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2004 Progress Report: Louisiana Environmental Research Center
EPA Grant Number: R829584Center: Louisiana Environmental Research Center (McNeese State)
Center Director: Ford, Mark A.
Title: Louisiana Environmental Research Center
Investigators: Ford, Mark A. , Stacy, Gus
Institution: McNeese State University
EPA Project Officer: Stelz, Bill
Project Period: February 1, 2002 through January 31, 2007
Project Period Covered by this Report: February 1, 2003 through January 31, 2004
Project Amount: $1,334,900
RFA: Targeted Research Center (2004)
Research Category: Hazardous Waste/Remediation , Targeted Research
Description:
Objective:Louisiana continues to lose wetlands at an alarming rate. This crisis is of national significance and will have devastating impacts on Louisiana and the nation. Wetlands are lost as a result of subsidence, saltwater intrusion, sea level rise, herbivores, oil or chemical spills, and many other natural or man-induced factors. Highly productive vegetated wetlands are being converted to unproductive open water at the rate of a parcel the size of a football field every 30 minutes.
Approximately 35 square miles are being lost annually. The Governor’s Committee on the Future of Coastal Louisiana reports that without the wetlands, tens of billions of dollars will be lost to the state and nation. The benefits of wetlands include: storm protection, protection of oil and gas networks, protection of transportation networks, water quality, fisheries, protection of coastal communities and infrastructure, protection of unique world renowned ecosystems, and many intangible values.
The Louisiana Environmental Research Center (LERC) was created in 1990 to conduct basic research, accumulate and disseminate information, and create awareness through education of environmental issues and concepts related to wetlands restoration/remediation. LERC’s studies and research are directed at wetland restoration, ecology, and the environmental effects of oil spills.
Louisiana’s coastal area is generally divided into two geographic sections: the western area called the Chenier Plain and the eastern area called the Deltaic Plain. The Chenier Plain is dominated by old beach lines and ridges indicating that the sea is the dominant force shaping the region. The Deltaic Plain is dominated by the Mississippi River and the deltaic processes, which are ongoing but have been interrupted by man’s activities. Many of the restoration techniques differ in the two regions. LERC research is directed at Chenier Plain restoration techniques, although much of LERC’s work has applications in both regions.
LERC’s research focus has been on newly created wetlands on the Sabine National Wildlife Refuge, south of Lake Charles. The Calcasieu Ship Channel is periodically dredged to allow ship traffic to navigate from the mouth of Calcasieu Pass to the industries at Lake Charles. The U.S. Army Corps of Engineers has used the dredged material to fill open water areas, creating new marsh sites. The first site created was finished in 1983. It was the first experimental use of restoring wetlands in the Calcasieu River Basin using dredged material. Four additional areas have been levied and filled with dredged material, creating a living laboratory for LERC scientists to study restoration sites of various ages. The years the sites were created and the sizes are as follows:
1993 - 665 acres
1996 - 425 acres
1999 - 274 acres
2002 - 205 acres
The objective of this research project is to research restoration techniques to return open water unproductive areas to productive vegetated wetlands. Regardless of what kills the vegetation, subsidence, sea level rise, saltwater intrusion, oil or chemical spills, dredging canals, or other factors, the knowledge gained from LERC’s researchers will help guide wetlands managers and decisionmakers as restoration efforts increase.
Project Objectives
Our research program consists of seven projects, which are described below.
Project 1: EPA Project IV—Wetlands Restoration and Remediation in Southwest Louisiana Marshes: A Study Of Soil Elevation, Vertical Accretion, Shallow Subsidence And Root Zone Influences in Marshes Restored Using a Variety of Techniques. Restoration using dedicated dredged materials will be studied. Our question is, “Can restored marshes function like natural marshes?” Marsh restoration will be assessed by studying five marshes restored using dedicated dredged material whose ages range from less than 1 year to 19 years. Variables of root zone tissue primary production (biomass and volume), soil surface relative elevation, and vertical soil accretion will be examined to determine influencing factors on the success and long-term survival of restored march elevations.
