The potential of carbon and nitrogen isotopes to conservatively discriminate between subsoil sediment sources

NASA Astrophysics Data System (ADS)

Laceby, J. Patrick; Olley, Jon

2013-04-01

Moreton Bay, in South East Queensland, Australia, is a Ramsar wetland of international significance. A decline of the bay's ecosystem health has been primarily attributed to sediments and nutrients from catchment sources. Sediment budgets for three catchments indicated gully erosion dominates the supply of sediment in Knapp Creek and the Upper Bremer River whereas erosion from cultivated soils is the primary sediment source in Blackfellow Creek. Sediment tracing with fallout-radionuclides confirmed subsoil erosion processes dominate the supply of sediment in Knapp Creek and the Upper Bremer River whereas in Blackfellow Creek cultivated and subsoil sources contribute >90% of sediments. Other sediment properties are required to determine the relative sediment contributions of channel bank, gully and cultivated sources in these catchments. The potential of total organic carbon (TOC), total nitrogen (TN), and carbon and nitrogen stable isotopes (δ13C, δ15N) to conservatively discriminate between subsoil sediment sources is presented. The conservativeness of these sediment properties was examined through evaluating particle size variations in depth core soil samples and investigating whether they remain constant in source soils over two sampling occasions. Varying conservative behavior and source discrimination was observed. TN in the

Integrated Systems Mitigate Land Degradation and Improve Agricultural System Sustainability

NASA Astrophysics Data System (ADS)

Landblom, Douglas; Senturklu, Songul; Cihacek, Larry; Brevik, Eric

2017-04-01

Rain-fed agricultural production supported by exogenous inputs is not sustainable because a continuous influx of expensive inputs (fertilizer, chemicals, fossil fuel, labor, tillage, and other) is required. Alternatives to traditional management allow natural occurring dynamic soil processes to provide the necessary microbial activity that supports nutrient cycling in balance with nature. Research designed to investigate the potential for integrated systems to replace expensive inputs has shown that healthy soils rich in soil organic matter (SOM) are the foundation upon which microbial nutrient cycling can reduce and eventually replace expensive fertilizer. No-till seed placement technology effectively replaces multiple-pass cultivation conserving stored soil water in semi-arid farming systems. In multi-crop rotations, cool- and warm-season crops are grown in sequence to meet goals of the integrated farming and ranching system, and each crop in the rotation complements the subsequent crop by supplying a continuous flow of essential SOM for soil nutrient cycling. Grazing animals serve an essential role in the system's sustainability as non-mechanized animal harvesters that reduce fossil fuel consumption and labor, and animal waste contributes soil nutrients to the system. Integrated systems' complementarity has contributed to greater soil nutrient cycling and crop yields, fertilizer reduction or elimination, greater yearling steer grazing net return, reduced cow wintering costs grazing crop residues, increased wildlife sightings, and reduced environmental footprint. Therefore, integrating crop and animal systems can reverse soil quality decline and adopting non-traditional procedures has resulted in a wider array of opportunities for sustainable agriculture and profitability.

User-inspired Research Quantifies How Floodplain Restoration Paired With Cover Crops Reduces Nutrient Export From an Agricultural Catchment Translating to Conservation Success in the Midwestern Cornbelt.

NASA Astrophysics Data System (ADS)

Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Mahl, U. H.; Royer, T. V.

2017-12-01

The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter agricultural streams, which degrades both local and downstream water quality. We are quantifying the nutrient reduction benefits of two conservation practices implemented at the catchment scale. In partnership with The Nature Conservancy, in a small Indiana catchment, we have quantified how 600m of floodplain restoration (i.e., a two-stage ditch) increased nitrate-N removal via denitrification and reduced sediment export, but impacts on stream nutrient concentrations were negligible due to very high catchment loading relative to the short implementation reach. Requests from state and federal partners led to development and parameterization of a new two-stage ditch module in the SWAT model to determine the potential catchment-scale benefits when implementation lengths were extended. More recently, in partnership with state SWCD managers, we have added a landscape practice to quantify how winter cover crops reduce nutrient loss from fields, sampling year-round nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel. Nitrate-N and dissolved P fluxes were significantly lower in tiles draining fields with cover crops compared to those without. At the urging of farmers and federal NRCS partners, we also linked tile drain nutrient reductions to changes in soil chemistry. Both soil nitrate-N and dissolved P were lower in cover cropped fields, and we found significant correlations between soil and tile drain nutrients, which may encourage future adoption of the conservation practice as soil health benefits appeal to farmers. As biogeochemists, this research has provided valuable insights on how floodplains and land cover change can alter patterns of catchment-scale nutrient export. The translation of successful soil and water quality outcomes through this significant regional demonstration project make it a potentially powerful agent of change for advancing conservation success.

Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

NASA Astrophysics Data System (ADS)

Williams, Mark R.; Livingston, Stanley J.; Penn, Chad J.; Smith, Douglas R.; King, Kevin W.; Huang, Chi-hua

2018-04-01

Understanding the processes controlling nutrient delivery in headwater agricultural watersheds is essential for predicting and mitigating eutrophication and harmful algal blooms in receiving surface waters. The objective of this study was to elucidate nutrient transport pathways and examine key components driving nutrient delivery processes during storm events in four nested agricultural watersheds (298-19,341 ha) in the western Lake Erie basin with poorly drained soils and an extensive artificial drainage network typical of the Midwestern U.S. Concentration-discharge hysteresis patterns of nitrate-nitrogen (NO3-N), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP) occurring during 47 storm events over a 6 year period (2004-2009) were evaluated. An assessment of the factors producing nutrient hysteresis was completed following a factor analysis on a suite of measured environmental variables representing the fluvial and wider watershed conditions prior to, and during the monitored storm events. Results showed the artificial drainage network (i.e., surface tile inlets and subsurface tile drains) in these watersheds was the primary flow pathway for nutrient delivery to streams, but nutrient behavior and export during storm events was regulated by the flow paths to and the intensity of the drainage network, the availability of nutrients, and the relative contributions of upland and in-stream nutrient sources. Potential sources and flow pathways for transport varied among NO3-N, PP, and DRP with results underscoring the challenge of mitigating nutrient loss in these watersheds. Conservation practices addressing both nutrient management and hydrologic connectivity will likely be required to decrease nutrient loss in artificially drained landscapes.

Quantifying the effects of conservation practices on soil, water, and nutrients in the Loess Mesa Ravine Region of the Loess Plateau, China.

PubMed

Xu, Xiang-Zhou; Li, Mei-Juan; Liu, Bin; Kuang, Shang-Fu; Xu, Shi-Guo

2012-05-01

A large number of soil and water conservation programs have been implemented on the Loess Plateau of China since the 1950s. To comprehensively assess the merits and demerits of the conservation practices is of great importance in further supervising the conservation strategy for the Loess Plateau. This study calculates the impact factors of conservation practices on soil, water, and nutrients during the period 1954-2004 in the Nanxiaohegou Catchment, a representative catchment in the Loess Mesa Ravine Region of the Loess Plateau, China. Brief conclusions could be drawn as follows: (1) Soil erosion and nutrient loss had been greatly mitigated through various conservation practices. About half of the total transported water and 94.8 % of the total transported soil and nutrients, had been locally retained in the selected catchment. The soil retained from small watersheds do not only form large-scale fertile farmland but also safeguard the Yellow River against overflow. (2) Check dam was the most appropriate conservation practice on the Loess Plateau. In the selected catchment, more than 90 % of the retained soil and water were accomplished by the dam farmland, although the dam farmland occupied only 2.3 % of the total area of all conservation measures. Retention abilities of the characteristic conservation practices were in the following order: dam farmland > terrace farmland > forest land and grassland. (3) The conservation practices were more powerful in retaining sediment than in reducing runoff from the Loess Plateau, and the negative effects of the conservation practices on reducing water to the Yellow River were relatively slight.

Conserved Transcriptional Responses to Nutrient Stress in Bloom-Forming Algae

PubMed Central

Harke, Matthew J.; Juhl, Andrew R.; Haley, Sheean T.; Alexander, Harriet; Dyhrman, Sonya T.

2017-01-01

The concentration and composition of bioavailable nitrogen (N) and phosphorus (P) in the upper ocean shape eukaryotic phytoplankton communities and influence their physiological responses. Phytoplankton are known to exhibit similar physiological responses to limiting N and P conditions such as decreased growth rates, chlorosis, and increased assimilation of N and P. Are these responses similar at the molecular level across multiple species? To interrogate this question, five species from biogeochemically important, bloom-forming taxa (Bacillariophyta, Dinophyta, and Haptophyta) were grown under similar low N, low P, and replete nutrient conditions to identify transcriptional patterns and associated changes in biochemical pools related to N and P stress. Metabolic profiles, revealed through the transcriptomes of these taxa, clustered together based on species rather than nutrient stressor, suggesting that the global metabolic response to nutrient stresses was largely, but not exclusively, species-specific. Nutrient stress led to few transcriptional changes in the two dinoflagellates, consistent with other research. An orthologous group analysis examined functionally conserved (i.e., similarly changed) responses to nutrient stress and therefore focused on the diatom and haptophytes. Most conserved ortholog changes were specific to a single nutrient treatment, but a small number of orthologs were similarly changed under both N and P stress in 2 or more species. Many of these orthologs were related to photosynthesis and may represent generalized stress responses. A greater number of orthologs were conserved across more than one species under low P compared to low N. Screening the conserved orthologs for functions related to N and P metabolism revealed increased relative abundance of orthologs for nitrate, nitrite, ammonium, and amino acid transporters under N stress, and increased relative abundance of orthologs related to acquisition of inorganic and organic P substrates under P stress. Although the global transcriptional responses were dominated by species-specific changes, the analysis of conserved responses revealed functional similarities in resource acquisition pathways among different phytoplankton taxa. This overlap in nutrient stress responses observed among species may be useful for tracking the physiological ecology of phytoplankton field populations. PMID:28769884

Nutrient elements in large Chinese estuaries

NASA Astrophysics Data System (ADS)

Zhang, Jing

1996-07-01

Based on comprehensive observations since 1983, this study summarizes major features of nutrient elements (nitrogen, phosphorus and silicon) in large Chinese river/estuary systems. Elevated nutrient element levels were observed in Chinese rivers, when compared to large and less disturbed aquatic systems (e.g. the Amazon, Zaire and Orinoco). Data from this study are similar to those obtained from the polluted and/or eutrophic rivers in Europe and North America (e.g. the Rhóne and Loire). Nutrient elements may have either conservative or active distributions, or both, in the mixing zone, depending on the element and the estuary. For example, non-conservative behaviors were observed in the upper estuary, where nutrient elements may be remobilized due to the strong desorption and variations of the fresh water end-member, but conservative distributions were found afterwards in the lower estuary. Outside the riverine effluent plumes, nutrient elements may be depleted in surface waters relative to elevated bioproduction, whereas the regeneration with respect to decomposition of organic material and/or nitrification/denitrification offshore, may sustain high levels of nutrient elements in near-bottom waters. Laboratory experiment data generally compares well with field observations. The high fluxes and area] yields of nutrient elements from large Chinese rivers, indicate the extensive use of chemical fertilizers and domestic waste drainage over watersheds in China.

Integrated watershed management for saturation excess generated runoff, erosion and nutrient control

USDA-ARS?s Scientific Manuscript database

Understanding the basic hydrology and erosion is vital for effective management and utilization of water resources and soil conservation planning. An important question for judging effectiveness of soil and water conservation practices is whether runoff erosion and nutrient loss is affected by infil...

Soil nutrient availability and reproductive effort drive patterns in nutrient resorption in Pentachlethra macroloba

Treesearch

K. L. Tully; Tana Wood; A. M. Schwantes; D. Lawrence

2013-01-01

The removal of nutrients from senescing tissues, nutrient resorption, is a key strategy for conserving nutrients in plants. However, our understanding of what drives patterns of nutrient resorption in tropical trees is limited. We examined the effects of nutrient sources (stand-level and tree-level soil fertility) and sinks (reproductive effort) on nitrogen (N) and...

Agricultural conservation planning framework: 1. Developing multi-practice watershed planning scenarios and assessing nutrient reduction potential

USDA-ARS?s Scientific Manuscript database

We show that spatial data on soils, land use, and high-resolution topography, combined with knowledge of conservation practice effectiveness, can be leveraged to identify and assess alternatives to reduce nutrient discharge from small (HUC12) agricultural watersheds. Databases comprising soil attrib...

Thinking outside of the Lake: Can controls on nutrient inputs into Lake Erie benefit stream conservation in its watershed?

USDA-ARS?s Scientific Manuscript database

Investment in agricultural conservation practices (CPs) to address Lake Erie's re-eutrophication may offer benefits that extend beyond the lake, such as improved habitat conditions for fish communities throughout the watershed. If such conditions are not explicitly considered in Lake Erie nutrient ...

Least-cost control of agricultural nutrient contributions to the Gulf of Mexico hypoxic zone.

PubMed

Rabotyagov, Sergey; Campbell, Todd; Jha, Manoj; Gassman, Philip W; Arnold, Jeffrey; Kurkalova, Lyubov; Secchi, Silvia; Feng, Hongli; Kling, Catherine L

2010-09-01

In 2008, the hypoxic zone in the Gulf of Mexico, measuring 20 720 km2, was one of the two largest reported since measurement of the zone began in 1985. The extent of the hypoxic zone is related to nitrogen and phosphorous loadings originating on agricultural fields in the upper Midwest. This study combines the tools of evolutionary computation with a water quality model and cost data to develop a trade-off frontier for the Upper Mississippi River Basin specifying the least cost of achieving nutrient reductions and the location of the agricultural conservation practices needed. The frontier allows policymakers and stakeholders to explicitly see the trade-offs between cost and nutrient reductions. For example, the cost of reducing annual nitrate-N loadings by 30% is estimated to be US$1.4 billion/year, with a concomitant 36% reduction in P and the cost of reducing annual P loadings by 30% is estimated to be US$370 million/year, with a concomitant 9% reduction in nitrate-N.

Comparative analysis of phytochemicals and nutrient availability in two contrasting cultivars of sweet potato (Ipomoea batatas L.).

PubMed

Shekhar, Shubhendu; Mishra, Divya; Buragohain, Alak Kumar; Chakraborty, Subhra; Chakraborty, Niranjan

2015-04-15

Sweet potato ranks as the world's seventh most important food crop, and has major contribution to energy and phytochemical source of nutrition. To unravel the molecular basis for differential nutrient availability, and to exploit the natural genetic variation(s) of sweet potato, a series of physiochemical and proteomics experiment was conducted using two contrasting cultivars, an orange-fleshed sweet potato (OFSP) and a white-fleshed sweet potato (WFSP). Phytochemical screening revealed high percentage of carbohydrate, reducing sugar and phenolics in WFSP, whereas OFSP showed increased levels of total protein, flavonoids, anthocyanins, and carotenoids. The rate of starch and cellulose degradation was found to be less in OFSP during storage, indicating tight regulation of gene(s) responsible for starch-degradation. Comparative proteomics displayed a cultivar-dependent expression of proteins along with evolutionarily conserved proteins. These results suggest that cultivar-specific expression of proteins and/or their interacting partners might play a crucial role for nutrient acquisition in sweet potato. Copyright © 2014 Elsevier Ltd. All rights reserved.

Relating management practices and nutrient export in agricultural watersheds of the United States

USGS Publications Warehouse

Sprague, Lori A.; Gronberg, Jo Ann M.

2012-01-01

Relations between riverine export (load) of total nitrogen (N) and total phosphorus (P) from 133 large agricultural watersheds in the United States and factors affecting nutrient transport were evaluated using empirical regression models. After controlling for anthropogenic inputs and other landscape factors affecting nutrient transport-such as runoff, precipitation, slope, number of reservoirs, irrigated area, and area with subsurface tile drains-the relations between export and the area in the Conservation Reserve Program (CRP) (N) and conservation tillage (P) were positive. Additional interaction terms indicated that the relations between export and the area in conservation tillage (N) and the CRP (P) progressed from being clearly positive when soil erodibility was low or moderate, to being close to zero when soil erodibility was higher, to possibly being slightly negative only at the 90th to 95th percentile of soil erodibility values. Possible explanations for the increase in nutrient export with increased area in management practices include greater transport of soluble nutrients from areas in conservation tillage; lagged response of stream quality to implementation of management practices because of nitrogen transport in groundwater, time for vegetative cover to mature, and/or prior accumulation of P in soils; or limitations in the management practice and stream monitoring data sets. If lags are occurring, current nutrient export from agricultural watersheds may still be reflecting the influence of agricultural land-use practices that were in place before the implementation of these management practices.

Maintaining adequate nutrient supply - Principles, decision-support tools, and best management practices [Chapter 6

Treesearch

Robert B. Harrison; Douglas A. Maguire; Deborah Page-Dumroese

2011-01-01

Maintaining adequate nutrient supply to maintain or enhance tree vigor and forest growth requires conservation of topsoil and soil organic matter. Sometimes nutrient amendments are also required to supplement inherent nutrient-pool limitations or replenish nutrients removed in harvested material. The goal is to maintain the productive potential of the soil and, when...

A VSA-based strategy for placing conservation buffers in agricultural watersheds.

PubMed

Qiu, Zeyuan

2003-09-01

Conservation buffers have the potential to reduce agricultural nonpoint source pollution and improve terrestrial wildlife habitat, landscape biodiversity, flood control, recreation, and aesthetics. Conservation buffers, streamside areas and riparian wetlands are being used or have been proposed to control agricultural nonpoint source pollution. This paper proposes an innovative strategy for placing conservation buffers based on the able source area (VSA) hydrology. VSAs are small, variable but predictable portion of a watershed that regularly contributes to runoff generation. The VSA-based strategy involves the following three steps: first, identifying VSAs in landscapes based on natural characteristics such as hydrology, land use/cover, topography and soils; second, targeting areas within VSAs for conservation buffers; third, refining the size and location of conservation buffers based on other factors such as weather, environmental objectives, available funding and other best management practices. Building conservation buffers in VSAs allows agricultural runoff to more uniformly enter buffers and stay there longer, which increases the buffer's capacity to remove sediments and nutrients. A field-scale example is presented to demonstrate the effectiveness and cost-effectiveness of the within-VSA conservation buffer scenario relative to a typical edge-of-field buffer scenario. The results enhance the understanding of hydrological processes and interactions between agricultural lands and conservation buffers in agricultural landscapes, and provide practical guidance for land resource managers and conservationists who use conservation buffers to improve water quality and amenity values of agricultural landscape.

Nutrient Concentrations and Stable Isotopes of Runoff from a Midwest Tile-Drained Corn Field

NASA Astrophysics Data System (ADS)

Wilkins, B. P.; Woo, D.; Li, J.; Michalski, G. M.; Kumar, P.; Conroy, J. L.; Keefer, D. A.; Keefer, L. L.; Hodson, T. O.

2017-12-01

Tile drains are a common crop drainage device used in Midwest agroecosystems. While efficient at drainage, the tiles provide a quick path for nutrient runoff, reducing the time available for microbes to use nutrients (e.g., NO3- and PO43-) and reduce export to riverine systems. Thus, understanding the effects of tile drains on nutrient runoff is critical to achieve nutrient reduction goals. Here we present isotopic and concentration data collected from tile drain runoff of a corn field located near Monticello, IL. Tile flow samples were measured for anion concentrations and stable isotopes of H2O and NO3-, while precipitation was measured for dual isotopes of H2O. Results demonstrate early tile flow from rain events have a low Cl- concentration (<20ppm) with water isotopic values reflecting precipitation, indicating preferential flow (>60% contribution) in the beginning of the hydrograph. As flow continues H2O isotopic values reflect pre-event water (ground and soil water), and Cl- concentrations increase representing a greater influence by matrix flow (60-90% contribution). Nitrate concentrations change dramatically, especially during the growing season, and do not follow a similar trend as the conservative Cl-, often decreasing days before, which represents missing nitrate in the upper surface portion of the soil. Nitrate isotopic data shows significant changes in 15N (4‰) and 18O (4‰) during individual hydrological events, representing that in addition to plant uptake and leaching, considerate NO3- is lost through denitrification. It is notable, that throughout the season d15N and d18O of nitrate change significantly representing that seasonally, substantial denitrification occurs.

Lake Nutrient Responses to Integrated Conservation Practices in an Agricultural Watershed.

PubMed

Lizotte, Richard E; Yasarer, Lindsey M W; Locke, Martin A; Bingner, Ronald L; Knight, Scott S

2017-03-01

Watershed-scale management efforts to reduce nutrient loads and improve the conservation of lakes in agricultural watersheds require effective integration of a variety of agricultural conservation best management practices (BMPs). This paper documents watershed-scale assessments of the influence of multiple integrated BMPs on oxbow lake nutrient concentrations in a 625-ha watershed of intensive row-crop agricultural activity during a 14-yr monitoring period (1996-2009). A suite of BMPs within fields and at field edges throughout the watershed and enrollment of 87 ha into the Conservation Reserve Program (CRP) were implemented from 1995 to 2006. Total phosphorus (TP), soluble reactive phosphorus (SRP), ammonium, and nitrate were measured approximately biweekly from 1996 to 2009, and total nitrogen (TN) was measured from 2001 to 2009. Decreases in several lake nutrient concentrations occurred after BMP implementation. Reductions in TP lake concentrations were associated with vegetative buffers and rainfall. No consistent patterns of changes in TN or SRP lake concentrations were observed. Reductions in ammonium lake concentrations were associated with conservation tillage and CRP. Reductions in nitrate lake concentrations were associated with vegetative buffers. Watershed simulations conducted with the AnnAGNPS (Annualized Agricultural Non-Point Source) model with and without BMPs also show a clear reduction in TN and TP loads to the lake after the implementation of BMPs. These results provide direct evidence of how watershed-wide BMPs assist in reducing nutrient loading in aquatic ecosystems and promote a more viable and sustainable lake ecosystem. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Conservation of soil, water and nutrients in surface runoff using riparian plant species.

PubMed

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.

Nutrient management

USDA-ARS?s Scientific Manuscript database

Nutrient management has been defined as “the science and art directed to link soil, crop, weather and hydrologic factors with cultural, irrigation and soil and water conservation practices to achieve the goals of optimizing nutrient use efficiency, yields, crop quality, and economic returns, while r...

Regional effects of agricultural conservation practices on nutrient transport in the Upper Mississippi River Basin

USGS Publications Warehouse

Garcia, Ana Maria.; Alexander, Richard B.; Arnold, Jeffrey G.; Norfleet, Lee; White, Michael J.; Robertson, Dale M.; Schwarz, Gregory E.

2016-01-01

Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical U.S. Geological Survey water-quality model SPARROW to investigate whether spatial differences in conservation intensity were statistically correlated with variations in nutrient loads. In contrast to other forms of water quality data analysis, the application of SPARROW controls for confounding factors such as hydrologic variability, multiple sources and environmental processes. A measure of conservation intensity was derived from the USDA-CEAP regional assessment of the Upper Mississippi River and used as an explanatory variable in a model of the Upper Midwest. The spatial pattern of conservation intensity was negatively correlated (p = 0.003) with the total nitrogen loads in streams in the basin. Total phosphorus loads were weakly negatively correlated with conservation (p = 0.25). Regional nitrogen reductions were estimated to range from 5 to 34% and phosphorus reductions from 1 to 10% in major river basins of the Upper Mississippi region. The statistical associations between conservation and nutrient loads are consistent with hydrological and biogeochemical processes such as denitrification. The results provide empirical evidence at the regional scale that conservation practices have had a larger statistically detectable effect on nitrogen than on phosphorus loadings in streams and rivers of the Upper Mississippi Basin.

Regional Effects of Agricultural Conservation Practices on Nutrient Transport in the Upper Mississippi River Basin.

PubMed

García, Ana María; Alexander, Richard B; Arnold, Jeffrey G; Norfleet, Lee; White, Michael J; Robertson, Dale M; Schwarz, Gregory

2016-07-05

Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical U.S. Geological Survey water-quality model SPARROW to investigate whether spatial differences in conservation intensity were statistically correlated with variations in nutrient loads. In contrast to other forms of water quality data analysis, the application of SPARROW controls for confounding factors such as hydrologic variability, multiple sources and environmental processes. A measure of conservation intensity was derived from the USDA-CEAP regional assessment of the Upper Mississippi River and used as an explanatory variable in a model of the Upper Midwest. The spatial pattern of conservation intensity was negatively correlated (p = 0.003) with the total nitrogen loads in streams in the basin. Total phosphorus loads were weakly negatively correlated with conservation (p = 0.25). Regional nitrogen reductions were estimated to range from 5 to 34% and phosphorus reductions from 1 to 10% in major river basins of the Upper Mississippi region. The statistical associations between conservation and nutrient loads are consistent with hydrological and biogeochemical processes such as denitrification. The results provide empirical evidence at the regional scale that conservation practices have had a larger statistically detectable effect on nitrogen than on phosphorus loadings in streams and rivers of the Upper Mississippi Basin.

Tracing suspended sediment sources in the Upper Sangamon River Basin using conservative and non-conservative tracers

NASA Astrophysics Data System (ADS)

Yu, M.; Rhoads, B. L.; Stumpf, A.

2015-12-01

As the awareness of water pollution, eutrophication and other water related environmental concerns grows, the significance of sediment in the transport of nutrients and contaminants from agricultural areas to streams has received increasing attention. Both the physical and geochemical properties of suspended sediment are strongly controlled by sediment sources. Thus, tracing sources of suspended sediment in watersheds is important for the design of management practices to reduce sediment loads and contributions of sediment-adsorbed nutrients from agricultural areas to streams. However, the contributions of different sediment sources to suspended sediment loads within intensively managed watersheds in the Midwest still remain insufficiently explored. This study aims to assess the provenance of suspended sediment and the relation between channel morphology and production of suspended sediment in the Upper Sangamon River Basin, Illinois, USA. The 3,690-km2 Upper Sangamon River Basin is characterized by low-relief, agricultural lands dominated by row-crop agriculture. Sediment source samples were collected in the Saybrook from five potential sources: farmland, forests, floodplains, river banks, and grasslands. Event-based and accumulated suspended sediment samples were collected by ISCO automatic pump samplers and in situ suspended sediment samplers and from the stream at watershed outlet. A quantitative geochemical fingerprinting technique, combining statistically verified multicomponent signatures and an un-mixing model, was employed to estimate the relative contributions of sediment from five potential sources to the suspended sediment loads. Organic matter content, trace elements, and radionuclides from soil samples were used as potential tracers. Our preliminary results indicate that the majority of suspended sediment is derived from floodplains in the downstream portions of the watersheds, while only minor amounts of suspended sediment are derived from upland areas and banks. These results suggest that floodplain erosion during high flow events contributes to the suspended sediment.

Characterization and Placement of Wetlands for Integrated ...

EPA Pesticide Factsheets

Constructed wetlands have been recognized as an efficient and cost-effective conservation practice to protect water quality through reducing the transport of sediments and nutrients from upstream croplands to downstream water bodies. The challenge resides in targeting the strategic location of wetlands within agricultural watersheds to maximize the reduction in nutrient loads while minimizing their impact on crop production. Furthermore, agricultural watersheds involve complex interrelated processes requiring a systems approach to evaluate the inherent relationships between wetlands and multiple sediment/nutrient sources (sheet, rill, ephemeral gully, channels) and other conservation practices (filter strips). This study describes new capabilities of the USDA’s Annualized Agricultural Non-Point Source pollutant loading model, AnnAGNPS. A developed AnnAGNPS GIS-based wetland component, AgWet, is introduced to identify potential sites and characterize individual artificial or natural wetlands at a watershed scale. AgWet provides a simplified, semi-automated, and spatially distributed approach to quantitatively evaluate wetlands as potential conservation management alternatives. AgWet is integrated with other AnnAGNPS components providing seamless capabilities of estimating the potential sediment/nutrient reduction of individual wetlands. This technology provides conservationists the capability for improved management of watershed systems and support for nutrient

Modeling Mitigation Activities in North Carolina Watersheds

NASA Astrophysics Data System (ADS)

Garcia, A. M.

2017-12-01

Nutrient enrichment and excessive sediment loadings have contributed to the degradation of rivers, lakes and estuaries in North Carolina. The North Carolina Department of Environmental Quality (NCDEQ) has implemented several basin-wide nutrient and sediment management strategies, yet gaps remain in understanding the impact of these strategies given the complexities in quantifying the processes that govern the transport of nutrient and sediment. In particular, improved assessment of the status of nutrient and sediment loadings to lakes and estuaries throughout the state is needed, including characterizing their sources and describing the relative contributions of different areas. The NCDEQ Division of Mitigation Services (DMS) uses watershed planning to identify and prioritize the best locations to implement stream, wetland, and riparian-buffer restoration to improve water quality. To support better decision-making for watershed restoration activities we are developing a SPARROW (SPAtially Referenced Regressions On Watershed attributes) model framework specifically for North Carolina. The SPARROW analysis (developed by the U.S. Geological Survey) relates water-quality monitoring data to better understand the effects of human activities and natural processes on surface-water quality. The core of the model consists of using a nonlinear-regression equation to describe the non-conservative transport of contaminants from point and nonpoint sources on land to rivers, lakes and estuaries through the stream and river network. In this presentation, preliminary total Nitrogen, total Phosphorus, and Total Suspended Solids (TSS) NC-SPARROW models are described that illustrate the SPARROW modeling framework incorporating specific restoration datasets and activity metrics, such as extent of riparian buffer and easements.

Summer nitrogenous nutrient transport and its fate in the Taiwan Strait: A coupled physical-biological modeling approach

NASA Astrophysics Data System (ADS)

Wang, Jia; Hong, Huasheng; Jiang, Yuwu; Chai, Fei; Yan, Xiao-Hai

2013-09-01

In order to understand the fate of nutrients in the Taiwan Strait during summer, we built a coupled physical-biological numerical ocean model, which can capture the basic hydrographic and biological features within the strait. The nutrient that we chose to model is dissolved inorganic nitrogen (DIN). The model includes individual reservoirs for nitrate (NO3) and ammonium (NH4). Both the observational evidence and model results show that NO3 in the strait originates primarily from the upwelling subsurface water in the northern South China Sea (SCS) that enters the strait via the eastern and western routes separated by the Taiwan Bank. The coupled physical and biological effects on the NO3 transport at these two routes are highlighted in the study. For the western route, the shallow topography and the coastal upwelling intensify the biological uptake of NO3 in the whole water column. Consequently, the nitrogenous contribution by this route is mainly in form of the particulate organic nitrogen (PON). In contrast, NO3 is transported conservatively below the nitricline at the deep eastern route, contributing the whole NO3 supply in the TWS. The model estimates the fluxes of DIN and PON into the TWS, from the northern SCS, are 1.8 and 4 kmol s-1, respectively. Over half (˜1 kmol s-1) of the DIN is synthesized into PON by the phytoplankton in the strait. Overall, this study estimates the physical and biological effects on the nutrient transport in the TWS during summer.

Interannual variability in dissolved inorganic nutrients in northern San Francisco Bay estuary

USGS Publications Warehouse

Peterson, D.H.; Smith, R.E.; Hager, S.W.; Harmon, D.D.; Herndon, R.E.; Schemel, L.E.

1985-01-01

Nearly two decades of seasonal dissolved inorganic nutrient-salinity distributions in northern San Francisco Bay estuary (1960-1980) illustrate interannual variations in effects of river flow (a nutrient source) and phytoplankton productivity (a nutrient sink). During winter, nutrient sources dominate the nutrient-salinity distribution patterns (nutrients are at or exceed conservative mixing concentrations). During summer, however, the sources and sinks are in close competition. In summers of wet years, the effects of increased river flow often dominate the nutrient distributions (nutrients are at or less than conservative mixing concentrations), whereas in summers of dry years, phytoplankton productivity dominates (the very dry years 1976-1977 were an exception for reasons not yet clearly known). Such source/sink effects also vary with chemical species. During summer the control of phytoplankton on nutrient distributions is apparently strongest for ammonium, less so for nitrate and silica, and is the least for phosphate. Furthermore, the strength of the silica sink (diatom productivity) is at a maximum at intermediate river flows. This relation, which is in agreement with other studies based on phytoplankton abundance and enumeration, is significant to the extent that diatoms are an important food source for herbivores. The balance or lack of balance between nutrient sources and sinks varies from one estuary to another just as it can from one year to another within the same estuary. At one extreme, in some estuaries river flow dominates the estuarine dissolved inorganic nutrient distributions throughout most of the year. At the other extreme, phytoplankton productivity dominates. In northern San Francisco Bay, for example, the phytoplankton nutrient sink is not as strong as in less turbid estuaries. In this estuary, however, river effects, which produce or are associated with near-conservative nutrient distributions, are strong even at flows less than mean-annual flow. Thus, northern San Francisco Bay appears to be an estuary in between the two extremes and is shifted closer to one extreme or the other depending on interannual variations in river flow. ?? 1985 Dr W. Junk Publishers.

NUTRIENT TRANSPORT DURING BIOREMEDIATION OF CONTAMINATED BEACHES: EVALUATION WITH LITHIUM AS A CONSERVATIVE TRACER

EPA Science Inventory

Bioremediation of oil-contaminated beaches typically involves fertilization with nutrients that are thought to limit the growth rate of hydrocarbon-degrading bacteria. Much of the available technology involves application of fertilizers that release nutrients in a water-soluble ...

Watershed-Scale Cover Crops Reduce Nutrient Export From Agricultural Landscapes.

NASA Astrophysics Data System (ADS)

Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Trentman, M. T.; Royer, T. V.; Prior, K.

2016-12-01

The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter Midwestern agricultural streams, which degrades both local and downstream water quality, resulting in algal blooms and subsequent hypoxic "dead zones" far from the nutrient source. We are quantifying the benefits of watershed-scale conservation practices that may reduce nutrient runoff from adjacent farm fields. Specifically, research is lacking on whether the planting of winter cover crops in watersheds currently dominated by row-crop agriculture can significantly reduce nutrient inputs to adjacent streams. Since 2013, farmers have planted cover crops on 70% of croppable acres in the Shatto Ditch Watershed (IN), and "saturation level" implementation of this conservation practice has been sustained for 3 years. Every 14 days, we have quantified nutrient loss from fields by sampling nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel throughout the watershed. Cover crops improved stream water quality by reducing dissolved inorganic nutrients exported downstream; nitrate-N and DRP concentrations and fluxes were significantly lower in tiles draining fields with cover crops compared to those without. Annual watershed nutrient export also decreased, and reductions in N and P loss ( 30-40%) exceeded what we expected based on only a 6-10% reduction in runoff due to increased watershed water holding capacity. We are also exploring the processes responsible for increased nutrient retention, where they are occurring (terrestrial vs. aquatic) and when (baseflow vs. storms). For example, whole-stream metabolism also responded to cover crop planting, showing reduced variation in primary production and respiration in years after watershed-scale planting of cover crops. In summary, widespread land cover change, through cover crop planting, can significantly reduce annual watershed-scale nutrient export. Moreover, successful outcomes highlighted through demonstration projects may facilitate widespread adoption, making them powerful agents of change for advancing conservation success.

Landscape hydrology and scaling of nitrate 15N and 18O isotope composition in a semi-arid agroecosystem

NASA Astrophysics Data System (ADS)

Kelley, C. J.; Martin, R. A.; Keller, C. K.; Orr, C. H.; Huggins, D. R.; Evans, R. D.

2014-12-01

Understanding how pore- to hillslope-scale processes combine to control nutrient export at larger scales is a fundamental challenge in today's agroecosystems as the carbon and contamination footprints of production agriculture come under increasing scrutiny. At the Cook Agronomy Farm (CAF) Long-Term Agricultural Research (LTAR) station near Pullman, WA we are using in-field observations to track how local-scale hydrological routing and biogeochemical processing interact to control landscape-scale water and nutrient exports. Previous research at the CAF has shown that conservative tracers and reactive nutrient quantities (NO3-,and DOC concentrations, DOM quality) in landscape-scale drainage can be explained by straightforward mixing of waters from variably contributing areas. Nitrate stable isotope composition in subsurface drain effluent indicate that most leached nitrate originates from reduced nitrogen fertilizer applied to the CAF in the autumn, which undergoes nitrification and subsequent leaching. This occurs over a timespan of weeks to months. However, water samples from contributing areas exhibit nitrate d15N and d18O significantly greater than subsurface drain effluent at all locations, and time-series consistent with the occurrence of denitrification at some locations. Possible explanations include pore-scale processing of nitrogen that does not affect the other tracers (like EC, DOM quality, and DOC concentration), and landscape-scale transport pathways that bypass our field instruments. Through this work we are contributing to a broader understand of how global change and local factors and management practices interact to affect the fate of fertilizer N, which is a cross-cutting research theme of the national LTAR network.

Trait-abundance relation in response to nutrient addition in a Tibetan alpine meadow: The importance of species trade-off in resource conservation and acquisition.

PubMed

Liu, Huiying; Li, Ying; Ren, Fei; Lin, Li; Zhu, Wenyan; He, Jin-Sheng; Niu, Kechang

2017-12-01

In competition-dominated communities, traits promoting resource conservation and competitive ability are expected to have an important influence on species relative abundance (SRA). Yet, few studies have tested the trait-abundance relations in the line of species trade-off in resource conservation versus acquisition, indicating by multiple traits coordination. We measured SRA and key functional traits involving leaf economic spectrum (SLA, specific leaf area; LDMC, leaf dry matter content; LCC, leaf carbon concentration; LNC, leaf nitrogen concentration; LPC, leaf phosphorus concentration; Hs, mature height) for ten common species in all plots subjected to addition of nitrogen fertilizer (N), phosphorus fertilizer (P), or both of them (NP) in a Tibetan alpine meadow. We test whether SRA is positively related with traits promoting plant resource conservation, while negatively correlated with traits promoting plant growth and resource acquisition. We found that species were primarily differentiated along a trade-off axis involving traits promoting nutrient acquisition and fast growth (e.g., LPC and SLA) versus traits promoting resource conservation and competition ability (e.g., large LDMC). We further found that SRA was positively correlated with plant height, LDMC, and LCC, but negatively associated with SLA and leaf nutrient concentration irrespective of fertilization. A stronger positive height-SRA was found in NP-fertilized plots than in other plots, while negative correlations between SRA and SLA and LPC were found in N or P fertilized plots. The results indicate that species trade-off in nutrient acquisition and resource conservation was a key driver of SRA in competition-dominated communities following fertilization, with the linkage between SRA and traits depending on plant competition for specific soil nutrient and/or light availability. The results highlight the importance of competitive exclusion in plant community assembly following fertilization and suggest that abundant species in local communities become dominated at expense of growth while infrequent species hold an advantage in fast growth and dispersals to neighbor meta-communities.

Quantitative Assessment of Agricultural Runoff and Soil Erosion Using Mathematical Modeling: Applications in the Mediterranean Region

NASA Astrophysics Data System (ADS)

Arhonditsis, G.; Giourga, C.; Loumou, A.; Koulouri, M.

2002-09-01

Three mathematical models, the runoff curve number equation, the universal soil loss equation, and the mass response functions, were evaluated for predicting nonpoint source nutrient loading from agricultural watersheds of the Mediterranean region. These methodologies were applied to a catchment, the gulf of Gera Basin, that is a typical terrestrial ecosystem of the islands of the Aegean archipelago. The calibration of the model parameters was based on data from experimental plots from which edge-of-field losses of sediment, water runoff, and nutrients were measured. Special emphasis was given to the transport of dissolved and solid-phase nutrients from their sources in the farmers' fields to the outlet of the watershed in order to estimate respective attenuation rates. It was found that nonpoint nutrient loading due to surface losses was high during winter, the contribution being between 50% and 80% of the total annual nutrient losses from the terrestrial ecosystem. The good fit between simulated and experimental data supports the view that these modeling procedures should be considered as reliable and effective methodological tools in Mediterranean areas for evaluating potential control measures, such as management practices for soil and water conservation and changes in land uses, aimed at diminishing soil loss and nutrient delivery to surface waters. Furthermore, the modifications of the general mathematical formulations and the experimental values of the model parameters provided by the study can be used in further application of these methodologies in watersheds with similar characteristics.

Nutrient Regulation of the mTOR Complex 1 Signaling Pathway

PubMed Central

Kim, Sang Gyun; Buel, Gwen R.; Blenis, John

2013-01-01

The mammalian target of rapamycin (mTOR) is an evolutionally conserved kinase which exists in two distinct structural and functional complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Of the two complexes, mTORC1 couples nutrient abundance to cell growth and proliferation by sensing and integrating a variety of inputs arising from amino acids, cellular stresses, energy status, and growth factors. Defects in mTORC1 regulation are implicated in the development of many metabolic diseases, including cancer and diabetes. Over the past decade, significant advances have been made in deciphering the complexity of the signaling processes contributing to mTORC1 regulation and function, but the mechanistic details are still not fully understood. In particular, how amino acid availability is sensed by cells and signals to mTORC1 remains unclear. In this review, we discuss the current understanding of nutrient-dependent control of mTORC1 signaling and will focus on the key components involved in amino acid signaling to mTORC1. PMID:23694989

Capacity of biochar application to maintain energy crop productivity: soil chemistry, sorghum growth, and runoff water quality effects.

PubMed

Schnell, Ronnie W; Vietor, Donald M; Provin, Tony L; Munster, Clyde L; Capareda, Sergio

2012-01-01

Pyrolysis of crop biomass generates a by-product, biochar, which can be recycled to sustain nutrient and organic C concentrations in biomass production fields. We evaluated effects of biochar rate and application method on soil properties, nutrient balance, biomass production, and water quality. Three replications of eight sorghum [ (L.) Moench] treatments were installed in box lysimeters under greenhouse conditions. Treatments comprised increasing rates (0, 1.5, and 3.0 Mg ha) of topdressed or incorporated biochar supplemented with N fertilizer or N, P, and K fertilizer. Simulated rain was applied at 21 and 34 d after planting, and mass runoff loss of N, P, and K was measured. A mass balance of total N, P, and K was performed after 45 d. Returning 3.0 Mg ha of biochar did not affect sorghum biomass, soil total, or Mehlich-3-extractable nutrients compared to control soil. Yet, biochar contributed to increased concentration of dissolved reactive phosphorus (DRP) and mass loss of total phosphorus (TP) in simulated runoff, especially if topdressed. It was estimated that up to 20% of TP in topdressed biochar was lost in surface runoff after two rain events. Poor recovery of nutrients during pyrolysis and excessive runoff loss of nutrients for topdressed biochar, especially K, resulted in negative nutrient balances. Efforts to conserve nutrients during pyrolysis and incorporation of biochar at rates derived from annual biomass yields will be necessary for biochar use in sustainable energy crop production. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effects of Long-term Conservation Tillage on Soil Nutrients in Sloping Fields in Regions Characterized by Water and Wind Erosion

NASA Astrophysics Data System (ADS)

Tan, Chunjian; Cao, Xue; Yuan, Shuai; Wang, Weiyu; Feng, Yongzhong; Qiao, Bo

2015-12-01

Conservation tillage is commonly used in regions affected by water and wind erosion. To understand the effects of conservation tillage on soil nutrients and yield, a long-term experiment was set up in a region affected by water and wind erosion on the Loess Plateau. The treatments used were traditional tillage (CK), no tillage (NT), straw mulching (SM), plastic-film mulching (PM), ridging and plastic-film mulching (RPM) and intercropping (In). Our results demonstrate that the available nutrients in soils subjected to non-traditional tillage treatments decreased during the first several years and then remained stable over the last several years of the experiment. The soil organic matter and total nitrogen content increased gradually over 6 years in all treatments except CK. The nutrient content of soils subjected to conservative tillage methods, such as NT and SM, were significantly higher than those in soils under the CK treatment. Straw mulching and film mulching effectively reduced an observed decrease in soybean yield. Over the final 6 years of the experiment, soybean yields followed the trend RPM > PM > SM > NT > CK > In. This trend has implications for controlling soil erosion and preventing non-point source pollution in sloping fields by sacrificing some food production.

Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

NASA Astrophysics Data System (ADS)

Rusu, Dr.; Gus, Dr.; Bogdan, Dr.; Moraru, Dr.; Pop, Dr.; Clapa, Dr.; Pop, Drd.

2009-04-01

The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter , gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less fuel for preparing the germination bed. Presently it is necessary a change concerning the concept of conservation practices and a new approach regarding the control of erosion. The real conservation of soil must be expanded beyond the traditional understanding of soil erosion. The real soil conservation is represented by carbon management. We need to focus to another level concerning conservation by focusing on of soil quality. Carbon management is necessary for a complex of matters including soil, water management, field productivity, biological fuel and climatic change. Profound research is necessary in order to establish the carbon sequestration practices and their implementation impact.

Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

NASA Astrophysics Data System (ADS)

Rusu, T.; Gus, P.; Bogdan, I.; Moraru, P.; Pop, A.; Clapa, D.; Pop, L.

2009-04-01

The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter, gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less fuel for preparing the germination bed. Presently it is necessary a change concerning the concept of conservation practices and a new approach regarding the control of erosion. The real conservation of soil must be expanded beyond the traditional understanding of soil erosion. The real soil conservation is represented by carbon management. We need to focus to another level concerning conservation by focusing on of soil quality. Carbon management is necessary for a complex of matters including soil, water management, field productivity, biological fuel and climatic change.

Monitoring TASCC Injections Using A Field-Ready Wet Chemistry Nutrient Autoanalyzer

NASA Astrophysics Data System (ADS)

Snyder, L. E.; Herstand, M. R.; Bowden, W. B.

2011-12-01

Quantification of nutrient cycling and transport (spiraling) in stream systems is a fundamental component of stream ecology. Additions of isotopic tracer and bulk inorganic nutrient to streams have been frequently used to evaluate nutrient transfer between ecosystem compartments and nutrient uptake estimation, respectively. The Tracer Addition for Spiraling Curve Characterization (TASCC) methodology of Covino et al. (2010) instantaneously and simultaneously adds conservative and biologically active tracers to a stream system to quantify nutrient uptake metrics. In this method, comparing the ratio of mass of nutrient and conservative solute recovered in each sample throughout a breakthrough curve to that of the injectate, a distribution of spiraling metrics is calculated across a range of nutrient concentrations. This distribution across concentrations allows for both a robust estimation of ambient spiraling parameters by regression techniques, and comparison with uptake kinetic models. We tested a unique sampling strategy for TASCC injections in which samples were taken manually throughout the nutrient breakthrough curves while, simultaneously, continuously monitoring with a field-ready wet chemistry autoanalyzer. The autoanalyzer was programmed to measure concentrations of nitrate, phosphate and ammonium at the rate of one measurement per second throughout each experiment. Utilization of an autoanalyzer in the field during the experiment results in the return of several thousand additional nutrient data points when compared with manual sampling. This technique, then, allows for a deeper understanding and more statistically robust estimation of stream nutrient spiraling parameters.

Rhizodeposition flux of competitive versus conservative graminoid: contribution of exudates and root lysates as affected by N loading

NASA Astrophysics Data System (ADS)

Kastovska, Eva; Edwards, Keith; Santruckova, Hana

2017-04-01

Carbon allocation pattern represents the plant strategy for growth and nutrient capture. Plants exhibit high plasticity in their allocation pattern and belowground C partitioning in response to changes in the availability of nutrients limiting their production, namely nitrogen (N). Any shift in the belowground C fluxes and partitioning between root production, exudation and other rhizodeposits could affect the soil microbial activity and soil organic matter turnover. We studied the influence of N availability on plant allocation patterns with emphasis on belowground C fluxes of two wetland graminoids, the competitive Glyceria maxima and the conservative Carex acuta. Plants were grown in pots under two levels of N availability. We combined pulse-labeling of plants with 13CO2 to track recent assimilates with estimation of the root death rate calculated from the difference between gross and net root growth rates for assessing the rhizodeposition flux to soil, and the contribution of root exudates and lysates from root turnover. We found that higher N supply enhanced root biomass and, subsequently, the total rhizodeposition. Both species shifted partitioning of belowground C towards higher mass-specific root production and turnover, with lower investments into root exudation. Therefore, the rhizodeposition flux was enriched in root-derived lysates over soluble exudates. Root exudates accounted for 50-70% of the rhizodeposition flux in conditions of low N availability, while it was only 20-40% under high N availability. The N fertilization induced changes in belowground C fluxes were species-specific, with more pronounced changes in the conservative Carex than the competitive Glyceria. In summary, soil N loading enhanced total C rhizodeposition and, simultaneously, the proportion of predominantly more complex root lysates over soluble root exudates, with potential implications for soil organic matter dynamics. Our results further stress the importance of species-specific responses to N loading in predicting total rhizodeposition flux and changes in its quality.

Nutrient Removal in Wastewater Treatment

ERIC Educational Resources Information Center

Shah, Kanti L.

1973-01-01

Discusses the sources and effects of nutrients in wastewater, and the methods of their removal in wastewater treatment. In order to conserve water resources and eliminate the cost of nutrient removal, treated effluent should be used wherever possible for irrigation, since it contains all the ingredients for proper plant growth. (JR)

Nitrogen sources and cycling revealed by dual isotopes of nitrate in a complex urbanized environment.

PubMed

Archana, Anand; Thibodeau, Benoit; Geeraert, Naomi; Xu, Min Nina; Kao, Shuh-Ji; Baker, David M

2018-06-05

Elevated nutrient inputs have led to increased eutrophication in coastal marine ecosystems worldwide. An understanding of the relative contribution of different nutrient sources is imperative for effective water quality management. Stable isotope values of nitrate (δ 15 N NO3- , δ 18 O NO3- ) can complement conventional water quality monitoring programs to help differentiate natural sources of NO 3 - from anthropogenic inputs and estimate the processes involved in N cycling within an ecosystem. We measured nutrient concentrations, δ 15 N NO3- , and δ 18 O NO3- in 76 locations along a salinity gradient from the lower end of the Pearl River Estuary, one of China's largest rivers discharging into the South China Sea, towards the open ocean. NO 3 - concentrations decreased with increasing salinity, indicative of conservative mixing of eutrophic freshwater and oligotrophic seawater. However, our data did not follow conservative mixing patterns. At salinities <20 psu, samples exhibited decreasing NO 3 - concentrations with almost unchanged NO 3 - isotope values, indicating simple dilution. At salinities >20 psu, NO 3 - concentrations decreased, while dual NO 3 - isotopes increased, suggesting mixing and/or other transformation processes. Our analysis yielded mean estimates for isotope enrichment factors ( 15 ε = -2.02‰ and 18 ε = -3.37‰), Δ(15,18) = -5.5‰ and δ 15 N NO3- - δ 15 N NO2-  = 12.3‰. After consideration of potential alternative sources (sewage, atmospheric deposition and groundwater) we concluded that there are three plausible interpretations for deviations from conservative mixing behaviour (1) NO 3 - uptake by assimilation (2) in situ NO 3 - production (from fixation-derived nitrogen and nitrification of sewage-derived effluents) and (3) input of groundwater nitrate carrying a denitrification signal. Through this study, we propose a simple workflow that incorporates a synthesis of numerous isotope-based studies to constrain sources and behaviour of NO 3 - in urbanized marine environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Regional effects of agricultural conservation practices on nutrient transport

Treesearch

Anna Maria Garcia; Richard B. Alexander; Jeffrey G. Arnold; Lee Norfleet; Mike White; Dale M. Robertson; Gregory Schwarz

2016-01-01

The Conservation Effects Assessment Program (CEAP), initiated by USDA Natural Resources Conservation Service (NRCS), has the goal of quantifying the environmental benefits of agricultural conservation practices. As part of this effort, detailed farmer surveyswere compiled to document the adoption of conservation practices. Survey data showed that up to 38...

Predictive modeling of transient storage and nutrient uptake: Implications for stream restoration

USGS Publications Warehouse

O'Connor, Ben L.; Hondzo, Miki; Harvey, Judson W.

2010-01-01

This study examined two key aspects of reactive transport modeling for stream restoration purposes: the accuracy of the nutrient spiraling and transient storage models for quantifying reach-scale nutrient uptake, and the ability to quantify transport parameters using measurements and scaling techniques in order to improve upon traditional conservative tracer fitting methods. Nitrate (NO3–) uptake rates inferred using the nutrient spiraling model underestimated the total NO3– mass loss by 82%, which was attributed to the exclusion of dispersion and transient storage. The transient storage model was more accurate with respect to the NO3– mass loss (±20%) and also demonstrated that uptake in the main channel was more significant than in storage zones. Conservative tracer fitting was unable to produce transport parameter estimates for a riffle-pool transition of the study reach, while forward modeling of solute transport using measured/scaled transport parameters matched conservative tracer breakthrough curves for all reaches. Additionally, solute exchange between the main channel and embayment surface storage zones was quantified using first-order theory. These results demonstrate that it is vital to account for transient storage in quantifying nutrient uptake, and the continued development of measurement/scaling techniques is needed for reactive transport modeling of streams with complex hydraulic and geomorphic conditions.

Reducing fertilizer-nitrogen losses from rowcrop landscapes: Insights and implications from a spatially explicit watershed model

USGS Publications Warehouse

McLellan, Eileen; Schilling, Keith; Robertson, Dale M.

2015-01-01

We present conceptual and quantitative models that predict changes in fertilizer-derived nitrogen delivery from rowcrop landscapes caused by agricultural conservation efforts implemented to reduce nutrient inputs and transport and increase nutrient retention in the landscape. To evaluate the relative importance of changes in the sources, transport, and sinks of fertilizer-derived nitrogen across a region, we use the spatially explicit SPAtially Referenced Regression On Watershed attributes watershed model to map the distribution, at the small watershed scale within the Upper Mississippi-Ohio River Basin (UMORB), of: (1) fertilizer inputs; (2) nutrient attenuation during delivery of those inputs to the UMORB outlet; and (3) nitrogen export from the UMORB outlet. Comparing these spatial distributions suggests that the amount of fertilizer input and degree of nutrient attenuation are both important in determining the extent of nitrogen export. From a management perspective, this means that agricultural conservation efforts to reduce nitrogen export would benefit by: (1) expanding their focus to include activities that restore and enhance nutrient processing in these highly altered landscapes; and (2) targeting specific types of best management practices to watersheds where they will be most valuable. Doing so successfully may result in a shift in current approaches to conservation planning, outreach, and funding.

SIRT3 Deacetylates ATP Synthase F1 Complex Proteins in Response to Nutrient- and Exercise-Induced Stress

PubMed Central

Vassilopoulos, Athanassios; Pennington, J. Daniel; Andresson, Thorkell; Rees, David M.; Bosley, Allen D.; Fearnley, Ian M.; Ham, Amy; Flynn, Charles Robb; Hill, Salisha; Rose, Kristie Lindsey; Kim, Hyun-Seok; Walker, John E.

2014-01-01

Abstract Aims: Adenosine triphosphate (ATP) synthase uses chemiosmotic energy across the inner mitochondrial membrane to convert adenosine diphosphate and orthophosphate into ATP, whereas genetic deletion of Sirt3 decreases mitochondrial ATP levels. Here, we investigate the mechanistic connection between SIRT3 and energy homeostasis. Results: By using both in vitro and in vivo experiments, we demonstrate that ATP synthase F1 proteins alpha, beta, gamma, and Oligomycin sensitivity-conferring protein (OSCP) contain SIRT3-specific reversible acetyl-lysines that are evolutionarily conserved and bind to SIRT3. OSCP was further investigated and lysine 139 is a nutrient-sensitive SIRT3-dependent deacetylation target. Site directed mutants demonstrate that OSCPK139 directs, at least in part, mitochondrial ATP production and mice lacking Sirt3 exhibit decreased ATP muscle levels, increased ATP synthase protein acetylation, and an exercise-induced stress-deficient phenotype. Innovation: This work connects the aging and nutrient response, via SIRT3 direction of the mitochondrial acetylome, to the regulation of mitochondrial energy homeostasis under nutrient-stress conditions by deacetylating ATP synthase proteins. Conclusion: Our data suggest that acetylome signaling contributes to mitochondrial energy homeostasis by SIRT3-mediated deacetylation of ATP synthase proteins. Antioxid. Redox Signal. 21, 551–564. PMID:24252090

Contributions of processed foods to dietary intake in the US from 2003-2008: a report of the Food and Nutrition Science Solutions Joint Task Force of the Academy of Nutrition and Dietetics, American Society for Nutrition, Institute of Food Technologists, and International Food Information Council.

PubMed

Eicher-Miller, Heather A; Fulgoni, Victor L; Keast, Debra R

2012-11-01

Processed foods are an integral part of American diets, but a comparison of the nutrient contribution of foods by level of processing with the recommendations of the Dietary Guidelines for Americans regarding nutrients to encourage or to reduce has not been documented. The mean reported daily dietary intakes of these nutrients and other components were examined among 25,351 participants ≥2 y of age in the 2003-2008 NHANES to determine the contribution of processed food to total intakes. Also examined was the percent contribution of each nutrient to the total reported daily nutrient intake for each of the 5 categories of food that were defined by the level of processing. All processing levels contributed to nutrient intakes, and none of the levels contributed solely to nutrients to be encouraged or solely to food components to be reduced. The processing level was a minor determinant of individual foods' nutrient contribution to the diet and, therefore, should not be a primary factor when selecting a balanced diet.

Impacts of Soil and Water Conservation Practices on Crop Yield, Run-off, Soil Loss and Nutrient Loss in Ethiopia: Review and Synthesis.

PubMed

Adimassu, Zenebe; Langan, Simon; Johnston, Robyn; Mekuria, Wolde; Amede, Tilahun

2017-01-01

Research results published regarding the impact of soil and water conservation practices in the highland areas of Ethiopia have been inconsistent and scattered. In this paper, a detailed review and synthesis is reported that was conducted to identify the impacts of soil and water conservation practices on crop yield, surface run-off, soil loss, nutrient loss, and the economic viability, as well as to discuss the implications for an integrated approach and ecosystem services. The review and synthesis showed that most physical soil and water conservation practices such as soil bunds and stone bunds were very effective in reducing run-off, soil erosion and nutrient depletion. Despite these positive impacts on these services, the impact of physical soil and water conservation practices on crop yield was negative mainly due to the reduction of effective cultivable area by soil/stone bunds. In contrast, most agronomic soil and water conservation practices increase crop yield and reduce run-off and soil losses. This implies that integrating physical soil and water conservation practices with agronomic soil and water conservation practices are essential to increase both provisioning and regulating ecosystem services. Additionally, effective use of unutilized land (the area occupied by bunds) by planting multipurpose grasses and trees on the bunds may offset the yield lost due to a reduction in planting area. If high value grasses and trees can be grown on this land, farmers can harvest fodder for animals or fuel wood, both in scarce supply in Ethiopia. Growing of these grasses and trees can also help the stability of the bunds and reduce maintenance cost. Economic feasibility analysis also showed that, soil and water conservation practices became economically more viable if physical and agronomic soil and water conservation practices are integrated.

Impacts of Soil and Water Conservation Practices on Crop Yield, Run-off, Soil Loss and Nutrient Loss in Ethiopia: Review and Synthesis

NASA Astrophysics Data System (ADS)

Adimassu, Zenebe; Langan, Simon; Johnston, Robyn; Mekuria, Wolde; Amede, Tilahun

2017-01-01

Research results published regarding the impact of soil and water conservation practices in the highland areas of Ethiopia have been inconsistent and scattered. In this paper, a detailed review and synthesis is reported that was conducted to identify the impacts of soil and water conservation practices on crop yield, surface run-off, soil loss, nutrient loss, and the economic viability, as well as to discuss the implications for an integrated approach and ecosystem services. The review and synthesis showed that most physical soil and water conservation practices such as soil bunds and stone bunds were very effective in reducing run-off, soil erosion and nutrient depletion. Despite these positive impacts on these services, the impact of physical soil and water conservation practices on crop yield was negative mainly due to the reduction of effective cultivable area by soil/stone bunds. In contrast, most agronomic soil and water conservation practices increase crop yield and reduce run-off and soil losses. This implies that integrating physical soil and water conservation practices with agronomic soil and water conservation practices are essential to increase both provisioning and regulating ecosystem services. Additionally, effective use of unutilized land (the area occupied by bunds) by planting multipurpose grasses and trees on the bunds may offset the yield lost due to a reduction in planting area. If high value grasses and trees can be grown on this land, farmers can harvest fodder for animals or fuel wood, both in scarce supply in Ethiopia. Growing of these grasses and trees can also help the stability of the bunds and reduce maintenance cost. Economic feasibility analysis also showed that, soil and water conservation practices became economically more viable if physical and agronomic soil and water conservation practices are integrated.

Leaf life span and the mobility of "non-mobile" mineral nutrients - the case of boron in conifers

Treesearch

Pedro J. Aphalo; Anna W. Schoettle; Tarja Lehto

2002-01-01

Nutrient conservation is considered important for the adaptation of plants to infertile environments. The importance of leaf life spans in controlling mean residence time of nutrients in plants has usually been analyzed in relation to nutrients that can be retranslocated within the plant. Longer leaf life spans increase the mean residence time of all mineral...

Serratia marcescens Cyclic AMP Receptor Protein Controls Transcription of EepR, a Novel Regulator of Antimicrobial Secondary Metabolites.

PubMed

Stella, Nicholas A; Lahr, Roni M; Brothers, Kimberly M; Kalivoda, Eric J; Hunt, Kristin M; Kwak, Daniel H; Liu, Xinyu; Shanks, Robert M Q

2015-08-01

Serratia marcescens generates secondary metabolites and secreted enzymes, and it causes hospital infections and community-acquired ocular infections. Previous studies identified cyclic AMP (cAMP) receptor protein (CRP) as an indirect inhibitor of antimicrobial secondary metabolites. Here, we identified a putative two-component regulator that suppressed crp mutant phenotypes. Evidence supports that the putative response regulator eepR was directly transcriptionally inhibited by cAMP-CRP. EepR and the putative sensor kinase EepS were necessary for the biosynthesis of secondary metabolites, including prodigiosin- and serratamolide-dependent phenotypes, swarming motility, and hemolysis. Recombinant EepR bound to the prodigiosin and serratamolide promoters in vitro. Together, these data introduce a novel regulator of secondary metabolites that directly connects the broadly conserved metabolism regulator CRP with biosynthetic genes that may contribute to competition with other microbes. This study identifies a new transcription factor that is directly controlled by a broadly conserved transcription factor, CRP. CRP is well studied in its role to help bacteria respond to the amount of nutrients in their environment. The new transcription factor EepR is essential for the bacterium Serratia marcescens to produce two biologically active compounds, prodigiosin and serratamolide. These two compounds are antimicrobial and may allow S. marcescens to compete for limited nutrients with other microorganisms. Results from this study tie together the CRP environmental nutrient sensor with a new regulator of antimicrobial compounds. Beyond microbial ecology, prodigiosin and serratamolide have therapeutic potential; therefore, understanding their regulation is important for both applied and basic science. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection.

PubMed

Álvarez-Romero, Jorge G; Pressey, Robert L; Ban, Natalie C; Brodie, Jon

2015-01-01

Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our study demonstrates a practical approach to integrating models of catchments, land-use change, and river plumes with conservation planning software to inform prioritisation of catchment management.

Advancing Land-Sea Conservation Planning: Integrating Modelling of Catchments, Land-Use Change, and River Plumes to Prioritise Catchment Management and Protection

PubMed Central

Álvarez-Romero, Jorge G.; Pressey, Robert L.; Ban, Natalie C.; Brodie, Jon

2015-01-01

Human-induced changes to river loads of nutrients and sediments pose a significant threat to marine ecosystems. Ongoing land-use change can further increase these loads, and amplify the impacts of land-based threats on vulnerable marine ecosystems. Consequently, there is a need to assess these threats and prioritise actions to mitigate their impacts. A key question regarding prioritisation is whether actions in catchments to maintain coastal-marine water quality can be spatially congruent with actions for other management objectives, such as conserving terrestrial biodiversity. In selected catchments draining into the Gulf of California, Mexico, we employed Land Change Modeller to assess the vulnerability of areas with native vegetation to conversion into crops, pasture, and urban areas. We then used SedNet, a catchment modelling tool, to map the sources and estimate pollutant loads delivered to the Gulf by these catchments. Following these analyses, we used modelled river plumes to identify marine areas likely influenced by land-based pollutants. Finally, we prioritised areas for catchment management based on objectives for conservation of terrestrial biodiversity and objectives for water quality that recognised links between pollutant sources and affected marine areas. Our objectives for coastal-marine water quality were to reduce sediment and nutrient discharges from anthropic areas, and minimise future increases in coastal sedimentation and eutrophication. Our objectives for protection of terrestrial biodiversity covered species of vertebrates. We used Marxan, a conservation planning tool, to prioritise interventions and explore spatial differences in priorities for both objectives. Notable differences in the distributions of land values for terrestrial biodiversity and coastal-marine water quality indicated the likely need for trade-offs between catchment management objectives. However, there were priority areas that contributed to both sets of objectives. Our study demonstrates a practical approach to integrating models of catchments, land-use change, and river plumes with conservation planning software to inform prioritisation of catchment management. PMID:26714166

Dietary modulation and structure prediction of rat mucosal pentraxin (Mptx) protein and loss of function in humans

PubMed Central

van der Meer-van Kraaij, Cindy; Siezen, Roland; Kramer, Evelien; Reinders, Marjolein; Blokzijl, Hans; van der Meer, Roelof

2007-01-01

Mucosal pentraxin (Mptx), identified in rats, is a short pentraxin of unknown function. Other subfamily members are Serum amyloid P component (SAP), C-reactive protein (CRP) and Jeltraxin. Rat Mptx mRNA is predominantly expressed in colon and in vivo is strongly (30-fold) regulated by dietary heme and calcium, modulators of colon cancer risk. This renders Mptx a potential nutrient sensitive biomarker of gut health. To support a role as biomarker, we examined whether the pentraxin protein structure is conserved, whether Mptx protein is nutrient-sensitively expressed and whether Mptx is expressed in mouse and human. Sequence comparison and 3D modelling showed that rat Mptx is highly homologous to the other pentraxins. The calcium-binding site and subunit interaction sites are highly conserved, while a loop deletion and charged residues contribute to a distinctive “top” face of the pentamer. In accordance with mRNA expression, Mptx protein is strongly down-regulated in rat colon mucosa in response to high dietary heme intake. Mptx mRNA is expressed in rat and mouse colon, but not in human colon. A stop codon at the beginning of human exon two indicates loss of function, which may be related to differences in intestinal cell turnover between man and rodents. PMID:18850182

Watershed prioritization in the upper Han River basin for soil and water conservation in the South-to-North Water Transfer Project (middle route) of China.

PubMed

Wu, Haibing

2018-01-01

Watershed prioritization with the objective of identifying critical areas to undertake soil and water conservation measures was conducted in the upper Han River basin, the water source area of approximately 95,000 km 2 for the middle route of China's South-to-North Water Transfer Project. Based on the estimated soil erosion intensity in uplands and clustering analysis of measured nutrient concentrations in rivers, the basin was grouped into very-high-, high-, moderate-, and low-priority regions for water and soil conservation, respectively. The results indicated that soil erosion was primarily controlled by topography, and nutrients in rivers were associated with land use and land cover in uplands. Also, there was large spatial disparity between soil erosion intensity in the uplands and nutrient concentrations in the rivers across the basin. Analysis was then performed to prioritize the basin by the integration of the soil erosion intensity and water quality on a GIS platform in order to identify critical areas for water and soil conservation in the basin. The identified high-priority regions which occupy 5.74% of the drainage areas need immediate attention for soil and water conservation treatments, of which 5.28% is critical for soil erosion prevention and 0.46% for water conservation. Understandings of the basin environment and pollutant loading with spatial explicit are critical to the soil and water resource conservation for the interbasin water transfer project.

Effects of conservation practices on fisheries management

USDA-ARS?s Scientific Manuscript database

Beasley Lake watershed was subjected to a series of conservation management practices with the goal of reducing sediment and nutrients entering the lake via agricultural runoff. Concurrent with the application of conservation practices, the lake was renovated and restocked to produce a sports fishe...

Primary production of coral ecosystems in the Vietnamese coastal and adjacent marine waters

NASA Astrophysics Data System (ADS)

Tac-An, Nguyen; Minh-Thu, Phan; Cherbadji, I. I.; Propp, M. V.; Odintsov, V. S.; Propp, L. H.

2013-11-01

Coral reef ecosystems in coastal waters and islands of Vietnam have high primary production. Average gross primary production (GPP) in coral reef waters was 0.39 g C m-2 day-1. GPP of corals ranged from 3.12 to 4.37 g C m-2 day-1. GPP of benthic microalgae in coral reefs ranged from 2 to 10 g C m-2 day-1. GPP of macro-algae was 2.34 g C m-2 day-1. Therefore, the total of GPP of whole coral reef ecosystems could reach 7.85 to 17.10 g C m-2 day-1. Almost all values of the ratio of photosynthesis to respiration in the water bodies are higher than 1, which means these regions are autotrophic systems. Wire variation of GPP in coral reefs was contributed by species abundance of coral and organisms, nutrient supports and environmental characteristics of coral ecosystems. Coral reefs play an important ecological role of biogeochemical cycling of nutrients in waters around the reefs. These results contribute valuable information for the protection, conservation and sustainable exploitation of the natural resources in coral reef ecosystems in Vietnam.

Reducing runoff and nutrient loss from agricultural land in the Lower Mississippi River Basin

NASA Astrophysics Data System (ADS)

Reba, M. L.; Bouldin, J.; Teague, T.; Choate, J.

2011-12-01

The Lower Mississippi River Basin (LMRB) yields suspended sediment, total phosphorus, total nitrogen and silicate that are disproportionately high for the area. In addition, groundwater pumping of the alluvial aquifer has been deemed unsustainable under current practices. Much of the LMRB is used for large-scale agricultural production of primarily cotton, soybeans and rice. The incorporation of conservation practices may improve nutrient use efficiency and reduce runoff from agricultural fields. Three paired fields have been instrumented at the edge-of-field to quantify nutrients and runoff. The fields are located in northeastern Arkansas in the Little River Ditches and St. Francis watersheds. Nutrient use efficiency will be gained by utilizing variable rate fertilizer application technology. Reduced runoff will be gained through improved irrigation management. This study quantifies the runoff and nutrient loss from the first year of a 5-year study and will serve as a baseline for a comparative study of conservation practices employed on the paired fields.

Compost supplementation with nutrients and microorganisms in composting process.

PubMed

Sánchez, Óscar J; Ospina, Diego A; Montoya, Sandra

2017-11-01

The composting is an aerobic, microorganism-mediated, solid-state fermentation process by which different organic materials are transformed into more stable compounds. The product obtained is the compost, which contributes to the improvement of physical, chemical and microbiological properties of the soil. However, the compost usage in agriculture is constrained because of its long-time action and reduced supply of nutrients to the crops. To enhance the content of nutrients assimilable by the plants in the compost, its supplementation with nutrients and inoculation with microorganisms have been proposed. The objective of this work was to review the state of the art on compost supplementation with nutrients and the role played by the microorganisms involved (or added) in their transformation during the composting process. The phases of composting are briefly compiled and different strategies for supplementation are analyzed. The utilization of nitrogenous materials and addition of microorganisms fixing nitrogen from the atmosphere or oxidizing ammonia into more assimilable for plants nitrogenous forms are analyzed. Several strategies for nitrogen conservation during composting are presented as well. The supplementation with phosphorus and utilization of microorganisms solubilizing phosphorus and potassium are also discussed. Main groups of microorganisms relevant during the composting process are described as well as most important strategies to identify them. In general, the development of this type of nutrient-enriched bio-inputs requires research and development not only in the supplementation of compost itself, but also in the isolation and identification of microorganisms and genes allowing the degradation and conversion of nitrogenous substances and materials containing potassium and phosphorus present in the feedstocks undergoing the composting process. In this sense, most important research trends and strategies to increase nutrient content in the compost are provided in this work. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimating the effects of wetland conservation practices in croplands: Approaches for modeling in CEAP–Cropland Assessment

USGS Publications Warehouse

De Steven, Diane; Mushet, David

2018-01-01

Quantifying the current and potential benefits of conservation practices can be a valuable tool for encouraging greater practice adoption on agricultural lands. A goal of the CEAP-Cropland Assessment is to estimate the environmental effects of conservation practices that reduce losses (exports) of soil, nutrients, and pesticides from farmlands to streams and rivers. The assessment approach combines empirical data on reported cropland practices with simulation modeling that compares field-level exports for scenarios “with practices” and “without practices.” Conserved, restored, and created wetlands collectively represent conservation practices that can influence sediment and nutrient exports from croplands. However, modeling the role of wetlands within croplands presents some challenges, including the potential for negative impacts of sediment and nutrient inputs on wetland functions. This Science Note outlines some preliminary solutions for incorporating wetlands and wetland practices into the CEAP-Cropland modeling framework. First, modeling the effects of wetland practices requires identifying wetland hydrogeomorphic type and accounting for the condition of both the wetland and an adjacent upland zone. Second, modeling is facilitated by classifying wetland-related practices into two functional categories (wetland and upland buffer). Third, simulating practice effects requires alternative field configurations to account for hydrological differences among wetland types. These ideas are illustrated for two contrasting wetland types (riparian and depressional).

