources for expanding human enterprise while conserving valued natural habitat is among the greatest challenges of the 21st century. Global change processes such as climate change and intensive land use pose significant threats to water resources, particularly in arid regions where potential evapotranspiration far exceeds annual rainfall. Potentially compounding these shortages is the progressive expansion of non-native plant species in riparian areas along streams, canals and rivers in geographically arid regions. This paper sets out to identify when and where non-native riparian plant species are likely to have the highest potential impact on hydrologic fluxes of arid and semiarid river systems. We develop an ecophysiological framework that focuses on two main criteria: (1) examination of the physiological traits that promote non-native species establishment and persistence across environmental gradients, and (2) assessment of where and to what extent hydrologic fluxes are potentially altered by the establishment of introduced species at varying scales from individual plants, to small river reaches, to entire river basins. We highlight three non-native plant species that currently dominate southwestern United States riparian forests. These include tamarisk (Tamarix spp.), Russian olive (Eleagnus angustifolia), and Russian knapweed (Acroptilon repens). As with other recent reviews, we suspect that in many cases the removal of these, and other non-native species will have little or no impact on either streamflow volume or groundwater levels. However, we identify potential exceptions where the expansion of non-native plant species could have significant impact on ecohydrologic processes associated with southwestern United States river systems. Future research needs are outlined that will ultimately assist land managers and policy makers with restoration and conservation priorities to preserve water resources and valued riparian habitat given

  13. Riparian trees as common denominators across the river flow ...

    African Journals Online (AJOL)

    Riparian tree species, growing under different conditions of water availability, can ... leaf area and increasing wood density correlating with deeper groundwater levels. ... and Sanddrifskloof Rivers (South Africa) under reduced flow conditions.

  14. The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams

    Science.gov (United States)

    Michael G. Dosskey; Philippe Vidon; Noel P. Gurwick; Craig J. Allan; Tim P. Duval; Richard Lowrance

    2010-01-01

    We review the research literature and summarize the major processes by which riparian vegetation influences chemical water quality in streams, as well as how these processes vary among vegetation types, and discuss how these processes respond to removal and restoration of riparian vegetation and thereby determine the timing and level of response in stream water quality...

  15. Impacts of an invasive snail (Tarebia granifera) on nutrient cycling in tropical streams: the role of riparian deforestation in Trinidad, West Indies.

    Science.gov (United States)

    Moslemi, Jennifer M; Snider, Sunny B; Macneill, Keeley; Gilliam, James F; Flecker, Alexander S

    2012-01-01

    Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N) cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three Neotropical streams, we measured snail biomass and N excretion in open and closed canopy habitats to generate estimates of mass- and area-specific N excretion rates. Snail biomass was 2 to 8 times greater and areal N excretion rates ranged from 3 to 9 times greater in open canopy habitats. Snails foraging in open canopy habitat also had access to more abundant food resources and exhibited greater growth and mass-specific N excretion rates. Estimates of ecosystem N demand indicated that snail N excretion in fully closed, partially closed, and open canopy habitats supplied 2%, 11%, and 16% of integrated ecosystem N demand, respectively. We conclude that human-mediated riparian canopy loss can generate hotspots of snail biomass, growth, and N excretion along tropical stream networks, altering the impacts of an invasive snail on the biogeochemical cycling of N.

  16. Modeling the Effects of Hydrogeomorphology and Climactic Factors on Nitrogen, Phosphorus, and Greenhouse Gas Dynamics in Riparian Zones.

    Science.gov (United States)

    Hassanzadeh, Y.; Vidon, P.; Gold, A.; Pradhanang, S. M.; Addy, K.

    2017-12-01

    Vegetated riparian zones are often considered for use as best management practices to mitigate the impacts of agriculture on water quality. However, riparian zones can also be a source of greenhouse gases and their influence on water quality varies depending on landscape hydrogeomorphic characteristics and climate. Methods used to evaluate riparian zone functions include conceptual models, and spatially explicit and process based models (REMM), but very few attempts have been made to connect riparian zone characteristics with function using easily accessible landscape scale data. Here, we present comprehensive statistical models that can be used to assess riparian zone functions with easily obtainable landscape-scale hydrogeomorphic attributes and climate data. Models were developed from a database spanning 88 years and 36 sites. Statistical methods including principal component analysis and stepwise regression were used to reduced data dimensionality and identify significant predictors. Models were validated using additional data collected from scientific literature. The 8 models developed connect landscape characteristics to nitrogen and phosphorus concentration and removal (1-4), greenhouse gas emissions (5-7), and water table depth (8). Results show the range of influence that various climate and landscape characteristics have on riparian zone functions, and the tradeoffs that exist with regards to nitrogen, phosphorous, and greenhouse gases. These models will help reduce the need for extensive field measurements and help scientists and land managers make more informed decisions regarding the use of riparian zones for water quality management.

  17. A read-out buffer prototype for ATLAS high level triggers

    CERN Document Server

    Calvet, D; Huet, M; Le Dû, P; Mandjavidze, I D; Mur, M

    2000-01-01

    Read-Out Buffers are critical components in the dataflow chain of the ATLAS Trigger/DAQ system. At up to 75 kHz, after each Level-1 trigger accept signal, these devices receive and store digitized data from groups of front-end electronic channels. Several Read-Out Buffers are grouped to form a Read-Out Buffer Complex that acts as a data server for the High Level Triggers selection algorithms and for the final data collection system. This paper describes a functional prototype of a Read-Out Buffer based on a custom made PCI mezzanine card that is designed to accept input data at up to 160 MB/s, to store up to 8 MB of data and to distribute data chunks at the desired request rate. We describe the hardware of the card that is based on an Intel I960 processor and CPLDs. We present the integration of several of these cards in a Read-Out Buffer Complex. We measure various performance figures and we discuss to which extent these can fulfill ATLAS needs. 5 Refs.

  18. Two-Buffer Simulation Games

    Directory of Open Access Journals (Sweden)

    Milka Hutagalung

    2016-07-01

    Full Text Available We consider simulation games played between Spoiler and Duplicator on two Büchi automata in which the choices made by Spoiler can be buffered by Duplicator in two different buffers before she executes them on her structure. Previous work on such games using a single buffer has shown that they are useful to approximate language inclusion problems. We study the decidability and complexity and show that games with two buffers can be used to approximate corresponding problems on finite transducers, i.e. the inclusion problem for rational relations over infinite words.

