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Articles 10831 - 10860 of 14056

Full-Text Articles in Oceanography and Atmospheric Sciences and Meteorology

Spatial And Temporal Recruitment Patterns Of Juvenile Grunts (Haemulon Spp.) In South Florida, L. K. B. Jordan, David S. Gilliam, Robin L. Sherman, Paul T. Arena, Fleur M. Harttung, Robert M. Baron, Richard E. Spieler Jan 2004

Spatial And Temporal Recruitment Patterns Of Juvenile Grunts (Haemulon Spp.) In South Florida, L. K. B. Jordan, David S. Gilliam, Robin L. Sherman, Paul T. Arena, Fleur M. Harttung, Robert M. Baron, Richard E. Spieler

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

Grunts (Haemulidae) are important fisheries species and represent a major component of reef fish communities in the Greater Caribbean region. To date, little is known about their recruitment pattems. Data from more than 2,000 visual fish counts from multiple natural and artificial reef studies in Broward County, Florida, over a seven-year period, were examined to identify both spatial and temporal trends in recruitment of juvenile (i.e., < 5cm TL) grunts of the genus Haemulon. In general, data from these studies indicate that juvenile Haemulon spp. recruitment increases in the spring and peaks in the early summer months (i.e., June and July). Data from natural reef surveys revealed a predominantly nearshore preference for recruitment in water depths less than 8 m. However, on artificial reefs, recruitment commoniy occurred at 20 m depths. The biotic and abiotic factors determining the settlement of grunts are not clear and will be examined in future studies.


Presence Of Juvenile Blackfin Snapper, Lutjanus Buccanella, And Snowy Grouper, Epinephelus Niveatus, On Shallow-Water Artificial Reefs, Paul T. Arena, Patrick Quinn, Lance K. B. Jordan, Robin L. Sherman, Fleur M. Harttung, Richard E. Spieler Jan 2004

Presence Of Juvenile Blackfin Snapper, Lutjanus Buccanella, And Snowy Grouper, Epinephelus Niveatus, On Shallow-Water Artificial Reefs, Paul T. Arena, Patrick Quinn, Lance K. B. Jordan, Robin L. Sherman, Fleur M. Harttung, Richard E. Spieler

Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures

The inshore environment of Broward County, Florida consists of three reef tracts, each separated by sand substrate, running parallel to the coastline in sequentially deeper water. A wide variety of artificial reef designs have been deployed in Broward County, many lying in sand flats between the reeftracts. From 1995 through 2002, over 1,100 visual fish censuses (predominantly point-counts) were completed on the three natural reeftracts in water depths from 3 m to 30 m and over 1,100 censuses were done on artificial reefs at depths of 7 m to 23 m. Curiously, the juvenile stages of two deeper-water species of …


An Association Of Benthic Foraminifera And Gypsum In Holocene Sediments Of Estuarine Chesapeake Bay, Usa, John Cann, Thomas Cronin Jan 2004

An Association Of Benthic Foraminifera And Gypsum In Holocene Sediments Of Estuarine Chesapeake Bay, Usa, John Cann, Thomas Cronin

United States Geological Survey: Staff Publications

Two cores of Holocene sediments recovered from the Cape Charles Channel of Chesapeake Bay yielded radiocarbon ages of about 6.8 to 5.8 ka for the lower intervals. Fossil foraminifera preserved in these lower sediments are dominated by species of Elphidium, which make up about 90% of the assemblage throughout, and probably signify deposition in hypersaline waters. Buccella frigida and Ammonia beccarii are the only other species commonly present. Hypersalinity of bottom waters seems to have been maintained by water-density stratification in a basin-like section of the channel. In core PTXT -4-P-I transition to modem Chesapeake conditions, in which numbers …


Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr. Jan 2004

Grassland Vegetation And Bird Communities In The Southern Great Plains Of North America, Robert N. Chapman, David M. Engle, Ronald E. Masters, David M. Leslie Jr.