Coral-Associated Bacterial Diversity Is Conserved across Two Deep-Sea Anthothela Species

PubMed Central

Lawler, Stephanie N.; Kellogg, Christina A.; France, Scott C.; Clostio, Rachel W.; Brooke, Sandra D.; Ross, Steve W.

2016-01-01

Cold-water corals, similar to tropical corals, contain diverse and complex microbial assemblages. These bacteria provide essential biological functions within coral holobionts, facilitating increased nutrient utilization and production of antimicrobial compounds. To date, few cold-water octocoral species have been analyzed to explore the diversity and abundance of their microbial associates. For this study, 23 samples of the family Anthothelidae were collected from Norfolk (n = 12) and Baltimore Canyons (n = 11) from the western Atlantic in August 2012 and May 2013. Genetic testing found that these samples comprised two Anthothela species (Anthothela grandiflora and Anthothela sp.) and Alcyonium grandiflorum. DNA was extracted and sequenced with primers targeting the V4–V5 variable region of the 16S rRNA gene using 454 pyrosequencing with GS FLX Titanium chemistry. Results demonstrated that the coral host was the primary driver of bacterial community composition. Al. grandiflorum, dominated by Alteromonadales and Pirellulales had much higher species richness, and a distinct bacterial community compared to Anthothela samples. Anthothela species (A. grandiflora and Anthothela sp.) had very similar bacterial communities, dominated by Oceanospirillales and Spirochaetes. Additional analysis of core-conserved bacteria at 90% sample coverage revealed genus level conservation across Anthothela samples. This core included unclassified Oceanospirillales, Kiloniellales, Campylobacterales, and genus Spirochaeta. Members of this core were previously recognized for their functional capabilities in nitrogen cycling and suggest the possibility of a nearly complete nitrogen cycle within Anthothela species. Overall, many of the bacterial associates identified in this study have the potential to contribute to the acquisition and cycling of nutrients within the coral holobiont. PMID:27092120

Coral-associated bacterial diversity is conserved across two deep-sea Anthothela species

USGS Publications Warehouse

Lawler, Stephanie N.; Kellogg, Christina A.; France, Scott C; Clostio, Rachel W; Brooke, Sandra D.; Ross, Steve W.

2016-01-01

Cold-water corals, similar to tropical corals, contain diverse and complex microbial assemblages. These bacteria provide essential biological functions within coral holobionts, facilitating increased nutrient utilization and production of antimicrobial compounds. To date, few cold-water octocoral species have been analyzed to explore the diversity and abundance of their microbial associates. For this study, 23 samples of the family Anthothelidae were collected from Norfolk (n = 12) and Baltimore Canyons (n = 11) from the western Atlantic in August 2012 and May 2013. Genetic testing found that these samples comprised two Anthothela species (Anthothela grandiflora and Anthothela sp.) and Alcyonium grandiflorum. DNA was extracted and sequenced with primers targeting the V4-V5 variable region of the 16S rRNA gene using 454 pyrosequencing with GS FLX Titanium chemistry. Results demonstrated that the coral host was the primary driver of bacterial community composition. Al. grandiflorum, dominated by Alteromonadales and Pirellulales had much higher species richness, and a distinct bacterial community compared to Anthothela samples. Anthothela species (A. grandiflora and Anthothela sp.) had very similar bacterial communities, dominated by Oceanospirillales and Spirochaetes. Additional analysis of core-conserved bacteria at 90% sample coverage revealed genus level conservation across Anthothela samples. This core included unclassified Oceanospirillales, Kiloniellales, Campylobacterales, and genus Spirochaeta. Members of this core were previously recognized for their functional capabilities in nitrogen cycling and suggest the possibility of a nearly complete nitrogen cycle within Anthothela species. Overall, many of the bacterial associates identified in this study have the potential to contribute to the acquisition and cycling of nutrients within the coral holobiont.

Plant Nutrient Testing and Analysis in Forest and Conservation Nurseries

Treesearch

Thomas D. Landis; Diane L. Haase; R. Kasten Dumroese

2005-01-01

Supplying mineral nutrients at the proper rate and in the proper balance has a major effect on seedling growth rate but, more importantly, on seedling quality. In addition, mounting concerns about fertilizer pollution are increasing awareness of the benefits of precision fertilization. Because they reflect actual mineral nutrient uptake, plant tissue tests are the best...

A Regional Assessment of the Effects of Conservation Practices on In-stream Water Quality

NASA Astrophysics Data System (ADS)

Garcia, A. M.; Alexander, R. B.; Arnold, J.; Norfleet, L.; Robertson, D. M.; White, M.

2011-12-01

The Conservation Effects Assessment Program (CEAP), initiated by USDA Natural Resources Conservation Service (NRCS), has the goal of quantifying the environmental benefits of agricultural conservation practices. As part of this effort, detailed farmer surveys were compiled to document the adoption of conservation practices. Survey data showed that up to 38 percent of cropland in the Upper Mississippi River basin is managed to reduce sediment, nutrient and pesticide loads from agricultural activities. The broader effects of these practices on downstream water quality are challenging to quantify. The USDA-NRCS recently reported results of a study that combined farmer surveys with process-based models to deduce the effect of conservation practices on sediment and chemical loads in farm runoff and downstream waters. As a follow-up collaboration, USGS and USDA scientists conducted a semi-empirical assessment of the same suite of practices using the USGS SPARROW (SPAtially Referenced Regression On Watershed attributes) modeling framework. SPARROW is a hybrid statistical and mechanistic stream water quality model of annual conditions that has been used extensively in studies of nutrient sources and delivery. In this assessment, the USDA simulations of the effects of conservation practices on loads in farm runoff were used as an explanatory variable (i.e., change in farm loads per unit area) in a component of an existing a SPARROW model of the Upper Midwest. The model was then re-calibrated and tested to determine whether the USDA estimate of conservation adoption intensity explained a statistically significant proportion of the spatial variability in stream nutrient loads in the Upper Mississippi River basin. The results showed that the suite of conservation practices that NRCS has catalogued as complete nutrient and sediment management are a statistically significant feature in the Midwestern landscape associated with phosphorous runoff and delivery to downstream waters. Effects on the delivery of nitrogen will be also be studied. Estimates of the magnitude of this effect using SPARROW indicated that phosphorus load reductions ranged from about 2 - 38% for various spatial scales. This is less than reported by the USDA CEAP simulations, which ranged from 15 - 49%. Nevertheless, the results indicated that conservation practices play a significant role in reducing phosphorus pollution from agricultural activities to downstream receiving water bodies.

Herbivorous turtle ants obtain essential nutrients from a conserved nitrogen-recycling gut microbiome.

PubMed

Hu, Yi; Sanders, Jon G; Łukasik, Piotr; D'Amelio, Catherine L; Millar, John S; Vann, David R; Lan, Yemin; Newton, Justin A; Schotanus, Mark; Kronauer, Daniel J C; Pierce, Naomi E; Moreau, Corrie S; Wertz, John T; Engel, Philipp; Russell, Jacob A

2018-03-06

Nitrogen acquisition is a major challenge for herbivorous animals, and the repeated origins of herbivory across the ants have raised expectations that nutritional symbionts have shaped their diversification. Direct evidence for N provisioning by internally housed symbionts is rare in animals; among the ants, it has been documented for just one lineage. In this study we dissect functional contributions by bacteria from a conserved, multi-partite gut symbiosis in herbivorous Cephalotes ants through in vivo experiments, metagenomics, and in vitro assays. Gut bacteria recycle urea, and likely uric acid, using recycled N to synthesize essential amino acids that are acquired by hosts in substantial quantities. Specialized core symbionts of 17 studied Cephalotes species encode the pathways directing these activities, and several recycle N in vitro. These findings point to a highly efficient N economy, and a nutritional mutualism preserved for millions of years through the derived behaviors and gut anatomy of Cephalotes ants.

Cost-effective targeting of conservation investments to reduce the northern Gulf of Mexico hypoxic zone.

PubMed

Rabotyagov, Sergey S; Campbell, Todd D; White, Michael; Arnold, Jeffrey G; Atwood, Jay; Norfleet, M Lee; Kling, Catherine L; Gassman, Philip W; Valcu, Adriana; Richardson, Jeffrey; Turner, R Eugene; Rabalais, Nancy N

2014-12-30

A seasonally occurring summer hypoxic (low oxygen) zone in the northern Gulf of Mexico is the second largest in the world. Reductions in nutrients from agricultural cropland in its watershed are needed to reduce the hypoxic zone size to the national policy goal of 5,000 km(2) (as a 5-y running average) set by the national Gulf of Mexico Task Force's Action Plan. We develop an integrated assessment model linking the water quality effects of cropland conservation investment decisions on the more than 550 agricultural subwatersheds that deliver nutrients into the Gulf with a hypoxic zone model. We use this integrated assessment model to identify the most cost-effective subwatersheds to target for cropland conservation investments. We consider targeting of the location (which subwatersheds to treat) and the extent of conservation investment to undertake (how much cropland within a subwatershed to treat). We use process models to simulate the dynamics of the effects of cropland conservation investments on nutrient delivery to the Gulf and use an evolutionary algorithm to solve the optimization problem. Model results suggest that by targeting cropland conservation investments to the most cost-effective location and extent of coverage, the Action Plan goal of 5,000 km(2) can be achieved at a cost of $2.7 billion annually. A large set of cost-hypoxia tradeoffs is developed, ranging from the baseline to the nontargeted adoption of the most aggressive cropland conservation investments in all subwatersheds (estimated to reduce the hypoxic zone to less than 3,000 km(2) at a cost of $5.6 billion annually).

Nutrient foraging strategies are associated with productivity and population growth in forest shrubs

PubMed Central

Stone, Bram W. G.; Faillace, Cara A.; Lafond, Jonathan J.; Baumgarten, Joni M.; Mozdzer, Thomas J.; Dighton, John; Meiners, Scott J.; Grabosky, Jason C.; Ehrenfeld, Joan G.

2017-01-01

Background and Aims Temperate deciduous forest understoreys are experiencing widespread changes in community composition, concurrent with increases in rates of nitrogen supply. These shifts in plant abundance may be driven by interspecific differences in nutrient foraging (i.e. conservative vs. acquisitive strategies) and, thus, adaptation to contemporary nutrient loading conditions. This study sought to determine if interspecific differences in nutrient foraging could help explain patterns of shrub success and decline in eastern North American forests. Methods Using plants grown in a common garden, fine root traits associated with nutrient foraging were measured for six shrub species. Traits included the mean and skewness of the root diameter distribution, specific root length (SRL), C:N ratio, root tissue density, arbuscular mycorrhizal colonization and foraging precision. Above- and below-ground productivity were also determined for the same plants, and population growth rates were estimated using data from a long-term study of community dynamics. Root traits were compared among species and associations among root traits, measures of productivity and rates of population growth were evaluated. Key Results Species fell into groups having thick or thin root forms, which correspond to conservative vs. acquisitive nutrient foraging strategies. Interspecific variation in root morphology and tissue construction correlated with measures of productivity and rates of cover expansion. Of the four species with acquisitive traits, three were introduced species that have become invasive in recent decades, and the fourth was a weedy native. In contrast, the two species with conservative traits were historically dominant shrubs that have declined in abundance in eastern North American forests. Conclusions In forest understoreys of eastern North America, elevated nutrient availability may impose a filter on species success in addition to above-ground processes such as herbivory and overstorey canopy conditions. Shrubs that have root traits associated with rapid uptake of soil nutrients may be more likely to increase in abundance, while species without such traits may be less likely to keep pace with more productive species. PMID:28119293

Agricultural conservation planning framework: 1. Developing multipractice watershed planning scenarios and assessing nutrient reduction potential.

PubMed

Tomer, M D; Porter, S A; Boomer, K M B; James, D E; Kostel, J A; Helmers, M J; Isenhart, T M; McLellan, E

2015-05-01

Spatial data on soils, land use, and topography, combined with knowledge of conservation effectiveness, can be used to identify alternatives to reduce nutrient discharge from small (hydrologic unit code [HUC]12) watersheds. Databases comprising soil attributes, agricultural land use, and light detection and ranging-derived elevation models were developed for two glaciated midwestern HUC12 watersheds: Iowa's Beaver Creek watershed has an older dissected landscape, and Lime Creek in Illinois is young and less dissected. Subsurface drainage is common in both watersheds. We identified locations for conservation practices, including in-field practices (grassed waterways), edge-of-field practices (nutrient-removal wetlands, saturated buffers), and drainage-water management, by applying terrain analyses, geographic criteria, and cross-classifications to field- and watershed-scale geographic data. Cover crops were randomly distributed to fields without geographic prioritization. A set of alternative planning scenarios was developed to represent a variety of extents of implementation among these practices. The scenarios were assessed for nutrient reduction potential using a spreadsheet approach to calculate the average nutrient-removal efficiency required among the practices included in each scenario to achieve a 40% NO-N reduction. Results were evaluated in the context of the Iowa Nutrient Reduction Strategy, which reviewed nutrient-removal efficiencies of practices and established the 40% NO-N reduction as Iowa's target for Gulf of Mexico hypoxia mitigation by agriculture. In both test watersheds, planning scenarios that could potentially achieve the targeted NO-N reduction but remove <5% of cropland from production were identified. Cover crops and nutrient removal wetlands were common to these scenarios. This approach provides an interim technology to assist local watershed planning and could provide planning scenarios to evaluate using watershed simulation models. A set of ArcGIS tools is being released to enable transfer of this mapping technology. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Effectiveness of vegetation buffers surrounding playa wetlands at contaminant and sediment amelioration

USGS Publications Warehouse

Haukos, David A.; Johnson, Lacrecia A.; Smith, Loren M.; McMurry, Scott T.

2016-01-01

Playa wetlands, the dominant hydrological feature of the semi-arid U.S. High Plains providing critical ecosystem services, are being lost and degraded due to anthropogenic alterations of the short-grass prairie landscape. The primary process contributing to the loss of playas is filling of the wetland through accumulation of soil eroded and transported by precipitation from surrounding cultivated watersheds. We evaluated effectiveness of vegetative buffers surrounding playas in removing metals, nutrients, and dissolved/suspended sediments from precipitation runoff. Storm water runoff was collected at 10-m intervals in three buffer types (native grass, fallow cropland, and Conservation Reserve Program). Buffer type differed in plant composition, but not in maximum percent removal of contaminants. Within the initial 60 m from a cultivated field, vegetation buffers of all types removed >50% of all measured contaminants, including 83% of total suspended solids (TSS) and 58% of total dissolved solids (TDS). Buffers removed an average of 70% of P and 78% of N to reduce nutrients entering the playa. Mean maximum percent removal for metals ranged from 56% of Na to 87% of Cr. Maximum removal was typically at 50 m of buffer width. Measures of TSS were correlated with all measures of metals and nutrients except for N, which was correlated with TDS. Any buffer type with >80% vegetation cover and 30–60 m in width would maximize contaminant removal from precipitation runoff while ensuring that playas would continue to function hydrologically to provide ecosystem services. Watershed management to minimize erosion and creations of vegetation buffers could be economical and effective conservation tools for playa wetlands.

Drivers of Microbial Metabolic Activity, Biogeochemical Cycling and Associated Greenhouse Gas Production in Streambed Sediments

NASA Astrophysics Data System (ADS)

Comer-Warner, S.; Krause, S.; Gooddy, D.; Blaen, P.; Brekenfeld, N.; Wexler, S.; Kaiser, J.

2017-12-01

Hotspots of enhanced biogeochemical reactivity are produced where groundwater and surface water mixes in streambed sediments. This enhanced reactivity is due to elevated residence times and nutrient concentrations found in these areas, leading to increased rates of microbial metabolic activity. Streambed sediments, therefore, may be important in reducing catchment-wide nutrient concentrations through increased cycling. However, they also have the potential to produce high concentrations of greenhouse gases (CO2, CH4 and N2O), as end-products of respiration and intermediate products of denitrification. The hydrological and biogeochemical drivers of streambed C and N cycling, are still insufficiently understood. Here we present results from biogeochemical sampling and tracer experiments in an agricultural sandstone stream in the UK. Nutrient, DOC and greenhouse gas concentrations, as well as d13CCO2, were measured in the streambed sediment in multilevel piezometers, and nutrient concentrations, as well as d15NNO3 and d18ONO3, were measured in Diffusive Equilibrium in Thin-film Gels. Tracer experiments using both conservative (Fluorescein and NaCl) and smart (Resazurin-Resorufin) tracers were performed to determine in-stream metabolism, transient storage and solute transport times in sub-reaches of the stream. Our results show large differences in nutrient and greenhouse gas concentrations between sub-reaches dominated by gravel sediments and those dominated by sandy sediments, as well as seasonally. This suggests temperature, sediment type and residence time are key controls on streambed nutrient cycling and greenhouse gas production. The results of this study have important implications for future greenhouse gas estimates from streams and rivers, particularly as the contribution of sediment greenhouse gas production is recognised as increasingly significant.

Nutrient intake and balancing among female Colobus angolensis palliatus inhabiting structurally distinct forest areas: Effects of group, season, and reproductive state.

PubMed

Dunham, Noah T; Rodriguez-Saona, Luis E

2018-06-08

Understanding intraspecific behavioral and dietary variation is critical for assessing primate populations' abilities to persist in habitats characterized by increasing anthropogenic disturbances. While it is evident that some species exhibit considerable dietary flexibility (in terms of species-specific plant parts) in relation to habitat disturbance, it is unclear if primates are characterized by similar variation and flexibility regarding nutrient intake. This study examined the effects of group, season, and reproductive state on nutrient intake and balancing in adult female Colobus angolensis palliatus in the Diani Forest, Kenya. During July 2014 to December 2015, estimates of nutrient intake were recorded for eight females from three groups inhabiting structurally and ecologically distinct forest areas differing in tree species composition and density. There were differences in metabolizable energy (ME) and macronutrient intakes among groups, seasons, and reproductive states. Most notably, females inhabiting one of the more disturbed forest areas consumed less ME and macronutrients compared to females in the more intact forest area. Contrary to prediction, females in early lactation consumed significantly less ME and macronutrients compared to non-lactating and late lactation females. Despite differences in macronutrient intake, the relative contribution of macronutrients to ME were generally more conservative among groups, seasons, and reproductive states. Average daily intake ratios of non-protein energy to available protein ranged from approximately 3.5:1-4.3:1 among groups. These results indicate that female C. a. palliatus demonstrate a consistent nutrient balancing strategy despite significant intergroup differences in consumption of species-specific plant parts. Data from additional colobine species inhabiting different forest types are required to assess the extent to which nutrient balancing is constrained by phylogeny or is more flexible to local ecological conditions. © 2018 Wiley Periodicals, Inc.

Backyard Conservation: Bringing Conservation from the Countryside to Your Backyard.

ERIC Educational Resources Information Center

Wildlife Habitat Council, Silver Spring, MD.

This guide highlights 10 conservation activities, adapted from farms and ranches, that can be used in the backyard. Each activity provides background information and instructions on how to complete the activity. The activities concern: (1) tree planting; (2) wildlife habitat; (3) backyard ponds; (4) nutrient management; (5) terracing; (6) water…

Effects of canopy opening and debris deposition on fungal connectivity, phosphorus movement between litter cohorts and mass loss

Treesearch

D. Jean Lodge; Sharon A. Cantrell; Grizelle Gonzalez

2014-01-01

Fungi are important for maintaining fast rates of decomposition in low quality tropical leaf litter via immobilization and translocation of limiting nutrients from sources to sinks and conserving nutrients after disturbance. Tropical trees often have low nutrient to carbon ratios. Disturbances such as hurricanes and logging transfer a large mass of green leaves with...

Large-scale Watershed Modeling: NHDPlus Resolution with Achievable Conservation Scenarios in the Western Lake Erie Basin

NASA Astrophysics Data System (ADS)

Yen, H.; White, M. J.; Arnold, J. G.; Keitzer, S. C.; Johnson, M. V. V.; Atwood, J. D.; Daggupati, P.; Herbert, M. E.; Sowa, S. P.; Ludsin, S.; Robertson, D. M.; Srinivasan, R.; Rewa, C. A.

2016-12-01

By the substantial improvement of computer technology, large-scale watershed modeling has become practically feasible in conducting detailed investigations of hydrologic, sediment, and nutrient processes. In the Western Lake Erie Basin (WLEB), water quality issues caused by anthropogenic activities are not just interesting research subjects but, have implications related to human health and welfare, as well as ecological integrity, resistance, and resilience. In this study, the Soil and Water Assessment Tool (SWAT) and the finest resolution stream network, NHDPlus, were implemented on the WLEB to examine the interactions between achievable conservation scenarios with corresponding additional projected costs. During the calibration/validation processes, both hard (temporal) and soft (non-temporal) data were used to ensure the modeling outputs are coherent with actual watershed behavior. The results showed that widespread adoption of conservation practices intended to provide erosion control could deliver average reductions of sediment and nutrients without additional nutrient management changes. On the other hand, responses of nitrate (NO3) and dissolved inorganic phosphorus (DIP) dynamics may be different than responses of total nitrogen and total phosphorus dynamics under the same conservation practice. Model results also implied that fewer financial resources are required to achieve conservation goals if the goal is to achieve reductions in targeted watershed outputs (ex. NO3 or DIP) rather than aggregated outputs (ex. total nitrogen or total phosphorus). In addition, it was found that the model's capacity to simulate seasonal effects and responses to changing conservation adoption on a seasonal basis could provide a useful index to help alleviate additional cost through temporal targeting of conservation practices. Scientists, engineers, and stakeholders can take advantage of the work performed in this study as essential information while conducting policy making processes in the future.

Cost-effective targeting of conservation investments to reduce the northern Gulf of Mexico hypoxic zone

PubMed Central

Rabotyagov, Sergey S.; Campbell, Todd D.; White, Michael; Arnold, Jeffrey G.; Atwood, Jay; Norfleet, M. Lee; Kling, Catherine L.; Gassman, Philip W.; Valcu, Adriana; Richardson, Jeffrey; Turner, R. Eugene; Rabalais, Nancy N.

2014-01-01

A seasonally occurring summer hypoxic (low oxygen) zone in the northern Gulf of Mexico is the second largest in the world. Reductions in nutrients from agricultural cropland in its watershed are needed to reduce the hypoxic zone size to the national policy goal of 5,000 km2 (as a 5-y running average) set by the national Gulf of Mexico Task Force’s Action Plan. We develop an integrated assessment model linking the water quality effects of cropland conservation investment decisions on the more than 550 agricultural subwatersheds that deliver nutrients into the Gulf with a hypoxic zone model. We use this integrated assessment model to identify the most cost-effective subwatersheds to target for cropland conservation investments. We consider targeting of the location (which subwatersheds to treat) and the extent of conservation investment to undertake (how much cropland within a subwatershed to treat). We use process models to simulate the dynamics of the effects of cropland conservation investments on nutrient delivery to the Gulf and use an evolutionary algorithm to solve the optimization problem. Model results suggest that by targeting cropland conservation investments to the most cost-effective location and extent of coverage, the Action Plan goal of 5,000 km2 can be achieved at a cost of $2.7 billion annually. A large set of cost-hypoxia tradeoffs is developed, ranging from the baseline to the nontargeted adoption of the most aggressive cropland conservation investments in all subwatersheds (estimated to reduce the hypoxic zone to less than 3,000 km2 at a cost of $5.6 billion annually). PMID:25512489

Manure nutrient management effects in the Leon River Watershed

USDA-ARS?s Scientific Manuscript database

The Leon River Watershed (LRW) in central Texas is a Benchmark and Special Emphasis watershed within the Conservation Effects Assessment Project (CEAP) located in central Texas. Model simulations from 1977 through 2006 were used to evaluate six manure nutrient management scenarios that reflect reali...

Can rice (Oryza sativa) mitigate pesticides and nutrients in agricultural runoff?

USDA-ARS?s Scientific Manuscript database

Phytoremediation of nutrients and pesticides in runoff is a growing conservation effort, particularly in agriculturally intensive areas such as the lower Mississippi River Valley. In the current study, rice (Oryza sativa) was examined for its mitigation capacity of nitrogen, phosphorus, diazinon, a...

Water-quality assessment of the Lower Grand River Basin, Missouri and Iowa, USA, in support of integrated conservation practices

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.

2016-01-01

The effectiveness of agricultural conservation programmes to adequately reduce nutrient exports to receiving streams and to help limit downstream hypoxia issues remains a concern. Quantifying programme success can be difficult given that short-term basin changes may be masked by long-term water-quality shifts. We evaluated nutrient export at stream sites in the 44 months that followed a period of increased, integrated conservation implementation within the Lower Grand River Basin. These short-term responses were then compared with export that occurred in the main stem and adjacent rivers in northern Missouri over a 22-year period to better contextualize any recent changes. Results indicate that short-term (October 2010 through May 2014) total nitrogen (TN) concentrations in the Grand River were 20% less than the long-term average, and total phosphorus (TP) concentrations were 23% less. Nutrient reductions in the short term were primarily the result of the less-than-average precipitation and, consequently, streamflow that was 36% below normal. Therefore, nutrient concentrations measured in tributary streams were likely less than normal during the implementation period. Northern Missouri streamflow-normalized TN concentrations remained relatively flat or declined over the period 1991 through 2013 likely because available sources of nitrogen, determined as the sum of commercial fertilizers, available animal manures and atmospheric inputs, were typically less than crop requirement for much of that time frame. Conversely, flow-normalized stream TP concentrations increased over the past 22 years in northern Missouri streams, likely in response to many years of phosphorus inputs in excess of crop requirements. Stream nutrient changes were most pronounced during periods that coincided with the major tillage, planting and growth phases of row crops and increased streamflow. Nutrient reduction strategies targeted at the period February through June would likely have the greatest impact on reducing nutrient export from the basin. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Early-stage changes in natural (13)C and (15)N abundance and nutrient dynamics during different litter decomposition.

PubMed

Gautam, Mukesh Kumar; Lee, Kwang-Sik; Song, Byeong-Yeol; Lee, Dongho; Bong, Yeon-Sik

2016-05-01

Decomposition, nutrient, and isotopic (δ(13)C and δ(15)N) dynamics during 1 year were studied for leaf and twig litters of Pinus densiflora, Castanea crenata, Erigeron annuus, and Miscanthus sinensis growing on a highly weathered soil with constrained nutrient supply using litterbags in a cool temperate region of South Korea. Decay constant (k/year) ranged from 0.58 to 1.29/year, and mass loss ranged from 22.36 to 58.43 % among litter types. The results demonstrate that mass loss and nutrient dynamics of decomposing litter were influenced by the seasonality of mineralization and immobilization processes. In general, most nutrients exhibited alternate phases of rapid mineralization followed by gradual immobilization, except K, which was released throughout the field incubation. At the end of study, among all the nutrients only N and P showed net immobilization. Mobility of different nutrients from decomposing litter as the percentage of initial litter nutrient concentration was in the order of K > Mg > Ca > N ≈ P. The δ(13)C (0.32-6.70 ‰) and δ(15)N (0.74-3.90 ‰) values of residual litters showed nonlinear increase and decrease, respectively compared to initial isotopic values during decomposition. Litter of different functional types and chemical quality converged toward a conservative nutrient use strategy through mechanisms of slow decomposition and slow nutrient mobilization. Our results indicate that litter quality and season, are the most important regulators of litter decomposition in these forests. The results revealed significant relationships between litter decomposition rates and N, C:N ratio and P, and seasonality (temperature). These results and the convergence of different litters towards conservative nutrient use in these nutrient constrained ecosystems imply optimization of litter management because litter removal can have cascading effects on litter decomposition and nutrient availability in these systems.

Characterization and Placement of Wetlands for Integrated Conservation Practice Planning

EPA Science Inventory

Constructed wetlands have been recognized as an efficient and cost-effective conservation practice to protect water quality through reducing the transport of sediments and nutrients from upstream croplands to downstream water bodies. The challenge resides in targeting the strateg...

Nutrient foraging strategies are associated with productivity and population growth in forest shrubs.

PubMed

Caplan, Joshua S; Stone, Bram W G; Faillace, Cara A; Lafond, Jonathan J; Baumgarten, Joni M; Mozdzer, Thomas J; Dighton, John; Meiners, Scott J; Grabosky, Jason C; Ehrenfeld, Joan G

2017-04-01

Temperate deciduous forest understoreys are experiencing widespread changes in community composition, concurrent with increases in rates of nitrogen supply. These shifts in plant abundance may be driven by interspecific differences in nutrient foraging (i.e. conservative vs. acquisitive strategies) and, thus, adaptation to contemporary nutrient loading conditions. This study sought to determine if interspecific differences in nutrient foraging could help explain patterns of shrub success and decline in eastern North American forests. Using plants grown in a common garden, fine root traits associated with nutrient foraging were measured for six shrub species. Traits included the mean and skewness of the root diameter distribution, specific root length (SRL), C:N ratio, root tissue density, arbuscular mycorrhizal colonization and foraging precision. Above- and below-ground productivity were also determined for the same plants, and population growth rates were estimated using data from a long-term study of community dynamics. Root traits were compared among species and associations among root traits, measures of productivity and rates of population growth were evaluated. Species fell into groups having thick or thin root forms, which correspond to conservative vs. acquisitive nutrient foraging strategies. Interspecific variation in root morphology and tissue construction correlated with measures of productivity and rates of cover expansion. Of the four species with acquisitive traits, three were introduced species that have become invasive in recent decades, and the fourth was a weedy native. In contrast, the two species with conservative traits were historically dominant shrubs that have declined in abundance in eastern North American forests. In forest understoreys of eastern North America, elevated nutrient availability may impose a filter on species success in addition to above-ground processes such as herbivory and overstorey canopy conditions. Shrubs that have root traits associated with rapid uptake of soil nutrients may be more likely to increase in abundance, while species without such traits may be less likely to keep pace with more productive species. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Innate sensors of pathogen and stress: linking inflammation to obesity.

PubMed

Jin, Chengcheng; Flavell, Richard A

2013-08-01

Pathogen and nutrient response pathways are evolutionarily conserved and highly integrated to regulate metabolic and immune homeostasis. Excessive nutrients can be sensed by innate pattern recognition receptors as danger signals either directly or through production of endogenous ligands or modulation of intestinal microbiota. This triggers the activation of downstream inflammatory cascades involving nuclear factor κB and mitogen-activated protein kinase and ultimately induces the production of inflammatory cytokines and immune cell infiltration in various metabolic tissues. The chronic low-grade inflammation in the brain, islet, liver, muscle, and adipose tissue further promotes insulin resistance, energy imbalance, and impaired glucose/lipid metabolism, contributing to the metabolic complications of obesity, such as diabetes and atherosclerosis. In addition, innate pathogen receptors have now emerged as a critical link between the intestinal microbiota and host metabolism. In this review we summarize recent studies demonstrating the important roles of innate pathogen receptors, including Toll-like receptors, nucleotide oligomerization domain containing proteins, and inflammasomes in mediating the inflammatory response to metabolic stress in different tissues and highlight the interaction of innate pattern recognition receptors, gut microbiota, and nutrients during the development of obesity and related metabolic disorders. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Autophagy in Drosophila ovaries is induced by starvation and is required for oogenesis.

PubMed

Barth, J M I; Szabad, J; Hafen, E; Köhler, K

2011-06-01

Autophagy, an evolutionarily conserved lysosome-mediated degradation, promotes cell survival under starvation and is controlled by insulin/target of rapamycin (TOR) signaling. In Drosophila, nutrient depletion induces autophagy in the fat body. Interestingly, nutrient availability and insulin/TOR signaling also influence the size and structure of Drosophila ovaries, however, the role of nutrient signaling and autophagy during this process remains to be elucidated. Here, we show that starvation induces autophagy in germline cells (GCs) and in follicle cells (FCs) in Drosophila ovaries. This process is mediated by the ATG machinery and involves the upregulation of Atg genes. We further demonstrate that insulin/TOR signaling controls autophagy in FCs and GCs. The analysis of chimeric females reveals that autophagy in FCs, but not in GCs, is required for egg development. Strikingly, when animals lack Atg gene function in both cell types, ovaries develop normally, suggesting that the incompatibility between autophagy-competent GCs and autophagy-deficient FCs leads to defective egg development. As egg morphogenesis depends on a tightly linked signaling between FCs and GCs, we propose a model in which autophagy is required for the communication between these two cell types. Our data establish an important function for autophagy during oogenesis and contributes to the understanding of the role of autophagy in animal development.

Nutrient source and tillage influences on nitrogen availability in a Southern Piedmont corn cropping system

USDA-ARS?s Scientific Manuscript database

Combinations of conservation tillage and poultry litter (PL) can increase crop production in southeastern USA soils compared to conventional tillage (CT) and chemical fertilizer (CF). The reason for the beneficial response is usually attributed to improved water and nutrient availability. We evaluat...

Synergism between inositol polyphosphates and TOR kinase signaling in nutrient sensing, growth control, and lipid metabolism in Chlamydomonas

USDA-ARS?s Scientific Manuscript database

The networks that govern carbon metabolism and control intracellular carbon partitioning in photosynthetic cells are poorly understood. Target of rapamycin (TOR) kinase is a conserved growth regulator that integrates nutrient signals and modulates cell growth in eukaryotes, though the TOR signaling ...

Sediment and solute transport in a mountainous watershed in Valle del Cauca, Colombia

NASA Astrophysics Data System (ADS)

Guzman, C. D.; Castro, A.; Morales, A.; Hoyos, F.; Moreno, P.; Steenhuis, T. S.

2014-12-01

A main goal of this study was to improve prediction of sediment and solute transport using soil surface and soil nutrient changes, based on field measurements, within small watersheds receiving conservation measures. Sediment samples and solute concentrations were measured from two streams in the southwestern region of the Colombian Andes. Two modeling approaches for stream discharge and sediment transport predicted were used with one of these being used for nutrient transport prediction. These streams are a part of a recent initiative from a water fund established by Asobolo, Asocaña, and Cenicaña in collaboration with the Natural Capital Project to improve conservation efforts and monitor their effects. On-site soil depth changes, groundwater depth measurements, and soil nutrient concentrations were also monitored to provide more information about changes within this mountainous watershed during one part of the yearly rainy season. This information is being coupled closely with the outlet sediment concentration and solute concentration patterns to discern correlations. Lateral transects in the upper, middle, and lower part of the hillsides in the Aguaclara watershed of the Rio Bolo watershed network showed differences in soil nutrient status and soil surface depth changes. The model based on semi-distributed hydrology was able to reproduce discharge and sediment transport rates as well as the initially used model indicating available options for comparison of conservation changes in the future.

A planning approach for agricultural watersheds using precision conservation

USDA-ARS?s Scientific Manuscript database

This brief article, written for a non-technical audience, discusses a recently-developed approach for watershed planning and nutrient reduction. The approach can help local stakeholders identify conservation practices that are locally preferred and determine how those practices can be distributed ac...

Development and Validation of the Texas Best Management Practice Evaluation Tool (TBET)

USDA-ARS?s Scientific Manuscript database

Conservation planners need simple yet accurate tools to predict sediment and nutrient losses from agricultural fields to guide conservation practice implementation and increase cost-effectiveness. The Texas Best management practice Evaluation Tool (TBET), which serves as an input/output interpreter...

Multi-scale monitoring for improved nutrient management

USDA-ARS?s Scientific Manuscript database

In many watersheds, monitoring at the outlet of small watersheds has not been able to demonstrate that conservation efforts have had any impact on stream water quality. Reasons are multiple including legacy issues, time for the conservation practices to have any benefit, temporal variability of weat...

Book review: Principals of soil conservation and management

USDA-ARS?s Scientific Manuscript database

Conservation and sustainable management of soil are essential features of humankind’s reverence for Nature. As well they should be, given the essential ecosystem services that soil imparts to our world, such as producing food, moderating climate, storing and cycling water and nutrients, purifying w...

Characterization and placement of wetlands for integrated watershed conservation practice planning

USDA-ARS?s Scientific Manuscript database

Constructed wetlands have been recognized as an efficient and cost-effective conservation practice to protect water quality through reducing the transport of sediments and nutrients from upstream croplands to downstream water bodies. The challenge resides in targeting the strategic location of wetla...

Daily consumption of foods and nutrients from institutional and home sources among young children attending two contrasting day-care centers in Guatemala City.

PubMed

Vossenaar, M; Jaramillo, P M; Soto-Méndez, M-J; Panday, B; Hamelinck, V; Bermúdez, O I; Doak, C M; Mathias, P; Solomons, N W

2012-12-01

Adequate nutrition is critical to child development and institutions such as day-care centers could potentially complement children's diets to achieve optimal daily intakes. The aim of the study was to describe the full-day diet of children, examining and contrasting the relative contribution of home-derived versus institutional energy and nutrient sources. The present comparison should be considered in the domain of a case-study format. The diets of 33, 3-6 y old children attending low-income day-care centers serving either 3 or a single meal were examined. The home-diet was assessed by means of 3 non-consecutive 24-hr recalls. Estimated energy and nutrient intakes at the centers and at home were assessed and related to Recommended Nutrient Intakes (RNI). Nutrient densities, critical densities and main sources of nutrients were computed. We observed that in children attending the day-care center serving three meals, home-foods contributed less than half the daily energy (47.7%) and between 29.9% and 53.5% of daily nutrients. In children receiving only lunch outside the home, energy contribution from the home was 83.9% and 304 kcal lower than for children receiving 3 meals. Furthermore, between 59.0% and 94.8% of daily nutrients were provided at home. Daily energy, nutrient intakes and nutrient densities were well above the nutrient requirements for this age group, and particularly high for vitamin A. The overall dietary variety was superior in the situation of greater contribution of home fare, but overall the nutrient density and adequacy of the aggregate intakes did not differ in any important manner.

Revision of the 590 nutrient management standard: SERA-17 recommendations

USDA-ARS?s Scientific Manuscript database

In late 2009, NRCS requested a Working Group within SERA-17 be established to review and revise the 590 Nutrient Management Conservation Standard. This was in response to growing concern in certain areas of the U.S., that current risk assessment tools were not bringing about as great a change in pho...

Patterns of species richness and the center of diversity in modern Indo-Pacific larger foraminifera.

PubMed

Förderer, Meena; Rödder, Dennis; Langer, Martin R

2018-05-29

Symbiont-bearing Larger Benthic Foraminifera (LBF) are ubiquitous components of shallow tropical and subtropical environments and contribute substantially to carbonaceous reef and shelf sediments. Climate change is dramatically affecting carbonate producing organisms and threatens the diversity and structural integrity of coral reef ecosystems. Recent invertebrate and vertebrate surveys have identified the Coral Triangle as the planet's richest center of marine life delineating the region as a top priority for conservation. We compiled and analyzed extensive occurrence records for 68 validly recognized species of LBF from the Indian and Pacific Ocean, established individual range maps and applied Minimum Convex Polygon (MCP) and Species Distribution Model (SDM) methodologies to create the first ocean-wide species richness maps. SDM output was further used for visualizing latitudinal and longitudinal diversity gradients. Our findings provide strong support for assigning the tropical Central Indo-Pacific as the world's species-richest marine region with the Central Philippines emerging as the bullseye of LBF diversity. Sea surface temperature and nutrient content were identified as the most influential environmental constraints exerting control over the distribution of LBF. Our findings contribute to the completion of worldwide research on tropical marine biodiversity patterns and the identification of targeting centers for conservation efforts.

Community implementation dynamics: nutrient management in the New York City and Chesapeake Bay watersheds

USDA-ARS?s Scientific Manuscript database

Conservation of natural resources has implications for international, national, and local citizens. The creation of natural resource management and conservation strategies can be affected by engagement with local citizens and competing interests between agencies and stakeholders at the varying leve...

Spatial and temporal variability in the water column nutrients and pesticides of Jobos Bay

USDA-ARS?s Scientific Manuscript database

The Conservation Effects Assessment Project (CEAP) is a national, multi-agency effort to quantify the environmental benefits of best management practices used by agricultural producers participating in selected U.S. Department of Agriculture (USDA) conservation programs, including programs such as t...

Adaptive cover crop implementation and evaluation in the Chesapeake Bay watersheds

USDA-ARS?s Scientific Manuscript database

Four years of applied research, led by the USDA-ARS Choptank River Conservation Reserve Assessment Project (CEAP), have demonstrated that satellite remote sensing, used in combination with cost-share program farm implementation records, can provide a powerful tool for evaluating the nutrient conserv...

Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios.

PubMed

Yen, Haw; White, Michael J; Arnold, Jeffrey G; Keitzer, S Conor; Johnson, Mari-Vaughn V; Atwood, Jay D; Daggupati, Prasad; Herbert, Matthew E; Sowa, Scott P; Ludsin, Stuart A; Robertson, Dale M; Srinivasan, Raghavan; Rewa, Charles A

2016-11-01

Complex watershed simulation models are powerful tools that can help scientists and policy-makers address challenging topics, such as land use management and water security. In the Western Lake Erie Basin (WLEB), complex hydrological models have been applied at various scales to help describe relationships between land use and water, nutrient, and sediment dynamics. This manuscript evaluated the capacity of the current Soil and Water Assessment Tool (SWAT) to predict hydrological and water quality processes within WLEB at the finest resolution watershed boundary unit (NHDPlus) along with the current conditions and conservation scenarios. The process based SWAT model was capable of the fine-scale computation and complex routing used in this project, as indicated by measured data at five gaging stations. The level of detail required for fine-scale spatial simulation made the use of both hard and soft data necessary in model calibration, alongside other model adaptations. Limitations to the model's predictive capacity were due to a paucity of data in the region at the NHDPlus scale rather than due to SWAT functionality. Results of treatment scenarios demonstrate variable effects of structural practices and nutrient management on sediment and nutrient loss dynamics. Targeting treatment to acres with critical outstanding conservation needs provides the largest return on investment in terms of nutrient loss reduction per dollar spent, relative to treating acres with lower inherent nutrient loss vulnerabilities. Importantly, this research raises considerations about use of models to guide land management decisions at very fine spatial scales. Decision makers using these results should be aware of data limitations that hinder fine-scale model interpretation. Copyright © 2016 Elsevier B.V. All rights reserved.

Catchment Legacies and Time Lags: A Parsimonious Watershed Model to Predict the Effects of Legacy Storage on Nitrogen Export

PubMed Central

Van Meter, Kimberly J.; Basu, Nandita B.

2015-01-01

Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy) and groundwater travel time distributions (hydrologic legacy). The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures. PMID:25985290

Catchment legacies and time lags: a parsimonious watershed model to predict the effects of legacy storage on nitrogen export.

PubMed

Van Meter, Kimberly J; Basu, Nandita B

2015-01-01

Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy) and groundwater travel time distributions (hydrologic legacy). The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures.

Western Lake Erie Basin: Soft-data-constrained, NHDPlus resolution watershed modeling and exploration of applicable conservation scenarios

USGS Publications Warehouse

Yen, Haw; White, Michael J.; Arnold, Jeffrey G.; Keitzer, S. Conor; Johnson, Mari-Vaughn V; Atwood, Jay D.; Daggupati, Prasad; Herbert, Matthew E.; Sowa, Scott P.; Ludsin, Stuart A.; Robertson, Dale M.; Srinivasan, Raghavan; Rewa, Charles A.

2016-01-01

Complex watershed simulation models are powerful tools that can help scientists and policy-makers address challenging topics, such as land use management and water security. In the Western Lake Erie Basin (WLEB), complex hydrological models have been applied at various scales to help describe relationships between land use and water, nutrient, and sediment dynamics. This manuscript evaluated the capacity of the current Soil and Water Assessment Tool (SWAT2012) to predict hydrological and water quality processes within WLEB at the finest resolution watershed boundary unit (NHDPlus) along with the current conditions and conservation scenarios. The process based SWAT model was capable of the fine-scale computation and complex routing used in this project, as indicated by measured data at five gaging stations. The level of detail required for fine-scale spatial simulation made the use of both hard and soft data necessary in model calibration, alongside other model adaptations. Limitations to the model's predictive capacity were due to a paucity of data in the region at the NHDPlus scale rather than due to SWAT functionality. Results of treatment scenarios demonstrate variable effects of structural practices and nutrient management on sediment and nutrient loss dynamics. Targeting treatment to acres with critical outstanding conservation needs provides the largest return on investment in terms of nutrient loss reduction per dollar spent, relative to treating acres with lower inherent nutrient loss vulnerabilities. Importantly, this research raises considerations about use of models to guide land management decisions at very fine spatial scales. Decision makers using these results should be aware of data limitations that hinder fine-scale model interpretation.

Nutrient Contents of the Freshwater Crab, Isolapotamon bauense from Sarawak, Malaysia (Borneo).

PubMed

Grinang, Jongkar; Tyan, Pang Sing; Tuen, Andrew Alek; Das, Indraneil

2017-07-01

Data on nutrient contents of freshwater crabs are important for ecological studies and species conservation assessments, especially when the species concerned is threatened among others by habitat destruction and uncontrolled resources utilisation. Indeed comprehensive biological information is required to reconcile the needs between sustainable resources utilisation and conservation of the species. This study documents the nutrient contents of a freshwater crab, Isolapotamon bauense which is listed as 'Vulnerable' in the IUCN Red List of Threatened Species and also being harvested by local community for dietary supplement. Results show that muscles of the freshwater crab contain a substantial amount of nutrients in particular water content (male = 79.31 ± 2.30 %, female = 77.63 ± 0.56 %), protein (male = 77.47 ± 6.11 %, female = 63.28 ± 3.62 %), magnesium (male = 51.48 ± 16.10 mg/g, female = 39.73 ± 6.99 mg/g) and calcium (male = 25.50 ± 6.98 mg/g, female = 39.73 ± 6.99 mg/g). Means of nutrient contents between male and female crabs are not significantly different. It is estimated that an individual of I. bauense with weight range of 56-139 g contained on average of 0.35 ± 0.15 g of protein. Our estimation also shows that the number of individuals of the freshwater crab required to meet the recommended daily protein intakes of the community concerned is in the range 35-96 individuals for children, 130-188 individuals for adolescents, 171-179 individuals for men and 149-159 individuals for women. The results imply that harvesting of wild I. bauense as a source of protein supplement naturally may not be practical because of its relatively low population abundance, and conservation of the species for its ecological roles may thus be preferred.

Functional traits determine tree growth and ecosystem productivity of a tropical montane forest: Insights from a long-term nutrient manipulation experiment.

PubMed

Báez, Selene; Homeier, Jürgen

2018-01-01

Trait-response effects are critical to forecast community structure and biomass production in highly diverse tropical forests. Ecological theory and few observation studies indicate that trees with acquisitive functional traits would respond more strongly to higher resource availability than those with conservative traits. We assessed how long-term tree growth in experimental nutrient addition plots (N, P, and N + P) varied as a function of morphological traits, tree size, and species identity. We also evaluated how trait-based responses affected stand scale biomass production considering the community structure. We found that tree growth depended on interactions between functional traits and the type or combination of nutrients added. Common species with acquisitive functional traits responded more strongly to nutrient addition, mainly to N + P. Phosphorous enhanced the growth rates of species with acquisitive and conservative traits, had mostly positive effects on common species and neutral or negative effects in rare species. Moreover, trees receiving N + P grew faster irrespective of their initial size relative to trees in control or to trees in other treatment plots. Finally, species responses were highly idiosyncratic suggesting that community processes including competition and niche dimensionality may be altered under increased resource availability. We found no statistically significant effects of nutrient additions on aboveground biomass productivity because acquisitive species had a limited potential to increase their biomass, possibly due to their generally lower wood density. In contrast, P addition increased the growth rates of species characterized by more conservative resource strategies (with higher wood density) that were poorly represented in the plant community. We provide the first long-term experimental evidence that trait-based responses, community structure, and community processes modulate the effects of increased nutrient availability on biomass productivity in a tropical forest. © 2017 John Wiley & Sons Ltd.

Nutrient contributions and biogas potential of co-digestion of feedstocks and dairy manure.

PubMed

Ma, Guiling; Neibergs, J Shannon; Harrison, Joseph H; Whitefield, Elizabeth M

2017-06-01

This study focused on collection of data on nutrient flow and biogas yield at a commercial anaerobic digester managed with dairy manure from a 1000 cow dairy and co-digestion of additional feedstocks. Feedstocks included: blood, fish, paper pulp, out of date beverages and grease trap waste. Mass flow of inputs and outputs, nutrient concentration of inputs and outputs, and biogas yield were obtained. It was determined that manure was the primary source of nutrients to the anaerobic digester when co-digested with feedstocks. The percentage of contribution from manure to the total nutrient inputs for total nitrogen, ammonia-nitrogen, phosphorus and total solids was 46.3%, 67.7%, 32.8% and 23.4%, respectively. On average, manure contributed the greatest amount of total nitrogen and ammonia-nitrogen. Grease trap waste contributed the greatest amount of phosphorus and total solids at approximately 50%. Results demonstrated that a reliable estimate of nutrient inflow could be obtained from the product of the nutrient analyses of a single daily composite of influent subsamples times the total daily flow estimated with an in-line flow meter. This approach to estimate total daily nutrient inflow would be more cost effective than testing and summing the contribution of individual feedstocks. Data collected after liquid-solid separation confirmed that the majority (>75%) of nutrients remain with the liquid effluent portion of the manure stream. It was demonstrated that the ash concentration in solids before and after composting could be used to estimate the mass balance of total solids during the compost process. This data confirms that biogas or methane yield could be accurately measured from the ratio of % volatile solids to % total solids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Topography- and management-mediated resource gradients maintain rare and common plant diversity around paddy terraces.

PubMed

Uematsu, Yuta; Ushimaru, Atushi

2013-09-01

Examining the causes of interspecific differences in susceptibility to bidirectional land-use changes (land abandonment and use-intensification) is important for understanding the mechanisms of global biodiversity loss in agricultural landscapes. We tested the hypothesis that rare (endangered) plant species prefer wet and oligotrophic areas within topography- and management-mediated resource (soil water content, nutrient, and aboveground biomass) gradients, making them more susceptible to both abandonment and use-intensification of agricultural lands. We demonstrated that topography and management practices generated resource gradients in seminatural grasslands around traditional paddy terraces. Terraced topography and management practices produced a soil moisture gradient within levees and a nutrient gradient within paddy terraces. Both total and rare species diversity increased with soil water content. Total species diversity increased in more eutrophied areas with low aboveground biomass, whereas rare species diversity was high under oligotrophic conditions. Rare and common species were differentially distributed along the human-induced nutrient gradient, with rare species preferring wet, nutrient-poor environments in the agricultural landscapes studied. We suggest that conservation efforts should concentrate on wet, nutrient-poor areas within such landscapes, which can be located easily using land-use and topography maps. This strategy would reduce the costs of finding and conserving rare grassland species in a given agricultural landscape.

Aerosols in atmospheric chemistry and biogeochemical cycles of nutrients

NASA Astrophysics Data System (ADS)

Kanakidou, Maria; Myriokefalitakis, Stelios; Tsigaridis, Kostas

2018-06-01

Atmospheric aerosols have complex and variable compositions and properties. While scientific interest is centered on the health and climatic effects of atmospheric aerosols, insufficient attention is given to their involvement in multiphase chemistry that alters their contribution as carriers of nutrients in ecosystems. However, there is experimental proof that the nutrient equilibria of both land and marine ecosystems have been disturbed during the Anthropocene period. This review study first summarizes our current understanding of aerosol chemical processing in the atmosphere as relevant to biogeochemical cycles. Then it binds together results of recent modeling studies based on laboratory and field experiments, focusing on the organic and dust components of aerosols that account for multiphase chemistry, aerosol ageing in the atmosphere, nutrient (N, P, Fe) emissions, atmospheric transport, transformation and deposition. The human-driven contribution to atmospheric deposition of these nutrients, derived by global simulations using past and future anthropogenic emissions of pollutants, is put into perspective with regard to potential changes in nutrient limitations and biodiversity. Atmospheric deposition of nutrients has been suggested to result in human-induced ecosystem limitations with regard to specific nutrients. Such modifications favor the development of certain species against others and affect the overall functioning of ecosystems. Organic forms of nutrients are found to contribute to the atmospheric deposition of the nutrients N, P and Fe by 20%–40%, 35%–45% and 7%–18%, respectively. These have the potential to be key components of the biogeochemical cycles since there is initial proof of their bioavailability to ecosystems. Bioaerosols have been found to make a significant contribution to atmospheric sources of N and P, indicating potentially significant interactions between terrestrial and marine ecosystems. These results deserve further experimental and modeling studies to reduce uncertainties and understand the feedbacks induced by atmospheric deposition of nutrients to ecosystems.

Coral reefs: threats and conservation in an era of global change.

PubMed

Riegl, Bernhard; Bruckner, Andy; Coles, Steve L; Renaud, Philip; Dodge, Richard E

2009-04-01

Coral reefs are iconic, threatened ecosystems that have been in existence for approximately 500 million years, yet their continued ecological persistence seems doubtful at present. Anthropogenic modification of chemical and physical atmospheric dynamics that cause coral death by bleaching and newly emergent diseases due to increased heat and irradiation, as well as decline in calcification caused by ocean acidification due to increased CO(2), are the most important large-scale threats. On more local scales, overfishing and destructive fisheries, coastal construction, nutrient enrichment, increased runoff and sedimentation, and the introduction of nonindigenous invasive species have caused phase shifts away from corals. Already approximately 20% of the world's reefs are lost and approximately 26% are under imminent threat. Conservation science of coral reefs is well advanced, but its practical application has often been lagging. Societal priorites, economic pressures, and legal/administrative systems of many countries are more prone to destroy rather than conserve coral-reef ecosystems. Nevertheless, many examples of successful conservation exist from the national level to community-enforced local action. When effectively managed, protected areas have contributed to regeneration of coral reefs and stocks of associated marine resources. Local communities often support coral-reef conservation in order to raise income potential associated with tourism and/or improved resource levels. Coral reefs create an annual income in S-Florida alone of over $4 billion. Thus, no conflict between development, societal welfare, and coral-reef conservation needs to exist. Despite growing threats, it is not too late for decisive action to protect and save these economically and ecologically high-value ecosystems. Conservation science plays a critical role in designing effective strategies.

Regional effects of agricultural conservation practices on nutrient transport in the Upper Mississippi River Basin

USDA-ARS?s Scientific Manuscript database

Despite progress in the implementation of conservation practices, related improvements in water quality have been challenging to measure in larger river systems. In this paper we quantify these downstream effects by applying the empirical U.S. Geological Survey water-quality model SPARROW to inves...

Understanding Predictors of Nutrient Management Practice Diversity in Midwestern Agriculture

ERIC Educational Resources Information Center

Bates, Hanna; Arbuckle, J. Gordon, Jr.

2017-01-01

Agriculture's negative effect on water quality has become increasingly well documented. Farmers have a range of conservation practices available, yet rate of adoption is not optimal. Extension and other agricultural stakeholders play a key role in promotion of conservation practice adoption. We used survey data to examine relationships between…

A twice-paired watershed experimental design to assess stacked practices through field-edge monitoring

USDA-ARS?s Scientific Manuscript database

To improve our ability to reduce nutrient losses from agricultural lands to receiving waters, comprehensive approaches that employ a variety of conservation practices placed within and below field edges will be needed. There is a need to obtain experimental data to better understand how conservation...

Impact of buffer type on streamside nutrient concentrations in Upper Big Walnut Creek, Ohio

USDA-ARS?s Scientific Manuscript database

The identification and assessment of conservation practices continues to be important for the protection of natural resources. Buffers, also referred to as filter strips, buffer strips, riparian buffers, or vegetative filters are one of the most common types of conservation practice installed in the...

Response of non-added solutes during nutrient addition experiments in streams

NASA Astrophysics Data System (ADS)

Rodriguez-Cardona, B.; Wymore, A.; Koenig, L.; Coble, A. A.; McDowell, W. H.

2015-12-01

Nutrient addition experiments, such as Tracer Additions for Spiraling Curve Characterization (TASCC), have become widely popular as a means to study nutrient uptake dynamics in stream ecosystems. However, the impact of these additions on ambient concentrations of non-added solutes is often overlooked. TASCC addition experiments are ideal for assessing interactions among solutes because it allows for the characterization of multiple solute concentrations across a broad range of added nutrient concentrations. TASCC additions also require the addition of a conservative tracer (NaCl) to track changes in conductivity during the experimental manipulation. Despite its use as a conservative tracer, chloride (Cl) and its associated sodium (Na) might change the concentrations of other ions and non-added nutrients through ion exchange or other processes. Similarly, additions of biologically active solutes might change the concentrations of other non-added solutes. These methodological issues in nutrient addition experiments have been poorly addressed in the literature. Here we examine the response of non-added solutes to pulse additions (i.e. TASCC) of NaCl plus nitrate (NO3-), ammonium, and phosphate across biomes including temperate and tropical forests, and arctic taiga. Preliminary results demonstrate that non-added solutes respond to changes in the concentration of these added nutrients. For example, concentrations of dissolved organic nitrogen (DON) in suburban headwater streams of New Hampshire both increase and decrease in response to NO3- additions, apparently due to biotic processes. Similarly, cations such as potassium, magnesium, and calcium also increase during TASCC experiments, likely due to cation exchange processes associated with Na addition. The response of non-added solutes to short-term pulses of added nutrients and tracers needs to be carefully assessed to ensure that nutrient uptake metrics are accurate, and to detect biotic interactions that may provide insights into fundamental aspects of stream nutrient cycling.

Legacies of Human Impact: Long-Term Nitrogen Dynamics, from the Mississippi to the Mekong

NASA Astrophysics Data System (ADS)

Van Meter, K. J.; Van Cappellen, P.; Basu, N. B.

2017-12-01

Global flows of reactive nitrogen (N) have increased significantly over the last century in response to land-use change, agricultural intensification and elevated levels of atmospheric N deposition. Despite widespread implementation of a range of conservation measures to mitigate the impacts of N-intensive agriculture, N concentrations in surface waters are in many cases remaining steady or continuing to increase. Such lack of response has been attributed to legacy N stores in subsurface reservoirs that contribute to time lags between conservation measures implemented on the landscape and water quality benefits realized in receiving water bodies. It has remained unclear, however, what the magnitudes of such stores might be, and how they are partitioned between shallow soil and deeper groundwater reservoirs. In the present work, we have synthesized data to develop a comprehensive, 214-year (1800 - 2014) trajectory of N inputs to the land surface of watersheds across a global continuum of watersheds, from the Mississippi to the Mekong and beyond. Using our ELEMeNT model, a process-based model that pairs long-term nutrient input trajectories with a travel time-based approach, we have reconstructed historic nutrient yields at the outlets of major global watersheds and have estimated the magnitudes of N accumulation in both soil and groundwater pools. Our results show significant N loading above baseline levels many major watersheds before the widespread use of commercial N fertilizers, generally coinciding with periods of significant conversion of pristine land to row-crop agriculture. Our results also highlight the varying importance of biogeochemical and hydrologic N legacies across a wide distribution of climate, land use, and management. The results of the present study suggest that anthropogenic N legacies are a major driver of both current and future water quality, and that the presence of these legacies significantly impacts global nutrient cycling.

INFLUENCE OF TIDE AND WAVES ON WASHOUT OF DISSOLVED NUTRIENTS FROM THE BIOREMEDIATION ZONE OF A COARSE-SAND BEACH: APPLICATION IN OIL-SPILL BIOREMEDIATION

EPA Science Inventory

Successful bioremediation of oil-contaminated beaches requires maintenance of a sufficient quantity of growth-limiting nutrients in contact with the oiled beach materials. A conservative tracer study was conducted on a moderate-energy, sandy beach on Delaware Bay to estimate the...

Role of the check dam in land development on the Loess Plateau, China

NASA Astrophysics Data System (ADS)

Xu, Xiang-Zhou; Zhang, Luo-Hao; Zhu, Tongxin; Dang, Tian-Min; Zhang, Hong-Wu; Xu, Shi-Guo

2017-04-01

Check dam is one of the most effective measures to reduce flow connectivity, which can retain soil and water, and increase land productivity. More than 100,000 check dams have been built on the Loess Plateau since 1950s. However, quantifying the effect of check dams on water resources and water environments remains a challenge. In this study, an in-depth field investigation together with a credible statistical analysis was carried out in two representative catchments on the Loess Plateau, Nanxiaohegou Catchment and Jiuyuangou Catchment, to assess the effectiveness of check dams in soil, water and nutrients conservation. The results show: (1) Check dam plays an important role in conserving water, soil, and nutrients on the Loess Plateau. About half of the total transported water and more than 80 % of the total transported soil and nutrients, had been locally retained in the selected catchments. Hence check dams had a significant benefit to improve soil fertility in the small watersheds, and reducing water pollution downstream of dams. (2) Compared to terrace farmlands, forest lands and grasslands, check-dam lands were much more important in conserving water, soil and nutrients in the catchments. Nearly 50% of the reduced water and more than 70% of the stored soil and nutrients in the study catchments were solely retained by the check dams, whereas the area of the dam lands was less than 7% of the total conservation land area. (3) Check dams are still effective in large storms even if dams were damaged by floods. It is often assumed that check dams could only retain sediment in small flood events whereas most of the stored soil may be washed out as the dams may be destroyed in a disastrous flood. Furthermore, if a major check dam, namely the key project dam, was built in the gully outlet, the flood could be controlled, and thereupon the dam-break can be also avoided. We suggest that a compensation and incentive policy be implemented on dam building to realize the sustainable development of local economy and ecological environment.

Evaluation of long-term trends in hydrographic and nutrient parameters in a southeast US coastal river.

PubMed

Williams, Asher A; Kimball, Matthew E

2013-12-01

The Nassau River estuary is located in northeast Florida adjacent to the eutrophic St. Johns River. Historically, development has been sparse in the Nassau River's catchment; thus, the system may provide a relatively undisturbed aquatic environment. To monitor the condition of the Nassau River estuary and to discern spatial and temporal trends in water quality, nutrients and hydrographic variables were assessed throughout the estuary from 1997 to 2011. Hydrographic (temperature, salinity, total suspended solids, and turbidity) and nutrient parameters (total phosphorus, ortho-PO₄(3-), total nitrogen, NH₄(+), total Kjeldahl nitrogen, and NO₃(-)) were monitored bimonthly at 12 sites in the mesohaline and polyhaline zones of the river. Nonparametric Kendall's Tau was implemented to analyze long-term water quality patterns. Salinity was found to increase with time, particularly in the mesohaline sampling sites. Dissolved oxygen decreased over time in the estuary and hypoxic conditions became increasingly frequent in the final years of the study. Nutrients increased in the estuary, ranging from 149 to 401%. Rainfall data collected in adjacent conservation areas did not correlate well with nutrients as compared with stream discharge data collected in the basin headwaters, outside of the conservation lands, attributed here to expanding urbanization. During the study period, the Nassau basin underwent rapid human population growth and land development resulting in commensurate impacts to water quality. Nutrient and physical data collected during this study indicate that the Nassau River estuary is becoming more eutrophic with time.

Strontium source and depth of uptake shifts with substrate age in semiarid ecosystems

NASA Astrophysics Data System (ADS)

Coble, Ashley A.; Hart, Stephen C.; Ketterer, Michael E.; Newman, Gregory S.; Kowler, Andrew L.

2015-06-01

Without exogenous rock-derived nutrient sources, terrestrial ecosystems may eventually regress or reach a terminal steady state, but the degree to which exogenous nutrient sources buffer or slow to a theoretical terminal steady state remains unclear. We used strontium isotope ratios (87Sr/86Sr) as a tracer and measured 87Sr/86Sr values in aeolian dust, soils, and vegetation across a well-constrained 3 Myr semiarid substrate age gradient to determine (1) whether the contribution of atmospheric sources of rock-derived nutrients to soil and vegetation pools varied with substrate age and (2) to determine if the depth of uptake varied with substrate age. We found that aeolian-derived nutrients became increasingly important, contributing as much as 71% to plant-available soil pools and tree (Pinus edulis) growth during the latter stages of ecosystem development in a semiarid climate. The depth of nutrient uptake increased on older substrates, demonstrating that trees in arid regions can acquire nutrients from greater depths as ecosystem development progresses presumably in response to nutrient depletion in the more weathered surface soils. Our results demonstrate that global and regional aeolian transport of nutrients to local ecosystems is a vital process for ecosystem development in arid regions. Furthermore, these aeolian nutrient inputs contribute to deep soil nutrient pools, which become increasingly important for maintaining plant productivity over long time scales.

Contribution of Food Groups to Energy and Nutrient Intakes in Five Developed Countries.

PubMed

Auestad, Nancy; Hurley, Judith S; Fulgoni, Victor L; Schweitzer, Cindy M

2015-06-08

Economic growth in developing countries and globalization of the food sector is leading to increasingly similar food consumption patterns worldwide. The aim of this study was to describe similarities and differences in the contributions of main food groups to energy and nutrient intakes in five developed countries across three continents. We obtained summary reports of national food consumption survey data from Australia, France, Denmark, the Netherlands, and the United States. Survey years spanned 2003-2012; sample size ranged from 1444 to 17,386. To mitigate heterogeneity of food groups across countries, we recategorized each survey's reported food groups and subgroups into eight main food groups and, for three countries, a ninth "mixed dishes" group. We determined the percent contribution of each food group to mean daily intakes of energy, saturated fat, sodium, fiber, and ten vitamins and minerals that are commonly under-consumed. Differences in findings from surveys utilizing a foods-as-consumed versus a disaggregated or ingredients approach to food group composition and contributions from the milk and milk products group, a source of several under-consumed nutrients, were explored. Patterns of food group contributions to energy and nutrient intakes were generally similar across countries. Some differences were attributable to the analytical approach used by the surveys. For the meat/protein, milk and milk products, vegetables, and fruit groups, percent contributions to key nutrient intakes exceeded percent contributions to energy intake. The mixed dishes group provided 10%-20% of total daily energy and a similar 10%-25% of the daily intake of several nutrients. This descriptive study contributes to an understanding of food group consumption patterns in developed countries.

Contribution of Food Groups to Energy and Nutrient Intakes in Five Developed Countries

PubMed Central

Auestad, Nancy; Hurley, Judith S.; Fulgoni, Victor L.; Schweitzer, Cindy M.

2015-01-01

Economic growth in developing countries and globalization of the food sector is leading to increasingly similar food consumption patterns worldwide. The aim of this study was to describe similarities and differences in the contributions of main food groups to energy and nutrient intakes in five developed countries across three continents. We obtained summary reports of national food consumption survey data from Australia, France, Denmark, the Netherlands, and the United States. Survey years spanned 2003–2012; sample size ranged from 1444 to 17,386. To mitigate heterogeneity of food groups across countries, we recategorized each survey’s reported food groups and subgroups into eight main food groups and, for three countries, a ninth “mixed dishes” group. We determined the percent contribution of each food group to mean daily intakes of energy, saturated fat, sodium, fiber, and ten vitamins and minerals that are commonly under-consumed. Differences in findings from surveys utilizing a foods-as-consumed versus a disaggregated or ingredients approach to food group composition and contributions from the milk and milk products group, a source of several under-consumed nutrients, were explored. Patterns of food group contributions to energy and nutrient intakes were generally similar across countries. Some differences were attributable to the analytical approach used by the surveys. For the meat/protein, milk and milk products, vegetables, and fruit groups, percent contributions to key nutrient intakes exceeded percent contributions to energy intake. The mixed dishes group provided 10%–20% of total daily energy and a similar 10%–25% of the daily intake of several nutrients. This descriptive study contributes to an understanding of food group consumption patterns in developed countries. PMID:26061017

Evaluation of the Agro-EcoSystem-Watershed (AgES-W)model for estimating nutrient dynamics on a midwest agricultural watershed

USDA-ARS?s Scientific Manuscript database

In order to satisfy the requirements of Conservation Effects Assessment Project (CEAP) Watershed Assessment Study (WAS) Objective 5 (“develop and verify regional watershed models that quantify environmental outcomes of conservation practices in major agricultural regions”), a new watershed model dev...

Geographic approaches to biodiversity conservation: implications of scale and error to landscape planning

Treesearch

Curtis H. Flather; Kenneth R. Wilson; Susan A. Shriner

2009-01-01

Conservation science is concerned with understanding why distribution and abundance patterns of species vary in time and space. Although these patterns have strong signatures tied to the availability of energy and nutrients, variation in climate, physiographic heterogeneity, and differences in the structural complexity of natural vegetation, it is becoming more...

Right practice, right place: A conservation planning toolbox for meeting water quality goals in the Corn Belt

USDA-ARS?s Scientific Manuscript database

With increasing recognition that regional nutrient pollution problems will only be solved using edge-of-field and beyond-field practices, conservation planners now face the challenge of identifying the most appropriate practices and practice locations to deliver water quality outcomes. We have deve...

Effects of lawn fertilizer on nutrient concentration in runoff from lakeshore lawns, Lauderdale Lakes, Wisconsin

USGS Publications Warehouse

Garn, Herbert S.

2002-01-01

Transport of nutrients (primarily forms of nitrogen and phosphorus) to lakes and resulting accelerated eutrophication are serious concerns for planners and managers of lakes in urban and developing suburban areas of the country. Runoff from urban land surfaces such as streets, lawns, and rooftops has been noted to contain high concentrations of nutrients; lawns and streets were the largest sources of phosphorus in residential areas (Waschbusch, Selbig and Bannerman, 1999). The cumulative contribution from many lawns to the amount of nutrients in lakes is not well understood and potentially could be a large part of the total nutrient contribution.

Contributions to the Nutrient Toolbox: Identifying Drivers, Nutrient Sources, and Attribution of Exceedances

EPA Science Inventory

Nutrients are a leading cause of impairments in the United States, and as a result tools are needed to identify drivers of nutrients and response variables (such as chlorophyll a), nutrient sources, and identify causes of exceedances of water quality thresholds. This presentatio...

Neuronal Calcium Signaling in Metabolic Regulation and Adaptation to Nutrient Stress.

PubMed

Jayakumar, Siddharth; Hasan, Gaiti

2018-01-01

All organisms can respond physiologically and behaviorally to environmental fluxes in nutrient levels. Different nutrient sensing pathways exist for specific metabolites, and their inputs ultimately define appropriate nutrient uptake and metabolic homeostasis. Nutrient sensing mechanisms at the cellular level require pathways such as insulin and target of rapamycin (TOR) signaling that integrates information from different organ systems like the fat body and the gut. Such integration is essential for coordinating growth with development. Here we review the role of a newly identified set of integrative interneurons and the role of intracellular calcium signaling within these neurons, in regulating nutrient sensing under conditions of nutrient stress. A comparison of the identified Drosophila circuit and cellular mechanisms employed in this circuit, with vertebrate systems, suggests that the identified cell signaling mechanisms may be conserved for neural circuit function related to nutrient sensing by central neurons. The ideas proposed are potentially relevant for understanding the molecular basis of metabolic disorders, because these are frequently linked to nutritional stress.

Nutrient Tracking Tool - A user-friendly tool for evaluating the water and air quality and quantity as affected by various agricultural management practices

NASA Astrophysics Data System (ADS)

Saleh, A.; Niraula, R.; Gallego, O.; Osei, E.; Kannan, N.

2017-12-01

The Nutrient Tracking Tool (NTT) is a user-friendly web-based computer program that estimate nutrient (nitrogen and phosphorus) and sediment losses from fields managed under a variety of cropping patterns and management practices. The NTT includes a user-friendly web-based interface and is linked to the Agricultural Policy Environmental eXtender (APEX) model. It also accesses USDA-NRCS's Web Soil Survey to obtain field, weather, and soil information. NTT provides producers, government officials, and other users with a fast and efficient method of estimating the nutrient, sediment, and atmosphoric gases (N2o, Co2, and NH4) losses, and crop production under different conservation practices regims at the farm-level. The information obtained from NTT can help producers to determine the most cost-effective conservation practice(s) to reduce the nutrient and sediment losses while optimizing the crop production. Also, the recent version of NTT (NTTg3) has been developed for those coutries without access to national databasis, such as soils and wether. The NTTg3 also has been designed as easy to use APEX interface. NTT is currently being evaluated for trading and other programs at Cheaseapea Bay regions and numerous states in US. During this presentation the new capabilities of NTTg3 will be described and demonstrated.

