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Full-Text Articles in Life Sciences

Cover Crop Biomass Production And Water Use In The Central Great Plains, David C. Nielsen, Drew J. Lyon, Gary W. Hergert, Robert K. Higgins, Johnathon D. Holman Aug 2015

Cover Crop Biomass Production And Water Use In The Central Great Plains, David C. Nielsen, Drew J. Lyon, Gary W. Hergert, Robert K. Higgins, Johnathon D. Holman

David C. Nielsen

The water-limited environment of the semiarid Central Great Plains may not produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater water use efficiency than single-species plantings. This study was conducted to determine differences in cover crop biomass production, water use efficiency, and residue cover between a mixture and single-species plantings. The study was conducted at Akron, CO, and Sidney, NE, during the 2012 and 2013 growing seasons under both rainfed and irrigated conditions. Water use, biomass, and …


Microbe-Mineral Relationships And Biogenic Mineral Transformations In Actively Venting Deep-Sea Hydrothermal Sulfide Chimneys, Tzihsuan J. Lin May 2014

Microbe-Mineral Relationships And Biogenic Mineral Transformations In Actively Venting Deep-Sea Hydrothermal Sulfide Chimneys, Tzihsuan J. Lin

TZIHSUAN J LIN

This dissertation uses a combination of microbiology, mineralogy, and geochemistry to understand dissimilatory iron reduction in hyperthermophilic archaea and the role and potential impact of these and other vent microorganisms within active deep-sea hydrothermal vent chimneys. The central objective of the dissertation is to determine if mineral composition and chimney type are among the primary determinants of microbial community composition and hyperthermophilic, dissimilatory iron reducer growth, in addition to other environmental factors such as nutrient availability, temperature, pH, and chlorinity. This is done using samples and organisms collected from the Endeavour Segment of the Juan de Fuca Ridge in the …


Soil Penetrometer, David A. Bainbridge Jan 2014

Soil Penetrometer, David A. Bainbridge

David A Bainbridge

A simple easy to build impact soil penetrometer can provide very useful information on soil strength. This can be very important for restoration planning and management of soils in agriculture and forestry.


Soil Solarization, David A. Bainbridge Jan 2014

Soil Solarization, David A. Bainbridge

David A Bainbridge

Soil solarization makes use of the energy of the sun to heat soil and kill weeds and pathogens. Single, double, or bubblepack plastic and be used to increase soil temperature. Multiple growth benefits are often realized.


Changing Climate And The Altitudinal Range Of Avian Malaria In The Hawaiian Islands – An Ongoing Conservation Crisis On The Island Of Kaua`I, Carter T. Atkonson, Ruth B. Utzurrum, Dennis A. Lapointe, Richard J. Camp, Lisa H. Crampton, Jeffrey T. Foster, Thomas W. Giambelluca Jan 2014

Changing Climate And The Altitudinal Range Of Avian Malaria In The Hawaiian Islands – An Ongoing Conservation Crisis On The Island Of Kaua`I, Carter T. Atkonson, Ruth B. Utzurrum, Dennis A. Lapointe, Richard J. Camp, Lisa H. Crampton, Jeffrey T. Foster, Thomas W. Giambelluca

Richard J. Camp

Transmission of avian malaria in the Hawaiian Islands varies across altitudinal gradients and is greatest at elevations below 1500 m where both temperature and moisture are favorable for the sole mosquito vector, Culex quinquefasciatus, and extrinsic sporogonic development of the parasite, Plasmodium relictum. Potential consequences of global warming on this system have been recognized for over a decade with concerns that increases in mean temperatures could lead to expansion of malaria into habitats where cool temperatures currently limit transmission to highly susceptible endemic forest birds. Recent declines in two endangered species on the island of Kaua’i, the ‘Akikiki (Oreomystis bairdi) …


The Contribution Of Fe (Iii) And Humic Acid Reduction To Ecosystem Respiration In Drained Thaw Lake Basins Of The Arctic Coastal Plain, David A. Lipson, Ted K. Raab, Dominic Goria, Jaime Zlamal May 2013

The Contribution Of Fe (Iii) And Humic Acid Reduction To Ecosystem Respiration In Drained Thaw Lake Basins Of The Arctic Coastal Plain, David A. Lipson, Ted K. Raab, Dominic Goria, Jaime Zlamal