United States Geological Survey: Staff Publications

Structure and composition of vegetation and abundance of breeding birds in grasslands seeded to Old World bluestem (Bothriochloa ischmaeum) were compared to native mixed prairie in the southern Great Plains of North America. Abundance of birds was determined using fixed-radius point counts. Detrended correspondence analysis was used to compare plant community composition and canonical correspondence analysis was used to examine the relationships between plant species composition and vegetation structure with the bird community. Plant species composition differed distinctly between seeded grassland and native mixed prairie, but the differences were not reflected in habitat structure, bird community composition, or …


Recent Advances In Drought Monitoring, Mark D. Svoboda, Michael J. Hayes, Donald A. Wilhite, Tsegaye Tadesse Jan 2004

Recent Advances In Drought Monitoring, Mark D. Svoboda, Michael J. Hayes, Donald A. Wilhite, Tsegaye Tadesse

National Drought Mitigation Center: Faculty Publications

Recent widespread, severe, and long-lasting droughts across North America have heightened awareness of and interest in how to better monitor drought and its impacts. Since its inception in 1999, the National Drought Mitigation Center (NDMC), United States Department of Agriculture (USDA) and NOAA’s Climate Prediction Center (CPC) and National Climatic Data Center (NCDC) have partnered to produce the weekly U.S. Drought Monitor (http://droug ht.unl.edu/m onitor/), a comprehensive drought assessment product based on a simple 5- category severity classification. On the heels of its widespread acceptance and usage, the NCDC, CPC, USDA, NDMC and scientists from Canada and Mexico have worked …


A Geospatial Decision Support System For Drought Risk Management, Steve Goddard, Jitender Deogun, Sherri K. Harms, Michael J. Hayes, Kenneth G. Hubbard, Stephen Reichenbach, Peter Revesz, W. J. Waltman, Donald A. Wilhite Jan 2004

A Geospatial Decision Support System For Drought Risk Management, Steve Goddard, Jitender Deogun, Sherri K. Harms, Michael J. Hayes, Kenneth G. Hubbard, Stephen Reichenbach, Peter Revesz, W. J. Waltman, Donald A. Wilhite

National Drought Mitigation Center: Faculty Publications

Drought affects virtually all regions of the world and results in significant economic, social, and environmental impacts. The Federal Emergency Management Agency estimates annual drought-related losses in the United States at $6-8 billion, which is more than any other natural hazard. Congress enacted the Agricultural Risk Protection Act of 2000 to encourage the United States Department of Agriculture (USDA) Risk Management Agency (RMA) and farmers to be more proactive in managing drought risk. Through the National Science Foundation (NSF) Digital Government program, the USDA RMA is working with the University of Nebraska−Lincoln Computer Science and Engineering (CSE) Department, National Drought …


Inorganic Nitrogen Transformations At High Loading Rates In An Oligohaline Estuary, R. Eugene Turner, Q. Dortch, Nancy N. Rabalais Jan 2004

Inorganic Nitrogen Transformations At High Loading Rates In An Oligohaline Estuary, R. Eugene Turner, Q. Dortch, Nancy N. Rabalais

Faculty Publications

A well-defined nitrogen retention and turnover budget was estimated for a shallow oligohaline lake (Lake Pontchartrain, Louisiana, USA). In 1997 a month-long diversion of the Mississippi River filled the Lake with highly concentrated river water (80 µM nitrate) and lowered the salinity to 0 psu within 2 weeks. After the spillway was closed the Lake mixed with estuarine tidal waters and came to equilibrium over 4 months with the riverine, atmospheric and offshore water nitrogen sources. A flushing rate of 1.78% d−1 was estimated by analyzing a plot of ln salinity versus time for the first 120 days after the …


Suspended Sediment, C, N, P, And Si Yields From The Mississippi River Basin, R. Eugene Turner, Nancy N. Rabalais Jan 2004

Suspended Sediment, C, N, P, And Si Yields From The Mississippi River Basin, R. Eugene Turner, Nancy N. Rabalais