A simple approach to distinguish land-use and climate-change effects on watershed hydrology

USGS Publications Warehouse

Tomer, M.D.; Schilling, K.E.

2009-01-01

Impacts of climate change on watershed hydrology are subtle compared to cycles of drought and surplus precipitation (PPT), and difficult to separate from effects of land-use change. In the US Midwest, increasing baseflow has been more attributed to increased annual cropping than climate change. The agricultural changes have led to increased fertilizer use and nutrient losses, contributing to Gulf of Mexico hypoxia. In a 25-yr, small-watershed experiment in Iowa, when annual hydrologic budgets were accrued between droughts, a coupled water-energy budget (ecohydrologic) analysis showed effects of tillage and climate on hydrology could be distinguished. The fraction of PPT discharged increased with conservation tillage and time. However, unsatisfied evaporative demand (PET - Hargreaves method) increased under conservation tillage, but decreased with time. A conceptual model was developed and a similar analysis conducted on long-term (>1920s) records from four large, agricultural Midwest watersheds underlain by fine-grained tills. At least three of four watersheds showed decreases in PET, and increases in PPT, discharge, baseflow and PPT:PET ratios (p < 0.10). An analysis of covariance showed the fraction of precipitation discharged increased, while unsatisfied evaporative demand decreased with time among the four watersheds (p < 0.001). Within watersheds, agricultural changes were associated with ecohydrologic shifts that affected timing and significance, but not direction, of these trends. Thus, an ecohydrologic concept derived from small-watershed research, when regionally applied, suggests climate change has increased discharge from Midwest watersheds, especially since the 1970s. By inference, climate change has increased susceptibility of nutrients to water transport, exacerbating Gulf of Mexico hypoxia.

Nutrition of mangroves.

PubMed

Reef, Ruth; Feller, Ilka C; Lovelock, Catherine E

2010-09-01

Mangrove forests dominate the world's tropical and subtropical coastlines. Similar to other plant communities, nutrient availability is one of the major factors influencing mangrove forest structure and productivity. Many mangrove soils have extremely low nutrient availability, although nutrient availability can vary greatly among and within mangrove forests. Nutrient-conserving processes in mangroves are well developed and include evergreeness, resorption of nutrients prior to leaf fall, the immobilization of nutrients in leaf litter during decomposition, high root/shoot ratios and the repeated use of old root channels. Both nitrogen-use efficiency and nutrient resorption efficiencies in mangroves are amongst the highest recorded for angiosperms. A complex range of interacting abiotic and biotic factors controls the availability of nutrients to mangrove trees, and mangroves are characteristically plastic in their ability to opportunistically utilize nutrients when these become available. Nitrogen and phosphorus have been implicated as the nutrients most likely to limit growth in mangroves. Ammonium is the primary form of nitrogen in mangrove soils, in part as a result of anoxic soil conditions, and tree growth is supported mainly by ammonium uptake. Nutrient enrichment is a major threat to marine ecosystems. Although mangroves have been proposed to protect the marine environment from land-derived nutrient pollution, nutrient enrichment can have negative consequences for mangrove forests and their capacity for retention of nutrients may be limited.

Internal cycling, not external loading, decides the nutrient limitation in eutrophic lake: A dynamic model with temporal Bayesian hierarchical inference.

PubMed

Wu, Zhen; Liu, Yong; Liang, Zhongyao; Wu, Sifeng; Guo, Huaicheng

2017-06-01

Lake eutrophication is associated with excessive anthropogenic nutrients (mainly nitrogen (N) and phosphorus (P)) and unobserved internal nutrient cycling. Despite the advances in understanding the role of external loadings, the contribution of internal nutrient cycling is still an open question. A dynamic mass-balance model was developed to simulate and measure the contributions of internal cycling and external loading. It was based on the temporal Bayesian Hierarchical Framework (BHM), where we explored the seasonal patterns in the dynamics of nutrient cycling processes and the limitation of N and P on phytoplankton growth in hyper-eutrophic Lake Dianchi, China. The dynamic patterns of the five state variables (Chla, TP, ammonia, nitrate and organic N) were simulated based on the model. Five parameters (algae growth rate, sediment exchange rate of N and P, nitrification rate and denitrification rate) were estimated based on BHM. The model provided a good fit to observations. Our model results highlighted the role of internal cycling of N and P in Lake Dianchi. The internal cycling processes contributed more than external loading to the N and P changes in the water column. Further insights into the nutrient limitation analysis indicated that the sediment exchange of P determined the P limitation. Allowing for the contribution of denitrification to N removal, N was the more limiting nutrient in most of the time, however, P was the more important nutrient for eutrophication management. For Lake Dianchi, it would not be possible to recover solely by reducing the external watershed nutrient load; the mechanisms of internal cycling should also be considered as an approach to inhibit the release of sediments and to enhance denitrification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Variation in wood nutrients along a tropical soil fertility gradient.

PubMed

Heineman, Katherine D; Turner, Benjamin L; Dalling, James W

2016-07-01

Wood contains the majority of the nutrients in tropical trees, yet controls over wood nutrient concentrations and their function are poorly understood. We measured wood nutrient concentrations in 106 tree species in 10 forest plots spanning a regional fertility gradient in Panama. For a subset of species, we quantified foliar nutrients and wood density to test whether wood nutrients scale with foliar nutrients at the species level, or wood nutrient storage increases with wood density as predicted by the wood economics spectrum. Wood nutrient concentrations varied enormously among species from fourfold in nitrogen (N) to > 30-fold in calcium (Ca), potassium (K), magnesium (Mg) and phosphorus (P). Community-weighted mean wood nutrient concentrations correlated positively with soil Ca, K, Mg and P concentrations. Wood nutrients scaled positively with leaf nutrients, supporting the hypothesis that nutrient allocation is conserved across plant organs. Wood P was most sensitive to variation in soil nutrient availability, and significant radial declines in wood P indicated that tropical trees retranslocate P as sapwood transitions to heartwood. Wood P decreased with increasing wood density, suggesting that low wood P and dense wood are traits associated with tree species persistence on low fertility soils. Substantial variation among species and communities in wood nutrient concentrations suggests that allocation of nutrients to wood, especially P, influences species distributions and nutrient dynamics in tropical forests. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Soil redistribution and nutrient delivery in a Mediterranean rain-fed agro-ecosystem with different crops and management: environmental and economic aspects

NASA Astrophysics Data System (ADS)

López-Vicente, Manuel; Álvarez, Sara

2017-04-01

Mediterranean agro-ecosystems are characterised by fragmented fields and patched vegetation. This shape governs the spatial patterns of water, soil and nutrient redistribution. Rainfall parameters, human infrastructures, crop management, support practices, and land use changes (set aside crops, land abandonment) control the magnitude of these processes. Under rain-fed water supply conditions, runoff generation and soil water content are two important factors in determining crop yield. Soil erosion and nutrient delivery are two of the factors which limit crop yield and thus, the gross earning of the landowner. In hilly landscapes, farmers usually supply extra soil to fill in the ephemeral gullies, and nutrient replenishment with fertilizers is a common practice. The aim of this study is to evaluate the environmental (runoff yield, soil erosion and nutrient delivery) and economic (replenishment of soil and nutrient losses with new soil and fertilizers) consequences of different conventional and conservative practices (fallow/crop rotation, cover crops, land abandonment, buffer strips) in a Mediterranean rain-fed agro-ecosystem (27 ha) with vineyards, cereal crops, cultivated and abandoned olive orchards, several trails and patches of natural vegetation. The five winter cereal fields (wheat and barley) follow fallow/crop rotation. The four vineyards are devoted to the Garnacha variety: one planted in 2007 with white wine grapes, and three planted in 2008 with red wine grapes. The inter-crop strips are managed with a mixture of plant species as cover crop (CC), including: i) spontaneous vegetation, and ii) plantation of common sainfoin (Onobrychis viciifolia). The maintenance of the CC includes one mowing pass at the end of spring, between May and June. The appearance and development of ephemeral gullies and the deposition of soil at the bottom of the hillslope are two of the main concerns of the landowners. In some places, the accumulation of soil complicates grape harvest operations with machinery, forcing manual labour. A total of 222 soil samples were collected in 74 points, and some physical (coarse fragments, effective volume, bulk density, texture, infiltration, etc.) and chemical (soil organic carbon - SOC, total nitrogen, phosphorous and potassium) parameters analysed. The highest values of SOC and TN were found in the forestry (4.64% and 0.198%) and abandoned soils (2.96% and 0.132%), whereas the highest values of TP appeared in the cereal, olive and vineyards (458.4, 458.0 and 440.3 mg / kg P). The highest content of TK appeared in the vineyards (1979.1 mg / kg K), especially in the grapevine strips (2188.3 mg / kg K), due to the fertilizer supply. In order to assess the water, soil and nutrient budgets, four buried sediment traps were installed near the bottom and before reaching the depositional-prone area. The upslope contributing areas of the traps are not nested. Monitoring the magnitude of runoff and sediment yield and the chemical composition of the collected samples allowed calculating the economic cost of water, soil and nutrient losses. The results of this study have implications for other rain-fed productive agro-ecosystems as well as where conservative practices may reduce the economic cost of farmland management.

Aeolian dust nutrient contributions increase with substrate age in semi-arid ecosystems

NASA Astrophysics Data System (ADS)

Coble, A. A.; Hart, S. C.; Ketterer, M. E.; Newman, G. S.

2013-12-01

Rock-derived nutrients supplied by mineral weathering become depleted over time, and without an additional nutrient source the ecosystem may eventually regress or reach a terminal steady state. Previous studies have demonstrated that aeolian dust act as parent materials of soils and important nutrients to plants in arid regions, but the relative importance of these exogenous nutrients to the function of dry ecosystems during soil development is uncertain. Here, using strontium isotopes as a tracer and a well-constrained, three million year old substrate age gradient, we show that aeolian-derived nutrients become increasingly important to plant-available soil pools and tree (Pinus edulis) growth during the latter stages of soil development in a semi-arid climate. Furthermore, the depth of nutrient uptake increased on older substrates, suggesting that trees in arid regions acquire nutrients from greater depths as ecosystem development progresses presumably in response to nutrient depletion in the more weathered surface soils. Our results contribute to the unification of biogeochemical theory by demonstrating the similarity in roles of atmospheric nutrient inputs during ecosystem development across contrasting climates.

Trends in Dietary Supplement Use in a Cohort of Postmenopausal Women From Iowa

PubMed Central

Park, Kyong; Jacobs, David R.

2009-01-01

Although it is widely known that use of dietary supplements is common in the United States, little is known about use patterns among older Americans. The authors examined trends in dietary supplement use and its contribution to total nutrient intake in the Iowa Women's Health Study cohort in 1986 (baseline) and 2004 (follow-up). The proportion of women who reported using dietary supplements increased substantially between baseline (66%) and follow-up (85%). Moreover, a substantial proportion of women reported using multiple dietary supplements, with 27% using 4 or more products in 2004. Dietary supplements contributed substantially to total intake of many nutrients at baseline, and their contribution became relatively greater at follow-up for most nutrients examined. For most nutrients, no decline in intake was observed, as might have been expected in an aging cohort. Rather, intake of many nutrients increased, primarily because of the rising use of dietary supplements. Use of dietary supplements by older individuals is of particular importance because of the potential benefits of maintaining nutrient intake levels despite potentially declining food intake. However, possible risks from obtaining a large proportion of purified nutrients from dietary supplements rather than deriving them from foods should be studied. PMID:19208725

Manure and residue inputs maintained SOC in conservation production systems in the Upper Midwest

USDA-ARS?s Scientific Manuscript database

Conservation production systems are needed in the upper Midwest to slow down soil and nutrient loss through tillage-induced erosion. However, due to the cool, wet climate, producers are reluctant to adapt no-till strategies. With focus on strip-tillage (ST) and a diverse four-year crop rotation (4y...

Repeated use of ion-exchange resin membranes in calcareous soils

USGS Publications Warehouse

Sherrod, S.K.; Belnap, Jayne; Miller, M.E.

2003-01-01

This study compared the consistency of nutrient extraction among repeated cycles of ion-exchange resin membrane use. Two sandy calcareous soils and different equilibration temperatures were tested. No single nutrient retained consistent values from cycle to cycle in all treatments, although both soil source and temperature conferred some influence. It was concluded that the most conservative use of resin membranes is single-use.

Periphytic biofilms: A promising nutrient utilization regulator in wetlands.

PubMed

Wu, Yonghong; Liu, Junzhuo; Rene, Eldon R

2018-01-01

Low nutrient utilization efficiency in agricultural ecosystems is the main cause of nonpoint source (NPS) pollution. Therefore, novel approaches should be explored to improve nutrient utilization in these ecosystems. Periphytic biofilms composed of microalgae, bacteria and other microbial organisms are ubiquitous and form a 'third phase' in artificial wetlands such as paddy fields. Periphytic biofilms play critical roles in nutrient transformation between the overlying water and soil/sediment, however, their contributions to nutrient utilization improvement and NPS pollution control have been largely underestimated. This mini review summarizes the contributions of periphytic biofilms to nutrient transformation processes, including assimilating and storing bioavailable nitrogen and phosphorus, fixing nitrogen, and activating occluded phosphorus. Future research should focus on augmenting the nitrogen fixing, phosphate solubilizing and phosphatase producing microorganisms in periphytic biofilms to improve nutrient utilization and thereby reduce NPS pollution production in artificial and natural wetland ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using high-frequency sensors to identify hydroclimatological controls on storm-event variability in catchment nutrient fluxes and source zone activation

NASA Astrophysics Data System (ADS)

Blaen, Phillip; Khamis, Kieran; Lloyd, Charlotte; Krause, Stefan

2017-04-01

At the river catchment scale, storm events can drive highly variable behaviour in nutrient and water fluxes, yet short-term dynamics are frequently missed by low resolution sampling regimes. In addition, nutrient source contributions can vary significantly within and between storm events. Our inability to identify and characterise time dynamic source zone contributions severely hampers the adequate design of land use management practices in order to control nutrient exports from agricultural landscapes. Here, we utilise an 8-month high-frequency (hourly) time series of streamflow, nitrate concentration (NO3) and fluorescent dissolved organic matter concentration (FDOM) derived from optical in-situ sensors located in a headwater agricultural catchment. We characterised variability in flow and nutrient dynamics across 29 storm events. Storm events represented 31% of the time series and contributed disproportionately to nutrient loads (43% of NO3 and 36% of CDOM) relative to their duration. Principal components analysis of potential hydroclimatological controls on nutrient fluxes demonstrated that a small number of components, representing >90% of variance in the dataset, were highly significant model predictors of inter-event variability in catchment nutrient export. Hysteresis analysis of nutrient concentration-discharge relationships suggested spatially discrete source zones existed for NO3 and FDOM, and that activation of these zones varied on an event-specific basis. Our results highlight the benefits of high-frequency in-situ monitoring for characterising complex short-term nutrient dynamics and unravelling connections between hydroclimatological variability and river nutrient export and source zone activation under extreme flow conditions. These new process-based insights are fundamental to underpinning the development of targeted management measures to reduce nutrient loading of surface waters.

Nutrient Contents of the Freshwater Crab, Isolapotamon bauense from Sarawak, Malaysia (Borneo)

PubMed Central

Grinang, Jongkar; Tyan, Pang Sing; Tuen, Andrew Alek; Das, Indraneil

2017-01-01

Data on nutrient contents of freshwater crabs are important for ecological studies and species conservation assessments, especially when the species concerned is threatened among others by habitat destruction and uncontrolled resources utilisation. Indeed comprehensive biological information is required to reconcile the needs between sustainable resources utilisation and conservation of the species. This study documents the nutrient contents of a freshwater crab, Isolapotamon bauense which is listed as ‘Vulnerable’ in the IUCN Red List of Threatened Species and also being harvested by local community for dietary supplement. Results show that muscles of the freshwater crab contain a substantial amount of nutrients in particular water content (male = 79.31 ± 2.30 %, female = 77.63 ± 0.56 %), protein (male = 77.47 ± 6.11 %, female = 63.28 ± 3.62 %), magnesium (male = 51.48 ± 16.10 mg/g, female = 39.73 ± 6.99 mg/g) and calcium (male = 25.50 ± 6.98 mg/g, female = 39.73 ± 6.99 mg/g). Means of nutrient contents between male and female crabs are not significantly different. It is estimated that an individual of I. bauense with weight range of 56–139 g contained on average of 0.35 ± 0.15 g of protein. Our estimation also shows that the number of individuals of the freshwater crab required to meet the recommended daily protein intakes of the community concerned is in the range 35–96 individuals for children, 130–188 individuals for adolescents, 171–179 individuals for men and 149–159 individuals for women. The results imply that harvesting of wild I. bauense as a source of protein supplement naturally may not be practical because of its relatively low population abundance, and conservation of the species for its ecological roles may thus be preferred. PMID:28890762

Nutrient patterns and their food sources in an International Study Setting: report from the EPIC study.

PubMed

Moskal, Aurelie; Pisa, Pedro T; Ferrari, Pietro; Byrnes, Graham; Freisling, Heinz; Boutron-Ruault, Marie-Christine; Cadeau, Claire; Nailler, Laura; Wendt, Andrea; Kühn, Tilman; Boeing, Heiner; Buijsse, Brian; Tjønneland, Anne; Halkjær, Jytte; Dahm, Christina C; Chiuve, Stephanie E; Quirós, Jose R; Buckland, Genevieve; Molina-Montes, Esther; Amiano, Pilar; Huerta Castaño, José M; Gurrea, Aurelio Barricarte; Khaw, Kay-Tee; Lentjes, Marleen A; Key, Timothy J; Romaguera, Dora; Vergnaud, Anne-Claire; Trichopoulou, Antonia; Bamia, Christina; Orfanos, Philippos; Palli, Domenico; Pala, Valeria; Tumino, Rosario; Sacerdote, Carlotta; de Magistris, Maria Santucci; Bueno-de-Mesquita, H Bas; Ocké, Marga C; Beulens, Joline W J; Ericson, Ulrika; Drake, Isabel; Nilsson, Lena M; Winkvist, Anna; Weiderpass, Elisabete; Hjartåker, Anette; Riboli, Elio; Slimani, Nadia

2014-01-01

Compared to food patterns, nutrient patterns have been rarely used particularly at international level. We studied, in the context of a multi-center study with heterogeneous data, the methodological challenges regarding pattern analyses. We identified nutrient patterns from food frequency questionnaires (FFQ) in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study and used 24-hour dietary recall (24-HDR) data to validate and describe the nutrient patterns and their related food sources. Associations between lifestyle factors and the nutrient patterns were also examined. Principal component analysis (PCA) was applied on 23 nutrients derived from country-specific FFQ combining data from all EPIC centers (N = 477,312). Harmonized 24-HDRs available for a representative sample of the EPIC populations (N = 34,436) provided accurate mean group estimates of nutrients and foods by quintiles of pattern scores, presented graphically. An overall PCA combining all data captured a good proportion of the variance explained in each EPIC center. Four nutrient patterns were identified explaining 67% of the total variance: Principle component (PC) 1 was characterized by a high contribution of nutrients from plant food sources and a low contribution of nutrients from animal food sources; PC2 by a high contribution of micro-nutrients and proteins; PC3 was characterized by polyunsaturated fatty acids and vitamin D; PC4 was characterized by calcium, proteins, riboflavin, and phosphorus. The nutrients with high loadings on a particular pattern as derived from country-specific FFQ also showed high deviations in their mean EPIC intakes by quintiles of pattern scores when estimated from 24-HDR. Center and energy intake explained most of the variability in pattern scores. The use of 24-HDR enabled internal validation and facilitated the interpretation of the nutrient patterns derived from FFQs in term of food sources. These outcomes open research opportunities and perspectives of using nutrient patterns in future studies particularly at international level.

Neurodegeneration from mitochondrial insufficiency: nutrients, stem cells, growth factors, and prospects for brain rebuilding using integrative management.

PubMed

Kidd, Parris M

2005-12-01

Degenerative brain disorders (neurodegeneration) can be frustrating for both conventional and alternative practitioners. A more comprehensive, integrative approach is urgently needed. One emerging focus for intervention is brain energetics. Specifically, mitochondrial insufficiency contributes to the etiopathology of many such disorders. Electron leakages inherent to mitochondrial energetics generate reactive oxygen free radical species that may place the ultimate limit on lifespan. Exogenous toxins, such as mercury and other environmental contaminants, exacerbate mitochondrial electron leakage, hastening their demise and that of their host cells. Studies of the brain in Alzheimer's and other dementias, Down syndrome, stroke, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, Friedreich's ataxia, aging, and constitutive disorders demonstrate impairments of the mitochondrial citric acid cycle and oxidative phosphorylation (OXPHOS) enzymes. Imaging or metabolic assays frequently reveal energetic insufficiency and depleted energy reserve in brain tissue in situ. Orthomolecular nutrients involved in mitochondrial metabolism provide clinical benefit. Among these are the essential minerals and the B vitamin group; vitamins E and K; and the antioxidant and energetic cofactors alpha-lipoic acid (ALA), ubiquinone (coenzyme Q10; CoQ10), and nicotinamide adenine dinucleotide, reduced (NADH). Recent advances in the area of stem cells and growth factors encourage optimism regarding brain regeneration. The trophic nutrients acetyl L-carnitine (ALCAR), glycerophosphocholine (GPC), and phosphatidylserine (PS) provide mitochondrial support and conserve growth factor receptors; all three improved cognition in double-blind trials. The omega-3 fatty acid docosahexaenoic acid (DHA) is enzymatically combined with GPC and PS to form membrane phospholipids for nerve cell expansion. Practical recommendations are presented for integrating these safe and well-tolerated orthomolecular nutrients into a comprehensive dietary supplementation program for brain vitality and productive lifespan.

Nutrient and algal responses to winterkilled fish-derived nutrient subsidies in eutrophic lakes

USGS Publications Warehouse

Schoenebeck, Casey W.; Brown, Michael L.; Chipps, Steven R.; German, David R.

2012-01-01

Fishes inhabiting shallow, glacial lakes of the Prairie Pothole Region in the United States and Canada periodically experience hypoxia in severe winters that can lead to extensive fish mortality resulting in high biomasses of dead fish. However, the role of carcass-derived nutrient subsidies in shallow, eutrophic lakes translocated to pelagic primary producers is not well documented. This study quantified the influence of winterkill events on nutrient contributions from decaying fish carcasses of common carp (Cyprinus carpio) and the phytoplankton response among pre- and postwinterkill years and compared seasonal patterns of nutrient limitation and phytoplankton community composition between winterkill and nonwinterkill lakes. We found that fish carcasses contributed an estimated 2.5–4.3 kg/ha of total (Kjeldahl) nitrogen (N) and 0.3–0.5 kg/ha of total phosphorus (P) to lakes that experienced winterkill conditions. Nutrient bioassays showed that winterkill lakes were primarily N limited, congruent with the low N:P ratios produced by fish carcasses corrected for the disproportionate release of N and P (8.6). Nutrient subsidies translocated from decomposed fish to pelagic primary producers seemed to have little immediate influence on the seasonal phytoplankton community composition, but total N and subsequent chlorophyll-a increased the year following the winterkill event. Cyanobacteria density varied seasonally but was higher in winterkill lakes, presumably due to the integration of nutrients released from fish decomposition. This study provides evidence that large inputs of autochthonous fish-derived nutrients contribute to nutrient availability within winterkilled systems and increase the maximum attainable biomass of the phytoplankton community.

Fat body remodeling and homeostasis control in Drosophila.

PubMed

Zheng, Huimei; Yang, Xiaohang; Xi, Yongmei

2016-12-15

Remarkable advances have been made in recent years in our understanding of the Drosophila fat body and its functions in energy storage, immune response and nutrient sensing. The fat body interplays with other tissues to respond to the physiological needs of the body's growth and coordinates various metabolic processes at different developmental stages and under different environmental conditions. The identification of various conserved genetic functions and signaling pathways relating to the Drosophila fat body may provide clues to lipometabolic disease and other aspects of tissue remodeling in humans. Here, we discuss recent insights into how regulation of fat body remodeling contributes to hemostasis with a special focus on how signaling networks and internal physiological states shape different aspects of the lipid metabolism in Drosophila. Copyright © 2016. Published by Elsevier Inc.

Vulnerability Assessment of Groundwater Resources by Nutrient Source Apportionment to Individual Groundwater Wells: A Case Study in North Carolina

NASA Astrophysics Data System (ADS)

Ayub, R.; Obenour, D. R.; Keyworth, A. J.; Genereux, D. P.; Mahinthakumar, K.

2016-12-01

Groundwater contamination by nutrients (nitrogen and phosphorus) is a major concern in water table aquifers that underlie agricultural areas in the mid-Atlantic Coastal Plain of the United States. High nutrient concentrations leaching into shallow groundwater can lead to human health problems and eutrophication of receiving surface waters. Liquid manure from concentrated animal feeding operations (CAFOs) stored in open-air lagoons and applied to spray fields can be a significant source of nutrients to groundwater, along with septic waste. In this study, we developed a model-based methodology for source apportionment and vulnerability assessment using sparse groundwater quality sampling measurements for Duplin County, North Carolina (NC), obtained by the NC Department of Environmental Quality (NC DEQ). This model provides information relevant to management by estimating the nutrient transport through the aquifer from different sources and addressing the uncertainty of nutrient contaminant propagation. First, the zones of influence (dependent on nutrient pathways) for individual groundwater monitoring wells were identified using a two-dimensional vertically averaged groundwater flow and transport model incorporating geologic uncertainty for the surficial aquifer system. A multiple linear regression approach is then applied to estimate the contribution weights for different nutrient source types using the nutrient measurements from monitoring wells and the potential sources within each zone of influence. Using the source contribution weights and their uncertainty, a probabilistic vulnerability assessment of the study area due to nutrient contamination is performed. Knowledge of the contribution of different nutrient sources to contamination at receptor locations (e.g., private wells, municipal wells, stream beds etc.) will be helpful in planning and implementation of appropriate mitigation measures.

Winter nutrient behaviours in the Pearl River estuary

NASA Astrophysics Data System (ADS)

Wang, G.; Jin, S.; Du, M.

2017-12-01

Nutrient (nitrate, nitrite, ammonium, phosphate, and silicate) mapping and time-series investigation were carried out in winter in the Pearl River estuary, China. These nutrients behaved non-conservatively in the upper estuary. In the middle and lower estuary, however, nitrate and silicate seemed to be controled by physical mixing, while additions of nitrite, ammonium, and phosphate were found in the middle estuary. Nitrate was the dominant disslved inorganic nitrogen, with a fraction of more than 2/3. From the upper to the lower estuary the N:P ratio decreased from more than 200 to near the Redfield ratio of 16. Nutrients near the surface behaved almost the same as near the bottom in the water column at both the uppper and lower estuary. During a tidal cycle these nutrients seemed to be regulated more by physical mixing than by other processes.

Effect of nutrient enrichment on the source and composition of sediment organic carbon in tropical seagrass beds in the South China Sea.

PubMed

Liu, Songlin; Jiang, Zhijian; Zhang, Jingping; Wu, Yunchao; Lian, Zhonglian; Huang, Xiaoping

2016-09-15

To assess the effect of nutrient enrichment on the source and composition of sediment organic carbon (SOC) beneath Thalassia hemprichii and Enhalus acoroides in tropical seagrass beds, Xincun Bay, South China Sea, intertidal sediment, primary producers, and seawater samples were collected. No significant differences on sediment δ(13)C, SOC, and microbial biomass carbon (MBC) were observed between T. hemprichii and E. acoroides. SOC was mainly of autochthonous origin, while the contribution of seagrass to SOC was less than that of suspended particulate organic matter, macroalgae and epiphytes. High nutrient concentrations contributed substantially to SOC of seagrass, macroalgae, and epiphytes. The SOC, MBC, and MBC/SOC ratio in the nearest transect to fish farming were the highest. This suggested a more labile composition of SOC and shorter turnover times in higher nutrient regions. Therefore, the research indicates that nutrient enrichment could enhance plant-derived contributions to SOC and microbial use efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Invasive Acer negundo outperforms native species in non-limiting resource environments due to its higher phenotypic plasticity

PubMed Central

2011-01-01

Background To identify the determinants of invasiveness, comparisons of traits of invasive and native species are commonly performed. Invasiveness is generally linked to higher values of reproductive, physiological and growth-related traits of the invasives relative to the natives in the introduced range. Phenotypic plasticity of these traits has also been cited to increase the success of invasive species but has been little studied in invasive tree species. In a greenhouse experiment, we compared ecophysiological traits between an invasive species to Europe, Acer negundo, and early- and late-successional co-occurring native species, under different light, nutrient availability and disturbance regimes. We also compared species of the same species groups in situ, in riparian forests. Results Under non-limiting resources, A. negundo seedlings showed higher growth rates than the native species. However, A. negundo displayed equivalent or lower photosynthetic capacities and nitrogen content per unit leaf area compared to the native species; these findings were observed both on the seedlings in the greenhouse experiment and on adult trees in situ. These physiological traits were mostly conservative along the different light, nutrient and disturbance environments. Overall, under non-limiting light and nutrient conditions, specific leaf area and total leaf area of A. negundo were substantially larger. The invasive species presented a higher plasticity in allocation to foliage and therefore in growth with increasing nutrient and light availability relative to the native species. Conclusions The higher level of plasticity of the invasive species in foliage allocation in response to light and nutrient availability induced a better growth in non-limiting resource environments. These results give us more elements on the invasiveness of A. negundo and suggest that such behaviour could explain the ability of A. negundo to outperform native tree species, contributes to its spread in European resource-rich riparian forests and impedes its establishment under closed-canopy hardwood forests. PMID:22115342

Dietary Supplements Contribute Substantially to the Total Nutrient Intake in Pregnant Norwegian Women

PubMed Central

Haugen, Margaretha; Brantsæter, Anne Lise; Alexander, Jan; Meltzer, Helle Margrete

2008-01-01

Background Use of dietary supplements during pregnancy may give an important contribution to nutrient intake, and for nutrients like folate and vitamin D supplements are recommended. Our objective was to study use and contribution of dietary supplement to nutrient intake among women participating in the Norwegian Mother and Child Cohort Study (MoBa). Methods This study is based on 40,108 women participating in MoBa which is conducted by the Norwegian Institute of Public Health. The women had filled inversion 2 of the food frequency questionnaire in MoBa between February 2002 and February 2005. Results 81% reported use of one or more dietary supplements. The most commonly used category was cod liver oil/fish oil supplements (59%) followed by singular folic acid supplements (36%) and multivitamin/multimineral supplements (31%). The nutrient contribution of the dietary supplements varied from 65% for folate and vitamin D to 1% for potassium among supplement users. The dietary intake of vitamin D, folate, iodine and iron did not reach the Nordic Recommendations for pregnant women. Conclusions Use of supplements improved the intake of folate, iron and vitamin D, but not sufficiently to reach the recommended amounts. PMID:18645244

Increased plant growth from nitrogen addition should conserve phosphorus in terrestrial ecosystems.

PubMed

Perring, Michael P; Hedin, Lars O; Levin, Simon A; McGroddy, Megan; de Mazancourt, Claire

2008-02-12

Inputs of available nitrogen (N) to ecosystems have grown over the recent past. There is limited general understanding of how increased N inputs affect the cycling and retention of other potentially limiting nutrients. Using a plant-soil nutrient model, and by explicitly coupling N and phosphorus (P) in plant biomass, we examine the impact of increasing N supply on the ecosystem cycling and retention of P, assuming that the main impact of N is to increase plant growth. We find divergent responses in the P cycle depending on the specific pathway by which nutrients are lost from the ecosystem. Retention of P is promoted if the relative propensity for loss of plant available P is greater than that for the loss of less readily available organic P. This is the first theoretical demonstration that the coupled response of ecosystem-scale nutrient cycles critically depends on the form of nutrient loss. P retention might be lessened, or reversed, depending on the kinetics and size of a buffering reactive P pool. These properties determine the reactive pool's ability to supply available P. Parameterization of the model across a range of forest ecosystems spanning various environmental and climatic conditions indicates that enhanced plant growth due to increased N should trigger increased P conservation within ecosystems while leading to more dissolved organic P loss. We discuss how the magnitude and direction of the effect of N may also depend on other processes.

Development Strategy for Effective Sampling to Detect Possible Nutrient Fluxes in Oligotrophic Coastal Reef Waters in the Caribbean

DTIC Science & Technology

2009-01-01

catastrophic events (eg, hurricanes, tsuna- mis, floodings, harmful algal blooms and coral bleachings ). These changes have been known to jeopardise the...SUPPLEMENTARY NOTES 20090814035 14. ABSTRACT The stress contributed by nutrients to the coral reef ecosystem is among many problems that may be resolved using...Rosenstiel School of Marine and Atmospheric Science, University of Miami The stress contributed by nutrients to the coral reef ecosystem is among many

Effects of nutrient load on microbial activities within a seagrass-dominated ecosystem: Implications of changes in seagrass blue carbon.

PubMed

Liu, Songlin; Jiang, Zhijian; Wu, Yunchao; Zhang, Jingping; Arbi, Iman; Ye, Feng; Huang, Xiaoping; Macreadie, Peter Ian

2017-04-15

Nutrient loading is a leading cause of global seagrass decline, triggering shifts from seagrass- to macroalgal-dominance. Within seagrass meadows of Xincun Bay (South China Sea), we found that nutrient loading (due to fish farming) increased sediment microbial biomass and extracellular enzyme activity associated with carbon cycling (polyphenol oxidase, invertase and cellulase), with a corresponding decrease in percent sediment organic carbon (SOC), suggesting that nutrients primed microorganism and stimulated SOC remineralization. Surpisingly, however, the relative contribution of seagrass-derived carbon to bacteria (δ 13 C bacteria ) increased with nutrient loading, despite popular theory being that microbes switch to consuming macroalgae which are assumed to provide a more labile carbon source. Organic carbon sources of fungi were unaffected by nutrient loading. Overall, this study suggests that nutrient loading changes the relative contribution of seagrass and algal sources to SOC pools, boosting sediment microbial biomass and extracellular enzyme activity, thereby possibly changing seagrass blue carbon. Copyright © 2017 Elsevier Ltd. All rights reserved.

Engineering crop nutrient efficiency for sustainable agriculture.

PubMed

Chen, Liyu; Liao, Hong

2017-10-01

Increasing crop yields can provide food, animal feed, bioenergy feedstocks and biomaterials to meet increasing global demand; however, the methods used to increase yield can negatively affect sustainability. For example, application of excess fertilizer can generate and maintain high yields but also increases input costs and contributes to environmental damage through eutrophication, soil acidification and air pollution. Improving crop nutrient efficiency can improve agricultural sustainability by increasing yield while decreasing input costs and harmful environmental effects. Here, we review the mechanisms of nutrient efficiency (primarily for nitrogen, phosphorus, potassium and iron) and breeding strategies for improving this trait, along with the role of regulation of gene expression in enhancing crop nutrient efficiency to increase yields. We focus on the importance of root system architecture to improve nutrient acquisition efficiency, as well as the contributions of mineral translocation, remobilization and metabolic efficiency to nutrient utilization efficiency. © 2017 Institute of Botany, Chinese Academy of Sciences.

Hopanoids play a role in stress tolerance and nutrient storage in the cyanobacterium Nostoc punctiforme.

PubMed

Ricci, J N; Morton, R; Kulkarni, G; Summers, M L; Newman, D K

2017-01-01

Hopanes are abundant in ancient sedimentary rocks at discrete intervals in Earth history, yet interpreting their significance in the geologic record is complicated by our incomplete knowledge of what their progenitors, hopanoids, do in modern cells. To date, few studies have addressed the breadth of diversity of physiological functions of these lipids and whether those functions are conserved across the hopanoid-producing bacterial phyla. Here, we generated mutants in the filamentous cyanobacterium, Nostoc punctiforme, that are unable to make all hopanoids (shc) or 2-methylhopanoids (hpnP). While the absence of hopanoids impedes growth of vegetative cells at high temperature, the shc mutant grows faster at low temperature. This finding is consistent with hopanoids acting as membrane rigidifiers, a function shared by other hopanoid-producing phyla. Apart from impacting fitness under temperature stress, hopanoids are dispensable for vegetative cells under other stress conditions. However, hopanoids are required for stress tolerance in akinetes, a resting survival cell type. While 2-methylated hopanoids do not appear to contribute to any stress phenotype, total hopanoids and to a lesser extent 2-methylhopanoids were found to promote the formation of cyanophycin granules in akinetes. Finally, although hopanoids support symbiotic interactions between Alphaproteobacteria and plants, they do not appear to facilitate symbiosis between N. punctiforme and the hornwort Anthoceros punctatus. Collectively, these findings support interpreting hopanes as general environmental stress biomarkers. If hopanoid-mediated enhancement of nitrogen-rich storage products turns out to be a conserved phenomenon in other organisms, a better understanding of this relationship may help us parse the enrichment of 2-methylhopanes in the rock record during episodes of disrupted nutrient cycling. © 2016 John Wiley & Sons Ltd.

Metolachlor metabolite (MESA) reveals agricultural nitrate-N fate and transport in Choptank River watershed

USGS Publications Warehouse

McCarty, Gregory W.; Hapeman, Cathleen J.; Rice, Clifford P.; Hively, W. Dean; McConnell, Laura L.; Sadeghi, Ali M.; Lang, Megan W.; Whitall, David R.; Bialek, Krystyna; Downey, Peter

2014-01-01

Over 50% of streams in the Chesapeake Bay watershed have been rated as poor or very poor based on the index of biological integrity. The Choptank River estuary, a Bay tributary on the eastern shore, is one such waterway, where corn and soybean production in upland areas of the watershed contribute significant loads of nutrients and sediment to streams. We adopted a novel approach utilizing the relationship between the concentration of nitrate-N and the stable, water-soluble herbicide degradation product MESA {2-[2-ethyl-N-(1-methoxypropan-2-yl)-6-methylanilino]-2-oxoethanesulfonic acid} to distinguish between dilution and denitrification effects on the stream concentration of nitrate-N in agricultural subwatersheds. The ratio of mean nitrate-N concentration/(mean MESA concentration * 1000) for 15 subwatersheds was examined as a function of percent cropland on hydric soil. This inverse relationship (R2 = 0.65, p 2 ≤ 0.99) for all eight sampling dates except one where R2 = 0.90. This very strong correlation indicates that nitrate-N was conserved in much of the Choptank River estuary, that dilution alone is responsible for the changes in nitrate-N and MESA concentrations, and more importantly nitrate-N loads are not reduced in the estuary prior to entering the Chesapeake Bay. Thus, a critical need exists to minimize nutrient export from agricultural production fields and to identify specific conservation practices to address the hydrologic conditions within each subwatershed. In well drained areas, removal of residual N within the cropland is most critical, and practices such as cover crops which sequester the residual N should be strongly encouraged. In poorly drained areas where denitrification can occur, wetland restoration and controlled drained structures that minimize ditch flow should be used to maximize denitrification.

Water Technology Innovation: 10 Market Opportunities

EPA Pesticide Factsheets

The Water Technology Innovation Blueprint offers an overview of market opportunities that include conserving and recovering energy, recovering nutrients, improving water infrastructure, reducing costs for water monitoring, and improving water quality.

Genome-resolved metaproteomic characterization of preterm infant gut microbiota development reveals species-specific metabolic shifts and variabilities during early life

DOE PAGES

Xiong, Weili; Brown, Christopher T.; Morowitz, Michael J.; ...

2017-07-10

Establishment of the human gut microbiota begins at birth. This early-life microbiota development can impact host physiology during infancy and even across an entire life span. But, the functional stability and population structure of the gut microbiota during initial colonization remain poorly understood. Metaproteomics is an emerging technology for the large-scale characterization of metabolic functions in complex microbial communities (gut microbiota). We applied a metagenome-informed metaproteomic approach to study the temporal and inter-individual differences of metabolic functions during microbial colonization of preterm human infants’ gut. By analyzing 30 individual fecal samples, we identified up to 12,568 protein groups for eachmore » of four infants, including both human and microbial proteins. With genome-resolved matched metagenomics, proteins were confidently identified at the species/strain level. The maximum percentage of the proteome detected for the abundant organisms was ~45%. A time-dependent increase in the relative abundance of microbial versus human proteins suggested increasing microbial colonization during the first few weeks of early life. We observed remarkable variations and temporal shifts in the relative protein abundances of each organism in these preterm gut communities. Given the dissimilarity of the communities, only 81 microbial EggNOG orthologous groups and 57 human proteins were observed across all samples. These conserved microbial proteins were involved in carbohydrate, energy, amino acid and nucleotide metabolism while conserved human proteins were related to immune response and mucosal maturation. We also identified seven proteome clusters for the communities and showed infant gut proteome profiles were unstable across time and not individual-specific. By applying a gut-specific metabolic module (GMM) analysis, we found that gut communities varied primarily in the contribution of nutrient (carbohydrates, lipids, and amino acids) utilization and short-chain fatty acid production. Overall, this study reports species-specific proteome profiles and metabolic functions of human gut microbiota during early colonization. In particular, our work contributes to reveal microbiota-associated shifts and variations in the metabolism of three major nutrient sources and short-chain fatty acid during colonization of preterm infant gut.« less

Genome-resolved metaproteomic characterization of preterm infant gut microbiota development reveals species-specific metabolic shifts and variabilities during early life

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Weili; Brown, Christopher T.; Morowitz, Michael J.

Establishment of the human gut microbiota begins at birth. This early-life microbiota development can impact host physiology during infancy and even across an entire life span. But, the functional stability and population structure of the gut microbiota during initial colonization remain poorly understood. Metaproteomics is an emerging technology for the large-scale characterization of metabolic functions in complex microbial communities (gut microbiota). We applied a metagenome-informed metaproteomic approach to study the temporal and inter-individual differences of metabolic functions during microbial colonization of preterm human infants’ gut. By analyzing 30 individual fecal samples, we identified up to 12,568 protein groups for eachmore » of four infants, including both human and microbial proteins. With genome-resolved matched metagenomics, proteins were confidently identified at the species/strain level. The maximum percentage of the proteome detected for the abundant organisms was ~45%. A time-dependent increase in the relative abundance of microbial versus human proteins suggested increasing microbial colonization during the first few weeks of early life. We observed remarkable variations and temporal shifts in the relative protein abundances of each organism in these preterm gut communities. Given the dissimilarity of the communities, only 81 microbial EggNOG orthologous groups and 57 human proteins were observed across all samples. These conserved microbial proteins were involved in carbohydrate, energy, amino acid and nucleotide metabolism while conserved human proteins were related to immune response and mucosal maturation. We also identified seven proteome clusters for the communities and showed infant gut proteome profiles were unstable across time and not individual-specific. By applying a gut-specific metabolic module (GMM) analysis, we found that gut communities varied primarily in the contribution of nutrient (carbohydrates, lipids, and amino acids) utilization and short-chain fatty acid production. Overall, this study reports species-specific proteome profiles and metabolic functions of human gut microbiota during early colonization. In particular, our work contributes to reveal microbiota-associated shifts and variations in the metabolism of three major nutrient sources and short-chain fatty acid during colonization of preterm infant gut.« less

Genome-resolved metaproteomic characterization of preterm infant gut microbiota development reveals species-specific metabolic shifts and variabilities during early life.

PubMed

Xiong, Weili; Brown, Christopher T; Morowitz, Michael J; Banfield, Jillian F; Hettich, Robert L

2017-07-10

Establishment of the human gut microbiota begins at birth. This early-life microbiota development can impact host physiology during infancy and even across an entire life span. However, the functional stability and population structure of the gut microbiota during initial colonization remain poorly understood. Metaproteomics is an emerging technology for the large-scale characterization of metabolic functions in complex microbial communities (gut microbiota). We applied a metagenome-informed metaproteomic approach to study the temporal and inter-individual differences of metabolic functions during microbial colonization of preterm human infants' gut. By analyzing 30 individual fecal samples, we identified up to 12,568 protein groups for each of four infants, including both human and microbial proteins. With genome-resolved matched metagenomics, proteins were confidently identified at the species/strain level. The maximum percentage of the proteome detected for the abundant organisms was ~45%. A time-dependent increase in the relative abundance of microbial versus human proteins suggested increasing microbial colonization during the first few weeks of early life. We observed remarkable variations and temporal shifts in the relative protein abundances of each organism in these preterm gut communities. Given the dissimilarity of the communities, only 81 microbial EggNOG orthologous groups and 57 human proteins were observed across all samples. These conserved microbial proteins were involved in carbohydrate, energy, amino acid and nucleotide metabolism while conserved human proteins were related to immune response and mucosal maturation. We identified seven proteome clusters for the communities and showed infant gut proteome profiles were unstable across time and not individual-specific. Applying a gut-specific metabolic module (GMM) analysis, we found that gut communities varied primarily in the contribution of nutrient (carbohydrates, lipids, and amino acids) utilization and short-chain fatty acid production. Overall, this study reports species-specific proteome profiles and metabolic functions of human gut microbiota during early colonization. In particular, our work contributes to reveal microbiota-associated shifts and variations in the metabolism of three major nutrient sources and short-chain fatty acid during colonization of preterm infant gut.

Octopamine connects nutrient cues to lipid metabolism upon nutrient deprivation.

PubMed

Tao, Jun; Ma, Yi-Cheng; Yang, Zhong-Shan; Zou, Cheng-Gang; Zhang, Ke-Qin

2016-05-01

Starvation is probably the most common stressful situation in nature. In vertebrates, elevation of the biogenic amine norepinephrine levels is common during starvation. However, the precise role of norepinephrine in nutrient deprivation remains largely unknown. We report that in the free-living nematode Caenorhabditis elegans, up-regulation of the biosynthesis of octopamine, the invertebrate counterpart of norepinephrine, serves as a mechanism to adapt to starvation. During nutrient deprivation, the nuclear receptor DAF-12, known to sense nutritional cues, up-regulates the expression of tbh-1 that encodes tyramine β-hydroxylase, a key enzyme for octopamine biosynthesis, in the RIC neurons. Octopamine induces the expression of the lipase gene lips-6 via its receptor SER-3 in the intestine. LIPS-6, in turn, elicits lipid mobilization. Our findings reveal that octopamine acts as an endocrine regulator linking nutrient cues to lipolysis to maintain energy homeostasis, and suggest that such a mechanism may be evolutionally conserved in diverse organisms.

Fishing down nutrients on coral reefs.

PubMed

Allgeier, Jacob E; Valdivia, Abel; Cox, Courtney; Layman, Craig A

2016-08-16

Fishing is widely considered a leading cause of biodiversity loss in marine environments, but the potential effect on ecosystem processes, such as nutrient fluxes, is less explored. Here, we test how fishing on Caribbean coral reefs influences biodiversity and ecosystem functions provided by the fish community, that is, fish-mediated nutrient capacity. Specifically, we modelled five processes of nutrient storage (in biomass) and supply (via excretion) of nutrients, as well as a measure of their multifunctionality, onto 143 species of coral reef fishes across 110 coral reef fish communities. These communities span a gradient from extreme fishing pressure to protected areas with little to no fishing. We find that in fished sites fish-mediated nutrient capacity is reduced almost 50%, despite no substantial changes in the number of species. Instead, changes in community size and trophic structure were the primary cause of shifts in ecosystem function. These findings suggest that a broader perspective that incorporates predictable impacts of fishing pressure on ecosystem function is imperative for effective coral reef conservation and management.

ULK1, mammalian target of rapamycin, and mitochondria: linking nutrient availability and autophagy.

PubMed

Kundu, Mondira

2011-05-15

A fundamental function of autophagy conserved from yeast to mammals is mobilization of macromolecules during times of limited nutrient availability, permitting organisms to survive under starvation conditions. In yeast, autophagy is initiated following nitrogen or carbon deprivation, and autophagy mutants die rapidly under these conditions. Similarly, in mammals, autophagy is upregulated in most organs following initiation of starvation, and is critical for survival in the perinatal period following abrupt termination of the placental nutrient supply. The nutrient-sensing kinase, mammalian target of rapamycin, coordinates cellular proliferation and growth with nutrient availability, at least in part by regulating protein synthesis and autophagy-mediated degradation. This review focusses on the regulation of autophagy by Tor, a mammalian target of rapamycin, and Ulk1, a mammalian homolog of Atg1, in response to changes in nutrient availability. Given the importance of mitochondria in maintaining bioenergetic homestasis, and potentially as a source of membrane for autophagosomes during starvation, possible roles for mitochondria in this process are also discussed.

The Potential Importance of Conservation, Restoration and Altered Management Practices for Water Quality in the Wabash River Watershed

NASA Astrophysics Data System (ADS)

Yang, G.; Best, E. P.; Goodwin, S.

2013-12-01

Non-point source (NPS) pollution is one of the leading causes of water quality impairment within the United States. Conservation, restoration and altered management (CRAM) practices may effectively reduce NPS pollutants to receiving water bodies and enhance local and regional ecosystem services. Barriers for the implementation of CRAM include uncertainties related to the extent to which nutrients are removed by CRAM at various spatial and temporal scales, longevity, optimal placement of CRAM within the landscape, and implementation / operation / maintenance costs. We conducted a study aimed at the identification of optimal placement of CRAM in watersheds that reduces N loading to an environmentally sustainable level, at an acceptable, known, cost. For this study, we used a recently developed screening-level modeling approach, WQM-TMDL-N, running in the ArcGIS environment, to estimate nitrogen loading under current land use conditions (NLCD 2006). This model was equipped with a new option to explore the performances of placement of various CRAM types and areas to reduce nitrogen loading to a State-accepted Total Maximum Daily Load (TMDL) standard, with related annual average TN concentration, and a multi-objective algorithm optimizing load and cost. CRAM practices explored for implementation in rural area included buffer strips, nutrient management practices, and wetland restoration. We initially applied this modeling approach to the Tippecanoe River (TR) watershed (8-digit HUC), a headwater of the Wabash River (WR) watershed, where CRAM implementation in rural and urban areas is being planned and implemented at various spatial scales. Consequences of future land use are explored using a 2050 land use/land cover map forecasted by the Land Transformation Model. The WR watershed, IN, drains two-thirds of the state's 92 counties and supports predominantly agricultural land use. Because the WR accounts for over 40% of the nutrient loads of the Ohio River and significantly contributes to the anoxic zone in the Gulf of Mexico (GOM), reduction in TN loading of the WR are expected to directly benefit downstream ecosystem services, including fisheries in the GOM. This modeling approach can be used in support of sustainable integrated watershed management planning.

How to avoid eutrophication in coastal seas? A new approach to derive river-specific combined nitrate and phosphate maximum concentrations.

PubMed

Ménesguen, Alain; Desmit, Xavier; Dulière, Valérie; Lacroix, Geneviève; Thouvenin, Bénédicte; Thieu, Vincent; Dussauze, Morgan

2018-07-01

Since 1950, increase in nitrogen (N) and phosphorus (P) river loadings in the North-East Atlantic (NEA) continental seas has induced a deep change in the marine coastal ecosystems, leading to eutrophication symptoms in some areas. In order to recover a Good Ecological Status (GES) in the NEA, as required by European Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD), reductions in N- and P-river loadings are necessary but they need to be minimal due to their economic impact on the farming industry. In the frame of the "EMoSEM" European project, we used two marine 3D ecological models (ECO-MARS3D, MIRO&CO) covering the Bay of Biscay, the English Channel and the southern North Sea to estimate the contributions of various sources (riverine, oceanic and atmospheric) to the winter nitrate and phosphate marine concentrations. The various distributed descriptors provided by the simulations allowed also to find a log-linear relationship between the 90th percentile of satellite-derived chlorophyll concentrations and the "fully bioavailable" nutrients, i.e. simulated nutrient concentrations weighted by light and stoichiometric limitation factors. Any GES threshold on the 90th percentile of marine chlorophyll concentration can then be translated in maximum admissible 'fully bioavailable' DIN and DIP concentrations, from which an iterative linear optimization method can compute river-specific minimal abatements of N and P loadings. The method has been applied to four major river groups, assuming either a conservative (8μgChlL -1 ) or a more socially acceptable (15μgChlL -1 ) GES chlorophyll concentration threshold. In the conservative case, maximum admissible winter concentrations for nutrients correspond to marine background values, whereas in the lenient case, they are close to values recommended by the WFD/MSFD. Both models suggest that to reach chlorophyll GES, strong reductions of DIN and DIP are required in the Eastern French and Belgian-Dutch river groups. Copyright © 2018 Elsevier B.V. All rights reserved.

Nutrient Intakes: Individuals in 48 States, Year 1977-78. Nationwide Food Consumption Survey 1977-78. Report No. I-2.

ERIC Educational Resources Information Center

Department of Agriculture, Washington, DC.

This report presents 3-day nutrient intake data for about 36,100 individuals in 48 states. Data are provided in 157 tables, and results are summarized in the text. The contribution of 14 food groups to intakes of food energy and 14 nutrients are presented. Also included are the average intakes of food energy and nutrients, the nutrient densities…

Focusing ecological research for conservation.

PubMed

Cristescu, Bogdan; Boyce, Mark S

2013-11-01

Ecologists are increasingly actively involved in conservation. We identify five key topics from a broad sweep of ecology that merit research attention to meet conservation needs. We examine questions from landscape ecology, behavioral ecology, ecosystem dynamics, community ecology, and nutrient cycling related to key topics. Based on literature review and publication trend assessment, consultation with colleagues, and roundtable discussions at the 24th International Congress for Conservation Biology, focused research on the following topics could benefit conservation while advancing ecological understanding: 1. Carbon sequestration, requiring increased linkages to biodiversity conservation; 2. Ecological invasiveness, challenging our ability to find solutions to ecological aliens; 3. Individual variation, having applications in the conservation of rare species; 4. Movement of organisms, integrating ecological processes across landscapes and scales and addressing habitat fragmentation; and 5. Trophic-level interactions, driving ecological dynamics at the ecosystem-level. Addressing these will require cross-disciplinary research under the overarching framework of conservation ecology.

Nutrient sensing modulates malaria parasite virulence.

PubMed

Mancio-Silva, Liliana; Slavic, Ksenija; Grilo Ruivo, Margarida T; Grosso, Ana Rita; Modrzynska, Katarzyna K; Vera, Iset Medina; Sales-Dias, Joana; Gomes, Ana Rita; MacPherson, Cameron Ross; Crozet, Pierre; Adamo, Mattia; Baena-Gonzalez, Elena; Tewari, Rita; Llinás, Manuel; Billker, Oliver; Mota, Maria M

2017-07-13

The lifestyle of intracellular pathogens, such as malaria parasites, is intimately connected to that of their host, primarily for nutrient supply. Nutrients act not only as primary sources of energy but also as regulators of gene expression, metabolism and growth, through various signalling networks that enable cells to sense and adapt to varying environmental conditions. Canonical nutrient-sensing pathways are presumed to be absent from the causative agent of malaria, Plasmodium, thus raising the question of whether these parasites can sense and cope with fluctuations in host nutrient levels. Here we show that Plasmodium blood-stage parasites actively respond to host dietary calorie alterations through rearrangement of their transcriptome accompanied by substantial adjustment of their multiplication rate. A kinome analysis combined with chemical and genetic approaches identified KIN as a critical regulator that mediates sensing of nutrients and controls a transcriptional response to the host nutritional status. KIN shares homology with SNF1/AMPKα, and yeast complementation studies suggest that it is part of a functionally conserved cellular energy-sensing pathway. Overall, these findings reveal a key parasite nutrient-sensing mechanism that is critical for modulating parasite replication and virulence.

The Effects of Nutrient Enrichment and Herbivore Abundance on the Ability of Turf Algae to Overgrow Coral in the Caribbean

PubMed Central

Vermeij, Mark J. A.; van Moorselaar, Imke; Engelhard, Sarah; Hörnlein, Christine; Vonk, Sophie M.; Visser, Petra M.

2010-01-01

Turf algae are multispecies communities of small marine macrophytes that are becoming a dominant component of coral reef communities around the world. To assess the impact of turf algae on corals, we investigated the effects of increased nutrients (eutrophication) on the interaction between the Caribbean coral Montastraea annularis and turf algae at their growth boundary. We also assessed whether herbivores are capable of reducing the abundance of turf algae at coral-algae boundaries. We found that turf algae cause visible (overgrowth) and invisible negative effects (reduced fitness) on neighbouring corals. Corals can overgrow neighbouring turf algae very slowly (at a rate of 0.12 mm 3 wk−1) at ambient nutrient concentrations, but turf algae overgrew corals (at a rate of 0.34 mm 3 wk−1) when nutrients were experimentally increased. Exclusion of herbivores had no measurable effect on the rate turf algae overgrew corals. We also used PAM fluorometry (a common approach for measuring of a colony's “fitness”) to detect the effects of turf algae on the photophysiology of neighboring corals. Turf algae always reduced the effective photochemical efficiency of neighbouring corals, regardless of nutrient and/or herbivore conditions. The findings that herbivores are not capable of controlling the abundance of turf algae and that nutrient enrichment gives turf algae an overall competitive advantage over corals together have serious implications for the health of Caribbean coral reef systems. At ambient nutrient levels, traditional conservation measures aimed at reversing coral-to-algae phase shifts by reducing algal abundance (i.e., increasing herbivore populations by establishing Marine Protected Areas or tightening fishing regulations) will not necessarily reduce the negative impact of turf algae on local coral communities. Because turf algae have become the most abundant benthic group on Curaçao (and likely elsewhere in the Caribbean), new conservation strategies are required to mitigate their negative impact on coral communities. PMID:21179215

Estimation of nutrient discharge from the Yangtze River to the East China Sea and the identification of nutrient sources.

PubMed

Tong, Yindong; Bu, Xiaoge; Chen, Junyue; Zhou, Feng; Chen, Long; Liu, Maodian; Tan, Xin; Yu, Tao; Zhang, Wei; Mi, Zhaorong; Ma, Lekuan; Wang, Xuejun; Ni, Jing

2017-01-05

Based on a time-series dataset and the mass balance method, the contributions of various sources to the nutrient discharges from the Yangtze River to the East China Sea are identified. The results indicate that the nutrient concentrations vary considerably among different sections of the Yangtze River. Non-point sources are an important source of nutrients to the Yangtze River, contributing about 36% and 63% of the nitrogen and phosphorus discharged into the East China Sea, respectively. Nutrient inputs from non-point sources vary among the sections of the Yangtze River, and the contributions of non-point sources increase from upstream to downstream. Considering the rice growing patterns in the Yangtze River Basin, the synchrony of rice tillering and the wet seasons might be an important cause of the high nutrient discharge from the non-point sources. Based on our calculations, a reduction of 0.99Tg per year in total nitrogen discharges from the Yangtze River would be needed to limit the occurrences of harmful algal blooms in the East China Sea to 15 times per year. The extensive construction of sewage treatment plants in urban areas may have only a limited effect on reducing the occurrences of harmful algal blooms in the future. Copyright © 2016 Elsevier B.V. All rights reserved.

Available nutrients in biochar

USDA-ARS?s Scientific Manuscript database

Biochar technology may contribute to the recovery and recycling of plant nutrients and thus add a fertilizer value to the biochar. Total nutrient content in biochars varies greatly and is mainly dependent on feedstock elemental composition and to a lesser extent on pyrolysis conditions. Availability...

Considerations in developing lipid-based nutrient supplements for prevention of undernutrition: experience from the International Lipid-Based Nutrient Supplements (iLANS) Project.

USDA-ARS?s Scientific Manuscript database

The International Lipid-Based Nutrient Supplements (iLiNS) Project began in 2009 with the goal of contributing to the evidence base regarding the potential of lipid-based nutrient supplements (LNS) to prevent undernutrition in vulnerable populations. The first project objective was the development o...

Considerations in developing lipid-based nutrient supplements for prevention of undernutrition: experience from the International Lipid-Based Nutrient Supplements (iLiNS)

USDA-ARS?s Scientific Manuscript database

The International Lipid-Based Nutrient Supplements (iLiNS) Project began in 2009 with the goal of contributing to the evidence base regarding the potential of lipid-based nutrient supplements (LNS) to prevent undernutrition in vulnerable populations. The first project objective was the development o...

Bioregenerative life support systems for microgravity

NASA Technical Reports Server (NTRS)

Nevill, Gail E., Jr.; Hessel, Michael I., Jr.; Rodriguez, Jose; Morgan, Steve (Editor)

1993-01-01

NASA's Controlled Ecological Life Support System (CELSS) project centers on growing plants and recycling wastes in space. The current version of the biomass production chamber (BPC) uses a hydroponic system for nutrient delivery. To optimize plant growth and conserve system resources, the content of the nutrient solution which feeds the plants must be constantly monitored. The macro-nutrients (greater than ten ppm) in the solution include nitrogen, phosphorous, potassium, calcium, magnesium, and sulphur; the micro-nutrients (less than ten ppm) include iron, copper, manganese, zinc, and boron. The goal of this project is to construct a computer-controlled system of ion detectors that will accurately measure the concentrations of several necessary ions in solution. The project focuses on the use of a sensor array to eliminate problems of interference and temperature dependence.

A conserved α-proteobacterial small RNA contributes to osmoadaptation and symbiotic efficiency of rhizobia on legume roots.

PubMed

Robledo, Marta; Peregrina, Alexandra; Millán, Vicenta; García-Tomsig, Natalia I; Torres-Quesada, Omar; Mateos, Pedro F; Becker, Anke; Jiménez-Zurdo, José I

2017-07-01

Small non-coding RNAs (sRNAs) are expected to have pivotal roles in the adaptive responses underlying symbiosis of nitrogen-fixing rhizobia with legumes. Here, we provide primary insights into the function and activity mechanism of the Sinorhizobium meliloti trans-sRNA NfeR1 (Nodule Formation Efficiency RNA). Northern blot probing and transcription tracking with fluorescent promoter-reporter fusions unveiled high nfeR1 expression in response to salt stress and throughout the symbiotic interaction. The strength and differential regulation of nfeR1 transcription are conferred by a motif, which is conserved in nfeR1 promoter regions in α-proteobacteria. NfeR1 loss-of-function compromised osmoadaptation of free-living bacteria, whilst causing misregulation of salt-responsive genes related to stress adaptation, osmolytes catabolism and membrane trafficking. Nodulation tests revealed that lack of NfeR1 affected competitiveness, infectivity, nodule development and symbiotic efficiency of S. meliloti on alfalfa roots. Comparative computer predictions and a genetic reporter assay evidenced a redundant role of three identical NfeR1 unpaired anti Shine-Dalgarno motifs for targeting and downregulation of translation of multiple mRNAs from transporter genes. Our data provide genetic evidence of the hyperosmotic conditions of the endosymbiotic compartments. NfeR1-mediated gene regulation in response to this cue could contribute to coordinate nutrient uptake with the metabolic reprogramming concomitant to symbiotic transitions. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

The Impact of Nature Experience on Willingness to Support Conservation

PubMed Central

Zaradic, Patricia A.; Pergams, Oliver R. W.; Kareiva, Peter

2009-01-01

We hypothesized that willingness to financially support conservation depends on one's experience with nature. In order to test this hypothesis, we used a novel time-lagged correlation analysis to look at times series data concerning nature participation, and evaluate its relationship with future conservation support (measured as contributions to conservation NGOs). Our results suggest that the type and timing of nature experience may determine future conservation investment. Time spent hiking or backpacking is correlated with increased conservation contributions 11–12 years later. On the other hand, contributions are negatively correlated with past time spent on activities such as public lands visitation or fishing. Our results suggest that each hiker or backpacker translates to $200–$300 annually in future NGO contributions. We project that the recent decline in popularity of hiking and backpacking will negatively impact conservation NGO contributions from approximately 2010–2011 through at least 2018. PMID:19809511

Childhood obesity and the consumption of 100% fruit juice: Where are the evidence-based findings?

USDA-ARS?s Scientific Manuscript database

With every food or beverage that contributes to total energy intake, it is important to weigh the contribution of the food or beverage to diet and health. Consumers of 100% fruit juice (FJ) showed better nutrient intake, nutrient adequacy, and diet quality than nonconsumers, suggesting that 100% FJ ...

DYNAMICS OF NUTRIENTS AND HYDROLOGY IN A LAKE SUPERIOR COASTAL WETLAND

EPA Science Inventory

Coastal wetlands are hydrologically complex ecosystems situated at the interface of upland catchments and oligotrophic Lake Superior. Little is known about nutrient dynamics within coastal wetlands or their role in modifying or contributing to nutrient fluxes from watersheds to ...

Energy and nutrient flows connecting coastal wetland food webs to land and lake

EPA Science Inventory

Both landscape character and hydrologic forces (principally, tributary discharge and seiches) can influence utilization of externally-derived energy and nutrients in coastal wetland food webs. We quantified the contribution of internal vs external energy and nutrients among wetla...

Nutrient transport within and between habitats through seed dispersal processes by woolly monkeys in north-western Amazonia.

PubMed

Stevenson, Pablo R; Guzmán-Caro, Diana C

2010-11-01

The contribution of vertebrate animals to nutrient cycling has proven to be important in various ecosystems. However, the role of large bodied primates in nutrient transport in neotropical forests is not well documented. Here, we assess the role of a population of woolly monkeys (Lagothrix lagothricha lugens) as vectors of nutrient movement through seed dispersal. We estimated total seed biomass transported by the population within and between two habitats (terra firme and flooded forests) at Tinigua Park, Colombia, and quantified potassium (K), phosphorus (P) and nitrogen (N) content in seeds of 20 plant species from both forests. Overall, the population transported an estimated minimum of 11.5 (±1.2 SD) g of potassium, 13.2 (±0.7) g of phosphorus and 34.3 (±0.1) g nitrogen, within 22.4 (±2.0) kg of seeds ha(-1) y(-1). Approximately 84% of all nutrients were deposited in the terra firme forest mostly through recycling processes, and also through translocation from the flooded forest. This type of translocation represents an important and high-quality route of transport since abiotic mechanisms do not usually move nutrients upwards, and since chemical tests show that seeds from flooded forests have comparatively higher nutrient contents. The overall contribution to nutrient movement by the population of woolly monkeys is significant because of the large amount of biomass transported, and the high phosphorus content of seeds. As a result, the phosphorus input generated by these monkeys is of the same order of magnitude as other abiotic mechanisms of nutrient transport such as atmospheric deposition and some weathering processes. Our results suggest that via seed dispersal processes, woolly monkey populations can contribute to nutrient movement in tropical forests, and may act as important nutrient input vectors in terra firme forests. © 2010 Wiley-Liss, Inc.

Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

NASA Astrophysics Data System (ADS)

Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

2018-03-01

As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

Nutrient conservation during spent mushroom compost application using spent mushroom substrate derived biochar.

PubMed

Lou, Zimo; Sun, Yue; Bian, Shuping; Ali Baig, Shams; Hu, Baolan; Xu, Xinhua

2017-02-01

Spent mushroom compost (SMC), a spent mushroom substrate (SMS) derived compost, is always applied to agriculture land to enhance soil organic matter and nutrient contents. However, nitrogen, phosphate and organic matter contained in SMC can leach out and contaminate ground water during its application. In this study, biochars prepared under different pyrolytic temperatures (550 °C, 650 °C or 750 °C) from SMS were applied to soil as a nutrient conservation strategy. The resultant biochars were characterized for physical and mineralogical properties. Surface area and pore volume of biochars increased as temperature increased, while pore size decreased with increasing temperature. Calcite and quartz were evidenced by X-ray diffraction analysis in all biochars produced. Results of column leaching test suggested that mixed treatment of SMC and SMS-750-800 (prepared with the temperature for pyrolysis and activation was chosen as 750 °C and 800 °C, respectively) could reduce 43% of TN and 66% of COD Cr in leachate as compared to chemical fertilizers and SMC, respectively. Furthermore, increasing dosage of SMS-750-800 from 1% to 5% would lead to 54% COD Cr reduction in leachate, which confirmed its nutrient retention capability. Findings from this study suggested that combined application of SMC and SMS-based biochar was an applicable strategy for reducing TN and COD Cr leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

Farmer Heroes Manage Nutrients On Farm

EPA Pesticide Factsheets

These featured farmers have been identified by the National Association of Conservation Districts and EPA for implementing specific best management practices to reduce pollution while also improving or sustaining their profits, soil quality or yields.

Sediment and solute transport in a mountainous watershed in Valle del Cauca, Colombia

NASA Astrophysics Data System (ADS)

Guzman, Christian; Hoyos Villada, Fanny; Morales Vargas, Amalia; Rivera, Baudelino; Da Silva, Mayesse; Moreno Padilla, Pedro; Steenhuis, Tammo

2015-04-01

Sediment samples and solute concentrations were measured from the La Vega micro watershed in the southwestern region of the Colombian Andes. A main goal of this study was to improve prediction of soil surface and soil nutrient changes, based on field measurements, within small basin of the Aguaclara watershed network receiving different types of conservation measures. Two modeling approaches for stream discharge and sediment transport predictions were used with one of these based on infiltration-excess and the other on saturation-excess runoff. These streams are a part of a recent initiative from a water fund established by Asobolo, Asocaña, and Cenicaña in collaboration with the Natural Capital Project to improve conservation efforts and monitor their effects. On-site soil depth changes, groundwater depth measurements, and soil nutrient concentrations were also monitored to provide more information about changes within this mountainous watershed during one part of the yearly rainy season. This information is being coupled closely with the outlet sediment concentration and solute concentration patterns to discern correlations between scales. Lateral transects in the upper, middle, and lower part of the hillsides in the La Vega micro watershed showed differences in soil nutrient status and soil surface depth changes. The model based on saturation-excess, semi-distributed hydrology was able to reproduce discharge and sediment transport rates as well as the initially used infiltration excess model indicating available options for comparison of conservation changes in the future.

Investigating the Environmental Effects of Agriculture Practices on Natural Resources: Scientific Contributions of the U.S. Geological Survey to Enhance the Management of Agricultural Landscapes

USGS Publications Warehouse

,

2007-01-01

The U.S. Geological Survey (USGS) enhances and protects the quality of life in the United States by advancing scientific knowledge to facilitate effective management of hydrologic, biologic, and geologic resources. Results of selected USGS research and monitoring projects in agricultural landscapes are presented in this Fact Sheet. Significant environmental and social issues associated with agricultural production include changes in the hydrologic cycle; introduction of toxic chemicals, nutrients, and pathogens; reduction and alteration of wildlife habitats; and invasive species. Understanding environmental consequences of agricultural production is critical to minimize unintended environmental consequences. The preservation and enhancement of our natural resources can be achieved by measuring the success of improved management practices and by adjusting conservation policies as needed to ensure long-term protection.

Mammalian autophagy and the plasma membrane.

PubMed

Pavel, Mariana; Rubinsztein, David C

2017-03-01

Autophagy (literally 'self-eating') is an evolutionarily conserved degradation process where cytoplasmic components are engulfed by vesicles called autophagosomes, which are then delivered to lysosomes, where their contents are degraded. Under stress conditions, such as starvation or oxidative stress, autophagy is upregulated in order to degrade macromolecules and restore the nutrient balance. The source of membranes that participate in the initial formation of phagophores is still incompletely understood and many intracellular structures have been shown to act as lipid donors, including the endoplasmic reticulum, Golgi, nucleus, mitochondria and the plasma membrane. Here, we focus on the contributions of the plasma membrane to autophagosome biogenesis governed by ATG16L1 and ATG9A trafficking, and summarize the physiological and pathological implications of this macroautophagy route, from development and stem cell fate to neurodegeneration and cancer. © 2016 Federation of European Biochemical Societies.

Development of complementary feeding recommendations for 12-23-month-old children from low and middle socio-economic status in West Java, Indonesia: contribution of fortified foods towards meeting the nutrient requirement.