  19. Temperature Buffer Test. Measurements of water content and density of the excavated buffer material

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik [Clay Technology AB, Lund (Sweden)

    2010-12-15

    TBT (Temperature Buffer Test) is a joint project between SKB/ANDRA and supported by ENRESA (modeling) and DBE (instrumentation), which aims at understanding and modeling the thermo-hydromechanical behavior of buffers made of swelling clay submitted to high temperatures (over 100 deg C) during the water saturation process. The test was carried out at the - 420 m level in Aespoe HRL in a 8 meters deep and 1.76 m diameter deposition hole, with two heaters (3 m long, 0.6 m diameter), surrounded by a MX-80 bentonite buffer and a confining plug on top anchored with 9 rods. It was installed during spring 2003. The bentonite around upper heater was removed during the period October - December 2009 and the buffer around the lower heater was removed during January - Mars 2010. During dismantling of the buffer, samples were taken on which analyses were made. This report describes the work with the deteroemoeination of the water content and the density of the taken samples. Most of the samples were taken from the buffer by core drilling from the upper surface of each installed bentonite block. The cores had a diameter of about 50 mm and a maximum length equal to the original height of the bentonite blocks (about 500 mm). The water content of the buffer was determined by drying a sample at a temperature of 105 deg C for 24 h and the bulk density was determined by weighing a sample both in the air and immerged in paraffin oil with known density. The water content, dry density, degree of saturation and void ratio of the buffer were then plotted. The plots show that all parts of the buffer had taken up water and the degree of saturation of the buffer varied between 90 - 100%. Large variation in the dry density of the buffer was also observed.

  20. Which offers more scope to suppress river phytoplankton blooms: reducing nutrient pollution or riparian shading?

    Science.gov (United States)

    Hutchins, M G; Johnson, A C; Deflandre-Vlandas, A; Comber, S; Posen, P; Boorman, D

    2010-10-01

    River flow and quality data, including chlorophyll-a as a surrogate for river phytoplankton biomass, were collated for the River Ouse catchment in NE England, which according to established criteria is a largely unpolluted network. Against these data, a daily river quality model (QUESTOR) was setup and successfully tested. Following a review, a river quality classification scheme based on phytoplankton biomass was proposed. Based on climate change predictions the model indicated that a shift from present day oligotrophic/mesotrophic conditions to a mesotrophic/eutrophic system could occur by 2080. Management options were evaluated to mitigate against this predicted decline in quality. Reducing nutrient pollution was found to be less effective at suppressing phytoplankton growth than the less costly option of establishing riparian shading. In the Swale tributary, ongoing efforts to reduce phosphorus loads in sewage treatment works will only reduce peak (95th percentile) phytoplankton by 11%, whereas a reduction of 44% is possible if riparian tree cover is also implemented. Likewise, in the Ure, whilst reducing nitrate loads by curtailing agriculture in the headwaters may bring about a 10% reduction, riparian shading would instead reduce levels by 47%. Such modelling studies are somewhat limited by insufficient field data but offer a potentially very valuable tool to assess the most cost-effective methods of tackling effects of eutrophication. Copyright 2010 Elsevier B.V. All rights reserved.

  1. Chinese Privet (Ligustrum sinense) removal and its effect on native plant communities of Riparian Forests

    Science.gov (United States)

    James Hanula; Scott Horn; John W. Taylor

    2010-01-01

    Chinese privet is a major invasive shrub within riparian zones throughout the southeastern United States. Weremoved privet shrubs from four riparian forests in October 2005 with a GyrotracH mulching machine or by handfelling with chainsaws and machetes to determine how well these treatments controlled privet and how they affected plant...

  2. Buffer design 2012

    International Nuclear Information System (INIS)

    Juvankoski, M.

    2013-08-01

    Posiva's spent nuclear fuel disposal is based on the KBS-3V concept and on the characteristics of the Olkiluoto site. In this concept single canisters containing spent nuclear fuel surrounded by a bentonite buffer are emplaced in individual vertical boreholes drilled in the floor of deposition tunnels in bedrock at about 420 m depth below ground level. Disk type bentonite blocks are installed at the bottom of the hole and on the top of the disposal canister. Ring type bentonite blocks surround the canisters. This report describes the detailed design of the buffer for a KBS-3V repository. The report presents the design basis, the reference design, and summarises the performance analyses carried out for the design. This report addresses aspects concerning the manufacture, quality control, mechanical strength, chemical resistance, thermal dimensioning, handling of buffer components and material ageing phenomena including the effect of radiation. Interaction of buffer and other engineered barriers are included in the study. The long-term evolution of the repository and its effective drivers are considered if they have an impact on the buffer performance but operational safety aspects are also included because they may affect long-term safety. (orig.)

  3. Influence of buffer zone concentrations on efficiency in partial filling micellar electrokinetic chromatography.

    Science.gov (United States)

    Michalke, D; Kolb, S; Welsch, T

    2001-05-04

    The potential of counter pressure-moderated partial filling micellar electrokinetic chromatography (PF-MEKC) was investigated in this work. Plate numbers of homologous omega-phenylalcohols were measured in a two-plug PF-MEKC system varying the concentrations and hence the ionic strengths of the background buffer compared to the sodium dodecyl sulfate-containing separation buffer and the counter pressure on the cathodic buffer reservoir. It was observed that plate numbers are strongly influenced by both the buffer concentrations and the counter pressure. Highest plate numbers were obtained with a buffer system where the concentrations are adjusted such that the electroosmotic flow velocities in both zones are equal. Differences in the local electroosmotic flow velocities of the zones caused by different buffer concentrations are responsible for tremendously reduced plate numbers. The efficiency drop is explained in several models by the formation of an intersegmental pressure which produces a parabolically shaped laminar flow component in both zones. Thus, the electroosmotic plug-like flow profile is distorted and the efficiency is reduced. The effect of counter pressure on efficiency turned out to be very complex in dependence on the buffer system applied.

  4. Average rainwater pH, concepts of atmospheric acidity, and buffering in open systems

    Energy Technology Data Exchange (ETDEWEB)

    Liljestrand, H.M.

    1985-01-01

    The system of water equilibrated with a constant partial pressure of CO/sub 2/, as a reference point for pH acidity-alkalinity relationships, has nonvolatile acidity and alkalinity components as conservative quantities, but not (H/sup +/). Simple algorithms are presented for the determination of the average pH for combinations of samples both above and below pH 5.6. Averaging the nonconservative quantity (H/sup +/) yields erroneously low mean pH values. To extend the open CO/sub 2/ system to include other volatile atmospheric acids and bases distributed among the gas, liquid and particulate matter phases, a theoretical framework for atmospheric acidity is presented. Within certain oxidation-reduction limitations, the total atmospheric acidity (but not free acidity) is a conservative quantity. The concept of atmospheric acidity is applied to air-water systems approximating aerosols, fogwater, cloudwater and rainwater. The buffer intensity in hydrometers is described as a function of net strong acidity, partial pressures of acid and base gases and the water to air ratio. For high liquid to air volume ratios, the equilibrium partial pressures of trace acid and base gases are set by the pH or net acidity controlled by the nonvolatile acid and base concentrations. For low water to air volume ratios as well as stationary state systems such as precipitation scavenging with continuous emissions, the partial pressures of trace gases (NH/sub 3/, HCl, NHO/sub 3/, SO/sub 2/, and CH/sub 3/COOH) appear to be of greater or equal importance as carbonate species as buffers in the aqueous phase.