Faculty Publications

The annual loads of C,N,P, silicate, total suspended sediment (mass) and their yields (mass area−1) were estimated for six watersheds of the Mississippi River Basin (MRB) using water quality and water discharge records for 1973 to 1994. The highest load of suspended sediments is from the Missouri watershed (58 mt km2 yr−1), which is also the largest among the six major sub-basins. The Ohio watershed delivers the largest load of water (38%). The Upper Mississippi has the largest total nitrogen load (32%) and yield (1120 kg TN km2 yr−1). The loading of organic carbon, total phosphorus and silicate from the …


Below-Ground Biomass In Healthy And Impaired Salt Marshes, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee, Thomas A. Oswald Jan 2004

Below-Ground Biomass In Healthy And Impaired Salt Marshes, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee, Thomas A. Oswald

Faculty Publications

Twelve salt marshes in south Louisiana (USA) were classified as either ‘impaired’ or ‘healthy’ before a summer sample collection of above- and below-ground biomass and determination of sediment accretion rates. The above-ground biomass of plant tissues was the same at both impaired and healthy salt marshes and was not a good predictor of marsh health. However, below-ground root biomass in the upper 30 cm was much lower in the impaired marshes compared to the healthy marshes. Compromises to root production apparently occur before there is an obvious consequence to the above-ground biomass, which may quickly collapse before remedial action can …


Water Quality Assessment: A Hands-On Approach To Environmental Education, Tracy Lynn Royse Jan 2004

Water Quality Assessment: A Hands-On Approach To Environmental Education, Tracy Lynn Royse

All Graduate Projects

A water quality assessment lab manual has been created to assist secondary educators using the HACH water quality testing kits. It consists of ten chemical tests, a geological survey and a biological assessment largely based upon Washington State University's lab format and the Walla Walla County Conservation District's water study protocol. The lab manual also contains safety guidelines, a scoring rubric and an action plan research project. The environmental approach to science education used in the lab manual meets the Essential Academic Learning Requirements adopted by the Washington State Commission on Student Learning as well as the National Science Education …


Mudfish On The Menu? Rise Of The Much-Maligned Bowfin, Ken Sulak Jan 2004

Mudfish On The Menu? Rise Of The Much-Maligned Bowfin, Ken Sulak

United States Geological Survey: Staff Publications

Cajuns call it “choupique” (say “shoe-pick”), from its Choctaw name. Elsewhere, it’s the dogfish, blackfish, grindle, cottonfish, or cypress trout. Its official common name is “Bowfin” (Amia calva)1. But to most anglers, this is the “mudfish,” a strange, unusual, and much-maligned fish, most everywhere considered a useless trash fish. One look and the words relict, prehistoric, primitive, and living fossil come to mind. Indeed, the bowfin is the last of its line, the sole-surviving species of a very ancient group of fishes. Its predecessors flourished in the Jurassic and Cretaceous periods during the Mesozoic (= Middle-Animal) Era, a …


Habitat Preferences And Diving Behavior Of White Marlin (Tetrapturus Albidus) Released From The Recreational Rod-And-Reel And Commercial Pelagic Longline Fisheries In The Western North Atlantic Ocean: Implications For Habitat-Based Stock Assessment Models, Andrij Horodysky, David W. Kerstetter, John E. Graves Jan 2004

Habitat Preferences And Diving Behavior Of White Marlin (Tetrapturus Albidus) Released From The Recreational Rod-And-Reel And Commercial Pelagic Longline Fisheries In The Western North Atlantic Ocean: Implications For Habitat-Based Stock Assessment Models, Andrij Horodysky, David W. Kerstetter, John E. Graves

