Effect of clonal reproduction on genetic structure in Pentaclethra macroloba (Fabaceae: Mimosoideae).

PubMed

Gaddis, Keith D; Zukin, Helen L; Dieterich, Inca A; Braker, Elizabeth; Sork, Victoria L

2014-06-01

The existence of monodominant forests on well-drained soils in tropical regions has been widely reported. Such forests most likely result from a combination of both ecological and evolutionary factors. Under conditions of high seed and seedling mortality, vegetative reproduction could create a reproductive advantage leading to forest dominance, and profoundly affect the distribution of genetic variation in a clonal species. We investigated these effects in a low diversity forest site in Northeastern Costa Rica dominated by the species Pentaclethra macroloba, which sprouts from the root mass of fallen trees and from snapped trunks. We examined the population structure of juvenile P. macroloba growing in different soil types and across an elevational gradient. Using seven molecular markers, we genotyped 173 juvenile P. macroloba from 18 plots (six plots in seasonally inundated swamps, and 12 plots in upland non-swamp) spanning 50-300m in elevation at La Selva Biological Station and the adjacent Reserva Ecológica Bijagual in Northeastern Costa Rica. We answered two specific questions: (1) How extensive is clonal reproduction? and (2) what is the distribution of genetic diversity and structure? We found that clonal reproduction occurred exclusively within inundated swamp areas. However, there was no significant difference between genetic diversity measures in swamp and non-swamp plots, which were both generally low when compared with other tropical forest species. Genetic structure was significant across all plots (F(ST) = -0.109). However, genetic structure among swamp plots (F(ST) = 0.128) was higher than among non-swamp upland plots (F(ST) = 0.093). Additionally, spatial autocorrelation among individuals within non-swamp upland plots was significant from the 25 to 100m spatial scale, but not within swamp plots. The degree of overall genetic structure we found in P. macroloba is high for a tropical forest tree. The incidence of clonal reproduction is a contributing factor in genetic differentiation, but the high structure among plots without clonal reproduction indicates that other factors contribute as well.

Changes in plant biomass and species composition of alpine Kobresia meadows along altitudinal gradient on the Qinghai-Tibetan Plateau.

PubMed

Wang, ChangTing; Cao, GuangMin; Wang, QiLan; Jing, ZengChun; Ding, LuMing; Long, RuiJun

2008-01-01

Alpine Kobresia meadows are major vegetation types on the Qinghai-Tibetan Plateau. There is growing concern over their relationships among biodiversity, productivity and environments. Despite the importance of species composition, species richness, the type of different growth forms, and plant biomass structure for Kobresia meadow ecosystems, few studies have been focused on the relationship between biomass and environmental gradient in the Kobresia meadow plant communities, particularly in relation to soil moisture and edaphic gradients. We measured the plant species composition, herbaceous litter, aboveground and belowground biomass in three Kobresia meadow plant communities in Haibei Alpine Meadow Ecosystem Research Station from 2001 to 2004. Community differences in plant species composition were reflected in biomass distribution. The total biomass showed a decrease from 13196.96+/-719.69 g/m(2) in the sedge-dominated K. tibetica swamp to 2869.58+/-147.52 g/m(2) in the forb and sedge dominated K. pygmaea meadow, and to 2153.08+/-141.95 g/m(2) in the forbs and grasses dominated K. humilis along with the increase of altitude. The vertical distribution of belowground biomass is distinct in the three meadow communities, and the belowground biomass at the depth of 0-10 cm in K. tibetica swamp meadow was significantly higher than that in K. humilis and K. pygmaea meadows (P<0.01). The herbaceous litter in K. tibetica swamp was significantly higher than those in K. pygnaeca and K. humilis meadows. The effects of plant litter are enhanced when ground water and soil moisture levels are raised. The relative importance of litter and vegetation may vary with soil water availability. In the K. tibetica swamp, total biomass was negatively correlated to species richness (P<0.05); aboveground biomass was positively correlated to soil organic matter, soil moisture, and plant cover (P<0.05); belowground biomass was positively correlated with soil moisture (P<0.05). However, in the K. pygnaeca and K. humilis meadow communities, aboveground biomass was positively correlated to soil organic matter and soil total nitrogen (P<0.05). This suggests that the distribution of biomass coincided with soil moisture and edaphic gradient in alpine meadows.

How does conversion from peat swamp forest to oil palm plantation affect emissions of nitrous oxide from the soil? A case study in Jambi, Indonesia

NASA Astrophysics Data System (ADS)

Hartill, Jodie; Hergoualc'h, Kristell; Comeau, Louis-Pierre; Jo, Smith; Lou, Verchot

2017-04-01

Half of the peatlands across Peninsular Malaysia, Borneo and Sumatra are 'managed'. Conversion of peat swamp forest to workable oil palm plantation requires a drastic, potentially irreversible, change to the landscape, to which fertilizers are then routinely applied. A combination of these factors is now widely thought to increase soil nitrous oxide (N2O) emissions, although there is high uncertainty due to gaps in the knowledge, both regionally and nationally. Despite the widespread use of fertilizers in plantations on peats, studies observing their effects remain very limited. Therefore, there is a need for in situ studies to evaluate how environmental parameters (edaphic properties, climate, soil moisture and N availability indicators) influence soil emissions. This 18 month study was located in plots local to each other, representing the start, intermediate and end of the land conversion process; namely mixed peat swamp forest, drained and logged forest and industrial oil palm plantation. Spatial variability was taken into account by differentiating the hollows and hummocks in the mixed peat swamp forest, and the fertilized zone and the zone without fertilizer addition in the oil palm plantation. Gas samples were collected each month from static chambers at the same time as key environmental parameters were measured. Intensive sampling was performed during a 35 day period following two fertilizer applications, in which urea was applied to palms at rates of 0.5 and 1 kg urea palm-1. Soil N2O emissions (kg N ha-1 y-1 ± SE) were low overall, but they were greater in the oil palm plantation (0.8 ± 0.1) than in the mixed peat swamp forest (0.3 ± 0.0) and the drained/logged forest (0.2 ± 0.0). In the mixed peat swamp forest, monthly average fluxes of N2O (g N ha-1 d-1 ± SE) were similar in the hollows (0.6 ± 0.2) and the hummocks (0.3 ± 0.1), whereas in the oil palm plantation they were consistently higher in the zone without fertilizer (2.5 ± 0.4) than in the fertilized zone (0.5 ± 0.1), even after fertilizer application. In the fertilized zones, the N2O fluxes following the two fertilizer applications were 2.4 and 4.5 times higher respectively than fluxes observed in the absence of fertilizers. No change in emissions was observed in the neighboring unfertilized zone at the time of fertilizer application. Soil N2O emissions were related to changes in air and soil temperature in the mixed peat swamp forest, air temperature and water table depth in the drained and logged forest, and rainfall on the day of measurement in the oil palm plantation. This research confirms that peat forest conversion to oil palm plantation has negative consequences on the emissions of N2O. It also corroborates an increase in emission due to fertilizer application, with a magnitude comparable to the emission factor provided by the IPCC guidelines, but this is restricted to the limited area of fertilizer application.

Ecology of red swamps in the glaciated northeast: a community profile

USGS Publications Warehouse

Golet, Francis C.; Calhoun, Aram J.K.; DeRagon, William R.

1993-01-01

This report is part of a series of profiles on the ecology of wetland and deepwater habitats. This particular profile addresses red maple swamps in the glaciated northeastern United States. Red maple (Acer rubrum) swamp is a dominant wetland type in most of the region; it reaches its greatest abundance in southern New England and northern New Jersey, where it comprises 60-800/o of all inland wetlands. Red maple swamps occur in a wide variety of hydrogeologic settings, from small, isolated basins in till or glaciofluvial deposits to extensive wetland complexes on glacial lake beds, and from hillside seeps to stream floodplains and lake edges. Individual swamps may be seasonally flooded, temporarily flooded, or seasonally saturated, and soils may be mineral or organic. As many as five distinct vegetation layers may occur in these swamps, including trees, saplings, shrubs, herbs, and ground cover plants such as bryophytes and clubmosses. On a regional scale, red maple swamps support at least 50 species of trees, more than 90 species of shrubs and vines, and more than 300 species of nonwoody plants. These swamps also provide habitat for a rich faunal community, including several wetland-dependent species. In areas that are becoming urbanized, these wetlands often constitute critical habitat for facultative species as well. Red maple swamps also are important sites for flood storage, water quality improvement, recreation, scenic beauty, and open space.

Connecting carbon and nitrogen storage in rural wetland soil to groundwater abstraction for urban water supply.

PubMed

Lewis, David Bruce; Feit, Sharon J

2015-04-01

We investigated whether groundwater abstraction for urban water supply diminishes the storage of carbon (C), nitrogen (N), and organic matter in the soil of rural wetlands. Wetland soil organic matter (SOM) benefits air and water quality by sequestering large masses of C and N. Yet, the accumulation of wetland SOM depends on soil inundation, so we hypothesized that groundwater abstraction would diminish stocks of SOM, C, and N in wetland soils. Predictions of this hypothesis were tested in two types of subtropical, depressional-basin wetland: forested swamps and herbaceous-vegetation marshes. In west-central Florida, >650 ML groundwater day(-1) are abstracted for use primarily in the Tampa Bay metropolis. At higher abstraction volumes, water tables were lower and wetlands had shorter hydroperiods (less time inundated). In turn, wetlands with shorter hydroperiods had 50-60% less SOM, C, and N per kg soil. In swamps, SOM loss caused soil bulk density to double, so areal soil C and N storage per m(2) through 30.5 cm depth was diminished by 25-30% in short-hydroperiod swamps. In herbaceous-vegetation marshes, short hydroperiods caused a sharper decline in N than in C. Soil organic matter, C, and N pools were not correlated with soil texture or with wetland draining-reflooding frequency. Many years of shortened hydroperiod were probably required to diminish soil organic matter, C, and N pools by the magnitudes we observed. This diminution might have occurred decades ago, but could be maintained contemporarily by the failure each year of chronically drained soils to retain new organic matter inputs. In sum, our study attributes the contraction of hydroperiod and loss of soil organic matter, C, and N from rural wetlands to groundwater abstraction performed largely for urban water supply, revealing teleconnections between rural ecosystem change and urban resource demand. © 2014 John Wiley & Sons Ltd.

Quantifying the impacts of land use change on soil organic carbon losses in tropical peatlands

NASA Astrophysics Data System (ADS)

Farmer, J.; Smith, J.; Smith, P.; Matthews, R.

2012-04-01

The challenge of collecting field measurements of soil carbon dioxide (CO2) efflux and soil carbon (C) in tropical peatlands creates an opportunity for the use of SOC models for predicting local and regional impacts of land use and climate change on these soils, offering a way of translating this limited data into tangible results. Previously, no soil C model existed for use in non-steady state sites such as those found on tropical peats- in particular peat swamp forests which accumulate C, and oil palm plantations which are grown for 20-25 years between re-plantings. A simple, user friendly model has been created for use by scientists, policy makers and plantation managers. This model uses only limited inputs to predict the changes to soil C from land use and climate change. The model runs on the assumption that plant inputs can be related to yield, and that this can be used to derive the decomposition of SOM. It uses a simple decomposition response to determine the changes to the soil C. The model can run in a basic form if data is very limited, or a more complex form with modifiers for temperature, pH, salinity and soil moisture if this data is available. Using measured CO2 efflux and soil C values from peat cores, combined with literature values, we demonstrate the efficacy of the model, showing how we have identified and addressed some of the issues related to modelling soil C losses from tropical peat soils under land use change. Key challenges addressed included quantifying the effects of drainage when peat swamp forests are converted to oil palm plantations, and comparing field results between sites because in oil palm plantations the original soil conditions prior to conversion from peat swamp forest were largely unknown.

Evaluation of six herbicides for control of swamp smartweed [Persicaria hydropiperoides (Michx.) Small] under flooded and moist soil conditions

USDA-ARS?s Scientific Manuscript database

Six herbicides (2,4-D, diquat, glyphosate, imazamox, imazapyr, and triclopyr) were tested for efficacy on swamp smartweed (Polygonum hydropiperoides Michx.) in two studies in Mississippi. In the first study in a pond, glyphosate (2.1 and 4.2 kg ai ha-1), imazapyr (0.3 and 0.5 kg ai ha-1), and tricl...