PubMed

Fahmida, Umi; Santika, Otte

2016-07-01

Inadequate nutrient intake as part of a complementary feeding diet is attributable to poor feeding practices and poor access to nutritious foods. Household socio-economic situation (SES) has an influence on food expenditure and access to locally available, nutrient-dense foods and fortified foods. This study aimed to develop and compare complementary feeding recommendations (CFR) for 12-23-month-old children in different SES and evaluate the contribution of fortified foods in meeting nutrient requirements. A cross-sectional survey was conducted in low and medium SES households (n 114/group) in urban Bandung district, West Java province, Indonesia. Food pattern, portion size and affordability were assessed, and CFR were developed for the low SES (LSES) and middle SES (MSES) using a linear programming (LP) approach; two models - with and without fortified foods - were run using LP, and the contribution of fortified foods in the final CFR was identified. Milk products, fortified biscuits and manufactured infant cereals were the most locally available and consumed fortified foods in the market. With the inclusion of fortified foods, problem nutrients were thiamin in LSES and folate and thiamin in MSES groups. Without fortified foods, more problem nutrients were identified in LSES, that is, Ca, Fe, Zn, niacin and thiamin. As MSES consumed more fortified foods, removing fortified foods was not possible, because most of the micronutrient-dense foods were removed from their food basket. There were comparable nutrient adequacy and problem nutrients between LSES and MSES when fortified foods were included. Exclusion of fortified foods in LSES was associated with more problem nutrients in the complementary feeding diet.

The relative role of captive breeding and of zoo-bred animals in North American conservation translocations.

PubMed

Brichieri-Colombi, Typhenn A; Lloyd, Natasha A; Mcpherson, Jana M; Moehrenschlager, Axel

2018-06-19

With the loss of biodiversity accelerating, conservation translocations such as reintroductions are becoming an increasingly common conservation tool. Conservation translocations must source individuals for release from either wild or captive-bred populations. We asked what proportion of North American conservation translocations rely on captive breeding, and to what extent zoos and aquaria (hereafter zoos) fulfill captive breeding needs. Our comprehensive literature review indicates that North American conservation translocations published before 2014 involved captive breeding for 162 (58%) of the 279 animal species translocated. Fifty-four zoos contributed animals for release; the fourty species of animals bred for release by zoos represents only 14% of all animal species for which conservation translocations were published, and only 25% of all animal species that were bred for releases occurring in North America. Zoo contributions varied by taxon, ranging from zoo-bred animals released in 42% of amphibian conservation translocations to zero contributions for marine invertebrates. Proportional involvement of zoos in captive breeding programs for release has increased over time as has the proportion of translocation-focused scientific papers co-authored by zoo professionals. While zoos also contribute to conservation translocations through education, funding, and professional expertise, increasing the contribution of animals for release in responsible conservation translocation programs presents a future conservation need and opportunity. We especially encourage increased dialogue and planning between the zoo community, academic institutions, and governments to optimize the direct contribution zoos can make to wildlife conservation through conservation translocations. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The Nutritional Geometry of Resource Scarcity: Effects of Lean Seasons and Habitat Disturbance on Nutrient Intakes and Balancing in Wild Sifakas

PubMed Central

Irwin, Mitchell T.; Raharison, Jean-Luc; Raubenheimer, David R.; Chapman, Colin A.; Rothman, Jessica M.

2015-01-01

Animals experience spatial and temporal variation in food and nutrient supply, which may cause deviations from optimal nutrient intakes in both absolute amounts (meeting nutrient requirements) and proportions (nutrient balancing). Recent research has used the geometric framework for nutrition to obtain an improved understanding of how animals respond to these nutritional constraints, among them free-ranging primates including spider monkeys and gorillas. We used this framework to examine macronutrient intakes and nutrient balancing in sifakas (Propithecus diadema) at Tsinjoarivo, Madagascar, in order to quantify how these vary across seasons and across habitats with varying degrees of anthropogenic disturbance. Groups in intact habitat experience lean season decreases in frugivory, amounts of food ingested, and nutrient intakes, yet preserve remarkably constant proportions of dietary macronutrients, with the proportional contribution of protein to the diet being highly consistent. Sifakas in disturbed habitat resemble intact forest groups in the relative contribution of dietary macronutrients, but experience less seasonality: all groups’ diets converge in the lean season, but disturbed forest groups largely fail to experience abundant season improvements in food intake or nutritional outcomes. These results suggest that: (1) lemurs experience seasonality by maintaining nutrient balance at the expense of calories ingested, which contrasts with earlier studies of spider monkeys and gorillas, (2) abundant season foods should be the target of habitat management, even though mortality might be concentrated in the lean season, and (3) primates’ within-group competitive landscapes, which contribute to variation in social organization, may vary in complex ways across habitats and seasons. PMID:26061401

Feasibility of Estimating Relative Nutrient Contributions of Agriculture and Forests Using MODIS Time Series

NASA Technical Reports Server (NTRS)

Ross, Kenton W.; Gasser, Gerald; Spiering, Bruce

2010-01-01

Around the Gulf of Mexico, high-input crops in several regions make a significant contribution to nutrient loading of small to medium estuaries and to the near-shore Gulf. Some crops cultivated near the coast include sorghum in Texas, rice in Texas and Louisiana, sugarcane in Florida and Louisiana, citrus orchards in Florida, pecan orchards in Mississippi and Alabama, and heavy sod and ornamental production around Mobile and Tampa Bay. In addition to crops, management of timberlands in proximity to the coasts also plays a role in nutrient loading. In the summer of 2008, a feasibility project is planned to explore the use of NASA data to enhance the spatial and temporal resolution of near-coast nutrient source information available to the coastal community. The purpose of this project is to demonstrate the viability of nutrient source information products applicable to small to medium watersheds surrounding the Gulf of Mexico. Conceptually, these products are intended to complement estuarine nutrient monitoring.

The Estuaries Contribution for Supplying Nutrients (N and P) in Jepara Using Numerical Modelling Approach

NASA Astrophysics Data System (ADS)

Maslukah, Lilik; Yulina Wulandari, Sri; Budi Prasetyawan, Indra

2018-02-01

Coastal water is dynamic area since it is influenced by both ocean and land. It has high primary productivity that determined fishing ground area. Increased supply of nutrients in coastal water is significantly influenced by seasons and the presence of the river estuaries carrying water masses from the mainland. This study focused on the rivers (Serang, Wiso, Grenjengan Mlonggo and Pasokan rivers) contributed nutrients supply spatially and temporally to Jepara water using numerical modeling. The results showed nutrients content of N (Nitrate) and P (Phosphate) from those rivers were 39.19 tons N/month and 2.26 tons P/month in June, 19.94 tons N/month and 1.96 tons P/month in August. From simulation modeling nutrient of N and P showed that the distribution pattern of N and P was larger during the neap tide than the spring tide. Furthermore, compared with the other rivers, Serang river was the highest nutrient supplier to Jepara water.

Feasibility of Estimating Relative Nutrient Contributions of Agriculture using MODIS Time Series

NASA Technical Reports Server (NTRS)

Ross, Kenton W.; Gasser, Gerald; Spiering, Bruce

2008-01-01

Around the Gulf of Mexico, high-input crops in several regions make a significant contribution to nutrient loading of small to medium estuaries and to the near-shore Gulf. Some crops cultivated near the coast include sorghum in Texas, rice in Texas and Louisiana, sugarcane in Florida and Louisiana, citrus orchards in Florida, pecan orchards in Mississippi and Alabama, and heavy sod and ornamental production around Mobile and Tampa Bay. In addition to crops, management of timberlands in proximity to the coasts also plays a role in nutrient loading. In the summer of 2008, a feasibility project is planned to explore the use of NASA data to enhance the spatial and temporal resolution of near-coast nutrient source information available to the coastal community. The purpose of this project is to demonstrate the viability of nutrient source information products applicable to small to medium watersheds surrounding the Gulf of Mexico. Conceptually, these products are intended to complement estuarine nutrient monitoring.

In vivo gene expression and the adaptive response: from pathogenesis to vaccines and antimicrobials.

PubMed Central

Heithoff, D M; Sinsheimer, R L; Low, D A; Mahan, M J

2000-01-01

Microbial pathogens possess a repertoire of virulence determinants that each make unique contributions to fitness during infection. Analysis of these in vivo-expressed functions reveals the biology of the infection process, encompassing the bacterial infection strategies and the host ecological and environmental retaliatory strategies designed to combat them (e.g. thermal, osmotic, oxygen, nutrient and acid stress). Many of the bacterial virulence functions that contribute to a successful infection are normally only expressed during infection. A genetic approach was used to isolate mutants that ectopically expressed many of these functions in a laboratory setting. Lack of DNA adenine methylase (Dam) in Salmonella typhimurium abolishes the preferential expression of many bacterial virulence genes in host tissues. Dam- Salmonella were proficient in colonization of mucosal sites but were defective in colonization of deeper tissue sites. Additionally, Dam- mutants were totally avirulent and effective as live vaccines against murine typhoid fever. Since dam is highly conserved in many pathogenic bacteria that cause significant morbidity and mortality worldwide, Dams are potentially excellent targets for both vaccines and antimicrobials. PMID:10874736

Serine- and Threonine/Valine-Dependent Activation of PDK and Tor Orthologs Converge on Sch9 to Promote Aging

PubMed Central

Fabrizio, Paola; Wei, Min; Hu, Jia; Longo, Valter D.

2014-01-01

Dietary restriction extends longevity in organisms ranging from bacteria to mice and protects primates from a variety of diseases, but the contribution of each dietary component to aging is poorly understood. Here we demonstrate that glucose and specific amino acids promote stress sensitization and aging through the differential activation of the Ras/cAMP/PKA, PKH1/2 and Tor/S6K pathways. Whereas glucose sensitized cells through a Ras-dependent mechanism, threonine and valine promoted cellular sensitization and aging primarily by activating the Tor/S6K pathway and serine promoted sensitization via PDK1 orthologs Pkh1/2. Serine, threonine and valine activated a signaling network in which Sch9 integrates TORC1 and Pkh signaling via phosphorylation of threonines 570 and 737 and promoted intracellular relocalization and transcriptional inhibition of the stress resistance protein kinase Rim15. Because of the conserved pro-aging role of nutrient and growth signaling pathways in higher eukaryotes, these results raise the possibility that similar mechanisms contribute to aging in mammals. PMID:24516402

Yeast chronological lifespan and proteotoxic stress: is autophagy good or bad?

PubMed

Sampaio-Marques, Belém; Felgueiras, Carolina; Silva, Alexandra; Rodrigues, Fernando; Ludovico, Paula

2011-10-01

Autophagy, a highly conserved proteolytic mechanism of quality control, is essential for the maintenance of metabolic and cellular homoeostasis and for an efficient cellular response to stress. Autophagy declines with aging and is believed to contribute to different aspects of the aging phenotype. The nutrient-sensing pathways PKA (protein kinase A), Sch9 and TOR (target of rapamycin), involved in the regulation of yeast lifespan, also converge on a common targeted process: autophagy. The molecular mechanisms underlying the regulation of autophagy and aging by these signalling pathways in yeast, with special attention to the TOR pathway, are discussed in the present paper. The question of whether or not autophagy could contribute to yeast cell death occurring during CLS (chronological lifespan) is discussed in the light of our findings obtained after autophagy activation promoted by proteotoxic stress. Autophagy progressively increases in cells expressing the aggregation-prone protein α-synuclein and seems to participate in the early cell death and shortening of CLS under these conditions, highlighting that autophagic activity should be maintained below physiological levels to exert its promising anti-aging effects.

Food and nutrient intakes of French frequent seafood consumers with regard to fish consumption recommendations: results from the CALIPSO study.

PubMed

Sirot, Véronique; Dumas, Céline; Leblanc, Jean-Charles; Margaritis, Irène

2011-05-01

Besides providing n-3 fatty acids with nutritional and health benefits, seafood consumption may contribute to the reduction of nutrient prevalences of inadequacy. To evaluate the contributions of seafood and other food groups to nutrient intakes of frequent seafood consumers, food consumption was evaluated through an FFQ on 991 French men and women (18-81 years) consuming seafood at least twice a week. Intakes, prevalence of inadequacies, risks of upper limit excess and food contributions to intakes were assessed for thirty-three nutrients. Mean fat contributions to total energy intakes (38·3 and 39·0 % for men and women, respectively) met French recommendations, but mean carbohydrate intakes (40·9 and 39·7 %, respectively) were insufficient. Micronutrient inadequacies were lower than in the French general population, the highest being for vitamin C (41·3 and 40·1 % for men and women, respectively), vitamin E (35·0 and 35·3 % for men and women, respectively) and Mg (37·5 and 25·5 % for men and women, respectively). Upper safety limits (USL) were exceeded mostly for Zn (6·2 %), Ca (3·7 %), retinol (2·0 %) and Cu (0·9 %). Mean contributions of seafood to vitamin D, B12, I and Se intakes ranged 40-65 %. Molluscs and crustaceans significantly contributed to vitamin B12 (13·7 %), Cu (11·4 %), Fe (11·5 %), Zn (8·4 %) and I (6·1 %) intakes, and canned fish contributed to vitamin D intake (13·4 %). Besides fish, contributions of mollusc and crustacean consumption to nutrient intakes should be considered from a public health viewpoint. Consuming seafood at least twice a week induces moderate inadequacies and risks of exceeding USL for some micronutrients, whereas macronutrient intakes remained imbalanced.

Measuring nutrient flux in Pacific Coast salt marshes using fluctuating water-level chambers

EPA Science Inventory

Nutrient removal from the water column is an important ecosystem function that contributes to the production of clean water, a final valued ecosystem service of wetlands. However, little data is currently available for nutrient exchange in Pacific Northwest tidal ecosystems. We h...

Nutritional assessment of charitable meal programmes serving homeless people in Toronto.

PubMed

Tse, Carmen; Tarasuk, Valerie

2008-12-01

To assess the potential nutritional contribution of meals provided in a sample of community programmes for homeless individuals, to determine the effect of food donations on meal quality and to develop food-based guidance for meals that would meet adults' total nutrient needs. Toronto, Canada. An analysis of weighed meal records from eighteen programmes. The energy and nutrient contents of meals were compared to requirement estimates to assess contribution to total needs, given that homeless people have limited access to nutritious foods. Mixed linear modelling was applied to determine the relationship between the use of food donations and meal quality. The composition of meals that would meet adults' nutrient requirements was determined by constructing simulated meals, drawing on the selection of foods available to programmes. In all, seventy meals, sampled from eighteen programmes serving homeless individuals. On average, the meals contained 2.6 servings of grain products, 1.7 servings of meat and alternatives, 4.1 servings of vegetables and fruits and 0.4 servings of milk products. The energy and nutrient contents of most meals were below adults' average daily requirements. Most meals included both purchased and donated foods; the vitamin C content of meals was positively associated with the percentage of energy from donations. Increasing portion sizes improved the nutrient contribution of meals, but the provision of more milk products and fruits and vegetables was required to meet adults' nutrient requirements. The meals assessed were inadequate to meet adults' nutrient requirements. Improving the nutritional quality of meals requires additional resources.

The third National Food Consumption Survey, INRAN-SCAI 2005-06: major dietary sources of nutrients in Italy.

PubMed

Sette, Stefania; Le Donne, Cinzia; Piccinelli, Raffaela; Mistura, Lorenza; Ferrari, Marika; Leclercq, Catherine

2013-12-01

To promote healthy food consumption patterns, information is required on the contribution of food groups to total nutrient intake. The objective of this paper is to identify the main dietary sources of nutrients in the diet of the population in Italy. Data collected through individual food records within the INRAN-SCAI 2005-06 survey were required. The final sample included 3323 subjects aged 0.1-97.7 years. The percentage contributed by each food category to the intake of energy, dietary fibre and of 26 nutrients was calculated. Above 3 years of age, the main contributors to macro- and micro-nutrient intakes were similar among the various age-sex groupings with few exceptions. These data might be used to develop specific strategies for Italy in order to increase the intake of dietary fibre and to decrease that of total fats and of sugars in the population.

Dual role of starvation signaling in promoting growth and recovery

PubMed Central

Leshkowitz, Dena; Barkai, Naama

2017-01-01

Growing cells are subject to cycles of nutrient depletion and repletion. A shortage of nutrients activates a starvation program that promotes growth in limiting conditions. To examine whether nutrient-deprived cells prepare also for their subsequent recovery, we followed the transcription program activated in budding yeast transferred to low-phosphate media and defined its contribution to cell growth during phosphate limitation and upon recovery. An initial transcription wave was induced by moderate phosphate depletion that did not affect cell growth. A second transcription wave followed when phosphate became growth limiting. The starvation program contributed to growth only in the second, growth-limiting phase. Notably, the early response, activated at moderate depletion, promoted recovery from starvation by increasing phosphate influx upon transfer to rich medium. Our results suggest that cells subject to nutrient depletion prepare not only for growth in the limiting conditions but also for their predicted recovery once nutrients are replenished. PMID:29236696

The GATOR1 Complex Regulates Metabolic Homeostasis and the Response to Nutrient Stress in Drosophila melanogaster.

PubMed

Wei, Youheng; Reveal, Brad; Cai, Weili; Lilly, Mary A

2016-12-07

TORC1 regulates metabolism and growth in response to a large array of upstream inputs. The evolutionarily conserved trimeric GATOR1 complex inhibits TORC1 activity in response to amino acid limitation. In humans, the GATOR1 complex has been implicated in a wide array of pathologies including cancer and hereditary forms of epilepsy. However, the precise role of GATOR1 in animal physiology remains largely undefined. Here, we characterize null mutants of the GATOR1 components nprl2, nprl3, and iml1 in Drosophila melanogaster We demonstrate that all three mutants have inappropriately high baseline levels of TORC1 activity and decreased adult viability. Consistent with increased TORC1 activity, GATOR1 mutants exhibit a cell autonomous increase in cell growth. Notably, escaper nprl2 and nprl3 mutant adults have a profound locomotion defect. In line with a nonautonomous role in the regulation of systemic metabolism, expressing the Nprl3 protein in the fat body, a nutrient storage organ, and hemocytes but not muscles and neurons rescues the motility of nprl3 mutants. Finally, we show that nprl2 and nprl3 mutants fail to activate autophagy in response to amino acid limitation and are extremely sensitive to both amino acid and complete starvation. Thus, in Drosophila, in addition to maintaining baseline levels of TORC1 activity, the GATOR1 complex has retained a critical role in the response to nutrient stress. In summary, the TORC1 inhibitor GATOR1 contributes to multiple aspects of the development and physiology of Drosophila. Copyright © 2016 Wei et al.

Processed foods: contributions to nutrition.

PubMed

Weaver, Connie M; Dwyer, Johanna; Fulgoni, Victor L; King, Janet C; Leveille, Gilbert A; MacDonald, Ruth S; Ordovas, Jose; Schnakenberg, David

2014-06-01

Both fresh and processed foods make up vital parts of the food supply. Processed food contributes to both food security (ensuring that sufficient food is available) and nutrition security (ensuring that food quality meets human nutrient needs). This ASN scientific statement focuses on one aspect of processed foods: their nutritional impacts. Specifically, this scientific statement 1) provides an introduction to how processed foods contribute to the health of populations, 2) analyzes the contribution of processed foods to "nutrients to encourage" and "constituents to limit" in the American diet as recommended by the Dietary Guidelines for Americans, 3) identifies the responsibilities of various stakeholders in improving the American diet, and 4) reviews emerging technologies and the research needed for a better understanding of the role of processed foods in a healthy diet. Analyses of the NHANES 2003-2008 show that processed foods provide both nutrients to encourage and constituents to limit as specified in the 2010 Dietary Guidelines for Americans. Of the nutrients to encourage, processed foods contributed 55% of dietary fiber, 48% of calcium, 43% of potassium, 34% of vitamin D, 64% of iron, 65% of folate, and 46% of vitamin B-12. Of the constituents to limit, processed foods contributed 57% of energy, 52% of saturated fat, 75% of added sugars, and 57% of sodium. Diets are more likely to meet food guidance recommendations if nutrient-dense foods, either processed or not, are selected. Nutrition and food science professionals, the food industry, and other stakeholders can help to improve the diets of Americans by providing a nutritious food supply that is safe, enjoyable, affordable, and sustainable by communicating effectively and accurately with each other and by working together to improve the overall knowledge of consumers. © 2014 American Society for Nutrition.

A mathematical model for soil solute transfer into surface runoff as influenced by rainfall detachment.

PubMed

Yang, Ting; Wang, Quanjiu; Wu, Laosheng; Zhao, Guangxu; Liu, Yanli; Zhang, Pengyu

2016-07-01

Nutrients transport is a main source of water pollution. Several models describing transport of soil nutrients such as potassium, phosphate and nitrate in runoff water have been developed. The objectives of this research were to describe the nutrients transport processes by considering the effect of rainfall detachment, and to evaluate the factors that have greatest influence on nutrients transport into runoff. In this study, an existing mass-conservation equation and rainfall detachment process were combined and augmented to predict runoff of nutrients in surface water in a Loess Plateau soil in Northwestern Yangling, China. The mixing depth is a function of time as a result of rainfall impact, not a constant as described in previous models. The new model was tested using two different sub-models of complete-mixing and incomplete-mixing. The complete-mixing model is more popular to use for its simplicity. It captured the runoff trends of those high adsorption nutrients, and of nutrients transport along steep slopes. While the incomplete-mixing model predicted well for the highest observed concentrations of the test nutrients. Parameters inversely estimated by the models were applied to simulate nutrients transport, results suggested that both models can be adopted to describe nutrients transport in runoff under the impact of rainfall. Copyright © 2016 Elsevier B.V. All rights reserved.

Higher photosynthesis, nutrient- and energy-use efficiencies contribute to invasiveness of exotic plants in a nutrient poor habitat in northeast China.

PubMed

Liu, Ming-Chao; Kong, De-Liang; Lu, Xiu-Rong; Huang, Kai; Wang, Shuo; Wang, Wei-Bin; Qu, Bo; Feng, Yu-Long

2017-08-01

The roles of photosynthesis-related traits in invasiveness of introduced plant species are still not well elucidated, especially in nutrient-poor habitats. In addition, little effort has been made to determine the physiological causes and consequences of the difference in these traits between invasive and native plants. To address these problems, we compared the differences in 16 leaf functional traits related to light-saturated photosynthetic rate (P max ) between 22 invasive and native plants in a nutrient-poor habitat in northeast China. The invasive plants had significantly higher P max , photosynthetic nitrogen- (PNUE), phosphorus- (PPUE), potassium- (PKUE) and energy-use efficiencies (PEUE) than the co-occurring natives, while leaf nutrient concentrations, construction cost (CC) and specific leaf area were not significantly different between the invasive and native plants. The higher PNUE contributed to higher P max for the invasive plants, which in turn contributed to higher PPUE, PKUE and PEUE. CC changed independently with other traits such as P max , PNUE, PPUE, PKUE and PEUE, showing two trait dimensions, which may facilitate acclimation to multifarious niche dimensions. Our results indicate that the invasive plants have a superior resource-use strategy, i.e. higher photosynthesis under similar resource investments, contributing to invasion success in the barren habitat. © 2017 Scandinavian Plant Physiology Society.

Review: Feeding conserved forage to horses: recent advances and recommendations.

PubMed

Harris, P A; Ellis, A D; Fradinho, M J; Jansson, A; Julliand, V; Luthersson, N; Santos, A S; Vervuert, I

2017-06-01

The horse is a non-ruminant herbivore adapted to eating plant-fibre or forage-based diets. Some horses are stabled for most or the majority of the day with limited or no access to fresh pasture and are fed preserved forage typically as hay or haylage and sometimes silage. This raises questions with respect to the quality and suitability of these preserved forages (considering production, nutritional content, digestibility as well as hygiene) and required quantities. Especially for performance horses, forage is often replaced with energy dense feedstuffs which can result in a reduction in the proportion of the diet that is forage based. This may adversely affect the health, welfare, behaviour and even performance of the horse. In the past 20 years a large body of research work has contributed to a better and deeper understanding of equine forage needs and the physiological and behavioural consequences if these are not met. Recent nutrient requirement systems have incorporated some, but not all, of this new knowledge into their recommendations. This review paper amalgamates recommendations based on the latest understanding in forage feeding for horses, defining forage types and preservation methods, hygienic quality, feed intake behaviour, typical nutrient composition, digestion and digestibility as well as health and performance implications. Based on this, consensual applied recommendations for feeding preserved forages are provided.

Major food sources of calories, added sugars, and saturated fat and their contribution to essential nutrient intakes in the U.S. diet: data from the National Health and Nutrition Examination Survey (2003-2006).

PubMed

Huth, Peter J; Fulgoni, Victor L; Keast, Debra R; Park, Keigan; Auestad, Nancy

2013-08-08

The risk of chronic disease cannot be predicted simply by the content of a single nutrient in a food or food group in the diet. The contribution of food sources of calories, added sugars and saturated fat (SFA) to intakes of dietary fiber and micronutrients of public health importance is also relevant to understanding the overall dietary impact of these foods. Identify the top food sources of calories, added sugars and SFA in the U.S. diet and quantify their contribution to fiber and micronutrient intakes. Single 24-hour dietary recalls (Day 1) collected from participants ≥2 years (n = 16,822) of the What We Eat in America, National Health and Nutrition Examination Survey (WWEIA/NHANES 2003-2006) were analyzed. All analyses included sample weights to account for the survey design. Calorie and nutrient intakes from foods included contributions from disaggregated food mixtures and tabulated by rank order. No one food category contributes more than 7.2% of calories to the overall U.S. diet, but half of the top 10 contribute 10% or more of total dietary fiber and micronutrients. Three of the top 10 sources of calories and SFA (beef, milk and cheese) contribute 46.3% of the calcium, 49.5% of the vitamin D, 42.3% of the vitamin B12 as well as other essential nutrients to the American diet. On the other hand, foods categorized as desserts, snacks, or beverages, contribute 13.6% of total calories, 83% of added sugar intake, and provide little or no nutritional value. Including food components of disaggregated recipes more accurately estimated the contribution of foods like beef, milk or cheese to overall nutrient intake compared to "as consumed" food categorizations. Some food sources of calories, added sugars and SFA make major contributions to American dietary fiber and micronutrient intakes. Dietary modifications targeting reductions in calories, added sugar, or SFA need to take these key micronutrient sources into account so as not to have the unintended consequence of lowering overall dietary quality.

A method to quantify and value floodplain sediment and nutrient retention ecosystem services

USGS Publications Warehouse

Hopkins, Kristina G.; Noe, Gregory; Franco, Fabiano; Pindilli, Emily J.; Gordon, Stephanie; Metes, Marina J.; Claggett, Peter; Gellis, Allen; Hupp, Cliff R.; Hogan, Dianna

2018-01-01

Floodplains provide critical ecosystem services to local and downstream communities by retaining floodwaters, sediments, and nutrients. The dynamic nature of floodplains is such that these areas can both accumulate sediment and nutrients through deposition, and export material downstream through erosion. Therefore, estimating floodplain sediment and nutrient retention should consider the net flux of both depositional and erosive processes. An ecosystem services framework was used to quantify and value the sediment and nutrient ecosystem service provided by floodplains in the Difficult Run watershed, a small (151 km2) suburban watershed located in the Piedmont of Virginia (USA). A sediment balance was developed for Difficult Run and two nested watersheds. The balance included upland sediment delivery to streams, stream bank flux, floodplain flux, and stream load. Upland sediment delivery was estimated using geospatial datasets and a modified Revised Universal Soil Loss Equation. Predictive models were developed to extrapolate field measurements of the flux of sediment, sediment-bound nitrogen (N), and sediment-bound phosphorus (P) from stream banks and floodplains to 3232 delineated stream segments in the study area. A replacement cost approach was used to estimate the economic value of the sediment and nutrient retention ecosystem service based on estimated net stream bank and floodplain flux of sediment-bound N for all streams in the study area. Results indicated the net fluvial fluxes of sediment, sediment-bound N, and sediment-bound P were −10,439 Mg yr−1 (net export), 57,300 kg-N yr−1(net trapping), and 98 kg-P yr−1(net trapping), respectively. For sediment, floodplain retention was offset by substantial losses from stream bank erosion, particularly in headwater catchments, resulting in a net export of sediment. Nutrient retention in the floodplain exceeded that lost through stream bank erosion resulting in net retention of nutrients (TN and TP). Using a conservative cost estimate of $12.69 (USD) per kilogram of nitrogen, derived from wastewater treatment costs, the estimated annual value for sediment and nutrient retention on Difficult Run floodplains was $727,226 ± 194,220 USD/yr. Values and differences in floodplain nitrogen retention among stream reaches can be used to target areas for floodplain conservation and stream restoration. The methods presented are scalable and transferable to other areas if appropriate datasets are available for validation.

INFLUENCES OF HYDROLOGY ON NUTRIENT DYNAMICS IN LAKE SUPERIOR COASTAL WETLANDS

EPA Science Inventory

Little is known about the role of the coastal wetlands (CWs) of Lake Superior in modifying or contributing to nutrient fluxes from watersheds to the lake. We are studying factors controlling nutrient retention and transformation of CWs in Western Lake Superior. CWs may be unique ...

Oyster reef restoration in controlling coastal pollution around India: A viewpoint.

PubMed

Chakraborty, Parthasarathi

2017-02-15

Coastal waters receive large amounts of nutrients and pollutants from different point and nonpoint sources through bays and estuaries. Excess supply of nutrients in coastal waters may have detrimental effects, leading to hypoxia and anoxia from eutrophication. Reduction in concentrations of excess nutrients/pollutants in bays/estuarine system is must for healthy coastal ecosystem functioning. Conservations of bays, estuaries and coastal zones are must for sustainable development in any maritime country. Excellent ability of oyster in removing and controlling the concentrations of nutrients, pollutants, suspended particulate matters from bays and estuarine waters stimulated me to provide a viewpoint on oyster reef restoration in controlling nutrient/heavy metals fluxes and marine coastal pollution around India. Oyster reefs restoration may decrease nutrient and heavy metals fluxes in coastal waters and reduce the intensity of oxygen depletion in the coastal Arabian Sea (seasonal) and Bay of Bengal. However, extensive research is recommended to understand the impact of oyster reef restoration in controlling coastal pollution which is essential for sustainable development around India. Copyright © 2016 Elsevier Ltd. All rights reserved.

ULK1, Mammalian Target of Rapamycin, and Mitochondria: Linking Nutrient Availability and Autophagy

PubMed Central

2011-01-01

Abstract A fundamental function of autophagy conserved from yeast to mammals is mobilization of macromolecules during times of limited nutrient availability, permitting organisms to survive under starvation conditions. In yeast, autophagy is initiated following nitrogen or carbon deprivation, and autophagy mutants die rapidly under these conditions. Similarly, in mammals, autophagy is upregulated in most organs following initiation of starvation, and is critical for survival in the perinatal period following abrupt termination of the placental nutrient supply. The nutrient-sensing kinase, mammalian target of rapamycin, coordinates cellular proliferation and growth with nutrient availability, at least in part by regulating protein synthesis and autophagy-mediated degradation. This review focusses on the regulation of autophagy by Tor, a mammalian target of rapamycin, and Ulk1, a mammalian homolog of Atg1, in response to changes in nutrient availability. Given the importance of mitochondria in maintaining bioenergetic homestasis, and potentially as a source of membrane for autophagosomes during starvation, possible roles for mitochondria in this process are also discussed. Antioxid. Redox Signal. 14, 1953–1958. PMID:21235397

Nutrient sensing modulates malaria parasite virulence

PubMed Central

Mancio-Silva, Liliana; Slavic, Ksenija; Grilo Ruivo, Margarida T.; Grosso, Ana Rita; Modrzynska, Katarzyna K.; Vera, Iset Medina; Sales-Dias, Joana; Gomes, Ana Rita; MacPherson, Cameron Ross; Crozet, Pierre; Adamo, Mattia; Baena-Gonzalez, Elena; Tewari, Rita; Llinás, Manuel; Billker, Oliver; Mota, Maria M.

2017-01-01

The lifestyle of intracellular pathogens, such as malaria parasites, is intimately connected to that of their host(s), primarily for nutrient supply. Nutrients act not only as primary sources of energy but also as regulators of gene expression, metabolism and growth, through various signaling networks that confer to cells the ability to sense and adapt to varying environmental conditions1,2. Canonical nutrient-sensing pathways are presumably absent in the causing agent of malaria Plasmodium3–5, thus raising the question of whether these parasites possess the capacity to sense and cope with host nutrient fluctuations. Here, we show that Plasmodium blood-stage parasites actively respond to host dietary calorie alterations through a rearrangement of their transcriptome accompanied by a significant adjustment of their multiplication rate. A kinome analysis combined with chemical and genetic approaches identified KIN as a critical regulator that mediates sensing of nutrients and controls a transcriptional response to the host nutritional status. KIN shares homology to SNF1/AMPKα and yeast complementation studies suggest functional conservation of an ancient cellular energy sensing pathway. Overall, these findings reveal a key parasite nutrient-sensing mechanism that is critical to modulate parasite replication and virulence. PMID:28678779

Octopamine connects nutrient cues to lipid metabolism upon nutrient deprivation

PubMed Central

Tao, Jun; Ma, Yi-Cheng; Yang, Zhong-Shan; Zou, Cheng-Gang; Zhang, Ke-Qin

2016-01-01

Starvation is probably the most common stressful situation in nature. In vertebrates, elevation of the biogenic amine norepinephrine levels is common during starvation. However, the precise role of norepinephrine in nutrient deprivation remains largely unknown. We report that in the free-living nematode Caenorhabditis elegans, up-regulation of the biosynthesis of octopamine, the invertebrate counterpart of norepinephrine, serves as a mechanism to adapt to starvation. During nutrient deprivation, the nuclear receptor DAF-12, known to sense nutritional cues, up-regulates the expression of tbh-1 that encodes tyramine β-hydroxylase, a key enzyme for octopamine biosynthesis, in the RIC neurons. Octopamine induces the expression of the lipase gene lips-6 via its receptor SER-3 in the intestine. LIPS-6, in turn, elicits lipid mobilization. Our findings reveal that octopamine acts as an endocrine regulator linking nutrient cues to lipolysis to maintain energy homeostasis, and suggest that such a mechanism may be evolutionally conserved in diverse organisms. PMID:27386520

7 CFR 1466.23 - Payment rates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... conservation practice cost-effectiveness, implementation efficiency, and innovation, (2) The degree and...) Residue management; (B) Nutrient management; (C) Air quality management; (D) Invasive species management; (E) Pollinator habitat development or improvement; (F) Animal carcass management technology; or (G...

Protein kinase A and fungal virulence: a sinister side to a conserved nutrient sensing pathway.

PubMed

Fuller, Kevin K; Rhodes, Judith C

2012-01-01

Diverse fungal species are the cause of devastating agricultural and human diseases. As successful pathogenesis is dependent upon the ability of the fungus to adapt to the nutritional and chemical environment of the host, the understanding of signaling pathways required for such adaptation will provide insights into the virulence of these pathogens and the potential identification of novel targets for antifungal intervention. The cAMP-PKA signaling pathway is well conserved across eukaryotes. In the nonpathogenic yeast, S. cerevisiae, PKA is activated in response to extracellular nutrients and subsequently regulates metabolism and growth. Importantly, this pathway is also a regulator of pathogenesis, as defects in PKA signaling lead to an attenuation of virulence in diverse plant and human pathogenic fungi. This review will compare and contrast PKA signaling in S. cerevisiae vs. various pathogenic species and provide a framework for the role of this pathway in regulating fungal virulence.

Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium.

PubMed

Fernandes, Sheryl Oliveira; Bonin, Patricia C; Michotey, Valérie D; Garcia, Nicole; LokaBharathi, P A

2012-01-01

Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss. However, percentage of total nitrate transformed through complete denitrification accounted for <0-72% of the pore water nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide.

The status of sandy beach science: Past trends, progress, and possible futures

NASA Astrophysics Data System (ADS)

Nel, Ronel; Campbell, Eileen E.; Harris, Linda; Hauser, Lorenz; Schoeman, David S.; McLachlan, Anton; du Preez, Derek R.; Bezuidenhout, Karien; Schlacher, Thomas A.

2014-10-01

Open-ocean sandy beaches are coastal ecosystems with growing relevance in the face of global change. They provide key ecosystem services, such as storm buffering, nutrient cycling, water purification, nursery habitats for resource species, and feeding-breeding habitats for focal species (e.g. endangered sea turtles and shorebirds), and have also become nodes for economic development and cultural use. As a result, beaches face a range of threats, primarily from extractive use, habitat modification and development, sea-level rise and coastal squeeze. Consequently, balancing conservation of the ecosystem and sustainable use of the goods and services is particularly important for sandy shores. Thus, the only way to ensure their protection and continued provision of their valuable services, especially in a period of rapid global change, will be to apply knowledge generated from sound science in beach conservation and management. Here we aim to (1) identify and outline the broad ecological paradigms in sandy beach science; (2) report on a citation analysis of the published literature of the past 63 years (1950-2013) to provide context regarding the topics and location of research, the size and institutional composition of the research teams; and (3) investigate whether beach ecology can and has been incorporated into integrated coastal zone management practices. Past research was framed by specific paradigms (chiefly the Swash Exclusion Hypothesis and derivatives), which can be identified with distinct principles and concepts unique to beaches. Most of the sandy beach literature comes from only a few countries (dominated by USA, South Africa, Brazil and Italy), published by small research teams (<4 authors), mostly from single institutes. The field has yet to establish large multi-disciplinary teams to undertake rigorous experimental science in order to contribute to general ecological theory. Despite the constraints, beach science is responding to new challenges, with increasing use of the latest techniques. However, research in conservation and management specifically remains limited, with stronger focus on anthropogenic impacts, in turn leading to management of people on beaches rather than conservation of the ecosystem itself. We conclude with a look to the future for sandy beach science, and a summary of the contributions to this Special Issue.

Nutrient profiles discriminate between foods according to their contribution to nutritionally adequate diets: a validation study using linear programming and the SAIN,LIM system.

PubMed

Darmon, Nicole; Vieux, Florent; Maillot, Matthieu; Volatier, Jean-Luc; Martin, Ambroise

2009-04-01

The nutrient profile concept implies that it is possible to discriminate between foods according to their contribution to a healthy diet on the basis of their nutrient contents only. The objective was to test the compatibility between nutrient profiling and nutrient-based recommendations by using diet modeling with linear programming. Food consumption data from the French "Individuelle et Nationale sur les Consommations Alimentaires" dietary survey and its associated food-composition database were used as input data. Each food was allocated to 1 of 4 classes, according to the SAIN,LIM system -- a nutrient profiling system based on 2 independent scores, including a total of 8 basic plus 4 optional nutrients. The possibility to model diets fulfilling a set of 40 nutrient recommendations (healthy models) was tested by using foods from a given nutrient profile class only or from a combination of classes. The possibility to fulfill a set of nutrient constraints in contradiction with the recommendations (unhealthy models) was also tested. For each model, the feasible energy range was assessed by minimizing and maximizing total energy content. With foods from the most favorable nutrient profile class, healthy diets could be modeled, but it was impossible to design unhealthy diets within a realistic range of energy intake with these foods. With foods from the least favorable class, unhealthy, but not healthy, diets could be designed. Both healthy and unhealthy diets could be designed with foods from intermediate classes. On the basis of a few key nutrients, it is possible to predict the ability of a given food to facilitate -- or to impair -- the fulfillment of a large number of nutrient recommendations.

Dissolved Nutrient Retention Dynamics in River Networks: A Modeling Investigation of Transient Flow and Scale Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Sheng; Covino, Timothy P.; Sivapalan, Murugesu

In this paper, we use a dynamic network flow model, coupled with a transient storage zone biogeochemical model, to simulate dissolved nutrient removal processes at the channel network scale. We have explored several scenarios in respect of the combination of rainfall variability, and the biological and geomorphic characteristics of the catchment, to understand the dominant controls on removal and delivery of dissolved nutrients (e.g., nitrate). These model-based theoretical analyses suggested that while nutrient removal efficiency is lower during flood events compared to during baseflow periods, flood events contribute significantly to bulk nutrient removal, whereas bulk removal during baseflow periods ismore » less. This is due to the fact that nutrient supply is larger during flood events; this trend is even stronger in large rivers. However, the efficiency of removal during both periods decreases in larger rivers, however, due to (i) increasing flow velocities and thus decreasing residence time, and (ii) increasing flow depth, and thus decreasing nutrient uptake rates. Besides nutrient removal processes can be divided into two parts: in the main channel and in the hyporheic transient storage zone. When assessing their relative contributions the size of the transient storage zone is a dominant control, followed by uptake rates in the main channel and in the transient storage zone. Increasing size of the transient storage zone with downstream distance affects the relative contributions to nutrient removal of the water column and the transient storage zone, which also impacts the way nutrient removal rates scale with increasing size of rivers. Intra-annual hydrologic variability has a significant impact on removal rates at all scales: the more variable the streamflow is, compared to mean discharge, the less nutrient is removed in the channel network. A scale-independent first order uptake coefficient, ke, estimated from model simulations, is highly dependent on the relative size of the transient storage zone and how it changes in the downstream direction, as well as the nature of hydrologic variability.« less

Iron deficiency-induced changes in growth reveal differences in nutrient partitioning between two ecotypes of Medicago truncatula

USDA-ARS?s Scientific Manuscript database

Enhancing the nutritional quality of crops is of international importance, and multiple methods have been utilized to increase the nutrient content of legume seeds. Because nutrients mobilized from source leaves to growing reproductive sink tissues greatly contribute to the final composition of the ...

The importance of submarine groundwater discharge to the nearshore nutrient supply in the Gulf of Aqaba (Israel)

USGS Publications Warehouse

Shellenbarger, G.G.; Monismith, Stephen G.; Genin, A.; Paytan, A.

2006-01-01

We used two short-lived radium isotopes (223Ra, 224Ra) and a mass balance approach applied to the radium activities to determine the nutrient contribution of saline submarine groundwater discharge to the coastal waters of the northern Gulf of Aqaba (Israel). Radium isotope activities were measured along transects during two seasons at a site that lacked any obvious surficial water input. An onshore well and an offshore end member were also sampled. For all samples, nutrients and salinity data were collected. Radium isotope activities generally decreased with distance offshore and exhibited significant tidal variability, which is consistent with a shore-derived tidally influenced source. Submarine groundwater contributes only 1-2% of the water along this coast, but this groundwater provides 8-46% of the nutrients. This saline groundwater is derived predominately from tidally pumped seawater percolating through the unconfined coastal aquifer and leaching radium and nutrients. This process represents a significant source of nutrients to the oligotrophic nearshore reef. ?? 2006, by the American Society of Limnology and Oceanography, Inc.

Spatial Differentiation of Arable Land and Permanent Grasslands to Improve a Regional Land Management Model for Nutrient Balancing

NASA Astrophysics Data System (ADS)

Gómez Giménez, M.; Della Peruta, R.; de Jong, R.; Keller, A.; Schaepman, M. E.

2015-12-01

Agroecosystems play an important role providing economic and ecosystem services, which directly impact society. Inappropriate land use and unsustainable agricultural management with associated nutrient cycles can jeopardize important soil functions such as food production, livestock feeding and conservation of biodiversity. The objective of this study was to integrate remotely sensed land cover information into a regional Land Management Model (LMM) to improve the assessment of spatial explicit nutrient balances for agroecosystems. Remotely sensed data as well as an optimized parameter set contributed to feed the LMM providing a better spatial allocation of agricultural data aggregated at farm level. The integration of land use information in the land allocation process relied predominantly on three factors: i) spatial resolution, ii) classification accuracy and iii) parcels definition. The best-input parameter combination resulted in two different land cover classifications with overall accuracies of 98%, improving the LMM performance by 16% as compared to using non-spatially explicit input. Firstly, the use of spatial explicit information improved the spatial allocation output resulting in a pattern that better followed parcel boundaries (Figure 1). Second, the high classification accuracies ensured consistency between the datasets used. Third, the use of a suitable spatial unit to define the parcels boundaries influenced the model in terms of computational time and the amount of farmland allocated. We conclude that the combined use of remote sensing (RS) data with the LMM has the potential to provide highly accurate information of spatial explicit nutrient balances that are crucial for policy options concerning sustainable management of agricultural soils. Figure 1. Details of the spatial pattern obtained: a) Using only the farm census data, b) using also land use information. Framed in black in the left image (a), examples of artifacts that disappeared when using land use information (right image, b). Colors represent different ownership.

Improving Water Quality With Conservation Buffers

NASA Astrophysics Data System (ADS)

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.

Conservation tillage, optimal water and organic nutrient supply enhance soil microbial activities during wheat (Triticum Aestivum L.) cultivation

PubMed Central

Sharma, Pankaj; Singh, Geeta; Singh, Rana P.

2011-01-01

The field experiments were conducted on sandy loam soil at New Delhi, during 2007 and 2008 to investigate the effect of conservation tillage, irrigation regimes (sub-optimal, optimal and supra-optimal water regimes), and integrated nutrient management (INM) practices on soil biological parameters in wheat cultivation. The conservation tillage soils has shown significant (p<0.05) increase in soil respiration (81.1%), soil microbial biomass carbon (SMBC) (104%) and soil dehydrogenase (DH) (59.2%) compared to the conventional tillage soil. Optimum water supply (3-irrigations) enhanced soil respiration over sub-optimum and supra-optimum irrigations by 13.32% and 79% respectively. Soil dehydrogenase (DH) activity in optimum water regime has also increased by 23.33% and 8.18% respectively over the other two irrigation regimes. Similarly, SMBC has also increased by 12.14% and 27.17% respectively in soil with optimum water supply compared to that of sub-optimum and supra-optimum water regime fields. The maximum increase in soil microbial activities is found when sole organic source (50% Farm Yard Manure+25% biofertilizer+25% Green Manure) has been used in combination with the conservation tillage and the optimum water supply. Study demonstrated that microbial activity could be regulated by tillage, water and nitrogen management in the soil in a sustainable manner. PMID:24031665

Quantifying ocean and ice sheet contributions to nutrient fluxes in Sermilik Fjord, Southeast Greenland

NASA Astrophysics Data System (ADS)

Cape, M. R.; Straneo, F.; Beaird, N.; Bundy, R.; Charette, M. A.

2016-12-01

Meltwater discharged at the margins of the Greenland Ice Sheet (GrIS) represents a potential source of nutrients to biological communities downstream. In Greenland's glacial fjords, this discharge occurs at depth below and along the face of deeply grounded marine-terminating glaciers. This process drives vigorous circulation and mixing between melt and ambient waters at the ice-ocean margins, giving rise to a new glacially modified water mass (GMW) which constitutes the primary vehicle for transport of meltwater in the marine environment. While previous field studies have noted nutrient enrichment in GMW with respect to unmodified waters along the shelf, the source of this enrichment, whether due to entrainment of deep ambient waters or input by meltwater, remains poorly understood. This knowledge is however critical in order to evaluate the current and future contributions of the GrIS to marine biogeochemical cycling. Here we shed light on the distribution, composition, and properties of GMW along the GrIS margin by analyzing integrated physical and chemical measurements collected in August 2015 in Sermilik Fjord, a major glacial freshwater export pathway. Our results document up to a doubling of nutrient concentrations (nitrate, silicate, phosphate, and iron) in GMW, which is distributed in the top 300 m of the water column throughout the fjord. Partitioning of ocean and ice sheet contributions to GMW nutrient load demonstrates that upwelled waters are the primary source of macro-nutrients to GMW. We expand on these results to discuss the magnitude of fluxes in context of previous observations along the GrIS margins, export pathways of GMW to the shelf, and knowledge gaps needed to be addressed to better constrain ice sheet contributions to marine ecosystem processes.

Mechanisms of Bacterial Colonization of the Respiratory Tract

PubMed Central

Siegel, Steven J.; Weiser, Jeffrey N.

2016-01-01

Respiratory tract infections are an important cause of morbidity and mortality worldwide. Chief among these are infections involving the lower airways. The opportunistic bacterial pathogens responsible for most cases of pneumonia can cause a range of local and invasive infections. However, bacterial colonization (or carriage) in the upper airway is the prerequisite of all these infections. Successful colonizers must attach to the epithelial lining, grow on the nutrient-limited mucosal surface, evade the host immune response, and transmit to a susceptible host. Here, we review the molecular mechanisms underlying these conserved stages of carriage. We also examine how the demands of colonization influence progression to disease. A range of bacteria can colonize the upper airway; nevertheless, we focus on strategies shared by many respiratory tract opportunistic pathogens. Understanding colonization opens a window to the evolutionary pressures these pathogens face within their animal hosts and that have selected for attributes that contribute to virulence and pathogenesis. PMID:26488280

HMGB proteins involved in TOR signaling as general regulators of cell growth by controlling ribosome biogenesis.

PubMed

Vizoso-Vázquez, A; Barreiro-Alonso, A; González-Siso, M I; Rodríguez-Belmonte, E; Lamas-Maceiras, M; Cerdán, M E

2018-04-30

The number of ribosomes and their activity need to be highly regulated because their function is crucial for the cell. Ribosome biogenesis is necessary for cell growth and proliferation in accordance with nutrient availability and other external and intracellular signals. High-mobility group B (HMGB) proteins are conserved from yeasts to human and are decisive in cellular fate. These proteins play critical functions, from the maintenance of chromatin structure, DNA repair, or transcriptional regulation, to facilitation of ribosome biogenesis. They are also involved in cancer and other pathologies. In this review, we summarize evidence of how HMGB proteins contribute to ribosome-biogenesis control, with special emphasis on a common nexus to the target of rapamycin (TOR) pathway, a signaling cascade essential for cell growth and proliferation from yeast to human. Perspectives in this field are also discussed.

The Hallmarks of Aging

PubMed Central

López-Otín, Carlos; Blasco, Maria A.; Partridge, Linda; Serrano, Manuel; Kroemer, Guido

2013-01-01

Aging is characterized by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death. This deterioration is the primary risk factor for major human pathologies including cancer, diabetes, cardiovascular disorders, and neurodegenerative diseases. Aging research has experienced an unprecedented advance over recent years, particularly with the discovery that the rate of aging is controlled, at least to some extent, by genetic pathways and biochemical processes conserved in evolution. This review enumerates nine tentative hallmarks that represent common denominators of aging in different organisms, with special emphasis on mammalian aging. These hallmarks are: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. A major challenge is to dissect the interconnectedness between the candidate hallmarks and their relative contribution to aging, with the final goal of identifying pharmaceutical targets to improve human health during aging with minimal side-effects. PMID:23746838

Effect of inorganic nutrients on relative contributions of fungi and bacteria to carbon flow from submerged decomposing leaf litter

Treesearch

Vladislav Gulis; Keller Suberkropp

2003-01-01

The relative contributions of fungi and bacteria to carbon flow from submerged decaying plant litter at different levels of inorganic nutrients (N and P) were studied. We estimated leaf mass loss, fungal and bacterial biomass and production, and microbial respiration and constructed partial carbon budgets for red maple leaf disks precolonized in a stream and then...

Walden Pond, Massachusetts: Environmental Setting and Current Investigations

USGS Publications Warehouse

Colman, John A.; Waldron, Marcus C.

1998-01-01

Introduction Walden Pond, in Concord, Massachusetts, is famous among lakes because of its unique social history. Walden was the setting for American naturalist Henry David Thoreau's well-known essay 'Walden; or, Life in the Woods,' first published in 1854. Thoreau lived and wrote at Walden Pond from July 1845 to September 1847. In 'Walden,' Thoreau combined highly admired writing on Transcendental philosophy with pioneering observations of aquatic ecology and physical aspects of limnology, the study of lakes. Because Thoreau also defended so effectively the value of living close to nature in the Walden woods, the pond is considered by many to be the birthplace of the American conservation movement. Visitors come from all over the world to the pond, which has been designated a National Historic Landmark, and its fame has resulted in a major fund drive to preserve the surrounding woods. Walden Pond has no surfacewater inflow or outflow, and much of its ground-water contributing area likely is preserved within the Walden Pond Reservation area (fig. 1). Only 15 miles from Boston, the pond is unusually clear and pristine for an urban-area lake. However, point sources of nutrients near the pond, and a large annual visitor attendance, concentrated during the summer when the swimming beach (fig. 2) is open, may contribute a nutrient load sufficient to change the pond environment. The occurrence of nuisance algal species, a recent beach closing, and an awareness of water-quality problems suffered by other ponds in the region raise concerns about the risk of ecological change at Walden Pond. Despite the role of Walden Pond as a cultural and environmental icon, little is known about the pond's ecological features, such as its internal nutrient cycling or the structure of its food web, nor have consistent measurements been made to determine whether these features are changing or are stable. Production rates of aquatic plants in lakes and ponds naturally undergo a slow increase as plant nutrients, organic matter, and soil are leached and eroded from the surrounding watershed. This process is known as eutrophication. The term 'cultural eutrophication' refers to an accelerated form of the natural process in which extra soil and nutrients are derived from people's use of fertilizer, rerouting of surface drainage, and disposal of domestic and industrial waste. Cultural eutrophication can lead to excessive growth of aquatic plants, pond filling by decayed plants and eroded soils, reduced water clarity, and depletion of dissolved oxygen in deep water with subsequent loss of cold-water fish habitat. In order to document the longterm ecological health of Walden Pond, the U.S. Geological Survey (USGS), working in cooperation with the Massachusetts Department of Environmental Management (MDEM), is investigating factors that could contribute to cultural eutrophication of Walden. Through measurements of mass balance of nutrients and oxygen in the pond's deep water, the investigation will establish a baseline data set on Walden's trophic state, which is a measure of the pond's ability to support plant growth. The baseline data will be used to detect trends and give early warning of trophic changes or trophic response to pond remediation projects. This Fact Sheet provides background information on the environmental setting, limnological features, and cultural eutrophication of Walden Pond, and describes the joint USGS/MDEM study.

Consistent nutrient storage and supply mediated by diverse fish communities in coral reef ecosystems.

PubMed

Allgeier, Jacob E; Layman, Craig A; Mumby, Peter J; Rosemond, Amy D

2014-08-01

Corals thrive in low nutrient environments and the conservation of these globally imperiled ecosystems is largely dependent on mitigating the effects of anthropogenic nutrient enrichment. However, to better understand the implications of anthropogenic nutrients requires a heightened understanding of baseline nutrient dynamics within these ecosystems. Here, we provide a novel perspective on coral reef nutrient dynamics by examining the role of fish communities in the supply and storage of nitrogen (N) and phosphorus (P). We quantified fish-mediated nutrient storage and supply for 144 species and modeled these data onto 172 fish communities (71 729 individual fish), in four types of coral reefs, as well as seagrass and mangrove ecosystems, throughout the Northern Antilles. Fish communities supplied and stored large quantities of nutrients, with rates varying among ecosystem types. The size structure and diversity of the fish communities best predicted N and P supply and storage and N : P supply, suggesting that alterations to fish communities (e.g., overfishing) will have important implications for nutrient dynamics in these systems. The stoichiometric ratio (N : P) for storage in fish mass (~8 : 1) and supply (~20 : 1) was notably consistent across the four coral reef types (but not seagrass or mangrove ecosystems). Published nutrient enrichment studies on corals show that deviations from this N : P supply ratio may be associated with poor coral fitness, providing qualitative support for the hypothesis that corals and their symbionts may be adapted to specific ratios of nutrient supply. Consumer nutrient stoichiometry provides a baseline from which to better understand nutrient dynamics in coral reef and other coastal ecosystems, information that is greatly needed if we are to implement more effective measures to ensure the future health of the world's oceans. © 2014 John Wiley & Sons Ltd.

Global patterns of dust and bedrock nutrient supply to montane ecosystems

PubMed Central

Arvin, Lindsay J.; Riebe, Clifford S.; Aciego, Sarah M.; Blakowski, Molly A.

2017-01-01

A global compilation of erosion rates and modeled dust fluxes shows that dust inputs can be a large fraction of total soil inputs, particularly when erosion is slow and soil residence time is therefore long. These observations suggest that dust-derived nutrients can be vital to montane ecosystems, even when nutrient supply from bedrock is substantial. We tested this hypothesis using neodymium isotopes as a tracer of mineral phosphorus contributions to vegetation in the Sierra Nevada, California, where rates of erosion and dust deposition are both intermediate within the global compilation. Neodymium isotopes in pine needles, dust, and bedrock show that dust contributes most of the neodymium in vegetation at the site. Together, the global data sets and isotopic tracers confirm the ecological significance of dust in eroding mountain landscapes. This challenges conventional assumptions about dust-derived nutrients, expanding the plausible range of dust-reliant ecosystems to include many temperate montane regions, despite their relatively high rates of erosion and bedrock nutrient supply. PMID:29226246

Horse manure as feedstock for anaerobic digestion.

PubMed

Hadin, Sa; Eriksson, Ola

2016-10-01

Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible. Copyright © 2016. Published by Elsevier Ltd.

Developing unique tracers to distinguish nutrient contributions from agriculture and wastewater sources in the Choptank River and Anacostia River watersheds

USDA-ARS?s Scientific Manuscript database

Eutrophication is a major problem for the Chesapeake Bay ecosystem. The efficacy of the restoration efforts implemented is restricted by the inability to differentiate nutrient sources. This study assessed the use of stable tracers in order to discriminate between urban and agricultural nutrient sou...

Forecasting runoff from Pennsylvania landscapes

USDA-ARS?s Scientific Manuscript database

Identifying sites prone to surface runoff has been a cornerstone of conservation and nutrient management programs, relying upon site assessment tools that support strategic, as opposed to operational, decision making. We sought to develop simple, empirical models to represent two highly different me...

Target of Rapamycin (TOR) in Nutrient Signaling and Growth Control

PubMed Central

Loewith, Robbie; Hall, Michael N.

2011-01-01

TOR (Target Of Rapamycin) is a highly conserved protein kinase that is important in both fundamental and clinical biology. In fundamental biology, TOR is a nutrient-sensitive, central controller of cell growth and aging. In clinical biology, TOR is implicated in many diseases and is the target of the drug rapamycin used in three different therapeutic areas. The yeast Saccharomyces cerevisiae has played a prominent role in both the discovery of TOR and the elucidation of its function. Here we review the TOR signaling network in S. cerevisiae. PMID:22174183

Engineering solutions of environmental problems in organic waste handling

NASA Astrophysics Data System (ADS)

Briukhanov, A. Y.; Vasilev, E. V.; Shalavina, E. V.; Kucheruk, O. N.

2017-10-01

This study shows the urgent need to consider modernization of agricultural production in terms of sustainable development, which takes into account environmental implications of intensive technologies in livestock farming. Some science-based approaches are offered to address related environmental challenges. High-end technologies of organic livestock waste processing were substantiated by the feasibility study and nutrient balance calculation. The technologies were assessed on the basis of best available techniques criteria, including measures such as specific capital and operational costs associated with nutrient conservation and their delivery to the plants.

Garden Documents

EPA Pesticide Factsheets

As a gardener, you have the potential to contribute to nutrient pollution, but you also have the power to help prevent it. There are several easy things you can do to reduce nutrient pollution from your yards and gardens.

Major food sources of calories, added sugars, and saturated fat and their contribution to essential nutrient intakes in the U.S. diet: data from the national health and nutrition examination survey (2003–2006)

PubMed Central

2013-01-01

Background The risk of chronic disease cannot be predicted simply by the content of a single nutrient in a food or food group in the diet. The contribution of food sources of calories, added sugars and saturated fat (SFA) to intakes of dietary fiber and micronutrients of public health importance is also relevant to understanding the overall dietary impact of these foods. Objective Identify the top food sources of calories, added sugars and SFA in the U.S. diet and quantify their contribution to fiber and micronutrient intakes. Methods Single 24-hour dietary recalls (Day 1) collected from participants ≥2 years (n = 16,822) of the What We Eat in America, National Health and Nutrition Examination Survey (WWEIA/NHANES 2003–2006) were analyzed. All analyses included sample weights to account for the survey design. Calorie and nutrient intakes from foods included contributions from disaggregated food mixtures and tabulated by rank order. Results No one food category contributes more than 7.2% of calories to the overall U.S. diet, but half of the top 10 contribute 10% or more of total dietary fiber and micronutrients. Three of the top 10 sources of calories and SFA (beef, milk and cheese) contribute 46.3% of the calcium, 49.5% of the vitamin D, 42.3% of the vitamin B12 as well as other essential nutrients to the American diet. On the other hand, foods categorized as desserts, snacks, or beverages, contribute 13.6% of total calories, 83% of added sugar intake, and provide little or no nutritional value. Including food components of disaggregated recipes more accurately estimated the contribution of foods like beef, milk or cheese to overall nutrient intake compared to “as consumed” food categorizations. Conclusions Some food sources of calories, added sugars and SFA make major contributions to American dietary fiber and micronutrient intakes. Dietary modifications targeting reductions in calories, added sugar, or SFA need to take these key micronutrient sources into account so as not to have the unintended consequence of lowering overall dietary quality. PMID:23927718

Calculating the refractive index for pediatric parenteral nutrient solutions.

PubMed

Nelson, Scott; Barrows, Jason; Haftmann, Richard; Helm, Michael; MacKay, Mark

2013-02-15

The utility of refractometric analysis for calculating the refractive index (RI) of compounded parenteral nutrient solutions for pediatric patients was examined. An equation for calculating the RI of parenteral nutrient solutions was developed by chemical and linear regression analysis of 154 pediatric parenteral nutrient solutions. This equation was then validated by analyzing 1057 pediatric parenteral nutrition samples. The RI for the parenteral nutrient solutions could be calculated by summing the RI contribution for each ingredient and then adding the RI of water. The RI contribution for each ingredient was determined by multiplying the RI of the manufacturer's concentrate by the volume of the manufacturer's concentrate mixed into the parenteral nutrient solution divided by the total volume of the parenteral nutrient solution. The calculated RI was highly correlated with the measured RI (R(2) = 0.94, p < 0.0001). Using a range of two standard deviations (±0.0045), 99.8% of the samples fell into the comparative range. RIs of electrolytes, vitamins, and trace elements in the concentrations used did not affect the RI, similar to the findings of other studies. There was no statistical difference between the calculated RI and the measured RI in the final product of a pediatric parenteral nutrient solution. This method of quality control can be used by personnel compounding parenteral nutrient solutions to confirm the compounding accuracy of dextrose and amino acid concentrations in the final product, and a sample can be sent to the hospital laboratory for electrolyte verification.

The conserved clag multigene family of malaria parasites: essential roles in host-pathogen interaction.

PubMed

Gupta, Ankit; Thiruvengadam, Girija; Desai, Sanjay A

2015-01-01

The clag multigene family is strictly conserved in malaria parasites, but absent from neighboring genera of protozoan parasites. Early research pointed to roles in merozoite invasion and infected cell cytoadherence, but more recent studies have implicated channel-mediated uptake of ions and nutrients from host plasma. Here, we review the current understanding of this gene family, which appears to be central to host-parasite interactions and an important therapeutic target. Published by Elsevier Ltd.

Impacts of climate change on prioritizing conservation areas of hydrological ecosystem services

NASA Astrophysics Data System (ADS)

Lien, Wan Yu; Lin, Yu Pin

2015-04-01

Ecosystem services (ESs) including hydrological services play important roles in our daily life and provide a lot of benefits for human beings from ecological systems. The systems and their services may be threatened by climate change from global to local scales. We herein developed a systematic approach to assess the impacts of climate change on the hydrological ecosystem services, such as water yield, nutrient (nitrogen and phosphorous) retention, and soil retention in a watershed in Northern Taiwan. We first used an ecosystem service evaluation model, InVEST, to estimate the amount and spatial patterns of annual and monthly hydrological ecosystem services under historical weather data, and different climate change scenarios based on five GMSs. The monthly and annual spatiotemporal variations of the ESs were analyzed in this study. Finally, the multiple estimated ESs were considered as the protection conservation targets and regarded as the input data of the systematic conservation planning software, Zonation, to systematically prioritize reserve areas of the ESs under the climate change scenarios. The ES estimation results indicated that the increasing rainfall in wet season leads to the higher water yield and results in the higher sediment and nutrient export indirectly. The Zonation successfully fielded conservation priorities of the ESs. The conservation priorities of the ESs significantly varied spatially and monthly under the climate change scenarios. The ESs results also indicated that the areas where ESs values and conservation priorities with low resilience under climate change should be considered as high priority protected area to ensure the hydrological services in future. Our proposed approach is a novel systematic approach which can be applied to assess impacts of climate change on spatiotemporal variations of ESs as well as prioritize protected area of the ESs under various climate change scenarios. Keyword: climate change, ecosystem service, conservation planning, spatial analysis.

Novel biochar-impregnated calcium alginate beads with improved water holding and nutrient retention properties.

PubMed

Wang, Bing; Gao, Bin; Zimmerman, Andrew R; Zheng, Yulin; Lyu, Honghong

2018-03-01

Drought conditions and nutrients loss have serious impacts on soil quality as well as crop yields in agroecosystems. New techniques are needed to carry out effective soil water and nutrient conservation and fertilizer application tools. Here, calcium alginate (CA) beads impregnated with ball-milled biochar (BMB) were investigated as a new type of water/nutrients retention agent. Both CA and Ca-alginate/ball milled biochar composite (CA-BMB) beads showed high kinetic swelling ratios in KNO 3 solution and low kinetic swelling ratios in water, indicating that CA-BMB beads have the potential to retain mineral nitrogen and nutrients by ion exchange. Pseudo-second-order kinetic model well-described the swelling kinetics of both beads in KNO 3 solution. Over a range of temperatures, the characteristics of dehydration suggested that impregnation with BMB improved the water holding capacity and postponed the dehydration time of Ca-alginate. The cumulative swelling and release characteristics of water, K + , and NO 3 - indicated that CA-BMB beads have great potential as a soil amendment to improve its nutrient retention and water holding capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

The potential contribution of yellow cassava to dietary nutrient adequacy of primary-school children in Eastern Kenya; the use of linear programming.

PubMed

Talsma, Elise F; Borgonjen-van den Berg, Karin J; Melse-Boonstra, Alida; Mayer, Eva V; Verhoef, Hans; Demir, Ayşe Y; Ferguson, Elaine L; Kok, Frans J; Brouwer, Inge D

2018-02-01

Introduction of biofortified cassava as school lunch can increase vitamin A intake, but may increase risk of other deficiencies due to poor nutrient profile of cassava. We assessed the potential effect of introducing a yellow cassava-based school lunch combined with additional food-based recommendations (FBR) on vitamin A and overall nutrient adequacy using Optifood (linear programming tool). Cross-sectional study to assess dietary intakes (24 h recall) and derive model parameters (list of foods consumed, median serving sizes, food and food (sub)group frequency distributions, food cost). Three scenarios were modelled, namely daily diet including: (i) no school lunch; (ii) standard 5d school lunch with maize/beans; and (iii) 5d school lunch with yellow cassava. Each scenario and scenario 3 with additional FBR were assessed on overall nutrient adequacy using recommended nutrient intakes (RNI). Eastern Kenya. Primary-school children (n 150) aged 7-9 years. Best food pattern of yellow cassava-based lunch scenario achieved 100 % RNI for six nutrients compared with no lunch (three nutrients) or standard lunch (five nutrients) scenario. FBR with yellow cassava and including small dried fish improved nutrient adequacy, but could not ensure adequate intake of fat (52 % of average requirement), riboflavin (50 % RNI), folate (59 % RNI) and vitamin A (49 % RNI). Introduction of yellow cassava-based school lunch complemented with FBR potentially improved vitamin A adequacy, but alternative interventions are needed to ensure dietary adequacy. Optifood is useful to assess potential contribution of a biofortified crop to nutrient adequacy and to develop additional FBR to address remaining nutrient gaps.

The spatial variability of nitrogen and phosphorus concentration in a sand aquifer influenced by onsite sewage treatment and disposal systems: a case study on St. George Island, Florida.

PubMed

Corbet, D Reide; Dillon, Kevin; Burnett, William; Schaefer, Geoff

2002-01-01

Groundwater from a shallow freshwater lens on St. George Island, a barrier island located in the Panhandle of Florida, eventually discharges into Apalachicola Bay or the Gulf of Mexico. Nutrient concentrations in groundwaters were monitored downfield from three onsite sewage treatment and disposal systems (OSTDS) on the island. Estimates of natural groundwater nutrient concentrations were obtained from an adjacent uninhabited island. Silicate, which was significantly higher in the imported drinking water relative to the surficial aquifer on St. George Island (12.2+/-1.9 mg Si l(-1) and 2.9+/-0.2 mg Si l(-1), respectively), was used as a natural conservative tracer. Our observations showed that nitrogen concentrations were attenuated to a greater extent than that of phosphorus relative to the conservative tracer. At the current setback distance (23 m), both nitrogen and phosphate concentrations are still elevated above natural levels by as much as 2 and 7 times, respectively. Increasing the setback distance to 50 m and raising the drainfields 1 m above the ground surface could reduce nutrient levels to natural concentrations (1.1+/-0.1 mg N l(-1), 0.20+/-0.02 mg P l(-1)).

7 CFR 1466.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... a contract, and which is operated by the producer with equipment, labor, management, and production... management facility means a structural conservation practice, implemented in the context of a Comprehensive Nutrient Management Plan and consistent with the Field Office Technical Guide, which is used for storing...

Manipulating stomatal density enhances drought tolerance without deleterious effect on nutrient uptake.

PubMed

Hepworth, Christopher; Doheny-Adams, Timothy; Hunt, Lee; Cameron, Duncan D; Gray, Julie E

2015-10-01

Manipulation of stomatal density was investigated as a potential tool for enhancing drought tolerance or nutrient uptake. Drought tolerance and soil water retention were assessed using Arabidopsis epidermal patterning factor mutants manipulated to have increased or decreased stomatal density. Root nutrient uptake via mass flow was monitored under differing plant watering regimes using nitrogen-15 ((15) N) isotope and mass spectrometry. Plants with less than half of their normal complement of stomata, and correspondingly reduced levels of transpiration, conserve soil moisture and are highly drought tolerant but show little or no reduction in shoot nitrogen concentrations especially when water availability is restricted. By contrast, plants with over twice the normal density of stomata have a greater capacity for nitrogen uptake, except when water availability is restricted. We demonstrate the possibility of producing plants with reduced transpiration which have increased drought tolerance, with little or no loss of nutrient uptake. We demonstrate that increasing transpiration can enhance nutrient uptake when water is plentiful. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Defense Coastal/Estuarine Research Program (DCERP) Strategic Plan

DTIC Science & Technology

2007-09-01

atmospheric deposition. The source apportionment of nutrients from atmospheric deposition (especially nitrogen) to estuarine waters derived from direct...migrating wildlife, and nutrient release from soil weathering, atmospheric deposition represents the only source of new nutrients into the... apportionment to properly assess the contributions of off-site and on-site emission sources to regional levels of PM2.5. In preparing this DCERP Strategic

Protecting the Green Behind the Gold: Catchment-Wide Restoration Efforts Necessary to Achieve Nutrient and Sediment Load Reduction Targets in Gold Coast City, Australia

NASA Astrophysics Data System (ADS)

Waltham, Nathan J.; Barry, Michael; McAlister, Tony; Weber, Tony; Groth, Dominic

2014-10-01

The Gold Coast City is the tourist center of Australia and has undergone rapid and massive urban expansion over the past few decades. The Broadwater estuary, in the heart of the City, not only offers an array of ecosystems services for many important aquatic wildlife species, but also supports the livelihood and lifestyles of residents. Not surprisingly, there have been signs of imbalance between these two major services. This study combined a waterway hydraulic and pollutant transport model to simulate diffuse nutrient and sediment loads under past and future proposed land-use changes. A series of catchment restoration initiatives were modeled in an attempt to define optimal catchment scale restoration efforts necessary to protect and enhance the City's waterways. The modeling revealed that for future proposed development, a business as usual approach to catchment management will not reduce nutrient and sediment loading sufficiently to protect the community values. Considerable restoration of upper catchment tributaries is imperative, combined with treatment of stormwater flow from intensively developed sub-catchment areas. Collectively, initiatives undertaken by regulatory authorities to date have successfully reduced nutrient and sediment loading reaching adjoining waterways, although these programs have been ad hoc without strategic systematic planning and vision. Future conservation requires integration of multidisciplinary science and proactive management driven by the high ecological, economical, and community values placed on the City's waterways. Long-term catchment restoration and conservation planning requires an extensive budget (including political and societal support) to handle ongoing maintenance issues associated with scale of restoration determined here.

Pesticide concentrations in frog tissue and wetland habitats in alandscape dominated by agriculture

USGS Publications Warehouse

Smalling, Kelly L.; Reeves, Rebecca; Muths, Erin L.; Vandever, Mark W.; Battaglin, William A.; Hladik, Michelle; Pierce, Clay L.

2015-01-01

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing conservation and management actions for these and similar wetlands in agriculturally dominated landscapes.

Pesticide concentrations in frog tissue and wetland habitats in a landscape dominated by agriculture.