Project 2: Developing Methods for Identifying Suitable Donors for Wetland Plant Restoration Through Transplantation. To determine the appropriateness of restoring wetlands by transplanting Spartina alterniflora from distant sites as is commonlypracticed.
Project 3: Effects of Salinity and Bottom Substrate Composition on the Growth and Proliferation of Widgeongrass (Ruppia maritima). The growth and proliferation of widgeongrass is affected by various factors such as sunlight, temperature, and salinity. In the sulfur-rich, organic bottom substrate of Gulf of Mexico tidal marshes, widgeongrass growth and proliferation is hindered severely at salinities of 12-15 ppt. In the sandy soils of the coastal bend of Gulf bays, however, widgeongrass thrives at salinities of 25 ppt. This salinity- and bottom substrate-dependent growth has not been characterized fully. The differences in salt-tolerance likely are dependent on the soil reduction-oxidation potential of the two different types of bottom substrate. The objectives of this project are to determine the effects that salinity and bottom substrate composition contribute to widgeongrass growth. Also, we are attempting to conduct genetic analyses using specific genomic markers to determine if genetic drift has occurred between R. maritima stands that grow in different environments and in different states across the Gulf Coast.
Project 4: A Comparison of Health Parameters and Parasites in the Marsh Rice Rat Oryzomys palustris From Natural Freshwater, Saltwater, and Restored Marshes in the Sabine National Wildlife Refuge. The objective of this project is to examine the overall health of marsh rice rats living in natural and restored saltwater (brackish) marshes, as well as freshwater marshes in the Sabine National Wildlife Refuge. Through the analysis of hematological, immunological, and hepatological measurements, as well as the examination of endoparasites and ectoparasites, we will determine if populations of rice rats living in any of these habitats may be less able to meet physiological challenges than those living in other types of habitats.
Project 5: Comparison of Metal Concentrations in Soils, Sediments, and Selected Species From the Area Around Chevron Texaco No. 2 Bayou Tank Battery in the Sabine National Wildlife Refuge in Southwest Louisiana and Preliminary Determination of Oxidation State (Species) of Selected Metals From Soils and Sediments in the Immediate Area Around Chevron Texaco No. 2 Bayou Tank Battery in the Sabine National Wildlife Refuge in Southwest Louisiana and in Laboratory-Controlled Burns. This research will collect soil and sediment samples from a crude oil spill site that was remediated by a controlled burning in the Sabine Wildlife National Refuge in Southwest Louisiana for determination of selected metals: vanadium, nickel, manganese, and zinc. A preliminary study of metal speciation (oxidation state) in these soils for Vanadium will be pursued using X-Ray Absorption Near Edge Spectroscopy (XANES) at the nearby Center for Advanced Materials (CAMD) in Baton Rouge.
Project 6: Use of The Prairie Garden and Plant Material Center To Collect, Propagate, and Maintain Breeder Blocks and Garden Specimens of Louisiana Prairie And Wetland Ecotypes. Existing breeder blocks of black wand root, cluster bushmint, rattlesnake master, hoary pea, marsh mallow, and little blue stem were maintained and seed was collected and forwarded to the Natural Resources Conservation Service (NRCS) Plant Material Center in Golden Meadow, Louisiana.
The objectives of the conservatory have been met for the first year. Breeder blocks were maintained for outreach education and plant material conservation. Records are being kept on species maintained in the breeder blocks and garden area as recommended by the NRCS and U.S. Geological Survey (USGS).
The objectives of the conservatory are to: (1) collect, propagate, and maintain breeder blocks of Louisiana ecotypes for outreach education; (2) collect, propagate, and maintain breeder blocks of Louisiana ecotypes for prairie re-establishment; (3) develop foundational knowledge for future research concerning prairie conservation; and (4) enhance the ongoing, collaborative efforts of academia, government, and private agencies to reestablish the prairie.