Presettlement Forests of the Black Swamp Area, Cache River,Woodruff County, Arkansas, from Notes of the First Land Survey

Treesearch

Thomas L. Foti

2001-01-01

Relationships between forest vegetation and soil were reconstructed from field notes of the 1846 Public Land Survey (PLS) along a portion of the Cache River including Black Swamp. Locations of corners were digitized long with species,diameter,and distance from section or quarter-section corners. Trees were grouped for analysis according to occurrence on groups of...

Silvical characteristics of red maple (Acer rubrum)

Treesearch

Russell J. Hutnik; Harry W. Yawney

1961-01-01

Red maple (Acer rubrum L.) is also known as Carolina red maple, scarlet maple, soft maple, swamp maple, water maple, and white maple. Taxonomists recognize several varieties of red maple. The most common is Drummond red maple (Acer rubrum var. drummondii (Hook, & Arn.) Sarg.).

[Preliminary plant inventory of the palm-swamps in the Caribbean of Costa Rica and Nicaragua].

PubMed

Rueda, Ricardo; Jarquín, Orlando; Munguía, Blanca; Reyes, Aquiles; Coronado, Indiana

2013-09-01

In the Caribbean slope of Isthmian Central America, plant associations dominated by the palms Raphia taedigera and Manicaria saccifera develop in poorly drained or waterlogged soils. These associations are known locally as yolillales or palm-swamps, although there are differences in the forest structure and plant diversity associated with both palm species. In this paper, we report the results of a preliminary inventory of tree species found in eight palm-swamps at five locations in southeastern Nicaragua and northeastern Costa Rica. Our data reveal low tree diversity in these swamps with only 60 species accounted in them. This figure is equivalent to close to 8% of the plant species known for this region. In general, R. taedigera dominates flooded areas with extensive hydroperiods and lower floristic diversity, while M. saccifera is often found in flooded forests with more structure and diversity.

Transformation of peat horizon in swampy southern taiga forests under the impact of surface drainage

NASA Astrophysics Data System (ADS)

Vomperskii, S. E.; Vomperskaya, M. I.; Glukhova, T. V.; Valyaeva, N. A.

2017-10-01

The results of stationary studies of swampy southern taiga forests in Yaroslavl oblast are presented. Estimates of changes in the thickness of peat horizon in peat podzolic gley soils (Folic Albeluvisols) of forests subjected to clearcutting and further intensive forest management in the past 30 years are given. The mean annual precipitation in these three decades has been 116 mm higher than that during the preceding three decades, which has led to a progressive swamping of spruce stands on heavy loamy soils within virtually flat (with slopes up to 0.0035) surfaces and an increase in the organic matter storage in the peat soil horizon with the mean annual rate of 22-68 g/m2. On more pronounced slopes (0.0050), no swamping of spruce and pine stands growing on sandy soils has taken place. Surface drainage of swampy forests through the network of shallow ditches has led to an increase in the productivity of forests; in most cases, the pool of organic matter in the peat horizon has been decreasing with the mean annual rate of 32-46 g/m2. This attests to the reversible character of swamping in dependence on climatic fluctuations and forestry measures. Changes in the carbon pool of swampy soils during short (several years) excessively wet or excessively dry periods may be significantly higher than the average values for 30 years in different types of forests. This allows us to consider swampy forests as the source of significant errors in the estimates of the current contribution of biota to the carbon cycle, because their role (as well as the role of other forests) is assessed without taking into account considerable short-term fluctuations in the carbon pool of their soils.

HTO and OBT concentrations in a wetland ecosystem

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

Kim, S. B.; Workman, W. J. G.; Davis, P. A.

2008-07-15

Tritiated water (HTO) and organically bound tritium (OBT) concentrations in the non-human biota inhabiting Duke Swamp were measured during the 2005 growing season. Samples of surface water, soil, plants, precipitation, wild animals and air moisture were collected from 2005 May to October at five locations in the swamp and analyzed for their tritium content. HTO concentrations in air moisture decreased with height since the tritium source is in the ground. Soil HTO concentrations were not closely related to the concentrations in nearby surface water and the HTO concentration in balsam fir needles showed no clear pattern with height. HTO concentrationsmore » in moss, grass and alder leaves decreased in September, which is the time when metabolic activity is reduced. OBT concentrations in a given compartment showed less variation than the HTO concentrations in that compartment. The OBT/HTO ratio was approximately one for soil and less than one for plants, with the exception of lichen. The OBT/HTO ratio in most wild animals was also less than one, but increased to more than 2.0 for mice. Although the tritium concentrations varied substantially in space and time in Duke Swamp, the fact that OBT/HTO <1 for most compartments suggests that equilibrium conditions hold locally. (authors)« less

A tropical freshwater wetlands: I. Structure, growth, and regeneration

USGS Publications Warehouse

Allen, J.A.; Krauss, K.W.; Ewel, K.C.; Keeland, B.D.; Waguk, E.E.

2005-01-01

Forested wetlands dominated by Terminalia carolinensis are endemic to Micronesia but common only on the island of Kosrae, Federated States of Micronesia. On Kosrae, these forests occur on Nansepsep, Inkosr, and Sonahnpil soil types, which differ in degree of flooding and soil saturation. We compared forest structure, growth, nutrition, and regeneration on two sites each on Nansepsep and Inkosr soils and one site on the much less common Sonahnpil soil type. Terminalia tree sizes were similar on all three soil types, but forests differed in total basal area, species of smaller trees, and total plant species diversity. Terminalia regeneration was found only on the Inkosr soil type, which had the highest water table levels. Other Terminalia species are relatively light demanding, and T. carolinensis exhibited similar characteristics. It is therefore likely that Terminalia requires periodic, but perhaps naturally rare, stand-replacing disturbances (e.g., typhoons) in order to maintain its dominanace, except on the wettest sites, where competition from other species is reduced. Terminalia swamps in the Nansepsep soil type appeared to be at the greatest risk of conversion to other uses, but swamps on all three types may face reater pressure as Kosrae's population increases and the island's infrastrucure becomes more developed.

Tropical organic soils ecosystems in relation to regional water resources in southeast Asia

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

Armentano, T. V.

1982-01-01

Tropical organic soils have functioned as natural sinks for carbon, nitrogen, slfur and other nutrients for the past 4000 years or more. Topographic evolution in peat swamp forests towards greater oligotrophy has concentrated storage of the limited nutrient stock in surface soils and biota. Tropical peat systems thus share common ecosystem characteristics with northern peat bogs and certain tropical oligotrophic forests. Organic matter accumulation and high cation-exchange-capacity limit nutrient exports from undisturbed organic soils, although nutrient retention declines with increasing eutrophy and wetland productivity. Peat swamps are subject to irreversible degradation if severely altered because disturbance of vegetation, surface peatsmore » and detritus can disrupt nuttrient cycles and reduce forest recovery capacity. Drainage also greatly increases exports of nitrogen, phosphorus and other nutrients and leads to downstream eutrophication and water quality degradation. Regional planning for clean water supplies must recognize the benefits provided by natural peatlands in balancing water supplies and regulating water chemistry.« less

39 CFR 776.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... buildings, structures and improvements. Contending site means a site or existing building for a proposed... saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas. ...

Effects of irrigation on seed production and vegetative characteristics of four moist-soil plants on impounded wetlands in California

USGS Publications Warehouse

Mushet, D.M.; Euliss, N.H.; Harris, S.W.

1992-01-01

We examined the effects of irrigation on 4 moist-soil plants commonly managed for waterfowl in the Sacramento Valley, California. Irrigation resulted in taller and heavier swamp timothy (Heleochloa schoenoides), pricklegrass (Crypsis niliaca), and sprangletop (Leptochloa fasicularis). Barnyardgrass (Echinochloa crusgalli) grew taller in irrigated wetlands, but no significant difference in weight was detected. Only sprangletop yielded larger seed masses in response to irrigation. Without irrigation, swamp timothy and pricklegrass assumed a typical prostrate growth form, but with irrigation, they assumed a vertical growth form. Irrigation did not significantly affect plant density. Because of rising water costs, wetland managers should consider wildlife management objectives and plant responses before implementing irrigation practices.

Use of oil shale ash in road construction: results of follow-up environmental monitoring.

PubMed

Reinik, Janek; Irha, Natalya; Koroljova, Arina; Meriste, Tõnis

2018-01-05

Oil shale ash (OSA) was used for road construction in a pristine swamp area in East-Estonia during 2013-2014. OSA was used as a binder both in mass stabilization of soft peat soil and in the upper layer. Use of OSA in civil engineering always raises questions about the environmental safety of such activities. Post-construction environmental monitoring of the pilot section was carried out in 2014 and 2015. The monitoring program involved surface water and soil sampling campaigns. Samples were analyzed for selected constituents and parameters of environmental concern. The paper gives data for assessing the environmental impact and evaluation of potential risks associated with construction of roads using OSA. Leaching of hazardous compounds from the pilot section to surrounding aqueous environment was not observed during the monitoring program. Still, the road construction affected the concentration of sulfates in surrounding surface water. Also, the water-soluble content of barium in surface water correlated significantly with the concentrations of chloride and sulfate ion and electric conductivity of the surface water. Therefore, it is recommended to monitor the electric conductivity, concentrations of sulfates, chlorides, and barium in nearby surface water when OSA is used in road construction.

Forest Types in the Lower Suwannee River Floodplain, Florida?-A Report and Interactive Map

USGS Publications Warehouse

Darst, M.R.; Light, H.M.; Lewis, L.J.; Sepulveda, A.A.

2003-01-01

A map of forest types in the lower Suwannee River floodplain, Florida, was created during a study conducted from 1996 to 2000 by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District. The map is presented with this report on a compact disc with interactive viewing software. The forest map can be used by scientists for ecological studies in the floodplain based on land cover types and by landowners and management personnel making land use decisions. The study area is the 10-year floodplain of the lower Suwannee River from its confluence with the Santa Fe River to the lower limit of forests near the Gulf of Mexico. The floodplain is divided into three reaches: riverine (non-tidal), upper tidal, and lower tidal, due to changes in hydrology, vegetation, and soils with proximity to the coast. The 10-year floodplain covers about 21,170 hectares; nearly 88 percent of this area (18,580 hectares) is mapped as 14 major forest types. Approximately 29 percent (5,319 hectares) of these forests have been altered by agriculture or development. About 75 percent of the area of major forest types (13,994 hectares) is wetland forests and about 25 percent (4,586 hectares) is upland forests. Tidal wetland forests (8,955 hectares) cover a much greater area than riverine wetland forests (5,039 hectares). Oak/pine upland forests are present in the riverine and upper tidal reaches of the floodplain on elevations that are inundated only briefly during the highest floods. High bottomland hardwoods are present on the higher levees, ridges, and flats of the riverine reach where soils are usually sandy. Low bottomland hardwood forests are present in the riverine reach on swamp margins and low levees and flats that are flooded continuously for several weeks or longer every 1 to 3 years. Riverine swamps are present in the lowest and wettest areas of the non-tidal floodplain that are either inundated or saturated most of the time. Upper tidal bottomland hardwood forests are present on sandy soils on high flats and in transitional areas between upland forests and swamps. Upper tidal mixed forests are found on low levees or between swamps and higher forest types. Upper tidal swamps are present at elevations below median monthly high stage and usually have surface soils that are permanently saturated mucks. Lower tidal hammocks are found on higher elevations that do not receive regular tidal inundation but have a high water table and are briefly inundated by storm surges several times a decade. Lower tidal mixed forests include swamps with numerous small hummocks or less common larger hummocks. Lower tidal swamps are found on deep muck soils that are below the elevation of the median daily or monthly high stage. Seven additional land cover types (2,590 hectares) are mapped. Water in the main channel of the lower Suwannee River (1,767 hectares) was mapped separately from open water in the floodplain (239 hectares). Other land cover types are: seepage slopes (70 hectares), isolated forested wetlands (19 hectares), marshes upstream of the tree line (505 hectares), beds of emergent aquatic vegetation (21 hectares), and floodplain glades (46 hectares)

40 CFR 503.9 - General definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... site. (t) Pollutant is an organic substance, an inorganic substance, a combination of organic and... typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs...

40 CFR 503.9 - General definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... site. (t) Pollutant is an organic substance, an inorganic substance, a combination of organic and... typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs...

40 CFR 503.9 - General definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... site. (t) Pollutant is an organic substance, an inorganic substance, a combination of organic and... typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs...

40 CFR 503.9 - General definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... site. (t) Pollutant is an organic substance, an inorganic substance, a combination of organic and... typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs...