  5. Average rainwater pH, concepts of atmospheric acidity, and buffering in open systems

    Science.gov (United States)

    Liljestrand, Howard M.

    The system of water equilibrated with a constant partial pressure of CO 2, as a reference point for pH acidity-alkalinity relationships, has nonvolatile acidity and alkalinity components as conservative quantities, but not [H +]. Simple algorithms are presented for the determination of the average pH for combinations of samples both above and below pH 5.6. Averaging the nonconservative quantity [H +] yields erroneously low mean pH values. To extend the open CO 2 system to include other volatile atmospheric acids and bases distributed among the gas, liquid and particulate matter phases, a theoretical framework for atmospheric acidity is presented. Within certain oxidation-reduction limitations, the total atmospheric acidity (but not free acidity) is a conservative quantity. The concept of atmospheric acidity is applied to air-water systems approximating aerosols, fogwater, cloudwater and rainwater. The buffer intensity in hydrometeors is described as a function of net strong acidity, partial pressures of acid and base gases and the water to air ratio. For high liquid to air volume ratios, the equilibrium partial pressures of trace acid and base gases are set by the pH or net acidity controlled by the nonvolatile acid and base concentrations. For low water to air volume ratios as well as stationary state systems such as precipitation scavenging with continuous emissions, the partial pressures of trace gases (NH 3, HCl, HNO 3, SO 2 and CH 3COOH) appear to be of greater or equal importance as carbonate species as buffers in the aqueous phase.

  6. Molecular Buffers Permit Sensitivity Tuning and Inversion of Riboswitch Signals

    DEFF Research Database (Denmark)

    Rugbjerg, Peter; Genee, Hans Jasper; Jensen, Kristian

    2016-01-01

    transcription factor, while interacting DNA-binding domains mediate the transduction of signal and form an interacting molecular buffer. The molecular buffer system enables modular signal inversion through integration with repressor modules. Further, tuning of input sensitivity was achieved through perturbation...

  7. Success and failure with phthalate buffers in capillary zone electrophoresis

    NARCIS (Netherlands)

    Bocek, P.; Gebauer, P.; Beckers, J.L.

    2001-01-01

    Phthalate buffers are currently used in capillary electrophoresis as robust electrolyte systems for indirect detection. This contribution demonstrates that these buffers show regularly not only successful regions of mobilities of analytes (sample window) but also regions of failure where the

  8. Transformation of an Industrial Brownfield into an Ecological Buffer for Michigan’s Only Ramsar Wetland of International Importance

    Directory of Open Access Journals (Sweden)

    Greg Norwood

    2012-05-01

    Full Text Available The Detroit River International Wildlife Refuge spans 77 km along the Detroit River and western Lake Erie, and is the only unit of the National Wildlife Refuge System that is international. A key unit of the refuge is the 166-ha Humbug Marsh that represents the last kilometer of natural shoreline on the U.S. mainland of the river and Michigan’s only “Wetland of International Importance” designated under the 1971 International Ramsar Convention. Adjacent to Humbug Marsh is an 18-ha former industrial manufacturing site (now called the Refuge Gateway that is being remediated and restored as an ecological buffer for Humbug Marsh and the future home of the refuge’s visitor center. Restoration and redevelopment activities have included: cleanup and capping of contaminated lands; daylighting a creek (i.e., deliberately exposing the flow of a creek that was historically placed underground in a culvert and constructing a retention pond and emergent wetland to treat storm water prior to discharge to the Detroit River; restoring coastal wetland, riparian buffer, and upland habitats; and constructing two roads, hiking/biking trails, and a kayak/canoe landing to offer wildlife-compatible public uses that allow visitors to experience this internationally-recognized natural resource. This project has been described as transformational for the region by restoring an industrial brownfield into high quality wildlife habitat that expands the ecological buffer of a Ramsar site. Specific restoration targets for the site include: achieving a net gain of 6.5 ha of wetlands in a river that has lost 97% of its coastal wetlands to development; restoring 10.1 ha of upland buffer habitat; treating invasive Phragmites along 4 km of shoreline; and treatment of invasive plant species in 20.2 ha of upland habitats in Humbug Marsh. Further, the Refuge Gateway is being restored as a model of environmental sustainability for nearly seven million

  9. Nitrogen loss from anaerobic ammonium oxidation coupled to Iron(III) reduction in a riparian zone.

    Science.gov (United States)

    Ding, Bangjing; Li, Zhengkui; Qin, Yunbin

    2017-12-01

    Anaerobic ammonium oxidation coupled to iron(III) reduction (termed Feammox) is a recently discovered pathway of nitrogen cycling. However, little is known about the pathways of N transformation via Feammox process in riparian zones. In this study, evidence for Feammox in riparian zones with or without vegetation cover was demonstrated using isotope tracing technique and high-throughput sequencing technology. The results showed that Feammox could occur in riparian zones, and demonstrated that N 2 directly from Feammox was dominant Feammox pathway. The Feammox rates in vegetated soil samples was 0.32-0.37 mg N kg -1 d -1 , which is higher than that in un-vegetated soil samples (0.20 mg N kg -1 d -1 ). Moreover, the growth of vegetation led to a 4.99-6.41% increase in the abundance of iron reducing bacteria (Anaeromyxobacter, Pseudomonas and Geobacter) and iron reducing bacteria play an essential role in Feammox process. An estimated loss of 23.7-43.9 kg N ha -1 year -1 was associated with Feammox in the examined riparian zone. Overall, the co-occurrence of ammonium oxidation and iron reduction suggest that Feammox can play an essential role in the pathway of nitrogen removal in riparian zones. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Impact of native ungulates and beaver on riparian communities in the intermountain west

    OpenAIRE

    Kay, Charles E.

    1994-01-01

    This paper reviews the impact native ungulates, primarily elk and moose, and beaver can have on riparian communities in the Western United States. In Yellowstone National Park and in other areas where ungulates are not managed, repeated browsing has reduced tall willow, aspen, and cottonwood communities by approximately 95 percent since the late 1800's. Native ungulates can also severely reduce or eliminate palatable grasses and forbs from herbaceous riparian communities. By eliminating woody...

  11. An assessment of riparian environmental quality by using butterflies and disturbance susceptibility scores

    Science.gov (United States)

    Nelson, S. Mark; Andersen, Douglas C.

