Skip to main content
Advanced Search

Filters: Tags: nutrient cycling (X)

36 results (18ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
The most common system responses attributed to microfloral grazers (protozoa, nematodes, microarthropods) in the literature are increased plant growth, increased N uptake by plants, decreased or increased bacterial populations, increased CO2 evolution, increased N and P mineralization, and increased substrate utilization. Based on this evidence in the literature, a conceptual model was proposed in which microfloral grazers were considered as separate state variables. To help evaluate the model, the effects of microbivorous nematodes on microbial growth, nutrient cycling, plant growth, and nutrient uptake were examined with reference to activities within and outside of the rhizosphere. Blue grama grass (Bouteloua...
thumbnail
Lake Powell retains most of the phosphorus that it receives, leading to downstream phosphorus limitation. These data were compiled to examine controls on phosphorus cycling below Lake Powell in the Colorado River and from storm inputs from the Paria River. Objectives of our study were to determine how several forms of phosphorus, both organic and inorganic, were cycled under varying dissolved oxygen concentrations and pH, reflecting the range of values observed in the river over the years. These data represent nitrogen, phosphorus, calcium, and carbon concentrations, water quality parameters (pH, dissolved oxygen, temperature), sediment composition, total protein, and extracellular enzyme activity (alkaline phosphatase)....
Categories: Data; Tags: Aquatic Biology, Arizona, Colorado River, Ecology, Geochemistry, All tags...
thumbnail
This dataset is a single comma-delimited text file (.csv). Data include the name of lakes where samples were obtained, soil pH, electrical conductivity (EC), water content (VWC), and bulk density (BD) of soil core samples within organic soil horizon in lake-margin wetland plant communities.
Interspecific variation in polyphenol production by plants has been interpreted in terms of defense against herbivores. Several recent lines of evidence suggest that polyphenols also influence the pools and fluxes of inorganic and organic soil nutrients. Such effects could have far-ranging consequences for nutrient competition among and between plants and microbes, and for ecosystem nutrient cycling and retention. The significance of polyphenols for nutrient cycling and plant productivity is still uncertain, but it could provide an alternative or complementary explanation for the variability in polyphenol production by plants. Published in Trends in Ecology & Evolution, volume 15, issue 6, on pages 238 - 243, in...
The recent upsurge in research attention to aeolian dust has shown that dust transport systems operate on very large spatial and temporal scales, and involve much larger quantities of sediment than was previously realized. An inevitable consequence of this is that researchers from a range of neighbouring disciplines, including ecology, are beginning to realize that this new knowledge has important implications for their study areas. In the present paper, we examine the ecological implications (real and potential) of this expanding knowledge of dust transport systems, with a particular emphasis upon the Australian dust transport system. We track these ecological effects from source to sink. At source, wind erosion–soil–vegetation...
thumbnail
This dataset is a single comma-delimited text file (.csv). Data include the name of lakes where samples were obtained, soil core dimensions, bulk density, and carbon/nitrogen content of soil core samples within the organic soil horizon in lake-margin wetland plant communities.
thumbnail
These data were compiled for a restoration experiment testing the regenerative and functional response of biocrust inoculum reintroduced to a field setting. Regenerative traits measured included measurements of biocrust cover, chlorophyll content, and the roughness of the soil surface. Functional traits measured included nutrient cycling and soil stability. Additionally, these data were compiled for an experiment testing how much soil is lost from different types of ground cover. The data collected was related to ground cover and the amount of soil lost from plots through time. These data were used to inform the conclusions drawn in the accompanying manuscript.
thumbnail
Geochemical data were obtained to investigate the fate and transport of nitrogen in a subterranean estuary near East Falmouth, Massachusetts. The goal of this investigation was to assess nitrogen attenuation in the aquifer under the Eel River Estuary and the adjacent peninsula that was densely populated with residences having septic systems and legacy cesspool inputs of inorganic nitrogen. This estuary is one of many small embayments on Cape Cod where nutrient enrichment can lead to eutrophication and is a major concern for water-quality impairment. Groundwater water-quality data were collected from 3 transects from a total of 27 locations that were sampled between November 2015 and October 2016. Samples were...