Soil properties and growth of swamp white oak and pin oak on bedded soils in the lower Missouri River floodplain

Treesearch

John M. Kabrick; Daniel C. Dey; J. W. Van Sambeek; Michael Wallendorf; Michael A. Gold

2005-01-01

Restoring bottomland hardwood ecosystems is of great interest along the lower Missouri River and within the Mississippi Alluvial Valley. However, bottomland hardwood plantings commonly have a high failure rate. Among reasons cited for failures are frequent flooding and poorly drained site conditions. Soil bedding is a commonly used site preparation method shown to...

Performance measures for a Mississippi River reintroduction into the forested wetlands of Maurepas Swamp

USGS Publications Warehouse

Krauss, Ken W.; Shaffer, Gary P.; Keim, Richard F.; Chambers, Jim L.; Wood, William B.; Hartley, Stephen B.

2017-06-09

The use of freshwater diversions (river reintroductions) from the Mississippi River as a restoration tool to rehabilitate Louisiana coastal wetlands has been promoted widely since the first such diversion at Caernarvon became operational in the early 1990s. To date, aside from the Bonnet Carré Spillway (which is designed and operated for flood control), there are only four operational Mississippi River freshwater diversions (two gated structures and two siphons) in coastal Louisiana, and they all target salinity intrusion, shellfish management, and (or) the enhancement of the integrity of marsh habitat. River reintroductions carry small sediment loads for various design reasons, but they can be effective in delivering fresh­water to combat saltwater intrusion and increase the delivery of nutrients and suspended fine-grained sediments to receiving wetlands. River reintroductions may be an ideal restoration tool for targeting coastal swamp forest habitat; much of the area of swamp forest habitat in coastal Louisiana is undergo­ing saltwater intrusion, high rates of submergence, and lack of riverine flow leading to reduced concentrations of important nutrients and suspended sediments, which sustain growth and regeneration, help to aerate swamp soils, and remove toxic compounds from the rhizosphere.The State of Louisiana Coastal Protection and Restora­tion Authority (CPRA) has made it a priority to establish a small freshwater river diversion into a coastal swamp forest located between Baton Rouge and New Orleans, Louisiana, to reintroduce Mississippi River water to Maurepas Swamp. While a full understanding of how a coastal swamp forest will respond to new freshwater loading through a Mississippi River reintroduction is unknown, this report provides guidance based on the available literature for establishing performance measures that can be used for evaluating the effectiveness of a Mississippi River reintroduction into the forested wetlands of Maurepas Swamp (project PO-29 of the Coastal Wetlands Planning, Protection and Restoration Act) and aid in adaptive management of the project. PO-29 is a small river reintroduction in scope, and through its operation, it will provide information about the feasibility and reasonable expectations for future river reintroduction projects targeting coastal swamp forests in Louisiana.Located near Garyville, Louisiana, the Mississippi River reintroduction into Maurepas Swamp project is being designed to deliver a maximum flow of 57 cubic meters per second (m3/s) (or about 2,000 cubic feet per second [ft3/s]) directly from the river, but with a maximum flow through the outflow channel of 42 m3/s (or 1,500 ft3/s) available for at least half of the year. The river reintroduction will divert Mississippi River water through channelized flow and surface water to impact approximately 16,583 hectares (ha) of wetland habitat, much of which is swamp forest and swamp forest transitioning into marsh habitat. The Mississippi River reintroduction into Maurepas Swamp and associated outfall management features collectively should facilitate connectivity of water between the Mississippi River and the entire project area.At any given location, hydrologic connectivity should occur at intervals between twice yearly and once per decade, and hydrologic management must allow the potential for water drawdowns to foster tree regeneration every 3–13 years. The river reintroduction is also anticipated to maintain salinity in swamp forests dominated by Taxodium distichum (baldcypress) to less than 1.3 practical salinity units (psu) and maintain salinity in mixed baldcypress and Nyssa aquatica (water tupelo) swamp forests to less than 0.8 psu. The river reintroduction should promote soil surface elevation gains of 8–9 millimeters per year (mm/yr) (range, 4.9–12.1 mm/yr) to offset relative sea-level rise and keep total river water nitrate (NO3-) loading into Maurepas Swamp to about 11.25 grams (g) of nitrogen (N) per square meter per year (m-2 yr-1 ) (range, 7.1–15.4 g N m-2 yr-1) to promote near complete uptake of NO3- by the vegetation in the receiving wetlands and reduce impacts to water quality in adjacent and connected water ways (for example, Blind River) and Lake Maurepas. With these performance measures maintained over time, we further expect swamp forest stands to realize improvements in stand density index of as much as 30–45 percent of maximum values for the stand type while maintaining an overstory leaf area index of 2.0–2.9 square meters per square meter or higher as swamp forests recover from decades of low flow, saltwater intrusion, reduced nutrients, and surface elevation deficits associated with isolation from the Mississippi River.Associated with these performance measures are two major uncertainties: (1) an assumption that we can rely on existing data, literature, and modeling from coastal swamp forests to establish these performance measures and (2) an unknown time frame for evaluating these performance mea­sures. Some performance measures can be assessed quickly, such as those associated with hydrology and nutrient uptake. Some performance measures, such as changes in soil surface elevation and forest structural integrity, could take longer to assess. Once performance measures are assessed across dif­ferent time scales, however, adjustments to operations of the Mississippi River reintroduction into Maurepas Swamp can be swift. The proposed performance measures are ideal targets, mostly without specific consideration of practical, operational constraints. The measures are intended to be the basis by which adaptive management of the diversion structures can be evaluated. The measures are defined without regard to current conditions so that project success can be evaluated on net outcomes rather than specific change from existing condi­tions. We expect that the Mississippi River reintroduction into Maurepas Swamp will slow degradation and extend the life of the swamp for decades to centuries.

Stocks and fluxes of carbon associated with land use change in Southeast Asian tropical peatlands: A review

NASA Astrophysics Data System (ADS)

Hergoualc'h, Kristell; Verchot, Louis V.

2011-06-01

The increasing and alarming trend of degradation and deforestation of tropical peat swamp forests may contribute greatly to climate change. Estimates of carbon (C) losses associated with land use change in tropical peatlands are needed. To assess these losses we examined C stocks and peat C fluxes in virgin peat swamp forests and tropical peatlands affected by six common types of land use. Phytomass C loss from the conversion of virgin peat swamp forest to logged forest, fire-damaged forest, mixed croplands and shrublands, rice field, oil palm plantation, and Acacia plantation were calculated using the stock difference method and estimated at 116.9 ± 39.8, 151.6 ± 36.0, 204.1 ± 28.6, 214.9 ± 28.4, 188.1 ± 29.8, and 191.7 ± 28.5 Mg C ha-1, respectively. Total C loss from uncontrolled fires ranged from 289.5 ± 68.1 Mg C ha-1 in rice fields to 436.2 ± 77.0 Mg C ha-1 in virgin peat swamp forest. We assessed the effects of land use change on C stocks in the peat by looking at how the change in vegetation cover altered the main C inputs (litterfall and root mortality) and outputs (heterotrophic respiration, CH4 flux, fires, and soluble and physical removal) before and after conversion. The difference between the soil input-output balances in the virgin peat swamp forest and in the oil palm plantation gave an estimate of peat C loss of 10.8 ± 3.5 Mg C ha-1 yr-1. Peat C loss from other land use conversions could not be assessed due to lack of data, principally on soil heterotrophic respiration rates. Over 25 years, the conversion of tropical virgin peat swamp forest into oil palm plantation represents a total C loss from both biomass and peat of 427.2 ± 90.7 Mg C ha-1 or 17.1 ± 3.6 Mg C ha-1 yr-1. In all situations, peat C loss contributed more than 63% to total C loss, demonstrating the urgent need in terms of the atmospheric greenhouse gas burden to protect tropical virgin peat swamp forests from land use change and fires.

Characterising Wetland Properties in Relation to the Abundance of an Invasive Species

NASA Astrophysics Data System (ADS)

Yanosik, L. E.; McEnroe, N. A.

2008-12-01

Purple loosestrife (Lythrum salicaria) is a colorful but aggressive invasive species found at the Goodyear Swamp Sanctuary in Upstate New York. Flowering from June to September allows a large number of seeds to spread quickly throughout the growing season. This invasive species can alter can alter a wetland's functional properties by impacting the hydrology and soil properties. These modified properties are of concern to wetland scientists and wetland managers as the characterisation of wetland condition becomes more important. Control or eradication of purple loosestrife within the Goodyear Swamp has become regionally important and is carried out by a U.S. Department of Agriculture approved leaf-eating beetle Galerucella calmariensis. A study to investigate the environmental conditions in which purple loosestrife has propagated and changed the native flora of Goodyear Swamp was developed. The aim was to characterize the soil physiochemical properties and hydrological conditions under which the species occurs. These data are relevant to be able to highlight the wetland conditions under which purple loosestrife might invade and to be able to compare treated and untreated wetlands. We highlight key differences in wetland functional properties caused by the invasion of this species.

Effects of warming and nitrogen fertilization on GHG flux in an alpine swamp meadow of a permafrost region.

PubMed

Chen, Xiaopeng; Wang, Genxu; Zhang, Tao; Mao, Tianxu; Wei, Da; Song, Chunlin; Hu, Zhaoyong; Huang, Kewei

2017-12-01

Uncertainties in the seasonal changes of greenhouse gases (GHG) fluxes in wetlands limit our accurate understanding of the responses of permafrost ecosystems to future warming and increased nitrogen (N) deposition. Therefore, in an alpine swamp meadow in the hinterland of the Qinghai-Tibet Plateau, a simulated warming with N fertilization experiment was conducted to investigate the key GHG fluxes (ecosystem respiration [Re], CH 4 and N 2 O) in the early (EG), mid (MG) and late (LG) growing seasons. Results showed that warming (6.2 °C) increased the average seasonal Re by 30.9% and transformed the alpine swamp meadow from a N 2 O sink to a source, whereas CH 4 flux was not significantly affected. N fertilization (4 g N m -2 a -1 ) alone had no significant effect on the fluxes of GHGs. The interaction of warming and N fertilization increased CH 4 uptake by 69.6% and N 2 O emissions by 26.2% compared with warming, whereas the Re was not significantly affected. During the EG, although the soil temperature sensitivity of the Re was the highest, the effect of warming on the Re was the weakest. The primary driving factor for Re was soil surface temperature, whereas soil moisture controlled CH 4 flux, and the N 2 O flux was primarily affected by rain events. The results indicated: (i) increasing N deposition has both positive and negative feedbacks on GHG fluxes in response to climate warming; (ii) during soil thawing process at active layer, low temperature of deep frozen soils have a negative contribution to Re in alpine ecosystems; and (iii) although these alpine wetland ecosystems are buffers against increased temperature, their feedbacks on climate change cannot be ignored because of the large soil organic carbon pool and high temperature sensitivity of the Re. Copyright © 2017 Elsevier B.V. All rights reserved.

Carbon Dioxide and Methane Flux Related to Forest Type and Managed and Unmanaged Conditions in the Great Dismal Swamp, USA

NASA Astrophysics Data System (ADS)

Gutenberg, L. W.; Krauss, K.; Qu, J. J.; Hogan, D. M.; Zhu, Z.; Xu, C.

2017-12-01

The Great Dismal Swamp in Virginia and North Carolina, USA, has been greatly impacted by human use and management for the last few hundred years through logging, ditching, and draining. Today, the once dominant cedar, cypress and pocosin forest types are fragmented due to logging and environmental change. Maple-gum forest has taken over more than half the remaining area of the swamp ecosystem, which is now a National Wildlife Refuge and State Park. The peat soils and biomass store a vast quantity of carbon compared with the size of the refuge, but this store is threatened by fire and drying. This study looks at three of the main forest types in the GDS— maple-sweet gum, tall pine pocosin, and Atlantic white cedar— in terms of their carbon dioxide and methane soil flux. Using static chambers to sample soil gas flux in locally representative sites, we found that cedar sites showed a higher carbon dioxide flux rate as the soil temperature increased than maple sites, and the rate of carbon dioxide flux decreased as soil moisture increased faster in cedar sites than in maple sites. Methane flux increased as temperature increased for pocosin, but decreased with temperature for cedar and maple. All of the methane fluxes increased as soil moisture increased. Cedar average carbon dioxide flux was statistically significantly different from both maple and pocosin. These results show that soil carbon gas flux depends on soil moisture and temperature, which are factors that are changing due to human actions, as well as on forest type, which is also the result of human activity. Some of these variables may be adjustable by the managers of the land. Variables other than forest type, temperature and soil moisture/inundation may also play a role in influencing soil flux, such as stand age, tree height, composition of the peat and nutrient availability, and source of moisture as some sites are more influenced by groundwater from ditches and some more by rainfall depending on the direction of groundwater lateral flow. Increasing temperatures and changes in precipitation and soil moisture may impact the carbon storage and health of this ecosystem, although it is already strongly influenced by anthropogenic activities such as past logging and water level management.