    1994-01-01

    The butterfly community at a revegetated riparian site on the lower Colorado River near Parker, Arizona, was compared to that found in a reference riparian site. Data indicated that the herbaceous plant community, which was lacking at the revegetated site, was important to several butterfly taxa. An index using butterfly sensitivity to habitat change (species classified into risk groups) and number of taxa was developed to monitor revegetation projects and to determine restoration effectiveness.

  12. Case studies of riparian and watershed restoration in the southwestern United States—Principles, challenges, and successes

    Science.gov (United States)

    Ralston, Barbara E.; Sarr, Daniel A.; Ralston, Barbara E.; Sarr, Daniel A.

    2017-07-18

    Globally, rivers and streams are highly altered by impoundments, diversions, and stream channelization associated with agricultural and water delivery needs. Climate change imposes additional challenges by further reducing discharge, introducing variability in seasonal precipitation patterns, and increasing temperatures. Collectively, these changes in a river or stream’s annual hydrology affects surface and groundwater dynamics, fluvial processes, and the linked aquatic and riparian responses, particularly in arid regions. Recognizing the inherent ecosystem services that riparian and aquatic habitats provide, society increasingly supports restoring the functionality of riparian and aquatic ecosystems.Given the wide range in types and scales of riparian impacts, approaches to riparian restoration can range from tactical, short-term, and site-specific efforts to strategic projects and long-term collaborations best pursued at the watershed scale. In the spirit of sharing information, the U.S. Geological Survey’s Grand Canyon Monitoring and Research Center convened a workshop June 23-25, 2015, in Flagstaff, Ariz. for practitioners in restoration science to share general principles, successful restoration practices, and discuss the challenges that face those practicing riparian restoration in the southwestern United States. Presenters from the Colorado River and the Rio Grande basins, offered their perspectives and experiences in restoration at the local, reach and watershed scale. Outcomes of the workshop include this Proceedings volume, which is composed of extended abstracts of most of the presentations given at the workshop, and recommendations or information needs identified by participants. The organization of the Proceedings follows a general progression from local scale restoration to river and watershed scale approaches, and finishes with restoration assessments and monitoring.

  13. Lean buffering in serial production lines with Bernoulli machines

    Directory of Open Access Journals (Sweden)

    A. B. Hu

    2006-01-01

    Full Text Available Lean buffering is the smallest buffer capacity necessary to ensure the desired production rate of a manufacturing system. In this paper, analytical methods for selecting lean buffering in serial production lines are developed under the assumption that the machines obey the Bernoulli reliability model. Both closed-form expressions and recursive approaches are investigated. The cases of identical and nonidentical machines are analyzed. Results obtained can be useful for production line designers and production managers to maintain the required production rate with the smallest possible inventories.

  14. Bird community structure in riparian environments in Cai River, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Jaqueline Brummelhaus

    2012-06-01

    Full Text Available Urbanization produces changes in riparian environments, causing effects in the structure of bird communities, which present different responses to the impacts. We compare species richness, abundance, and composition of birds in riparian environments with different characteristics in Cai River, Rio Grande do Sul, Brazil. We carried out observations in woodland, grassland, and urban environments, between September 2007 and August 2008. We listed 130 bird species, 29 species unique to woodland environment, and an endangeredspecies: Triclaria malachitacea. Bird abundance differed from woodland (n = 426 individuals to urban environments (n = 939 individuals (F2,6 = 7.315; P = 0.025. Species composition and feeding guilds differed significantly in the bird community structures among these three riparian environments. In the grassland and urban environments there were more generalist insectivorous species, while in the woodland environments we find more leaf and trunk insectivorous species and frugivorous species, sensitive to human impacts. Bird species can be biological quality indicators and they contribute to ecosystems performing relevant functions. With the knowledge on bird community structure and their needs, it is possible to implement management practices for restoration of degraded riparian environments.

  15. Scientific Applications Performance Evaluation on Burst Buffer

    KAUST Repository

    Markomanolis, George S.

    2017-10-19

    Parallel I/O is an integral component of modern high performance computing, especially in storing and processing very large datasets, such as the case of seismic imaging, CFD, combustion and weather modeling. The storage hierarchy includes nowadays additional layers, the latest being the usage of SSD-based storage as a Burst Buffer for I/O acceleration. We present an in-depth analysis on how to use Burst Buffer for specific cases and how the internal MPI I/O aggregators operate according to the options that the user provides during his job submission. We analyze the performance of a range of I/O intensive scientific applications, at various scales on a large installation of Lustre parallel file system compared to an SSD-based Burst Buffer. Our results show a performance improvement over Lustre when using Burst Buffer. Moreover, we show results from a data hierarchy library which indicate that the standard I/O approaches are not enough to get the expected performance from this technology. The performance gain on the total execution time of the studied applications is between 1.16 and 3 times compared to Lustre. One of the test cases achieved an impressive I/O throughput of 900 GB/s on Burst Buffer.

  16. Implementing the countercyclical capital buffer in South Africa: Practical considerations

    OpenAIRE

    Pravin Burra; Pieter Juriaan de Jongh; Helgard Raubenheimer; Gary van Vuuren; Henco Wiid

    2015-01-01

    The Basel II regulatory framework significantly increased the resilience of the banking system, but proved ineffective in preventing the 2008/9 financial crisis. The subsequent introduction of Basel III aimed, inter alia, to supplement bank capital using buffers. The countercyclical buffer boosts existing minimum capital requirements when systemic risk surges are detected. Bolstering capital in favourable economic conditions cushions losses in unfavourable conditions, thereby addressing capit...

  17. Potential effects of climate change on riparian areas, wetlands, and groundwater-dependent ecosystems in the Blue Mountains, Oregon, USA

    Directory of Open Access Journals (Sweden)

    Kathleen A. Dwire

    2018-04-01

    Full Text Available Riparian areas, wetlands, and groundwater-dependent ecosystems, which are found at all elevations throughout the Blue Mountains, comprise a small portion of the landscape but have high conservation value because they provide habitat for diverse flora and fauna. The effects of climate change on these special habitats may be especially profound, due to altered snowpack and hydrologic regimes predicted to occur in the near future. The functionality of many riparian areas is currently compromised by water diversions and livestock grazing, which reduces their resilience to additional stresses that a warmer climate may bring. Areas associated with springs and small streams will probably experience near-term changes, and some riparian areas and wetlands may decrease in size over time. A warmer climate and reduced soil moisture could lead to a transition from riparian hardwood species to more drought tolerant conifers and shrubs. Increased frequency and spatial extent of wildfire spreading from upland forests could also affect riparian species composition. The specific effects of climate change will vary, depending on local hydrology (especially groundwater, topography, streamside microclimates, and current conditions and land use. Keywords: Climate change, Groundwater-dependent ecosystems, Riparian areas, Springs, Wetlands