Marine & Environmental Sciences Faculty Reports

To improve billfish assessments, researchers have applied habitat-based models that incorporate behavioral and oceanographic parameters to standardize historical catch-per-uniteffort time -series data, accounting for significant gear changes over time. However, there has been little behavioral data from Atlantic billfishes to support these models. We provide information on habitat preferences of white marlin released from recreational and commercial fisheries in the western North Atlantic. White marlin were tagged with pop-up satellite archival tags (PSATs) from recreational rod and reel (n=22) and commercial pelagic longline (n=2) fisheries between May-November 2002. Our data indicate that each surviving white marlin spent the majority of …


Sea Turtle Conservation Program, Broward County, Fl 2004 Report, Curtis M. Burney, Stefanie Ouellette Jan 2004

Sea Turtle Conservation Program, Broward County, Fl 2004 Report, Curtis M. Burney, Stefanie Ouellette

Marine & Environmental Sciences Faculty Reports

No abstract provided.


Microfauna As Tracers Of Sediment Transport: Ft. Pierce Dredge Spoils Sediment Study, Patricia Blackwelder, Carlos Alvares Zarikian, Terry Hood, Charles M. Featherstone, John Proni, Jules Craynock Jan 2004

Microfauna As Tracers Of Sediment Transport: Ft. Pierce Dredge Spoils Sediment Study, Patricia Blackwelder, Carlos Alvares Zarikian, Terry Hood, Charles M. Featherstone, John Proni, Jules Craynock

Marine & Environmental Sciences Faculty Reports

No abstract provided.


Diel Activity Patterns, Space Utilization, Seasonal Distribution And Population Structure Of The Yellow Stingray, Urobatis Jamaicensis (Cuvier, 1817) In South Florida With Comments On Reproduction., Daniel P. Fahy Jan 2004

Diel Activity Patterns, Space Utilization, Seasonal Distribution And Population Structure Of The Yellow Stingray, Urobatis Jamaicensis (Cuvier, 1817) In South Florida With Comments On Reproduction., Daniel P. Fahy

HCNSO Student Theses and Dissertations

The yellow stingray, Urobatis jamaicensis is the most common elasmobranch in the coastal waters of Southeast Florida. Despite their common occurrence the ecology of yellow stingrays remains poorly understood. In particular, yellow stingray daily movements, space utilization, seasonal distribution and population structure have not been described. This study was conducted to address the lack of knowledge of these fundamental life history parameters and to provide further information on the ecology of U. jamaicensis in coastal waters of Broward County, Florida.

The activity patterns and space utilization of U. jamaicensis were assessed by manual tracking with ultrasonic telemetry. Telemetry tracking of …


Atmospheric Variability Of Methyl Chloride During The Last 300 Years From An Antarctic Ice Core And Firn Air, M. Aydin, Eric S. Saltzman, Warren J. De Bruyn, S. A. Montzka, J. H. Butler, M. Battle Jan 2004

Atmospheric Variability Of Methyl Chloride During The Last 300 Years From An Antarctic Ice Core And Firn Air, M. Aydin, Eric S. Saltzman, Warren J. De Bruyn, S. A. Montzka, J. H. Butler, M. Battle

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Measurements of methyl chloride (CH3Cl) in Antarctic polar ice and firn air are used to describe the variability of atmospheric CH3Cl during the past 300 years. Firn air results from South Pole and Siple Dome suggest that the atmospheric abundance of CH3Cl increased by about 10% in the 50 years prior to 1990. Ice core measurements from Siple Dome provide evidence for a cyclic natural variability on the order of 10%, with a period of about 110 years in phase with the 20th century rise inferred from firn air. Thus, the CH3Cl increase measured in firn air may largely be …


(Under)Mining The Seabed? Between The International Seabed Authority Mining Code And Sustainable Bioprospecting Of Hydrothermal Vent Ecosystems In The Seabed Area: Taking Precaution Seriously, Ikechi Mgbeoji Jan 2004

(Under)Mining The Seabed? Between The International Seabed Authority Mining Code And Sustainable Bioprospecting Of Hydrothermal Vent Ecosystems In The Seabed Area: Taking Precaution Seriously, Ikechi Mgbeoji