Do site-specific radiocarbon measurements reflect localized distributions of 14C in biota inhabiting a wetland with point contamination sources?

PubMed

Yankovich, T; King-Sharp, K J; Benz, M L; Carr, J; Killey, R W D; Beresford, N A; Wood, M D

2013-12-01

Duke Swamp is a wetland ecosystem that receives (14)C via a groundwater pathway originating from a waste management area on Atomic Energy Canada Limited's Chalk River Laboratories site. This groundwater reaches the surface of the swamp, resulting in relatively high (14)C levels over an area of 146 m(2). The objective of this study was to quantify (14)C concentrations in flora and fauna inhabiting areas of Duke Swamp over the gradient of (14)C activity concentrations in moss to determine whether (14)C specific activities in receptor biota reflect the localized nature of the groundwater source in the swamp. Representative receptor plants and animals, and corresponding air and soil samples were collected at six sites in Duke Swamp with (14)C specific activities in air that ranged from 1140 to 45,900 Bq/kg C. In general, it was found that specific activities of (14)C in biota tissues reflected those measured in environmental media collected from the same sampling site. The findings demonstrate that mosses could be used in monitoring programs to ensure protection of biota in areas with elevated (14)C, negating the need to capture and euthanize higher organisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Geochemistry of mercury in tropical swamps impacted by gold mining.

PubMed

Marrugo-Negrete, José; Pinedo-Hernández, José; Díez, Sergi

2015-09-01

Artisanal and small-scale gold mining (ASGM) poses a serious threat to the local environment. Colombia has very active ASGM activities, where mercury (Hg) ends in piles of mining waste, soils, and waterways. In this study, we assessed Hg speciation and bioavailability in sediments of two tropical swamps, impacted by ASGM. In Ayapel swamp, total Hg (T-Hg) concentrations in sediments ranged between 145 and 313 ng g(-1) dry weight (dw) (mean: 235 ± 49 ng g(-1) dw), whereas Grande Achi swamp levels are 3-fold higher (range: 543-1021 ng g(-1) dw; mean: 722 ± 145 ng g(-1) dw). Even though lower levels of Hg were found in Ayapel, methylation was found to be significantly higher than in Grande Achi, and it is significantly higher in the dry than in the rainy season for both swamps. This increased methylation is linked to the statistically significant correlation between T-Hg, MeHg and organic matter in the Ayapel swamp. In fact, Hg content in both swamps is mainly associated to the organic fraction (Hg-o), with a higher statistically significant difference in Ayapel (43 ± 5%) compared to Grande Achi (33 ± 5%). On the other hand, a significant percentage (30 ± 6%) of elemental Hg fraction (Hg-e) was found in Grande Achi, directly related with Hg released during the gold recovery process from upstream ASGM sites. The percentage of the bioavailable fraction (Hg-w and Hg-h) is elevated (up to 15%), indicating a potential risk to the aquatic environment and human health because these labile Hg species could enter the water column and bioaccumulate in biota. Copyright © 2015 Elsevier Ltd. All rights reserved.

Research on the Integration of Bionic Geometry Modeling and Simulation of Robot Foot Based on Characteristic Curve

NASA Astrophysics Data System (ADS)

He, G.; Zhu, H.; Xu, J.; Gao, K.; Zhu, D.

2017-09-01

The bionic research of shape is an important aspect of the research on bionic robot, and its implementation cannot be separated from the shape modeling and numerical simulation of the bionic object, which is tedious and time-consuming. In order to improve the efficiency of shape bionic design, the feet of animals living in soft soil and swamp environment are taken as bionic objects, and characteristic skeleton curve, section curve, joint rotation variable, position and other parameters are used to describe the shape and position information of bionic object’s sole, toes and flipper. The geometry modeling of the bionic object is established by using the parameterization of characteristic curves and variables. Based on this, the integration framework of parametric modeling and finite element modeling, dynamic analysis and post-processing of sinking process in soil is proposed in this paper. The examples of bionic ostrich foot and bionic duck foot are also given. The parametric modeling and integration technique can achieve rapid improved design based on bionic object, and it can also greatly improve the efficiency and quality of robot foot bionic design, and has important practical significance to improve the level of bionic design of robot foot’s shape and structure.

Effects of soil cadmium on growth of bald cypress seedlings under flooded and non-flooded conditions

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

Fredenberg, S.C.; Neufeld, H.S.

1995-06-01

Cypress swamps are occasionally used for tertiary waste water treatment. The sewage input to these ecosystems often contains high amounts of cadmium. To date, there have been no studies of the potential effects of cadmium on the growth of the dominant trees in these swamps, the bald cypress (Taxodium distichum (L.) Rich. var. distichum). Seedlings were grown for 16 weeks in organic soils amended with 0, 40, 80, and 120 ppm Cd (mg Cd/Kg soil dry weight) under both flooded and non-flooded conditions. Near the end of the growth period, leaf gas exchange was measured using a Li-Cor portable system.more » At the conclusion of the experiment, seedlings were harvested and separated into leaves, stems, branches and roots and dried at 65 C. Cadmium had no significant effects on any measured parameter. Flooding did Increase stem diameter, while decreasing height and biomass, but it had no effect on tolerance to Cd. Flooding reduced total biomass by 35%, mainly due to greatly reduced root growth (66% reduction). Cypress trees were probably protected from the toxic effects of Cd by the binding of this heavy metal to organic compounds in the soil.« less

The ecology of hydric hammocks: A community profile

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

Vince, S.W.; Humphrey, S.R.; Simons, R.W.

1989-09-01

This publication describes the nature and dynamics of a type of forested wetland called hydric hammock. Hydric hammock has not been carefully defined or studied, and it often is ignored or lumped with other mixed hardwood forests. Hydric hammock occurs at low elevations along the gulf coast of Florida from Aripeka to St. Marks and at various inland sites in Florida. The largest contiguous tracts occur along the gulf coast and the St. Johns River. Sites typically are gentle slopes between mesic hammock or pine flatwoods and river swamp, wet prairie, or marsh. Hydric hammocks occur on soils that aremore » poorly drained or have high water tables, and occasional flooding saturates the soils long enough to restrict or modify species composition. Hydric hammocks typically contain live and swamp laurel oaks ({ital Quercus virginiana} and {ital Quercus laurifolia}), cabbage palm ({ital Sabal palmetto}), southern red-cedar ({ital Juniperus silicicola}), sweetgum ({ital Liquidambar styraciflua}), and hornbeam ({ital Carpinus caroliniana}). Hydric hammocks lack certain tree species while sharing others with both upslope mesic forests and downslope swamp forests. The vertebrate fauna contains no unique species but has a high diversity of species and high abundance of selected species. Hydric hammocks are particularly important habitat for game species and for overwintering passerine birds. 148 refs., 40 figs., 12 tabs.« less

Brazil: Rio Branco

Atmospheric Science Data Center

2013-04-18

... is a center for the distribution of goods, including rubber, metals, medicinal plants, Brazil nuts and timber. Colonization projects in the ... terrain is of a poorly-draining clay hardpan soil, and heavy rainfall periodically converts parts of the forested region to swamp. ...

Bamboo leaf ash as the stabilizer for soft soil treatment

NASA Astrophysics Data System (ADS)

Rahman, A. S. A.; Jais, I. B. M.; Sidek, N.; Ahmad, J.; Rosli, M. I. F.

2018-04-01

Soft soil is a type of soil that have the size of particle less than 0.063mm. The strength of the soft soil does not fulfil the requirement for construction. The present of soft soil at the construction site always give a lot of problems and issues to geotechnical sector. Soil settlement is one of the problems that related to soft soil. The determination of the soft soil physical characteristics will provide a detail description on its characteristic. Soft soil need to be treated in order to gain the standard strength for construction. One of the method to strengthen the soft soil is by using pozzolanic material as a treatment method for soft soil. Furthermore bamboo leaf ash is one of the newly founded materials that contain pozzolanic material. Any material that consist of Silicon Dioxide (SiO2) as the main component and followed by Aluminium Oxide (Al2O3) and Iron Oxide (Fe2O3) are consider as pozzolanic material. Bamboo leaf ash is mix with the cement as the treatment material. Bamboo leaf ash will react with the cement to produce additional cement binder. Thus, it will increase the soil strength and will ease the geotechnical sector to achieve high quality of construction product.

Coatal salt marshes and mangrove swamps in China

NASA Astrophysics Data System (ADS)

Yang, Shi-Lun; Chen, Ji-Yu

1995-12-01

Based on plant specimen data, sediment samples, photos, and sketches from 45 coastal crosssections, and materials from two recent countrywide comprehensive investigations on Chinese coasts and islands, this paper deals with China’s vegetative tidal-flats: salt marshes and mangrove swamps. There are now 141700 acres of salt marshes and 51000 acres of mangrove swamps which together cover about 30% of the mud-coast area of the country and distribute between 18°N (Southern Hainan Island) and 41 °N (Liaodong Bay). Over the past 45 years, about 1750000 acres of salt marshes and 49400 acres of mangrove swamps have been reclaimed. The 2.0×109 tons of fine sediments input by rivers into the Chinese seas form extensive tidal flats, the soil basis of coastal helophytes. Different climates result in the diversity of vegetation. The 3˜8 m tidal range favors intertidal zone development. Of over 20 plant species in the salt marshes, native Suaeda salsa, Phragmites australis, Aeluropus littoralis, Zoysia maerostachys, Imperata cylindrica and introduced Spartina anglica are the most extensive in distribution. Of the 41 mangrove swamps species, Kandelia candel, Bruguiera gymnorrhiza, Excoecaria agallocha and Avicennia marina are much wider in latitudinal distribution than the others. Developing stages of marshes originally relevant to the evolution of tidal flats are given out. The roles of pioneer plants in decreasing flood water energy and increasing accretion rate in the Changjiang River delta are discussed.

Air Cushion Crash Rescue Vehicle (ACCRV)

DTIC Science & Technology

1987-10-01

capability to operate over rough and low strength ground surfaces, especially soft, wet ground or marsh and snow, with no capability for overwater...operation. In a wartime environment , fire fighting and res- cue will be further restricted because of craters, debris or unexploded bombs. Improved...swamps and, of course, in more conventional environments on or about airports. The integration of an air cushion system with a paddle track propulsor

Making Your School Site an Environmental Smorgasboard.

ERIC Educational Resources Information Center

Carman, Sam

1986-01-01

Describes ways to enhance a school's outdoor facilities to provide more educational opportunities: nesting boxes, ground water monitoring holes, nature's "swamp shop," soil studies, weather stations, wildlife habitat improvement, forestry practices, aquatic resources, archaeological dig sites, horticulture demonstration areas, outdoor…

Differences in impacts of Hurricane Sandy on freshwater swamps on the Delmarva Peninsula, Mid−Atlantic Coast, USA

USGS Publications Warehouse

Middleton, Beth A.

2016-01-01

Hurricane wind and surge may have different influences on the subsequent composition of forests. During Hurricane Sandy, while damaging winds were highest near landfall in New Jersey, inundation occurred along the entire eastern seaboard from Georgia to Maine. In this study, a comparison of damage from salinity intrusion vs. wind/surge was recorded in swamps of the Delmarva Peninsula along the Pocomoke (MD) and Nanticoke (DE) Rivers, south of the most intense wind damage. Hickory Point Cypress Swamp (Hickory) was closest to the Chesapeake Bay and may have been subjected to a salinity surge as evidenced by elevated salinity levels at a gage upstream of this swamp (storm salinity = 13.1 ppt at Nassawango Creek, Snow Hill, Maryland). After Hurricane Sandy, 8% of the standing trees died at Hickory including Acer rubrum, Amelanchier laevis, Ilex spp., and Taxodium distichum. In Plot 2 of Hickory, 25% of the standing trees were dead, and soil salinity levels were the highest recorded in the study. The most important variables related to structural tree damage were soil salinity and proximity to the Atlantic coast as based on Stepwise Regression and NMDS procedures. Wind damage was mostly restricted to broken branches although tipped−up trees were found at Hickory, Whiton and Porter (species: Liquidamabar styraciflua, Pinus taeda, Populus deltoides, Quercus pagoda and Ilex spp.). These trees fell mostly in an east or east−southeast direction (88o−107o) in keeping with the wind direction of Hurricane Sandy on the Delmarva Peninsula. Coastal restoration and management can be informed by the specific differences in hurricane damage to vegetation by salt versus wind.