We explore empirical and theoretical evidence for the functional significance of plant-litter diversity and the extraordinary high diversity of decomposer organisms in the process of litter decomposition and the consequences for biogeochemical cycles. Potential mechanisms for the frequently observed litter-diversity effects on mass loss and nitrogen dynamics include fungi-driven nutrient transfer among litter species, inhibition or stimulation of microorganisms by specific litter compounds, and positive feedback of soil fauna due to greater habitat and food diversity. Theory predicts positive effects of microbial diversity that result from functional niche complementarity, but the few existing experiments provide...
thumbnail
The data contain yearly modeled estimates of Pacific salmon escapement (in annual metric tons of wet mass) from 1976 to 2015 across four regions of western North America. A second data file contains modeled estimates of contaminant or nutrient concentrations in Pacific Salmon. The modeled estimates were derived from Bayesian generalized linear models (contaminant or nutrient concentrations) or from Bayesian generalized additive models (Salmon Escapement).
thumbnail
This U.S. Geological Survey data release provides a comprehensive dataset of water-quality data and sampling-site characteristics collected in 1978–2018 during a study of the effects of land disposal of treated wastewater on groundwater quality in an unconsolidated sand and gravel aquifer on Cape Cod, Massachusetts. Treated sewage-derived wastewater was discharged to rapid-infiltration beds at Joint Base Cape Cod for nearly 60 years before the disposal was moved to a different location in December 1995. The discharge formed a plume of contaminated groundwater that partly discharges to a glacial kettle lake about 1,600 feet from the beds and extends about 4.5 miles toward coastal saltwater bodies at Vineyard Sound....
thumbnail
This U.S. Geological Survey (USGS) data release provides a comprehensive dataset of water-quality results, physical-parameter measurements, hydrologic measurements, and site information collected to study the nature and extent of water quality along groundwater flow paths adjacent to glacial-kettle lakes on Cape Cod, Massachusetts. Water-quality samples were collected in 2003, 2005, and 2012 through 2018 in and near seven kettle lakes located on western Cape Cod, with most of the data collected in 2015-2017 from Ashumet Pond, which is located in the towns of Falmouth and Mashpee. Data were also collected at other lakes to compare the lake-specific influences of geochemistry and hydrology on the downgradient groundwater...
We explore empirical and theoretical evidence for the functional significance of plant-litter diversity and the extraordinary high diversity of decomposer organisms in the process of litter decomposition and the consequences for biogeochemical cycles. Potential mechanisms for the frequently observed litter-diversity effects on mass loss and nitrogen dynamics include fungi-driven nutrient transfer among litter species, inhibition or stimulation of microorganisms by specific litter compounds, and positive feedback of soil fauna due to greater habitat and food diversity. Theory predicts positive effects of microbial diversity that result from functional niche complementarity, but the few existing experiments provide...
Microbial activity in semiarid and arid environments is closely related to the timing, intensity, and amount of precipitation. The characteristics of the soil surface, especially the influence of biological soil crusts, can determine the amount, location, and timing of water infiltration into desert soils, which, in turn, determines the type and size of microbial response. Nutrients resulting from this pulse then create a positive feedback as increases in microbial and plant biomass enhance future resource capture or, alternatively, may be lost to the atmosphere, deeper soils, or downslope patches. When rainfall intensity overwhelms the water infiltration capacity of the plant interspace or the plant patch, overland...
thumbnail
The detrimental effects of excess nutrients and sediment entering the Chesapeake Bay estuary from its watersheds have necessitated regulatory actions. Federally-mandated reductions are apportioned to bay jurisdictions based on the U.S. Environmental Protection Agency's Chesapeake Bay Time-Variable Watershed Model (CBPM). The Chesapeake Assessment Scenario Tool (CAST version CAST-19; cast.chesapeakebay.net; Chesapeake Bay Program, 2020) is a simplified, on-line version of the Phase 6 CBPM that simulates watershed nutrients delivery to the estuary using the original model's annual land-surface nutrient source and removal inputs and time-averaged climatological forecasting. Because it runs much faster than the CBPM,...
Plant roots and soil microorganisms contain significant quantities of low molecular weight (MW) phosphorylated nucleosides and sugars. Consequently, upon death these can represent a significant input of organic-P to the soil. Some of these organic-P substrates must first be dephosphorylated by phosphatases before being assimilated by the soil microbial community while others can be taken up directly from soil solution. To determine whether sorption or phosphatase activity was limiting the bioavailability of low MW organic-P in soil we compared the microbial uptake and C mineralization of a range of 14C-labeled organic-P substrates [glucose-6-phosphate, adenosine monophosphate (AMP), adenosine diphosphate (ADP) and...