Articles & Book Chapters

Rapid developments in marine biotechnology and the prospect of sea-bed mining have exposed the inadequacy of legal frameworks to regulation the exploration exploitation, and sharing of the benefits that arise from such marine endeavors. The fact of the matter is that despite the giant strides made in and the huge financial stakes involved in bioprospecting of hydro-thermal vent ecosystems, legal issues raised by profitable biotechnology development through marine scientific research (MSR) are still at an infant and underdeveloped stage. This article evaluates the extent to which the present legal order for the mining of seabed polymetallic nodules with its tangential …


Winter 2004, Nsu Oceanographic Center Jan 2004

Winter 2004, Nsu Oceanographic Center

Currents

No abstract provided.


Summer 2004, Nova Southeastern University Jan 2004

Summer 2004, Nova Southeastern University

Currents

No abstract provided.


Stable Isotopic And Trace Metal Analyses Of Two Porites Lobata Colonies - Oahu, Hawaii: Implications For Past Seasonal Variation And Sea Surface Temperatures And Anthropogenic Effects On The Reef Environment, Jonathan Macdonald Jan 2004

Stable Isotopic And Trace Metal Analyses Of Two Porites Lobata Colonies - Oahu, Hawaii: Implications For Past Seasonal Variation And Sea Surface Temperatures And Anthropogenic Effects On The Reef Environment, Jonathan Macdonald

Geology Theses and Dissertations

Corals from the western and equatorial Pacific Ocean have been extensively studied for the purposes of generating paleoclimate reconstructions spanning the last several hundred years. However, in the central subtropical North Pacific, there are currently few published coral records extending beyond 10 to 20 years. The hermatypic coral species Porites lobata and Porites lutea have proven to be useful indicators of paleoclimate and past sea surface conditions at other locations. Here I have analyzed two Porites lobata coral cores collected from colonies from opposite sides of Oahu, Hawaii to assess their utility for developing multi-decadal length climatic reconstructions in this …


Sources Of Ancient Maize Found In Chacoan Great Houses, Larry Benson Jan 2004

Sources Of Ancient Maize Found In Chacoan Great Houses, Larry Benson

United States Geological Survey: Staff Publications

Between the 9th and 12th centuries A.D., Chaco Canyon, located near the middle of the high-desert San Juan Basin of north-central New Mexico (fig. 1), was the focus of an unprecedented construction effort by pre-Columbian Native Americans. It has been estimated that from 2,000 to 6,000 people occupied Chaco Canyon during its heyday (Windes, 1984; Drager, 1976). One indication of Chaco’s regional importance is a network of roads that linked Chaco Canyon with other great houses and communities spread throughout a region covering at least 60,000 km2 (fig. 2). At the height of its cultural florescence in the 11th century, …


Modeled And Observed Empirical Orthogonal Functions Of Currents In The Yucatan Channel, Gulf Of Mexico, Lie-Yauw Oey, Tal Ezer, Wilton Sturges Jan 2004

Modeled And Observed Empirical Orthogonal Functions Of Currents In The Yucatan Channel, Gulf Of Mexico, Lie-Yauw Oey, Tal Ezer, Wilton Sturges

CCPO Publications

Candela et al. [2003] have reported empirical orthogonal function (EOF) analyses based on 23-month current-meter and acoustic Doppler current profiler measurements in the Yucatan Channel. Those authors noted the difference between EOFs obtained from observations and their z-level models and EOFs calculated by Ezer et al. [2003] from the results of a terrain-following model. Here a new analysis is reported that explains this difference, and that also suggests the importance of shelf-edge meander mode of the core Loop Current in the channel. We show that the terrain-following model gives EOFs with characteristics similar to those observed when data from the …


Numerical Study Of The Diapycnal Flow Through A Tidal Front With Passive Tracers, Chingming Dong, Robert Houghton, Hsien-Wang Ou, Dake Chen, Tal Ezer Jan 2004