Nutrient and salt relations of Pterocarpus officinalis L. in coastal wetlands of the Caribbean: assessment through leaf and soil analyses.

Treesearch

Ernesto Medina; Elvira Cuevas; Ariel Lugo

2007-01-01

Pterocarpus officinalis L. is a dominant tree of freshwater coastal wetlands in the Caribbean and the Guiana regions. It is frequently associated with mangroves in areas with high rainfall and/or surface run-off. We hypothesized that P. officinalis is a freshwater swamp species that when occurring in association with mangroves occupies low-salinity soil microsites, or...

Mapping Upper Amazon Palm Swamps with Spaceborne L-band Synthetic Aperture Radar

NASA Astrophysics Data System (ADS)

Pinto, N.; McDonald, K. C.; Podest, E.; Schroeder, R.; Zimmermann, R.; Horna, V.

2010-12-01

Palm swamp ecosystems are widespread in the Amazon basin, forming where seasonal flooding is moderate and surface inundation persists. Recent studies suggest that palm swamps have a disproportional role on tropical biogeochemistry: the combination of persistently saturated soils, warm temperatures, and low oxygen soils can support significant land-atmosphere methane flux. Potential impacts of climate change on these ecosystems include changes in temperature and precipitation regimes that influence primary productivity and flood extent significantly, potentially reversing net land-atmosphere carbon exchanges regionally. Data acquired from Earth-orbiting satellites provides the opportunity to characterize vegetation structure and monitor surface inundation independently of cloud cover. Building on efforts under our NASA MEaSUREs project for assembly of a global-scale Earth System Data Record (ESDR) of inundated wetlands, we develop and evaluate a systematic approach to map the distribution and composition of palm swamps in the upper Amazon using data sets from JAXA’s Advanced Land Observing Satellite (ALOS) Phased Array L-Band SAR (PALSAR). Our input dataset consists of HH backscatter images acquired in 2007 and 2009. Ground measurements for training were obtained from a study site near Loreto, Peru (4.43S 75.34W) containing the palm species Mauritia flexuosa. The ALOS PALSAR images are first averaged temporally and spatially. We then develop ancillary data layers of flood extent, distance from open water, and SAR image texture. The PALSAR data and derived ancillary layers are combined with MODIS Vegetation Indices and SRTM elevation and input in a classification framework. Since palm swamps are found in persistently flooded areas, we evaluate the potential of identifying and mapping these ecosystems using multi-temporal SAR-based flood extent maps. We conclude by comparing the performance between a decision-tree supervised vs. unsupervised approach and by quantifying model accuracy on a second site in Puerto Maldonado (12.38S 70.45W). This work has been undertaken in part within the framework of the JAXA ALOS Kyoto & Carbon Initiative. ALOS PALSAR data have been provided by JAXA EORC. This work was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Throughfall and stemflow dynamics in a riparian cedar swamp: possible ecohydrological feedbacks

NASA Astrophysics Data System (ADS)

Duval, T. P.

2012-12-01

Partitioning of rainfall through forest canopies as throughfall and stemflow have deservedly been the subject of much research in the past; however, very little is known about the fluxes of water and solutes through forested wetland communities. Temperate swamps are characterized by intermittent canopy coverage, with areas that are denser than upland forests of similar species, but also contain canopy gaps of meadow and marsh communities,. Understanding the role of vegetation on the distribution of precipitation in these ecosystems is necessary to effectively constrain water balance estimates and predict possible community responses to shifting climate regimes. This study examines throughfall, stemflow, and interception dynamics in a riparian cedar swamp in Alliston, Ontario, Canada over the 2012 growing season. Throughfall averaged 76 % of above-canopy rainfall; however, there were spatial-magnitude interaction variations within the swamp. For events less than 20 mm, between 17 and 75 % of the measured swamp floor received greater depth of rain than above the canopy, whereas for events greater than 20 mm only between 2 and 23 % of the sampled swamp floor received more water than the actual event. The observed spatial variability in throughfall was not related to leaf area index, suggesting remote sensing modelling efforts may not be an accurate method for quantification of wetland precipitation dynamics. Stemflow along the predominantly cedar trees averaged 5 %; therefore, net precipitation on a seasonal basis in this cedar swamp was 81 % of above canopy rainfall. Throughfall DOC and total nitrogen concentrations averaged 31 and 2.2 mg/L, respectively, with stemflow DOC and TN concentrations averaging 109 and 6.5 mg/L, respectively. These values are much higher than reported for upland forest species. In general, throughfall magnitudes increased and solute concentrations decreased with increasing distance from the existing forest boles. The delivery of high reactive-solute concentrations through stemflow and comparatively reduced throughfall water fluxes closer to the trees may represent an ecohydrological feedback to cedar maintenance in swamp ecosystems by enriching the root zone soil with nutrients and shedding water away from the roots in a system where the presence of water is viewed as a stress to optimal growth.

Hydrologic controls on Congo River particulate organic carbon source and reservoir age

NASA Astrophysics Data System (ADS)

Hemingway, J. D.; Schefuß, E.; Spencer, R. G.; Dinga, B. J.; Eglinton, T. I.; McIntyre, C.; Galy, V.

2016-12-01

Tropical rivers are a major source of organic matter (OM) to the coastal ocean and play a large role in the global carbon cycle. As such, it is critical to understand the sources, sinks, and transformations of OM during fluvial transit over seasonal and inter-annual timescales. Here we present dissolved organic carbon (DOC) concentrations, particulate OM (POM) composition (δ13C, δ15N, Δ14C, N/C), and glycerol dialkyl glycerol tetraether (GDGT) biomarker distributions from a 34-month time-series near the mouth of the Congo River. An end-member mixing model based on δ13C and N/C indicates that exported POM is consistently dominated by C3 tropical rainforest soil inputs, with increasing contributions by C3 tropical plant vegetation and decreasing contributions by autochthonous phytoplankton at high discharge. Calculated Δ14C values of the C3-soil end member reveal significant and variable pre-aging prior to export, especially during the year 2011 when southern-hemisphere discharge reached record lows (mean = -176‰, standard deviation = 93‰). In contrast, Δ14C values were stable near -50‰ between January and June 2013 when southern-hemisphere discharge was highest. These results indicate that headwater POM is diluted and/or overprinted by pre-aged soils during transit through the Cuvette Congolaise swamp forest, while left-bank tributaries export significantly less pre-aged material. GDGT distributions are in agreement, as the methylation and cyclization of branched tetraethers and the GDGT-0/crenarchaeol ratio reflect a significant incorporation of compounds produced in permanently inundated Cuvette Congolaise swamp-forest soils when discharge through this region is high, especially in 2011. This study provides a mechanistic link between hydrology and carbon cycling in the world's second largest tropical river and suggests that, if recent observed decreases in springtime precipitation over the Congo basin persist, future hydrologic conditions will further bias toward export of protracted, swamp-forest-derived OM sources.

Global carbon sequestration in tidal, saline wetland soils

USGS Publications Warehouse

Chmura, G.L.; Anisfeld, S.C.; Cahoon, D.R.; Lynch, J.C.

2003-01-01

Wetlands represent the largest component of the terrestrial biological carbon pool and thus play an important role in global carbon cycles. Most global carbon budgets, however, have focused on dry land ecosystems that extend over large areas and have not accounted for the many small, scattered carbon-storing ecosystems such as tidal saline wetlands. We compiled data for 154 sites in mangroves and salt marshes from the western and eastern Atlantic and Pacific coasts, as well as the Indian Ocean, Mediterranean Ocean, and Gulf of Mexico. The set of sites spans a latitudinal range from 22.4??S in the Indian Ocean to 55.5??N in the northeastern Atlantic. The average soil carbon density of mangrove swamps (0.055 ?? 0.004 g cm-3) is significantly higher than the salt marsh average (0.039 ?? 0.003 g cm-3). Soil carbon density in mangrove swamps and Spartina patens marshes declines with increasing average annual temperature, probably due to increased decay rates at higher temperatures. In contrast, carbon sequestration rates were not significantly different between mangrove swamps and salt marshes. Variability in sediment accumulation rates within marshes is a major control of carbon sequestration rates masking any relationship with climatic parameters. Globally, these combined wetlands store at least 44.6 Tg C yr-1 and probably more, as detailed areal inventories are not available for salt marshes in China and South America. Much attention has been given to the role of freshwater wetlands, particularly northern peatlands, as carbon sinks. In contrast to peatlands, salt marshes and mangroves release negligible amounts of greenhouse gases and store more carbon per unit area. Copyright 2003 by the American Geophysical Union.

Environmental Factors that Influence Physiological Functioning of Eight Bottomland Hardwood Species

NASA Astrophysics Data System (ADS)

Kassahun, Z.; Renninger, H. J.

2017-12-01

With increases in extreme precipitation, flooding, and prolonged drought events in the southeastern United States, bottomland hardwood forests are expected to experience a drastic shift in their productivity and composition. As environmental conditions shift, certain tree species may experience an increase in productivity or could be more negatively affected over more resilient species, leading to a shift in species composition, water use, and carbon uptake. The goals of this research were to use sap flow measurements, leaf phenology, and photosynthetic rates to study species-specific responses to environmental drivers. Sap flow of eight co-occurring hardwood species as well as soil moisture and vapor pressure deficit were measured continuously over the course of a calendar year that included drought conditions and extended saturated soil conditions. We found that cherrybark oak used the most water during the growing season, about 20% more water than the next highest consumer, swamp chestnut oak. Given low, ample or saturated soil moisture conditions, we found that sap flow of winged elm, American elm, cherrybark oak, and shagbark hickory exhibited varying relationships with vapor pressure deficit under the different soil moisture conditions. While the relationship between sap flow and vapor pressure deficit did not differ depending on soil moisture in willow oak, swamp chestnut oak, and green ash. This suggests that winged elm, American elm, cherrybark oak, and shagbark hickory may be more negatively affected by drought conditions while willow oak, swamp chestnut oak, and green ash are more drought tolerant. Regarding leaf phenology, willow oak, cherrybark oak, and shagbark hickory were the first to experience leaf abscission at the end of the growing season when extended drought conditions occurred. In terms of leaf gas exchange, green ash exhibited the highest photosynthesis and transpiration rates, resulting in the lowest water-use efficiency compared with other study species. Taken together, these responses can be used to estimate forest water budgets given stand species composition or to predict individual species resilience or adaptation to a changing climate, which can improve land surface models and identify species in this forest type that will be most successful under future climate conditions.

Tree establishment in floodplain agroforestry practices

Treesearch

Daniel C. Dey; John M. Kabrick; Michael A. Gold

2004-01-01

The benefits of soil mounding, a cover crop, and various nursery stock types were evaluated for establishing pin and swamp white oaks in floodplain crop fields. The two stock types were 1-0 bareroot and large (3- and 5-gallon) container seedlings grown by the RPMTM method.

Sharpley’s Bottom Historic Sites Interdisciplinary Investigations, Tombigbee River Multi-Resource District, Alabama and Mississippi. Phase II. Archeological Investigations.

DTIC Science & Technology

1983-10-01

1941; Young ’.4 1961:41-46). The treaty launched a tidal wave of new settlement. Planters from the older seaboard South coveted the rich soils of the...majority of Sharpley’s tenants remained renters with little or no property, victims of chronic debt, overworked soil , and periodic flooding of...Sections 7, 8 and 18 of R. 8E, T. 15S. Major soil types include alluvial land along the riverbanks and in swamps, Eustis loamy sand, and Bibb, Myatt

Archeological Survey of Undeveloped Portions of Eaker Air Force Base, Mississippi County, Arkansas

DTIC Science & Technology

1991-01-25

successional stage plant communities. Research using soils and plant communities to model prehistoric occupation in northeast Arkansas (Dekin et al. 1978; Morse...major floods) since they were laid down. Levee/Swamp Ecotone This modeled macrobiotic community is what Lewis (1974:24-25) has called the Sweetgum-Elm...this modeled stratum are the different environments that were under water prior to drainage, as defined by the soils deposited in slackwater conditions

Determination of methane concentrations in shallow ground water and soil gas near Price, Utah

USGS Publications Warehouse

Naftz, David L.; Hadley, Heidi K.; Hunt, Gilbert L.