Ted K. Raab

Previous research showed that anaerobic respiration using iron (Fe) oxides as terminal electron acceptor contributed substantially to ecosystem respiration (ER) in a drained thaw lake basin (DTLB) on the Arctic coastal plain. As DTLB age, the surface organic layer thickens, progressively burying the Fe-rich mineral layers. We therefore hypothesized that Fe (III) availability and Fe reduction would decline with basin age. We studied four DTLB across an age gradient, comparing seasonal changes in the oxidation state of dissolved and extractable Fe pools and the estimated contribution of Fe reduction to ER. The organic layer thickness did not strictly increase with …


Classification Of The Alterations Of Beaver Dams To Headwater Streams In Northeastern Connecticut, U.S.A., Denise Burchsted, Melinda D. Daniels Jan 2013

Classification Of The Alterations Of Beaver Dams To Headwater Streams In Northeastern Connecticut, U.S.A., Denise Burchsted, Melinda D. Daniels

Denise Burchsted

Of the many types of barriers to water flow, beaver dams are among the smallest, typically lasting less than a decade and rarely exceeding 1.5 m in height. They are also among the most frequent and common obstructions in rivers, with a density often exceeding ten dams per km, a frequency of construction within a given network on a time scale of years, and a historic extent covering most of North America. Past quantification of the geomorphologic impact of beaver dams has primarily been limited to local impacts within individual impoundments and is of limited geographic scope. To assess the …


An Assessment Of The Effects Of Desertification In Yobe State, Nigeria, Jibril Musa Phd Dec 2012

An Assessment Of The Effects Of Desertification In Yobe State, Nigeria, Jibril Musa Phd

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Desertification is one of the most serious environmental and socio-economic problems of our time. Desertification describes circumstances of land degradation in arid, semi-arid and dry sub-humid regions resulting from the climatic variation and human activities. The fundamental goal of this thesis was to assess the effects of desertification in Yobe State, Nigeria. The present threat of desertification in the sahel has reached an alarming stage where crops cultivation and animal rearing/grazing are no more productive, soil has lost its nutrient/fertility, various infrastructure had given way because of windstorm from the neighbouring Niger Republic and sand dunes had taken over. The …


Using Remote Sensing Data To Improve Rice Production In Kutigi, Niger State, Nigeria, Jibril Musa Phd, M B. Yunusa Dec 2012

Using Remote Sensing Data To Improve Rice Production In Kutigi, Niger State, Nigeria, Jibril Musa Phd, M B. Yunusa

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This research work looked in the used of Remote Sensing to improve Agricultural production in Kutigi, Niger State. The aim of the study is to use remote sensing to improve rice farming activities in Kutigi, Niger State. It is very important to identify such methods to improve Agricultural production because experts are always interested in new researches and findings to better the standard of living in any environment. In view of this, Remotely-sensed data could be used or employed to elevate most of these agricultural problems in Kutigi through the following objectives: Using Landsat imagery to assess the present landuse …


Mapping The Surface Characteristics Of The Mojave With Remote Sensing For Terrestrial Habitat Modeling, Scott A. Nowicki Dec 2012

Mapping The Surface Characteristics Of The Mojave With Remote Sensing For Terrestrial Habitat Modeling, Scott A. Nowicki

Scott A Nowicki

High-resolution ecological and climate modeling requires quantification of surface characteristics such as rock abundance, soil induration and surface roughness at fine-scale, since these features can affect the micro and macro habitat of a given area and ultimately determine the assemblage of plant and animal species that may occur there. Our objective is to develop quantitative data layers of thermophysical properties of the entire Mojave Desert Ecoregion for applications to habitat modeling being conducted by the USGS Western Ecological Research Center. These research efforts are focused on developing habitat models and a better physical understanding of the Mojave Desert, which have …


Variations In Climatic Parameters And Food Crop Yields: Implications On Food Security In Benue State, Nigeria., Emmanuel Adamgbe, Fanan Ujoh Oct 2012

Variations In Climatic Parameters And Food Crop Yields: Implications On Food Security In Benue State, Nigeria., Emmanuel Adamgbe, Fanan Ujoh

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Agricultural production in Nigeria like in other developing countries is highly vulnerable to variations in climatic parameters which may have inverse or direct effect on the performance of food crops. This paper examines the patterns and trends of the variations in the climatic parameters and the implications of such variations on efficient yield rates of some food crops in Benue State using data on climatic variables (rainfall, temperature, sunshine) and the yield of some crops per hectare for 25 years (1986-2010). Data on the climatic variables were collected from the Nigerian Meteorological Agency, AirForce Base, Makurdi while the data on …