Project 7: Density of Marsh Periwinkles and Fire Ant Mounds in Natural and Restored Marshes in the Sabine National Wildlife Refuge. The objectives of this project are to:(1) assess variation in periwinkle (snail) density among marshes differing in the degree of restoration; and (2) determine if there is a relationship between the densities of periwinkles and fire ant mounds.
Progress Summary:Project 1
The dedicated dredge material sites (Browns Lake, 1983, 1993, 1996, 1999) and Hog Island Gully reference marsh sites were sampled for Sediment-Erosion Table elevation changes, sediment accretion, and below ground root volume in February, May, August, and November of 2004. Results from the 2-year project currently are going through a quality control and analysis.
Preliminary results do not indicate that the root zone development of the reference marsh is influencing the change in elevation at the reference marsh site. Preliminary analysis on the restored sites indicates much of the same pattern as the reference marsh. Sediment accretion on the sites appears to be deficient to prevent shallow subsidence impacts to the restored and natural marshes of the area. Subsidence is defined as elevation change versus surface accretion. The 1999 restored marsh site varies in landscape, and thus, a large amount of surface erosion was noted during the course of the project. The potential erosion could lead to the increased elevation change and decreased accretion rate.
Project 2
This project seeks to determine the appropriateness of restoring wetlands by transplanting S. alterniflora from distant sites, as is commonly practiced. Specifically, this project seeks to determine the relationship between adaptability to the restoration site and distance to the donor site using a common-garden approach. In addition, all donors used in this experiment are being genotyped to determine if the adaptability of potential donors can be assessed on the basis of genetic similarity to plants growing in the vicinity of the restoration site. Living plant material was gathered from 25 marsh sites spanning the Northern Gulf and Atlantic Coasts of the United States for transplantation to an experimental site in Louisiana. Each donor site was sampled for both plant tissue and pertinent environmental variables. Living plant material (8 clones per donor site) was acclimated over-winter in a greenhouse prior to planting at the experimental site. Measurements of photosynthetic rate, survivorship, clone diameter, and mean stem height and basal width were taken at monthly intervals throughout two consecutive growing seasons.
Preliminary results have demonstrated a clear negative relationship between latitude and photosynthetic rate, survivorship, and growth. In addition, results show that performance for both photosynthetic rate and survivorship drops off precipitously for donor plants collected at latitudes of greater than 30-35 degrees north.
All genotyping and field activities for this project are complete. Data analyses are ongoing.
Project 3
Our initial results from the widgeongrass genetic project have revealed that inverted terminal repeat sequences (ITRS) genetic markers will be useful tools for the analysis of this plant species. We are in the process of collecting samples from different locations that reflect different salinities. These samples will be used for sequence comparisons of the ITRS regions.
We successfully have grown stock cultures of widgeongrass in subterranean 110-gallon stock tanks. The cultures are healthy and will be used to seed the subcultures for the project on the effects of the salinity and bottom substrate. The subculture buckets have been prepared using the various bottom substrates and are ready to be seeded with widgeongrass. A platform (8’x16’) for this experiment has been built that features a frame to hold the 17 fluorescent light fixtures (34 40-watt, 48” bulbs). This project is expected to begin early in the summer of 2005.
Project 4
During Year 1 of the project, we have begun collecting tissues from rice rats from both natural and restored marsh habitats. Rice rat collection will continue through the summer and should be completed by November or December 2005. Collection of data from the tissue samples will be completed by early 2006.
This project is still ongoing, and therefore, we have no definitive results to report. We can report, however, that no evidence has been found of the rodent lungworm (Angiostrongylus cantonenesis) in the samples examined thus far. Hematological and immunological data are still being collected and a full report of our results should be available in next year’s annual report.
Project 5
Results indicate that a controlled burning of an oil spill will not contaminate the soil with the metals (from the crude oil) investigated in this study (vanadium, zinc, manganese, and nickel).