1998-01-01

Methane gas, commonly referred to as "natural gas," is being produced from coal beds in central Utah (fig. 1) at an increasing rate since the early 1990s. The methane was generated over millions of years during the formation of coal in the area. Coal originates as plant matter that has been deposited in a swamp-like environment and then decays as it is buried and compressed over geologic time. Giant fossilized footprints in the coal provide evidence that dinosaurs roamed and fed among the plentiful plants in these swamps (Hintze, 1979). Methane and carbon dioxide gas and water are produced in the coal as byproducts of coal formation (Sommer and Gloyn, 1993).

High Throughput Sequencing to Detect Differences in Methanotrophic Methylococcaceae and Methylocystaceae in Surface Peat, Forest Soil, and Sphagnum Moss in Cranesville Swamp Preserve, West Virginia, USA

PubMed Central

Lau, Evan; Nolan, Edward J.; Dillard, Zachary W.; Dague, Ryan D.; Semple, Amanda L.; Wentzell, Wendi L.

2015-01-01

Northern temperate forest soils and Sphagnum-dominated peatlands are a major source and sink of methane. In these ecosystems, methane is mainly oxidized by aerobic methanotrophic bacteria, which are typically found in aerated forest soils, surface peat, and Sphagnum moss. We contrasted methanotrophic bacterial diversity and abundances from the (i) organic horizon of forest soil; (ii) surface peat; and (iii) submerged Sphagnum moss from Cranesville Swamp Preserve, West Virginia, using multiplex sequencing of bacterial 16S rRNA (V3 region) gene amplicons. From ~1 million reads, >50,000 unique OTUs (Operational Taxonomic Units), 29 and 34 unique sequences were detected in the Methylococcaceae and Methylocystaceae, respectively, and 24 potential methanotrophs in the Beijerinckiaceae were also identified. Methylacidiphilum-like methanotrophs were not detected. Proteobacterial methanotrophic bacteria constitute <2% of microbiota in these environments, with the Methylocystaceae one to two orders of magnitude more abundant than the Methylococcaceae in all environments sampled. The Methylococcaceae are also less diverse in forest soil compared to the other two habitats. Nonmetric multidimensional scaling analyses indicated that the majority of methanotrophs from the Methylococcaceae and Methylocystaceae tend to occur in one habitat only (peat or Sphagnum moss) or co-occurred in both Sphagnum moss and peat. This study provides insights into the structure of methanotrophic communities in relationship to habitat type, and suggests that peat and Sphagnum moss can influence methanotroph community structure and biogeography. PMID:27682082

Accumulation and translocation peculiarities of (137)Cs and (40)K in the soil--plant system.

PubMed

Marčiulionienė, Danutė; Lukšienė, Benedikta; Jefanova, Olga

2015-12-01

Long-term investigations (1996-2008) were conducted into the (137)Cs and (40)K in the soil of forests, swamps and meadows in different regions of Lithuania, as well as in the plants growing in these media. The (137)Cs and (40)K activity concentrations, the (137)Cs/(40)K activity concentration ratio and accumulation, and translocation in the system, i.e. from the soil to plant roots to above-ground plant part of these radionuclides, were evaluated after gamma-spectrometric measurements using a high purity germanium (HPGe) detector. Based on the obtained data, it can be asserted that in the tested plant species, the (137)Cs and (40)K accumulation, the transfer from soil to roots and translocation within the plants depend on the plant species and environmental ecological conditions. The (137)Cs/(40)K activity concentration ratios in the same plant species in different regions of Lithuania are different and this ratio depends on the biotope (forest, swamp or meadow) in which the plant grows and on the location of the growing region. Based on the determined trends of statistically reliable inverse dependence between the activity concentrations in both soil and plants, it can be stated that the exchange of (137)Cs and (40)K in plants and soil is different. Different accumulations and translocations of investigated radionuclides in the same plant species indicate diverse biological metabolism of (137)Cs and its chemical analogue (40)K in plants. A competitive relationship exists between (137)Cs and (40)K in plants as well as in the soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preduction of Vehicle Mobility on Large-Scale Soft-Soil Terrain Maps Using Physics-Based Simulation

DTIC Science & Technology

2016-08-02

PREDICTION OF VEHICLE MOBILITY ON LARGE-SCALE SOFT- SOIL TERRAIN MAPS USING PHYSICS-BASED SIMULATION Tamer M. Wasfy, Paramsothy Jayakumar, Dave...NRMM • Objectives • Soft Soils • Review of Physics-Based Soil Models • MBD/DEM Modeling Formulation – Joint & Contact Constraints – DEM Cohesive... Soil Model • Cone Penetrometer Experiment • Vehicle- Soil Model • Vehicle Mobility DOE Procedure • Simulation Results • Concluding Remarks 2UNCLASSIFIED

Surface energy exchanges over contrasting vegetation types on a subtropical sand island

NASA Astrophysics Data System (ADS)

Gray, Michael; McGowan, Hamish; Lowry, Andrew; Guyot, Adrien

2017-04-01

The surface energy balance of subtropical coastal vegetation communities has thus far received little attention. Here we present a multi-year observational data set using the eddy covariance method to quantify for the first time the surface energy balance over three contrasting vegetation types on a subtropical sand island in eastern Australia: a periodically inundated sedge swamp, an exotic pine plantation and a coastal heath. Maximum daily sensible heat flux varied between sites but was typically > 280 Wm-2 in the coastal heath and pine plantation but no more than 250 Wm-2 in the swamp when dry and < 110 Wm-2 when inundated. Maximum daily latent heat flux was up to 300 Wm-2 in the coastal heath and pine, but in the swamp it was up to 250 Wm-2 when dry and 209 Wm-2 when inundated. On seasonal timescales, the coastal heath and swamp were both found to be dominated by latent heat flux, with Bowen ratio (β) < 1, whereas the pine plantation typically exhibited β > 1. The partitioning of energy, as represented by β, is similar to a variety of Australian ecosystems, and a range of coastal vegetation types in other latitudes, but differs from other tropical or subtropical locations which have strongly seasonal rainfall patterns and therefore a switch from β > 1 before rainfall to β < 1 afterwards. The energy fluxes over the three vegetation types responded to seasonal changes in background meteorology with the most important influences being net radiation, absolute humidity, and rainfall. The main factor differentiating the sites was soil water content, with the remnant coastal heath and swamp having ready access to water but the exotic pine plantation having much drier soils. Should the current balance between remnant vegetation and the pine plantation undergo changes there would be a corresponding shift in the surface energy balance of the island as a whole, and altered plant water use may lead to reduced water table depth, important because the groundwater of the local islands is used as part of a regional water grid. A better understanding of the response of coastal vegetation to atmospheric forcing will enable more informed decision making on land use changes, as coastal regions the world over face development pressure.

Impact of logging on a mangrove swamp in south Mexico: cost/benefit analysis.

PubMed

Tovilla-Hernández, C; Espino de la Lanza, G; Orihuela-Belmonte, D E

2001-06-01

Environmental changes caused by logging in a mangrove swamp were studied in Barra de Tecoanapa, Guerrero, Mexico. Original forest included Rhizophora mangle, Laguncularia racemosa, Avicennia germinans and halophytic vegetation, and produced wood (164.03 m3/ha) and organic matter (3.9 g/m2/day). A total of 3.5 tons of wood per year were harvested from this area. Later, an average of 2,555 kg of maize per planting cycle were obtained (market value of 88 USD). Succession when the area was abandoned included strictly facultative and glycophyte halophytes (16 families, Cyperaceae and Poaceae were the best represented). After logging, temperatures increased 13 degrees C in the soil and 11 degrees C in the air, whereas salinity reached 52 psu in the dry season. These modified soil color and sand content increased from 42.6 to 63.4%. Logging was deleterious to species, habitat, biogeochemical and biological cycles, organic matter production, seeds, young plants, genetic exchange conservation of soil and its fertility, coastal protection, and aesthetic value; 3,000 m2 had eroded as the river advanced towards the deforested area (the cost/benefit analysis showed a ratio of 246:1). There was long-term economic loss for the community and only 30% of the site has recovered after five years.

Effect of hydrological conditions on nitrous oxide, methane, and carbon dioxide dynamics in a bottomland hardwood forest and its implication for soil carbon sequestration

USGS Publications Warehouse

Yu, K.; Faulkner, S.P.; Baldwin, M.J.

2008-01-01

This study was conducted at three locations in a bottomland hardwood forest with a distinct elevation and hydrological gradient: ridge (high, dry), transition, and swamp (low, wet). At each location, concentrations of soil greenhouse gases (N2O, CH4 , and CO2), their fluxes to the atmosphere, and soil redox potential (Eh) were measured bimonthly, while the water table was monitored every day. Results show that soil Eh was significantly (P transition > ridge location. The ratio CO2/CH4 production in soil is a critical factor for evaluating the overall benefit of soil C sequestration, which can be greatly offset by CH4 production and emission. ?? Journal compilation ?? 2008 Blackwell Publishing.

Depressional wetland vegetation types: a question of plant commmunity development

Treesearch

Katherine L. Kirkman; Charles P. Goebel; Larry West; Mark B. Drew; Brian Palik

2000-01-01

When wetland restoration includes re-establishing native plant taxa as an objective, an understanding of the variables driving the development of plant communities is necessary. With this in mind, we examined soil and physiographic characteristics of depressional wetlands of three vegetation types (cypressgum swamps, cypress savannas, and grass-sedge marshes) located...

Co-assessment of biomass and soil organic carbon stocks in a future reservoir area located in Southeast Asia.

PubMed

Descloux, Stéphane; Chanudet, Vincent; Poilvé, Hervé; Grégoire, Alain

2011-02-01

An assessment of the organic carbon stock present in living or dead vegetation and in the soil on the 450 km2 of the future Nam Theun 2 hydroelectric reservoir in Lao People's Democratic Republic was made. Nine land cover types were defined on the studied area: dense, medium, light, degraded, and riparian forests; agricultural soil; swamps; water; and others (roads, construction sites, and so on). Their geographical distribution was assessed by remote sensing using two 2008 SPOT 5 images. The area is mainly covered by dense and light forests (59%), while agricultural soil and swamps account for 11% and 2%, respectively. For each of these cover types, except water, organic carbon density was measured in the five pools defined by the Intergovernmental Panel on Climate Change: aboveground biomass, litter, deadwood, belowground biomass, and soil organic carbon. The area-weighted mean carbon densities for these pools were estimated at 45.4, 2.0, 2.2, 3.4, and 62.2 tC/ha, respectively, i.e., a total of about 115±15 tC/ha for a soil thickness of 30 cm, corresponding to a total flooded organic carbon stock of 5.1±0.7 MtC. This value is much lower than the carbon density for some South American reservoirs for example where total organic carbon stocks range from 251 to 326 tC/ha. It can be mainly explained by (1) the higher biomass density of South American tropical primary rainforest than of forests in this study and (2) the high proportion of areas with low carbon density, such as agricultural or slash-and-burn zones, in the studied area.

Latitudinal variation in carbon storage can help predict changes in swamps affected by global warming

USGS Publications Warehouse

Middleton, Beth A.; McKee, Karen

2004-01-01

Plants may offer our best hope of removing greenhouse gases (gases that contribute to global warming) emitted to the atmosphere from the burning of fossil fuels. At the same time, global warming could change environments so that natural plant communities will either need to shift into cooler climate zones, or become extirpated (Prasad and Iverson, 1999; Crumpacker and others, 2001; Davis and Shaw, 2001). It is impossible to know the future, but studies combining field observation of production and modeling can help us make predictions about what may happen to these wetland communities in the future. Widespread wetland types such as baldcypress (Taxodium distichum) swamps in the southeastern portion of the United States could be especially good at carbon sequestration (amount of CO2 stored by forests) from the atmosphere. They have high levels of production and sometimes store undecomposed dead plant material in wet conditions with low oxygen, thus keeping gases stored that would otherwise be released into the atmosphere (fig. 1). To study the ability of baldcypress swamps to store carbon, our project has taken two approaches. The first analysis looked at published data to develop an idea (hypothesis) of how production levels change across a temperature gradient in the baldcypress region (published data study). The second study tested this idea by comparing production levels across a latitudinal range by using swamps in similar field conditions (ongoing carbon storage study). These studies will help us make predictions about the future ability of baldcypress swamps to store carbon in soil and plant biomass, as well as the ability of these forests to shift northward with global warming.