Evidence That Glucose Is The Major Transferred Metabolite In Dinoflagellate–Cnidarian Symbiosis, Matthew S. Burriesci, Ted K. Raab, John R. Pringle Oct 2012

Evidence That Glucose Is The Major Transferred Metabolite In Dinoflagellate–Cnidarian Symbiosis, Matthew S. Burriesci, Ted K. Raab, John R. Pringle

Ted K. Raab

Reef-building corals and many other cnidarians are symbiotic with dinoflagellates of the genus Symbiodinium. It has long been known that the endosymbiotic algae transfer much of their photosynthetically fixed carbon to the host and that this can provide much of the hostʼs total energy. However, it has remained unclear which metabolite(s) are directly translocated from the algae into the host tissue. We reexamined this question in the small sea anemone Aiptasia using labeling of intact animals in the light with 13C-bicarbonate, rapid homogenization and separation of animal and algal fractions, and analysis of metabolite labeling by gas chromatography-mass spectrometry. We …


Environmental Impacts Of Stover Removal In The Corn Belt, Alicia English, Wallace E. Tyner, Juan Sesmero, Phillip Owens, David J. Muth Jr. Aug 2012

Environmental Impacts Of Stover Removal In The Corn Belt, Alicia English, Wallace E. Tyner, Juan Sesmero, Phillip Owens, David J. Muth Jr.

David J. Muth

When considering the market for biomass from corn stover resources erosion and soil quality issues are important to consider. Removal of stover can be beneficial in some areas, especially when coordinated with other conservation practices, such as vegetative barrier strips and cover crops. However, benefits are highly dependent on several factors, namely if farmers see costs and benefits associated with erosion and the tradeoffs with the removal of biomass. This paper uses results from an integrated RUSLE2/WEPS model to incorporate six different regime choices, covering management, harvest and conservation, into a simple profit maximization model to show these tradeoffs.


Dynamics Of Land Use/Land Cover Changes And Its Implication On Food Security In Anyigba, North Central, Nigeria, Tokula E. Arome, Sunday P. Ejaro (Phd) May 2012

Dynamics Of Land Use/Land Cover Changes And Its Implication On Food Security In Anyigba, North Central, Nigeria, Tokula E. Arome, Sunday P. Ejaro (Phd)

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This study assessed land use/land cover changes and its effect on Agricultural land in Anyigba. The objectives were to identify and delineate different land use / land cover categories, assess the rate of change that occurred and examine the impact of land use/land cover change on food security using satellite remote sensing data collected at three different years (1987 Land sat TM, 2001 Land Sat TM and 2011 Land Sat ETM). The study utilized GIS software such as Idrisi Andes academic and ArcGIS 9.3. The study area covers approximately 31.8km2, and four major land use/cover classes were utilized (built up, …


Socio-Economic Effects Of Demolishing Squatter Settlements And Illegal Structures In Abuja Metropolis, Federal Capital Territory, Nigeria, Ishaku Iy Mallo Phd, Victor G. Obasanya Jan 2012

Socio-Economic Effects Of Demolishing Squatter Settlements And Illegal Structures In Abuja Metropolis, Federal Capital Territory, Nigeria, Ishaku Iy Mallo Phd, Victor G. Obasanya

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Abuja the Federal Capital Territory and study area is located between latitudes 8o25’ and 9o25’ North of the Equator and longitudes 6o45’ and 7o45’ East of the Greenwich Meridian. The study was carried out in Abuja Phase 1, and it is aimed at highlighting various socioeconomic effects of demolition of illegal structures and informal or squatter settlements on the people within the study area. Data was collected through reconnaissance survey, personal interviews with respondents, and a well laid out questionnaire. The results indicate that the demolition exercise embarked upon by the authorities in the Federal Capital Territory was a response …


Rainfall Variability And Crop Zones Classification For The Federal Capital Territory, Nigeria, Shaibu M. Hassan Phd Jan 2012

Rainfall Variability And Crop Zones Classification For The Federal Capital Territory, Nigeria, Shaibu M. Hassan Phd