Samples were collected in mid-December 2002 and summer 2003. A method was developed for sampling eight areas (some near and some far away from the site) at various depths, typically up to 25 cm. The samples were digested using a microwave digestion method for subsequent determination by inductively coupled plasma-atomic emission spectrometry (ICP-AES). Quality control/quality assurance was achieved using various National Institute of Standards and Technology and U.S. Environmental Protection Agency samples, spiking, and recoveries, and the results obtained statistically were the same as the certified values. The ICP-AES method was monitored continuously for accuracy using certified samples, as well as acceptable precision. Results for the metals determined showed an expected variation in metal concentrations but, more importantly, showed that the controlled burning did not increase the metal concentrations in the soils. A planned and final sampling will be used to confirm this hypotheses and a more detailed report will be prepared from the final submission. Preliminary results from CAMD on the oxidation states for vanadium were very promising in that we clearly could tell the difference between V3+, V5+, and V0. The XANES method could work around the detection limit of 20 parts per million (ppm) that was found in the soil.
Project 6
In conjunction with the NRCS Plant Materials Center and USGS Wetland Research Center, the Coastal Prairie Conservatory is collecting, propagating, and maintaining selected Louisiana coastal wetland and prairie plant ecotypes (Louisiana ecotypes). During 2004, conservatory personnel collected and maintained the breeder blocks and constructed the prairie garden area, which is located at LERC. In addition, the conservatory provided outreach education for local schools by giving presentations to local schools and holding environmental education events.
The prairie garden was completed on June 18, 2004. The garden was designed to facilitate plant water needs that were based on the wetland indicator status (e.g., upland, facultative upland, facultative, facultative wet, and obligate wetland species), which indicates species-specific hydrologic need. Therefore, each Louisiana ecotype was maintained in conditions that mimic natural hydrologic conditions. Currently, 55 species have been transplanted to the garden area.
Fourteen species have been established as partial and whole foundation blocks at the off-station plant materials site known as the Kyouche Tract. This initiative was a result of the collaborative efforts of the Coastal Plains Conservatory, NRCS, USGS, McNeese Agriculture Department, and LERC. Overall, approximately 800 primary, secondary, and university students and teachers participated in the outreach education opportunities presented by LERC personnel.
Eight McNeese State University environmental science students participated in a seminar that focused on wetland delineations and permits in the Louisiana coastal plain. Focus was placed on the coastal prairie and marsh habitats of Southwest Louisiana. Four-hundred primary and secondary students and teachers from Southwest Louisiana participated in the Wetland Awareness Campaign. LERC researchers participated in the collaborative effort with the Coalition to Restore Coastal Louisiana. Some of the agencies that participated were LERC, NRCS, USGS, the Louisiana Department of Agriculture, the Louisiana Department of Natural Resources, and the McNeese Wildlife Club. LERC maintained an outreach booth and participated in the Conservation Education Maze in the Civic Center Arena. Twenty McNeese wildlife management students participated in a hands-on workshop to collect cluster bushmint, black wandroot, and marsh mallow seeds. They collected seeds just prior to a pending tropical storm and learned the importance of the prairie to wildlife and the current prairie conservation initiative. Fifty students at College Oaks Elementary School participated in a presentation and discussion on the research efforts concerning coastal prairie and marsh conservation. LERC personnel presented the Prairie Garden Outreach Program to the Calcasieu Parish School Board and the Science Incentive Program Science Teacher Program. The purpose of the program was to develop the initial network between the school board and the Coastal Prairie Outreach Program. Six board members attended the presentation. As a result, teacher contacts were provided by the school board for future presentations. The 20 McNeese wildlife management students participated in a hands-on workshop to collect little bluestem seeds and assist with maintenance work on the breeder blocks. The workshop served as the final seed collection for 2004 and provided a discussion on the importance of the prairie plant community diversity and wildlife species richness. LERC personnel participated in a television interview with KPLC and Sabine National Wildlife Refugee. The subject of discussion was the importance of the coastal ecosystem and conservation of those resources, which included the importance of the coastal prairie in the headwaters of the Southwest Louisiana riverine system. One-hundred students from College Oaks participated in a field trip to Sabine National Wildlife Refuge. LERC representatives provided assistance and presented the ongoing marsh and prairie efforts at LERC. Ninety students at Dolby Elementary School participated in a presentation and discussion on the research efforts concerning coastal prairie and marsh conservation. One-hundred students at College Elementary School participated in Wetland Play, which was a hands-on learning exercise in the coastal prairie and marshes.