Numerical Study Of The Diapycnal Flow Through A Tidal Front With Passive Tracers, Chingming Dong, Robert Houghton, Hsien-Wang Ou, Dake Chen, Tal Ezer

CCPO Publications

A two-dimensional numerical model is used to study the diapycnal flow through a tidal front with passive tracers. In a basic numerical experiment a passive tracer is released into the bottom water at the offshore edge of a tidal front, and it subsequently moves on-bank with a velocity that decreases with time. This qualitatively agrees with a recent field experiment using a dye tracer on Georges Bank. Additional experiments are performed to investigate the sensitivity of the tracer dispersion to the tidal phase and the location of tracer release within the front. As the release point is moved on-bank across …


Simulations Of The Influence Of The West Caribbean Sea Circulation And Eddies On The Meso-American Barrier Reef System, Tal Ezer, Deeptha V. Thattai, Björn Kjerve Jan 2004

Simulations Of The Influence Of The West Caribbean Sea Circulation And Eddies On The Meso-American Barrier Reef System, Tal Ezer, Deeptha V. Thattai, Björn Kjerve

CCPO Publications

The Meso-American Barrier Reef System (MBRS) along the coasts of Mexico, Belize, Guatemala, and Honduras is an ecologically and biologically sensitive region. It provides for example, major spawning aggregation sites for various species of fish; these activities may be influenced by variations of the flow near the reef and the transports between the MBRS and the Caribbean Sea circulation. Caribbean eddies, which may play an important role in flow variability, have been studied in the past by observations and models (Carton and Chao, 1999; Murphy et al., 1999; Andrade and Barton, 2000; Oey et al., 2003), but knowledge of their …


On The Sensitivity Of The West Caribbean Sea Circulation To Tides, Wind, And Mesoscale Ocean Eddies: A Three-Dimensional Ocean Model Study, Deeptha V. Thattai, Tal Ezer, Bjorn Kjerfve Jan 2004

On The Sensitivity Of The West Caribbean Sea Circulation To Tides, Wind, And Mesoscale Ocean Eddies: A Three-Dimensional Ocean Model Study, Deeptha V. Thattai, Tal Ezer, Bjorn Kjerfve

CCPO Publications

A three-dimensional, primitive equation ocean model is used to study the circulation in the West Caribbean Sea (WCS) region, and to test the sensitivity of the coastal flow to various forcing fields such as tides, climatological wind, and Caribbean eddies. The model domain is bordered by latitudes 15 – 22 degrees N and longitudes 76 – 87 degrees W, with the MesoAmerican Barrier Reef System (MBRS, along the coasts of Mexico, Belize, Guatemala, and Honduras) and the southern coast of Cuba as land boundaries. The WCS is open to the Caribbean Sea in the southeast and the Yucatan Channel in …


Satellite Evidence Of Hurricane-Induced Phytoplankton Blooms In An Oceanic Desert, S. M. Babin, J. A. Carton, T. D. Dickey, J. D. Wiggert Jan 2004

Satellite Evidence Of Hurricane-Induced Phytoplankton Blooms In An Oceanic Desert, S. M. Babin, J. A. Carton, T. D. Dickey, J. D. Wiggert

CCPO Publications

The physical effects of hurricanes include deepening of the mixed layer and decreasing of the sea surface temperature in response to entrainment, curl-induced upwelling, and increased upper ocean cooling. However, the biological effects of hurricanes remain relatively unexplored. In this paper, we examine the passages of 13 hurricanes through the Sargasso Sea region of the North Atlantic during the years 1998 through 2001. Remotely sensed ocean color shows increased concentrations of surface chlorophyll within the cool wakes of the hurricanes, apparently in response to the injection of nutrients and/or biogenic pigments into the oligotrophic surface waters. This increase in post-storm …


Advection, Krill, And Antarctic Marine Ecosystems, Eileen E. Hofmann, Eugene J. Murphy Jan 2004