PubMed

Smalling, Kelly L; Reeves, Rebecca; Muths, Erin; Vandever, Mark; Battaglin, William A; Hladik, Michelle L; Pierce, Clay L

2015-01-01

Habitat loss and exposure to pesticides are likely primary factors contributing to amphibian decline in agricultural landscapes. Conservation efforts have attempted to restore wetlands lost through landscape modifications to reduce contaminant loads in surface waters and providing quality habitat to wildlife. The benefits of this increased wetland area, perhaps especially for amphibians, may be negated if habitat quality is insufficient to support persistent populations. We examined the presence of pesticides and nutrients in water and sediment as indicators of habitat quality and assessed the bioaccumulation of pesticides in the tissue of two native amphibian species Pseudacris maculata (chorus frogs) and Lithobates pipiens (leopard frogs) at six wetlands (3 restored and 3 reference) in Iowa, USA. Restored wetlands are positioned on the landscape to receive subsurface tile drainage water while reference wetlands receive water from overland run-off and shallow groundwater sources. Concentrations of the pesticides frequently detected in water and sediment samples were not different between wetland types. The median concentration of atrazine in surface water was 0.2 μg/L. Reproductive abnormalities in leopard frogs have been observed in other studies at these concentrations. Nutrient concentrations were higher in the restored wetlands but lower than concentrations thought lethal to frogs. Complex mixtures of pesticides including up to 8 fungicides, some previously unreported in tissue, were detected with concentrations ranging from 0.08 to 1,500 μg/kg wet weight. No significant differences in pesticide concentrations were observed between species, although concentrations tended to be higher in leopard frogs compared to chorus frogs, possibly because of differences in life histories. Our results provide information on habitat quality in restored wetlands that will assist state and federal agencies, landowners, and resource managers in identifying and implementing conservation and management actions for these and similar wetlands in agriculturally dominated landscapes. Published by Elsevier B.V.

Fluvial fluxes of water, suspended particulate matter, and nutrients and potential impacts on tropical coastal water Biogeochemistry: Oahu, Hawai'i

USGS Publications Warehouse

Hoover, D.J.; MacKenzie, F.T.

2009-01-01

Baseflow and storm runoff fluxes of water, suspended particulate matter (SPM), and nutrients (N and P) were assessed in conservation, urban, and agricultural streams discharging to coastal waters around the tropical island of Oahu, Hawai'i. Despite unusually low storm frequency and intensity during the study, storms accounted for 8-77% (median 30%) of discharge, 57-99% (median 93%) of SPM fluxes, 11-79% (median 36%) of dissolved nutrient fluxes and 52-99% (median 85%) of particulate nutrient fluxes to coastal waters. Fluvial nutrient concentrations varied with hydrologic conditions and land use; land use also affected water and particulate fluxes at some sites. Reactive dissolved N:P ratios typically were ???16 (the 'Redfield ratio' for marine phytoplankton), indicating that inputs could support new production by coastal phytoplankton, but uptake of dissolved nutrients is probably inefficient due to rapid dilution and export of fluvial dissolved inputs. Particulate N and P fluxes were similar to or larger than dissolved fluxes at all sites (median 49% of total nitrogen, range 22-82%; median 69% of total phosphorus, range 49-93%). Impacts of particulate nutrients on coastal ecosystems will depend on how efficiently SPM is retained in nearshore areas, and on the timing and degree of transformation to reactive dissolved forms. Nevertheless, the magnitude of particulate nutrient fluxes suggests that they represent a significant nutrient source for many coastal ecosystems over relatively long time scales (weeks-years), and that reductions in particulate nutrient loading actually may have negative impacts on some coastal ecosystems.

MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

EPA Science Inventory

Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

Amino acids rather than glucose account for the majority of cell mass in proliferating mammalian cells

PubMed Central

Hosios, Aaron M.; Hecht, Vivian C.; Danai, Laura V.; Johnson, Marc O.; Rathmell, Jeffrey C.; Steinhauser, Matthew L.; Manalis, Scott R.; Vander Heiden, Matthew G.

2016-01-01

Cells must duplicate their mass in order to proliferate. Glucose and glutamine are the major nutrients consumed by proliferating mammalian cells, but the extent to which these and other nutrients contribute to cell mass is unknown. We quantified the fraction of cell mass derived from different nutrients and find that the majority of carbon mass in cells is derived from other amino acids, which are consumed at much lower rates than glucose and glutamine. While glucose carbon has diverse fates, glutamine contributes most to protein, and this suggests that glutamine’s ability to replenish TCA cycle intermediates (anaplerosis) is primarily used for amino acid biosynthesis. These findings demonstrate that rates of nutrient consumption are indirectly associated with mass accumulation and suggest that high rates of glucose and glutamine consumption support rapid cell proliferation beyond providing carbon for biosynthesis. PMID:26954548

[Inventory of regional surface nutrient balance and policy recommendations in China].

PubMed

Chen, Min-Peng; Chen, Ji-Ning

2007-06-01

By applying OECD surface soil nitrogen balance methodology, the framework, methodology and database for nutrient balance budget in China are established to evaluate the impact of nutrient balance on agricultural production and water environment. Results show that nitrogen and phosphorus surplus in China are 640 x 10(4) t and 98 x 10(4) t respectively, and nitrogen and phosphorus surplus intensity in China are 16.56 kg/hm2 and 2.53 kg/hm2 respectively. Because of striking spatial difference of nutrient balance across the country, China is seeing a dual-challenge of nutrient surplus management as well as nutrient deficit management. Chemical fertilizer and livestock manure are best targets to perform nutrient surplus management due to their marked contributions to nutrient input. However, it is not cost-effective to implement a uniform management for all regions since nutrient input structures of them vary considerably.

Effects of wastewater irrigation on soil properties and turfgrass growth.

PubMed

Castro, Elena; Mañas, Maria Pilar; De Las Heras, Jorge

2011-01-01

Reuse of treated wastewater for turf irrigation is often viewed as one way to maximize existing urban water resources. The aim of this study is to evaluate the applicability of treated wastewater for turfgrass and assess the effects of continuous use of treated water on the soil and crop. Two turfgrass plots irrigated with drinking water and treated wastewater were monitored over a two-year period. Physical and chemical parameters in the soil and foliar tissue were analyzed. Plants irrigated with treated wastewater had highest sodium content. There were no negative effects with respect to changes in soil pH but a significant increase in electrical conductivity and sodium content was observed in wastewater-irrigated soil. Treated wastewater could be used as a resource for agricultural irrigation since it contributes phosphorus and organic matter. However, it is necessary to consider that several crops could be negatively affected by wastewater irrigation because of the sodium content and this should be taken into account when water-sprinklers are in use, since this is the case in the present study. The benefits of irrigation with treated urban wastewater include contributing plant nutrients to turfgrass while conserving freshwater.

Importance and functions of European grasslands.

PubMed

Carlier, L; De Vliegher, A; Van Cleemput, O; Boeckx, P

2005-01-01

The European agricultural policy is not simple and needs to accommodate also social and environmental requirements. Grassland will continue to be an important form of land use in Europe, but with increased diversity in management objectives and systems used. Besides its role as basic nutrient for herbivores and ruminants grasslands have opportunities for adding value by exploiting positive health characteristics in animal products from grassland and through the delivery of environmental benefits. In fact grasslands contribute to a high degree to the struggle against erosion and to the regularizing of water regimes, to the purification of fertilizers and pesticides and to biodiversity. Finally they have aesthetic role and recreational function as far as they provide public access that other agricultural uses do not allow. But even for grassland it is very difficult to create a good frame for its different tasks (1) the provision of forage for livestock, (2) protection and conservation of soil and water resources, (3) furnishing a habitat for wildlife, both flora and fauna and (4) contribution to the attractiveness of the landscape. Nevertheless it is the only crop, able to fulfil so many tasks and to fit so many requirements.

Detachment and diffusive-convective transport in an evolving heterogeneous two-dimensional biofilm hybrid model.

PubMed

Luna, E; Domínguez-Zacarias, G; Ferreira, C Pio; Velasco-Hernandez, J X

2004-12-01

Under the hypothesis of correlation between biofilm survival and nutrient availability, by considering fluid drag forces and mortality due to nutrient depletion, a biofilm detachment/breaking condition is derived. The mechanisms leading to biofilm detachment/breaking are discussed. We construct and describe a hybrid model for a heterogeneous biofilm attached to walls in a channel where liquid is flowing. The model is called hybrid because it couples conservation equations with a cellular automaton. The biofilm layer is viewed as a porous medium with variable porosity, tortuosity, and permeability. The model is solved using asymptotic and finite differences methods. Results for porosity, nutrient distribution, and average surface location are presented. The model is capable of reproducing biofilm heterogeneity as well as the typical surface fingering (mushroomlike structure).

The short pipe path – safe water, energy & nutrient recovery

EPA Science Inventory

The step-by-step refinement of our urban water systems has yielded unsustainable, centralized urban water services in many developed regions of the world. These large systems also provide the wrong role model and promote conservative thinking for the rapidly developing regions of...

Optimization Tool For Allocation Of Watershed Management Practices For Sediment And Nutrient Control

EPA Science Inventory

Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from nonpoint source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Herein...

Regional gene pools for restoration, conservation, and genetic improvement of prairie grasses

USDA-ARS?s Scientific Manuscript database

Switchgrass (Panicum virgatum), big bluestem (Andropogon gerardii), and Indiangrass (Sorghastrum nutans) are native warm-season grasses that have been identified as potential cellulosic bioenergy feedstock crops due to their potential for high yields, perennial life habit, and nutrient use efficienc...

Evaluation of the phosphorus site assessment tools:lessons from the U.S.

USDA-ARS?s Scientific Manuscript database

Freshwater eutrophication is generally limited or accelerated by phosphorus (P) inputs, with agriculture considered a contributor along with point sources. To help assess the impairments, NRCS incorporated the P Indexing risk assessment tool into the 590 Nutrient Management Conservation Practice St...

Using aquatic vegetation to remediate nitrate, ammonium, and soluble reactive phosphorus in simulated runoff

USDA-ARS?s Scientific Manuscript database

Within the agriculturally-intensive Mississippi River Basin of the United States, significant conservation efforts have focused on management practices that reduce nutrient runoff into receiving aquatic ecosystems. Only a small fraction of those efforts have focused on phytoremediation techniques. ...

Balancing the Needs of China's Wetland Conservation and Rice Production.

PubMed

Chen, Hongjun; Wang, Guoping; Lu, Xianguo; Jiang, Ming; Mendelssohn, Irving A

2015-06-02

China's rice policy for protecting paddy fields and constructing rice production bases is in conflict with its wetland conservation strategy. The policy will increase the rice planting area, the loss of remaining wetlands, and environmental pollution, with intensive application of fertilizers and heavy use of pesticides. The key to resolving this conflict is to bring rice production in compliance with wetland conservation and sustainable agriculture. An operational, sound regulatory program is needed to improve China's wetland conservation. Using wetland conservation in the US as an example, we argue that more effective technical guidelines for wetland inventory and monitoring are necessary to support the implementation of the regulatory program. Agricultural conservation programs are also needed to stop further wetland loss from agricultural usages. An ecoagricultural strategy and practice should be adopted for rice production to reduce pollution and loss of remaining wetlands. Agroecological engineering tools can be used to reduce the impacts of nutrient- and pesticide-enriched agricultural runoff to wetlands.

Nitrogen-limited mangrove ecosystems conserve N through dissimilatory nitrate reduction to ammonium

PubMed Central

Fernandes, Sheryl Oliveira; Bonin, Patricia C.; Michotey, Valérie D.; Garcia, Nicole; LokaBharathi, P. A.

2012-01-01

Earlier observations in mangrove sediments of Goa, India have shown denitrification to be a major pathway for N loss1. However, percentage of total nitrate transformed through complete denitrification accounted for <0–72% of the pore water nitrate reduced. Here, we show that up to 99% of nitrate removal in mangrove sediments is routed through dissimilatory nitrate reduction to ammonium (DNRA). The DNRA process was 2x higher at the relatively pristine site Tuvem compared to the anthropogenically-influenced Divar mangrove ecosystem. In systems receiving low extraneous nutrient inputs, this mechanism effectively conserves and re-circulates N minimizing nutrient loss that would otherwise occur through denitrification. In a global context, the occurrence of DNRA in mangroves has important implications for maintaining N levels and sustaining ecosystem productivity. For the first time, this study also highlights the significance of DNRA in buffering the climate by modulating the production of the greenhouse gas nitrous oxide. PMID:22639727

Food Sources of Total Energy and Nutrients among U.S. Infants and Toddlers: National Health and Nutrition Examination Survey 2005-2012.

PubMed

Grimes, Carley A; Szymlek-Gay, Ewa A; Campbell, Karen J; Nicklas, Theresa A

2015-08-14

Understanding the dietary intakes of infants and toddlers is important because early life nutrition influences future health outcomes. The aim of this study was to determine the dietary sources of total energy and 16 nutrients in a nationally representative sample of U.S. infants and toddlers aged 0-24 months. Data from the 2005-2012 National Health and Nutrition Examination Survey were analyzed. Dietary intake was assessed in 2740 subjects using one 24-h dietary recall. The population proportion was used to determine the contribution of foods and beverages to nutrient intakes. Overall infant formulas and baby foods were the leading sources of total energy and nutrients in infants aged 0-11.9 months. In toddlers, the diversity of food groups contributing to nutrient intakes was much greater. Important sources of total energy included milk, 100% juice and grain based mixed dishes. A number of foods of low nutritional quality also contributed to energy intakes including sweet bakery products, sugar-sweetened beverages and savory snacks. Overall non-flavored milks and ready-to-eat cereals were the most important contributors to micronutrient intakes. In conclusion this information can be used to guide parents regarding appropriate food selection as well as inform targeted dietary strategies within public health initiatives to improve the diets of infants and toddlers.

School lunches in Japan: their contribution to healthier nutrient intake among elementary-school and junior high-school children.

PubMed

Asakura, Keiko; Sasaki, Satoshi

2017-06-01

The role of school lunches in diet quality has not been well studied. Here, we aimed to determine the contribution of school lunches to overall nutrient intake in Japanese schoolchildren. The study was conducted nationwide under a cross-sectional design. A non-consecutive, three-day diet record was performed on two school days and a non-school day separately. The prevalence of inadequate nutrient intake was estimated for intakes on one of the school days and the non-school day, and for daily habitual intake estimated by the best-power method. The relationship between food intake and nutrient intake adequacy was examined. Fourteen elementary and thirteen junior high schools in Japan. Elementary-school children (n 629) and junior high-school children (n 281). Intakes between the school and non-school days were significantly different for ≥60 % of nutrients. Almost all inadequacies were more prevalent on the non-school day. Regarding habitual intake, a high prevalence of inadequacy was observed for fat (29·9-47·7 %), dietary fibre (18·1-76·1 %) and salt (97·0-100 %). Inadequate habitual intake of vitamins and minerals (except Na) was infrequent in elementary-school children, but was observed in junior high-school children, particularly boys. School lunches appear to improve total diet quality, particularly intake of most vitamins and minerals in Japanese children. However, excess intakes of fat and salt and insufficient intake of dietary fibre were major problems in this population. The contribution of school lunches to improving the intakes of these three nutrients was considered insufficient.

Scaling Dissolved Nutrient Removal in River Networks: A Comparative Modeling Investigation

NASA Astrophysics Data System (ADS)

Ye, Sheng; Reisinger, Alexander J.; Tank, Jennifer L.; Baker, Michelle A.; Hall, Robert O.; Rosi, Emma J.; Sivapalan, Murugesu

2017-11-01

Along the river network, water, sediment, and nutrients are transported, cycled, and altered by coupled hydrological and biogeochemical processes. Our current understanding of the rates and processes controlling the cycling and removal of dissolved inorganic nutrients in river networks is limited due to a lack of empirical measurements in large, (nonwadeable), rivers. The goal of this paper was to develop a coupled hydrological and biogeochemical process model to simulate nutrient uptake at the network scale during summer base flow conditions. The model was parameterized with literature values from headwater streams, and empirical measurements made in 15 rivers with varying hydrological, biological, and topographic characteristics, to simulate nutrient uptake at the network scale. We applied the coupled model to 15 catchments describing patterns in uptake for three different solutes to determine the role of rivers in network-scale nutrient cycling. Model simulation results, constrained by empirical data, suggested that rivers contributed proportionally more to nutrient removal than headwater streams given the fraction of their length represented in a network. In addition, variability of nutrient removal patterns among catchments was varied among solutes, and as expected, was influenced by nutrient concentration and discharge. Net ammonium uptake was not significantly correlated with any environmental descriptor. In contrast, net daily nitrate removal was linked to suspended chlorophyll a (an indicator of primary producers) and land use characteristics. Finally, suspended sediment characteristics and agricultural land use were correlated with net daily removal of soluble reactive phosphorus, likely reflecting abiotic sorption dynamics. Rivers are understudied relative to streams, and our model suggests that rivers can contribute more to network-scale nutrient removal than would be expected based upon their representative fraction of network channel length.

Impact of co-digestion on existing salt and nutrient mass balances for a full-scale dairy energy project.

PubMed

Camarillo, Mary Kay; Stringfellow, William T; Spier, Chelsea L; Hanlon, Jeremy S; Domen, Jeremy K

2013-10-15

Anaerobic digestion of manure and other agricultural waste streams with subsequent energy production can result in more sustainable dairy operations; however, importation of digester feedstocks onto dairy farms alters previously established carbon, nutrient, and salinity mass balances. Salt and nutrient mass balance must be maintained to avoid groundwater contamination and salination. To better understand salt and nutrient contributions of imported methane-producing substrates, a mass balance for a full-scale dairy biomass energy project was developed for solids, carbon, nitrogen, sulfur, phosphorus, chloride, and potassium. Digester feedstocks, consisting of thickened manure flush-water slurry, screened manure solids, sudan grass silage, and feed-waste, were tracked separately in the mass balance. The error in mass balance closure for most elements was less than 5%. Manure contributed 69.2% of influent dry matter while contributing 77.7% of nitrogen, 90.9% of sulfur, and 73.4% of phosphorus. Sudan grass silage contributed high quantities of chloride and potassium, 33.3% and 43.4%, respectively, relative to the dry matter contribution of 22.3%. Five potential off-site co-digestates (egg waste, grape pomace, milk waste, pasta waste, whey wastewater) were evaluated for anaerobic digestion based on salt and nutrient content in addition to bio-methane potential. Egg waste and wine grape pomace appeared the most promising co-digestates due to their high methane potentials relative to bulk volume. Increasing power production from the current rate of 369 kW to the design value of 710 kW would require co-digestion with either 26800 L d(-1) egg waste or 60900 kg d(-1) grape pomace. However, importation of egg waste would more than double nitrogen loading, resulting in an increase of 172% above the baseline while co-digestion with grape pomace would increase potassium by 279%. Careful selection of imported co-digestates and management of digester effluent is required to manage salt and nutrient mass loadings and reduce groundwater impacts. Copyright © 2013 Elsevier Ltd. All rights reserved.

75 FR 10025 - Proposed Collection; Comment Request for Regulation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-04

... comments concerning an existing final regulation, LR-200-76 (T.D. 8069), Qualified Conservation... Conservation Contributions. OMB Number: 1545-0763. Regulation Project Number: LR-200-76. Abstract: Internal... charitable contribution for conservation purposes of a partial interest in real property. This regulation...

Tourism and the conservation of critically endangered frogs.

PubMed

Morrison, Clare; Simpkins, Clay; Castley, J Guy; Buckley, Ralf C

2012-01-01

Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5-100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8-99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts.

Tourism and the Conservation of Critically Endangered Frogs

PubMed Central

Morrison, Clare; Simpkins, Clay; Castley, J. Guy; Buckley, Ralf C.

2012-01-01

Protected areas are critical for the conservation of many threatened species. Despite this, many protected areas are acutely underfunded, which reduces their effectiveness significantly. Tourism is one mechanism to promote and fund conservation in protected areas, but there are few studies analyzing its tangible conservation outcomes for threatened species. This study uses the 415 IUCN critically endangered frog species to evaluate the contribution of protected area tourism revenue to conservation. Contributions were calculated for each species as the proportion of geographic range inside protected areas multiplied by the proportion of protected area revenues derived from tourism. Geographic ranges were determined from IUCN Extent of Occurrence maps. Almost 60% (239) of critically endangered frog species occur in protected areas. Higher proportions of total range are protected in Nearctic, Australasian and Afrotopical regions. Tourism contributions to protected area budgets ranged from 5–100%. These financial contributions are highest for developing countries in the Afrotropical, Indomalayan and Neotropical regions. Data for both geographic range and budget are available for 201 critically endangered frog species with proportional contributions from tourism to species protection ranging from 0.8–99%. Tourism's financial contributions to critically endangered frog species protection are highest in the Afrotropical region. This study uses a coarse measure but at the global scale it demonstrates that tourism has significant potential to contribute to global frog conservation efforts. PMID:22984440

Carcass analog provides marine subsidies for macroinvertebrates and juvenile Atlantic 8 salmon in temperate oligotrophic streams

USGS Publications Warehouse

Guyette, Margaret Q.; Loftin, Cynthia S.; Zydlewski, Joseph D.; Cunjak, Richard

2014-01-01

Assimilation of nutrients from carcass analogues was both direct and indirect, and a nutrient legacy was evident in the second year of sampling. Incorporation of nutrients from the pellets at a range of heights in the food web demonstrated the potential for marine-derived subsidies to contribute to freshwater ecosystem processes in Atlantic salmon nursery streams.

Effects of nutrient management on nitrate levels in ground water near Ephrata Pennsylvania

USGS Publications Warehouse

Hall, David W.

1992-01-01

Effects of the implementation of nutrient management practices on ground-water quality were studied at a 55-acre farm in Lancaster County, Pennsylvania, from 1985-90. After nutrient management practices were implemented at the site in October 1986, statistically significant decreases (Wilcoxon Mann-Whitney test) in median nitrate concentrations in ground-water samples occurred at four of the five wells monitored. The largest decreases in nitrate concentration occurred in samples collected at the wells that had the largest nitrate concentrations prior to nutrient management. The decreases in median nitrate concentrations in ground-water samples ranged from 8 to 32 percent of the median concentrations prior to nutrient management and corresponded to nitrogen application decreases of 39 to 67 percent in contributing areas that were defined upgradient of these wells. Changes in nitrogen applications to the contributing areas of five water wells were correlated (Spearman rank-sum test) with nitrate concentrations of the well water. Changes in ground-water nitrate concentrations lagged behind the changes in applied-nitrogen fertilizers (primarily manure) by approximately 4 to 19 months.

Contribution of cod liver oil-related nutrients (vitamins A, D, E and eicosapentaenoic acid and docosahexaenoic acid) to daily nutrient intake and their associations with plasma concentrations in the EPIC-Norfolk cohort

PubMed Central

Lentjes, M A H; Mulligan, A A; Welch, A A; Bhaniani, A; Luben, R N; Khaw, K–T

2015-01-01

Background Total nutrient intake (TNI) is intake from food and supplements. This provides an assessment of nutrient adequacy and the prevalence of excessive intake, as well as the response with respect to biomarkers. Cod liver oil (CLO) is the most frequently consumed supplement in the UK, containing nutrients that might have varying influences on health. We calculated TNI for vitamins A, D and E, as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and assessed associations with the respective blood concentrations. Methods Seven-day diet diaries and blood samples were taken from two subsets of the European Prospective Investigation into Cancer (EPIC-Norfolk) cohort (age range 39–79 years; n = 1400 for vitamin D; n = 6656 for remaining nutrients). TNI was calculated for the subgroups: nonsupplement users, those consuming the nutrient in supplement form and those consuming a supplement without this nutrient. Results CLO-related nutrients were supplemented by 15%–33%, which approximately doubled median intakes. Almost everyone in the supplement + vitamin A group reached the estimated average requirement; however, guideline levels were likely to be exceeded. Partial correlations between intake of vitamins A and D and biomarkers were low and modestly strengthened by the inclusion of supplement sources (correlation = 0.01–0.13). Correlations between biomarker and TNI of vitamin E and EPA+DHA were in the range 0.40–0.46; however, vitamin E exceeding food intake resulted in attenuated coefficients. Linear associations between food or TNI EPA+DHA and plasma were weak but consistent across subgroups. Conclusions CLO-related nutrients contribute substantially to nutrient intake, with a risk of over-consumption. Apart from EPA+DHA, biomarker data suggest that CLO-related nutrients in supplements are not linearly associated with vitamin status. PMID:25228113

Contribution of cod liver oil-related nutrients (vitamins A, D, E and eicosapentaenoic acid and docosahexaenoic acid) to daily nutrient intake and their associations with plasma concentrations in the EPIC-Norfolk cohort.

PubMed

Lentjes, M A H; Mulligan, A A; Welch, A A; Bhaniani, A; Luben, R N; Khaw, K-T

2015-12-01

Total nutrient intake (TNI) is intake from food and supplements. This provides an assessment of nutrient adequacy and the prevalence of excessive intake, as well as the response with respect to biomarkers. Cod liver oil (CLO) is the most frequently consumed supplement in the UK, containing nutrients that might have varying influences on health. We calculated TNI for vitamins A, D and E, as well as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and assessed associations with the respective blood concentrations. Seven-day diet diaries and blood samples were taken from two subsets of the European Prospective Investigation into Cancer (EPIC-Norfolk) cohort (age range 39-79 years; n = 1400 for vitamin D; n = 6656 for remaining nutrients). TNI was calculated for the subgroups: nonsupplement users, those consuming the nutrient in supplement form and those consuming a supplement without this nutrient. CLO-related nutrients were supplemented by 15%-33%, which approximately doubled median intakes. Almost everyone in the supplement + vitamin A group reached the estimated average requirement; however, guideline levels were likely to be exceeded. Partial correlations between intake of vitamins A and D and biomarkers were low and modestly strengthened by the inclusion of supplement sources (correlation = 0.01-0.13). Correlations between biomarker and TNI of vitamin E and EPA+DHA were in the range 0.40-0.46; however, vitamin E exceeding food intake resulted in attenuated coefficients. Linear associations between food or TNI EPA+DHA and plasma were weak but consistent across subgroups. CLO-related nutrients contribute substantially to nutrient intake, with a risk of over-consumption. Apart from EPA+DHA, biomarker data suggest that CLO-related nutrients in supplements are not linearly associated with vitamin status. © 2014 Authors. Journal of Human Nutrition and Dietetics published by John Wiley & Sons Ltd on behalf of British Dietetic Association.

Testing consumer perception of nutrient content claims using conjoint analysis.

PubMed

Drewnowski, Adam; Moskowitz, Howard; Reisner, Michele; Krieger, Bert

2010-05-01

The US Food and Drug Administration (FDA) proposes to establish standardized and mandatory criteria upon which front-of-pack (FOP) nutrition labelling must be based. The present study aimed to estimate the relative contribution of declared amounts of different nutrients to the perception of the overall 'healthfulness' of foods by the consumer. Protein, fibre, vitamin A, vitamin C, calcium and iron were nutrients to encourage. Total fat, saturated fat, cholesterol, total and added sugar, and sodium were the nutrients to limit. Two content claims per nutrient used the FDA-approved language. An online consumer panel (n 320) exposed to multiple messages (n 48) rated the healthfulness of each hypothetical food product. Utility functions were constructed using conjoint analysis, based on multiple logistic regression and maximum likelihood estimation. Consumer perception of healthfulness was most strongly driven by the declared presence of protein, fibre, calcium and vitamin C and by the declared total absence of saturated fat and sodium. For this adult panel, total and added sugar had lower utilities and contributed less to the perception of healthfulness. There were major differences between women and men. Conjoint analysis can lead to a better understanding of how consumers process information about the full nutrition profile of a product, and is a powerful tool for the testing of nutrient content claims. Such studies can help the FDA develop science-based criteria for nutrient profiling that underlies FOP and shelf labelling.

Identification, Expression Analysis, and Target Prediction of Flax Genotroph MicroRNAs Under Normal and Nutrient Stress Conditions

PubMed Central

Melnikova, Nataliya V.; Dmitriev, Alexey A.; Belenikin, Maxim S.; Koroban, Nadezhda V.; Speranskaya, Anna S.; Krinitsina, Anastasia A.; Krasnov, George S.; Lakunina, Valentina A.; Snezhkina, Anastasiya V.; Sadritdinova, Asiya F.; Kishlyan, Natalya V.; Rozhmina, Tatiana A.; Klimina, Kseniya M.; Amosova, Alexandra V.; Zelenin, Alexander V.; Muravenko, Olga V.; Bolsheva, Nadezhda L.; Kudryavtseva, Anna V.

2016-01-01

Cultivated flax (Linum usitatissimum L.) is an important plant valuable for industry. Some flax lines can undergo heritable phenotypic and genotypic changes (LIS-1 insertion being the most common) in response to nutrient stress and are called plastic lines. Offspring of plastic lines, which stably inherit the changes, are called genotrophs. MicroRNAs (miRNAs) are involved in a crucial regulatory mechanism of gene expression. They have previously been assumed to take part in nutrient stress response and can, therefore, participate in genotroph formation. In the present study, we performed high-throughput sequencing of small RNAs (sRNAs) extracted from flax plants grown under normal, phosphate deficient and nutrient excess conditions to identify miRNAs and evaluate their expression. Our analysis revealed expression of 96 conserved miRNAs from 21 families in flax. Moreover, 475 novel potential miRNAs were identified for the first time, and their targets were predicted. However, none of the identified miRNAs were transcribed from LIS-1. Expression of seven miRNAs (miR168, miR169, miR395, miR398, miR399, miR408, and lus-miR-N1) with up- or down-regulation under nutrient stress (on the basis of high-throughput sequencing data) was evaluated on extended sampling using qPCR. Reference gene search identified ETIF3H and ETIF3E genes as most suitable for this purpose. Down-regulation of novel potential lus-miR-N1 and up-regulation of conserved miR399 were revealed under the phosphate deficient conditions. In addition, the negative correlation of expression of lus-miR-N1 and its predicted target, ubiquitin-activating enzyme E1 gene, as well as, miR399 and its predicted target, ubiquitin-conjugating enzyme E2 gene, was observed. Thus, in our study, miRNAs expressed in flax plastic lines and genotrophs were identified and their expression and expression of their targets was evaluated using high-throughput sequencing and qPCR for the first time. These data provide new insights into nutrient stress response regulation in plastic flax cultivars. PMID:27092149

78 FR 22036 - Proposed Collection; Comment Request for Regulation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-12

... fair market value of the underlying property before and after the donation and (2) the conservation... qualified conservation contributions (Sec. 1.170A-14). DATES: Written comments should be received on or... INFORMATION: Title: Qualified Conservation Contributions. OMB Number: 1545-0763. Regulation Project Number: TD...

Contribution of forest foods to dietary intake and their association with household food insecurity: a cross-sectional study in women from rural Cameroon.

PubMed

Fungo, Robert; Muyonga, John; Kabahenda, Margaret; Kaaya, Archileo; Okia, Clement A; Donn, Pauline; Mathurin, Tchatat; Tchingsabe, Obadia; Tiegehungo, Julius C; Loo, Judy; Snook, Laura

2016-12-01

To determine the contribution of forest foods to dietary intake and estimate their association with household food insecurity. Cross-sectional survey conducted among 279 households. Using a 7 d recall questionnaire, information on household food consumption was collected from women and used to determine the household dietary diversity score, food variety score and forest food consumption score (FFCS). Household Food Insecurity Access Scale (HFIAS) score was determined and Spearman rank correlation was used to establish the relationship between consumption of forest foods and HFIAS score. Women's dietary intake was estimated from two 24 h recalls. The contribution of forest foods to women's nutrient intakes was calculated and women's nutrient intakes were compared with estimated average nutrient requirements. Rural forest-dependent households in twelve villages in eastern and southern Cameroon. Household heads and their non-pregnant, non-lactating spouses. Forty-seven unique forest foods were identified; of these, seventeen were consumed by 98 % of respondents over the course of one week and by 17 % of women during the two 24 h recall periods. Although forest foods contributed approximately half of women's total daily energy intake, considerably greater contributions were made to vitamin A (93 %), Na (100 %), Fe (85 %), Zn (88 %) and Ca (89 %) intakes. Despite a highly biodiverse pool of foods, most households (83 %) suffered from high food insecurity based on the HFIAS. A significant inverse correlation was observed between the HFIAS score and the FFCS (r 2=-0·169, P=0·0006), demonstrating that forest foods play an important role in ensuring food security in these forest-dependent communities. Forest foods are widely consumed by forest-dependent communities. Given their rich nutrient content, they have potential to contribute to food and nutrition security.

Benthic algal production across lake size gradients: interactions among morphometry, nutrients, and light.

PubMed

Vadeboncoeur, Yvonne; Peterson, Garry; Vander Zanden, M Jake; Kalff, Jacob

2008-09-01

Attached algae play a minor role in conceptual and empirical models of lake ecosystem function but paradoxically form the energetic base of food webs that support a wide variety of fishes. To explore the apparent mismatch between perceived limits on contributions of periphyton to whole-lake primary production and its importance to consumers, we modeled the contribution of periphyton to whole-ecosystem primary production across lake size, shape, and nutrient gradients. The distribution of available benthic habitat for periphyton is influenced by the ratio of mean depth to maximum depth (DR = z/ z(max)). We modeled total phytoplankton production from water-column nutrient availability, z, and light. Periphyton production was a function of light-saturated photosynthesis (BPmax) and light availability at depth. The model demonstrated that depth ratio (DR) and light attenuation strongly determined the maximum possible contribution of benthic algae to lake production, and the benthic proportion of whole-lake primary production (BPf) declined with increasing nutrients. Shallow lakes (z < or =5 m) were insensitive to DR and were dominated by either benthic or pelagic primary productivity depending on trophic status. Moderately deep oligotrophic lakes had substantial contributions by benthic primary productivity at low depth ratios and when maximum benthic photosynthesis was moderate or high. Extremely large, deep lakes always had low fractional contributions of benthic primary production. An analysis of the world's largest lakes showed that the shapes of natural lakes shift increasingly toward lower depth ratios with increasing depth, maximizing the potential importance of littoral primary production in large-lake food webs. The repeatedly demonstrated importance of periphyton to lake food webs may reflect the combination of low depth ratios and high light penetration characteristic of large, oligotrophic lakes that in turn lead to substantial contributions of periphyton to autochthonous production.

CHARACTERIZATION OF A LIBRARY OF MONOCLONAL ANTIBODIES AGAINST VITELLOGENIN: CONSERVATION OF EPITOPES

EPA Science Inventory

The egg yolk precursor, vitellogenin, a complex phospho-lipo-glycoprotein, is the main source of nutrients for the developing embryo of all oviparous animals. Because of this role it has few evolutionary constraints imposed on its structure, varying widely among species. Despite ...

Comparison of chemical attractants against dung beetles and application for rangeland and animal health

USDA-ARS?s Scientific Manuscript database

Dung beetles (Coleoptera: Scarabaeidae) play a major role in nutrient cycling, soil aeration, and biological control of pests and parasites that breed in manure. Habitat fragmentation, pesticide usage, and conventional agricultural practices threaten dung beetle diversity, and their conservation is ...

Fall cover crops boost soil arbuscular mycorrhizal fungi which can lead to reduced inputs

USDA-ARS?s Scientific Manuscript database

Fall cover crops provide multiple benefits to producers. These benefits include pathogen and pest protection, drought protection, weed control, reduced soil erosion, nutrient acquisition and retention, increased soil organic matter, and conservation of soil water by improvement of soil structure th...

Nutrient Credit Trading--a Market-based Approach for Improving Water Quality

USDA-ARS?s Scientific Manuscript database

Farmers are getting financial rewards for implementing conservation measures on their farms. Industrial wastewater treatment plants are buying credits generated from these measures to meet their NPDES permit regulatory requirements. This is referred to as “water quality trading.” The treatment p...

Mechanistic modeling & effectiveness of buffer strips for pesticide regulatory frameworks

USDA-ARS?s Scientific Manuscript database

Vegetative Filter Strips (VFS) have been used as an effective conservation practice in agricultural areas for controlling and mitigate the effect of sediment, nutrients and pesticides loads into water bodies. In addition to the agricultural sector, another important use of VFS for controlling plague...

Evolving urban water and residuals management paradigms: water reclamation and reuse, decentralization, and resource recovery.

PubMed

Daigger, Glen T

2009-08-01

Population growth and improving standards of living, coupled with dramatically increased urbanization, are placing increased pressures on available water resources, necessitating new approaches to urban water management. The tradition linear "take, make, waste" approach to managing water increasingly is proving to be unsustainable, as it is leading to water stress (insufficient water supplies), unsustainable resource (energy and chemicals) consumption, the dispersion of nutrients into the aquatic environment (especially phosphorus), and financially unstable utilities. Different approaches are needed to achieve economic, environmental, and social sustainability. Fortunately, a toolkit consisting of stormwater management/rainwater harvesting, water conservation, water reclamation and reuse, energy management, nutrient recovery, and source separation is available to allow more closed-loop urban water and resource management systems to be developed and implemented. Water conservation and water reclamation and reuse (multiple uses) are becoming commonplace in numerous water-short locations. Decentralization, enabled by new, high-performance treatment technologies and distributed stormwater management/rainwater harvesting, is furthering this transition. Likewise, traditional approaches to residuals management are evolving, as higher levels of energy recovery are desired, and nutrient recovery and reuse is to be enhanced. A variety of factors affect selection of the optimum approach for a particular urban area, including local hydrology, available water supplies, water demands, local energy and nutrient-management situations, existing infrastructure, and utility governance structure. A proper approach to economic analysis is critical to determine the most sustainable solutions. Stove piping (i.e., separate management of drinking, storm, and waste water) within the urban water and resource management profession must be eliminated. Adoption of these new approaches to urban water and resource management can lead to more sustainable solutions, defined as financially stable, using locally sustainable water supplies, energy-neutral, providing responsible nutrient management, and with access to clean water and appropriate sanitation for all.

[Impact of tillage and nutrient management practices on the spring weed community in a winter wheat-summer maize rotation farmland].

PubMed

Wang, Neng Wei; Ge, Xiu Li; Li, Sheng Dong

2017-03-18

Conservation tillage and the weed diversity are two hot issues in the modern ecological agriculture. Although it is known that the diversity of weed would increase slightly in the farmland under conservation tillage, the interaction effects between the tillage and the nutrient management on the weed community are not clear. In this study, one wheat-maize rotation field located in Ji'nan, Shandong Province, was selected as the studying site. Different tillage methods (no-tillage, deep subsoiling, rotary tillage, deep tillage) and different nutrient managements (farmers routine, 480 kg N hm -2 per year; high production and efficiency, 360 kg N hm -2 per year; optimal management, 300 kg N hm -2 per year) were carried out for 3 years. The characteristics of the spring weed communities under different managements were investigated and compared. The results showed that there were 15 species in the spring weed communities in the test filed and Digitaria sanguinalis and Echinochloa crusgalli were the dominant species. The plots under no-tillage or deep subsoiling had higher weed densities compared with those under the deep tillage or rotary tillage. In terms of the effect of tillage on the weed community diversity, both species richness index and species evenness index were lowest but the community dominance index was highest in the plots under deep tillage. In terms of the effect of the nutrient management, with the increase of fertilizer application, both species richness and evenness index increased under the different tillage methods. The community dominance increased with the increasing fertilizer application under deep tillage or rotary tillage and vice versa under no-tillage, deep subsoiling. In terms of weed biomass, the plots under no-tillage or deep subsoiling had significantly higher weed biomass than those under the other two tillage methods. The plots under routine nutrient management had higher weed biomass than those under the other two nutrient managements. Among all these treatments, the plots under the combination treatment of no-tillage and routine nutrient management had the highest weed biomass. According to these results, it was implied that no-tillage and fertilization would improve species richness index, species evenness index, and the productivity of spring weed community in the wheat-maize farmland.

Spatial and temporal variation of stream chemistry associated with contrasting geology and land-use patterns in the Chesapeake Bay watershed—Summary of results from Smith Creek, Virginia; Upper Chester River, Maryland; Conewago Creek, Pennsylvania; and Difficult Run, Virginia, 2010–2013

USGS Publications Warehouse

Hyer, Kenneth E.; Denver, Judith M.; Langland, Michael J.; Webber, James S.; Böhlke, J.K.; Hively, W. Dean; Clune, John W.

2016-11-17

Despite widespread and ongoing implementation of conservation practices throughout the Chesapeake Bay watershed, water quality continues to be degraded by excess sediment and nutrient inputs. While the Chesapeake Bay Program has developed and maintains a large-scale and long-term monitoring network to detect improvements in water quality throughout the watershed, fewer resources have been allocated for monitoring smaller watersheds, even though water-quality improvements that may result from the implementation of conservation practices are likely to be first detected at smaller watershed scales.In 2010, the U.S. Geological Survey partnered with the U.S. Environmental Protection Agency and the U.S. Department of Agriculture to initiate water-quality monitoring in four selected small watersheds that were targeted for increased implementation of conservation practices. Smith Creek watershed is an agricultural watershed in the Shenandoah Valley of Virginia that is dominated by cattle and poultry production, and the Upper Chester River watershed is an agricultural watershed on the Eastern Shore of Maryland that is dominated by row-cropping activities. The Conewago Creek watershed is an agricultural watershed in southeastern Pennsylvania that is characterized by mixed agricultural activities. The fourth watershed, Difficult Run, is a suburban watershed in northern Virginia that is dominated by medium density residential development. The objective of this study was to investigate spatial and temporal variations in water chemistry and suspended sediment in these four relatively small watersheds that represent a range of land-use patterns and underlying geology to (1) characterize current water-quality conditions in these watersheds, and (2) identify the dominant sources, sinks, and transport processes in each watershed.The general study design involved two components. The first included intensive routine water-quality monitoring at an existing streamgage within each study area (including continuous water-quality monitoring as well as discrete water-quality sampling) to develop a detailed understanding of the temporal and hydrologic variability in stream chemistry and sediment transport in each watershed. The second component involved extensive water-quality monitoring at various sites throughout each watershed to develop a detailed understanding of spatial patterns. Both components were used to improve understanding of sources and transport processes affecting stream chemistry, including nutrients and suspended sediments, and their implications for detecting long-term trends related to best management practices. This report summarizes the results of monitoring that was performed from April 2010 through September 2013.Individual Small Watershed SummariesSummaries for each of the four small watersheds are presented below. Each watershed has a more descriptive and detailed section in the report, but these summaries may be particularly useful for some watershed managers and stakeholders desiring slightly less technical detail.Smith CreekSmith Creek is a 105.39-mi2 watershed within the Shenandoah Valley that drains to the North Fork Shenandoah River. The long-term Smith Creek base-flow index is 72.3 percent, indicating that on average, approximately 72 percent of Smith Creek flow was base flow, which suggests that Smith Creek streamflow is dominated by groundwater discharge rather than stormwater runoff. A series of cluster and principal components analyses demonstrated that the majority of the variability in Smith Creek water quality could be attributed to hydrologic and seasonal variability. Statistically significant positive correlations with flow were observed for turbidity, suspended sediments, total nitrogen, ammonium, orthophosphate, iron, total phosphorus, and the ratio of calcium to magnesium. Statistically significant inverse correlations with flow were observed for specific conductance, magnesium, δ15N of nitrate, pH, bicarbonate, calcium, and δ18O of nitrate. Of particular note, flow and nitrate were not statistically significantly correlated, likely because of the relatively complex concentration-discharge relationship observed in continuous and discrete datasets. Statistically significant seasonal patterns were observed for numerous water-quality constituents: water temperature, turbidity, orthophosphate, total phosphorus, suspended-sediment concentration, and silica were higher during the warm season, but pH, dissolved oxygen, and sulfate were higher during the cool season. Surrogate regression models were developed to compute sediment and nutrient loads in Smith Creek using the continuous water-quality monitors. The mean Smith Creek in-stream sediment load was approximately 6,900 tons per year, with nearly 90 percent of the sediment load over the 3-year study period contributed during the eight largest storm events during that period. The Smith Creek total phosphorus load was approximately 21,000 pounds of phosphorus per year, with the majority of the load contributed during stormflow periods, although a substantial phosphorus load still occurs during base-flow conditions. The Smith Creek total nitrogen load was approximately 400,000 pounds per year, with total nitrogen accumulation less dominated by stormflow contributions (as was the case for sediment and total phosphorus) and strongly affected by base-flow export of nitrogen from the basin.Extensive water-quality monitoring throughout the Smith Creek watershed revealed how the complex geology and hydrology interacted to result in variable water chemistry. During relatively dry and low base-flow periods, much of the discharge in Smith Creek was contributed by a single dominant spring—Lacey Spring. During wetter base-flow periods, the flows in Smith Creek were largely generated by a mixture of headwater springs and forested mountain tributaries with very different geochemical composition. The headwater springs generally issued from limestone bedrock and were characterized as having relatively high nitrate, specific conductance, calcium, and magnesium, as well as relatively low concentrations of phosphorus, ammonium, iron, and manganese. The undeveloped, high-gradient, forested mountain sites were generally characterized by low ionic strength waters with low nutrient concentrations. Nitrate isotope data from the limestone springs generally were consistent with manure-derived nitrogen sources (such as cattle and poultry), although the possibility of other mixed sources cannot be excluded. Nitrate isotope data from the undeveloped, high-gradient forested mountain sites were more consistent with nitrogen from undisturbed soils, atmospheric deposition, or nitrogen fixation. Regardless of the nitrogen source, oxygen isotope data indicate that the nitrate was largely a result of nitrification. Land-use data indicate that manure sources of nitrogen dominated watershed nitrogen inputs. Phosphorus sources were less well studied. The presence of a single point-source discharge near the town of New Market contributed the majority of the phosphorus to Smith Creek under base-flow conditions, but nonpoint sources of phosphorus dominated the loading to Smith Creek during stormflow periods.Implementation of conservation practices increased in the Smith Creek watershed during the study period, and even though a broad range of practice types was implemented, the most common practices included stream fencing (for cattle exclusion), the development of nutrient management plans, conservation crop rotation, and the planting of cover crops. While the implementation of these conservation practices is encouraging, results indicate small increases in nitrate concentrations at the streamgage over the last 29 years, concurrent with small decreases in nitrate fluxes. It will likely be years before the cumulative effect of these practices can be detected in the Smith Creek water quality, and the magnitude of the effect of these conservation practices detected in Smith Creek will depend largely on whether nutrient loading (of manure and commercial fertilizer) is reduced over time.Upper Chester RiverThe Upper Chester River watershed includes the 36-square-mile (mi2) watershed area around several nontidal tributaries that drain into the tidal Chester River. The streamgage is on Chesterville Branch, the largest nontidal tributary (approximately 6.12 mi2) and is the site for continuous water-quality monitoring for this project. The base-flow index at Chesterville Branch is about 72 percent and indicates that, as in most of the Coastal Plain, groundwater is the greatest contributor to streamflow. As such, more than 90 percent of the nitrogen in the stream is in the form of nitrate from groundwater. Continuous and discrete data collected at Chesterville Branch show the effects of streamflow and season on water quality. Significantly positive correlations with flow were observed for ammonium, dissolved and total phosphorus, sediment, and turbidity as runoff carried these constituents from the land surface into Chesterville Branch. Other constituents that increased significantly with flow include potassium, sulfate, iron, and manganese, which are likely contributed from near-stream areas and ponds with high organic-matter content. Total nitrogen, pH, and specific conductance, along with chemical constituents associated with groundwater inputs including nitrate, calcium, ratio of calcium to magnesium, silica, bicarbonate, and sodium, were negatively correlated with flow because concentrations of these constituents were diluted by runoff.Seasonal differences in water chemistry, which are most likely related to increased biologic effects on the uptake and release of chemicals in the stream and near-stream areas, also were observed. Water temperature, orthophosphate, δ15N of nitrate, bicarbonate, sodium, and the ratio of sodium to chloride were higher during the warm season, and dissolved oxygen, total nitrogen, nitrate, magnesium, sulfate, and manganese were higher during the cool season.Surrogate-regression models developed by using continuous water-quality data showed that the annual sediment load for the 2013 water year was about 2,600 tons, with more than 90 percent of this sediment contributed during two storms. The total phosphorus load in 2013 was about 13,000 pounds with more than 90 percent contributed during the same two storms as sediment. The load of total nitrogen, 140,000 pounds, accumulated steadily throughout the 2013 water year as nitrate in groundwater continuously discharged into the stream. The same two large storms that contributed 90 percent of the suspended-sediment and total phosphorus load only contributed about 20 percent of the annual total nitrogen load.Extensive water-quality monitoring of stream base flow throughout the Upper Chester River watershed identified how differences in land use and hydrogeology affected water chemistry. In parts of the watershed with well-drained soil and thick sandy aquifer sediments, concentrations of nitrate and other chemicals associated with fertilizer and lime application increased in streams as agricultural land use increased. More than 90 percent of the nitrogen in streams from these areas was in the form of nitrate, and concentrations ranged from about 5 milligrams per liter (mg/L) to 8 mg/L as nitrogen in the two largest tributaries. Stream nitrate concentrations were about 1 mg/L as nitrogen where soils were more poorly drained, the surficial aquifer sediments were thinner, and forests and wetlands were more widespread than agriculture. Nitrate isotope data were consistent with inorganic fertilizers ± atmospheric deposition and N2 fixation as sources of nitrogen, and with nitrification as the dominant nitrate-forming process. Nitrate reduction was indicated by elevated δ15N and δ18O values in some samples from streams draining watersheds with poorly drained soils. An analysis of land-use data and SPARROW modeling input data attributed almost 90 percent of the nitrogen sources in the Upper Chester River watershed to inorganic fertilizer and fixation of atmospheric nitrogen by legumes, which is in agreement with the isotopic characteristics of nitrate in this watershed. Local sources of manure are limited in this area. Total phosphorus concentrations during base flow ranged from below detection to about 0.2 mg/L. Stream phosphorus concentrations during base flow were generally lower than those measured during storms because most phosphorus transport likely occurs as phosphorus attached to sediment particles during runoff. Because manure is not widely used in this area, the major source of phosphorus is likely fertilizer.The implementation of conservation practices in the Upper Chester River watershed increased substantially during the study period, with a total implementation of 1,194 U.S. Department of Agriculture-compliant practices. The most frequently used practices were oriented towards nutrient and sediment control, including cover crops, nutrient management planning, conservation crop rotation, conservation tillage, and irrigation management. The current Chesapeake Bay model for this area predicts that implementation of best management practices should result in a 13-percent decrease in overall delivery of nitrogen to the Upper Chester River. Because most nitrogen travels through the groundwater system for years to decades before being discharged to streams, the time period of monitoring was not sufficient to see the effects of these practices on water quality. The magnitude of the effect that may eventually be detected will depend on the degree to which nitrate leaching into the groundwater system is reduced over time. Loadings of phosphorus and sediment are primarily transported during large runoff events and are difficult to control and analyze for trends because of their timing and episodic nature.Conewago CreekConewago Creek has two primary monitoring locations—one near the middle of the 47-mi2 watershed and the other near the outlet just upstream of the Susquehanna River. The base-flow index was 47.3 percent for 2012–2013, indicating that on average, approximately 53 percent of the streamflow in Conewago Creek exited the watershed as surface flow, which suggests that the stormwater runoff was somewhat greater than groundwater discharge (base flow). A series of cluster and principal components analyses demonstrated that the majority of the variability in the Conewago Creek water quality could be attributed to hydrologic and seasonal variability. Statistically significant positive correlations with flow were observed at both monitoring sites for ammonium, total phosphorus, orthophosphate, iron, and manganese; additionally, at the upstream monitoring station, total nitrogen demonstrated a statistically significant positive correlation with flow. Statistically significant inverse correlations with flow were observed at both sites for water temperature, specific conductance (at the downstream site only), sulfate, chloride, calcium, and magnesium. Statistically significant seasonal patterns were observed for several water-quality constituents. Water temperature, phosphorus (upstream site only), and orthophosphate were higher during the warm season, and nitrate and total nitrogen (upstream site only) were higher during the cool season.Surrogate regression models were developed to compute sediment and nutrient load in Conewago Creek by using the continuous water-quality monitors and water-quality samples. Conewago Creek sediment load was approximately 9,900 tons in 2012 and approximately 18,900 tons in 2013, with nearly 80 percent of the sediment load in 2013 contributed by the three largest storm events. Annual total nitrogen loads could not be estimated due to poor model performance. The addition of continued monitoring or a continuously recording nitrate sensor could improve estimates of total nitrogen loads. During 2012 and 2013, phosphorus loads in Conewago Creek were approximately 50,000 pounds in each year.Combining data from one high-flow synoptic sampling with the data from routine sampling revealed how the geology and hydrology interact to result in variable water chemistry throughout the Conewago Creek watershed. The areas above the upstream gage in the headwaters are generally underlain by forested non-carbonate bedrock and are characterized by relatively low nitrate, specific conductance, calcium, and magnesium, as well as relatively low concentrations of phosphorus, ammonium, iron, and manganese. The more developed, agricultural areas below the upstream site were generally characterized by higher ionic strength waters with higher nutrient and metal concentrations. An analysis of land-use data and SPAtially Referenced Regressions On Watershed (SPARROW) modeling data indicates that manure sources of nitrogen dominate the input of nitrogen to the watershed.Implementation of conservation practices increased in the Conewago Creek watershed during the study period, and while a broad range of practice types were implemented, the most common practices included residue and tillage management, cover crops, nutrient management, terracing, and stream fencing (for animal exclusion or bank restoration). While the implementation of these conservation practices is encouraging, the cumulative effects of these practices probably will not be detected in Conewago Creek water quality for several years. The magnitude of the effects of these conservation practices on water quality in Conewago Creek will depend largely on the extent to which nutrient loading (septic, manure, and commercial fertilizer) and sediment-producing activities are reduced over time.Difficult RunThe Difficult Run watershed is a 57.82-mi2 watershed that drains to the Potomac River. The long-term Difficult Run base-flow index (from 1936 to 2010) was 57.9, indicating that approximately 58 percent of streamflow exited the watershed as base flow and 42 percent as stormflow; however, with continued development and urbanization of the watershed, the base-flow index has decreased to 50 percent during the last 20 years. This base-flow index was less than those of the other watersheds evaluated in this study, likely because the Difficult Run watershed largely is underlain by crystalline piedmont metamorphic rocks and has a greater proportion of impervious urban land cover. A series of cluster and principal components analyses indicated that most of the variability in Difficult Run water quality could be attributed to hydrologic variability and seasonality. Statistically significant positive correlations with flow were observed for turbidity, dissolved oxygen, suspended sediments, ammonium, orthophosphate, iron, and total phosphorus. Statistically significant inverse correlations with flow were observed for water temperature, pH, specific conductance, bicarbonate, calcium, magnesium, nitrate, δ15N of nitrate, and silica. Statistically significant seasonal patterns were observed for numerous water-quality constituents: water temperature, ammonium, orthophosphate, and δ15N of nitrate were higher during the warm season, and dissolved oxygen, nitrate, and manganese were higher during the cool season. Surrogate regression models were developed to compute sediment and nutrient loading rates. The Difficult Run sediment load was approximately 8,000 tons per year, with greater than 95 percent of the sediment load in the 2013 water year contributed by the seven largest storm events. The total phosphorus load in Difficult Run was approximately 14,000 pounds of phosphorus per year, with the majority of the load contributed during stormflow periods. The total nitrogen load in Difficult Run is estimated to have been approximately 140,000 pounds per year, with total nitrogen accumulation less dominated by stormflow contributions than that of phosphorus and strongly affected by base-flow export of nitrogen from the basin.Extensive water-quality monitoring throughout the Difficult Run watershed revealed relatively uniform generation of flow per unit of watershed area, as well as spatial variation in water quality that is strongly related to land-use activities. Elevated nitrate concentrations were observed in a subset of monitoring sites that are inversely correlated with population density and positively correlated to the septic system density within each subwatershed. The majority of the elevated nitrate concentrations for these sites are hypothesized to be caused by nitrate leaching from septic systems, more so than homeowner fertilizer usage among these subwatersheds that have lower population densities than other parts of the watershed. Nitrate isotope data, temporal patterns in the water-quality data, mass-balance computations, and a separate land-use analysis all generally indicate that leachate from septic systems was the likely source of the elevated nitrate. Another group of water-quality sites have relatively low nitrogen concentrations, are located in areas that are served by city sewer lines, and have experienced stream restoration activities. A final group of sites drained the areas with the highest imperviousness and had strongly elevated specific conductance, chloride, and sodium, which were likely caused by a combination of road salting and other anthropogenic sources draining these urbanized areas in the watershed. A fourth group of sites represents a mixture of water sources and had water quality similar to that at the Difficult Run streamgage. Analysis of the nitrate isotope data generally indicates a broad range of composition indicative of mixed natural and anthropogenic nitrogen sources. Implementation of conservation practices increased in the Difficult Run watershed during the study period, and while a broad range of practice types was implemented, the most common practices included stream restoration. While the implementation of these conservation practices is encouraging, the cumulative effect of these practices probably will not be detected in Difficult Run water quality for several years.

Specific Roles for 17ß-Estradiol versus Gonad Development in Nutrient Partitioning and Regulation of Nutrient- and Growth-Related Mechanisms During Sexual Maturation in Rainbow Trout

USDA-ARS?s Scientific Manuscript database

The contribution of sex steroids to nutrient partitioning and energy balance during gonad development was studied in rainbow trout (Oncorhynchus mykiss). Nineteen month old triploid (3N) female rainbow trout were fed a diet supplemented with 17ß-estradiol (E2) at 30 mg steroid/kg diet for a 1 month...

Dietary sources of energy and nutrients in the contemporary diet of Inuit adults: results from the 2007-08 Inuit Health Survey.

PubMed

Kenny, Tiff-Annie; Hu, Xue Feng; Kuhnlein, Harriet V; Wesche, Sonia D; Chan, Hing Man

2018-05-01

To characterize the major components of the contemporary Inuit diet and identify the primary sources of energy and essential nutrients. Dietary data were derived from the 24 h recall collected by the Inuit Health Survey (IHS) from 2007 to 2008. The population proportion method was used to determine the percentage contribution of each group. Unique food items/preparations (ninety-three country foods and 1591 market foods) were classified into eight country food groups and forty-one market food groups. Nutrient composition of each food item was obtained from the Canadian Nutrient File. Thirty-six communities across three Inuit regions of northern Canada. A representative sample (n 2095) of non-pregnant Inuit adults (≥18 years), selected through stratified random sampling. Despite their modest contribution to total energy intake (6·4-19·6 %, by region) country foods represented a major source of protein (23-52 %), Fe (28-54 %), niacin (24-52 %) and vitamins D (up to 73 %), B6 (18-55 %) and B12 (50-82 %). By contrast, the three most popular energy-yielding market foods (i.e. sweetened beverages, added sugar and bread) collectively contributed approximately 20 % of total energy, while contributing minimally to most micronutrients. A notable exception was the contribution of these foods to Ca (13-21 %) and vitamins E (17-35 %) and C (as much as 50 %). Solid fruits were consumed by less than 25 % of participants while vegetables were reported by 38-59 % of respondents. Country foods remain a critical dimension of the contemporary Inuit diet.

Involvement of Small RNAs in Phosphorus and Sulfur Sensing, Signaling and Stress: Current Update

PubMed Central

Kumar, Smita; Verma, Saurabh; Trivedi, Prabodh K.

2017-01-01

Plants require several essential mineral nutrients for their growth and development. These nutrients are required to maintain physiological processes and structural integrity in plants. The root architecture has evolved to absorb nutrients from soil and transport them to other parts of the plant. Nutrient deficiency affects several physiological and biological processes in plants and leads to reduction in crop productivity and yield. To compensate this adversity, plants have developed adaptive mechanisms to enhance the acquisition, conservation, and mobilization of these nutrients under deficient or adverse conditions. In addition, plants have evolved an intricate nexus of complex signaling cascades, which help in nutrient sensing and uptake as well as to maintain nutrient homeostasis. In recent years, small non-coding RNAs such as micro RNAs (miRNAs) and endogenous small interfering RNAs have emerged as important component in regulating plant stress responses. A set of these small RNAs (sRNAs) have been implicated in regulating various processes involved in nutrient uptake, assimilation, and deficiency. In response to phosphorus (P) and sulphur (S) deficiencies, role of sRNAs, miR395 and miR399, have been identified to be instrumental; however, many more miRNAs might be involved in regulating the plant response to these nutrient stresses. These sRNAs modulate expression of target genes in response to P and S deficiencies and regulate their uptake and utilization for proper growth and development of the plant. This review summarizes the current understanding of uptake, sensing, and signaling of P and S and highlights the regulatory role of sRNAs in adaptive responses to these nutrient stresses in plants. PMID:28344582

Carbon and nutrients recycling when leaves falling off: mycorrhizal association matters

NASA Astrophysics Data System (ADS)

Zhang, H., II; Lü, X. T.; Hartmann, H.; Han, X.; Trumbore, S.

2016-12-01

Root-associated mycorrhizal fungi is being increasingly recognized for their roles in influencing soil carbon (C) storage, plant growth and nutrient cycling, whereas mycorrhizae-mediated C dynamics and nutrient acquisition strategy strongly different. Because of a reinforcing feedback from belowground, how different mycorrhizal plants differ in aboveground nutrient status and recycle from senesced to green leaves remains unknown. Based on a global database of C and nutrients concentrations in plant green and senesced leaves, we further identified plant mycorrhizal types (here focus on arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) plants) for woody species and tested whether mycorrhizal types showing consistent effects in plant nutrient status and recycle. Generally, nutrient resorptions from senesced to green leaves for ECM plants are more conservative, balanced and sensitive to climate compare to AM plants. Specifically, we first found lower nutrients concentrations in green and senesced leaves whereas greater nutrient resorption efficiency (NuR) for ECM vs. AM plants. However, C concentration in green and senesced leaves were significant greater while NuR was lower for ECM plants. Second, compare to that for AM plants, we found a general balanced N:P resorption ratio ( 1) for ECM plants, indicating ECM plants had greater ability to balance their N and P resorption simultaneously. Third, we found NuR in N, P and K (potassium) for ECM plants were sensitive to the variation of MAT and MAP while these for AM plants showed no clear trend. Our results suggested that accounting for the influence of mycorrhizae on C and nutrient dynamics in vegetation models will be critical for predicting ecosystem responses and feedbacks to climate change.

'Trophic whales' as biotic buffers: weak interactions stabilize ecosystems against nutrient enrichment.

PubMed

Schwarzmüller, Florian; Eisenhauer, Nico; Brose, Ulrich

2015-05-01

Human activities may compromise biodiversity if external stressors such as nutrient enrichment endanger overall network stability by inducing unstable dynamics. However, some ecosystems maintain relatively high diversity levels despite experiencing continuing disturbances. This indicates that some intrinsic properties prevent unstable dynamics and resulting extinctions. Identifying these 'ecosystem buffers' is crucial for our understanding of the stability of ecosystems and an important tool for environmental and conservation biologists. In this vein, weak interactions have been suggested as stabilizing elements of complex systems, but their relevance has rarely been tested experimentally. Here, using network and allometric theory, we present a novel concept for a priori identification of species that buffer against externally induced instability of increased population oscillations via weak interactions. We tested our model in a microcosm experiment using a soil food-web motif. Our results show that large-bodied species feeding at the food web's base, so called 'trophic whales', can buffer ecosystems against unstable dynamics induced by nutrient enrichment. Similar to the functionality of chemical or mechanical buffers, they serve as 'biotic buffers' that take up stressor effects and thus protect fragile systems from instability. We discuss trophic whales as common functional building blocks across ecosystems. Considering increasing stressor effects under anthropogenic global change, conservation of these network-intrinsic biotic buffers may help maintain the stability and diversity of natural ecosystems. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Novel/non-conventional manure application practices to minimize environmental impacts

USDA-ARS?s Scientific Manuscript database

Livestock manure can supply essential crop nutrients and contribute to improved soil quality. However, conventional surface broadcast application can result in adverse environmental effects from NH3 volatilization, odor, and runoff losses of nutrients and pathogens. Incorporation of manure by tillag...

THE ASSOCIATION OF LAND USE/LAND COVER AND NUTRIENT LEVELS IN MARYLAND STREAMS

EPA Science Inventory

Anthropogenic nonpoint sources of nutrients are known to cause accelerated eutrophication of estuaries. The Chesapeake Bay is one of the world's largest estuaries exhibiting the eutrophication problem caused by pollution from various land use activities. The sources contributing ...

Fungicide and Nutrient Transport with Runoff from Creeping Bentgrass Turf

USDA-ARS?s Scientific Manuscript database

The detection of pesticides and excess nutrients in surface waters of urban watersheds has lead to increased environmental concern and suspect of contaminant contributions from residential, urban, and recreational sources. Highly managed biotic systems such as golf courses and commercial landscapes ...

Groundwater-derived nutrient and trace element transport to a nearshore Kona coral ecosystem: Experimental mixing model results

USGS Publications Warehouse

Prouty, Nancy G.; Swarzenski, Peter W.; Fackrell, Joseph; Johannesson, Karen H.; Palmore, C. Diane

2017-01-01

Study regionThe groundwater influenced coastal waters along the arid Kona coast of the Big Island, Hawai’i.Study focusA salinity-and phase partitioning-based mixing experiment was constructed using contrasting groundwater endmembers along the arid Konacoast of the Big Island, Hawai’i and local open seawater to better understand biogeochemical and physicochemical processes that influence the fate of submarine groundwater discharge (SGD)-derived nutrients and trace elements.New Hydrological Insights for the RegionTreated wastewater effluent was the main source for nutrient enrichment downstream at the Honokōhau Harbor site. Conservative mixing for some constituents, such as nitrate + nitrite, illustrate the effectiveness of physical mixing to maintain oceanic concentrations in the colloid (0.02–0.45 μm) and truly dissolved (

Consumer species richness and nutrients interact in determining producer diversity.

PubMed

Groendahl, Sophie; Fink, Patrick

2017-03-17

While it is crucial to understand the factors that determine the biodiversity of primary producer communities, the relative importance of bottom-up and top-down control factors is still poorly understood. Using freshwater benthic algal communities in the laboratory as a model system, we find an unimodal relationship between nutrient availability and producer diversity, and that increasing number of consumer species increases producer diversity, but overall grazing decreases algal biodiversity. Interestingly, these two factors interact strongly in determining producer diversity, as an increase in nutrient supply diminishes the positive effect of consumer species richness on producer biodiversity. This novel and thus-far overlooked interaction of bottom-up and top-down control mechanisms of biodiversity may have a pronounced impact on ecosystem functioning and thus have repercussions for the fields of biodiversity conservation and restoration.

Consumer species richness and nutrients interact in determining producer diversity

PubMed Central

Groendahl, Sophie; Fink, Patrick

2017-01-01

While it is crucial to understand the factors that determine the biodiversity of primary producer communities, the relative importance of bottom-up and top-down control factors is still poorly understood. Using freshwater benthic algal communities in the laboratory as a model system, we find an unimodal relationship between nutrient availability and producer diversity, and that increasing number of consumer species increases producer diversity, but overall grazing decreases algal biodiversity. Interestingly, these two factors interact strongly in determining producer diversity, as an increase in nutrient supply diminishes the positive effect of consumer species richness on producer biodiversity. This novel and thus-far overlooked interaction of bottom-up and top-down control mechanisms of biodiversity may have a pronounced impact on ecosystem functioning and thus have repercussions for the fields of biodiversity conservation and restoration. PMID:28303953

Subterranean Groundwater Nutrient Input to Coastal Oceans and Coral Reef Sustainability

NASA Astrophysics Data System (ADS)

Paytan, A.; Street, J. H.

2003-12-01

Coral reefs are often referred to as the tropical rain forests of the oceans because of their high productivity and biodiversity. Recent observations in coral reefs worldwide have shown clear degradation in water quality and coral reef health and diversity. The implications of this are severe, including tremendous economic losses mostly though fishing and tourism. Nutrient loading has been implicated as one possible cause for the ecosystem decline. A previously unappreciated potential source of nutrient loading is submarine ground water discharge (SGW). Ground water in many cases has high nutrient content from sewage pollution and fertilizer application for agriculture and landscaping. To better understand the effect of this potential source of nutrient input and degrading water quality, we are exploring the contribution of SGW to the nutrient levels in coral reefs. A key to this approach is determining the amount and source of SGW that flows into the coast as well as its nutrient concentrations. The SGW flux and associated input of chemical dissolved load (nutrient, DOC, trace elements and other contaminants) is quantified using naturally occurring Ra isotopes. Radium isotopes have been shown to be excellent tracers for SGW inputs into estuaries and coastal areas (Moore, 1996; Hussain et al., 1999; Kerst et al., 2000). Measurements of Ra activity within the coral reef, the lagoons and the open waters adjacent to the reef provide valuable information regarding the input of Ra as well as nutrients and possibly pollutant from groundwater discharge. Through this analysis the effect of SGD on the delicate carbon and nutrient balance of the fragile coral reef ecosystem could be evaluated. In addition to quantifying the contribution of freshwater to the nutrient mass balance in the reef, information regarding the length of time a water parcel has remained in the near-shore region over the reef can be estimated using the Ra isotope quartet.

Use of point-of-sale data to assess food and nutrient quality in remote stores.

PubMed

Brimblecombe, Julie; Liddle, Robyn; O'Dea, Kerin

2013-07-01

To examine the feasibility of using point-of-sale data to assess dietary quality of food sales in remote stores. A multi-site cross-sectional assessment of food and nutrient composition of food sales. Point-of-sale data were linked to Australian Food and Nutrient Data and compared across study sites and with nutrient requirements. Remote Aboriginal Australia. Six stores. Point-of-sale data were readily available and provided a low-cost, efficient and objective assessment of food and nutrient sales. Similar patterns in macronutrient distribution, food expenditure and key food sources of nutrients were observed across stores. In all stores, beverages, cereal and cereal products, and meat and meat products comprised approximately half of food sales (range 49–57 %). Fruit and vegetable sales comprised 10.4 (SD 1.9) % on average. Carbohydrate contributed 54.4 (SD 3.0) % to energy; protein 13.5 (SD 1.1) %; total sugars 28.9 (SD 4.3) %; and the contribution of total saturated fat to energy ranged from 11.0 to 14.4% across stores. Mg, Ca, K and fibre were limiting nutrients, and Na was four to five times higher than the midpoint of the average intake range. Relatively few foods were major sources of nutrients. Point-of-sale data enabled an assessment of dietary quality within stores and across stores with no burden on communities and at no cost, other than time required for analysis and reporting. Similar food spending patterns and nutrient profiles were observed across the six stores. This suggests potential in using point-of-sale data to monitor and evaluate dietary quality in remote Australian communities.

External nutrient loading from land, sea and atmosphere to all 656 Swedish coastal water bodies.

PubMed

Bryhn, Andreas C; Dimberg, Peter H; Bergström, Lena; Fredriksson, Ronny E; Mattila, Johanna; Bergström, Ulf

2017-01-30

Identifying the main sources of nutrient loading is a key factor for efficient mitigation of eutrophication. This study has investigated the pathways of external nutrient loading to 656 coastal water bodies along the entire Swedish coastline. The studied water bodies have been delineated to meet requirements in the European Union's Water Framework Directive, and recent status assessments have shown that 57% of them fail to attain good or high ecological status with respect to nutrients. The analysis in the study was performed on data from mass-balance based nutrient budgets computed using the modelling framework Vattenwebb. The external nutrient contribution from the sea to the water bodies was highly variable, ranging from about 1% to nearly 100%, but the median contribution was >99% of the total external loading regarding both nitrogen and phosphorus. External loading from the atmosphere and local catchment area played a minor role in general. However, 45 coastal water bodies received >25% of the external nitrogen and phosphorus from their catchments. Loading from land typically peaked in April following ice-break and snow melting and was comparatively low during summer. The results indicate that for many eutrophicated Swedish coastal water bodies, nutrient abatement is likely to be optimally effective when potential measures in all of the catchment area of the concerned sea basin are considered. Local-scale mitigation in single water bodies will likely be locally effective only in the small proportion of areas where water and thereby also nutrient input from the catchment is high compared to the influx from the sea. Future studies should include nutrient reduction scenarios in order to refine these conclusions and to identify relevant spatial scales for coastal eutrophication mitigation measures from a water body perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

78 FR 60918 - Notice of Permit Applications Received Under the Antarctic Conservation Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-02

... commercially available, bacteria supplement for municipal Wastewater Treatment Plants, to be used in the... enzymatic substrate, nutrient base and bacteria for the treatment process. Bacteria would not be released to the marine environment. Most of the bacteria are eventually captured in the wastewater treatment plant...