Project 7
Three sites (one natural and two restored marshes) have been sampled three times (December 2004, February 2005, and May 2005). Periwinkles and fire ant mounds have been enumerated from 108 plots in 18 transects. The three sites will be visited on three more dates.
Our data so far indicate that the marsh periwinkle is not present at the restored marsh sites. At the natural marsh site, marsh periwinkles have been present in very low densities (to date 0.4 snails/plot). On the first two sampling dates (December 2004 and February 2005), active fire ant mounds were found in the oldest restored marsh. On the third sampling date (May 2005), active fire ant mounds were found in the more recently restored marsh.
Completed Project Update
Productivity and Carbon Sequestration in Created and Natural Salt Marshes. The object is to determine if created salt marshes, made from dredged material, are on a trajectory to become functionally equivalent to natural marshes.
Comparison of Wetland Structural Characteristics between Created and Natural Salt Marshes. Vegetation and soil structural factors were compared to determine if the created marshes become more similar over time to the surrounding natural salt marshes. Vegetation surveys were conducted in 1997, 2000, and 2002 using the line-intercept technique. Site elevations were measured in 2000. Organic matter was measured in 1996 and 2002, whereas bulk density and soil particle-size distribution were determined in 2002 only. The natural marshes were dominated by S. alterniflora, as were the oldest created marshes; these marshes had the lowest mean site elevations. The 6-year-old created marsh was higher in elevation and became dominated by high marsh and shrub species. The higher elevation marsh seems to be following a different plant successional trajectory than the other marshes, indicating a relationship between marsh elevation and species composition. The soils in both the created and natural marshes contain high levels of clay (30-65%), with sand comprising less than 1 percent of the soil distribution. Organic matter was significantly greater and bulk density significantly lower in the two natural marshes when compared to the created marshes. The oldest created marsh had significantly greater organic matter than the younger created marshes, but it may still take several decades before equivalency is reached with the natural marshes. Vegetation structural characteristics in the created marshes take only a few years to become similar to those in the natural marshes but only if the marshes are formed at a proper elevation.
Functional Equivalency of Above and Belowground Productivity for S. alterniflora (Smooth Cordgrass) in Natural and Created Salt Marshes. Primary productivity is an important function and indicator of success for salt marsh creation/restoration projects. The aim of this project was to determine whether the above- and belowground productivity of the dominant salt marsh grass S. alterniflora in created marshes in Southwest Louisiana began to approximate productivity levels in surrounding natural marshes over time. There are numerous studies of S. alterniflora but only a few that have compared productivity between natural and created salt marshes. No such comparative studies have been done in Louisiana until now.
Trajectories of ecological functions have been used by some researchers to determine the success of marsh creation projects. The main assumption behind the idea of trajectories, in terms of ecological restoration projects, is that the structure and/or functions of the created sites should begin to approximate those in natural reference habitats over time.
Net aboveground primary productivity (NAPP) was measured by harvest technique, whereas the ingrowth core method was used to estimate net belowground primary productivity (NBPP). As the created marshes aged, both above- and belowground productivity became similar to levels in the natural marshes.