  18. Accelerating Science with the NERSC Burst Buffer Early User Program

    Energy Technology Data Exchange (ETDEWEB)

    Bhimji, Wahid [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bard, Debbie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Romanus, Melissa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutgers Univ., New Brunswick, NJ (United States); Paul, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ovsyannikov, Andrey [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Friesen, Brian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bryson, Matt [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Correa, Joaquin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lockwood, Glenn K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsulaia, Vakho [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Byna, Suren [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Farrell, Steve [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gursoy, Doga [Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS); Daley, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Beckner, Vince [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Van Straalen, Brian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Trebotich, David [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tull, Craig [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Weber, Gunther H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wright, Nicholas J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Antypas, Katie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Prabhat, none [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-01-01

    NVRAM-based Burst Buffers are an important part of the emerging HPC storage landscape. The National Energy Research Scientific Computing Center (NERSC) at Lawrence Berkeley National Laboratory recently installed one of the first Burst Buffer systems as part of its new Cori supercomputer, collaborating with Cray on the development of the DataWarp software. NERSC has a diverse user base comprised of over 6500 users in 700 different projects spanning a wide variety of scientific computing applications. The use-cases of the Burst Buffer at NERSC are therefore also considerable and diverse. We describe here performance measurements and lessons learned from the Burst Buffer Early User Program at NERSC, which selected a number of research projects to gain early access to the Burst Buffer and exercise its capability to enable new scientific advancements. To the best of our knowledge this is the first time a Burst Buffer has been stressed at scale by diverse, real user workloads and therefore these lessons will be of considerable benefit to shaping the developing use of Burst Buffers at HPC centers.

  19. Effect of river flow fluctuations on riparian vegetation dynamics: Processes and models

    Science.gov (United States)

    Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca

    2017-12-01

    Several decades of field observations, laboratory experiments and mathematical modelings have demonstrated that the riparian environment is a disturbance-driven ecosystem, and that the main source of disturbance is river flow fluctuations. The focus of the present work has been on the key role that flow fluctuations play in determining the abundance, zonation and species composition of patches of riparian vegetation. To this aim, the scientific literature on the subject, over the last 20 years, has been reviewed. First, the most relevant ecological, morphological and chemical mechanisms induced by river flow fluctuations are described from a process-based perspective. The role of flow variability is discussed for the processes that affect the recruitment of vegetation, the vegetation during its adult life, and the morphological and nutrient dynamics occurring in the riparian habitat. Particular emphasis has been given to studies that were aimed at quantifying the effect of these processes on vegetation, and at linking them to the statistical characteristics of the river hydrology. Second, the advances made, from a modeling point of view, have been considered and discussed. The main models that have been developed to describe the dynamics of riparian vegetation have been presented. Different modeling approaches have been compared, and the corresponding advantages and drawbacks have been pointed out. Finally, attention has been paid to identifying the processes considered by the models, and these processes have been compared with those that have actually been observed or measured in field/laboratory studies.

  20. Thermophysical properties of carboxylic and amino acid buffers at subzero temperatures: relevance to frozen state stabilization.

    Science.gov (United States)

    Sundaramurthi, Prakash; Suryanarayanan, Raj

    2011-06-02

    Macromolecules and other thermolabile biologicals are often buffered and stored in frozen or dried (freeze-dried) state. Crystallization of buffer components in frozen aqueous solutions and the consequent pH shifts were studied in carboxylic (succinic, malic, citric, tartaric acid) and amino acid (glycine, histidine) buffers. Aqueous buffer solutions were cooled from room temperature (RT) to -25 °C and the pH of the solution was measured as a function of temperature. The thermal behavior of frozen solutions was investigated by differential scanning calorimetry (DSC), and the crystallized phases were identified by X-ray diffractometry (XRD). Based on the solubility of the neutral species of each buffer system over a range of temperatures, it was possible to estimate its degree of supersaturation at the subambient temperature of interest. This enabled us to predict its crystallization propensity in frozen systems. The experimental and the predicted rank orderings were in excellent agreement. The malate buffer system was robust with no evidence of buffer component crystallization and hence negligible pH shift. In the citrate and tartrate systems, at initial pH pI. In the histidine buffer system, depending on the initial pH, either histidine or histidine HCl crystallized.

  1. The interactive effects of climate change, riparian management, and a nonnative predator on stream-rearing salmon.

    Science.gov (United States)

    Lawrence, David J; Stewart-Koster, Ben; Olden, Julian D; Ruesch, Aaron S; Torgersen, Christian E; Lawler, Joshua J; Butcher, Don P; Crown, Julia K

    2014-06-01

    Predicting how climate change is likely to interact with myriad other stressors that threaten species of conservation concern is an essential challenge in aquatic ecosystems. This study provides a framework to accomplish this task in salmon-bearing streams of the northwestern United States, where land-use-related reductions in riparian shading have caused changes in stream thermal regimes, and additional warming from projected climate change may result in significant losses of coldwater fish habitat over the next century. Predatory, nonnative smallmouth bass have also been introduced into many northwestern streams, and their range is likely to expand as streams warm, presenting an additional challenge to the persistence of threatened Pacific salmon. The goal of this work was to forecast the interactive effects of climate change, riparian management, and nonnative species on stream-rearing salmon and to evaluate the capacity of restoration to mitigate these effects. We intersected downscaled global climate forecasts with a local-scale water temperature model to predict mid- and end-of-century temperatures in streams in the Columbia River basin. We compared one stream that is thermally impaired due to the loss of riparian vegetation and another that is cooler and has a largely intact riparian corridor. Using the forecasted stream temperatures in conjunction with fish-habitat models, we predicted how stream-rearing chinook salmon and bass distributions would change as each stream warmed. In the highly modified stream, end-of-century warming may cause near total loss of chinook salmon-rearing habitat and a complete invasion of the upper watershed by bass. In the less modified stream, bass were thermally restricted from the upstream-most areas. In both systems, temperature increases resulted in higher predicted spatial overlap between stream-rearing chinook salmon and potentially predatory bass in the early summer (two- to fourfold increase) and greater abundance of

  2. [Ocular surface acidity and buffering system (by studying the conjunctival sac)].