Widespread loss of sagebrush (Artemisia tridentata) in much of the western US represents a major shift in the dominant species type and may trigger changes in ecosystem characteristics such as the distribution of nutrients. We examined total nitrogen (N) and carbon (C) content of soils directly below and away from Wyoming big sagebrush (A. tridentata ssp. tridentata) canopies in undisturbed areas, where shrubs had been removed for six years, and in areas that have received annual additions of nitrogen, to improve our understanding of the effects of shrub canopies and perturbations on nutrient distribution. Soils below shrub canopies had more C and N than soils in open interspaces; resource islands were still present...
thumbnail
Data were collected to determine the abundance of nitrogen-fixing microorganisms in Cladophora algae growing on rocks, breakwall structures, or submerged dreissenid mussel beds around southern Lake Michigan. Cladophora samples (N=33) were collected between June and September 2015 from three urban areas: (a) Jeorse Park, East Chicago, Indiana, (b) Calumet Beach, Chicago, Illinois, and (c) North Beach, Racine, Wisconsin, and a National Park site, Portage Lakefront, Indiana Dunes National Park, Indiana. Corresponding lake water samples (N=33) were collected approximately 15-20 feet away from submerged algal mats. Genomic DNA was extracted from water and processed algal samples. The abundance of nitrogen-fixing microorganisms...
thumbnail
In 2014, the USGS Lake Erie Biological Station participated in the Coordinated Science and Monitoring Initiative (CMSI) program, a program founded by the U.S. Environmental Protection Agency (EPA) and Environment Canada in the 1990s as a means to focus collaborative research attention on one of the five Great Lakes each year (on a rotating schedule) as a means to increase scientific knowledge for Great Lakes restoration. The Lake Erie survey examined the food web across a nearshore to offshore gradient, matching the sampling design the preceding USGS studies of the other four Great Lakes (2010-2013). We sampled all trophic levels in all three lake basins across multiple seasons in order to determine nutrient availability...
Limited data exist on the affect of downy brome invasion on biogeochemical cycling. Biogeochemical cycling was quantified in a winterfat community in northeastern, CA that was separated into three invasion classes: noninvaded (NI), invaded for 3 yr (I3), and 10 yr (I10) by downy brome. On each plot, all aboveground vegetation was harvested and separated by species, dried, weighed, and tissue nutrients quantified. In addition, soil samples were collected from 0- to 30-, 30- to 60-, and 60- to 100-cm depths and various nutrient pools quantified. Aboveground biomass g/m2 was significantly greater, with downy brome averaging over 90% of the plant mass on the I10 plots (280 g) compared to the NI plots (148 g). In comparison...


map background search result map search result map Lake Erie Collaborative Science and Monitoring Initiative 2014 Chemical Data From 40 Years of Monitoring a Treated-Wastewater Groundwater Plume in a Sand and Gravel Aquifer, Cape Cod, Massachusetts, 1978-2018 Geochemical Data Supporting Analysis of Fate and Transport of Nitrogen in the Nearshore Groundwater and Subterranean Estuary near East Falmouth, Massachusetts, 2015-2016 Erosion and Rehabilitation Data, Bandelier National Monument, New Mexico, USA Water-Quality Data in and near Groundwater Flow-Through Kettle-Hole Lakes, Western Cape Cod, Massachusetts, 2003 - 2018 Quantification of nitrogen-fixing microorganisms (targeting nifH gene) in Cladophora algae by quantitative polymerase chain reaction (qPCR) CAST Data Input Disaggregation from County and Land-River Segment Scale to National Hydrography Dataset Plus, Version 1.1 Carbon and Nitrogen Content of Organic Soils in Lake-Margin Wetlands of the Yukon Flats National Wildlife Refuge Soil Properties of Lake-Margin Wetlands of the Yukon Flats National Wildlife Refuge Phosphorus, nitrogen, carbon, calcium, pH, and dissolved oxygen data from incubations of Colorado River water and sediment and associated ambient river water measurements Modeled Pacific salmon escapement biomass and nutrient and contaminant concentrations across western North America, 1976-2015 Geochemical Data Supporting Analysis of Fate and Transport of Nitrogen in the Nearshore Groundwater and Subterranean Estuary near East Falmouth, Massachusetts, 2015-2016 Water-Quality Data in and near Groundwater Flow-Through Kettle-Hole Lakes, Western Cape Cod, Massachusetts, 2003 - 2018 Chemical Data From 40 Years of Monitoring a Treated-Wastewater Groundwater Plume in a Sand and Gravel Aquifer, Cape Cod, Massachusetts, 1978-2018 Quantification of nitrogen-fixing microorganisms (targeting nifH gene) in Cladophora algae by quantitative polymerase chain reaction (qPCR) Phosphorus, nitrogen, carbon, calcium, pH, and dissolved oxygen data from incubations of Colorado River water and sediment and associated ambient river water measurements Lake Erie Collaborative Science and Monitoring Initiative 2014 Carbon and Nitrogen Content of Organic Soils in Lake-Margin Wetlands of the Yukon Flats National Wildlife Refuge Soil Properties of Lake-Margin Wetlands of the Yukon Flats National Wildlife Refuge CAST Data Input Disaggregation from County and Land-River Segment Scale to National Hydrography Dataset Plus, Version 1.1 Modeled Pacific salmon escapement biomass and nutrient and contaminant concentrations across western North America, 1976-2015