A decade of evaluating the ecological effects of grass filter strips on channelized agricultural headwater streams

USDA-ARS?s Scientific Manuscript database

Grass filter strips are a widely used conservation practice in the Midwestern United States for reducing nutrient, pesticide, and sediment inputs into agricultural streams. Previous studies have documented the effectiveness of grass filter strips in reducing the input of agricultural pollutants, bu...

The Utilization of Edge-of-Field Monitoring of Agricultural Runoff in Addressing Nonpoint Source Pollution

USDA-ARS?s Scientific Manuscript database

While basin-scale studies and modeling are important tools in relating land uses to water quality concerns, edge-of-field monitoring (EOFM) provides the necessary resolution to spatially target, design, and evaluate in-field conservation practices for reducing nutrient and sediment loading from agri...

Farm-system modeling to evaluate environmental losses, profitability, and best management practice cost-effectiveness

USDA-ARS?s Scientific Manuscript database

To meet Chesapeake Bay Total Maximum Daily Load requirements for agricultural pollution, conservation districts and farmers are tasked with implementing best management practices (BMPs) that reduce farm losses of nutrients and sediment. The importance of the agricultural industry to the regional eco...

Assessment of benefits of conservation agriculture on soil functions in arable production systems in Europe

USDA-ARS?s Scientific Manuscript database

Conventional tillage (CT), with reduced alternatives in crop rotation (monocropping), is the norm in European farming. CT may cause adverse effects on some of the five major soil functions, viz. primary productivity, carbon sequestration and regulation, nutrient cycling and provision, water regulati...

Soils under conservation agriculture with vegetables in Siem Reap, Cambodia

USDA-ARS?s Scientific Manuscript database

Smallholder vegetable farmers in Siem Reap, Cambodia experienced declining crop productivity. It could be a result of a mixture of factors such as nutrient and pest problems and extreme weather events such as droughts and/or heavy rains. The no-till, continuous mulch and diverse species principles o...

Headwater fish population responses to planting grass filter strips adjacent to channelized agricultural headwater streams

USDA-ARS?s Scientific Manuscript database

Grass filter strips are a widely used conservation practice in the Midwestern United States for reducing nutrient, pesticide, and sediment inputs into agricultural streams. Only a limited amount of information is available on the ecological effects of planting grass filter strips adjacent to channe...

Competition from below for light and nutrients shifts productivity among tropical species

Treesearch

J. J. Ewel; M. J. Mazzarino

2008-01-01

Chance events such as seed dispersal determine the potential composition of plant communities, but the eventual assemblage is determined in large part by subsequent interactions among species. Postcolonization sorting also affects the ultimate composition of communities assembled by people for restoration, horticulture, or conservation. Thus,...

Hydrologic transport of fecal bacteria attenuated by flu gas desulfurized (FGD) gypsum

USDA-ARS?s Scientific Manuscript database

Background Flue gas desulfurized (FGD) gypsum is a byproduct of coal-fired power plants. As a soil amendment for crop production it has the potential of improving soil water infiltration, soil conservation, and decreasing nutrient losses from broiler litter applications. Because broiler litter is a ...

Endangered Right Whales Enhance Primary Productivity in the Bay of Fundy

PubMed Central

Roman, Joe; Nevins, John; Altabet, Mark; Koopman, Heather; McCarthy, James

2016-01-01

Marine mammals have recently been documented as important facilitators of rapid and efficient nutrient recycling in coastal and offshore waters. Whales enhance phytoplankton nutrition by releasing fecal plumes near the surface after feeding and by migrating from highly productive, high-latitude feeding areas to low-latitude nutrient-poor calving areas. In this study, we measured NH4+ and PO43- release rates from the feces of North Atlantic right whales (Eubalaena glacialis), a highly endangered baleen whale. Samples for this species were primarily collected by locating aggregations of whales in surface-active groups (SAGs), which typically consist of a central female surrounded by males competing for sexual activity. When freshly collected feces were incubated in seawater, high initial rates of N release were generally observed, which decreased to near zero within 24 hours of sampling, a pattern that is consistent with the active role of gut microflora on fecal particles. We estimate that at least 10% of particulate N in whale feces becomes available as NH4+ within 24 hours of defecation. Phosphorous was also abundant in fecal samples: initial release rates of PO43- were higher than for NH4+, yielding low N/P nutrient ratios over the course of our experiments. The rate of PO43- release was thus more than sufficient to preclude the possibility that nitrogenous nutrients supplied by whales would lead to phytoplankton production limited by P availability. Phytoplankton growth experiments indicated that NH4+ released from whale feces enhance productivity, as would be expected, with no evidence that fecal metabolites suppress growth. Although North Atlantic right whales are currently rare (approximately 450 individuals), they once numbered about 14,000 and likely played a substantial role in recycling nutrients in areas where they gathered to feed and mate. Even though the NH4+ released from fresh whale fecal material is a small fraction of total whale fecal nitrogen, and recognizing the fact that the additional nitrogen released in whale urine would be difficult to measure in a field study, the results of this study support the idea that the distinctive isotopic signature of the released NH4+ could be used to provide a conservative estimate of the contribution of the whale pump to primary productivity in coastal regions where whales congregate. PMID:27331902

Endangered Right Whales Enhance Primary Productivity in the Bay of Fundy.

PubMed

Roman, Joe; Nevins, John; Altabet, Mark; Koopman, Heather; McCarthy, James

2016-01-01

Marine mammals have recently been documented as important facilitators of rapid and efficient nutrient recycling in coastal and offshore waters. Whales enhance phytoplankton nutrition by releasing fecal plumes near the surface after feeding and by migrating from highly productive, high-latitude feeding areas to low-latitude nutrient-poor calving areas. In this study, we measured NH4+ and PO43- release rates from the feces of North Atlantic right whales (Eubalaena glacialis), a highly endangered baleen whale. Samples for this species were primarily collected by locating aggregations of whales in surface-active groups (SAGs), which typically consist of a central female surrounded by males competing for sexual activity. When freshly collected feces were incubated in seawater, high initial rates of N release were generally observed, which decreased to near zero within 24 hours of sampling, a pattern that is consistent with the active role of gut microflora on fecal particles. We estimate that at least 10% of particulate N in whale feces becomes available as NH4+ within 24 hours of defecation. Phosphorous was also abundant in fecal samples: initial release rates of PO43- were higher than for NH4+, yielding low N/P nutrient ratios over the course of our experiments. The rate of PO43- release was thus more than sufficient to preclude the possibility that nitrogenous nutrients supplied by whales would lead to phytoplankton production limited by P availability. Phytoplankton growth experiments indicated that NH4+ released from whale feces enhance productivity, as would be expected, with no evidence that fecal metabolites suppress growth. Although North Atlantic right whales are currently rare (approximately 450 individuals), they once numbered about 14,000 and likely played a substantial role in recycling nutrients in areas where they gathered to feed and mate. Even though the NH4+ released from fresh whale fecal material is a small fraction of total whale fecal nitrogen, and recognizing the fact that the additional nitrogen released in whale urine would be difficult to measure in a field study, the results of this study support the idea that the distinctive isotopic signature of the released NH4+ could be used to provide a conservative estimate of the contribution of the whale pump to primary productivity in coastal regions where whales congregate.

Mainstreaming the social sciences in conservation.

PubMed

Bennett, Nathan J; Roth, Robin; Klain, Sarah C; Chan, Kai M A; Clark, Douglas A; Cullman, Georgina; Epstein, Graham; Nelson, Michael Paul; Stedman, Richard; Teel, Tara L; Thomas, Rebecca E W; Wyborn, Carina; Curran, Deborah; Greenberg, Alison; Sandlos, John; Veríssimo, Diogo

2017-02-01

Despite broad recognition of the value of social sciences and increasingly vocal calls for better engagement with the human element of conservation, the conservation social sciences remain misunderstood and underutilized in practice. The conservation social sciences can provide unique and important contributions to society's understanding of the relationships between humans and nature and to improving conservation practice and outcomes. There are 4 barriers-ideological, institutional, knowledge, and capacity-to meaningful integration of the social sciences into conservation. We provide practical guidance on overcoming these barriers to mainstream the social sciences in conservation science, practice, and policy. Broadly, we recommend fostering knowledge on the scope and contributions of the social sciences to conservation, including social scientists from the inception of interdisciplinary research projects, incorporating social science research and insights during all stages of conservation planning and implementation, building social science capacity at all scales in conservation organizations and agencies, and promoting engagement with the social sciences in and through global conservation policy-influencing organizations. Conservation social scientists, too, need to be willing to engage with natural science knowledge and to communicate insights and recommendations clearly. We urge the conservation community to move beyond superficial engagement with the conservation social sciences. A more inclusive and integrative conservation science-one that includes the natural and social sciences-will enable more ecologically effective and socially just conservation. Better collaboration among social scientists, natural scientists, practitioners, and policy makers will facilitate a renewed and more robust conservation. Mainstreaming the conservation social sciences will facilitate the uptake of the full range of insights and contributions from these fields into conservation policy and practice. © 2016 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.

Spatial patterns of soil nutrients and groundwater levels within the Debre Mawi watershed of the Ethiopian highlands

NASA Astrophysics Data System (ADS)

Guzman, Christian; Tilahun, Seifu; Dagnew, Dessalegn; Zegeye, Assefe; Tebebu, Tigist; Yitaferu, Birru; Steenhuis, Tammo

2015-04-01

Persistent patterns of erosion have emerged in the Ethiopian highlands leading to soil and water conservation practices being implemented throughout the countryside. A common concern is the loss of soil fertility and loss of soil water. This study investigates the spatial patterns of soil nutrients and water table depths in a small sub-watershed in the northwestern Ethiopian highlands. NPK, a particularly important group of nutrients for inorganic fertilizer considerations, did not follow a consistent trend as a group along and across slope and land use transects. Whereas nitrogen content was greatest in the upslope regions (~0.1% TN), available phosphorus had comparably similar content in the different slope regions throughout the watershed (~2.7 mg/kg). The exchangeable cations (K, Ca, Mg) did increase in content in a downslope direction (in most cases though, they were highest in the middle region) but not consistently later in the season. On average, calcium (40 cmol/kg), magnesium (5 cmol/kg), and potassium (0.5 cmol/kg) were orders of magnitudes different in content. The perched water table in different areas of the watershed showed a very distinct trend. The lower part of the sub-watershed had shallower levels of water table depths (less than 10 cm from the surface) than did the upper parts of the sub-watershed (usually greater than 120 cm from the surface). The middle part of the sub-watershed had water table depths located at 40 to 70 cm below the surface. These results show how the landscape slope position and land use may be important for planning where and when soil nutrients and water would be expected to be appropriately "conserved" or stored.

Hygienisation and Nutrient Conservation of Sewage Sludge or Cattle Manure by Lactic Acid Fermentation

PubMed Central

Scheinemann, Hendrik A.; Dittmar, Katja; Stöckel, Frank S.; Müller, Hermann; Krüger, Monika E.

2015-01-01

Manure from animal farms and sewage sludge contain pathogens and opportunistic organisms in various concentrations depending on the health of the herds and human sources. Other than for the presence of pathogens, these waste substances are excellent nutrient sources and constitute a preferred organic fertilizer. However, because of the pathogens, the risks of infection of animals or humans increase with the indiscriminate use of manure, especially liquid manure or sludge, for agriculture. This potential problem can increase with the global connectedness of animal herds fed imported feed grown on fields fertilized with local manures. This paper describes a simple, easy-to-use, low-tech hygienization method which conserves nutrients and does not require large investments in infrastructure. The proposed method uses the microbiotic shift during mesophilic fermentation of cow manure or sewage sludge during which gram-negative bacteria, enterococci and yeasts were inactivated below the detection limit of 3 log10 cfu/g while lactobacilli increased up to a thousand fold. Pathogens like Salmonella, Listeria monocytogenes, Staphylococcus aureus, E. coli EHEC O:157 and vegetative Clostridium perfringens were inactivated within 3 days of fermentation. In addition, ECBO-viruses and eggs of Ascaris suum were inactivated within 7 and 56 days, respectively. Compared to the mass lost through composting (15–57%), the loss of mass during fermentation (< 2.45%) is very low and provides strong economic and ecological benefits for this process. This method might be an acceptable hygienization method for developed as well as undeveloped countries, and could play a key role in public and animal health while safely closing the nutrient cycle by reducing the necessity of using energy-inefficient inorganic fertilizer for crop production. PMID:25786255

Eutrophication of Buttermilk Bay, a cape cod coastal embayment: Concentrations of nutrients and watershed nutrient budgets

NASA Astrophysics Data System (ADS)

Valiela, Ivan; Costa, Joseph E.

1988-07-01

Nutrient concentrations in Buttermilk Bay, a coastal embayment on the northern end of Buzzards Bay, MA, are higher in the nearshore where salinities are lower. This pattern suggests that freshwater sources may contribute significantly to nutrient inputs into Buttermilk Bay. To evaluate the relative importance of the various sources we estimated inputs of nutrients by each major source into the watershed and into the bay itself. Septic systems contributed about 40% of the nitrogen and phosphorus entering the watershed, with precipitation and fertilizer use adding the remainder. Groundwater transported over 85% of the nitrogen and 75% of the phosphorus entering the bay. Most nutrients entering the watershed failed to reach the bay; uptake by forests, soils, denitrification, and adsorption intercepted two-thirds of the nitrogen and nine-tenths of the phosphorus that entered the watershed. The nutrients that did reach the bay most likely originated from subsoil injections into groundwater by septic tanks, plus some leaching of fertilizers. Buttermilk Bay water has relatively low nutrient concentrations, probably because of uptake of nutrients by macrophytes and because of relatively rapid tidal flushing. Annual budgets of nutrients entering the watershed showed a low nitrogen-to-phosphorus ratio of 6, but passage of nutrients through the watershed raised N/P to 23, probably because of adsorption of PO4 during transit. The N/P ratio of water that leaves the watershed and presumably enters the bay is probably high enough to maintain active growth of nitrogenlimited coastal producers. There is a seasonal shift in N/P in the water column of Buttermilk Bay. N/P exceeded the 16∶1 Redfield ratio during midwinter; the remainder of the year N/P fell below 16∶1. This suggests that annual budgets do not provide sufficiently detailed data with which to interpret nutrient-limitation of producers. Further, some idea of water turnover is also needed to evaluate impact of loading rates. Urbanization of watersheds seems to increase loadings to nearshore environments, and to shift the nutrient loadings delivered to coastal waters to relatively high N-to-P ratios, potentially stimulating growth of nitrogen-limited primary producers.

Small-scale drivers: the importance of nutrient availability and snowmelt timing on performance of the alpine shrub Salix herbacea.

PubMed

Little, Chelsea J; Wheeler, Julia A; Sedlacek, Janosch; Cortés, Andrés J; Rixen, Christian

2016-04-01

Alpine plant communities are predicted to face range shifts and possibly extinctions with climate change. Fine-scale environmental variation such as nutrient availability or snowmelt timing may contribute to the ability of plant species to persist locally; however, variation in nutrient availability in alpine landscapes is largely unmeasured. On three mountains around Davos, Switzerland, we deployed Plant Root Simulator probes around 58 Salix herbacea plants along an elevational and microhabitat gradient to measure nutrient availability during the first 5 weeks of the summer growing season, and used in situ temperature loggers and observational data to determine date of spring snowmelt. We also visited the plants weekly to assess performance, as measured by stem number, fruiting, and herbivory damage. We found a wide snowmelt gradient which determined growing season length, as well as variations of an order of magnitude or more in the accumulation of 12 nutrients between different microhabitats. Higher nutrient availability had negative effects on most shrub performance metrics, for instance decreasing stem number and the proportion of stems producing fruits. High nutrient availability was associated with increased herbivory damage in early-melting microhabitats, but among late-emerging plants this pattern was reversed. We demonstrate that nutrient availability is highly variable in alpine settings, and that it strongly influences performance in an alpine dwarf shrub, sometimes modifying the response of shrubs to snowmelt timing. As the climate warms and human-induced nitrogen deposition continues in the Alps, these factors may contribute to patterns of local plants persistence.

Contribution of Nutrient Diversity and Food Perceptions to Food and Nutrition Security Among Smallholder Farming Households in Western Kenya: A Case Study.

PubMed

Ng'endo, Mary; Bhagwat, Shonil; Keding, Gudrun B

2018-03-01

Sub-Saharan Africa is the only region in the world where hunger is prevalent in over one-third of the population, with smallholder farming households, producers of over 80% of Africa's food, facing both calorie and micronutrient deficiencies. With agricultural systems serving as the main source of all nutrients, little is known about the extent to which agricultural diversity in different seasons can meet macro- and micronutrient needs in rural Africa. Linkages between nutrient diversity and food species were investigated. A case study was conducted in Western Kenya to assess the seasonal nutrient diversity, seasonal nutrient accessibility levels, and food perceptions in 30 smallholder farms, 7 markets, and among 97 focus group discussion participants, respectively. All present food plant and animal species were inventoried and assigned to 1 of the 7 major Food and Agriculture Organization-defined food groups. Based on 2 macronutrients and 5 micronutrients, dendrogram-based nutrient functional diversity metrics were calculated. On-farm and market food species offered all 7 macro- and micronutrients under investigation, regardless of seasonal variation in species numbers. Although there were varying seasonal nutrient accessibility levels in markets, farms were especially effective in readily availing 4 of the 7 nutrients. However, the main food shortage months coincided only with maize shortage, but a diversity of local foods, deemed to be of low cultural and culinary preferences, were available. Nutrition education on the importance of a diversity of local foods in meeting dietary needs, thus stimulating the demand side, can contribute to achieving year-round household food security.

Integrating Spatial Land Use Analysis and Mathematical Material Flow Analysis for Nutrient Management: A Case Study of the Bang Pakong River Basin in Thailand

NASA Astrophysics Data System (ADS)

Kupkanchanakul, Wallapa; Kwonpongsagoon, Suphaphat; Bader, Hans-Peter; Scheidegger, Ruth

2015-05-01

Rivers in developing and emerging countries often lack good water quality. Tools to assess the water quality in rivers, including identification of possible sources of pollution, are therefore of increasing importance. The aim of this study is to apply mathematical material flow and spatial land use analyses to identify and geographically locate the main nitrogen and phosphorus sources and processes in Bang Pakong Basin (BPB). Potential measures to mitigate the nitrogen and phosphorus loads to the water system can then be efficiently evaluated. The combination of these two methods reveals the overall nutrient load as well as local "hot spots." This allows possible mitigation measures to be discussed with regard to their spatial location. This approach goes beyond previous work in which mathematical material flow analysis was shown to be a useful tool to investigate sources of nutrients regardless of their location. The results show that the main sources contributing nutrients to waterways are aquaculture, such as shrimp, tilapia, catfish, and sea bass farming, as well as rice paddies along the main river. Additional sources contributing nutrients to this basin are field crops, livestock, aquaculture, households, and industry. High levels of nutrient inflows come from feeds and fertilizers through aquaculture and rice cultivation. The excess nutrients run into the waterways by direct discharge from aquaculture and runoff processes from rice paddies. Scenario analysis shows that management practices for aquaculture, rice, pig, and poultry farming are key drivers for reducing nutrients in the BPB.

Integrating spatial land use analysis and mathematical material flow analysis for nutrient management: a case study of the Bang Pakong River Basin in Thailand.

PubMed

Kupkanchanakul, Wallapa; Kwonpongsagoon, Suphaphat; Bader, Hans-Peter; Scheidegger, Ruth

2015-05-01

Rivers in developing and emerging countries often lack good water quality. Tools to assess the water quality in rivers, including identification of possible sources of pollution, are therefore of increasing importance. The aim of this study is to apply mathematical material flow and spatial land use analyses to identify and geographically locate the main nitrogen and phosphorus sources and processes in Bang Pakong Basin (BPB). Potential measures to mitigate the nitrogen and phosphorus loads to the water system can then be efficiently evaluated. The combination of these two methods reveals the overall nutrient load as well as local "hot spots." This allows possible mitigation measures to be discussed with regard to their spatial location. This approach goes beyond previous work in which mathematical material flow analysis was shown to be a useful tool to investigate sources of nutrients regardless of their location. The results show that the main sources contributing nutrients to waterways are aquaculture, such as shrimp, tilapia, catfish, and sea bass farming, as well as rice paddies along the main river. Additional sources contributing nutrients to this basin are field crops, livestock, aquaculture, households, and industry. High levels of nutrient inflows come from feeds and fertilizers through aquaculture and rice cultivation. The excess nutrients run into the waterways by direct discharge from aquaculture and runoff processes from rice paddies. Scenario analysis shows that management practices for aquaculture, rice, pig, and poultry farming are key drivers for reducing nutrients in the BPB.

Crop acquisition of phosphorus, iron and zinc from soil in cereal/legume intercropping systems: a critical review

PubMed Central

Xue, Yanfang; Xia, Haiyong; Christie, Peter; Zhang, Zheng; Li, Long; Tang, Caixian

2016-01-01

Background Phosphorus (P), iron (Fe) and zinc (Zn) are essential elements for plant growth and development, but their availability in soil is often limited. Intercropping contributes to increased P, Fe and Zn uptake and thereby increases yield and improves grain nutritional quality and ultimately human health. A better understanding of how intercropping leads to increased plant P, Fe and Zn availability will help to improve P-fertilizer-use efficiency and agronomic Fe and Zn biofortification. Scope This review synthesizes the literature on how intercropping of legumes with cereals increases acquisition of P, Fe and Zn from soil and recapitulates what is known about root-to-shoot nutrient translocation, plant-internal nutrient remobilization and allocation to grains. Conclusions Direct interspecific facilitation in intercropping involves below-ground processes in which cereals increase Fe and Zn bioavailability while companion legumes benefit. This has been demonstrated and verified using isotopic nutrient tracing and molecular analysis. The same methodological approaches and field studies should be used to explore direct interspecific P facilitation. Both niche complementarity and interspecific facilitation contribute to increased P acquisition in intercropping. Niche complementarity may also contribute to increased Fe and Zn acquisition, an aspect poorly understood. Interspecific mobilization and uptake facilitation of sparingly soluble P, Fe and Zn from soil, however, are not the only determinants of the concentrations of P, Fe and Zn in grains. Grain yield and nutrient translocation from roots to shoots further influence the concentrations of these nutrients in grains. PMID:26749590

Application of a Two-Dimensional Reservoir Water-Quality Model of Beaver Lake, Arkansas, for the Evaluation of Simulated Changes in Input Water Quality, 2001-2003

USGS Publications Warehouse

Galloway, Joel M.; Green, W. Reed

2007-01-01

Beaver Lake is considered a primary watershed of concern in the State of Arkansas. As such, information is needed to assess water quality, especially nutrient enrichment, nutrient-algal relations, turbidity, and sediment issues within the system. A previously calibrated two-dimensional, laterally averaged model of hydrodynamics and water quality was used for the evaluation of changes in input nutrient and sediment concentrations on the water quality of the reservoir for the period of April 2001 to April 2003. Nitrogen and phosphorus concentrations were increased and decreased and tested independently and simultaneously to examine the nutrient concentrations and algal response in the reservoir. Suspended-solids concentrations were increased and decreased to identify how solids are distributed in the reservoir, which can contribute to decreased water clarity. The Beaver Lake model also was evaluated using a conservative tracer. A conservative tracer was applied at various locations in the reservoir model to observe the fate and transport and how the reservoir might react to the introduction of a conservative substance, or a worst-case spill scenario. In particular, tracer concentrations were evaluated at the locations of the four public water-supply intakes in Beaver Lake. Nutrient concentrations in Beaver Lake increased proportionally with increases in loads from the three main tributaries. An increase of 10 times the calibrated daily input nitrogen and phosphorus in the three main tributaries resulted in daily mean total nitrogen concentrations in the epilimnion that were nearly 4 times greater than the calibration concentrations at site L2 and more than 2 times greater than the calibrated concentrations at site L5. Increases in daily input nitrogen in the three main tributaries independently did not correspond in substantial increases in concentrations of nitrogen in Beaver Lake. The greatest proportional increase in phosphorus occurred in the epilimnion at sites L3 and L4 and the least increase occurred at sites L2 and L5 when calibrated daily input phosphorus concentrations were increased. When orthophosphorus was increased in all three tributaries simultaneously by a factor of 10, daily mean orthophosphorus concentrations in the epilimnion of the reservoir were almost 11 times greater than the calibrated concentrations at sites L2 and L5, and 15 times greater in the epilimnion of the reservoir at sites L3 and L4. Phosphorus concentrations in Beaver Lake increased less when nitrogen and phosphorus were increased simultaneously than when phosphorus was increased independently. The greatest simulated increase in algal biomass (represented as chlorophyll a) occurred when nitrogen and phosphorus were increased simultaneously in the three main tributaries. On average, the chlorophyll a values only increased less than 1 microgram per liter when concentrations of nitrogen or phosphorous were increased independently by a factor of 10 at all three tributaries. In comparison, when nitrogen and phosphorus were increased simultaneously by a factor of 10 for all three tributaries, the chlorophyll a concentration increased by about 10 micrograms per liter on average, with a maximum increase of about 57 micrograms per liter in the epilimnion at site L3 in Beaver Lake. Changes in algal biomass with changes in input nitrogen and phosphorus were variable through time in the Beaver Lake model from April 2001 to April 2003. When calibrated daily input nitrogen and phosphorus concentrations were increased simultaneously for the three main tributaries, the increase in chlorophyll a concentration was the greatest in late spring and summer of 2002. Changes in calibrated daily input inorganic suspended solids concentrations were examined because of the effect they may have on water clarity in Beaver Lake. The increase in total suspended solids was greatest in the hypolimnion at the upstream end of Beaver Lake, and negligible changes

WATERSHEED NUTRIENT INPUTS, PHYTOPLANKTON ACCUMULATION, AND C STOCKS IN CHESAPEAKE BAY

EPA Science Inventory

Inputs of N and P to Chesapeake Bay have been enhanced by anthropogenic activities. Fertilizers, developed areas, N emissions, and industrial effluents contribute to point and diffuse sources currently 2-20X higher than those from undisturbed watersheds. Enhanced nutrient inputs ...

Turning schedules influence final composition of composted swine manure

USDA-ARS?s Scientific Manuscript database

Liquid swine (Sus scrofa domesticus) manure is a high-moisture, low-nutrient product that limits economical transport to areas in proximity of its source, possibly contributing to localized high soil nutrient levels. Composting swine manure converts liquid slurries to solids at lower moisture conten...

Selenium, Chromium, and Vitamin D: What Dietitians Need to Know Regarding Dietary Supplements

USDA-ARS?s Scientific Manuscript database

Accurate nutrient data for dietary supplement composition are essential for determining supplements’ contribution to total dietary intake. To plan a nationwide adult multivitamin/mineral (MVM) study, the USDA Nutrient Data Laboratory (NDL) obtained prevalence information for the most common labeled...

Stoichiometry of a semi-aquatic plethodontid salamander: Intraspecific variation due to location, size and diet

EPA Science Inventory

Ecological stoichiometry provides a framework to investigate an organism's relationship to nutrient cycles. An organism's stoichiometry is thought to constrain its contribution to nutrient cycles (recycling or storage), and to limit its growth and reproduction. Factors that influ...

Cultural eutrophication control through water reuse.

PubMed

Sala, L; Mujeriego, R

2001-01-01

The increasing use of mineral fertilisers over the last decades has contributed to the appearance of numerous cases of water eutrophication, a new form of water pollution. The starting point of eutrophication is the increase of nutrient concentration (nitrogen and phosphorus) in a water mass, which is subsequently followed by an uncontrolled growth of primary producers and episodes of oxygen depletion due to microbial decomposition of algal organic matter. The excess nutrient loads reaching surface waters are usually associated to discharges from anthropogenic activities, which normally involve direct water usage instead of reuse of reclaimed effluents. Agriculture activities and livestock breeding are two of the main nutrient sources responsible for water eutrophication, as well as human--urban and industrial--wastewater discharges. Wastewater reclamation and reuse can be a suitable strategy for preserving the quality of natural waters, by suppressing effluent discharges and the associated nutrient contributions to receiving waters. Reuse of reclaimed water for agricultural and landscape irrigation as well as for environmental enhancement offers an adequate strategy for preserving natural water systems from eutrophication.

Comparison of Two Spectrophotometric Techniques for Nutrients Analyses in Water Samples

NASA Astrophysics Data System (ADS)

Bartošová, Alica; Michalíková, Anna; Sirotiak, Maroš; Soldán, Maroš

2013-01-01

The aim of this contribution is to compare two common techniques for determining the concentrations of nitrate, nitrite, ammonium and phosphates in surface water and groundwater. Excess of these nutrients in water can directly affect human health (e.g. methemoglobinaemia) or indirectly through the products of secondary pollution - eutrophication (e.g. cyanotoxins, emanation of hydrogen sulphide, mercaptanes, methane...). Negative impact of nutrients excess in surface water often causes the destruction of water ecosystems, and therefore, common substances of these elements must be monitored and managed. For these experiments two spectrophotometric techniques - ultraviolet spectrophotometry and nutrient photometry were used. These techniques are commonly used for quick and simple analyses of nutrients in waste water. There are calibration curves for each nutrient and for determination of their concentration.

Temporal variation in the importance of a dominant consumer to stream nutrient cycling

DOE PAGES

Griffiths, Natalie A.; Hill, Walter

2014-06-19

Animal excretion can be a significant nutrient flux within ecosystems, where it supports primary production and facilitates microbial decomposition of organic matter. The effects of excretory products on nutrient cycling have been documented for various species and ecosystems, but temporal variation in these processes is poorly understood. We examined variation in excretion rates of a dominant grazing snail, Elimia clavaeformis, and its contribution to nutrient cycling, over the course of 14 months in a well-studied, low-nutrient stream (Walker Branch, east Tennessee, USA). Biomass-specific excretion rates of ammonium varied over twofold during the study, coinciding with seasonal changes in food availabilitymore » (measured as gross primary production) and water temperature (multiple linear regression, R 2 = 0.57, P = 0.053). The contribution of ammonium excretion to nutrient cycling varied with seasonal changes in both biological (that is, nutrient uptake rate) and physical (that is, stream flow) variables. On average, ammonium excretion accounted for 58% of stream water ammonium concentrations, 26% of whole-stream nitrogen demand, and 66% of autotrophic nitrogen uptake. Phosphorus excretion by Elimia was contrastingly low throughout the year, supplying only 1% of total dissolved phosphorus concentrations. The high average N:P ratio (89:1) of snail excretion likely exacerbated phosphorus limitation in Walker Branch. To fully characterize animal excretion rates and effects on ecosystem processes, multiple measurements through time are necessary, especially in ecosystems that experience strong seasonality.« less

Temporal variation in the importance of a dominant consumer to stream nutrient cycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffiths, Natalie A.; Hill, Walter

Animal excretion can be a significant nutrient flux within ecosystems, where it supports primary production and facilitates microbial decomposition of organic matter. The effects of excretory products on nutrient cycling have been documented for various species and ecosystems, but temporal variation in these processes is poorly understood. We examined variation in excretion rates of a dominant grazing snail, Elimia clavaeformis, and its contribution to nutrient cycling, over the course of 14 months in a well-studied, low-nutrient stream (Walker Branch, east Tennessee, USA). Biomass-specific excretion rates of ammonium varied over twofold during the study, coinciding with seasonal changes in food availabilitymore » (measured as gross primary production) and water temperature (multiple linear regression, R 2 = 0.57, P = 0.053). The contribution of ammonium excretion to nutrient cycling varied with seasonal changes in both biological (that is, nutrient uptake rate) and physical (that is, stream flow) variables. On average, ammonium excretion accounted for 58% of stream water ammonium concentrations, 26% of whole-stream nitrogen demand, and 66% of autotrophic nitrogen uptake. Phosphorus excretion by Elimia was contrastingly low throughout the year, supplying only 1% of total dissolved phosphorus concentrations. The high average N:P ratio (89:1) of snail excretion likely exacerbated phosphorus limitation in Walker Branch. To fully characterize animal excretion rates and effects on ecosystem processes, multiple measurements through time are necessary, especially in ecosystems that experience strong seasonality.« less

A Comparison of Concentrations of Sodium and Related Nutrients (Potassium, Total Dietary Fiber, Total and Saturated Fat, and Total Sugar) in Private-Label and National Brands of Popular, Sodium-Contributing, Commercially Packaged Foods in the United States.

PubMed

Ahuja, Jaspreet K C; Pehrsson, Pamela R; Cogswell, Mary

2017-05-01

Private-label brands account for about one in four foods sold in US supermarkets. They provide value to consumers due to their low cost. We know of no US studies comparing the nutrition content of private-label products with corresponding national brand products. The objective was to compare concentrations of sodium and related nutrients (potassium, total dietary fiber, total and saturated fat, and total sugar) in popular sodium-contributing, commercially packaged foods by brand type (national or private-label brand). During 2010 to 2014, the Nutrient Data Laboratory of the US Department of Agriculture obtained 1,706 samples of private-label and national brand products from up to 12 locations nationwide and chemically analyzed 937 composites for sodium and related nutrients. The samples came from 61 sodium-contributing, commercially packaged food products for which both private-label and national brands were among the top 75% to 80% of brands for US unit sales. In this post hoc comparative analysis, the authors assigned a variable brand type (national or private label) to each composite and determined mean nutrient contents by brand type overall and by food product and type. The authors tested for significant differences (P<0.05) by brand type using independent sample t tests or Mann-Whitney U tests when appropriate. Overall for all foods sampled, differences between brand types were not statistically significant for any of the nutrients studied. However, differences in both directions exist for a few individual food products and food categories. Concentrations of sodium and related nutrients (potassium, total dietary fiber, total and saturated fat, and total sugar) do not differ systematically between private-label and national brands, suggesting that brand type is not a consideration for nutritional quality of foods in the United States. The study data provide public health officials with baseline nutrient content by brand type to help focus US sodium-reduction efforts. Published by Elsevier Inc.

Nutrition Economics: How to Eat Better for Less.

PubMed

Drewnowski, Adam

2015-01-01

Food prices and diet costs contribute to socioeconomic disparities in diet quality and health. Lower-cost diets provide ample calories but lack essential nutrients. Nutrition economics can remedy health disparities by helping to identify food patterns that are nutrient-rich, affordable, and appealing. First, nutrient profiling models--such as the Nutrient Rich Food (NRF) family of indices--are able to separate foods that are energy-dense from those that are nutrient-rich. Whereas energy-dense foods contain more calories than nutrients, nutrient-rich foods contain more nutrients than calories. Second, new value metrics have identified affordable healthy foods, based on nutrients per unit cost. Third, these methods have now been applied to the analyses of individual foods and beverages, meals, menus, and the total diet. The Healthy Eating Index (HEI), based on compliance with dietary guidelines, was the principal measure of total diet quality. Although healthier diets did generally cost more, some population subgroups managed to obtain nutrient-dense diets at a lower cost. Being able to create affordable, healthy food patterns on limited budgets is an example of nutrition resilience.

Constructed wetlands may lower inorganic nutrient inputs but enhance DOC loadings into a drinking water reservoir in North Wales.

PubMed

Scholz, C; Jones, T G; West, M; Ehbair, A M S; Dunn, C; Freeman, C

2016-09-01

The objective of this study was to monitor a newly constructed wetland (CW) in north Wales, UK, to assess whether it contributes to an improvement in water quality (nutrient removal) of a nearby drinking water reservoir. Inflow and outflow of the Free Water Surface (FWS) CW were monitored on a weekly basis and over a period of 6 months. Physicochemical parameters including pH, conductivity and dissolved oxygen (DO) were measured, as well as nutrients and dissolved organic and inorganic carbon (DOC, DIC) concentration. The CW was seen to contribute to water quality improvement; results show that nutrient removal took place within weeks after construction. It was found that 72 % of initial nitrate (N03 (-)), 53 % of initial phosphate (PO4 (3-)) and 35 % of initial biological oxygen demand (BOD) were removed, calculated as a total over the whole sampling period. From our study, it can be concluded that while inorganic nutrients do decline in CWs, the DOC outputs increases. This may suggest that CWs represent a source for DOC. To assess the carbon in- and output a C budget was calculated.

Framework for characterization. (Revised final report March 1992). Technical pub

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramsay, M.; Boynton, W.; Clark, P.

1992-03-01

The Tampa Bay National Estuary Program (TBNEP) was established in 1990 to develop a comprehensive conservation and management plan, a program to restore and protect Tampa Bay and its resources. The process of identifying the problems of the bay and linking problems to causes is prerequisite to developing the CCMP and is known as characterization. Characterization workshops were held in June and July 1991 to (1) guide the characterization process toward areas of greatest information needs; (2) contribute to the development of a preliminary bay characterization report; and (3) develop a depiction of bay ecosystem components and interrelationships. The workshopsmore » focused on two categories of priority problems: living resources and water quality deterioration. Priority information needs include estuarine seagrasses, low-salinity habitats, and benthic habitats. Refinement of a nitrogen input budget and establishment of cause-effect relationships among nutrient loading dissolved oxygen concentrations and the distribution of seagrass and benthic communities were also identified as priority information needs.« less

Adaptive management for soil ecosystem services

USGS Publications Warehouse

Birge, Hannah E.; Bevans, Rebecca A.; Allen, Craig R.; Angeler, David G.; Baer, Sara G.; Wall, Diana H.

2016-01-01

Ecosystem services provided by soil include regulation of the atmosphere and climate, primary (including agricultural) production, waste processing, decomposition, nutrient conservation, water purification, erosion control, medical resources, pest control, and disease mitigation. The simultaneous production of these multiple services arises from complex interactions among diverse aboveground and belowground communities across multiple scales. When a system is mismanaged, non-linear and persistent losses in ecosystem services can arise. Adaptive management is an approach to management designed to reduce uncertainty as management proceeds. By developing alternative hypotheses, testing these hypotheses and adjusting management in response to outcomes, managers can probe dynamic mechanistic relationships among aboveground and belowground soil system components. In doing so, soil ecosystem services can be preserved and critical ecological thresholds avoided. Here, we present an adaptive management framework designed to reduce uncertainty surrounding the soil system, even when soil ecosystem services production is not the explicit management objective, so that managers can reach their management goals without undermining soil multifunctionality or contributing to an irreversible loss of soil ecosystem services.

Belowground dynamics in mangrove ecosystems

USGS Publications Warehouse

McKee, Karen L.

2004-01-01

Mangrove ecosystems are tropical/subtropical communities of primarily tree species that grow in the intertidal zone. These tidal communities are important coastal ecosystems that are valued for a variety of ecological and societal goods and services (fig. 1). Mangrove wetlands are important filters of materials moving between the land and sea, trapping sediment, nutrients, and pollutants in runoff from uplands and preventing their direct introduction into sensitive marine ecosystems such as seagrass beds and coral reefs. Mangroves serve as nursery grounds and refuge for a variety of organisms and are consequently vital to the biological productivity of coastal waters. Furthermore, because mangroves are highly resilient to disturbances such as hurricanes, they represent a self-sustaining, protective barrier for human populations living in the coastal zone. Mangrove ecosystems also contribute to shoreline stabilization through consolidation of unstable mineral sediments and peat formation. In order to help conserve mangrove ecoystems, scientists with the United States Geological Survey (USGS) at the National Wetlands Research Center are working to more fully understand the dynamics that impact these vital ecosystems.

Enteral feeding: drug/nutrient interaction.

PubMed

Lourenço, R

2001-04-01

Enteral nutrition support via a feeding tube is the first choice for artificial nutrition. Most patients also require simultaneous drug therapy, with the potential risk for drug-nutrient interactions which may become relevant in clinical practice. During enteral nutrition, drug-nutrient interactions are more likely to occur than in patients fed orally. However, there is a lack of awareness about its clinical significance, which should be recognised and prevented in order to optimise nutritional and pharmacological therapeutic goals of safety and efficacy. To raise the awareness of potential drug-nutrient interactions and influence on clinical outcomes. To identify factors that can promote drug-nutrient interactions and contribute to nutrition and/or therapeutic failure. To be aware of different types of drug-nutrient interactions. To understand complex underlying mechanisms responsible for drug-nutrient interactions. To learn basic rules for the administration of medications during tube-feeding. Copyright 2001 Harcourt Publishers Ltd.

Managing urban nutrient biogeochemistry for sustainable urbanization.

PubMed

Lin, Tao; Gibson, Valerie; Cui, Shenghui; Yu, Chang-Ping; Chen, Shaohua; Ye, Zhilong; Zhu, Yong-Guan

2014-09-01

Urban ecosystems are unique in the sense that human activities are the major drivers of biogeochemical processes. Along with the demographic movement into cities, nutrients flow towards the urban zone (nutrient urbanization), causing the degradation of environmental quality and ecosystem health. In this paper, we summarize the characteristics of nutrient cycling within the urban ecosystem compared to natural ecosystems. The dynamic process of nutrient urbanization is then explored taking Xiamen city, China, as an example to examine the influence of rapid urbanization on food sourced nitrogen and phosphorus metabolism. Subsequently, the concept of a nutrient footprint and calculation method is introduced from a lifecycle perspective. Finally, we propose three system approaches to mend the broken biogeochemical cycling. Our study will contribute to a holistic solution which achieves synergies between environmental quality and food security, by integrating technologies for nutrient recovery and waste reduction. Copyright © 2014 Elsevier Ltd. All rights reserved.

Nutrient-induced intestinal adaption and its effect in obesity.

PubMed

Dailey, Megan J

2014-09-01

Obese and lean individuals respond differently to nutrients with changes in digestion, absorption and hormone release. This may be a result of differences in intestinal epithelial morphology and function driven by the hyperphagia or the type of diet associated with obesity. It is well known that the maintenance and growth of the intestine is driven by the amount of luminal nutrients, with high nutrient content resulting in increases in cell number, villi length and crypt depth. In addition, the type of nutrient appears to contribute to alterations in the morphology and function of the epithelial cells. This intestinal adaptation may be what is driving the differences in nutrient processing in lean versus obese individuals. This review describes how nutrients may be able to induce changes in intestinal epithelial cell proliferation, differentiation and function and the link between intestinal adaptation and obesity. Copyright © 2014 Elsevier Inc. All rights reserved.

The mineral content of tap water in United States households

USDA-ARS?s Scientific Manuscript database

The composition of tap water contributes to dietary intake of minerals. The USDA’s Nutrient Data Laboratory (NDL) conducted a study of the mineral content of residential tap water, to generate current data for the USDA National Nutrient Database. Sodium, potassium, calcium, magnesium, iron, copper...

Does conservation on farmland contribute to halting the biodiversity decline?

PubMed

Kleijn, David; Rundlöf, Maj; Scheper, Jeroen; Smith, Henrik G; Tscharntke, Teja

2011-09-01

Biodiversity continues to decline, despite the implementation of international conservation conventions and measures. To counteract biodiversity loss, it is pivotal to know how conservation actions affect biodiversity trends. Focussing on European farmland species, we review what is known about the impact of conservation initiatives on biodiversity. We argue that the effects of conservation are a function of conservation-induced ecological contrast, agricultural land-use intensity and landscape context. We find that, to date, only a few studies have linked local conservation effects to national biodiversity trends. It is therefore unknown how the extensive European agri-environmental budget for conservation on farmland contributes to the policy objectives to halt biodiversity decline. Based on this review, we identify new research directions addressing this important knowledge gap. Copyright © 2011 Elsevier Ltd. All rights reserved.

Seasonality directs contrasting food collection behavior and nutrient regulation strategies in ants.

PubMed

Cook, Steven C; Eubanks, Micky D; Gold, Roger E; Behmer, Spencer T

2011-01-01

Long-lived animals, including social insects, often display seasonal shifts in foraging behavior. Foraging is ultimately a nutrient consumption exercise, but the effect of seasonality per se on changes in foraging behavior, particularly as it relates to nutrient regulation, is poorly understood. Here, we show that field-collected fire ant colonies, returned to the laboratory and maintained under identical photoperiod, temperature, and humidity regimes, and presented with experimental foods that had different protein (p) to carbohydrate (c) ratios, practice summer- and fall-specific foraging behaviors with respect to protein-carbohydrate regulation. Summer colonies increased the amount of food collected as the p:c ratio of their food became increasingly imbalanced, but fall colonies collected similar amounts of food regardless of the p:c ratio of their food. Choice experiments revealed that feeding was non-random, and that both fall and summer ants preferred carbohydrate-biased food. However, ants rarely ate all the food they collected, and their cached or discarded food always contained little carbohydrate relative to protein. From a nutrient regulation strategy, ants consumed most of the carbohydrate they collected, but regulated protein consumption to a similar level, regardless of season. We suggest that varied seasonal food collection behaviors and nutrient regulation strategies may be an adaptation that allows long-lived animals to meet current and future nutrient demands when nutrient-rich foods are abundant (e.g. spring and summer), and to conserve energy and be metabolically more efficient when nutritionally balanced foods are less abundant.

Seasonality Directs Contrasting Food Collection Behavior and Nutrient Regulation Strategies in Ants

PubMed Central

Cook, Steven C.; Eubanks, Micky D.; Gold, Roger E.; Behmer, Spencer T.

2011-01-01

Long-lived animals, including social insects, often display seasonal shifts in foraging behavior. Foraging is ultimately a nutrient consumption exercise, but the effect of seasonality per se on changes in foraging behavior, particularly as it relates to nutrient regulation, is poorly understood. Here, we show that field-collected fire ant colonies, returned to the laboratory and maintained under identical photoperiod, temperature, and humidity regimes, and presented with experimental foods that had different protein (p) to carbohydrate (c) ratios, practice summer- and fall-specific foraging behaviors with respect to protein-carbohydrate regulation. Summer colonies increased the amount of food collected as the p:c ratio of their food became increasingly imbalanced, but fall colonies collected similar amounts of food regardless of the p:c ratio of their food. Choice experiments revealed that feeding was non-random, and that both fall and summer ants preferred carbohydrate-biased food. However, ants rarely ate all the food they collected, and their cached or discarded food always contained little carbohydrate relative to protein. From a nutrient regulation strategy, ants consumed most of the carbohydrate they collected, but regulated protein consumption to a similar level, regardless of season. We suggest that varied seasonal food collection behaviors and nutrient regulation strategies may be an adaptation that allows long-lived animals to meet current and future nutrient demands when nutrient-rich foods are abundant (e.g. spring and summer), and to conserve energy and be metabolically more efficient when nutritionally balanced foods are less abundant. PMID:21966522

Sensitivity Analysis in Agent-Based Models of Socio-Ecological Systems: An Example in Agricultural Land Conservation for Lake Water Quality Improvement

NASA Astrophysics Data System (ADS)

Ligmann-Zielinska, A.; Kramer, D. B.; Spence Cheruvelil, K.; Soranno, P.

2012-12-01

Socio-ecological systems are dynamic and nonlinear. To account for this complexity, we employ agent-based models (ABMs) to study macro-scale phenomena resulting from micro-scale interactions among system components. Because ABMs typically have many parameters, it is challenging to identify which parameters contribute to the emerging macro-scale patterns. In this paper, we address the following question: What is the extent of participation in agricultural land conservation programs given heterogeneous landscape, economic, social, and individual decision making criteria in complex lakesheds? To answer this question, we: [1] built an ABM for our model system; [2] simulated land use change resulting from agent decision making, [3] estimated the uncertainty of the model output, decomposed it and apportioned it to each of the parameters in the model. Our model system is a freshwater socio-ecological system - that of farmland and lake water quality within a region containing a large number of lakes and high proportions of agricultural lands. Our study focuses on examining how agricultural land conversion from active to fallow reduces freshwater nutrient loading and improves water quality. Consequently, our ABM is composed of farmer agents who make decisions related to participation in a government-sponsored Conservation Reserve Program (CRP) managed by the Farm Service Agency (FSA). We also include an FSA agent, who selects enrollment offers made by farmers and announces the signup results leading to land use change. The model is executed in a Monte Carlo simulation framework to generate a distribution of maps of fallow lands that are used for calculating nutrient loading to lakes. What follows is a variance-based sensitivity analysis of the results. We compute sensitivity indices for individual parameters and their combinations, allowing for identification of the most influential as well as the insignificant inputs. In the case study, we observe that farmland conservation is first and foremost driven by the FSA signup choices. Environmental criteria used in FSA offer selection play a secondary role in farmland-to-fallow-land conversion. Farmer decision making is mainly influenced by the willingness to reduce the potential annual rental payments. As the case study demonstrates, our approach leads to ABM simplification without the loss of outcome variability. It also shows how to represent the magnitude of ABM complexity and isolate the effects of the interconnected explanatory variables on the simulated emergent phenomena. More importantly, the results of our research indicate that some of the parameters exert influence on model outcomes only if analyzed in combination with other parameters. Without evaluating the interaction effects among inputs, we risk losing important functional relationships among ABM components and, consequently, we potentially reduce its explanatory power.

Digital data used to relate nutrient inputs to water quality in the Chesapeake Bay watershed, version 3.0

USGS Publications Warehouse

Brakebill, John W.; Preston, Stephen D.

2004-01-01

Chesapeake Bay restoration efforts are focused on improving water quality, living resources, and ecological habitats by 2010. One aspect of the water-quality restoration is the refinement of strategies designed to implement nutrient-reduction practices within the Bay watershed. These strategies are being refined and implemented by resource managers of the Chesapeake Bay Program (CBP), a partnership comprised of various Federal, State, and local agencies that includes jurisdictions within Delaware, Maryland, New York, Pennsylvania, Virginia, West Virginia, and the District of Columbia. The U.S. Geological Survey (USGS), an active member of the CBP, provides necessary water-quality information for these Chesapeake Bay nutrient-reduction strategy revisions and evaluations. The formulation and revision of effective nutrient-reduction strategies requires detailed scientific information and an analytical understanding of the sources, transport, and delivery of nutrients to the Chesapeake Bay. The USGS is supporting these strategies by providing scientific information to resource managers that can help them evaluate and understand these processes. One statistical model available to resource managers is a collection of SPAtially Referenced Regressions On Watershed (SPARROW) attributes, which uses a nonlinear regression approach to spatially relate nutrient sources and watershed characteristics to nutrient loads of streams throughout the Chesapeake Bay watershed. Developed by the USGS, information generated by SPARROW can help resource managers determine the geographical distribution and relative contribution of nutrient sources and the factors that affect their transport to the Bay. Nutrient source information representing the late 1990s time period was obtained from several agencies and used to create and compile digital spatial datasets of total nitrogen and total phosphorus contributions that served as input sources to the SPARROW models. These data represent atmospheric deposition, point-source locations, land-use, land-cover, and agricultural sources such as commercial fertilizer and manure applications. Watershed-characteristics datasets representing factors that affect the transport of nutrients also were compiled from previous applications of the SPARROW models in the Chesapeake Bay watershed. Datasets include average-annual precipitation and temperature, slope, soil permeability, and hydrogeomorphic regions. Nutrient-input and watershed-characteristics datasets representing conditions during the late 1990s were merged with a connected network of stream reaches and watersheds to provide the spatial detail required by SPARROW. Stream-nutrient load estimates for 125 sampling sites (87 for total nitrogen and 103 for total phosphorus) served as the dependent variables for the regressions, and were used to calibrate models of total nitrogen and total phosphorus depicting late 1990s conditions in the Chesapeake Bay watershed. Spatial data generated for the models can be used to identify the location of nutrient sources, while the models' nutrient estimates can be used to evaluate stream-nutrient load contributed locally by each source evaluated, the amount of local load generated that is transported to the Bay, and the factors that affect the nutrient transport. Applying the SPARROW methodology to late 1990s information completes three time periods (late 1980s, early 1990s, and late 1990s) of viable data that resource managers can use to evaluate the water-quality conditions within the Bay watershed in order to refine restoration goals and nutrient-reduction strategies.

Implementing the millennium development food security goals Challenges of the southern African context

NASA Astrophysics Data System (ADS)

Love, David; Twomlow, Steve; Mupangwa, Walter; van der Zaag, Pieter; Gumbo, Bekithemba

The Millennium Development Goals’ target to halve the proportion of people who suffer from hunger is extremely important in southern Africa, where food security has become increasingly problematic over the last 20 years. One “quick-win” proposal is replenishment of soil nutrients for smallholder farmers, through free or subsidised chemical fertilisers. Other proposals include appropriate irrigation technology, improved inputs and interventions targeted at women. Analysis of over 10 years of agro-hydrological and agro-economic studies from southern African show that a different approach is required to interventions proposed. There are sustainability problems with free chemical fertiliser due to transport costs and ancillary costs. Furthermore, recent studies in Zimbabwe and Mozambique show that significant increases in yield can only be obtained when soil fertility management is combined with good crop husbandry, e.g. timely planting and weeding. Ongoing replenishment of fertility would be dependent on a continued free or subsidised fertiliser supply, and transport system. Increasing access to irrigation will help, but is not the only solution and cannot reach even a majority of farmers. It has been determined that short dryspells are often the major cause of low yields in sub-Saharan Africa. Soil-water conservation approaches, e.g. winter weeding and conservation tillage, can reduce risk and increase yield. The following specific recommendations are made for urgent interventions to contribute sustainably to food security in southern Africa: (i) To increases access to fertiliser, consider development of strong input markets at end-user level. (ii) Intensification of technology transfer, focusing on capacity building for transfer of existing technologies and much closer collaboration between state and NGO sectors, agronomists and water engineers. (iii) Increasing the uptake of soil-water conservation methods, including conservation tillage and weeding, and supplementary irrigation to minimise adverse effects of dryspells, through investments in farmer training. (iv) Linking crop development strategies to livestock development practices and strategies. (v) Developing non-agro-based livelihood strategies in marginal lands.

The Nuclear Receptor DAF-12 Regulates Nutrient Metabolism and Reproductive Growth in Nematodes

PubMed Central

Wang, Zhu; Stoltzfus, Jonathan; You, Young-jai; Ranjit, Najju; Tang, Hao; Xie, Yang; Lok, James B.; Mangelsdorf, David J.; Kliewer, Steven A.

2015-01-01

Appropriate nutrient response is essential for growth and reproduction. Under favorable nutrient conditions, the C. elegans nuclear receptor DAF-12 is activated by dafachronic acids, hormones that commit larvae to reproductive growth. Here, we report that in addition to its well-studied role in controlling developmental gene expression, the DAF-12 endocrine system governs expression of a gene network that stimulates the aerobic catabolism of fatty acids. Thus, activation of the DAF-12 transcriptome coordinately mobilizes energy stores to permit reproductive growth. DAF-12 regulation of this metabolic gene network is conserved in the human parasite, Strongyloides stercoralis, and inhibition of specific steps in this network blocks reproductive growth in both of the nematodes. Our study provides a molecular understanding for metabolic adaptation of nematodes to their environment, and suggests a new therapeutic strategy for treating parasitic diseases. PMID:25774872

Carbon and nitrogen mineralization and persistence of organic residues under conservation and conventional tillage

USDA-ARS?s Scientific Manuscript database

A combination of high biomass cover crops with organic mulches may be an option for no-till vegetable production, but mineralization rates from these residues is lacking. The objective of this study was to assess nutrient release rates and persistence from mimosa, lespedeza, oat straw, and soybean r...

Impact of nonnative feral pig removal on soil structure and nutrient availability in Hawaiian tropical montane wet forests

Treesearch

Michael S. Long; Creighton M. Litton; Christian P. Giardina; Jonathan Deenik; Rebecca J. Cole; Jed P. Sparks

2017-01-01

Conservation and restoration of ecosystems impacted by nonnative ungulates increasingly involves their removal and exclusion. While the influence of nonnative ungulate removal on plant communities is commonly monitored, impacts on underlying ecological processes are seldom quantified. Here we examined how nonnative feral pig (

Evaluating the Soil Vulnerability Index (SVI), an index to characterize inherent vulnerability of croplands to runoff and leaching

USDA-ARS?s Scientific Manuscript database

Soil erosion and nutrient loss from surface runoff and sub-surface flows are critical problems for croplands in the United States. Assessing cropland vulnerability to runoff and leaching is needed for watershed or regional land use and land management planning and conservation resources allocation. ...

Energy use and greenhouse gas emissions in organic and conventional grain crop production: accounting for nutrient inflows

USDA-ARS?s Scientific Manuscript database

Agriculture is a large source of greenhouse gas (GHG) emissions with large energy requirements. Previous research has shown that organic farming and conservation tillage practices can reduce environmental impacts from agriculture. We used the Farm Energy Analysis Tool (FEAT) to quantify the energy u...

Keeping Sediment and Nutrients out of Streams in Arid/Semi-Arid United States: Application of Low Impact Development/Green Infrastructure Practices

EPA Science Inventory

Climatic and hydrological characteristics in the arid/semi-arid areas create unique challenges to soil, water and biodiversity conservation. These areas are environmentally sensitive, but very valuable for the ecosystems services they provide to society. Some of these areas are...

Forging the Link: Using a Conservative Mixing Framework to Characterize Connections between Rivers and Great Lakes in River-lake Transition Zones

EPA Science Inventory

River-to-Great Lake transition zones are hydrologically, biogeochemically and biologically dynamic areas that regulate nutrient and energy fluxes between rivers and Great Lakes. Our goal is to characterize the biogeochemical properties of the river-lake transition zones and under...

Water quality ramifications of manure storage and daily haul during winter and early spring

USDA-ARS?s Scientific Manuscript database

Manure storage is supported by the United States Natural Resources Conservation Service (NRCS) as a nutrient management strategy for controlling air and water quality. Daily haul is still a popular practice on the small farms in northeastern USA but receives criticism over the impact of spreading du...

Woody biomass from short rotation energy crops. Chapter 2

Treesearch

R.S., Jr. Zalesny Jr.; M.W. Cunningham; R.B. Hall; J. Mirck; D.L. Rockwood; J.A. Stanturf; T.A. Volk

2011-01-01

Short rotation woody crops (SRWCs) are ideal for woody biomass production and management systems because they are renewable energy feedstocks for biofuels, bioenergy, and bioproducts that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. This chapter is a synthesis of the regional implications of producing...

Woody biomass from short rotation energy crops

Treesearch

R.S. Zalesny; M.W. Cunningham; R.B. Hall; J. Mirck; D.L. Rockwood; John Stanturf; T.A. Volk

2011-01-01

Short rotation woody crops (SRWCs) are ideal for woody biomass production and management systems because they are renewable energy feedstocks for biofuels, bioenergy, and bioproducts that can be strategically placed in the landscape to conserve soil and water, recycle nutrients, and sequester carbon. This chapter is a synthesis of the regional implications of producing...

Dissolved nitrogen, chloride, and potassium loss from fields in conventional and conservation tillage

USDA-ARS?s Scientific Manuscript database

Losses of soluble nutrients from cropland and their transport to surface and groundwater are a continuing water quality concern. In this study we evaluated tillage impact on dissolved losses of ammonium (NH4-N) and nitrate nitrogen (NO3-N), chloride (Cl), and potassium (K) during rotational cotton ...

Alfalfa interseeded into silage corn can enhance productivity and soil and water conservation

USDA-ARS?s Scientific Manuscript database

Alfalfa and corn silage are widely planted for dairy forage production systems throughout the northern regions of the USA, accounting for about 0.8 and 1.9 million hectares per year, respectively. Much of this area could benefit from strategies to reduce soil erosion and nutrient losses. Because the...

Cost of areal reduction of gulf hypoxia through agricultural practice

USDA-ARS?s Scientific Manuscript database

A major share of the area of hypoxic growth in the Northern Gulf of Mexico has been attributed to nutrient run-off from agricultural fields, but no estimate is available for the cost of reducing Gulf hypoxic area using agricultural conservation practices. We apply the Soil and Water Assessment Tool ...

Tanshinones extend chronological lifespan in budding yeast Saccharomyces cerevisiae.

PubMed

Wu, Ziyun; Song, Lixia; Liu, Shao Quan; Huang, Dejian

2014-10-01

Natural products with anti-aging property have drawn great attention recently but examples of such compounds are exceedingly scarce. By applying a high-throughput assay based on yeast chronological lifespan measurement, we screened the anti-aging activity of 144 botanical materials and found that dried roots of Salvia miltiorrhiza Bunge have significant anti-aging activity. Tanshinones isolated from the plant including cryptotanshione, tanshinone I, and tanshinone IIa, are the active components. Among them, cryptotanshinone can greatly extend the budding yeast Saccharomyces cerevisiae chronological lifespan (up to 2.5 times) in a dose- and the-time-of-addition-dependent manner at nanomolar concentrations without disruption of cell growth. We demonstrate that cryptotanshinone prolong chronological lifespan via a nutrient-dependent regime, especially essential amino acid sensing, and three conserved protein kinases Tor1, Sch9, and Gcn2 are required for cryptotanshinone-induced lifespan extension. In addition, cryptotanshinone significantly increases the lifespan of SOD2-deleted mutants. Altogether, those data suggest that cryptotanshinone might be involved in the regulation of, Tor1, Sch9, Gcn2, and Sod2, these highly conserved longevity proteins modulated by nutrients from yeast to humans.

Nutrient contribution of the dinner meal consumed by low-income minority preschool children

USDA-ARS?s Scientific Manuscript database

The goal of this study was to examine the energy and nutrient intake of dinner of low-income preschool minority groups, African-Americans and Mexican-Americans, attending Head Start. A cross-sectional study of intake at dinner using digital photography was undertaken. Pictorial records were converte...

Corn yield and nutrient uptake response to subsurface-lateral bands application of poultry litter

USDA-ARS?s Scientific Manuscript database

Poultry litter is nutrient rich and traditionally land-applied by broadcast on the soil surface which can lead to potential environmental hazards. This application method leaves PL vulnerable to transport from the field to nearby water bodies and contributes significant amounts of greenhouse gases (...

Ultrasonic Spray Drying vs High Vacuum and Microwaves Technology for Blueberries

NASA Astrophysics Data System (ADS)

Candia-Muñoz, N.; Ramirez-Bunster, M.; Vargas-Hernández, Y.; Gaete-Garretón, L.

Interest in high quality foods: good taste and a high content of nutrients with healthy beneficial effects are increasing. Fruits have good properties but, they are lost because the oxidation process, additionally, for different reasons a 40% of harvested fruit are lost. To conserve the fruit properties an ultrasonic assisted spray dryer was developed and tested, comparing its results with microwave-vacuum drying technology. Results did shown taste, color, smell, particle shape and size distribution better than the conventional one. The antioxidants conservation were quite good except in the anthocyanins, in which the microwave and vacuum technology shown best results.

Nutritional composition of honey bee food stores vary with floral composition.

PubMed

Donkersley, Philip; Rhodes, Glenn; Pickup, Roger W; Jones, Kevin C; Power, Eileen F; Wright, Geraldine A; Wilson, Kenneth

2017-12-01

Sufficiently diverse and abundant resources are essential for generalist consumers, and form an important part of a suite of conservation strategies for pollinators. Honey bees are generalist foragers and are dependent on diverse forage to adequately meet their nutritional needs. Through analysis of stored pollen (bee bread) samples obtained from 26 honey bee (Apis mellifera L.) hives across NW-England, we quantified bee bread nutritional content and the plant species that produced these stores from pollen. Protein was the most abundant nutrient by mass (63%), followed by carbohydrates (26%). Protein and lipid content (but not carbohydrate) contributed significantly to ordinations of floral diversity, linking dietary quality with forage composition. DNA sequencing of the ITS2 region of the nuclear ribosomal DNA gene identified pollen from 89 distinct plant genera, with each bee bread sample containing between 6 and 35 pollen types. Dominant genera included dandelion (Taraxacum), which was positively correlated with bee bread protein content, and cherry (Prunus), which was negatively correlated with the amount of protein. In addition, proportions of amino acids (e.g. histidine and valine) varied as a function of floral species composition. These results also quantify the effects of individual plant genera on the nutrition of honey bees. We conclude that pollens of different plants act synergistically to influence host nutrition; the pollen diversity of bee bread is linked to its nutrient content. Diverse environments compensate for the loss of individual forage plants, and diversity loss may, therefore, destabilize consumer communities due to restricted access to alternative resources.

Relation of nutrient concentrations, nutrient loading, and algal production to changes in water levels in Kabetogama Lake, Voyageurs National Park, northern Minnesota, 2008-09

USGS Publications Warehouse

Christensen, Victoria G.; Maki, Ryan P.; Kiesling, Richard L.

2011-01-01

Nutrient enrichment has led to excessive algal growth in Kabetogama Lake, Voyageurs National Park, northern Minnesota. Water- and sediment-quality data were collected during 2008-09 to assess internal and external nutrient loading. Data collection was focused in Kabetogama Lake and its inflows, the area of greatest concern for eutrophication among the lakes of Voyageurs National Park. Nutrient and algal data were used to determine trophic status and were evaluated in relation to changes in Kabetogama Lake water levels following changes to dam operation starting in 2000. Analyses were used to estimate external nutrient loading at inflows and assess the potential contribution of internal phosphorus loading. Kabetogama Lake often was mixed vertically, except for a few occasionally stratified areas, including Lost Bay in the northeastern part of Kabetogama Lake. Stratification, combined with larger bottom-water nutrient concentrations, larger sediment phosphorus concentrations, and estimated phosphorus release rates from sediment cores indicate that Lost Bay may be one of several areas that may be contributing substantially to internal loading. Internal loading is a concern because nutrients may cause excessive algal growth including potentially toxic cyanobacteria. The cyanobacterial hepatotoxin, microcystin, was detected in 7 of 14 cyanobacterial bloom samples, with total concentrations exceeding 1.0 microgram per liter, the World Health Organization's guideline for finished drinking water for the congener, microcystin-LR. Comparisons of the results of this study to previous studies indicate that chlorophyll-a concentrations and trophic state indices have improved since 2000, when the rules governing dam operation changed. However, total-phosphorus concentrations have not changed significantly since 2000.

Contribution of trees and grasses to ecosystem fluxes of water, carbon, and energy throughout the seasons under different nutrient availability

NASA Astrophysics Data System (ADS)

El-Madany, T. S.; Migliavacca, M.; Perez-Priego, O.; Luo, Y.; Moreno, G.; Carrara, A.; Kolle, O.; Reichstein, M.

2017-12-01

In semi-arid savanna type ecosystems, the carbon and water cycle are closely related to each other. Water availability is the main driver for the development and phenology of the vegetation, especially for annual plants. Depending on tree density, nutrient availability and species the contribution of the tree- and the herbaceous layer to ecosystem fluxes can vary substantially. We present data from an ecosystem scale nutrient manipulation experiment within a Mediterranean savanna type ecosystem which is used for cattle. The footprint areas of two out of three ecosystem eddy co-variance (EC) towers were fertilized with nitrogen (NT) and nitrogen plus phosphorous (NPT) while the third one served as the control tower (CT). At each ecosystem EC-tower an additional herbaceous layer tower was installed that only sampled fluxes from the herbaceous layer. Under certain assumptions flux differences between the ecosystem EC and the herbaceous layer EC systems can be considered as the contribution of the trees to the ecosystem fluxes. Based on phenology of the herbaceous layer estimated through green-chromatic-coordinates from digital imagery the year was separated into spring, senescence, regreening, and winter. The focus of the analysis is (i) the evaluation of the method and how it works throughout the different seasons and (ii) the quantification of the contribution of trees and grasses to ecosystem fluxes of water, carbon, and energy under different environmental conditions and nutrient stoichiometry. The contribution of the trees to total ecosystem fluxes is variable in time. Especially, during the beginning of the senescence period high evapotranspiration rates and largest carbon uptake are measured while the contribution to sensible heat fluxes is largest during the end of the summer. During the regreening and winter the contribution of ET is relatively constant around 0.25 mm d-1. During the peak of the greenness ET and carbon flux of the herbaceous EC tower are sometimes higher than fluxes measured by the ecosystem tower which is most likely caused by the mismatch in footprints. Whenever the herbaceous layer is active it contributes clearly more to the fluxes as compared to the trees.

Sub-soil microbial activity under rotational cotton crops in Australia

NASA Astrophysics Data System (ADS)

Polain, Katherine; Knox, Oliver; Wilson, Brian; Pereg, Lily

2016-04-01

Soil microbial communities contribute significantly to soil organic matter formation, stabilisation and destabilisation, through nutrient cycling and biodegradation. The majority of soil microbial research examines the processes occurring in the top 0 cm to 30 cm of the soil, where organic nutrients are easily accessible. In soils such as Vertosols, the high clay content causes swelling and cracking. When soil cracking is coupled with rain or an irrigation event, a flush of organic nutrients can move down the soil profile, becoming available for subsoil microbial community use and potentially making a significant contribution to nutrient cycling and biodegradation in soils. At present, the mechanisms and rates of soil nutrient turnover (such as carbon and nitrogen) at depth under cotton rotations are mostly speculative and the process-response relationships remain unclear, although they are undoubtedly underpinned by microbial activity. Our research aims to determine the contribution and role of soil microbiota to the accumulation, cycling and mineralisation of carbon and nitrogen through the whole root profile under continuous cotton (Gossypium hirsutum) and cotton-maize rotations in regional New South Wales, Australia. Through seasonal work, we have established both baseline and potential microbial activity rates from 0 cm to 100 cm down the Vertosol profile, using respiration and colourimetric methods. Further whole soil profile analyses will include determination of microbial biomass and isotopic carbon signatures using phospholipid fatty acid (PLFA) methodology, identification of microbial communities (sequencing) and novel experiments to investigate potential rates of nitrogen mineralisation and quantification of associated genes. Our preliminary observations and the hypotheses tested in this three-year study will be presented.

Contribution of natural resources to nutritional status in a protected area of Gabon.

PubMed

Blaney, Sonia; Beaudry, Micheline; Latham, Michael

2009-03-01

In protected areas, legislation restricts the population's access to natural food resources, which might have an impact on their welfare. To assess the contribution of the individual use of natural resources to nutritional status in the rural population of the Gamba Complex of Gabon. Four villages were selected to represent the rural population. All households were invited to participate, and 95% agreed. In each of the two major seasons, data were collected from all individuals (n = 637) in these 95 households during a 7-day period using a weighed food-consumption survey, observations, interviews, and anthropometric measures. Among children 5 to 9 years of age (n = 82) and adolescents (n = 169), their use of natural resources was the best predictor of nutritional status (explaining 8% of the variance), mainly via its contribution to the achievement of nutrient requirements. The use of natural resources was not a predictor for children 6 to 23 months (n = 28) or 24 to 59 months of age (n = 63), where the best predictors were access to care (26%) and health status (15%), respectively. Household food security predicted nutritional status in women caregivers (n = 96), although negatively. Natural resources contribute to the nutritional status of children 5 to 9 years of age and adolescents but not of other groups. The intrahousehold allocation of food, particularly of natural food resources, needs to be investigated to better appreciate the contribution of natural resources to the population's well-being. Women seem particularly vulnerable. Other than activities related to conservation, work is needed to understand the role of natural resources for populations living within and around protected areas.

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

USGS Publications Warehouse

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.

Biogeographic Comparison of Lophelia-Associated Bacterial Communities in the Western Atlantic Reveals Conserved Core Microbiome

PubMed Central

Kellogg, Christina A.; Goldsmith, Dawn B.; Gray, Michael A.

2017-01-01

Over the last decade, publications on deep-sea corals have tripled. Most attention has been paid to Lophelia pertusa, a globally distributed scleractinian coral that creates critical three-dimensional habitat in the deep ocean. The bacterial community associated with L. pertusa has been previously described by a number of studies at sites in the Mediterranean Sea, Norwegian fjords, off Great Britain, and in the Gulf of Mexico (GOM). However, use of different methodologies prevents direct comparisons in most cases. Our objectives were to address intra-regional variation and to identify any conserved bacterial core community. We collected samples from three distinct colonies of L. pertusa at each of four locations within the western Atlantic: three sites within the GOM and one off the east coast of the United States. Amplicon libraries of 16S rRNA genes were generated using primers targeting the V4–V5 hypervariable region and 454 pyrosequencing. The dominant phylum was Proteobacteria (75–96%). At the family level, 80–95% of each sample was comprised of five groups: Pirellulaceae, Pseudonocardiaceae, Rhodobacteraceae, Sphingomonadaceae, and unclassified Oceanospirillales. Principal coordinate analysis based on weighted UniFrac distances showed a clear distinction between the GOM and Atlantic samples. Interestingly, the replicate samples from each location did not always cluster together, indicating there is not a strong site-specific influence. The core bacterial community, conserved in 100% of the samples, was dominated by the operational taxonomic units of genera Novosphingobium and Pseudonocardia, both known degraders of aromatic hydrocarbons. The sequence of another core member, Propionibacterium, was also found in prior studies of L. pertusa from Norway and Great Britain, suggesting a role as a conserved symbiont. By examining more than 40,000 sequences per sample, we found that GOM samples were dominated by the identified conserved core sequences, whereas open Atlantic samples had a much higher proportion of locally consistent bacteria. Further, predictive functional profiling highlights the potential for the L. pertusa microbiome to contribute to chemoautotrophy, nutrient cycling, and antibiotic production. PMID:28522997

Biogeographic Comparison of Lophelia-Associated Bacterial Communities in the Western Atlantic Reveals Conserved Core Microbiome.