    Science.gov (United States)

    Avetisov, S É; Safonova, T N; Novikov, I A; Pateiuk, L S; Griboedova, I G

    2014-01-01

    As any mucous membrane the conjunctiva is characterized by a definite pH value which guarantees-physiological functioning of the ocular surface. The most commonly used method of assessment is potentiometric pH measurement with ion-specific glass microelectrodes. The results, however, can be affected by such factors, as conjunctival sac zoning, tissue acidity, epithelial trauma, and reflex tear secretion. Few data and hypotheses are available on mechanisms of maintaining the acid-base balance of the conjunctival sac (bicarbonate buffering system in particular). to study spatial variability of conjunctival tear fluid pH and possible mechanisms of its maintenance using original methods of acidity measurement and mineral content assessment. Tear pH was determined in 42 healthy participants (84 eyes) by means of litmus test strips and computer- aided colorimetry. Electron probe microanalysis in combination with energy dispersive spectrometry was performed in 8 healthy participants (8 eyes, 8 samples). In the group of 42 healthy participants (84 eyes) the pH value of conjunctival tear fluid varied from 6.30 to 7.23 with the average of 6.76 and pH mode 6.74. The pH value of conjunctival mucous discharge was measured in 25 healthy participants (28 eyes) and varied from 7.00 to 8.00 with the average of 7.26 and pH mode 7.30. The main mineral components of tear fluid are chlorine, sodium, potassium, and boron. Borate buffer is regarded as a mechanism of maintaining the acid-base balance of the ocular surface. The developed method of pH measurement ensuresreliable determination of conjunctival sac acidity in accordance with zoning and heterogeneity of its media as well as the complex structure of the tear film. In a healthy population, the acidity of tear significantly differs from that of conjunctival mucous discharge. Soluble chlorine, sodium, potassium, and boron compounds are the prevailing mineral components of tear fluid. Borate buffer appears to be the most stable of

  3. Surface runoff generation in a small watershed covered by sugarcane and riparian forest

    Directory of Open Access Journals (Sweden)

    Rafael Pires Fernandes

    2013-12-01

    Full Text Available Since an understanding of how runoff is generated is of great importance to soil conservation, to water availability and to the management of a watershed, the objective of this study was to understand the generation of surface runoff in a watershed covered by sugarcane and riparian forest. Nine surface runoff plots were set up, evenly distributed on the lower, middle and upper slopes. The lower portion was covered by riparian forest. We showed that the average surface runoff coefficient along the slope in the present study was higher than in other studies under different land uses. Furthermore, the surface runoff was higher under sugarcane compared to the riparian forest, especially after sugarcane harvesting. Besides land cover, other factors such as the characteristics of rainfall events, relief and physical soil characteristics such as soil bulk density and saturated hydraulic conductivity influenced the surface runoff generation.

  4. Complexation of buffer constituents with neutral complexation agents: part II. Practical impact in capillary zone electrophoresis.

    Science.gov (United States)

    Beneš, Martin; Riesová, Martina; Svobodová, Jana; Tesařová, Eva; Dubský, Pavel; Gaš, Bohuslav

    2013-09-17

    This article elucidates the practical impact of the complexation of buffer constituents with complexation agents on electrophoretic results, namely, complexation constant determination, system peak development, and proper separation of analytes. Several common buffers, which were selected based on the pH study in Part I of this paper series (Riesová, M.; Svobodová, J.; Tošner, Z.; Beneš, M.; Tesařová, E.; Gaš, B. Anal. Chem., 2013, DOI: 10.1021/ac4013804); e.g., CHES, MES, MOPS, Tricine were used to demonstrate behavior of such complex separation systems. We show that the value of a complexation constant determined in the interacting buffers environment depends not only on the analyte and complexation agent but it is also substantially affected by the type and concentration of buffer constituents. As a result, the complexation parameters determined in the interacting buffers cannot be regarded as thermodynamic ones and may provide misleading information about the strength of complexation of the compound of interest. We also demonstrate that the development of system peaks in interacting buffer systems significantly differs from the behavior known for noncomplexing systems, as the mobility of system peaks depends on the concentration and type of neutral complexation agent. Finally, we show that the use of interacting buffers can totally ruin the results of electrophoretic separation because the buffer properties change as the consequence of the buffer constituents' complexation. As a general conclusion, the interaction of buffer constituents with the complexation agent should always be considered in any method development procedures.

  5. Introducing buffer inventories in the RBD analysis of process production systems

    International Nuclear Information System (INIS)

    Macchi, Marco; Kristjanpoller, Fredy; Garetti, Marco; Arata, Adolfo; Fumagalli, Luca

    2012-01-01

    The throughput analysis is an important issue for the design and operations management of process production lines. The throughput of a line depends on the availability and nominal throughput of its machines. Further on, it is influenced by the accumulation process of production material stocked into buffers along the line; hence, the buffer inventory level is also a relevant variable that has to be considered when assessing the throughput of the line. The present paper is particularly concerned with using such an assessment for supporting maintenance decisions. The buffer inventory level should provide the proper isolation time before the buffer becomes empty, so that, during this time, a maintenance intervention can be carried on at a failed machine upward, without causing a propagation of the effect of the failure in the machines downward (the so called ‘material starvation’). Alike, it should guarantee the proper isolation time before reaching the complete utilisation of the buffer capacity, so that also during this time a maintenance intervention is possible at a failed machine downward without causing a propagation of the effect of the failure in the machines upward (the so called ‘blocking of production’). This strategy is particularly interesting in the process industry where the capital cost of equipment is high and the holding cost of material is low. Hence, the isolation times before reaching ‘material starvation’ or ‘blocking of production’ have to be properly studied in order to make an accurate analysis of their effect on the throughput of the line. The present paper provides a model to this end, derived by extending the well known Reliability Block Diagram (RBD) method, currently used in the normal duties of a maintenance engineer. The usual RBD availability analysis is integrated by a state space analysis through which isolation times can be analysed. Besides, an empirical study – the case of a production line taken out from the

  6. The stochastic nuclide transport model for buffer/backfill materials

    International Nuclear Information System (INIS)

    Ma Liping; Han Yongguo

    2014-01-01

    Currently, study on nuclide migration law in geological disposal repository of high level waste is assumed buffer/backfill layer to be continuous medium, utilized the continuity equation, equation of state, the equations of motion, etc, formed a set of theory and method to estimate nuclide concentration distribution in buffer/backfill layer, and provided an important basis for nuclide migration rules of repository. However, it is necessary to study the buffer/backfill layer microstructure and subtly describe the pore structure and fracture system of the buffer/backfill layer, and reflect the changes in connectivity and in different directions of the buffer/backfill layer. Through using random field theory, the nuclide transport for the buffer/backfill layer in geological disposal repository of nuclear waste is described in the paper. This paper mainly includes that, t represents the time, ξ t ⊂ Z d = d represents the integer lattice, Z represents collectivity integers, d = l, 2, 3, for instance, d = 2, Z d = {(m, n) : m, n ∈ Z} the state point of ξ t is typically considered to be occupied by the nuclide concentration values of the buffer/backfill layer, ξ t also represents random set in the diagram of two dimensional integer lattice, namely, t ∈ [0, T], {ξ t ,0 ≤ t ≤ ⊂ T} Consequently, according to the stochastic process obtained above, the changes of the nuclide concentration values of the buffer/backfill layer or the buffer/backfill laboratory materials in the repository with the time can be known. (authors)

  7. 21 CFR 520.1696a - Buffered penicillin powder, penicillin powder with buffered aqueous diluent.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Buffered penicillin powder, penicillin powder with... FORM NEW ANIMAL DRUGS § 520.1696a Buffered penicillin powder, penicillin powder with buffered aqueous diluent. (a) Specifications. When reconstituted, each milliliter contains penicillin G procaine equivalent...