Environmental gradients and identification of wetlands in north-central Florida

USGS Publications Warehouse

Davis, M.M.; Sprecher, S.W.; Wakeley, J.S.; Best, G.R.

1996-01-01

Vegetation composition, soil morphology, and hydrology were characterized along wetland-to-upland gradients at six forested sites in north-central Florida to compare results of Federal wetland delineation methods with 3–5 yr of hydrologic data. Wetland and non-wetland identifications were supported by hydrology data in eight of nine plant communities. Lack of hydric soil indicators and hydrophytic vegetation in two upland communities (scrub and mixed mesic hardwoods) agreed with a deep water table. Six wetland communities (cypress dome, cypress strand, bayhead, cypress/bayhead, red maple/oak swamp, and cedar swamp) with field indicators of wetland hydrology, hydrophytic vegetation, and hydric soils were inundated or had water tables at or near the ground surface at least 5% of the growing season in most years., Flatwoods communities, however, occurred at intermediate positions on the moisture gradient and could not be consistently identified as wetland or upland communities. Identification of flatwoods as wetlands depended on wetland delineation method and was not usually supported by hydrologic measurements. In the flatwoods community, soil properties and vegetation composition were correlated with the mean and standard deviation of water-table depths, as well as the depth continuously exceeded by the water table at least 5% of the growing season in most years. Various hydrologic parameters need to be considered in addition to the 5% exceedence level currently used in Federal wetland delineation guidance when characterizing wetland conditions in low-gradient areas such as flatwoods.

A 15,400-year record of environmental magnetic variations in sub-alpine lake sediments from the western Nanling Mountains in South China: Implications for palaeoenvironmental changes

NASA Astrophysics Data System (ADS)

Zhong, Wei; Wei, Zhiqiang; Shang, Shentan; Ye, Susu; Tang, Xiaowen; Zhu, Chan; Xue, Jibin; Ouyang, Jun; Smol, John P.

2018-04-01

A detailed environmental magnetic investigation has been performed on a sub-alpine sedimentary succession deposited over the past 15,400 years in Daping Swamp in the western Nanling Mountains of South China. Magnetic parameters reveal that fine grains of pseudo-single domain (PSD) magnetite or titanomagnetite are the dominant magnetic minerals in the lake sediments and surface soils collected from the catchment, which suggests that magnetic minerals in lake sediments mainly originated from surface soil erosion of the catchment. Variation of surface runoff caused by rainfall is interpreted as the main process for transportation of weathered soils into the lake. In the Last Deglacial period (LGP, 15,400-11,500 cal a BP), the influx of magnetic minerals of detrital material may have been significantly affected by the severe dry and cold conditions of the Last Glacial Maximum. Stabilised conditions of the catchment associated with increased vegetation coverage (e.g., 8000-4500 and 2500-1000 cal a BP) limited the input of magnetic minerals. Intensive soil erosion caused by increased human activity may have given rise to abnormal increases in multiple magnetic parameters after 1000 cal a BP. Because changes in runoff and vegetation coverage are closely related to Asian summer monsoon (ASM) intensity, the sedimentary magnetism of Daping Swamp provides another source of information to investigate the evolution of the ASM.

The Physical Behavior of Stabilised Soft Clay by Electrokinetic Stabilisation Technology

NASA Astrophysics Data System (ADS)

Azhar, A. T. S.; Nordin, N. S.; Azmi, M. A. M.; Embong, Z.; Sunar, N.; Hazreek, Z. A. M.; Aziman, M.

2018-04-01

Electrokinetic Stabilisation (EKS) technology is the combination processes of electroosmosis and chemical grouting. This technique is most effective in silty and clayey soils where the hydraulic conductivity is very low. Stabilising agents will assist the EKS treatment by inducing it into soil under direct current. The movement of stabilising agents into soil is governed by the principle of electrokinetics. The aim of this study is to evaluate the physical behavior of soft soil using the EKS technology as an effective method to strengthen soft clay soils with calcium chloride (CaCl2) as the stabilising agent. Stainless steel plates were used as the electrodes, while 1.0 mol/l of CaCl2 was used as the electrolyte that fed at the anode compartment. Soft marine clay at Universiti Tun Hussein Onn Malaysia was used as the soil sample. The EKS treatment was developed at Research Centre for Soft Soil (RECESS), UTHM with a constant voltage gradient (50 V/m) in 21 days. The result shows that the shear strength of treated soil was increased across the soil sample. The treated soil near the cathode showed the highest value of shear strength (24.5 – 33 kPa) compared with the anode and in the middle of the soil sample.

New England wildlife: a model for ecosystem management – ECOSEARCH (version 1)

Treesearch

Henry L. Short; Jay B. Hestbeck; Richard M. DeGraaf

2001-01-01

This volume describes how ECOSEARCH species-habitat models are developed using information about the natural history of species, habitat descriptions, and specific descriptors for soils, topography, water regimes, and vertical habitat structure. Also, examples are provided that demonstrate the impacts of: 1) converting a wooded swamp into a recreational lake with...

Establishing the Marcell Experimental Forest: Threads in time. Chapter 1.

Treesearch

Elon S. Verry; Roger R. Bay; Don H. Boelter

2011-01-01

The Marcell Experimental Forest (MEF), carved out of northern Minnesota's aspen, pine, and swamp forests in 1959, turned 50 years old in 2009. Established to investigate the role of peatlands in the northern Lake States region, its instrumented watersheds include nutrient-poor bogs and nutrient-rich fens (organic-soil wetlands) along with glacial-till moraines and...

The role of large container seedlings in afforesting oaks in bottomlands

Treesearch

Daniel C. Dey; John M. Kabrick; Michael Gold

2006-01-01

We planted large container (RPM®) and 1-0 bareroot seedlings of pin oak (Quercus palustris Muenchh.) and swamp white oak (Q. bicolor Willd.) in crop fields in the Missouri River floodplain. We also evaluated the benefits of soil mounding and a grass (Agrostis gigantea Roth) cover crop. RPM®) oak seedlings had significantly greater...

Investigation of Stabilised Batu Pahat Soft Soil Pertaining on its CBR and Permeability Properties for Road Construction

NASA Astrophysics Data System (ADS)

Mohd Idrus, M. M.; Singh, J. S. M.; Musbah, A. L. A.; Wijeyesekera, D. C.

2016-07-01

Soil stabilization by adding materials such as cement, lime and bitumen is one of the effective methods for improving the geotechnical properties of soils [11] Nano-particle is one of the newest additives and many studies about using nano-particle in soil improvement has been done but it was given less attention when soft clay soils stabilization is concerned. To evaluate the strength characteristics of stabilized Batu Pahat soft clay, laboratory investigation on early strength gained by the stabilized soil must be conducted to formulate a suitable and economical mix design [10]. To achieve such purpose, the study examined the effect of NanoClay on the California Bearing Ratio and the Permeability of soft clay. The results gained shows that the Nano-Clay is able to increase the strength of the soft clay [9]. The California Bearing Ratio of the soil is increase significantly where the results for the highest percentage of admixture is 14.4% while the permeability of the soil decreases significantly with increasing Nano-Clay whereby the results of the highest percentage of admixture is 2.0187x10-11 m/s. After doing this research, it is proven that Nano-clay can contribute towards better soil stabilization and enhance the quality of soil as subgrade and foundation at large.

Identifying sources of acidity and spatial distribution of acid sulfate soils in the Anglesea River catchment, southern Australia

NASA Astrophysics Data System (ADS)

Wong, Vanessa; Yau, Chin; Kennedy, David

2015-04-01

Globally, coastal and estuarine floodplains are frequently underlain by sulfidic sediments. When exposed to oxygen, sulfidic sediments oxidise to form acid sulfate soils, adversely impacting on floodplain health and adjacent aquatic ecoystems. In eastern Australia, our understanding of the formation of these coastal and estuarine floodplains, and hence, spatial distribution of acid sulfate soils, is relatively well established. These soils have largely formed as a result of sedimentation of coastal river valleys approximately 6000 years BP when sea levels were one to two metres higher. However, our understanding of the evolution of estuarine systems and acid sulfate soil formation, and hence, distribution, in southern Australia remains limited. The Anglesea River, in southern Australia, is subjected to frequent episodes of poor water quality and low pH resulting in closure of the river and, in extreme cases, large fish kill events. This region is heavily reliant on tourism and host to a number of iconic features, including the Great Ocean Road and Twelve Apostles. Poor water quality has been linked to acid leakage from mining activities and Tertiary-aged coal seams, peat swamps and acid sulfate soils in the region. However, our understanding of the sources of acidity and distribution of acid sulfate soils in this region remains poor. In this study, four sites on the Anglesea River floodplain were sampled, representative of the main vegetation communities. Peat swamps and intertidal marshes were both significant sources of acidity on the floodplain in the lower catchment. However, acid neutralising capacity provided by carbonate sands suggests that there are additional sources of acidity higher in the catchment. This pilot study has highlighted the complexity in the links between the floodplain, upper catchment and waterways with further research required to understand these links for targeted acid management strategies.

Linking hard and soft traits: Physiology, morphology and anatomy interact to determine habitat affinities to soil water availability in herbaceous dicots.

PubMed

Belluau, Michaël; Shipley, Bill

2018-01-01

Species' habitat affinities along environmental gradients should be determined by a combination of physiological (hard) and morpho-anatomical (soft) traits. Using a gradient of soil water availability, we address three questions: How well can we predict habitat affinities from hard traits, from soft traits, and from a combination of the two? How well can we predict species' physiological responses to drought (hard traits) from their soft traits? Can we model a causal sequence as soft traits → hard traits → species distributions? We chose 25 species of herbaceous dicots whose affinities for soil moisture have already been linked to 5 physiological traits (stomatal conductance and net photosynthesis measured at soil field capacity, water use efficiency, stomatal conductance and soil water potential measured when leaves begin to wilt). Under controlled conditions in soils at field capacity, we measured five soft traits (leaf dry matter content, specific leaf area, leaf nitrogen content, stomatal area, specific root length). Soft traits alone were poor predictors (R2 = 0.129) while hard traits explained 48% of species habitat affinities. Moreover, hard traits were significantly related to combinations of soft traits. From a priori biological knowledge and hypothesized ecological links we built a path model showing a sequential pattern soft traits → hard traits → species distributions and accounting for 59.6% (p = 0.782) of habitat wetness. Both direct and indirect causal relationships existed between soft traits, hard traits and species' habitat preferences. The poor predictive abilities of soft traits alone were due to the existence of antagonistic and synergistic direct and indirect effects of soft traits on habitat preferences mediated by the hard traits. To obtain a more realistic model applicable to a population level, it has to be tested in an experiment including species competition for water supply.

Palm Swamp Wetland Ecosystems of the Upper Amazon: Characterizing their Distribution and Inundation State Using Multiple Resolution Microwave Remote Sensing

NASA Astrophysics Data System (ADS)

Podest, E.; McDonald, K. C.; Schröder, R.; Pinto, N.; Zimmermann, R.; Horna, V.

2011-12-01

Palm swamp wetlands are prevalent in the Amazon basin, including extensive regions in northern Peru. These ecosystems are characterized by constant surface inundation and moderate seasonal water level variation. The combination of constantly saturated soils, giving rise to low oxygen conditions, and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, knowledge of their spatial extent and inundation state is crucial for assessing the associated land-atmosphere carbon exchange. Precise spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We are developing a remote sensing methodology using multiple resolution microwave remote sensing data to determine palm swamp distribution and inundation state over focus regions in the Amazon basin in northern Peru. For this purpose, two types of multi-temporal microwave data are used: 1) high-resolution (100 m) data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR) to derive maps of palm swamp extent and inundation from dual-polarization fine-beam and multi-temporal HH-polarized ScanSAR, and 2) coarse resolution (25 km) combined active and passive microwave data from QuikSCAT and AMSR-E to derive inundated area fraction on a weekly basis. We compare information content and accuracy of the coarse resolution products to the PALSAR-based datasets to ensure information harmonization. The synergistic combination of high and low resolution datasets will allow for characterization of palm swamps and assessment of their flooding status. This work has been undertaken partly within the framework of the JAXA ALOS Kyoto & Carbon Initiative. PALSAR data have been provided by JAXA/EORC. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Moist-Soil Impoundments for Wetland Wildlife.