PubMed

Kellogg, Christina A; Goldsmith, Dawn B; Gray, Michael A

2017-01-01

Over the last decade, publications on deep-sea corals have tripled. Most attention has been paid to Lophelia pertusa , a globally distributed scleractinian coral that creates critical three-dimensional habitat in the deep ocean. The bacterial community associated with L. pertusa has been previously described by a number of studies at sites in the Mediterranean Sea, Norwegian fjords, off Great Britain, and in the Gulf of Mexico (GOM). However, use of different methodologies prevents direct comparisons in most cases. Our objectives were to address intra-regional variation and to identify any conserved bacterial core community. We collected samples from three distinct colonies of L. pertusa at each of four locations within the western Atlantic: three sites within the GOM and one off the east coast of the United States. Amplicon libraries of 16S rRNA genes were generated using primers targeting the V4-V5 hypervariable region and 454 pyrosequencing. The dominant phylum was Proteobacteria (75-96%). At the family level, 80-95% of each sample was comprised of five groups: Pirellulaceae, Pseudonocardiaceae, Rhodobacteraceae, Sphingomonadaceae, and unclassified Oceanospirillales. Principal coordinate analysis based on weighted UniFrac distances showed a clear distinction between the GOM and Atlantic samples. Interestingly, the replicate samples from each location did not always cluster together, indicating there is not a strong site-specific influence. The core bacterial community, conserved in 100% of the samples, was dominated by the operational taxonomic units of genera Novosphingobium and Pseudonocardia , both known degraders of aromatic hydrocarbons. The sequence of another core member, Propionibacterium , was also found in prior studies of L. pertusa from Norway and Great Britain, suggesting a role as a conserved symbiont. By examining more than 40,000 sequences per sample, we found that GOM samples were dominated by the identified conserved core sequences, whereas open Atlantic samples had a much higher proportion of locally consistent bacteria. Further, predictive functional profiling highlights the potential for the L. pertusa microbiome to contribute to chemoautotrophy, nutrient cycling, and antibiotic production.

Biogeographic comparison of Lophelia-associated bacterial communities in the Western Atlantic reveals conserved core microbiome

USGS Publications Warehouse

Kellogg, Christina A.; Goldsmith, Dawn; Gray, Michael A.

2017-01-01

Over the last decade, publications on deep-sea corals have tripled. Most attention has been paid to Lophelia pertusa, a globally distributed scleractinian coral that creates critical three-dimensional habitat in the deep ocean. The bacterial community associated with L. pertusa has been previously described by a number of studies at sites in the Mediterranean Sea, Norwegian fjords, off Great Britain, and in the Gulf of Mexico (GOM). However, use of different methodologies prevents direct comparisons in most cases. Our objectives were to address intra-regional variation and to identify any conserved bacterial core community. We collected samples from three distinct colonies of L. pertusa at each of four locations within the western Atlantic: three sites within the GOM and one off the east coast of the United States. Amplicon libraries of 16S rRNA genes were generated using primers targeting the V4–V5 hypervariable region and 454 pyrosequencing. The dominant phylum was Proteobacteria (75–96%). At the family level, 80–95% of each sample was comprised of five groups: Pirellulaceae, Pseudonocardiaceae, Rhodobacteraceae, Sphingomonadaceae, and unclassified Oceanospirillales. Principal coordinate analysis based on weighted UniFrac distances showed a clear distinction between the GOM and Atlantic samples. Interestingly, the replicate samples from each location did not always cluster together, indicating there is not a strong site-specific influence. The core bacterial community, conserved in 100% of the samples, was dominated by the operational taxonomic units of genera Novosphingobium and Pseudonocardia, both known degraders of aromatic hydrocarbons. The sequence of another core member, Propionibacterium, was also found in prior studies of L. pertusa from Norway and Great Britain, suggesting a role as a conserved symbiont. By examining more than 40,000 sequences per sample, we found that GOM samples were dominated by the identified conserved core sequences, whereas open Atlantic samples had a much higher proportion of locally consistent bacteria. Further, predictive functional profiling highlights the potential for the L. pertusa microbiome to contribute to chemoautotrophy, nutrient cycling, and antibiotic production.

Deciduous and evergreen trees differ in juvenile biomass allometries because of differences in allocation to root storage.

PubMed

Tomlinson, Kyle W; van Langevelde, Frank; Ward, David; Bongers, Frans; da Silva, Dulce Alves; Prins, Herbert H T; de Bie, Steven; Sterck, Frank J

2013-08-01

Biomass partitioning for resource conservation might affect plant allometry, accounting for a substantial amount of unexplained variation in existing plant allometry models. One means of resource conservation is through direct allocation to storage in particular organs. In this study, storage allocation and biomass allometry of deciduous and evergreen tree species from seasonal environments were considered. It was expected that deciduous species would have greater allocation to storage in roots to support leaf regrowth in subsequent growing seasons, and consequently have lower scaling exponents for leaf to root and stem to root partitioning, than evergreen species. It was further expected that changes to root carbohydrate storage and biomass allometry under different soil nutrient supply conditions would be greater for deciduous species than for evergreen species. Root carbohydrate storage and organ biomass allometries were compared for juveniles of 20 savanna tree species of different leaf habit (nine evergreen, 11 deciduous) grown in two nutrient treatments for periods of 5 and 20 weeks (total dry mass of individual plants ranged from 0·003 to 258·724 g). Deciduous species had greater root non-structural carbohydrate than evergreen species, and lower scaling exponents for leaf to root and stem to root partitioning than evergreen species. Across species, leaf to stem scaling was positively related, and stem to root scaling was negatively related to root carbohydrate concentration. Under lower nutrient supply, trees displayed increased partitioning to non-structural carbohydrate, and to roots and leaves over stems with increasing plant size, but this change did not differ between leaf habits. Substantial unexplained variation in biomass allometry of woody species may be related to selection for resource conservation against environmental stresses, such as resource seasonality. Further differences in plant allometry could arise due to selection for different types of biomass allocation in response to different environmental stressors (e.g. fire vs. herbivory).

From salmon to shad: Shifting sources of marine-derived nutrients in the Columbia River Basin

USGS Publications Warehouse

Haskell, Craig A.

2018-01-01

Like Pacific salmon (Oncorhynchus spp.), nonnative American shad (Alosa sapidissima) have the potential to convey large quantities of nutrients between the Pacific Ocean and freshwater spawning areas in the Columbia River Basin (CRB). American shad are now the most numerous anadromous fish in the CRB, yet the magnitude of the resulting nutrient flux owing to the shift from salmon to shad is unknown. Nutrient flux models revealed that American shad conveyed over 15,000 kg of nitrogen (N) and 3,000 kg of phosphorus (P) annually to John Day Reservoir, the largest mainstem reservoir in the lower Columbia River. Shad were net importers of N, with juveniles and postspawners exporting just 31% of the N imported by adults. Shad were usually net importers of P, with juveniles and postspawners exporting 46% of the P imported by adults on average. American shad contributed <0.2% of the total annual P load into John Day Reservoir, but during June when most adult shad are migrating into John Day Reservoir, they contributed as much as 2.0% of the P load. Nutrient inputs by American shad were similar to current but far less than historical inputs of Pacific salmon owing to their smaller size. Given the relatively high background P levels and low retention times in lower Columbia River reservoirs, it is unlikely that shad marine-derived nutrients affect nutrient balances or food web productivity through autotrophic pathways. However, a better understanding of shad spawning aggregations in the CRB is needed.

An individual-based modeling approach to simulate the effects of cellular nutrient competition on Escherichia coli K-12 MG1655 colony behavior and interactions in aerobic structured food systems.

PubMed

Tack, Ignace L M M; Logist, Filip; Noriega Fernández, Estefanía; Van Impe, Jan F M

2015-02-01

Traditional kinetic models in predictive microbiology reliably predict macroscopic dynamics of planktonically-growing cell cultures in homogeneous liquid food systems. However, most food products have a semi-solid structure, where microorganisms grow locally in colonies. Individual colony cells exhibit strongly different and non-normally distributed behavior due to local nutrient competition. As a result, traditional models considering average population behavior in a homogeneous system do not describe colony dynamics in full detail. To incorporate local resource competition and individual cell differences, an individual-based modeling approach has been applied to Escherichia coli K-12 MG1655 colonies, considering the microbial cell as modeling unit. The first contribution of this individual-based model is to describe single colony growth under nutrient-deprived conditions. More specifically, the linear and stationary phase in the evolution of the colony radius, the evolution from a disk-like to branching morphology, and the emergence of a starvation zone in the colony center are simulated and compared to available experimental data. These phenomena occur earlier at more severe nutrient depletion conditions, i.e., at lower nutrient diffusivity and initial nutrient concentration in the medium. Furthermore, intercolony interactions have been simulated. Higher inoculum densities lead to stronger intercolony interactions, such as colony merging and smaller colony sizes, due to nutrient competition. This individual-based model contributes to the elucidation of characteristic experimentally observed colony behavior from mechanistic information about cellular physiology and interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Urban stormwater run-off promotes compression of saltmarshes by freshwater plants and mangrove forests.

PubMed

Geedicke, Ina; Oldeland, Jens; Leishman, Michelle R

2018-05-08

Subtropical and temperate coastal saltmarsh of Australia is listed as an endangered ecological community under the Commonwealth Environment Protection and Biodiversity Conservation Act (EPBC Act). Saltmarshes are under threat from sea level rise, landward migration of mangroves, and in urban regions from habitat loss, input of litter, nutrients, and other contaminants. In urbanised catchments, saltmarsh areas receive nutrient-enriched and pollutant-contaminated run-off, such as heavy metals, through the stormwater system. This study aimed to investigate the impact of urban stormwater on saltmarsh and mangrove species composition and distribution. To test the effect of stormwater run-off in urbanised catchments on saltmarsh communities, we analysed the soil for pollutant elements, salinity and nutrient concentration and recorded vegetation composition at eight sites in the Sydney region, Australia. We found that elevated total nitrogen (>0.4 wt%) and reduced salinity of the soil downslope of stormwater outlets facilitates establishment of exotic plants and might promote migration of mangroves into saltmarshes, resulting in a squeezing effect on the distribution of saltmarsh vegetation. Saltmarsh cover was significantly lower below stormwater outlets and exotic plant cover increased significantly with sediment calcium concentrations above 8840 mg/kg, which are associated with stormwater run-off. However, this effect was found to be strongest in highly industrialised areas compared to residential areas. Understanding the impact of pollutants on coastal wetlands will improve management strategies for the conservation of this important endangered ecological community. Copyright © 2018 Elsevier B.V. All rights reserved.

Nutrigenetics/Nutrigenomics.

PubMed

Simopoulos, Artemis P

2010-01-01

All diseases have a genetic predisposition. Genome-wide association studies (GWASs) by large international consortia are discovering genetic variants that contribute to complex diseases. However, nutrient information is missing, which is essential for the development of dietary advice for prevention and management of disease. Nutrigenetics/nutrigenomics studies provide data on mechanisms of nutrient and gene interactions in health and disease needed for personalized nutrition. A process will be needed to define when gene-nutrient-disease associations are ready to be evaluated as potential tools to improve public health.

Temporal changes in nitrogen and phosphorus concentrations with comparisons to conservation practices and agricultural activities in the Lower Grand River, Missouri and Iowa, and selected watersheds, 1969–2015

USGS Publications Warehouse

Krempa, Heather M.; Flickinger, Allison K.

2017-08-01

This report presents the results of a cooperative study by the U.S. Geological Survey and Missouri Department of Natural Resources to estimate total nitrogen (TN) and total phosphorus (TP) concentrations at monitoring sites within and near the Lower Grand River hydrological unit. The primary objectives of the study were to quantify temporal changes in TN and TP concentrations and compare those concentrations to conservation practices and agricultural activities. Despite increases in funding during 2011–15 for conservation practices in the Lower Grand River from the Mississippi River Basin Healthy Watersheds Initiative, decreases in flow-normalized TN and TP concentrations during this time at the long-term Grand River site were less than at other long-term sites, which did not receive funding from the Mississippi River Basin Healthy Watersheds Initiative. The relative differences in the magnitude of flow-normalized TN and TP concentrations among long-term sites are directly related to the amount of agricultural land use within the watershed. Significant relations were determined between nitrogen from cattle manure and flow-normalized TN concentrations at selected long-term sites, indicating livestock manure may be a substantial source of nitrogen within the selected long-term site watersheds. Relations between flow-normalized TN and TP concentrations with Conservation Reserve Program acres and with nitrogen and phosphorus from commercial fertilizer indicate that changes in these factors alone did not have a substantial effect on stream TN and TP concentrations; other landscape activities, runoff, within-bank nutrients that are suspended during higher streamflows, or a combination of these have had a greater effect on stream TN and TP concentrations; or there is a lag time that is obscuring relations. Temporal changes in flow-adjusted TN and TP concentrations were not substantial at Lower Grand River Mississippi River Basin Healthy Watersheds Initiative sites, indicating factors besides stream variability did not have substantial effects on TN and TP concentrations. Flow-weighted TN and TP concentrations at Lower Grand River Mississippi River Basin Healthy Watershed Initiative sites increase with increasing streamflow, which indicates runoff, within-bank nutrients that are suspended during higher streamflows, or both, have more effect on stream TN and TP concentrations than consistent point sources or groundwater sources. Timing of TN and TP concentration increases compared to streamflow increases indicate that nitrogen and phosphorus loads are more strongly related to streamflow than to a particular period of the year, indicating that runoff, within-bank nutrients that are suspended during higher streamflows, or both are a substantial source of nutrients regardless of timing.

A quantitative assessment of the contributions of climatic indicators to changes in nutrients and oxygen levels in a shallow reservoir in China

NASA Astrophysics Data System (ADS)

Zhang, Chen; Zhang, Wenna; Liu, Hanan; Gao, Xueping; Huang, Yixuan

2017-06-01

Climate change has an indirect effect on water quality in freshwater ecosystems, but it is difficult to assess the contribution of climate change to the complex system. This study explored to what extent climatic indicators (air temperature, wind speed, and rainfall) influence nutrients and oxygen levels in a shallow reservoir, Yuqiao Reservoir, China. The study comprises three parts—describing the temporal trends of climatic indicators and water quality parameters during the period 1992-2011, analyzing the potential impacts of climate on water quality, and finally developing a quantitative assessment to evaluate how climatic factors govern nutrient levels in the reservoir. Our analyses showed that the reservoir experienced substantial cold periods (1992-2001) followed by a warm period (2002-2011). The results showed that increasing air temperature in spring, autumn, and winter and increasing annual wind speed decrease total phosphorus (TP) concentration in the reservoir in spring, summer, and winter. According to the quantitative assessment, the increase in air temperature in spring and winter had a larger contribution to the decrease in TP concentration (47.2 and 64.1%), compared with the influence from decreased wind speed and rainfall. The field data suggest that nutrients decline due to enhanced uptake by macrophytes in years when spring was warmer and the macrophytes started to grow earlier in the season. The increasing wind speed and air temperature in spring also significantly contribute to the increase in dissolved oxygen concentration. This study helps managers to foresee how potential future climate change might influence water quality in similar lake ecosystems.

Estimations of daily energy and nutrient availability based on nationally representative household budget survey data. The Data Food Networking (DAFNE) project.

PubMed

Naska, A; Oikonomou, E; Trichopoulou, A; Wagner, K; Gedrich, K

2007-12-01

To describe a cost-efficient method for estimating energy and nutrient availability using household budget survey (HBS) data. Four different approaches were tested and the results were compared with published nutrient intake data. The selected method was exemplarily applied in German and Greek data. Germany, 1998; Greece, 1998/99. Nationally representative HBSs. Comparisons showed that HBS-based estimates were generally close to intake data when results were presented as contributions to daily energy intake. Daily energy and protein availabilities were similar in Germany and Greece. Differences were observed in the availability of carbohydrates (German households reported a 5 percentage points higher contribution to daily energy availability) and lipids (Greek households recorded higher values for total fat, but lower values for saturated fat). Meat, added lipids and potatoes were important energy suppliers in Germany, whereas in Greece the first three energy suppliers were added lipids, cereals and meat. In both countries, meat, cereals, milk and cheese were important protein sources and cereals, potatoes, fruits and nuts contributed more than 60% of the daily carbohydrate availability. Added lipids were the major source of fat in the daily diet of both countries, but their contribution amounted to less than one-third in Germany and two-thirds in Greece. National HBS data can be used for monitoring and comparing nutrient availability among representative population samples of different countries. The ground is set for the development of a harmonised food composition table to be applied to HBS food data at international level.

Tourism Revenue as a Conservation Tool for Threatened Birds in Protected Areas

PubMed Central

Steven, Rochelle; Castley, J. Guy; Buckley, Ralf

2013-01-01

Many bird populations worldwide are at risk of extinction, and rely heavily on protected area networks for their continued conservation. Tourism to these areas contributes to conservation by generating revenue for management. Here we quantify the contribution of tourism revenue for bird species in the IUCN Red List, using a simple accounting method. Relevant data are available for 90 (16%) of the 562 critically endangered and endangered species. Contributions of tourism to bird conservation are highest, 10–64%, in South America, Africa, and their neighbouring islands. Critically endangered bird species rely on tourism more heavily than endangered species (p<0.02). Many protected areas could also enhance their management budgets by promoting birdwatching tourism specifically. PMID:23667498

Quantifying the relative contribution of an ecological reserve to conservation objectives

USGS Publications Warehouse

Aagaard, Kevin; Lyons, James E.; Thogmartin, Wayne E.

2017-01-01

Evaluating the role public lands play in meeting conservation goals is an essential step in good governance. We present a tool for comparing the regional contribution of each of a suite of wildlife management units to conservation goals. We use weighted summation (simple additive weighting) to compute a Unit Contribution Index (UCI) based on species richness, population abundance, and a conservation score based on IUCN Red List classified threat levels. We evaluate UCI for a subset of the 729 participating wetlands of the Integrated Waterbird Management and Monitoring (IWMM) Program across U.S. Fish and Wildlife Service Regions 3 (Midwest USA), 4 (Southeast USA), and 5 (Northeast USA). We found that the median across-Region UCI for Region 5 was greater than Regions 3 and 4, while Region 4 had the greatest within-Region UCI median. This index is a powerful tool for wildlife managers to evaluate the performance of units within the conservation estate.

Interactions between plant nutrients, water and carbon dioxide as factors limiting crop yields

PubMed Central

Gregory, P. J.; Simmonds, L. P.; Warren, G. P.

1997-01-01

Biomass production of annual crops is often directly proportional to the amounts of radiation intercepted, water transpired and nutrients taken up. In many places the amount of rainfall during the period of rapid crop growth is less than the potential rate of evaporation, so that depletion of stored soil water is commonplace. The rate of mineralization of nitrogen (N) from organic matter and the processes of nutrient loss are closely related to the availability of soil water. Results from Kenya indicate the rapid changes in nitrate availability following rain.
Nutrient supply has a large effect on the quantity of radiation intercepted and hence, biomass production. There is considerable scope for encouraging canopy expansion to conserve water by reducing evaporation from the soil surface in environments where it is frequently rewetted, and where the unsaturated hydraulic conductivity of the soil is sufficient to supply water at the energy limited rate (e.g. northern Syria). In regions with high evaporative demand and coarse-textured soils (e.g. Niger), transpiration may be increased by management techniques that reduce drainage.
Increases in atmospheric [CO2] are likely to have only a small impact on crop yields when allowance is made for the interacting effects of temperature, and water and nutrient supply.

Nutrient adequacy and diet quality in low-income Hispanic Children – The VIVA LA FAMILIA Study

USDA-ARS?s Scientific Manuscript database

The role of nutrient adequacy and diet quality in the etiology of childhood obesity is poorly understood. Epidemiological studies have suggested that low-cost, energy dense diets high in grains, added sugars, and fat contribute to the development of obesity, especially in low-income groups. The spec...

RARE Grant- Atmospheric Dry Deposition: Quantification of Mercury and Nutrients using Novel Surrogate Surface Collector Techniques

EPA Science Inventory

This study will quantify the daily surrogate surface dry deposition of mercury and nutrient species, and evaluate its relative importance to wet deposition at two sites in Florida over a two-year period. It will identify the major sources contributing to the observed mercury and...

Growth and nutrient content of herbaceous seedlings associated with biological soil crusts

Treesearch

R. L. Pendleton; B. K. Pendleton; G. L. Howard; S. D. Warren

2003-01-01

Biological soil crusts of arid and semiarid lands contribute significantly to ecosystem stability by means of soil stabilization, nitrogen fixation, and improved growth and establishment of vascular plant species. In this study, we examined growth and nutrient content of Bromus tectorum, Elymus elymoides, Gaillardia pulchella, and Sphaeralcea munroana grown in soil...

Path analyses of grain P, Zn, Cu, Fe, and Ni in a biosolids-amended dryland wheat agroecosystem

USDA-ARS?s Scientific Manuscript database

Biosolids land application is an effective means of recycling plant nutrients and is the preferred method of biosolids reuse by the US Environmental Protection Agency. One issue concerning biosolids application is the extent of the contribution of biosolids-borne plant nutrients to the overall crop...

Glucagon-like peptide 2 therapy reduces the negative impacts the proinflammatory response in the gut of calves with coccidiosis

USDA-ARS?s Scientific Manuscript database

Damage to the intestinal epithelium reduces nutrient absorption and animal growth, and can have negative long-term health effects on livestock. The intestinotropic hormone glucagon-like peptide 2 (GLP-2) contributes to gut integrity, reduces inflammation, and improves nutrient absorption. The presen...

Recipe standardization, nutrient composition and sensory evaluation of waterleaf (Talinum triangulare) and wild spinach (Gnetum africanum) soup "afang" commonly consumed in South-south Nigeria.

PubMed

Alozie, Yetunde E; Ene-Obong, Henrietta N

2018-01-01

One hundred recipes of waterleaf and wild spinach soup (afang) consumed among the Ibibios in South-south Nigeria were collected through interview and questionnaire from indigenous homemakers and food sellers, harmonized, standardized, prepared and their nutrient content calculated. Mean weights of ingredients were calculated to obtain the control recipe. Major ingredients in the soup were analyzed chemically. Edible portions, retention factors to be applied in recipe calculation were determined. Sensory evaluation was conducted on five of the most preferred recipes on a nine-point hedonic scale. Edible coefficients of major foods ranged between 0.32 and 0.95. Significant changes (p<0.05) in nutrients were observed between raw and cooked ingredients and recipes. Afang soup had 67.9% moisture; protein, 12.7% and energy, 169kcal. Fat contributed 57% of the total energy. Consumption of adequate quantities of afang soup will contribute substantially to Recommended Nutrient Intake of protein and micronutrients which will further increase with additional fish/meat. Copyright © 2016 Elsevier Ltd. All rights reserved.

Loads of nitrate, phosphorus, and total suspended solids from Indiana watersheds

USGS Publications Warehouse

Bunch, Aubrey R.

2016-01-01

Transport of excess nutrients and total suspended solids (TSS) such as sediment by freshwater systems has led to degradation of aquatic ecosystems around the world. Nutrient and TSS loads from Midwestern states to the Mississippi River are a major contributor to the Gulf of Mexico Hypoxic Zone, an area of very low dissolved oxygen concentration in the Gulf of Mexico. To better understand Indiana’s contribution of nutrients and TSS to the Mississippi River, annual loads of nitrate plus nitrite as nitrogen, total phosphorus, and TSS were calculated for nine selected watersheds in Indiana using the load estimation model, S-LOADEST. Discrete water-quality samples collected monthly by the Indiana Department of Environmental Management’s Fixed Stations Monitoring Program from 2000–2010 and concurrent discharge data from the U. S. Geological Survey streamflow gages were used to create load models. Annual nutrient and TSS loads varied across Indiana by watershed and hydrologic condition. Understanding the loads from large river sites in Indiana is important for assessing contributions of nutrients and TSS to the Mississippi River Basin and in determining the effectiveness of best management practices in the state. Additionally, evaluation of loads from smaller upstream watersheds is important to characterize improvements at the local level and to identify priorities for reduction.

Nutrient Retention in Restored Streams and Floodplains: A ...

EPA Pesticide Factsheets

Abstract: Excess nitrogen (N) and phosphorus (P) from human activities have contributed to degradation of coastal waters globally. A growing body of work suggests that hydrologically restoring streams and floodplains in agricultural and urban watersheds has potential to increase nitrogen and phosphorus retention, but rates and mechanisms have not yet been synthesized and compared across studies. We conducted a review of nutrient retention within hydrologically reconnected streams and floodplains including 79 studies. Overall, 62% of results were positive, 26% were neutral, and 12% were negative. The studies we reviewed used a variety of methods to analyze nutrients cycling. We did a further intensive meta-analysis on nutrient spiraling studies because this method was the most consistent and comparable between studies. A meta-analysis of 240 experimental additions of ammonium (NH4+), nitrate (NO3-), and soluble reactive phosphorus (SRP) was synthesized from 15 nutrient spiraling studies. Overall, we found that rates of uptake were variable along stream reaches over space and time. Our results indicate that the size of the stream restoration (total surface area) and hydrologic residence time can be key drivers in influencing N and P uptake at broader watershed scales or along the urban watershed continuum. Excess nitrogen and phosphorus from human activities contributes to the degradation of water quality in streams and coastal areas nationally and globally.

Effects of burn temperature on ash nutrient forms and availability from cattail (Typha domingensis) and sawgrass (Cladium jamaicense) in the Florida Everglades.

PubMed

Qian, Y; Miao, S L; Gu, B; Li, Y C

2009-01-01

Plant ash derived from fire plays an important role in nutrient balance and cycling in ecosystems. Factors that determine the composition and availability of ash nutrients include fire intensity (burn temperature and duration), plant species, habitat nutrient enrichment, and leaf type (live or dead leaf). We used laboratory simulation methods to evaluate temperature effects on nutrient composition and metals in the residual ash of sawgrass (Cladium jamaicense) and cattail (Typha domingensis), particularly on post-fire phosphorus (P) availability in plant ash. Live and dead leaf samples were collected from Water Conservation Area 2A in the northern Everglades along a soil P gradient, where prescribed fire may be used to accelerate recovery of this unique ecosystem. Significant decreases in total carbon and total nitrogen were detected with increasing fire temperature. Organic matter combustion was nearly complete at temperatures > or = 450 degrees C. HCl-extractable P (average, 50% of total P in the ash) and NH(4)Cl-extractable P (average, 33% of total P in the ash) were the predominant P fractions for laboratory-burned ash. Although a low-intensity fire could induce an elevation of P availability, an intense fire generally resulted in decreased water-soluble P. Significant differences in nutrient compositions were observed between species, habitat nutrient status, and leaf types. More labile inorganic P remained in sawgrass ash than in cattail ash; hence, sawgrass ash has a greater potential to release available P than cattail. Fire intensity affected plant ash nutrient composition, particularly P availability, and the effects varied with plant species and leaf type. Therefore, it is important to consider fire intensity and vegetation community when using a prescribed fire for ecosystem management.

Controls on foliar nutrient and aluminium concentrations in a tropical tree flora: phylogeny, soil chemistry and interactions among elements.

PubMed

Metali, Faizah; Abu Salim, Kamariah; Tennakoon, Kushan; Burslem, David F R P

2015-01-01

Foliar elemental concentrations are predictors of life-history variation and contribute to spatial patterns in biogeochemical cycling. We examined the contributions of habitat association, local soil environment, and elemental interactions to variation in foliar elemental concentrations in tropical trees using methods that account for phylogeny. We sampled top-soils and leaves of 58 tropical trees in heath forest (HF) on nutrient-poor sand and mixed dipterocarp forest (MDF) on nutrient-rich clay soils. A phylogenetic generalized least squares method was used to determine how foliar nutrient and aluminium (Al) concentrations varied in response to habitat distribution, soil chemistry and other elemental concentrations. Foliar nitrogen (N) and Al concentrations were greater for specialists of MDF than for specialists of HF, while foliar calcium (Ca) concentrations showed the opposite trend. Foliar magnesium (Mg) concentrations were lower for generalists than for MDF specialists. Foliar element concentrations were correlated with fine-scale variation in soil chemistry in phylogenetically controlled analyses across species, but there was limited within-species plasticity in foliar elemental concentrations. Among Al accumulators, foliar Al concentration was positively associated with foliar Ca and Mg concentrations, and negatively associated with foliar phosphorus (P) concentrations. The Al-accumulation trait and relationships between foliar elemental and Al concentrations may contribute to species habitat partitioning and ecosystem-level differences in biogeochemical cycles. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

Nutrient and sediment concentrations and loads in the Steele Bayou Basin, northwestern Mississippi, 2010–14

USGS Publications Warehouse

Hicks, Matthew B.; Murphy, Jennifer C.; Stocks, Shane J.

2017-06-01

The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers-Vicksburg District, monitored streamflow, water quality, and sediment at two stations on the Steele Bayou in northwestern Mississippi from October 2010 through September 2014 to characterize nutrient and sediment concentrations and loads in areas where substantial implementation of conservation efforts have been implemented. The motivation for this effort was to quantify improvements, or lack thereof, in water quality in the Steele Bayou watershed as a result of implementing large- and small-scale best-management practices aimed at reducing nutrient and sediment concentrations and loads. The results of this study document the hydrologic, water-quality, and sedimentation status of these basins following over two decades of ongoing implementation of conservation practices.Results from this study indicate the two Steele Bayou stations have comparable loads and yields of total nitrogen, phosphorus, and suspended sediment when compared to other agricultural basins in the southeastern and central United States. However, nitrate plus nitrite yields from basins in the Mississippi River alluvial plain, including the Steele Bayou Basin, are generally lower than other agricultural basins in the southeastern and central United States.Seasonal variation in nutrient and sediment loads was observed at both stations and for most constituents. About 50 percent of the total annual nutrient and sediment load was observed during the spring (February through May) and between 25 and 50 percent was observed during late fall and winter (October through January). These seasonal patterns probably reflect a combination of seasonal patterns in precipitation, runoff, streamflow, and in the timing of fertilizer application.Median concentrations of total nitrogen, nitrate plus nitrite, total phosphorus, orthophosphate, and suspended sediment were slightly higher at the upstream station, Steele Bayou near Glen Allan, than at the downstream station, Steele Bayou at Grace Road at Hopedale, MS, although the differences typically were not statistically significant. Mean annual loads of nitrate plus nitrite and suspended sediment were also larger at the upstream station, although the annual loads at both stations were generally within the 95-percent confidence intervals of each other.

Nutrient and Rainfall Additions Shift Phylogenetically Estimated Traits of Soil Microbial Communities.

PubMed

Gravuer, Kelly; Eskelinen, Anu

2017-01-01

Microbial traits related to ecological responses and functions could provide a common currency facilitating synthesis and prediction; however, such traits are difficult to measure directly for all taxa in environmental samples. Past efforts to estimate trait values based on phylogenetic relationships have not always distinguished between traits with high and low phylogenetic conservatism, limiting reliability, especially in poorly known environments, such as soil. Using updated reference trees and phylogenetic relationships, we estimated two phylogenetically conserved traits hypothesized to be ecologically important from DNA sequences of the 16S rRNA gene from soil bacterial and archaeal communities. We sampled these communities from an environmental change experiment in California grassland applying factorial addition of late-season precipitation and soil nutrients to multiple soil types for 3 years prior to sampling. Estimated traits were rRNA gene copy number, which contributes to how rapidly a microbe can respond to an increase in resources and may be related to its maximum growth rate, and genome size, which suggests the breadth of environmental and substrate conditions in which a microbe can thrive. Nutrient addition increased community-weighted mean estimated rRNA gene copy number and marginally increased estimated genome size, whereas precipitation addition decreased these community means for both estimated traits. The effects of both treatments on both traits were associated with soil properties, such as ammonium, available phosphorus, and pH. Estimated trait responses within several phyla were opposite to the community mean response, indicating that microbial responses, although largely consistent among soil types, were not uniform across the tree of life. Our results show that phylogenetic estimation of microbial traits can provide insight into how microbial ecological strategies interact with environmental changes. The method could easily be applied to any of the thousands of existing 16S rRNA sequence data sets and offers potential to improve our understanding of how microbial communities mediate ecosystem function responses to global changes.

The Nitrate App: Enhancing nutrient best management practice adoption and targeting via instantaneous, on-farm nitrate data

NASA Astrophysics Data System (ADS)

Rozemeijer, J.; De Geus, D.; Ekkelenkamp, R.

2016-12-01

Sociological surveys suggest that farmers understand that agriculture contributes to nutrient pollution but the same surveys also indicate that in the absence of on-farm nitrate data, farmers assume someone else is causing the problem. This tendency to overestimate our own abilities is common to all of us and often described as "Lake Wobegon Syndrome" after the mythical town where "where all the women are strong, all the men are good-looking, and all the children are above average." We developed the Nitrate App for smartphones to enable farmers and citizens to collect and share nitrate concentration measurements. The app accurately reads and interprets nitrate test strips, directly displays the measured concentration, and gives the option to share the result. The shared results are immediately visualised in the online Delta Data Viewer. Within this viewer, user group specific combinations of background maps, monitoring data, and study area characteristics can be configured. Through the Nitrate App's mapping function project managers can more accurately target conservation practices to areas with the highest nitrate concentrations and loads. Furthermore, we expect that the actual on-farm data helps to overcome the "Lake Wobegon Effect" and will encourage farmers to talk to specialists about the right nutrient best management practices (BMP's) for their farm. After implementing these BMP's, the farmers can keep monitoring to evaluate the reduction in nitrate losses. In this presentation, we explain the Nitrate App technology and present the results of the first field applications in The Netherlands. We expect this free to download app to have wide transferability across watershed projects worldwide focusing on nitrate contamination of groundwater or surface water. Its simple design requires no special equipment outside of the nitrate test strips, a reference card, and a smartphone. The technology is also transferable to other relevant solutes for which test strips are available, like ammonium, phosphate, sulphate, chloride, and pH.

TIF-IA-dependent regulation of ribosome synthesis in drosophila muscle is required to maintain systemic insulin signaling and larval growth.

PubMed

Ghosh, Abhishek; Rideout, Elizabeth J; Grewal, Savraj S

2014-10-01

The conserved TOR kinase signaling network links nutrient availability to cell, tissue and body growth in animals. One important growth-regulatory target of TOR signaling is ribosome biogenesis. Studies in yeast and mammalian cell culture have described how TOR controls rRNA synthesis-a limiting step in ribosome biogenesis-via the RNA Polymerase I transcription factor TIF-IA. However, the contribution of TOR-dependent ribosome synthesis to tissue and body growth in animals is less clear. Here we show in Drosophila larvae that ribosome synthesis in muscle is required non-autonomously to maintain normal body growth and development. We find that amino acid starvation and TOR inhibition lead to reduced levels of TIF-IA, and decreased rRNA synthesis in larval muscle. When we mimic this decrease in muscle ribosome synthesis using RNAi-mediated knockdown of TIF-IA, we observe delayed larval development and reduced body growth. This reduction in growth is caused by lowered systemic insulin signaling via two endocrine responses: reduced expression of Drosophila insulin-like peptides (dILPs) from the brain and increased expression of Imp-L2-a secreted factor that binds and inhibits dILP activity-from muscle. We also observed that maintaining TIF-IA levels in muscle could partially reverse the starvation-mediated suppression of systemic insulin signaling. Finally, we show that activation of TOR specifically in muscle can increase overall body size and this effect requires TIF-IA function. These data suggest that muscle ribosome synthesis functions as a nutrient-dependent checkpoint for overall body growth: in nutrient rich conditions, TOR is required to maintain levels of TIF-IA and ribosome synthesis to promote high levels of systemic insulin, but under conditions of starvation stress, reduced muscle ribosome synthesis triggers an endocrine response that limits systemic insulin signaling to restrict growth and maintain homeostasis.

TIF-IA-Dependent Regulation of Ribosome Synthesis in Drosophila Muscle Is Required to Maintain Systemic Insulin Signaling and Larval Growth

PubMed Central

Ghosh, Abhishek; Rideout, Elizabeth J.; Grewal, Savraj S.

2014-01-01

The conserved TOR kinase signaling network links nutrient availability to cell, tissue and body growth in animals. One important growth-regulatory target of TOR signaling is ribosome biogenesis. Studies in yeast and mammalian cell culture have described how TOR controls rRNA synthesis—a limiting step in ribosome biogenesis—via the RNA Polymerase I transcription factor TIF-IA. However, the contribution of TOR-dependent ribosome synthesis to tissue and body growth in animals is less clear. Here we show in Drosophila larvae that ribosome synthesis in muscle is required non-autonomously to maintain normal body growth and development. We find that amino acid starvation and TOR inhibition lead to reduced levels of TIF-IA, and decreased rRNA synthesis in larval muscle. When we mimic this decrease in muscle ribosome synthesis using RNAi-mediated knockdown of TIF-IA, we observe delayed larval development and reduced body growth. This reduction in growth is caused by lowered systemic insulin signaling via two endocrine responses: reduced expression of Drosophila insulin-like peptides (dILPs) from the brain and increased expression of Imp-L2—a secreted factor that binds and inhibits dILP activity—from muscle. We also observed that maintaining TIF-IA levels in muscle could partially reverse the starvation-mediated suppression of systemic insulin signaling. Finally, we show that activation of TOR specifically in muscle can increase overall body size and this effect requires TIF-IA function. These data suggest that muscle ribosome synthesis functions as a nutrient-dependent checkpoint for overall body growth: in nutrient rich conditions, TOR is required to maintain levels of TIF-IA and ribosome synthesis to promote high levels of systemic insulin, but under conditions of starvation stress, reduced muscle ribosome synthesis triggers an endocrine response that limits systemic insulin signaling to restrict growth and maintain homeostasis. PMID:25356674

Emiliania huxleyi endures N-limitation with an efficient metabolic budgeting and effective ATP synthesis.

PubMed

Rokitta, Sebastian D; Von Dassow, Peter; Rost, Björn; John, Uwe

2014-12-02

Global change will affect patterns of nutrient upwelling in marine environments, potentially becoming even stricter regulators of phytoplankton primary productivity. To better understand phytoplankton nutrient utilization on the subcellular basis, we assessed the transcriptomic responses of the life-cycle stages of the biogeochemically important microalgae Emiliania huxleyi to nitrogen-limitation. Cells grown in batch cultures were harvested at 'early' and 'full' nitrogen-limitation and were compared with non-limited cells. We applied microarray-based transcriptome profilings, covering ~10.000 known E. huxleyi gene models, and screened for expression patterns that indicate the subcellular responses. The diploid life-cycle stage scavenges nitrogen from external organic sources and -like diatoms- uses the ornithine-urea cycle to rapidly turn over cellular nitrogen. The haploid stage reacts similarly, although nitrogen scavenging is less pronounced and lipid oxidation is more prominent. Generally, polyamines and proline appear to constitute major organic pools that back up cellular nitrogen. Both stages induce a malate:quinone-oxidoreductase that efficiently feeds electrons into the respiratory chain and drives ATP generation with reduced respiratory carbon throughput. The use of the ornithine-urea cycle to budget the cellular nitrogen in situations of limitation resembles the responses observed earlier in diatoms. This suggests that underlying biochemical mechanisms are conserved among distant clades of marine phototrophic protists. The ornithine-urea cycle and proline oxidation appear to constitute a sensory-regulatory system that monitors and controls cellular nitrogen budgets under limitation. The similarity between the responses of the life-cycle stages, despite the usage of different genes, also indicates a strong functional consistency in the responses to nitrogen-limitation that appears to be owed to biochemical requirements. The malate:quinone-oxidoreductase is a genomic feature that appears to be absent from diatom genomes, and it is likely to strongly contribute to the uniquely high endurance of E. huxleyi under nutrient limitation.

Profiling contents of water-soluble metabolites and mineral nutrients to evaluate the effects of pesticides and organic and chemical fertilizers on tomato fruit quality.

PubMed

Watanabe, Masami; Ohta, Yuko; Licang, Sun; Motoyama, Naoki; Kikuchi, Jun

2015-02-15

In this study, the contents of water-soluble metabolites and mineral nutrients were measured in tomatoes cultured using organic and chemical fertilizers, with or without pesticides. Mineral nutrients and water-soluble metabolites were determined by inductively coupled plasma-atomic emission spectrometry and (1)H nuclear magnetic resonance spectrometry, respectively, and results were analysed by principal components analysis (PCA). The mineral nutrient and water-soluble metabolite profiles differed between organic and chemical fertilizer applications, which accounted for 88.0% and 55.4%, respectively, of the variation. (1)H-(13)C-hetero-nuclear single quantum coherence experiments identified aliphatic protons that contributed to the discrimination of PCA. Pesticide application had little effect on mineral nutrient content (except Fe and P), but affected the correlation between mineral nutrients and metabolites. Differences in the content of mineral nutrients and water-soluble metabolites resulting from different fertilizer and pesticide applications probably affect tomato quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

The relationship between transpiration and nutrient uptake in wheat changes under elevated atmospheric CO2.

PubMed

Houshmandfar, Alireza; Fitzgerald, Glenn J; O'Leary, Garry; Tausz-Posch, Sabine; Fletcher, Andrew; Tausz, Michael

2017-12-04

The impact of elevated [CO 2 ] (e[CO 2 ]) on crops often includes a decrease in their nutrient concentrations where reduced transpiration-driven mass flow of nutrients has been suggested to play a role. We used two independent approaches, a free-air CO 2 enrichment (FACE) experiment in the South Eastern wheat belt of Australia and a simulation study employing the agricultural production systems simulator (APSIM), to show that transpiration (mm) and nutrient uptake (g m -2 ) of nitrogen (N), potassium (K), sulfur (S), calcium (Ca), magnesium (Mg) and manganese (Mn) in wheat are correlated under e[CO 2 ], but that nutrient uptake per unit water transpired is higher under e[CO 2 ] than under ambient [CO 2 ] (a[CO 2 ]). This result suggests that transpiration-driven mass flow of nutrients contributes to decreases in nutrient concentrations under e[CO 2 ], but cannot solely explain the overall decline. © 2017 Scandinavian Plant Physiology Society.

Approaches for evaluating the effects of bivalve filter feeding on nutrient dynamics in Puget Sound, Washington

USGS Publications Warehouse

Konrad, Christopher P.

2014-01-01

Marine bivalves such as clams, mussels, and oysters are an important component of the food web, which influence nutrient dynamics and water quality in many estuaries. The role of bivalves in nutrient dynamics and, particularly, the contribution of commercial shellfish activities, are not well understood in Puget Sound, Washington. Numerous approaches have been used in other estuaries to quantify the effects of bivalves on nutrient dynamics, ranging from simple nutrient budgeting to sophisticated numerical models that account for tidal circulation, bioenergetic fluxes through food webs, and biochemical transformations in the water column and sediment. For nutrient management in Puget Sound, it might be possible to integrate basic biophysical indicators (residence time, phytoplankton growth rates, and clearance rates of filter feeders) as a screening tool to identify places where nutrient dynamics and water quality are likely to be sensitive to shellfish density and, then, apply more sophisticated methods involving in-situ measurements and simulation models to quantify those dynamics.

Autophagy: not good OR bad, but good AND bad.

PubMed

Altman, Brian J; Rathmell, Jeffrey C

2009-05-01

Autophagy is a well-established mechanism to degrade intracellular components and provide a nutrient source to promote survival of cells in metabolic distress. Such stress can be caused by a lack of available nutrients or by insufficient rates of nutrient uptake. Indeed, growth factor deprivation leads to internalization and degradation of nutrient transporters, leaving cells with limited means to access extracellular nutrients even when plentiful.This loss of growth factor signaling and extracellular nutrients ultimately leads to apoptosis, but also activates autophagy, which may degrade intracellular components and provide fuel for mitochondrial bioenergetics. The precise metabolic role of autophagy and how it intersects with the apoptotic pathways in growth factor withdrawal, however, has been uncertain. Our recent findings ingrowth factor-deprived hematopoietic cells show that autophagy can simultaneously contribute to cell metabolism and initiate a pathway to sensitize cells to apoptotic death. This pathway may promote tissue homeostasis by ensuring that only cells with high resistance to apoptosis may utilize autophagy as a survival mechanism when growth factors are limiting and nutrient uptake decreases.

Epiphyte loads on seagrasses and microphytobenthos abundance are not reliable indicators of nutrient availability in oligotrophic coastal ecosystems.

PubMed

Fourqurean, James W; Muth, Meredith F; Boyer, Joseph N

2010-07-01

Despite marked gradients in nutrient availability that control the abundance and species composition of seagrasses in south Florida, and the importance of nutrient availability in controlling abundance and composition of epiphytes on seagrasses in other locations, we did not find that epiphyte load on the dominant seagrass, Thalassia testudinum, or that the relative contribution of algal epiphytes to the epiphyte community, was positively correlated with nutrient availability in the water column or the sediment in oligotrophic seagrass beds. Further, the abundance of microphytobenthos, as indicated by Chlorophyll-a concentration in the sediments, was not directly correlated with concentrations of nutrients in the sediments. Our results suggest that epiphyte and microphytobenthos abundance are not unambiguous indicators of nutrient availability in relatively pristine seagrass environments, and therefore would make poor candidates for indicators of the status and trends of seagrass ecosystems in relatively low-nutrient environments like the Florida Keys. Copyright 2010 Elsevier Ltd. All rights reserved.

Reducing nitrogen export from the corn belt to the Gulf of Mexico: Agricultural strategies for remediating hypoxia

USDA-ARS?s Scientific Manuscript database

We used the SPARROW model for the Upper Mississippi River Basin to evaluate the potential water quality benefits (nutrient load reductions) likely to be achieved by a variety of agricultural conservation practices in the Upper Mississippi-Ohio River system, and to compare these to the 45% nitrogen l...

Chesapeake Bay Riparian Handbook: A Guide for Establishing and Maintaining Riparian Forest Buffers

Treesearch

Roxane Palone; Albert Todd

1998-01-01

The Purpose of This Handbook Riparian forest buffers have been identified as avaluable nutrient reduction tool when used inconjunction with other conservation practices. For this reason, the Chesapeake Bay Programhas targeted riparian forests as a key habitat for restoration. The purpose of this handbook is toprovide professional land managers and plan-ners with the...

Relating nutrient and herbicide fate with landscape features and characteristics of 15 subwatersheds in the Choptank River Watershed

USDA-ARS?s Scientific Manuscript database

The Choptank River is an estuary and tributary on the eastern shore of the Chesapeake Bay; it drains portions of the Delmarva Peninsula, located within the Mid-Atlantic region of the United States. Its watershed is an ARS Benchmark Watershed in the Conservation Effects Assessment Project (CEAP). M...

Reconciling fisheries with conservation in watersheds: tools for informed decisions.

Treesearch

Peter A. Bisson; Timothy J. Beechie; George R. Pess

2007-01-01

Watersheds capture and deliver fresh water to streams, rivers, wetlands and lakes. They are fundamental landscape units for freshwater fisheries because they govern the characteristics of the annual hydrograph, the configuration and physical features of stream channels, and the input of organic matter and nutrients. Watersheds are also where we live, grow crops, and...

Water quality assessment of the San Joaquin--Tulare basins, California; analysis of available data on nutrients and suspended sediment in surface water, 1972-1990

USGS Publications Warehouse

Kratzer, Charles R.; Shelton, Jennifer L.

1998-01-01

Nutrients and suspended sediment in surface water of the San Joaquin-Tulare basins in California were assessed using 1972-1990 data from the U.S. Geological Survey's National Water Information System and the U.S. Environmental Protection Agency's STOrage and RETrieval database. Loads of nutrients and suspended sediment were calculated at several sites and the contributions from point and nonpoint sources were estimated. Trends in nutrient and suspended-sediment concentrations were evaluated at several sites, especially at the basin outlet on the San Joaquin River. Comparisons of nutrient and suspended sediment concentrations were made among three environmental settings: the San Joaquin Valley--west side, the San Joaquin Valley--east side, and the Sierra Nevada.

Motivational functionalism and urban conservation stewardship: implications for volunteer involvement

Treesearch

Stanley T. Asah; Dale J. Blahna

2012-01-01

Conservation in urban areas faces growing financial challenges and inadequate stakeholder involvement. Conservation psychology can mitigate these challenges in many ways. One way is through conservation volunteerism, if we attend to and capitalize on volunteers' motivations. Conservation volunteerism significantly contributes to ecological knowledge acquisition,...

The vertical distribution of nutrients and oxygen 18 in the upper Arctic Ocean

NASA Astrophysics Data System (ADS)

BjöRk, GöRan

1990-09-01

The observed vertical nutrient distribution including a maximum at about 100 m depth in the Arctic Ocean is investigated using a one-dimensional time-dependent circulation model together with a simple biological model. The circulation model includes a shelf-forced circulation. This is thought to take place in a box from which the outflow is specified regarding temperature and volume flux at different salinities. It has earlier been shown that the circulation model is able to reproduce the observed mean salinity and temperature stratification in the Arctic Ocean. Before introducing nutrients in the model a test is performed using the conservative tracer δ18 (18O/16O ratio) as one extra state variable in order to verify the circulation model. It is shown that the field measurements can be simulated. The result is, however, rather sensitive to the tracer concentration in the Bering Strait inflow. The nutrients nitrate, phosphate, and silicate are then treated by coupling a simple biological model to the circulation model. The biological model describes some overall effects of production, sinking, and decomposition of organic matter. First a standard case of the biological model is presented. This is followed by some modified cases. It is shown that the observed nutrient distribution including the maximum can be generated. The available nutrient data from the Arctic Ocean are not sufficient to decide which among the cases is the most likely to occur. One case is, however, chosen as the best case. A nutrient budget and estimates of the magnitudes of the new production are presented for this case.

Modeling of the Bacillus subtilis Bacterial Biofilm Growing on an Agar Substrate

PubMed Central

Wang, Xiaoling; Wang, Guoqing; Hao, Mudong

2015-01-01

Bacterial biofilms are organized communities composed of millions of microorganisms that accumulate on almost any kinds of surfaces. In this paper, a biofilm growth model on an agar substrate is developed based on mass conservation principles, Fick's first law, and Monod's kinetic reaction, by considering nutrient diffusion between biofilm and agar substrate. Our results show biofilm growth evolution characteristics such as biofilm thickness, active biomass, and nutrient concentration in the agar substrate. We quantitatively obtain biofilm growth dependence on different parameters. We provide an alternative mathematical method to describe other kinds of biofilm growth such as multiple bacterial species biofilm and also biofilm growth on various complex substrates. PMID:26355542

Modeling of the Bacillus subtilis Bacterial Biofilm Growing on an Agar Substrate.

PubMed

Wang, Xiaoling; Wang, Guoqing; Hao, Mudong

2015-01-01

Bacterial biofilms are organized communities composed of millions of microorganisms that accumulate on almost any kinds of surfaces. In this paper, a biofilm growth model on an agar substrate is developed based on mass conservation principles, Fick's first law, and Monod's kinetic reaction, by considering nutrient diffusion between biofilm and agar substrate. Our results show biofilm growth evolution characteristics such as biofilm thickness, active biomass, and nutrient concentration in the agar substrate. We quantitatively obtain biofilm growth dependence on different parameters. We provide an alternative mathematical method to describe other kinds of biofilm growth such as multiple bacterial species biofilm and also biofilm growth on various complex substrates.

Greenland's glacial fjords and their role in regional biogeochemical dynamics.

NASA Astrophysics Data System (ADS)

Crosby, J.; Arndt, S.

2017-12-01

Greenland's coastal fjords serve as important pathways that connect the Greenland Ice Sheet (GrIS) and the surrounding oceans. They export seasonal glacial meltwater whilst being significant sites of primary production. These fjords are home to some of the most productive ecosystems in the world and possess high socio-economic value via fisheries. A growing number of studies have proposed the GrIS as an underappreciated yet significant source of nutrients to surrounding oceans. Acting as both transfer routes and sinks for glacial nutrient export, fjords have the potential to act as significant biogeochemical processors, yet remain underexplored. Critically, an understanding of the quantitative contribution of fjords to carbon and nutrient budgets is lacking, with large uncertainties associated with limited availability of field data and the lack of robust upscaling approaches. To close this knowledge gap we developed a coupled 2D physical-biogeochemical model of the Godthåbsfjord system, a sub-Arctic sill fjord in southwest Greenland, to quantitatively assess the impact of nutrients exported from the GrIS on fjord primary productivity and biogeochemical dynamics. Glacial meltwater is found to be a key driver of fjord-scale circulation patterns, whilst tracer simulations reveal the relative nutrient contributions from meltwater-driven upwelling and meltwater export from the GrIS. Hydrodynamic circulation patterns and freshwater transit times are explored to provide a first understanding of the glacier-fjord-ocean continuum, demonstrating the complex pattern of carbon and nutrient cycling at this critical land-ocean interface.

Dissolved Organic Carbon Degradation in Response to Nutrient Amendments in Southwest Greenland Lakes

NASA Astrophysics Data System (ADS)

Burpee, B. T.; Northington, R.; Simon, K. S.; Saros, J. E.

2014-12-01

Aquatic ecosystems across the Arctic are currently experiencing rapid shifts in biotic, chemical, and physical factors in response to climate change. Preliminary data from multiple lakes in southwestern Greenland indicate decreasing dissolved organic carbon (DOC) concentrations over the past decade. Though several factors may be contributing to this phenomenon, this study attempts to elucidate the potential of heterotrophic bacteria to degrade DOC in the presence of increasing nutrient concentrations. In certain Arctic regions, nutrient subsidies have been released into lakes due to permafrost thaw. If this is occurring in southwestern Greenland, we hypothesized that increased nutrient concentrations will relieve nutrient limitation, thereby allowing heterotrophic bacteria to utilize DOC as an energy source. This prediction was tested using experimental DOC degradation assays from four sample lakes. Four nutrient amendment treatments (control, N, P, and N + P) were used to simulate in situ subsidies. Five time points were sampled during the incubation: days 0, 3, 6, 14, and 60. Total organic carbon (TOC) and parallel factor (PARAFAC) analysis were used to monitor the relative concentrations of different DOC fractions over time. In addition, samples for extracellular enzyme activity (EEA) analysis were collected at every time point. Early analysis of fulvic and humic pools of DOC do not indicate any significant change from days 0 to 14. This could be due to the fact that these DOC fractions are relatively recalcitrant. This study will be important in determining whether bacterial degradation could be a contributing factor to DOC decline in arctic lakes.

Evidence of chronic anthropogenic nutrient within coastal lagoon reefs adjacent to urban and tourism centers, Kenya: A stable isotope approach.

PubMed

Mwaura, Jelvas; Umezawa, Yu; Nakamura, Takashi; Kamau, Joseph

2017-06-30

The source of anthropogenic nutrient and its spatial extent in three fringing reefs with differing human population gradients in Kenya were investigated using stable isotope approaches. Nutrient concentrations and nitrate-δ 15 N in seepage water indicated that population density and tourism contributed greatly to the extent of nutrient loading to adjacent reefs. Although water-column nutrient analyses did not show any significant difference among the reefs, higher δ 15 N and N contents in macrophytes showed terrestrial nutrients affected primary producers in onshore areas in Nyali and Bamburi reefs, but were mitigated by offshore water intrusion especially at Nyali. On the offshore reef flat, where the same species of macroalgae were not available, complementary use of δ 15 N in sedimentary organic matter suggested inputs of nutrients originated from the urban city of Mombasa. If population increases in the future, nutrient conditions in the shallower reef, Vipingo, may be dramatically degraded due to lower water exchange ratio. Copyright © 2017 Elsevier Ltd. All rights reserved.

High nutrient-use efficiency during early seedling growth in diverse Grevillea species (Proteaceae)

PubMed Central

He, Tianhua; Fowler, William M.; Causley, Casey L.

2015-01-01

Several hypotheses have been proposed to explain the rich floristic diversity in regions characterised by nutrient-impoverished soils; however, none of these hypotheses have been able to explain the rapid diversification over a relatively short evolutionary time period of Grevillea, an Australian plant genus with 452 recognised species/subspecies and only 11 million years of evolutionary history. Here, we hypothesise that the apparent evolutionary success of Grevillea might have been triggered by the highly efficient use of key nutrients. The nutrient content in the seeds and nutrient-use efficiency during early seedling growth of 12 species of Grevillea were compared with those of 24 species of Hakea, a closely related genus. Compared with Hakea, the Grevillea species achieved similar growth rates (root and shoot length) during the early stages of seedling growth but contained only approximately half of the seed nutrient content. We conclude that the high nutrient-use efficiency observed in Grevillea might have provided a selective advantage in nutrient-poor ecosystems during evolution and that this property likely contributed to the evolutionary success in Grevillea. PMID:26607493

The placenta. Not just a conduit for maternal fuels.

PubMed

Hay, W W

1991-12-01

The placenta is a specialized organ of exchange that provides nutrients to and excretes waste products from the fetus. The exchange of nutrients between placenta and fetus involves three major mechanisms: 1) direct transfer of nutrients from the maternal to the fetal plasma, 2) placental consumption of nutrients, and 3) placental conversion of nutrients to alternate substrate forms. Although direct transfer has been considered the primary means by which placental-fetal exchange controls the supply of nutrients to the fetus and thereby fetal metabolism and growth, the considerable metabolic activity of the placenta provides a large and fundamentally important contribution to both the quality and quantity of nutrient substrates supplied to the fetus; e.g., placental O2 and glucose consumption rates approach or even exceed those of brain and tumor tissue. Other placental metabolic activities include glycolysis, gluconeogenesis, glycogenesis, oxidation, protein synthesis, amino acid interconversion, triglyceride synthesis, and chain lengthening or shortening of individual fatty acids. Thus, consideration of the metabolism of the placenta is essential for a more complete understanding of how the placenta regulates nutrient transfer to the fetus, fetal energy balance, and fetal growth.

Suspended-sediment and nutrient loads for Waiakea and Alenaio Streams, Hilo, Hawaii, 2003-2006

USGS Publications Warehouse

Presley, Todd K.; Jamison, Marcael T.J.; Nishimoto, Dale C.

2008-01-01

Suspended sediment and nutrient samples were collected during wet-weather conditions at three sites on two ephemeral streams in the vicinity of Hilo, Hawaii during March 2004 to March 2006. Two sites were sampled on Waiakea Stream at 80- and 860-foot altitudes during March 2004 to August 2005. One site was sampled on Alenaio Stream at 10-foot altitude during November 2005 to March 2006. The sites were selected to represent different land uses and land covers in the area. Most of the drainage area above the upper Waiakea Stream site is conservation land. The drainage areas above the lower site on Waiakea Stream, and the site on Alenaio Stream, are a combination of conservation land, agriculture, rural, and urban land uses. In addition to the sampling, continuous-record streamflow sites were established at the three sampling sites, as well as an additional site on Alenaio Stream at altitude of 75 feet and 0.47 miles upstream from the sampling site. Stage was measured continuously at 15-minute intervals at these sites. Discharge, for any particular instant, or for selected periods of time, were computed based on a stage-discharge relation determined from individual discharge measurements. Continuous records of discharge were computed at the two sites on Waiakea Stream and the upper site on Aleniao Stream. Due to non-ideal hydraulic conditions within the channel of Alenaio Stream, a continuous record of discharge was not computed at the lower site on Alenaio Stream where samples were taken. Samples were analyzed for suspended sediment, and the nutrients total nitrogen, dissolved nitrite plus nitrate, and total phosphorus. Concentration data were converted to instantaneous load values: loads are the product of discharge and concentration, and are presented as tons per day for suspended sediment or pounds per day for nutrients. Daily-mean loads were computed by estimating concentrations relative to discharge using graphical constituent loading analysis techniques. Daily-mean loads were computed at the two Waiakea Stream sampling sites for the analyzed constituents, during the period October 1, 2003 to September 30, 2005. No record of daily-mean load was computed for the Alenaio Stream sampling site due to the problems with computing a discharge record. The maximum daily-mean loads for the upper site on Waiakea Stream for suspended sediment was 79 tons per day, and the maximum daily-mean loads for total nitrogen, dissolved nitrite plus nitrate, and total phosphorus were 1,350, 13, and 300 pounds per day, respectively. The maximum daily-mean loads for the lower site on Waiakea Stream for suspended sediment was 468 tons per day, and the maximum daily-mean loads for total nitrogen, nitrite plus nitrate, and total phosphorus were 913, 8.5, and 176 pounds per day, respectively. From the estimated continuous daily-mean load record, all of the maximum daily-mean loads occurred during October 2003 and September 2004, except for suspended sediment load for the lower site, which occurred on September 15, 2005. Maximum values were not all caused by a single storm event. Overall, the record of daily-mean loads showed lower loads during storm events for suspended sediments and nutrients at the downstream site of Waiakea Stream during 2004 than at the upstream site. During 2005, however, the suspended sediment loads were higher at the downstream site than the upstream site. Construction of a flood control channel between the two sites in 2005 may have contributed to the change in relative suspended-sediment loads.

Nutrient intakes, major food sources and dietary inadequacies of Inuit adults living in three remote communities in Nunavut, Canada.

PubMed

Sharma, S; Hopping, B N; Roache, C; Sheehy, T

2013-12-01

Inuit in Nunavut, Canada, are currently undergoing a nutritional transition that may contribute to an increased prevalence of chronic disease. Information is lacking about the extent to which contemporary Inuit diets are meeting current dietary recommendations. A culturally appropriate quantitative food frequency questionnaire (QFFQ) developed and validated for Inuit in Nunavut, Canada, was used to assess food and nutrient intake in a cross-sectional sample of adults. Participants included 175 women and 36 men with mean (SD) ages of 42.4 (13.2) and 42.1 (15.0) years, respectively. The response rate for those who completed the study was 79% with 208 QFFQs included for analysis. Reported mean daily energy intakes were: men 15,171 kJ (3626 kcal); women 11,593 kJ (2771 kcal). Dietary inadequacy was expressed as the percentage of participants reporting intakes below the sex- and age-specific estimated average requirements (EARs). For nutrients without EARs, adequate intakes were used. Energy and sodium intakes exceeded the recommendations. Less than 10% of participants met recommendations for dietary fibre intake. Vitamin E intakes were below EARs for ≥97% of participants, whereas >20% reported inadequate vitamin A, folate and magnesium intakes. Among women, >50% reported inadequate calcium and vitamin D intakes. Non-nutrient-dense foods contributed 30% of energy, 73% of sugars and 22% of fat. Traditional foods contributed 56% of protein and 49% of iron. The present study demonstrates a relatively high prevalence of inadequate nutrient intakes among Inuit. The results may be used to monitor the nutrition transition among Inuit, evaluate nutritional interventions, and inform public health policy decision-making. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

The contribution of school meals and packed lunch to food consumption and nutrient intakes in UK primary school children from a low income population.

PubMed

Stevens, L; Nelson, M

2011-06-01

The Low Income Diet and Nutrition Survey described the food consumption and nutrient intake of UK children in low income households in 2003-2005. To describe food consumption and nutrient intake associated with school meals and packed lunches, based on a cross-sectional analysis of 680, 24-h dietary recalls from 311 school children aged 4-11 years. In children from low income households, pupils who took a packed lunch consumed more white bread, fats and oils, crisps and confectionery and fewer potatoes (cooked with or without fat) at lunchtime compared to other pupils. Many of these differences persisted when diet was assessed over the day. For younger pupils (4-7 years), packed lunches provided the least amount of folate, the highest amount of sodium, and the highest average percentage of food energy from fat and saturated fatty acids (SFA) compared to free school meals (FSMs). Over the whole day, in both younger (4-7 years) and older (8-11 years) children, there were no notable differences in energy or nutrient intake between those eating a packed lunch or a school meal. Older children's packed lunches contributed a significantly higher proportion of fat, SFA, calcium and sodium to the day's nutrient intake compared to a FSM. In children from low income households, packed lunches are less likely to contribute towards a 'healthier' diet compared to a school meal. The difference was more apparent in younger children. Key differences were the high consumption of sodium, SFA and non-milk extrinsic sugars by pupils who had packed lunches. © 2011 The Authors. Journal compilation © 2011 The British Dietetic Association Ltd.

Mineral constituents profile of biochar derived from diversified waste biomasses: implications for agricultural applications.

PubMed

Zhao, Ling; Cao, Xinde; Wang, Qun; Yang, Fan; Xu, Shi

2013-01-01

The wide distribution and high heterogeneity of different elements in biochars derived from diverse feedstocks make it difficult to regulate their application in soil and to evaluate the maximum potential contribution of the nutrients and trace metals as well as the potential risk of toxic metals. This study classified 20 biochars, covering six typical categories, into three clusters according to their similarity and distance on nutrients and minerals using cluster analysis. Four principle components (PC) were extracted using factor analysis to reduce dimension and clearly characterize the mineral profile of these biochars. The contribution of each group of elements in the PCs to every cluster was clarified. PC1 had a high loading for Mg, Cu, Zn, Al, and Fe; PC2 was related to N, K, and Mn; and PC3 and PC4 mainly represented P and Ca. Cluster 1 included bone dregs and eggshell biochars with PC3 and PC4 as the main contributors. Cluster 2 included waterweeds and waste paper biochars, which were close to shrimp hull and chlorella biochars, with the main contributions being from PC2 and PC4. Cluster 3 included biochars with PC1 as the main contributor. At a soil biochar amendment rate of 50 t ha, the soil nutrients were significantly elevated, whereas the rise in toxic metals was negligible compared with Class I of the China Environmental Quality Standards for Soil. Biochar can potentially supply soil nutrients and trace metals, and different cluster biochars can be applied appropriately to different soils so that excessive or deficient nutrient and metal applications can be avoided. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Contribution of Wastewater Treatment Plant Effluents to Nutrient Dynamics in Aquatic Systems: A Review

NASA Astrophysics Data System (ADS)

Carey, Richard O.; Migliaccio, Kati W.

2009-08-01

Excessive nutrient loading (considering nitrogen and phosphorus) is a major ongoing threat to water quality and here we review the impact of nutrient discharges from wastewater treatment plants (WWTPs) to United States (U.S.) freshwater systems. While urban and agricultural land uses are significant nonpoint nutrient contributors, effluent from point sources such as WWTPs can overwhelm receiving waters, effectively dominating hydrological characteristics and regulating instream nutrient processes. Population growth, increased wastewater volumes, and sustainability of critical water resources have all been key factors influencing the extent of wastewater treatment. Reducing nutrient concentrations in wastewater is an important aspect of water quality management because excessive nutrient concentrations often prevent water bodies from meeting designated uses. WWTPs employ numerous physical, chemical, and biological methods to improve effluent water quality but nutrient removal requires advanced treatment and infrastructure that may be economically prohibitive. Therefore, effluent nutrient concentrations vary depending on the particular processes used to treat influent wastewater. Increasingly stringent regulations regarding nutrient concentrations in discharged effluent, along with greater freshwater demand in populous areas, have led to the development of extensive water recycling programs within many U.S. regions. Reuse programs provide an opportunity to reduce or eliminate direct nutrient discharges to receiving waters while allowing for the beneficial use of reclaimed water. However, nutrients in reclaimed water can still be a concern for reuse applications, such as agricultural and landscape irrigation.

Wildfire Effects on In-stream Nutrient Processing and Hydrologic Transport

NASA Astrophysics Data System (ADS)

Rhea, A.; Covino, T. P.; Rhoades, C.; Fegel, T.

2017-12-01

In many forests throughout the Western U.S., drought, climate change, and growing fuel loads are contributing to increased fire frequency and severity. Wildfires can influence watershed nutrient retention as they fundamentally alter the biological composition and physical structure in upland landscapes, riparian corridors, and stream channels. While numerous studies have documented substantial short-term increases in stream nutrient concentrations and export (particularly reactive nitrogen, N) following forest fires, the long-term implications for watershed nutrient cycling remain unclear. For example, recent work indicates that nitrate concentrations and export can remain elevated for a decade or more following wildfire, yet the controls on these processes are unknown. In this research, we use empirical observations from nutrient tracer injections, nutrient diffusing substrates, and continuous water quality monitoring to isolate biological and physical controls on nutrient export across a burn-severity gradient. Tracer results demonstrate substantial stream-groundwater exchange, but little biological nutrient uptake in burned streams. This in part explains patterns of elevated nutrient export. Paired nutrient diffusing substrate experiments allow us to further investigate shifts in N, phosphorus, and carbon limitation that may suppress post-fire stream nutrient uptake. By isolating the mechanisms that reduce the capacity of fire-affected streams to retain and transform nutrient inputs, we can better predict dynamics in post-fire water quality and help prioritize upland and riparian restoration.

[Diversity of soil fauna in corn fields in Huang-Huai-Hai Plain of China under effects of conservation tillage].

PubMed

Zhu, Qiang-Gen; Zhu, An-Ning; Zhang, Jia-Bao; Zhang, Huan-Chao; Huang, Ping; Zhang, Cong-Zhi

2009-10-01

An investigation was made on the abundance and diversity of soil fauna in the corn fields under conventional and conservation tillage in Huang-Huai-Hai Plain of China. The abundance and diversity of soil fauna were higher at corn maturing (September) than at its jointing stage (July), and higher at jointing stage under conservation tillage than under conventional tillage. Soil fauna mainly distributed in surface soil layer (0-10 cm), but still had a larger number in 10-20 cm layer under conservation tillage. The individuals of acari, diptera, diplura, and microdrile oligochaetes, especially those of acari, were higher under conservation tillage than under conventional tillage. At maturing stage, an obvious effect of straw-returning under conservation tillage was observed, i. e., the more the straw returned, the higher the abundance of soil fauna, among which, the individuals of collembola, acari, coleopteran, and psocoptera, especially those of collembolan, increased significantly. The abundance of collembola at both jointing and maturing stages was significantly positively correlated with the quantity of straw returned, suggesting that collembola played an important role in straw decomposition and nutrient cycling.

Contribution of Pollinator-Mediated Crops to Nutrients in the Human Food Supply

PubMed Central

Eilers, Elisabeth J.; Kremen, Claire; Smith Greenleaf, Sarah; Garber, Andrea K.; Klein, Alexandra-Maria

2011-01-01

The contribution of nutrients from animal pollinated world crops has not previously been evaluated as a biophysical measure for the value of pollination services. This study evaluates the nutritional composition of animal-pollinated world crops. We calculated pollinator dependent and independent proportions of different nutrients of world crops, employing FAO data for crop production, USDA data for nutritional composition, and pollinator dependency data according to Klein et al. (2007). Crop plants that depend fully or partially on animal pollinators contain more than 90% of vitamin C, the whole quantity of Lycopene and almost the full quantity of the antioxidants β-cryptoxanthin and β-tocopherol, the majority of the lipid, vitamin A and related carotenoids, calcium and fluoride, and a large portion of folic acid. Ongoing pollinator decline may thus exacerbate current difficulties of providing a nutritionally adequate diet for the global human population. PMID:21731717

Environmental Characteristics and Geographic Information System Applications for the Development of Nutrient Thresholds in Oklahoma Streams

USGS Publications Warehouse

Masoner, Jason R.; Haggard, Brian E.; Rea, Alan

2002-01-01

The U.S.Environmental Protection Agency has developed nutrient criteria using ecoregions to manage and protect rivers and streams in the United States. Individual states and tribes are encouraged by the U.S. Environmental Protection Agency to modify or improve upon the ecoregion approach. The Oklahoma Water Resources Board uses a dichotomous process that stratifies streams using environmental characteristics such as stream order and stream slope. This process is called the Use Support Assessment Protocols, subchapter15. The Use Support Assessment Protocols can be used to identify streams threatened by excessive amounts of nutrients, dependant upon a beneficial use designation for each stream. The Use Support Assessment Protocols, subchapter 15 uses nutrient and environmental characteristic thresholds developed from a study conducted in the Netherlands, but the Oklahoma Water Resources Board wants to modify the thresholds to reflect hydrologic and ecological conditions relevant to Oklahoma streams and rivers. Environmental characteristics thought to affect impairment from nutrient concentrations in Oklahoma streams and rivers were determined for 798 water-quality sites in Oklahoma. Nutrient, chlorophyll, water-properties, and location data were retrieved from the U.S. Environmental Protection Agency STORET database including data from the U.S. Geological Survey, Oklahoma Conservation Commission, and Oklahoma Water Resources Board. Drainage-basin area, stream order, stream slope, and land-use proportions were determined for each site using a Geographic Information System. The methods, procedures, and data sets used to determine the environmental characteristics are described.