NAPP levels of S. alterniflora in our project sites were similar to those found in other natural Louisiana salt marshes. NAPP in these studies ranged from 750 to 2,600 gDW/m2/year, depending on which method was used. As in our project, a study in 1990 used the Lomnicki method and estimated the NAPP in a natural Louisiana marsh to be 2,050 gDW/m2/year, which is similar to the mean NAPP value of the two natural sites in our project. NAPP was affected negatively by site age. The youngest sites were the most productive with the oldest created sites having the same productivity as one of the natural sites.
There was a trend of decreasing NAPP, however, as the created marshes aged, but these levels were still well above the mean NAPP values of the natural marshes, based on a relativized comparison. Equivalency in NAPP, however, has not been reached in the almost 20 years since these marshes were created. The decreasing trend was not significant, meaning that there has been little change in the aboveground productivity of the created marshes as they age relative to the natural marshes. At this rate, if would be approximately 35 years before the created marshes had NAPP levels equivalent to those found in the natural marshes.
NBPP increased from the youngest to the oldest created marshes, becoming equivalent to levels found in the natural marshes after 6 to 8 years. NBPP continued to increase with marsh age, reaching an asymptote that surpassed natural marsh levels. NBPP appears as though it may remain higher in the created marshes as they age, compared to the natural marshes.
There was an evident effect of elevation on both above- and belowground S. alterniflora productivity in our project sites. Elevation affected productivity, as higher sites had significantly lower above- and belowground biomass levels than those with elevations closer to mean sea level. Aboveground productivity was significantly negatively affected related to site elevation range, with sites that have a more heterogeneous topography having lower NAPP. Mean site elevation also was found to be a significant factor affecting NBPP, which was lowest in marshes with higher mean elevation. Lower production levels indicate the presence of stress factors, such as high salinity. Greater stress, as a result of high salinity levels, will lead to reduced growth of S. alterniflora and, thus, decreased productivity. This underscores the need to construct marshes so their mean elevation and degree of topography heterogeneity are similar to natural marshes.
Future productivity measurements will be needed, at a maximum 5-year interval, to determine if or when equivalency is attained. The lower productivity of S. alterniflora found in some of the created marshes of the same age was a result of their having higher final elevations. This emphasizes the importance, when creating or restoring salt marshes, of having physical traits that are similar to those of natural reference marshes for the restoration to be successful. Even then, decades may need to pass before equivalency between the created and reference natural marshes is reached.
Decomposition Rates of Spartina alterniflora in Dredge-filled Created and Natural Salt Marshes. Decomposition is an important factor that needs to be studied when comparing created and naturally occurring wetlands. We compared decomposition rates in marshes created from dredge material to the rates in natural reference salt marshes in the Sabine National Wildlife Refuge. We hypothesized that, as the created marshes age, the functions in these marshes will become similar to those in the natural marshes. Litter bags, which were filled with 10g of dead S. alterniflora material (7g stems, 3g leaves), were placed out in the sites in 2002. There were 5 replicate stations per site with 12 bags at each station. Two bags were collected from each station (10 per site) at 2-month intervals. Results show statistically significant differences in decomposition rates between created sites and reference sites. S. alterniflora decomposition occurred more quickly in created compared to reference marshes. Differences between reference and created marsh decomposition lessened as time progressed. The older created sites repeatedly had a faster rate of decomposition than the younger created sites. This further confirms the findings of the previous functional studies that the created marshes are becoming like natural marshes as time progresses.
Comparison of Available Nutrient Concentrations in Created and Natural Salt Marshes. Above- and belowground plant, soil, and porewater samples were analyzed for nutrient concentrations. The main nutrients of concern are total organic carbon, total nitrogen, and total phosphorous. We also were able to obtain concentrations of other essential minerals and nutrients. The pattern of sequestration currently is being determined from this project to show if the created marshes sequester carbon and other essential elements in a similar manner to the natural marshes. The analyses have been completed and results currently are being worked out. Preliminary results show differences between created and natural marshes. Statistical analyses are being performed to determine any definitive patterns and a manuscript is in the process of being written.