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This study aims at analyzing agro-climatological parameters and establishing a link between some selected agro-climatological indices and sustainability of agricultural production in the Federal Capital Territory (FCT). Two sets of data, climatic and crop yield data were collected and subjected to various agro-climatological analyses. Agro-climatological analyses include the derivation of Onset, Cessation and Length of Rainy Season (LRS), Seasonality Index, Drought Index and Precipitation Periodicity Index. The statistical analyses include monthly and annual means, deviation from the mean, trend line. The result of moisture index in line with crops optimum moisture requirement was used to classify the Territory into agro-climatic …


Water Table Height And Microtopography Control Biogeochemical Cycling In An Arctic Coastal Tundra Ecosystem, David A. Lipson, Donatella Zona, Ted K. Raab, Francis Bozzolo, Marguerite Mauritz, Walter C. Oechel Jan 2012

Water Table Height And Microtopography Control Biogeochemical Cycling In An Arctic Coastal Tundra Ecosystem, David A. Lipson, Donatella Zona, Ted K. Raab, Francis Bozzolo, Marguerite Mauritz, Walter C. Oechel

Ted K. Raab

Drained thaw lake basins (DTLB’s) are the dominant land form of the Arctic Coastal Plain in northern Alaska. The presence of continuous permafrost prevents drainage and so water tables generally remain close to the soil surface, creating saturated, suboxic soil conditions. However, ice wedge polygons produce microtopographic variation in these landscapes, with raised areas such as polygon rims creating more oxic microenvironments. The peat soils in this ecosystem store large amounts of organic carbon which is vulnerable to loss as arctic regions continue to rapidly warm, and so there is great motivation to understand the controls over microbial activity in …


Landscape Management For Sustainable Supplies Of Bioenergy Feedstock And Enhanced Soil Quality, Douglas L. Karlen, David J. Muth Jr. Jan 2012

Landscape Management For Sustainable Supplies Of Bioenergy Feedstock And Enhanced Soil Quality, Douglas L. Karlen, David J. Muth Jr.

David J. Muth

Agriculture can simultaneously address global food, feed, fi ber, and energy challenges provided our soil, water, and air resources are not compromised in doing so. As we embark on the 19th Triennial Conference of the International Soil and Tillage Research Organization (ISTRO), I am pleased to proclaim that our members are well poised to lead these endeavors because of our comprehensive understanding of soil, water, agricultural and bio-systems engineering processes. The concept of landscape management, as an approach for integrating multiple bioenergy feedstock sources, including biomass residuals, into current crop production systems, is used as the focal point to show …


Assessment Of Organic And Inorganic Phosphorus In Soils Derived From Cretaceous Sediments And Basement Complex Soils Of Guinea Savannah Of Kogi State, North Central Nigeria, Sunday I. Amhakhian, H H. Isitekhale, Charles I. Oyewole Aug 2011

Assessment Of Organic And Inorganic Phosphorus In Soils Derived From Cretaceous Sediments And Basement Complex Soils Of Guinea Savannah Of Kogi State, North Central Nigeria, Sunday I. Amhakhian, H H. Isitekhale, Charles I. Oyewole

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

A pot experiment was carried out using 20 surface soils (0-15cm depth) in 2008 to assess soil organic phosphorus and some fraction of inorganic phosphorus in other to know their availability in the soils of the studied area and also work have not been done in this areas in respect to organic and in-organic phosphorus. The experiment was conducted using 20 soils 10 from each geological formation (Cretaceous sediments and Basement complex soils), respectively. The mean organic phosphorus of 63.51 mgkg 1 soil was obtained for Cretaceous sediment soils and 158.54 mgkg 1 soil for the basement complex soils respectively. …


Development Of Functional Indices Of Facility Occurrence Towards The Distribution Of Social Services In Lagos Island Nigeria., Augustus O. Atubi Aug 2011

Development Of Functional Indices Of Facility Occurrence Towards The Distribution Of Social Services In Lagos Island Nigeria., Augustus O. Atubi

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Proper coordination of transport and public facilities provision is vital to any balanced regional development strategy. The central aim of this study, therefore, is to find out what the relationship is between access to the transport network and the provision of functional indices of facility occurrence towards the distribution of social services in Lagos Island, Nigeria. In particular it seeks to find out areas that have below or above average level of facility occurrences relative to the level of accessibility. However, a pair wise correlation matrix of the eleven (11) variables employed in the index construction was carried out. The …