Conventional foods, followed by dietary supplements and fortified foods, are the key sources of vitamin D, vitamin B6, and selenium intake in Dutch participants of the NU-AGE study.

PubMed

Berendsen, Agnes A M; van Lieshout, Lilou E L M; van den Heuvel, Ellen G H M; Matthys, Christophe; Péter, Szabolcs; de Groot, Lisette C P G M

2016-10-01

With aging, energy needs decrease, necessitating a more nutrient-dense diet to meet nutritional needs. To bridge this gap, the use of nutrient-dense foods, fortified foods, and dietary supplements can be important. This observational study aims to describe current micronutrient intakes of Dutch elderly and to identify the contribution of nutrient-dense foods, fortified foods, and dietary supplements to the intake of micronutrients that are often inadequately consumed in Dutch elderly. Data of 245 Dutch volunteers from the NU-AGE study aged 65 to 80 years were used. Dietary intake was assessed by means of 7-day food records, and dietary supplement use was recorded with an additional questionnaire. Information on fortified foods was obtained from the Dutch Food Composition Table 2011. Nutrient density of foods was evaluated using the Nutrient Rich Food 9.3 score. The percentages of participants not meeting their average requirement were high for vitamin D (99%), selenium (41%), and vitamin B6 (54%) based on conventional foods and also when taking into account fortified foods (98%, 41%, and 27%, respectively) and vitamin and mineral supplements (87%, 36%, and 20%, respectively). Conventional foods were the main source of vitamin D, vitamin B6, and selenium intake (42%, 45%, and 82%, respectively), followed by vitamin and mineral supplements (41%, 44%, and 18%) and fortified foods (17%, 11%, and 1%). Foods with the highest nutrient density contributed most to total vitamin B6 intake only. To optimize nutrient intakes of elderly, combinations of natural food sources, fortified foods, and dietary supplements should be considered. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Electric-field-enhanced nutrient consumption in dielectric biomaterials that contain anchorage-dependent cells.

PubMed

Belfiore, Laurence A; Floren, Michael L; Belfiore, Carol J

2012-02-01

This research contribution addresses electric-field stimulation of intra-tissue mass transfer and cell proliferation in viscoelastic biomaterials. The unsteady state reaction-diffusion equation is solved according to the von Kármán-Pohlhausen integral method of boundary layer analysis when nutrient consumption and tissue regeneration occur in response to harmonic electric potential differences across a parallel-plate capacitor in a dielectric-sandwich configuration. The partial differential mass balance with diffusion and electro-kinetic consumption contains the Damköhler (Λ(2)) and Deborah (De) numbers. Zero-field and electric-field-sensitive Damköhler numbers affect nutrient boundary layer growth. Diagonal elements of the 2nd-rank diffusion tensor are enhanced in the presence of weak electric fields, in agreement with the formalism of equilibrium and nonequilibrium thermodynamics. Induced dipole polarization density within viscoelastic biomaterials is calculated via the real and imaginary components of the complex dielectric constant, according to the Debye equation, to quantify electro-kinetic stimulation. Rates of nutrient consumption under zero-field conditions are described by third-order kinetics that include local mass densities of nutrients, oxygen, and attached cells. Thinner nutrient boundary layers are stabilized at shorter dimensionless diffusion times when the zero-field intra-tissue Damköhler number increases above its initial-condition-sensitive critical value [i.e., {Λ(2)(zero-field)}(critical)≥53, see Eq. (23)], such that the biomaterial core is starved of essential ingredients required for successful proliferation. When tissue regeneration occurs above the critical electric-field-sensitive intra-tissue Damköhler number, the electro-kinetic contribution to nutrient consumption cannot be neglected. The critical electric-field-sensitive intra-tissue Damköhler number is proportional to the Deborah number. Copyright © 2011 Elsevier B.V. All rights reserved.

Nutrient Dynamics in Riparian Ecosystems. Chapter 6 in Riparian Ecosystems, Volume 1: Science Synthesis and Management Implications

EPA Science Inventory

This report will be a chapter in an updated Riparian BMP manual developed by the State of WA Fish and Wildlife Dept. Jana Compton and I were asked to contribute the chapter on nutrients in riparian ecosystems based on experience and research in riparian systems. The document is...

Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, nutrient concentrations, and plant nutrition and growth

USDA-ARS?s Scientific Manuscript database

Liming agents in irrigation water, typically associated with carbonates and bicarbonates of calcium and magnesium, contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient availability imbalan...

Fine-root growth in a forested bog is seasonally dynamic, but shallowly distributed in nutrient-poor peat

Treesearch

Colleen M. Iversen; Joanne Childs; Richard J. Norby; Todd A. Ontl; Randall K. Kolka; Deanne J. Brice; Karis J. McFarlane; Paul J. Hanson

2017-01-01

Background and aims. Fine roots contribute to ecosystem carbon, water, and nutrient fluxes through resource acquisition, respiration, exudation, and turnover, but are understudied in peatlands. We aimed to determine how the amount and timing of fine-root growth in a forested, ombrotrophic bog varied across gradients of vegetation density, peat...

Regional assessments of the Nation's water quality—Improved understanding of stream nutrient sources through enhanced modeling capabilities

USGS Publications Warehouse

Preston, Stephen D.; Alexander, Richard B.; Woodside, Michael D.

2011-01-01

The U.S. Geological Survey (USGS) recently completed assessments of stream nutrients in six major regions extending over much of the conterminous United States. SPARROW (SPAtially Referenced Regressions On Watershed attributes) models were developed for each region to explain spatial patterns in monitored stream nutrient loads in relation to human activities and natural resources and processes. The model information, reported by stream reach and catchment, provides contrasting views of the spatial patterns of nutrient source contributions, including those from urban (wastewater effluent and diffuse runoff from developed land), agricultural (farm fertilizers and animal manure), and specific background sources (atmospheric nitrogen deposition, soil phosphorus, forest nitrogen fixation, and channel erosion).

On the relationship between residue structural environment and sequence conservation in proteins.

PubMed

Liu, Jen-Wei; Lin, Jau-Ji; Cheng, Chih-Wen; Lin, Yu-Feng; Hwang, Jenn-Kang; Huang, Tsun-Tsao

2017-09-01

Residues that are crucial to protein function or structure are usually evolutionarily conserved. To identify the important residues in protein, sequence conservation is estimated, and current methods rely upon the unbiased collection of homologous sequences. Surprisingly, our previous studies have shown that the sequence conservation is closely correlated with the weighted contact number (WCN), a measure of packing density for residue's structural environment, calculated only based on the C α positions of a protein structure. Moreover, studies have shown that sequence conservation is correlated with environment-related structural properties calculated based on different protein substructures, such as a protein's all atoms, backbone atoms, side-chain atoms, or side-chain centroid. To know whether the C α atomic positions are adequate to show the relationship between residue environment and sequence conservation or not, here we compared C α atoms with other substructures in their contributions to the sequence conservation. Our results show that C α positions are substantially equivalent to the other substructures in calculations of various measures of residue environment. As a result, the overlapping contributions between C α atoms and the other substructures are high, yielding similar structure-conservation relationship. Take the WCN as an example, the average overlapping contribution to sequence conservation is 87% between C α and all-atom substructures. These results indicate that only C α atoms of a protein structure could reflect sequence conservation at the residue level. © 2017 Wiley Periodicals, Inc.

Effect of plants in constructed wetlands for organic carbon and nutrient removal: a review of experimental factors contributing to higher impact and suggestions for future guidelines.

PubMed

Jesus, João M; Danko, Anthony S; Fiúza, António; Borges, Maria-Teresa

2018-02-01

Constructed wetland is a proven technology for water pollution removal, but process mechanisms and their respective contribution are not fully understood. The present review details the effect of plants on removal efficiency of constructed wetlands by focusing on literature that includes experiments with unplanted controls for organic carbon and nutrient (N and P) removal. The contribution of plant direct uptake is also assessed. Although it was found that several studies, mostly at laboratory or pilot scales, showed no statistical differences between planted and unplanted controls, some factors were found that help maximize the effect of plants. This study intends to contribute to a better understanding of the significance of the effect of plants in a constructed wetland, as well as to suggest a set of experimental guidelines in this field.

Integrating abundance and functional traits reveals new global hotspots of fish diversity.

PubMed

Stuart-Smith, Rick D; Bates, Amanda E; Lefcheck, Jonathan S; Duffy, J Emmett; Baker, Susan C; Thomson, Russell J; Stuart-Smith, Jemina F; Hill, Nicole A; Kininmonth, Stuart J; Airoldi, Laura; Becerro, Mikel A; Campbell, Stuart J; Dawson, Terence P; Navarrete, Sergio A; Soler, German A; Strain, Elisabeth M A; Willis, Trevor J; Edgar, Graham J

2013-09-26

Species richness has dominated our view of global biodiversity patterns for centuries. The dominance of this paradigm is reflected in the focus by ecologists and conservation managers on richness and associated occurrence-based measures for understanding drivers of broad-scale diversity patterns and as a biological basis for management. However, this is changing rapidly, as it is now recognized that not only the number of species but the species present, their phenotypes and the number of individuals of each species are critical in determining the nature and strength of the relationships between species diversity and a range of ecological functions (such as biomass production and nutrient cycling). Integrating these measures should provide a more relevant representation of global biodiversity patterns in terms of ecological functions than that provided by simple species counts. Here we provide comparisons of a traditional global biodiversity distribution measure based on richness with metrics that incorporate species abundances and functional traits. We use data from standardized quantitative surveys of 2,473 marine reef fish species at 1,844 sites, spanning 133 degrees of latitude from all ocean basins, to identify new diversity hotspots in some temperate regions and the tropical eastern Pacific Ocean. These relate to high diversity of functional traits amongst individuals in the community (calculated using Rao's Q), and differ from previously reported patterns in functional diversity and richness for terrestrial animals, which emphasize species-rich tropical regions only. There is a global trend for greater evenness in the number of individuals of each species, across the reef fish species observed at sites ('community evenness'), at higher latitudes. This contributes to the distribution of functional diversity hotspots and contrasts with well-known latitudinal gradients in richness. Our findings suggest that the contribution of species diversity to a range of ecosystem functions varies over large scales, and imply that in tropical regions, which have higher numbers of species, each species contributes proportionally less to community-level ecological processes on average than species in temperate regions. Metrics of ecological function usefully complement metrics of species diversity in conservation management, including when identifying planning priorities and when tracking changes to biodiversity values.

Ecology of bison, elk, and vegetation in an arid ecosystem

USGS Publications Warehouse

Schoenecker, Kathryn A.

2012-01-01

Herbivory has profound effects on vegetation production and structure in many different plant communities. The influence of herbivory on plants and ultimately ecosystem processes is shaped by the types of plants consumed, the intensity of herbivory, the evolutionary history of grazing, and the availability of water and nutrients to plants. The effect of ungulate herbivores on vegetation is of great interest to ecologists, land managers and agriculturalists. In addition, the Department of Interior recently established a Bison Conservation Initiative to provide for the conservation and restoration of North American plains- and wood bison, which includes establishing new populations and expanding existing populations. The San Luis Valley, Colorado, is being considered as a potential location for a bison conservation herd. Resource managers need to know the vegetation impacts of adding a second large ungulate to a system that already has elk.

Diversity and composition of sediment bacteria in subtropical coastal wetlands of North Stradbroke Island, Queensland, Australia

NASA Astrophysics Data System (ADS)

Chuvochina, Maria; Sampayo, Eugenia; Welti, Nina; Hayes, Matthew; Lu, Yang; Lovelock, Catherine; Lockington, David

2013-04-01

Coastal wetlands provide a wide variety of important ecosystem services but continue to suffer disturbance, degradation and deforestation. Sediment bacteria are responsible for major nutrient transformation and recycling in these ecosystems. Insight into microbial community composition and the factors that determine them may improve our understanding of biogeochemical processes, food web dynamics, biodegradation processes and, thus, help to develop the management strategies for preserving the ecosystem health and services. Characterizing shifts in community taxa along environmental gradients has been shown to provide a useful tool for determining the major drivers affecting community structure and function. North Stradbroke Island (NSI) in Southern Queensland presents considerable habitat diversity including variety of groundwater dependent ecosystems such as lakes, swamps, sedge-like salt marshes and mangroves. Ecological responses of continuous groundwater extraction for municipal purposes and sand mining operations on NSI are still need to be assessed in order to protect its unique environment. Changes in coastal hydrology due to either climate change or human activity may directly affect microbial populations and, thus, biogeochemical cycles of nutrients. These may result in altering/losing some ecosystem services provided by coastal wetlands. In this study we examine microbial diversity and determine environmental controls on bacterial community structure along a natural transition from freshwater forested wetland (melaleuca woodland), sedge-like salt marsh and into mangroves located at NSI. The study area is characterized by significant groundwater flow, nutrient limitation and sharp transition from one ecosystem type to another. Sediment cores (0-5 cm and 20-25 cm depth) were collected from three representative sites of each zone (mangroves - salt marsh - freshwater wetland) along the salinity gradient in August 2012. Subsamples were set aside for use in chemical analyses, microbiological analysis and for porewater extraction. Microbial community structure and diversity are assessed using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments and barcoded pyrosequencing. To evaluate the relationships between microbial communities and environmental variables we use bioinformatical and statistical tools. Physico-chemical parameters included measurements of sediment pH, temperature, salinity and nutrients composition. Background information regarding hydrology and vegetation is incorporated in the study. Sediment bacteria play a vital role in wetland ecological function, and they are very sensitive to environmental changes. Considering coastal wetlands of NSI as a model area, our study may contribute to the knowledge of factors shaping microbial diversity in tropical wetlands, help to gain insight into the microbe-nutrient-plant relationships, and also serve as background for conservation plans to safeguard these ecosystems.

Ecosystem Services Derived from Wetland Conservation Practices in the United States Prairie Pothole Region with an Emphasis on the U.S. Department of Agriculture Conservation Reserve and Wetlands Reserve Programs

USGS Publications Warehouse

Gleason, Robert A.; Laubhan, Murray K.; Euliss, Ned H.

2008-01-01

Implementation of the U.S. Department of Agriculture (USDA) Conservation Reserve Program (CRP) and Wetlands Reserve Program (WRP) has resulted in the restoration of approximately 2,200,000 ha (5,436,200 acres) of wetland and grassland habitats in the Prairie Pothole Region. These restored habitats are known to provide various ecosystem services; however, little work has been conducted to quantify and verify benefits on program lands (lands enrolled in the CRP and WRP) in agriculturally dominated landscapes of the Prairie Pothole Region. To address this need, the U.S. Geological Survey (USGS), in collaboration with the USDA Farm Service Agency and Natural Resources Conservation Service, initiated a study to develop and apply approaches to quantify changes in ecosystem services resulting from wetland restoration activities funded by the USDA. To accomplish this goal, the USGS conducted a comprehensive, stratified survey of 204 catchments (wetland and surrounding uplands contributing runoff to the wetland) in 1997 and 270 catchments in 2004 to gather data necessary for estimating various ecosystem services. In 1997 and 2004, the surveys included catchments with seasonal and semipermanent wetlands that were restored as part of USDA conservation programs, as well as nonprogram catchments in native prairie. Additionally, in 2004 data collection was expanded to include temporary wetlands for all treatments and nonprogram cropped catchments for all wetland classes: temporary, seasonal, and semipermanent. A key element in the sample design is that catchments span an alteration gradient ranging from highly altered, such as cropland, to minimally altered, such as native prairie. Therefore, we evaluated restoration programs by comparing changes in program (restored) catchments to nonprogram (cropland and native prairie) catchments. Information collected during both surveys included easily measured soil, vegetation, and morphological variables that were used to estimate the following ecosystem services: plant community quality and richness, carbon sequestration, floodwater storage, sediment and nutrient reduction, and potential wildlife habitat suitability. In this report, we evaluate the extent that these ecosystem services changed in restored wetlands relative to cropland and native prairie baselines. In most cases, our results indicate restoration activities funded by the USDA have positively influenced ecosystem services in comparison to a cropped wetland baseline; however, most benefits were only considered at a site-specific scale, and better quantification of off-site benefits associated with conservation programs will require detailed spatial data on all land areas enrolled in conservation programs.

Long-Term Changes in Nitrogen Budgets and Retention in the Elbe Estuary

NASA Astrophysics Data System (ADS)

Eisele, Annika; van Beusekom, Justus E. E.; Wirtz, Kai

2016-04-01

Eutrophication remains one of the major factors influencing the ecological state of coastal ecosystems. Coastal eutrophication is in turn intimately linked to riverine nutrient loads. At the freshwater side of the estuary, nutrient loads can easily be quantified but estuarine processes including organic matter import from the sea and loss factors like denitrification can modify the actual nutrient loads reaching the coastal seas. We quantified and localized nutrient retention processes by analyzing changes of nutrient concentrations along the estuary and constructing nutrient budgets. Two methods -the Officer method based on conservative mixing and a new method based on changes in nitrogen concentrations along the freshwater part of the estuary- were compared using long term records for the Elbe River, a major European waterway. Nutrient budgets and dynamics reveal that nutrient retention processes in the water column play a substantial role in the Elbe River. Overall, ~25 mio mol/day N are imported into the Elbe estuary and ~20 mio mol/day DIN is exported, with obvious variations depending on river discharge and season. A nitrogen loss of about 20% falls within the range found in other studies. Whereas in the 1980s a significant part of the nitrogen input was retained by the estuary, in the 1990s and 2000s most of the imported total nitrogen was exported as DIN. At present, the retention of nitrogen -presumably due to increased denitrification- increases again. As these long-term changes in the retention capacity of the Elbe were supported by both methods, the calibrated station-based approach can now be used to calculate nutrient budgets in estuaries where no or only few transect data are available, such as the Weser and Ems estuary. Our presentation will finally discuss the possible impact of increased phytoplankton import from the Elbe River and increased import of suspended matter from the North Sea ecosystem on estuarine nitrogen dynamics.

Connectedness of land use, nutrients, primary production, and fish assemblages in oxbow lakes

USGS Publications Warehouse

Miranda, Leandro E.; Andrews, Caroline S.; Kroger, Robert

2013-01-01

We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture.

Conservative nutrient use by big-leaf mahogany (Swietenia macrophylla King) planted under contrasting environmental conditions

Treesearch

E. Medina; E. Cuevas; A.E. Lugo; E. Terezo; J. Jimenez-Osornio; P.A. Macario-Mendoza; P. Montanez

2014-01-01

We analyzed the nutritional composition and isotope ratios (C and N) of big-leaf mahogany (Swietenia macrophylla King) leaves in plantations established on contrasting soils and climates in Central America (State of Quintana Roo, Yucatan, Mexico) and South America (State of Para, Brazil). The objective was to determine the adaptability of this species to large...

Inoculating Acacia koa with Bradyrhizobium and applying fertilizer in the nursery: effects on nodule formation and seedling growth

Treesearch

R. Kasten Dumroese; Douglass F. Jacobs; Anthony S. Davis

2009-01-01

Restoration of Acacia koa A. Gray (koa) forests on degraded sites in Hawaii is important for conservation of rare, endemic plants and animals and is often accomplished by planting nursery-grown seedlings. To be successful after outplanting, koa seedlings must access sufficient nutrients from the soil and outcompete other vegetation. Forming symbiotic...

The importance and conservation of ectomycorrizal fungal diversity in forest ecosystems: lessons from Europe and the Pacific Northwest.

Treesearch

Michael P. Amaranthus

1998-01-01

Ectomycorrhizal fungi (EMF) consist of about 5,000 species and profoundly affect forest ecosystems by mediating nutrient and water uptake, protecting roots from pathogens and environmental extremes, and maintaining soil structure and forest food webs. Diversity of EMF likely aids forest ecosystem resilience in the face of changing environmental factors such as...

Subirrigation for production of native plants in nurseries - concepts, current knowledge, and implementation

Treesearch

Justin L. Schmal; Kas Dumroese; Anthony S. Davis; Jeremy Pinto; Douglass F. Jacobs

2011-01-01

Subirrigation, a method whereby water is allowed to move upward into the growing medium by capillary action, has been the focus of recent research in forest and conservation nurseries growing a wide variety of native plants. Subirrigation reduces the amount of water needed for producing high-quality plants, discharged wastewater, and leaching of nutrients compared with...

Abiotic Stresses Shift Belowground Populus-Associated Bacteria Toward a Core Stress Microbiome

PubMed Central

Carter, Kelsey R.; Carrell, Alyssa A.; Jun, Se-Ran; Jawdy, Sara S.; Vélez, Jessica M.; Gunter, Lee E.; Yang, Zamin; Nookaew, Intawat; Engle, Nancy L.; Lu, Tse-Yuan S.; Schadt, Christopher W.; Tschaplinski, Timothy J.; Tuskan, Gerald A.; Pelletier, Dale A.; Weston, David J.

2018-01-01

ABSTRACT Adverse growth conditions can lead to decreased plant growth, productivity, and survival, resulting in poor yields or failure of crops and biofeedstocks. In some cases, the microbial community associated with plants has been shown to alleviate plant stress and increase plant growth under suboptimal growing conditions. A systematic understanding of how the microbial community changes under these conditions is required to understand the contribution of the microbiome to water utilization, nutrient uptake, and ultimately yield. Using a microbiome inoculation strategy, we studied how the belowground microbiome of Populus deltoides changes in response to diverse environmental conditions, including water limitation, light limitation (shading), and metal toxicity. While plant responses to treatments in terms of growth, photosynthesis, gene expression and metabolite profiles were varied, we identified a core set of bacterial genera that change in abundance in response to host stress. The results of this study indicate substantial structure in the plant microbiome community and identify potential drivers of the phytobiome response to stress. IMPORTANCE The identification of a common “stress microbiome” indicates tightly controlled relationships between the plant host and bacterial associates and a conserved structure in bacterial communities associated with poplar trees under different growth conditions. The ability of the microbiome to buffer the plant from extreme environmental conditions coupled with the conserved stress microbiome observed in this study suggests an opportunity for future efforts aimed at predictably modulating the microbiome to optimize plant growth. PMID:29404422

Abiotic Stresses Shift Belowground Populus -Associated Bacteria Toward a Core Stress Microbiome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Timm, Collin M.; Carter, Kelsey R.; Carrell, Alyssa A.

Adverse growth conditions can lead to decreased plant growth, productivity, and survival, resulting in poor yields or failure of crops and biofeedstocks. In some cases, the microbial community associated with plants has been shown to alleviate plant stress and increase plant growth under suboptimal growing conditions. A systematic understanding of how the microbial community changes under these conditions is required to understand the contribution of the microbiome to water utilization, nutrient uptake, and ultimately yield. Using a microbiome inoculation strategy, we studied how the belowground microbiome ofPopulus deltoideschanges in response to diverse environmental conditions, including water limitation, light limitation (shading),more » and metal toxicity. While plant responses to treatments in terms of growth, photosynthesis, gene expression and metabolite profiles were varied, we identified a core set of bacterial genera that change in abundance in response to host stress. The results of this study indicate substantial structure in the plant microbiome community and identify potential drivers of the phytobiome response to stress.The identification of a common “stress microbiome” indicates tightly controlled relationships between the plant host and bacterial associates and a conserved structure in bacterial communities associated with poplar trees under different growth conditions. The ability of the microbiome to buffer the plant from extreme environmental conditions coupled with the conserved stress microbiome observed in this study suggests an opportunity for future efforts aimed at predictably modulating the microbiome to optimize plant growth.« less

Abiotic Stresses Shift Belowground Populus -Associated Bacteria Toward a Core Stress Microbiome

DOE PAGES

Timm, Collin M.; Carter, Kelsey R.; Carrell, Alyssa A.; ...

2018-01-23

Adverse growth conditions can lead to decreased plant growth, productivity, and survival, resulting in poor yields or failure of crops and biofeedstocks. In some cases, the microbial community associated with plants has been shown to alleviate plant stress and increase plant growth under suboptimal growing conditions. A systematic understanding of how the microbial community changes under these conditions is required to understand the contribution of the microbiome to water utilization, nutrient uptake, and ultimately yield. Using a microbiome inoculation strategy, we studied how the belowground microbiome ofPopulus deltoideschanges in response to diverse environmental conditions, including water limitation, light limitation (shading),more » and metal toxicity. While plant responses to treatments in terms of growth, photosynthesis, gene expression and metabolite profiles were varied, we identified a core set of bacterial genera that change in abundance in response to host stress. The results of this study indicate substantial structure in the plant microbiome community and identify potential drivers of the phytobiome response to stress.The identification of a common “stress microbiome” indicates tightly controlled relationships between the plant host and bacterial associates and a conserved structure in bacterial communities associated with poplar trees under different growth conditions. The ability of the microbiome to buffer the plant from extreme environmental conditions coupled with the conserved stress microbiome observed in this study suggests an opportunity for future efforts aimed at predictably modulating the microbiome to optimize plant growth.« less

Bacteria Contribute to Sediment Nutrient Release and Reflect Progressed Eutrophication-Driven Hypoxia in an Organic-Rich Continental Sea

PubMed Central

Sinkko, Hanna; Lukkari, Kaarina; Sihvonen, Leila M.; Sivonen, Kaarina; Leivuori, Mirja; Rantanen, Matias; Paulin, Lars; Lyra, Christina

2013-01-01

In the sedimental organic matter of eutrophic continental seas, such as the largest dead zone in the world, the Baltic Sea, bacteria may directly participate in nutrient release by mineralizing organic matter or indirectly by altering the sediment’s ability to retain nutrients. Here, we present a case study of a hypoxic sea, which receives riverine nutrient loading and in which microbe-mediated vicious cycles of nutrients prevail. We showed that bacterial communities changed along the horizontal loading and vertical mineralization gradients in the Gulf of Finland of the Baltic Sea, using multivariate statistics of terminal restriction fragments and sediment chemical, spatial and other properties of the sampling sites. The change was mainly explained by concentrations of organic carbon, nitrogen and phosphorus, which showed strong positive correlation with Flavobacteria, Sphingobacteria, Alphaproteobacteria and Gammaproteobacteria. These bacteria predominated in the most organic-rich coastal surface sediments overlain by oxic bottom water, whereas sulphate-reducing bacteria, particularly the genus Desulfobacula, prevailed in the reduced organic-rich surface sediments in the open sea. They correlated positively with organic nitrogen and phosphorus, as well as manganese oxides. These relationships suggest that the bacterial groups participated in the aerobic and anaerobic degradation of organic matter and contributed to nutrient cycling. The high abundance of sulphate reducers in the surficial sediment layers reflects the persistence of eutrophication-induced hypoxia causing ecosystem-level changes in the Baltic Sea. The sulphate reducers began to decrease below depths of 20 cm, where members of the family Anaerolineaceae (phylum Chloroflexi) increased, possibly taking part in terminal mineralization processes. Our study provides valuable information on how organic loading affects sediment bacterial community compositions, which consequently may maintain active nutrient recycling. This information is needed to improve our understanding on nutrient cycling in shallow seas where the dead zones are continuously spreading worldwide. PMID:23825619

Wind-induced flow velocity effects on nutrient concentrations at Eastern Bay of Lake Taihu, China.

PubMed

Jalil, Abdul; Li, Yiping; Du, Wei; Wang, Jianwei; Gao, Xiaomeng; Wang, Wencai; Acharya, Kumud

2017-07-01

Shallow lakes are highly sensitive to respond internal nutrient loading due to wind-induced flow velocity effects. Wind-induced flow velocity effects on nutrient suspension were investigated at a long narrow bay of large shallow Lake Taihu, the third largest freshwater lake in China. Wind-induced reverse/compensation flow and consistent flow field probabilities at vertical column of the water were measured. The probabilities between the wind field and the flow velocities provided a strong correlation at the surface (80.6%) and the bottom (65.1%) layers of water profile. Vertical flow velocity profile analysis provided the evidence of delay response time to wind field at the bottom layer of lake water. Strong wind field generated by the west (W) and west-north-west (WNW) winds produced displaced water movements in opposite directions to the prevailing flow field. An exponential correlation was observed between the current velocities of the surface and the bottom layers while considering wind speed as a control factor. A linear model was developed to correlate the wind field-induced flow velocity impacts on nutrient concentration at the surface and bottom layers. Results showed that dominant wind directions (ENE, E, and ESE) had a maximum nutrient resuspension contribution (nutrient resuspension potential) of 34.7 and 43.6% at the surface and the bottom profile layers, respectively. Total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) average concentrations were 6.38, 1.5, and 0.03 mg/L during our field experiment at Eastern Bay of Lake Taihu. Overall, wind-induced low-to-moderate hydrodynamic disturbances contributed more in nutrient resuspension at Eastern Bay of Lake Taihu. The present study can be used to understand the linkage between wind-induced flow velocities and nutrient concentrations for shallow lakes (with uniform morphology and deep margins) water quality management and to develop further models.

Nutrient trends through time in Sweden's Baltic Drainage Area

NASA Astrophysics Data System (ADS)

Fischer, I.; Destouni, G.; Prieto, C.

2015-12-01

Changes in climate and land-use have and will continue to modify regional hydrology, in turn impacting environmental health, agricultural productivity and water resource quality and availability. The Baltic region is an area of interest as the coast spans nine countries- serving over 100 million people. The Baltic Sea contains one of the largest human caused hypoxic dead zones due to eutrophication driven by anthropogenic excess loading of nutrients. Policies to reduce these loads include also international directives and agreements, such as the EU Water Framework Directive, adopted in 2000 to protect and improve water quality throughout the European Union, and the Baltic Sea Action Plan under the Helsinki Commission aimed specifically at reducing the nutrient loading to and mitigating the eutrophication of the Baltic Sea. In light of these policies and amidst the number of studies on the Baltic Sea we ask, using the accessible nutrient and discharge data what does nutrient loading look like today? Are the most excessive loads going down? Observed nutrient and flow time series across Sweden allow for answering these questions, by spatial and temporal trend analysis of loads from various parts of Sweden to the Baltic Sea. Analyzing these observed time series in conjunction with the ecological health status classifications of the EU Water Framework Directive, allows in particular for answering the question if the loads into the water bodies with the poorest water quality, and from those to the Baltic Sea, are improving, being maintained or deteriorating. Such insight is required to contribute to relevant and efficient water and nutrient load management. Furthermore, empirically calculating nutrient loads, rather than only modeling, reveals that the water body health classification may not reflect what water bodies actually contribute the heaviest loads to the Baltic Sea. This work also underscores the importance of comprehensive analysis of all available data from long term monitoring programs over large spatial scales, including large water quality gradients, in order to assess and address water management problems of today and the future.

Processed Food Contributions to Energy and Nutrient Intake Differ among US Children by Race/Ethnicity.

PubMed

Eicher-Miller, Heather A; Fulgoni, Victor L; Keast, Debra R

2015-12-02

This study determined and compared the mean daily intake of energy and nutrients from processed foods by level of processing (minimally processed; processed for preservation, nutrient enhancement, and freshness; mixtures of combined ingredients; ready-to-eat processed foods; and prepared foods/meals) among non-Hispanic white, non-Hispanic black, and Mexican American US children. Data from participants 2-18 years old (n = 10,298) of the nationally representative cross-sectional National Health and Nutrition Examination Survey 2003-2008 with a complete one day, 24-h dietary recall were used to determine mean intake of energy and nutrients recommended for increase and decrease, as per the 2010 Dietary Guidelines for Americans, among child race/ethnic groups by category of food processing. Regression analysis was used to estimate and compare covariate-adjusted (gender, age, and poverty-income-level) least square means (p < 0.05/3 race/ethnic groups). All children, regardless of race or ethnicity consumed processed foods. Approximately 66% to 84% of total daily energy, saturated fat, cholesterol, fiber, total sugar, added sugars, calcium, vitamin D, potassium, and sodium intake are contributed by one of the five categories of processed foods. Clinicians and policy should primarily advise consideration of the energy and nutrient composition of foods, rather than the processing level, when selecting a healthy diet for children.

Processed Food Contributions to Energy and Nutrient Intake Differ among US Children by Race/Ethnicity

PubMed Central

Eicher-Miller, Heather A.; Fulgoni, Victor L.; Keast, Debra R.

2015-01-01

This study determined and compared the mean daily intake of energy and nutrients from processed foods by level of processing (minimally processed; processed for preservation, nutrient enhancement, and freshness; mixtures of combined ingredients; ready-to-eat processed foods; and prepared foods/meals) among non-Hispanic white, non-Hispanic black, and Mexican American US children. Data from participants 2–18 years old (n = 10,298) of the nationally representative cross-sectional National Health and Nutrition Examination Survey 2003–2008 with a complete one day, 24-h dietary recall were used to determine mean intake of energy and nutrients recommended for increase and decrease, as per the 2010 Dietary Guidelines for Americans, among child race/ethnic groups by category of food processing. Regression analysis was used to estimate and compare covariate-adjusted (gender, age, and poverty-income-level) least square means (p < 0.05/3 race/ethnic groups). All children, regardless of race or ethnicity consumed processed foods. Approximately 66% to 84% of total daily energy, saturated fat, cholesterol, fiber, total sugar, added sugars, calcium, vitamin D, potassium, and sodium intake are contributed by one of the five categories of processed foods. Clinicians and policy should primarily advise consideration of the energy and nutrient composition of foods, rather than the processing level, when selecting a healthy diet for children. PMID:26633491

Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads

NASA Astrophysics Data System (ADS)

Schilling, K. E.; Arenas Amado, A.; Jones, C. S.; Weber, L. J.

2015-12-01

Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.

Annual contribution of carbon, nitrogen, and phosphorus by migrant Canada geese to a hardwater lake

USGS Publications Warehouse

Manny, Bruce A.; Wetzel, Robert G.; Johnson, W.C.

1975-01-01

Each year more than 6,000 migrant Canada geese (Branta canadensis interior Todd) rest for 3 to 10 days during the months of March, October, November, and December on Wintergreen Lake, a productive 15 ha (33 acre) hardwater lake in the W. K. Kellogg Bird Sanctuary of Michigan State University in southwestern Michigan. For the past six years accurate weekly counts have been made of resident and migrant waterfowl using Wintergreen Lake. During the past four years Wintergreen Lake has been the site of extensive limnological investigations relating nutrient dynamics and primary productivity. These limnological investigations suggested nutrients contributed by migrant Canada geese were the chief cause of hypereutrophic primary productivity conditions in Wintergreen Lake. Until January 1970, the unpredictable habits of wild Canada geese using Wintergreen Lake prevented accurate estimation of nutrients contributed ton the lake in the form of goose feces. An opportunity to measure this source of nutrients was presented on 9 to 11 January 1970 when about 600 late fall migrant Canada geese rested part of three days in a clearly defined area on newly fallen snow covering frozen Wintergreen Lake. During their stay on the lake accurate records were kept of goose numbers, their location on the lake surface, hours spent on the ice and hours spent feeding off the lake. After the geese left on 11 January 1970, a random sampling procedure was used to measure the density of droppings deposited within the area used by the geese on the lake surface.

Nutritional strategies to optimize dairy cattle immunity.

PubMed

Sordillo, L M

2016-06-01

Dairy cattle are susceptible to increased incidence and severity of both metabolic and infectious diseases during the periparturient period. A major contributing factor to increased health disorders is alterations in bovine immune mechanisms. Indeed, uncontrolled inflammation is a major contributing factor and a common link among several economically important infectious and metabolic diseases including mastitis, retained placenta, metritis, displaced abomasum, and ketosis. The nutritional status of dairy cows and the metabolism of specific nutrients are critical regulators of immune cell function. There is now a greater appreciation that certain mediators of the immune system can have a reciprocal effect on the metabolism of nutrients. Thus, any disturbances in nutritional or immunological homeostasis can provide deleterious feedback loops that can further enhance health disorders, increase production losses, and decrease the availability of safe and nutritious dairy foods for a growing global population. This review will discuss the complex interactions between nutrient metabolism and immune functions in periparturient dairy cattle. Details of how either deficiencies or overexposure to macro- and micronutrients can contribute to immune dysfunction and the subsequent development of health disorders will be presented. Specifically, the ways in which altered nutrient metabolism and oxidative stress can interact to compromise the immune system in transition cows will be discussed. A better understanding of the linkages between nutrition and immunity may facilitate the design of nutritional regimens that will reduce disease susceptibility in early lactation cows. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The Consequences of Precipitation Seasonality for Mediterranean-Ecosystem Vegetation of South Africa.

PubMed

Cramer, Michael D; Hoffman, M Timm

2015-01-01

Globally, mediterranean-climate ecosystem vegetation has converged on an evergreen, sclerophyllous and shrubby growth form. The particular aspects of mediterranean-climate regions that contribute to this convergence include summer droughts and relatively nutrient-poor soils. We hypothesised that winter-precipitation implies stressful summer droughts and leaches soils due to greater water availability (i.e. balance between precipitation and potential evapotranspiration; P-PET) during cold periods. We conducted a comparative analysis of normalised difference vegetation indices (NDVI) and edaphic and climate properties across the biomes of South Africa. NDVI was strongly correlated with both precipitation and P-PET (r2 = 0.8). There was no evidence, however, that winter-precipitation reduces NDVI in comparison to similar amounts of summer-precipitation. Base saturation (BS), a measure of soil leaching was, however, negatively related to P-PET (r2 = 0.64). This led to an interaction between P-PET and BS in determining NDVI, indicating the existence of a trade-off between water availability and soil nutrients that enables NDVI to increase with precipitation, despite negative consequences for soil nutrient availability. The mechanism of this trade-off is suggested to be that water increases nutrient accessibility. This implies that along with nutrient-depauperate geologies and long periods of time since glaciation, the winter-precipitation may have contributed to the highly leached status of the soils. Since many of the ecophysiological characteristics of mediterranean-ecosystem flora are associated with low nutrient availabilities (e.g. evergreen foliage, sclerophylly, cluster roots), we conclude that mediterranean-climates promote convergence of growth-forms in these regions through high leaching capacity.

The Consequences of Precipitation Seasonality for Mediterranean-Ecosystem Vegetation of South Africa

PubMed Central

2015-01-01

Globally, mediterranean-climate ecosystem vegetation has converged on an evergreen, sclerophyllous and shrubby growth form. The particular aspects of mediterranean-climate regions that contribute to this convergence include summer droughts and relatively nutrient-poor soils. We hypothesised that winter-precipitation implies stressful summer droughts and leaches soils due to greater water availability (i.e. balance between precipitation and potential evapotranspiration; P–PET) during cold periods. We conducted a comparative analysis of normalised difference vegetation indices (NDVI) and edaphic and climate properties across the biomes of South Africa. NDVI was strongly correlated with both precipitation and P–PET (r2 = 0.8). There was no evidence, however, that winter-precipitation reduces NDVI in comparison to similar amounts of summer-precipitation. Base saturation (BS), a measure of soil leaching was, however, negatively related to P–PET (r2 = 0.64). This led to an interaction between P–PET and BS in determining NDVI, indicating the existence of a trade-off between water availability and soil nutrients that enables NDVI to increase with precipitation, despite negative consequences for soil nutrient availability. The mechanism of this trade-off is suggested to be that water increases nutrient accessibility. This implies that along with nutrient-depauperate geologies and long periods of time since glaciation, the winter-precipitation may have contributed to the highly leached status of the soils. Since many of the ecophysiological characteristics of mediterranean-ecosystem flora are associated with low nutrient availabilities (e.g. evergreen foliage, sclerophylly, cluster roots), we conclude that mediterranean-climates promote convergence of growth-forms in these regions through high leaching capacity. PMID:26650081

Periconceptional nutrient intakes and risks of neural tube defects in California.

PubMed

Carmichael, Suzan L; Yang, Wei; Shaw, Gary M

2010-08-01

This study investigated the association of neural tube defects (NTDs) with maternal periconceptional intake of folic acid-containing supplements and dietary nutrients, including folate, among deliveries that occurred after folic acid fortification in selected California counties. The population-based case-control study included fetuses and live born infants with spina bifida (189) or anencephaly (141) and 625 nonmalformed, live born controls delivered from 1999 to 2003. Mothers reported supplement use during telephone interviews, which included a 107-item food frequency questionnaire. For dietary nutrients, intakes <25th, 25th to <75th (reference), and > or =75th percentile were compared, based on control distributions. After adjustment for potential confounders, any versus no supplement intake resulted in ORs of 0.8 (95% CI, 0.5-1.3) for anencephaly and 0.8 (95% CI, 0.6-1.2) for spina bifida. After stratification by maternal intake of vitamin supplements, most factors in the glycemic pathway were not associated with either NTD, with the exception of low levels of fructose and glucose that were significantly associated with anencephaly. Some nutrients that contribute to one-carbon metabolism showed lowered risks (folate, riboflavin, vitamins B(6) and B(12)); others did not (choline, methionine, zinc). Antioxidant nutrients tended to be associated with lowered risks (vitamins C, E, A, beta-carotene, lutein). Mothers' intake of vitamin supplements was modestly if at all associated with a lowered risk of NTDs. Dietary intake of several nutrients contributing to one-carbon metabolism and oxidative stress were associated with reduced NTD risk.

Irrigation water acidification to neutralize alkalinity for nursery crop production: Substrate pH, electrical conductivity, and nutrient concentrations; and plant nutrition and growth

USDA-ARS?s Scientific Manuscript database

Liming agents (LA) in irrigation water, typically associated with carbonates and bicarbonates of calcium (Ca) and magnesium (Mg), contribute to water alkalinity. Repeated application of LA to container crops can cause media-solution pH to rise overtime, that uncorrected, can lead to a nutrient avail...

Stump sprouting of northern pin oak on nutrient-poor sandy soils in central Wisconsin

Treesearch

Kevin M. Schwartz; Michael C. Demchik

2013-01-01

Coppice with two to three reserve trees per acre is the generally accepted practice (GAP) for rotating oak stands on nutrient-poor, sandy sites (colloquially called "scrub oak sites") in Wisconsin. The future stocking of the stand is therefore dependent predominantly on stump sprouts with varying levels of contribution from advance regeneration. Two groups of...

Ecological consequences of invasion across the freshwater-marine transition in a warming world.

PubMed

Crespo, Daniel; Solan, Martin; Leston, Sara; Pardal, Miguel A; Dolbeth, Marina

2018-02-01

The freshwater-marine transition that characterizes an estuarine system can provide multiple entry options for invading species, yet the relative importance of this gradient in determining the functional contribution of invading species has received little attention. The ecological consequences of species invasion are routinely evaluated within a freshwater versus marine context, even though many invasive species can inhabit a wide range of salinities. We investigate the functional consequences of different sizes of Corbicula fluminea -an invasive species able to adapt to a wide range of temperatures and salinity-across the freshwater-marine transition in the presence versus absence of warming. Specifically, we characterize how C. fluminea affect fluid and particle transport, important processes in mediating nutrient cycling (NH 4 -N, NO 3 -N, PO 4 -P). Results showed that sediment particle reworking (bioturbation) tends to be influenced by size and to a lesser extent, temperature and salinity; nutrient concentrations are influenced by different interactions between all variables (salinity, temperature, and size class). Our findings demonstrate the highly context-dependent nature of the ecosystem consequences of invasion and highlight the potential for species to simultaneously occupy multiple components of an ecosystem. Recognizing of this aspect of invasibility is fundamental to management and conservation efforts, particularly as freshwater and marine systems tend to be compartmentalized rather than be treated as a contiguous unit. We conclude that more comprehensive appreciation of the distribution of invasive species across adjacent habitats and different seasons is urgently needed to allow the true extent of biological introductions, and their ecological consequences, to be fully realized.

Dairy in a sustainable diet: a question of balance.

PubMed

van Hooijdonk, Toon; Hettinga, Kasper

2015-08-01

The demand for dairy products is growing rapidly, especially in emerging markets. Dairy products are nutrient rich and, therefore, an important food group for ensuring nutrient security in the future. In many countries, dairy contributes significantly to nutrient intake. Meta-analyses have shown that consumption of dairy may reduce the risk of chronic diseases and thereby lower healthcare costs. Milk production and processing contribute to greenhouse gas emissions, estimated at 2.7% (cradle-to-retail) of the world's total. Evaluating the position of dairy in the diet should take into account the impact of both nutritional and environmental factors. Local conditions are also important; in many parts of the world, the cow is an efficient converter of human-inedible resources into nutrient-dense food. Increased productivity of cows is a decisive factor in realizing sufficient milk production with optimal resource efficiency and minimal greenhouse gas emission. Models that optimize total diets, rather than individual food products, for their nutritional and environmental impact are the preferred approach for developing realistic alternative consumption strategies. © The Author(s) 2015. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

The effects of kinds of lumus and the storage period on the quality of patin wadi based on the results of nutrient tests

NASA Astrophysics Data System (ADS)

Dewi, Indah Sari; Hastuti, Utami Sri; Lestari, Umi; Suwono, Hadi

2017-05-01

Wadi is the processed product of fish, due to local knowledge of the Dayak community, made of fresh fish with salt and lumus. The efforts to increase the quality of wadi as a kind of food were based on local knowledge, and are still ongoing. It is one of the ways to conserve wadi existence in the middle of the modern culture. It is important to add a variety of spices in suitable amounts as the innovation in producing wadi. People process wadi by using lumus made of rice and corn. Lumus gives a special taste and aroma t o wadi, furthermore, the effects of kinds of lumus and their concentrates, and the storage period on the nutrients of wadi are not known yet. This research used patin fish (Pangasius sp), white rice (Oryza sativa), white sticky rice (Oryza sativa var.glutinous), and corn (Zea mays) as the kinds of lumus. Each kind of lumus is mixed with fresh patin fish in different concentrations: 15%, 25% and 35%. The results of nutrient tests include measures of protein, carbohydrate, and fat, and show that patin which has been processed into wadi has more nutrients than fresh patin. The storage period and the varying concentrates of lumus effect the level of nutrients in patin wadi.

Is income breeding an appropriate construct for waterfowl?

USGS Publications Warehouse

Janke, Adam K.; Anteau, Michael J.; Markl, Nicholas; Stafford, Joshua D.

2015-01-01

Breeding birds use a range of nutrient accumulation and allocation strategies to meet the nutritional demands of clutch formation and incubation. On one end of the spectrum, capital breeders use stored nutrients acquired prior to clutch formation and incubation to sustain metabolism during reproduction, while on the opposite end, income breeders derive nutrients solely from exogenous sources on the breeding grounds. Blue-winged Teal (Anas discors) are an ideal candidate to test for adoption of an income strategy among migratory waterfowl because of their small body size, temperate breeding range, and timing of reproduction relative to pulses in nutrient availability within breeding habitats. We collected migrating and pre-breeding Blue-winged Teal (n = 110) during the warmest spring in over a century in the southern edge of the species’ breeding range, which produced ideal conditions to test for adoption of an income breeding strategy among migratory waterfowl. Regression analyses revealed that females accumulated protein and fat reserves early in follicle development and appeared to mobilize at least some reserves coincident with the onset of clutch formation. Accumulation and subsequent mobilization of nutrient reserves was inconsistent with adherence to an income breeding strategy and suggested breeding Blue-winged Teal used capital (albeit locally acquired) for reproduction. Our results add to existing knowledge on the ubiquity of endogenous nutrient reserve accumulation prior to and during reproduction by waterfowl, perhaps suggesting endogenous nutrient reserves are universally used for clutch formation or incubation to some degree. If indeed Blue-winged Teal and other waterfowl universally use capital for breeding, research and conservation efforts should shift from evaluating whether an income breeding strategy is used and focus on when and where necessary capital is acquired prior to clutch formation.

Predatory dipteran larva contributes to nutrient sequestration in a carnivorous pitcher plant.

PubMed

Lam, Weng Ngai; Lim, Robyn Jing Ying; Wong, Shi Hong; Tan, Hugh Tiang Wah

2018-03-01

The fluids of Nepenthes pitcher plants are habitats to many specialized animals known as inquilines, which facilitate the conversion of prey protein into pitcher-absorbable nitrogen forms such as ammonium. Xenoplatyura beaveri (Diptera: Mycetophilidae) is a predatory dipteran inquiline that inhabits the pitchers of Nepenthes ampullaria Larvae of X. beaveri construct sticky webs over the fluid surface of N. ampullaria to ensnare emerging adult dipteran inquilines. However, the interaction between X. beaveri and its host has never been examined before, and it is not known if X. beaveri can contribute to nutrient sequestration in N. ampullaria. Xenoplatyura beaveri individuals were reared in artificial pitchers in the laboratory on a diet of emergent Tripteroides tenax mosquitoes, and the ammonium concentration of the pitcher fluids was measured over time. Fluid ammonium concentration in tubes containing X. beaveri was significantly greater than those of the controls. Furthermore, fluid ammonium concentrations increased greatly after X. beaveri larvae metamorphosed, although the cause of this increase could not be identified. Our results show that a terrestrial, inquiline predator can contribute significantly to nutrient sequestration in the phytotelma it inhabits, and suggest that this interaction has a net mutualistic outcome for both species. © 2018 The Author(s).

100% citrus juice: Nutritional contribution, dietary benefits, and association with anthropometric measures.

PubMed

Rampersaud, Gail C; Valim, M Filomena

2017-01-02

Citrus juices such as 100% orange (OJ) and grapefruit juice (GJ) are commonly consumed throughout the world. This review examines the contributions of OJ and GJ to nutrient intake, diet quality, and fruit intake, and supports citrus juices as nutrient-dense beverages. This review also explores the research examining associations between OJ and GJ intake and anthropometric measures. Citrus juices are excellent sources of vitamin C and contribute other key nutrients such as potassium, folate, magnesium, and vitamin A. OJ intake has been associated with better diet quality in children and adults. OJ intake has not been associated with adverse effects on weight or other body measures in observational studies in children and adults. In adults, some observational studies report more favorable body mass index or body measure parameters in OJ consumers compared to nonconsumers. Intervention studies in adults report no negative impacts of OJ or GJ consumption on anthropometric measures, although these measures were typically not the primary outcomes examined in the studies. Moderate consumption of citrus juices may provide meaningful nutritional and dietary benefits and do not appear to negatively impact body weight, body composition, or other anthropometric measures in children and adults.

Competition for light causes plant biodiversity loss after eutrophication.

PubMed

Hautier, Yann; Niklaus, Pascal A; Hector, Andy

2009-05-01

Human activities have increased the availability of nutrients in terrestrial and aquatic ecosystems. In grasslands, this eutrophication causes loss of plant species diversity, but the mechanism of this loss has been difficult to determine. Using experimental grassland plant communities, we found that addition of light to the grassland understory prevented the loss of biodiversity caused by eutrophication. There was no detectable role for competition for soil resources in diversity loss. Thus, competition for light is a major mechanism of plant diversity loss after eutrophication and explains the particular threat of eutrophication to plant diversity. Our conclusions have implications for grassland management and conservation policy and underscore the need to control nutrient enrichment if plant diversity is to be preserved.

Impacts of transportation infrastructure on storm water and surfaces waters in Chittenden County, Vermont, USA.

DOT National Transportation Integrated Search

2014-06-01

Transportation infrastructure is a major source of stormwater runoff that can alter hydrology and : contribute significant loading of nutrients, sediment, and other pollutants to surface waters. These : increased loads can contribute to impairment of...

Interactive effects of climate change with nutrients, mercury, and freshwater acidification on key taxa in the North Atlantic Landscape Conservation Cooperative region.

PubMed

Pinkney, Alfred E; Driscoll, Charles T; Evers, David C; Hooper, Michael J; Horan, Jeffrey; Jones, Jess W; Lazarus, Rebecca S; Marshall, Harold G; Milliken, Andrew; Rattner, Barnett A; Schmerfeld, John; Sparling, Donald W

2015-07-01

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public-private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using a case study approach, we focused on 3 stressors with sufficient NA LCC region-specific information for an informed discussion. We describe GCC interactions with a contaminant (Hg) and 2 complex environmental phenomena-freshwater acidification and eutrophication. We also prepared taxa case studies on GCC- and GCC-contaminant/nutrient/process effects on amphibians and freshwater mussels. Several avian species of high conservation concern have blood Hg concentrations that have been associated with reduced nesting success. Freshwater acidification has adversely affected terrestrial and aquatic ecosystems in the Adirondacks and other areas of the region that are slowly recovering due to decreased emissions of N and sulfur oxides. Eutrophication in many estuaries within the region is projected to increase from greater storm runoff and less denitrification in riparian wetlands. Estuarine hypoxia may be exacerbated by increased stratification. Elevated water temperature favors algal species that produce harmful algal blooms (HABs). In several of the region's estuaries, HABs have been associated with bird die-offs. In the NA LCC region, amphibian populations appear to be declining. Some species may be adversely affected by GCC through higher temperatures and more frequent droughts. GCC may affect freshwater mussel populations via altered stream temperatures and increased sediment loading during heavy storms. Freshwater mussels are sensitive to un-ionized ammonia that more toxic at higher temperatures. We recommend studying the interactive effects of GCC on generation and bioavailability of methylmercury and how GCC-driven shifts in bird species distributions will affect avian exposure to methylmercury. Research is needed on how decreases in acid deposition concurrent with GCC will alter the structure and function of sensitive watersheds and surface waters. Studies are needed to determine how GCC will affect HABs and avian disease, and how more severe and extensive hypoxia will affect fish and shellfish populations. Regarding amphibians, we suggest research on 1) thermal tolerance and moisture requirements of species of concern, 2) effects of multiple stressors (temperature, desiccation, contaminants, nutrients), and 3) approaches to mitigate impacts of increased temperature and seasonal drought. We recommend studies to assess which mussel species and populations are vulnerable and which are resilient to rising stream temperatures, hydrological shifts, and ionic pollutants, all of which are influenced by GCC. © 2015 SETAC.

Interactive effects of climate change with nutrients, mercury, and freshwater acidification on key taxa in the North Atlantic Landscape Conservation Cooperative region

USGS Publications Warehouse

Pinkney, Alfred E.; Driscoll, Charles T.; Evers, David C.; Hooper, Michael J.; Horan, Jeffrey; Jones, Jess W.; Lazarus, Rebecca S.; Marshall, Harold G.; Milliken, Andrew; Rattner, Barnett A.; Schmerfeld, John J.; Sparling, Donald W.

2015-01-01

The North Atlantic Landscape Conservation Cooperative LCC (NA LCC) is a public–private partnership that provides information to support conservation decisions that may be affected by global climate change (GCC) and other threats. The NA LCC region extends from southeast Virginia to the Canadian Maritime Provinces. Within this region, the US National Climate Assessment documented increases in air temperature, total precipitation, frequency of heavy precipitation events, and rising sea level, and predicted more drastic changes. Here, we synthesize literature on the effects of GCC interacting with selected contaminant, nutrient, and environmental processes to adversely affect natural resources within this region. Using a case study approach, we focused on 3 stressors with sufficient NA LCC region-specific information for an informed discussion. We describe GCC interactions with a contaminant (Hg) and 2 complex environmental phenomena—freshwater acidification and eutrophication. We also prepared taxa case studies on GCC- and GCC-contaminant/nutrient/process effects on amphibians and freshwater mussels. Several avian species of high conservation concern have blood Hg concentrations that have been associated with reduced nesting success. Freshwater acidification has adversely affected terrestrial and aquatic ecosystems in the Adirondacks and other areas of the region that are slowly recovering due to decreased emissions of N and sulfur oxides. Eutrophication in many estuaries within the region is projected to increase from greater storm runoff and less denitrification in riparian wetlands. Estuarine hypoxia may be exacerbated by increased stratification. Elevated water temperature favors algal species that produce harmful algal blooms (HABs). In several of the region's estuaries, HABs have been associated with bird die-offs. In the NA LCC region, amphibian populations appear to be declining. Some species may be adversely affected by GCC through higher temperatures and more frequent droughts. GCC may affect freshwater mussel populations via altered stream temperatures and increased sediment loading during heavy storms. Freshwater mussels are sensitive to un-ionized ammonia that more toxic at higher temperatures. We recommend studying the interactive effects of GCC on generation and bioavailability of methylmercury and how GCC-driven shifts in bird species distributions will affect avian exposure to methylmercury. Research is needed on how decreases in acid deposition concurrent with GCC will alter the structure and function of sensitive watersheds and surface waters. Studies are needed to determine how GCC will affect HABs and avian disease, and how more severe and extensive hypoxia will affect fish and shellfish populations. Regarding amphibians, we suggest research on 1) thermal tolerance and moisture requirements of species of concern, 2) effects of multiple stressors (temperature, desiccation, contaminants, nutrients), and 3) approaches to mitigate impacts of increased temperature and seasonal drought. We recommend studies to assess which mussel species and populations are vulnerable and which are resilient to rising stream temperatures, hydrological shifts, and ionic pollutants, all of which are influenced by GCC.

What's Upstream? GIS's critical role in developing nutrient ...

EPA Pesticide Factsheets

Eutrophication due to excess levels of nitrogen and phosphorus can seriously impair ecological function in estuaries. Protective criteria for nutrients are difficult to establish because the source can vary spatially and seasonally, originate either from the watershed or the ocean, and be natural or anthropogenic. GIS tools and processes can help in developing nutrient criteria by establishing reference conditions representative of natural background nutrient levels. Along the Oregon Coast in the Pacific Northwest, the primary source of nutrients in the wet season (November-April) is generally riverine. We delineated and extracted explicit spatial data from watersheds upstream of riverine water quality monitoring stations for parametric comparison to recorded nutrient levels. The SPARROW model (Wise and Johnson, 2011) was used to estimate relative contributions of nutrient sources at each station. Both raster and vector spatial data were used and include land use / land cover, demography, geology, terrain, precipitation and forest type. The relationships of nutrients to spatial data were then explored as an approach to establishing the reference expectation. The abstract introduces Geographic Information Systems (GIS) tools and processes employed for research conducted under the Safe and Sustainable Water Resources (SSWR) Task 2.3A, entitled “Nutrient Management for Sustainability of Aquatic Ecosystems.” One of the goals of the EPA Office of Water is to

Adaptive management for soil ecosystem services.

PubMed

Birgé, Hannah E; Bevans, Rebecca A; Allen, Craig R; Angeler, David G; Baer, Sara G; Wall, Diana H

2016-12-01

Ecosystem services provided by soil include regulation of the atmosphere and climate, primary (including agricultural) production, waste processing, decomposition, nutrient conservation, water purification, erosion control, medical resources, pest control, and disease mitigation. The simultaneous production of these multiple services arises from complex interactions among diverse aboveground and belowground communities across multiple scales. When a system is mismanaged, non-linear and persistent losses in ecosystem services can arise. Adaptive management is an approach to management designed to reduce uncertainty as management proceeds. By developing alternative hypotheses, testing these hypotheses and adjusting management in response to outcomes, managers can probe dynamic mechanistic relationships among aboveground and belowground soil system components. In doing so, soil ecosystem services can be preserved and critical ecological thresholds avoided. Here, we present an adaptive management framework designed to reduce uncertainty surrounding the soil system, even when soil ecosystem services production is not the explicit management objective, so that managers can reach their management goals without undermining soil multifunctionality or contributing to an irreversible loss of soil ecosystem services. Copyright © 2016. Published by Elsevier Ltd.

Abundance and local-scale processes contribute to multi-phyla gradients in global marine diversity

PubMed Central

Edgar, Graham J.; Alexander, Timothy J.; Lefcheck, Jonathan S.; Bates, Amanda E.; Kininmonth, Stuart J.; Thomson, Russell J.; Duffy, J. Emmett; Costello, Mark J.; Stuart-Smith, Rick D.

2017-01-01

Among the most enduring ecological challenges is an integrated theory explaining the latitudinal biodiversity gradient, including discrepancies observed at different spatial scales. Analysis of Reef Life Survey data for 4127 marine species at 2406 coral and rocky sites worldwide confirms that the total ecoregion richness peaks in low latitudes, near +15°N and −15°S. However, although richness at survey sites is maximal near the equator for vertebrates, it peaks at high latitudes for large mobile invertebrates. Site richness for different groups is dependent on abundance, which is in turn correlated with temperature for fishes and nutrients for macroinvertebrates. We suggest that temperature-mediated fish predation and herbivory have constrained mobile macroinvertebrate diversity at the site scale across the tropics. Conversely, at the ecoregion scale, richness responds positively to coral reef area, highlighting potentially huge global biodiversity losses with coral decline. Improved conservation outcomes require management frameworks, informed by hierarchical monitoring, that cover differing site- and regional-scale processes across diverse taxa, including attention to invertebrate species, which appear disproportionately threatened by warming seas. PMID:29057321

Using the nutrient ratio NO/PO as a tracer of continental shelf waters in the central Arctic Ocean

NASA Astrophysics Data System (ADS)

Wilson, Cara; Wallace, Douglas W. R.

1990-12-01

Historical nitrate, phosphate, and dissolved oxygen data from the central Arctic Ocean are examined with particular emphasis on the conservative parameters NO (9 * NO3 + O2) and PO (135 * PO4 + O2). The NO/PO ratio is shown to increase with depth in the Canada Basin, being ˜0.78 in Surface and Upper Halocline Waters and ˜1.0 in the Atlantic Layer and Deep Waters. Lower Halocline Water is marked by NO and PO minima and intermediate NO/PO. NO/PO ratios from the Arctic shelf seas are examined to determine possible source regions for the various water masses. The NO/PO ratio of Canada Basin Deep Water implies an upper bound of ˜11% shelf water contribution to this water mass. A slight oxygen maximum core in the Lower Halocline Water is identified at a salinity of S = 34.5 in the vicinity of the Alpha Ridge. This core appears to be diminished by diapycnal mixing and does not extend into the Beaufort Gyre.

Land use, macroalgae, and a tumor-forming disease in marine turtles.

PubMed

Van Houtan, Kyle S; Hargrove, Stacy K; Balazs, George H

2010-09-29

Wildlife diseases are an increasing concern for endangered species conservation, but their occurrence, causes, and human influences are often unknown. We analyzed 3,939 records of stranded Hawaiian green sea turtles (Chelonia mydas) over 28 years to understand fibropapillomatosis, a tumor-forming disease linked to a herpesvirus. Turtle size is a consistent risk factor and size-standardized models revealed considerable spatial and temporal variability. The disease peaked in some areas in the 1990s, in some regions rates remained constant, and elsewhere rates increased. Land use, onshore of where the turtles feed, may play a role. Elevated disease rates were clustered in watersheds with high nitrogen-footprints; an index of natural and anthropogenic factors that affect coastal eutrophication. Further analysis shows strong epidemiological links between disease rates, nitrogen-footprints, and invasive macroalgae and points to foraging ecology. These turtles now forage on invasive macroalgae, which can dominate nutrient rich waters and sequester environmental N in the amino acid arginine. Arginine is known to regulate immune activity, promote herpesviruses, and contribute to tumor formation. Our results have implications for understanding diseases in aquatic organisms, eutrophication, herpesviruses, and tumor formation.

Abundance and local-scale processes contribute to multi-phyla gradients in global marine diversity.

PubMed

Edgar, Graham J; Alexander, Timothy J; Lefcheck, Jonathan S; Bates, Amanda E; Kininmonth, Stuart J; Thomson, Russell J; Duffy, J Emmett; Costello, Mark J; Stuart-Smith, Rick D

2017-10-01

Among the most enduring ecological challenges is an integrated theory explaining the latitudinal biodiversity gradient, including discrepancies observed at different spatial scales. Analysis of Reef Life Survey data for 4127 marine species at 2406 coral and rocky sites worldwide confirms that the total ecoregion richness peaks in low latitudes, near +15°N and -15°S. However, although richness at survey sites is maximal near the equator for vertebrates, it peaks at high latitudes for large mobile invertebrates. Site richness for different groups is dependent on abundance, which is in turn correlated with temperature for fishes and nutrients for macroinvertebrates. We suggest that temperature-mediated fish predation and herbivory have constrained mobile macroinvertebrate diversity at the site scale across the tropics. Conversely, at the ecoregion scale, richness responds positively to coral reef area, highlighting potentially huge global biodiversity losses with coral decline. Improved conservation outcomes require management frameworks, informed by hierarchical monitoring, that cover differing site- and regional-scale processes across diverse taxa, including attention to invertebrate species, which appear disproportionately threatened by warming seas.

Effects of anthropogenic activities on chemical contamination within the Grand Canal, China.

PubMed

Wang, Xiaolong; Han, Jingyi; Xu, Ligang; Gao, Junfeng; Zhang, Qi

2011-06-01

Contamination of nutrients and heavy metals within aquatic system is of great concern due to its potential impact on human and animal health. The Grand Canal of China, the largest artificial river in the world, is of great importance in supplying water resource, transporting cargo, and recreating resident, as well as great historical heritage. This study assessed and examined the impact of human activities on characters of contamination distribution within the section of the Canal in Taihu watershed. Physicochemical parameters of surface water quality were determined monthly from the year 2004 to 2006 at 11 sites that were influenced by different anthropogenic activities along the Canal. Moreover, contaminations at surface sediments (20 cm) at the same locations were also analyzed in September 2006. Results showed that the Canal had been seriously polluted, which was characterized with high spatial variations in contaminations distribution. The sites influenced mainly by industry and urbanization showed higher contents of nutrients and lower levels of dissolve oxygen than other sites. Concentrations of nitrogen at all studied sites exceeded the worst level of surface water quality according to the National Criterion of Surface Water Quality, China, with the average values varying from 2.27 to 10.34 mg/L. Furthermore, the site influenced mainly by industry (i.e., Site 4) presented the highest contents of cadmium (3.453 mg/kg), chromium (196.87 mg/kg), nickel (87.12 mg/kg), zinc (381.8 mg/kg), and copper (357.32 mg/kg). While sites in vicinity to cities had presented relatively higher contents of metals, especially for the site located downstream of Changzhou City (Site 3) had presented the highest contents of mercury (1.64 mg/kg) and lead (197.62 mg/kg). Copper at Sites 2 to 6, Nickel at Sites 2 to 9 except for Site 7, chromium, lead, and zinc at Sites 3 to 6 had exceeded New York State Department of Environmental Conservation (NYSDEC) Severe Effect Level (SEL). By multivariate statistical, nutrient variables, companied with V-phen, had contributed the most variation of water quality, while nutrient and metals had explained the most part of total variance of contaminations in sediment. This study indicated that the canal had been polluted severely and urgently need to control.

Atmospheric dust in modern soil on aeolian sandstone, Colorado Plateau (USA): Variation with landscape position and contribution to potential plant nutrients

USGS Publications Warehouse

Reynolds, R.; Neff, J.; Reheis, M.; Lamothe, P.

2006-01-01

Rock-derived nutrients in soils originate from both local bedrock and atmospheric dust, including dust from far-distant sources. Distinction between fine particles derived from local bedrock and from dust provides better understanding of the landscape-scale distribution and abundance of soil nutrients. Sandy surficial deposits over dominantly sandstone substrates, covering vast upland areas of the central Colorado Plateau, typically contain 5-40% silt plus clay, depending on geomorphic setting and slope (excluding drainages and depressions). Aeolian dust in these deposits is indicated by the presence of titanium-bearing magnetite grains that are absent in the sedimentary rocks of the region. Thus, contents of far-traveled aeolian dust can be estimated from magnetic properties that primarily reflect magnetite content, such as isothermal remanent magnetization (IRM). Isothermal remanent magnetization was measured on bulk sediment samples taken along two transects in surficial sediment down gentle slopes away from sandstone headwalls. One transect was in undisturbed surficial sediment, the other in a setting that was grazed by domestic livestock until 1974. Calculation of far-traveled dust contents of the surficial deposits is based on measurements of the magnetic properties of rock, surficial deposits, and modern dust using a binary mixing model. At the undisturbed site, IRM-based calculations show a systematic down-slope increase in aeolian dust (ranging from 2% to 18% of the surface soil mass), similar to the down-slope increase in total fines (18-39% of surface soil mass). A combination of winnowing by wind during the past and down-slope movement of sediment likely accounts for the modern distribution of aeolian dust and associated nutrients. At the previously grazed site, dust also increases down slope (5-11%) in sediment with corresponding abundances of 13-25% fines. Estimates of the contributions of aeolian dust to the total soil nutrients range widely, depending on assumptions about grain-size partitioning of potential nutrients in weathered bedrock. Nevertheless, aeolian dust is important for this setting, contributing roughly 40-80% of the rock-derived nutrient stocks (P, K, Na, Mn, Zn, and Fe) in uppermost soil over most of the sampled slope at the undisturbed site, which shows no evidence of recent wind erosion. ?? 2005 Elsevier B.V. All rights reserved.

Energy conservation in solid waste management in Bangladesh

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rahman, M.H.

1994-12-31

Recycling of solid wastes has a characteristic pattern in Bangladesh in the context of the general habits and socio-economic status of the population. Extensive resource recovery from solid wastes is being carried out at various stages of disposal. The characteristics of solid wastes at the final disposal site indicate that they contain more than 90% of organic wastes. Hence, anaerobic digestion of these wastes serves a dual purpose in the conservation of energy and of valuable crop nutrients for efficient recycling especially in an agriculture-based economy. This also improves overall environmental sanitation and reduces environmental degradation. In this paper, differentmore » recycling and reuse options for solid wastes are critically discussed from the energy recovery and energy conservation point of view. It has been shown that the resource recovery from solid wastes would minimize the energy problem and would lead to a net reduction of greenhouse gases, particularly in the developing world.« less

Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America.

PubMed

Eads, David A; Biggins, Dean E

2015-08-01

Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research. © 2015 Society for Conservation Biology.

Using landscape limnology to classify freshwater ecosystems for multi-ecosystem management and conservation

USGS Publications Warehouse

Soranno, Patricia A.; Cheruvelil, Kendra Spence; Webster, Katherine E.; Bremigan, Mary T.; Wagner, Tyler; Stow, Craig A.

2010-01-01

Governmental entities are responsible for managing and conserving large numbers of lake, river, and wetland ecosystems that can be addressed only rarely on a case-by-case basis. We present a system for predictive classification modeling, grounded in the theoretical foundation of landscape limnology, that creates a tractable number of ecosystem classes to which management actions may be tailored. We demonstrate our system by applying two types of predictive classification modeling approaches to develop nutrient criteria for eutrophication management in 1998 north temperate lakes. Our predictive classification system promotes the effective management of multiple ecosystems across broad geographic scales by explicitly connecting management and conservation goals to the classification modeling approach, considering multiple spatial scales as drivers of ecosystem dynamics, and acknowledging the hierarchical structure of freshwater ecosystems. Such a system is critical for adaptive management of complex mosaics of freshwater ecosystems and for balancing competing needs for ecosystem services in a changing world.

Zinc: an essential but elusive nutrient123

PubMed Central

King, Janet C

2011-01-01

Zinc is essential for multiple aspects of metabolism. Physiologic signs of zinc depletion are linked with diverse biochemical functions rather than with a specific function, which makes it difficult to identify biomarkers of zinc nutrition. Nutrients, such as zinc, that are required for general metabolism are called type 2 nutrients. Protein and magnesium are examples of other type 2 nutrients. Type 1 nutrients are required for one or more specific functions: examples include iron, vitamin A, iodine, folate, and copper. When dietary zinc is insufficient, a marked reduction in endogenous zinc loss occurs immediately to conserve the nutrient. If zinc balance is not reestablished, other metabolic adjustments occur to mobilize zinc from small body pools. The location of those pools is not known, but all cells probably have a small zinc reserve that includes zinc bound to metallothionein or zinc stored in the Golgi or in other organelles. Plasma zinc is also part of this small zinc pool that is vulnerable to insufficient intakes. Plasma zinc concentrations decline rapidly with severe deficiencies and more moderately with marginal depletion. Unfortunately, plasma zinc concentrations also decrease with a number of conditions (eg, infection, trauma, stress, steroid use, after a meal) due to a metabolic redistribution of zinc from the plasma to the tissues. This redistribution confounds the interpretation of low plasma zinc concentrations. Biomarkers of metabolic zinc redistribution are needed to determine whether this redistribution is the cause of a low plasma zinc rather than poor nutrition. Measures of metallothionein or cellular zinc transporters may fulfill that role. PMID:21715515