Future Activities:Project 1: Results from the 2-year project currently are going through a quality control and analysis.
Project 2: Data analyses are ongoing.
Project 3: The preliminary work for these experiments has been conducted, and the data will be collected during the next 6-8 months. We will collect R. maritima samples from different environments along the Gulf Coast and compare the genetic diversity using the ITRS regions mentioned above. In addition, we will begin to collect data to investigate the contribution of salinity and bottom substrate on the growth and proliferation of widgeongrass.
Project 4: Hematological and immunological data are still being collected and a full report of our results should be available in next year’s annual report.
Project 7: We will visit three sites (one natural and two restored marshes) and collect samples on three more dates.
Journal Articles: 4 Displayed | Download in RIS Format
| Other center views: | All 22 publications | 4 publications in selected types | All 4 journal articles |
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Edwards KR, Proffitt CE. Comparison of wetland structural characteristics between created and natural salt marshes in southwest Louisiana, USA. Wetlands 2003;23(2):344-356. |
R829584 (2004) |
not available |
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Edwards KR, Mills KP. Aboveground and belowground productivity of Spartina alterniflora (smooth cordgrass) in natural and created Louisiana salt marshes. Estuaries 2005;28(2):252-265 |
R829584 (2004) |
not available |
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Simpson CD, Paulsen M, Dills RL, Liu L-JS, Kalman DA. Determination of methoxyphenols in ambient atmospheric particulate matter: tracers for wood combustion. Environmental Science & Technology 2005;39(2):631-637. |
R829584 (2004) R827355 (2004) R827355 (Final) R827355C003 (2004) R827355C003 (Final) R827355C010 (2003) R827355C010 (Final) |
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Sneddon J, Hardaway C, Bobbadi KK, Beck JN. A study of a crude oil spill site for selected metal concentrations remediated by a controlled burning in southwest Louisiana. Microchemical Journal 2006;82(1):8-16. |
R829584 (2004) |
not available |
wetlands, wetland restoration, wetland remediation, marsh, Louisiana, restored marshes, sedimentation rate, vertical soil accretion, root zone influences,
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Ecosystem Protection/Environmental Exposure & Risk, Water, Scientific Discipline, Restoration, Aquatic Ecosystem Restoration, Ecological Risk Assessment, Ecology and Ecosystems, remediation, water quality, environmental rehabilitation, land use, ecological recovery, contaminated sediment, wetland restoration, coastal environments, oil spills
Relevant Websites:
Progress and Final Reports:
Original Abstract
Subprojects under this Center:
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R829584C001 Wetland Restoration and Remediation in Southwest Louisiana Marshes: A Study of Soil Elevation, Vertical Accretion, Shallow Subsidence and Root Zone Influences in Marshes Restored Using a Variety of Techniques
R829584C002 Developing Methods for Identifying Suitable Donors for Wetland Plant Restoration Through Transplantation
R829584C003 Effects of Salinity and Bottom Substrate Composition on the Growth and Proliferation of Widgeongrass (Ruppia maritima)
R829584C004 A Comparison of Health Parameters and Parasites in the Marsh Rice Rat Oryzomys palustris From Natural Freshwater, Saltwater, and Restored Marshes in the Sabine National Wildlife Refuge
R829584C005 Comparison of Metal Concentrations in Soils, Sediments, and Selected
Species From the Area Around Chevron Texaco No. 2 Bayou Tank Battery in
the Sabine National Wildlife Refuge in Southwest Louisiana and
Preliminary Determination of Oxidation State
R829584C006 Use of The Prairie Garden and Plant Material Center To Collect, Propagate, and Maintain Breeder Blocks and Garden Specimens of Louisiana Prairie And Wetland Ecotypes
R829584C007 Density of Marsh Periwinkles and Fire Ant Mounds in Natural and Restored Marshes in the Sabine National Wildlife Refuge