Urban Climate And Challenges Of Tropical Cities, B E. Omogbai Jul 2011

Urban Climate And Challenges Of Tropical Cities, B E. Omogbai

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This study examines the nature of urban climate, features and the challenges on the developing tropical cities in the 21st century. It argues that the use of principles of urban climate would help in providing comfortable living conditions and problem immune working environments for the inhabitants of tropical cities. The findings reveal that owing to poor environmental planning, inadequate geotechnical landscape surveys prior to the development of urban infrastructures, and non-adherence to the principles of urban climate, challenges of landscape degradation, excessive flooding of the built infrastructures, heat-island effects, and collapse of buildings have emerged. Suggested measures to avert these …


Detecting Changes In Landuse/Cover Of Umuahia, South-Eastern Nigeria Using Remote Sensing And Gis Techniques, Fanan Ujoh, Olarewaju Oluseyi Ifatimehin, Adams Ndalai Baba Jul 2011

Detecting Changes In Landuse/Cover Of Umuahia, South-Eastern Nigeria Using Remote Sensing And Gis Techniques, Fanan Ujoh, Olarewaju Oluseyi Ifatimehin, Adams Ndalai Baba

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Since 1991 when it became the capital city of Abia State, Umuahia has undergone tremendous transformation in its land use and land cover due to rapid urbanization. The main materials employed for this study are a land use map (1991) and Landsat ETM+satellite image (2007) of the study area. These, combined with field survey/checks, were brought into a GIS environment using ILWIS 3.2 Academic image classification software to map the land use/land cover and to estimate the rate of urban expansion and loss of rural land at the peri-urban fringes of Umuahia between 1991 and 2007. The study revealed significant …


Gender Participation In The Management Of Tricycle Transport For Youth Empowerment And Sustainable Development In Kano State, Nigeria, Nuratu Muhammed Jun 2011

Gender Participation In The Management Of Tricycle Transport For Youth Empowerment And Sustainable Development In Kano State, Nigeria, Nuratu Muhammed

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

The research examined gender participation in the management of tricycle for youth empowerment and sustainable development in Kano state, Nigeria. Stratified random sampling technique was used to select samples of drivers(150), passengers (150) and owners/managers the female tricycle owners fell under this category and they numbered(65).All together a total of 365 samples were selected for the study. Data obtained from the primary data was analyzed using simple statistical techniques and chi square test to ascertain whether there was any significant differences in some of the variables tested. The results of the analysis revealed that the main difference was found in …


Science Boot Camp For Librarians: Cpd On A Shoestring, Maxine G. Schmidt, Rebecca Reznik-Zellen May 2011

Science Boot Camp For Librarians: Cpd On A Shoestring, Maxine G. Schmidt, Rebecca Reznik-Zellen

Maxine G Schmidt

Science Boot Camp for Librarians was envisioned as a casual but intensive immersion event into selected scientific subjects that employ networked computing capabilities for research and collaboration. The goal of the event is to provide librarians with networking opportunities, but more importantly, to give them some of the context and ocabulary of a discipline to enable them to better engage faculty and research scientists with regard to escience. A half-day is devoted to each of three topics chosen for that year’s camp. A local faculty member provides an overview of the research area, and a second describes a single project …


Environmental Problems Of Industrialization And Sustainable Development In Nigeria - A Review, Adejoh Iyaji Feb 2011

Environmental Problems Of Industrialization And Sustainable Development In Nigeria - A Review, Adejoh Iyaji

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

The main objective of this paper is to examine the impact of the quest for industrialization on the environment in Nigeria; others include, the identification of the objectives of sustainable development as well as making recommendations that will lead to the much needed sustainable environment both for the present generation and generations yet unborn. The researcher relied principally on secondary sources of data for this paper which is theoretical in approach. Findings revealed the emergence of a host of environmental problems such as air pollution, deforestation, desertification, solid and hazardous waste problems in the wake of the quest for industrialization. …


Creating A Soil Data Base In A Reconnaissance Soil Fertility Ssstudy Of An Encroached Forest Reserve In Northern Nigeria For A Reforestation Programme, F O. Adekayode, Dr. Dipo Theophilus Akomolafe Mbcs, Mncs, Mcpn, Jan 2011

Creating A Soil Data Base In A Reconnaissance Soil Fertility Ssstudy Of An Encroached Forest Reserve In Northern Nigeria For A Reforestation Programme, F O. Adekayode, Dr. Dipo Theophilus Akomolafe Mbcs, Mncs, Mcpn,