Advection, Krill, And Antarctic Marine Ecosystems, Eileen E. Hofmann, Eugene J. Murphy

CCPO Publications

Advective processes are recognized as being important in structuring and maintaining marine ecosystems. In the Southern Ocean advective effects are perhaps most clearly observed because the Antarctic Circumpolar Current (ACC) provides a connection between most parts of the system, including open ocean and continental shelf regions. The ACC also provides a mechanism for large-scale transport of plankton, such as Antarctic krill (Euphousia superba Dana), which is an important component of the Southern Ocean food web. This overview provides a summary of recent observational and modelling results that consider the importance of advection to the Southern Ocean ecosystem and, in particular, …


Vemap Phase 2 Bioclimatic Database. I. Gridded Historical (20th Century) Climate For Modeling Ecosystem Dynamics Across The Conterminous Usa, T. G. F. Kittel, N. A. Rosenbloom, J. A. Royle, C. Daly, W. P. Gibson, H. H. Fisher, P. Thornton, D. N. Yates, C. Kaufman, R. Mckeown, D. Bachelet, D. S. Schimel, Steven W. Running, Vemap2 Participants Jan 2004

Vemap Phase 2 Bioclimatic Database. I. Gridded Historical (20th Century) Climate For Modeling Ecosystem Dynamics Across The Conterminous Usa, T. G. F. Kittel, N. A. Rosenbloom, J. A. Royle, C. Daly, W. P. Gibson, H. H. Fisher, P. Thornton, D. N. Yates, C. Kaufman, R. Mckeown, D. Bachelet, D. S. Schimel, Steven W. Running, Vemap2 Participants

Ecosystem and Conservation Sciences Faculty Publications

Analysis and simulation of biospheric responses to historical forcing require surface climate data that capture those aspects of climate that control ecological processes, including key spatial gradients and modes of temporal variability. We developed a multivariate, gridded historical climate dataset for the conterminous USA as a common input database for the Vegetation/Ecosystem Modeling and Analysis Project (VEMAP), a biogeochemical and dynamic vegetation model intercomparison. The dataset covers the period 1895-1993 on a 0.5° latitude/longitude grid. Climate is represented at both monthly and daily timesteps. Variables are: precipitation, mininimum and maximum temperature, total incident solar radiation, daylight-period irradiance, vapor pressure, and …


Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal Jan 2004

Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal

Mathematics, Physics, and Computer Science Faculty Articles and Research

The possibility that rising atmospheric CO2 concentrations are influencing plant growth in contemporary ecosystems has received little attention, and the studies that exist have been done on a small spatial scale. We correlated the monthly rate of relative change in normalized differenced vegetation index (NDVI) from advanced very high resolution radiometer (AVHRR) data to the rate of change in atmospheric CO2 concentration during the natural vegetation growing season for evidence of a possible CO2 fertilization effect on vegetation development. The study addressed seasonal and annual patterns in spatially averaged NDVI for 3 different ecological regions in North America from 1982 …


Method Analysis Of Laboratory Measures Of Stream Sediment And Water Phosphorus Equilibrium, Anna L. Erickson, Stephanie M. Williamson, Brian E. Haggard Jan 2004

Method Analysis Of Laboratory Measures Of Stream Sediment And Water Phosphorus Equilibrium, Anna L. Erickson, Stephanie M. Williamson, Brian E. Haggard

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Elevated phosphorus concentrations in aquatic ecosystems of northwest Arkansas prompted an investigation of the effects of sample preparation and extraction methods on laboratory measures of sediment-phosphorus interactions. Two streams of contrasting phosphorus (P) concentrations were selected to determine the effect of using a CaCl2 solution instead of filtered stream water, refrigerated or dried sediments instead of fresh wet sediments, and vortexing the suspensions instead of shaking them. Sediment equilibrium P concentration (EPC0) and P buffering capacity (K) were used to determine differences in extraction methods. EPC0 and K from extractions using fresh sediments and a CaCl2 solution matching the electrical …