  8. 78 FR 76317 - Llano Seco Riparian Sanctuary Unit Restoration and Pumping Plant/Fish Screen Facility Protection...

    Science.gov (United States)

    2013-12-17

    ...-FF08RSRC00] Llano Seco Riparian Sanctuary Unit Restoration and Pumping Plant/ Fish Screen Facility Protection... and Wildlife (CDFW), announce that the record of decision (ROD) for the Llano Seco Riparian Sanctuary...: www.fws.gov/refuge/sacramento river/ and http://www.riverpartners.org/where-we-work/sanctuary...

  9. Diffusivity database (DDB) system for major rocks and buffer materials (Released on 2007/specification)

    International Nuclear Information System (INIS)

    Tochigi, Yoshikatsu; Shibata, Masahiro; Sato, Haruo; Kitamura, Akira

    2007-03-01

    The Diffusivity Database (DDB) System developed on early 2006 was upgraded to apply the data of effective diffusion coefficient of the nuclides in the rock matrix for the 'H12: Project to Establish the Scientific and Technical Basis for HLW Disposal in Japan', and the data in the buffer materials from literature survey was newly added. Some functions of data search and selection were reformed to improve the level of convenience. This DDB system (work on MS-Access TM ) is released to the public through Web server managed by JAEA. (author)

  10. Using a conceptual model to assess the role of flow regulation in the hydromorphological evolution of riparian corridors

    Science.gov (United States)

    Martínez-Fernández, Vanesa; Gonzalez del Tánago, Marta; García de Jalón, diego

    2017-04-01

    Riparian corridors result from active vegetation-fluvial interactions, which are highly dependent on flow regime conditions and sediment dynamics. Colonization, establishment and survival of species are constrained by fluvial processes which vary according to topographic and sedimentological complexity of the corridor. In order to manage these dynamic and complex riparian systems there is a need for practical tools based on conceptual models. The objective of this study was to apply the conceptual model of riparian corridors lateral zonation in response to the dominant fluvial processes established by Gurnell et al. (2015) and verify its usefulness as a tool for assessing the effect of flow regulation. Two gravel rivers have been selected for this purpose from the north of Spain, the Porma River regulated by Boñar large dam and the unregulated Curueño River. The historical series of flows and the aerial photographs of 1956 and 2011 on which the river corridor has been delimited have been analyzed and identified the permanent inundated zone (1) and four areas of riparian vegetation dominated respectively by fluvial disturbance with coarse sediment erosion and deposition (zone 2), fluvial disturbance with finer sediment deposition (zone 3), inundation (zone 4) and soil moisture regime (zone 5). Likewise, a two-dimensional hydraulic simulation was performed with avenues of different return periods and calculated the prevailing hydraulic conditions (depths, velocities and drag forces) to characterize each of the vegetation zones mentioned in both rivers. The results show that the most active zone 2 (fluvial disturbance dominated showing coarse sediment erosion and deposition) disappears due to the regulation of flows and vegetation encroachment, while the riparian corridor is dominated by the less active zone where the vegetation is maintained by the humidity of sporadic floods and underground runoff. Moreover, by means of the hydraulic simulation we have found a

  11. Bird community structure in riparian environments in Cai River, Rio Grande do Sul, Brazil

    OpenAIRE

    Jaqueline Brummelhaus; Marcia Suelí Bohn; Maria Virginia Petry

    2012-01-01

    Urbanization produces changes in riparian environments, causing effects in the structure of bird communities, which present different responses to the impacts. We compare species richness, abundance, and composition of birds in riparian environments with different characteristics in Cai River, Rio Grande do Sul, Brazil. We carried out observations in woodland, grassland, and urban environments, between September 2007 and August 2008. We listed 130 bird species, 29 species unique to woodland e...

  12. Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying System

    KAUST Repository

    El Shafie, Ahmed

    2016-07-07

    This letter proposes a novel hybrid half-/full-duplex relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in the presence of a buffer-aided full-duplex relay node (Rooney) and a potential eavesdropper (Eve). Rooney adopts two different relaying, namely randomize-and-forward and decode-andforward relaying strategies, to improve the security of the legitimate system. In the first relaying strategy, Rooney uses a codebook different from that used at Alice. In the second relaying strategy, Rooney and Alice use the same codebooks. In addition, Rooney switches between half-duplex and full-duplex modes to further enhance the security of the legitimate system. The numerical results demonstrate that our proposed scheme achieves a significant average secrecy end-to-end throughput improvement relative to the conventional bufferless full-duplex relaying scheme.

  13. Physical-Layer Security of a Buffer-Aided Full-Duplex Relaying System

    KAUST Repository

    El Shafie, Ahmed; Salem, Ahmed Sultan; Al-Dhahir, Naofal

    2016-01-01

    This letter proposes a novel hybrid half-/full-duplex relaying scheme to enhance the relay channel security. A source node (Alice) communicates with her destination node (Bob) in the presence of a buffer-aided full-duplex relay node (Rooney) and a potential eavesdropper (Eve). Rooney adopts two different relaying, namely randomize-and-forward and decode-andforward relaying strategies, to improve the security of the legitimate system. In the first relaying strategy, Rooney uses a codebook different from that used at Alice. In the second relaying strategy, Rooney and Alice use the same codebooks. In addition, Rooney switches between half-duplex and full-duplex modes to further enhance the security of the legitimate system. The numerical results demonstrate that our proposed scheme achieves a significant average secrecy end-to-end throughput improvement relative to the conventional bufferless full-duplex relaying scheme.