Dr. Dipo Theophilus Akomolafe MBCS, MNCS, MCPN,

The reconnaissance soil fertility study of 10,000 ha partly encroached forest reserve located between latitude 11°47’N and 11°56’N and longitude 4°22’E and 4°32’E in Northern Nigeria was conducted in 2009 to generate a soil fertility data base of the reserve. The tracking of the forest reserve boundary was done using a Garmin 72 model global positioning system (GPS) receiver. The geographic coordinates were input into the computer to generate a digital map of the forest reserve. The entire forest reserve was divided into grids to guide in the location for soil sampling using the GPS/Geographic Information System (GIS) geospatial technique. …


Adaptive Responses To Flooding Incidents In Ilorin, Kwara State, Nigeria, Habiba I. Jimoh, Kayode A. Iroye Jan 2011

Adaptive Responses To Flooding Incidents In Ilorin, Kwara State, Nigeria, Habiba I. Jimoh, Kayode A. Iroye

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Incidents of floods which are mainly caused by changes in landuse is fast becoming a city life experience in Ilorin as in most urban centres in Nigeria causing untold hardships and sometimes loss of lives. This extreme hydro-meteorological event is also being exacerbated by climate change which thus calls for adaptive response by residents towards reducing its risks, hence this study. Data used were generated from direct field measurements and questionnaire administration. Descriptive statistics and cross tabulations were used in analyzing the data. Results obtained indicate that most respondents use a wide range of non-structural adaptive response to flood. The …


An Assessment Of Socio-Economic Impact Of Waste Scavenging As A Means Of Poverty Alleviation In Gwagwalada, Abuja., John Yakubu Magaji, Samuel Panse Dakyes Jan 2011

An Assessment Of Socio-Economic Impact Of Waste Scavenging As A Means Of Poverty Alleviation In Gwagwalada, Abuja., John Yakubu Magaji, Samuel Panse Dakyes

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Waste scavengers are usually perceived as being among the poor, and scavenging is considered a marginal activity. They tend to have low incomes, but can obtained decent earning when they are not exploited by middlemen. This study was conducted in Gwagwalada town with the aim of assessing the socio-economic impact of scavenging on the people. A structured questionnaire was constructed to capture the demographic characteristics of the scavengers, their experiences, types of items scavenged, the economic gains and the challenges being faced. The target pollution is waste scavengers and a random sampling technique was adopted in selecting the respondents for …


Reduction Of Iron (Iii) And Humic Substances Plays A Major Role In Anaerobic Respiration In An Arctic Peat Soil, David A. Lipson, Mony Jha, Ted K. Raab, Walter C. Oechel Dec 2010

Reduction Of Iron (Iii) And Humic Substances Plays A Major Role In Anaerobic Respiration In An Arctic Peat Soil, David A. Lipson, Mony Jha, Ted K. Raab, Walter C. Oechel

Ted K. Raab

Arctic peat soils contain vast reserves of organic C and are largely anaerobic. However, anaerobic respiration, particularly the role of Fe(III) and humic substances as electron acceptors, is not well understood in such ecosystems. We investigated these processes in a drained thaw lake basin on the Arctic coastal plain near Barrow, Alaska. We measured concentrations of soluble Fe and other potential electron acceptors, described the microbial community, and performed experiments in the laboratory and field to measure net rates of Fe(III) reduction and the relationship of this process to C cycling. In most areas within the basin, aerobic conditions existed …


Background Fluorescence In Groundwater From A Tropical Karst Island Aquifer, Michelle Hoffman Sep 2010

Background Fluorescence In Groundwater From A Tropical Karst Island Aquifer, Michelle Hoffman

Michelle Hoffman

Background levels of four fluorescent compounds were monitored biweekly at thirteen sampling sites on Guam, consisting of subtidal and intertidal springs, dissolution fractures, and internal upland contact spring discharge, over a 13-month period from 2006 to 2007. Samples were compared to local precipitation and to seawater samples from four nearby reef flats. The data revealed that the concentrations of optical brighteners were consistently two orders of magnitude greater than either sodium fluorescein or rhodamine WT, while Eosine Y was rarely detected. Background levels in seawater, by comparison, accounted for 25% or more of the fluorescent compounds detected at the thirteen …