  14. Scoping calculation of nuclides migration in engineering barrier system for effect of volume expansion due to overpack corrosion and intrusion of the buffer material

    International Nuclear Information System (INIS)

    Yoshita, Takashi; Ishihara, Yoshinao; Ishiguro, Katsuhiko; Ohi, Takao; Nakajima, Kunihiko

    1999-11-01

    Corrosion of the carbon steel overpack leads to a volume expansion since the specific gravity of corrosion products is smaller than carbon steel. The buffer material is compressed due to the corrosive swelling, reducing its thickness and porosity. On the other hand, buffer material may be extruded into fractures of the surrounding rock and this may lead to a deterioration of the planned functions of the buffer, including retardation of nuclides migration and colloid filtration. In this study, the sensitivity analyses for the effect of volume expansion and intrusion of the buffer material on nuclide migration in the engineering barrier system are carried out. The sensitivity analyses were performed on the decrease in the thickness of the buffer material in the radial direction caused by the corrosive swelling, and the change in the porosity and dry density of the buffer caused by both compacting due to corrosive swelling and intrusion of buffer material. As results, it was found the maximum release rates of relatively shorter half-life nuclides from the outside of the buffer material decreased for taking into account of a volume expansion due to overpack corrosion. On the other hand, the maximum release rates increased when the intrusion of buffer material was also taking into account. It was, however, the maximum release rates of longer half-life nuclides, such as Cs-137 and Np-237, were insensitive to the change of buffer material thickness, and porosity and dry density of buffer. (author)

  15. Carbon pools in stream-riparian corridors: legacy of disturbance along mountain streams of south-eastern Wyoming

    Science.gov (United States)

    Claire M. Ruffing; Kathleen A. Dwire; Melinda D. Daniels

    2016-01-01

    Streams and their accompanying riparian environments are intrinsic components of terrestrial carbon cycling. However, they have been understudied in terms of the magnitude of their storage components and the role of disturbance in determining carbon storage capacity. This study presents partial carbon budgets for stream-riparian corridors along six study...

  16. Study on chemical buffering property of GMZ sodium bentonite in air

    International Nuclear Information System (INIS)

    Wen Zhijian; Liu Yuemiao; Zong Zihua; Zhou Jia

    2008-01-01

    The high level radioactive wastes are characterized by very high initial radioactivity, the longer-lived actinides, many of actinides alpha-emitters. At present, the deep geological disposal is regarded as the most reasonable and effective way to safely disposal high-level radioactive wastes in the world. The conceptual model of HLW geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineered barrier system. The buffer is one of the engineered barrier materials and GMZ Na-bentonite is selected as the base material. The most important role related to buffer is chemical buffering, which means buffering of changes in water chemistry. This paper presents the experiments of GMZ-1 Na-bentonite reacted with distilled water in the air. The results and discussion of bench tests are reported. (authors)

  17. Hierarchical multi-taxa models inform riparian vs. hydrologic restoration of urban streams in a permeable landscape.

    Science.gov (United States)

    Gwinn, Daniel C; Middleton, Jen A; Beesley, Leah; Close, Paul; Quinton, Belinda; Storer, Tim; Davies, Peter M

    2018-03-01

    The degradation of streams caused by urbanization tends to follow predictable patterns; however, there is a growing appreciation for heterogeneity in stream response to urbanization due to the local geoclimatic context. Furthermore, there is building evidence that streams in mildly sloped, permeable landscapes respond uncharacteristically to urban stress calling for a more nuanced approach to restoration. We evaluated the relative influence of local-scale riparian characteristics and catchment-scale imperviousness on the macroinvertebrate assemblages of streams in the flat, permeable urban landscape of Perth, Western Australia. Using a hierarchical multi-taxa model, we predicted the outcomes of stylized stream restoration strategies to increase the riparian integrity at the local scale or decrease the influences of imperviousness at the catchment scale. In the urban streams of Perth, we show that local-scale riparian restoration can influence the structure of macroinvertebrate assemblages to a greater degree than managing the influences of catchment-scale imperviousness. We also observed an interaction between the effect of riparian integrity and imperviousness such that the effect of increased riparian integrity was enhanced at lower levels of catchment imperviousness. This study represents one of few conducted in flat, permeable landscapes and the first aimed at informing urban stream restoration in Perth, adding to the growing appreciation for heterogeneity of the Urban Stream Syndrome and its importance for urban stream restoration. © 2017 by the Ecological Society of America.

  18. Power Impact of Loop Buffer Schemes for Biomedical Wireless Sensor Nodes

    Directory of Open Access Journals (Sweden)

    Francky Catthoor

    2012-11-01

    Full Text Available Instruction memory organisations are pointed out as one of the major sources of energy consumption in embedded systems. As these systems are characterised by restrictive resources and a low-energy budget, any enhancement in this component allows not only to decrease the energy consumption but also to have a better distribution of the energy budget throughout the system. Loop buffering is an effective scheme to reduce energy consumption in instruction memory organisations. In this paper, the loop buffer concept is applied in real-life embedded applications that are widely used in biomedical Wireless Sensor Nodes, to show which scheme of loop buffer is more suitable for applications with certain behaviour. Post-layout simulations demonstrate that a trade-off exists between the complexity of the loop buffer architecture and the energy savings of utilising it. Therefore, the use of loop buffer architectures in order to optimise the instructionmemory organisation from the energy efficiency point of view should be evaluated carefully, taking into account two factors: (1 the percentage of the execution time of the application that is related to the execution of the loops, and (2 the distribution of the execution time percentage over each one of the loops that form the application.

  19. Tree species differentiation using intensity data derived from leaf-on and leaf-off airborne laser scanner data

    Science.gov (United States)

    Sooyoung Kim; Robert J. McGaughey; Hans-Erik Andersen; Gerard. Schreuder

    2009-01-01

    Tree species identification is important for a variety of natural resource management and monitoring activities including riparian buffer characterization, wildfire risk assessment, biodiversity monitoring, and wildlife habitat assessment. Intensity data recorded for each laser point in a LIDAR system is related to the spectral reflectance of the target material and...

  20. Riparian soil development linked to forest succession above and below dams along the Elwha River, Washington, USA

    Science.gov (United States)

    Perry, Laura G; Shafroth, Patrick B.; Perakis, Steven

    2017-01-01

    Riparian forest soils can be highly dynamic, due to frequent fluvial disturbance, erosion, and sediment deposition, but effects of dams on riparian soils are poorly understood. We examined soils along toposequences within three river segments located upstream, between, and downstream of two dams on the Elwha River to evaluate relationships between riparian soil development and forest age, succession, and channel proximity, explore dam effects on riparian soils, and provide a baseline for the largest dam removal in history. We found that older, later-successional forests and geomorphic surfaces contained soils with finer texture and greater depth to cobble, supporting greater forest floor mass, mineral soil nutrient levels, and cation exchange. Forest stand age was a better predictor than channel proximity for many soil characteristics, though elevation and distance from the channel were often also important, highlighting how complex interactions between fluvial disturbance, sediment deposition, and biotic retention regulate soil development in this ecosystem. Soils between the dams, and to a lesser extent below the lower dam, had finer textures and higher mineral soil carbon, nitrogen, and cation exchange than above the dams. These results suggested that decreased fluvial disturbance below the dams, due to reduced sediment supply and channel stabilization, accelerated soil development. In addition, reduced sediment supply below the dams may have decreased soil phosphorus. Soil δ15N suggested that salmon exclusion by the dams had no discernable effect on nitrogen inputs to upstream soils. Recent dam removal may alter riparian soils further, with ongoing implications for riparian ecosystems.

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