DTIC Science & Technology

1999-10-01

cutgrass Spikerush (0 <D *-» CO Beakrush Black willow Rushes American lotus Buttonbush Marsh purslane Swamp smartweed Beggarticks Common...Pennsylvania Curltop ladysthumb Sprangletop Arrowhead Purple loosestrife Redroot flatsedge Tooth-cup / Bulrush Cattail Marsh purslane Pondweed...30 to 60 cm (12 to 24 in.) or by salinities of 60 parts per thousand. It can be eliminated by burning or mowing, followed by com- paction and

Traditional adaptation to natural processes of erosion and sedimentation on Yap Island

Treesearch

Marjorie C. Falanruw

1990-01-01

Yap is a high island with a mean annual rainfall of 3040 mm and considerable potential for erosion. The island once supported a dense population with a nature-intensive technology. The traditional food production system incorporated tree gardens which mimic natural forests in intercepting rainfall and holding the soil, and taro patch system which mimic swamp forests...

Utilization of ERTS data to detect plant diseases and nutrient deficiencies, soil types and moisture levels

NASA Technical Reports Server (NTRS)

Parks, W. L. (Principal Investigator); Sewell, J. I.; Hilty, J. W.; Rennie, J. C.

1973-01-01

The author has identified the following significant results. A significant finding to date is the delineation of the Memphis soil association in Obion County, Dyer County, and in portions of Kentucky. This soil association was delineated mechanically through the use of imagery in the digital tape format, appropriate computer software, and an IBM/360/05 computer. The Waverly-Swamp association as well as the Obion River have been identified on the ERTS-1 imagery as well as on the computer printout. These findings demonstrate the feasibility of delineating major soil associations through vegetative cover common to the association. Channel 7 provides the most information for studies of this type. Computer density printouts assist markedly in making density separations and delineating major soil moisture differences; however, signatures for soil moisture classification for this area of mixed land uses in relatively small tracts have not yet been developed.

Selected papers in the hydrologic sciences 1984; July 1984

USGS Publications Warehouse

Meyer, Eric L.

1984-01-01

The rapid, accurate measurement of the oxygen content of soil gas in the unsaturated zone or dissolved oxygen in soil water in the saturated zone can be useful in wetland vegetation studies. A method has been devised and tested in the Great Dismal Swamp, a wetland with fine silt-clay and organic soils, that appears to provide good results. A 60-milliliter sample of soil gas or water is withdrawn from permanently installed chambers at various depths in the soil profile. The oxygen concentration of air samples is measured with a specially constructed analyzer cell fitted to the polarographic oxygen electrode of a portable oxygen meter. The dissolved oxygen concentration of water samples is measured directly with the oxygen electrode while stirring the sample in a 32-milliliter glass bottle with a portable magnetic stirrer. Field tests with duplicate chamber installations showed that consistent results are obtained for soil gas and water.

A Biogeotechnical approach to Stabilize Soft Marine Soil with a Microbial Organic Material called Biopolymer

NASA Astrophysics Data System (ADS)

Chang, I.; Cho, G. C.; Kwon, Y. M.; Im, J.

2017-12-01

The importance and demands of offshore and coastal area development are increasing due to shortage of usable land and to have access to valuable marine resources. However, most coastal soils are soft sediments, mainly composed with fines (silt and clay) and having high water and organic contents, which induce complicated mechanical- and geochemical- behaviors and even be insufficient in Geotechnical engineering aspects. At least, soil stabilization procedures are required for those soft sediments, regardless of the purpose of usage on the site. One of the most common soft soil stabilization method is using ordinary cement as a soil strengthening binder. However, the use of cement in marine environments is reported to occur environmental concerns such as pH increase and accompanying marine ecosystem disturbance. Therefore, a new environmentally-friendly treatment material for coastal and offshore soils. In this study, a biopolymer material produced by microbes is introduced to enhance the physical behavior of a soft tidal flat sediment by considering the biopolymer rheology, soil mineralogy, and chemical properties of marine water. Biopolymer material used in this study forms inter-particle bonds between particles which is promoted through cation-bridges where the cations are provided from marine water. Moreover, biopolymer treatment renders unique stress-strain relationship of soft soils. The mechanical stiffness (M) instantly increase with the presence of biopolymer, while time-dependent settlement behavior (consolidation) shows a big delay due to the viscous biopolymer hydrogels in pore spaces.

Magruder Park Swamp

USGS Publications Warehouse

Hotchkiss, N.; Uhler, F.M.

1967-01-01

The last Tuesday in August, between five-thirty and seven in the evening, we zigzaged through this glorious jungle, attended by a family of Wood Pewees for whom we seemed to be stirring up a feast of flying insects. There was gentle background music by Mole Crickets. A few steps in from the playing field and we were out of sight in ten-foot-high Cattails. All through, we met -- as high as we, or higher--clumped Cinnamon Ferns, deep-rose Joe Pye Weed, and orange, pendent flowers of Jewelweed (first cousins to Balsam and Sultana). Here and there were soft, white spikes of Canadian Burnet, a rare plant hereabouts, and deep purple Ironweed. Dense-foliaged Hempweed climbed over bushes and up small trees, filling the air with its delicate fragrance. Arrowleaf Tear-thumb snatched at us with tiny prongs on its angled stems. Once in a while we tripped over huge sedge tussocks, half-hidden in the tangle. A few times we steered around a small bush of Poison Sumac. The next day We remembered seeing ninety kinds of plants on this hasty trip. Skunk Cabbage leaves recalled April, when a person, from the edge of the lawn, could see huge clumps of them all the way across the swamp. The sky had been washed by last week's downpours; scattered Gums were reddening; and Maples were getting ready for crimson beauty a month from now. There wasn't a mosquito! (Ed. Note.-The Hyattsville City Council is taking pains to preserve this interesting swamp.)

Comparison of Hard Surface and Soft Soil Impact Performance of a Crashworthy Composite Fuselage Concept

NASA Technical Reports Server (NTRS)

Sareen, Ashish K.; Sparks, Chad; Mullins, B. R., Jr.; Fasanella, Edwin; Jackson, Karen

2002-01-01

A comparison of the soft soil and hard surface impact performance of a crashworthy composite fuselage concept has been performed. Specifically, comparisons of the peak acceleration values, pulse duration, and onset rate at specific locations on the fuselage were evaluated. In a prior research program, the composite fuselage section was impacted at 25 feet per second onto concrete at the Impact Dynamics Research Facility (IDRF) at NASA Langley Research Center. A soft soil test was conducted at the same impact velocity as a part of the NRTC/RITA Crashworthy and Energy Absorbing Structures project. In addition to comparisons of soft soil and hard surface test results, an MSC. Dytran dynamic finite element model was developed to evaluate the test analysis correlation. In addition, modeling parameters and techniques affecting test analysis correlation are discussed. Once correlated, the analytical methodology will be used in follow-on work to evaluate the specific energy absorption of various subfloor concepts for improved crash protection during hard surface and soft soil impacts.

Post-fire fluxes and sources of carbon in previously burnt tropical swamp peatlands, Brunei

NASA Astrophysics Data System (ADS)

Lupascu, M.; Akhtar, H.; Smith, T. E. L.; Sukmaria binti Hj Sukri, R.

2017-12-01

Tropical peatlands hold about 15-19% of the global organic carbon (C) pool of which 77% in Southeast Asia. Nonetheless Southeast Asian peatlands have been exploited for timber and land for agriculture leading to rapid deforestation, extensive drainage and frequent fires. Direct C-emissions through peat combustion must be quantified to examine the impact of peat fires on global and regional C-budgets, however it is also essential to evaluate oxidative decomposition of peat after fires for a complete understanding of ecosystem-scale fire impact. This kind of investigation is necessary also to understand the effect of peat burning on peat decomposition, because burning effects on the belowground environment are variable, depending on burnt frequency and fire severity. After a fire, ecosystems act as a C-source for months-to-years as ecosystem-respiration (Reco) exceeds photosynthesis. Furthermore during fires, the surface peat with a higher proportion of the more modern rapidly-cycled C burns preferentially. The loss of the surface peat possibly can reduce oxidative soil CO2 emissions, as the deeper, older peat, has more recalcitrant compounds. However, CO2emissions from this old C pool are a net flux to the atmosphere compared to the modern C. Within this context, we are quantifying the magnitudes and patterns of ecosystem-atmosphere fluxes of carbon dioxide (CO2) and methane (CH4) through cavity-ring spectroscopy in different transects of an intact tropical peat swamp forest and in two degraded forest areas affected by two and six fires over the last 40 years in Brunei, on the island of Borneo. We are using natural tracers such as δ13C and 14C to investigate the age and sources (auto- and heterotrophic) of C contributing to Reco and we are continuously monitoring soil temperature and water table level. Preliminary data show a similar magnitude of CO2 efflux between the intact (5.3 µmol CO2 m-2 s-1) and burnt areas (6.4 µmol CO2 m-2 s-1), with higher soil temperature in the latter. Our results will give a deeper insight into the vulnerability of the C pool in tropical peat swamp forest after fire events and aim at improving terrestrial soil C budget.

Mapping Palm Swamp Wetland Ecosystems in the Peruvian Amazon: a Multi-Sensor Remote Sensing Approach

NASA Astrophysics Data System (ADS)

Podest, E.; McDonald, K. C.; Schroeder, R.; Pinto, N.; Zimmerman, R.; Horna, V.

2012-12-01

Wetland ecosystems are prevalent in the Amazon basin, especially in northern Peru. Of specific interest are palm swamp wetlands because they are characterized by constant surface inundation and moderate seasonal water level variation. This combination of constantly saturated soils and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, it is critical to develop methods to quantify their spatial extent and inundation state in order to assess their carbon dynamics. Spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We developed a remote sensing methodology using multi-sensor remote sensing data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR), Shuttle Radar Topography Mission (SRTM) DEM, and Landsat to derive maps at 100 meter resolution of palm swamp extent and inundation based on ground data collections; and combined active and passive microwave data from AMSR-E and QuikSCAT to derive inundation extent at 25 kilometer resolution on a weekly basis. We then compared information content and accuracy of the coarse resolution products relative to the high-resolution datasets. The synergistic combination of high and low resolution datasets allowed for characterization of palm swamps and assessment of their flooding status. This work has been undertaken partly within the framework of the JAXA ALOS Kyoto & Carbon Initiative. PALSAR data have been provided by JAXA. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Spatial analysis of Carbon-14 dynamics in a wetland ecosystem (Duke Swamp, Chalk River Laboratories, Canada).

PubMed

Yankovich, T L; King-Sharp, K J; Carr, J; Robertson, E; Killey, R W D; Beresford, N A; Wood, M D

2014-11-01

A detailed survey was conducted to quantify the spatial distribution of (14)C in Sphagnum moss and underlying soil collected in Duke Swamp. This wetland environment receives (14)C via groundwater pathways from a historic radioactive Waste Management Area (WMA) on Atomic Energy Canada Limited (AECL)'s Chalk River Laboratories (CRL) site. Trends in (14)C specific activities were evaluated with distance from the sampling location with the maximum (14)C specific activity (DSS-35), which was situated adjacent to the WMA and close to an area of groundwater discharge. Based on a spatial evaluation of the data, an east-to-west (14)C gradient was found, due to the influence of the WMA on (14)C specific activities in the swamp. In addition, it was possible to identify two groups of sites, each showing significant exponential declines with distance from the groundwater source area. One of the groups showed relatively more elevated (14)C specific activities at a given distance from source, likely due to their proximity to the WMA, the location of the sub-surface plume originating from the WMA, the presence of marsh and swamp habitat types, which facilitated (14)C transport to the atmosphere, and possibly, (14)C air dispersion patterns along the eastern edge of the swamp. The other group, which had lower (14)C specific activities at a given distance from the groundwater source area, included locations that were more distant from the WMA and the sub-surface plume, and contained fen habitat, which is known to act as barrier to groundwater flow. The findings suggest that proximity to source, groundwater flow patterns and habitat physical characteristics can play an important role in the dynamics of (14)C being carried by discharging groundwater into terrestrial and wetland environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Experimental study on the foundation of soft soil solidification formula based on the Design - Expert software search

NASA Astrophysics Data System (ADS)

Qian, Chaojun; Li, Dahua; Zhang, xian; Zhou, Dongqing; Zhang, Baoliang

2017-08-01

Xuan city + 1100 kv search for converter station in Anhui province, in the process of foundation treatment, there is a cloth with a large number of lacustrine soft soil can not reach the need of engineering construction, so we want to cure the soft soil. By combining ratio of blast furnace slag (GGBS), gypsum, exciting agent CaO as a main curing agent for combination of reinforcing soft soil, the indoor unconfined compressive strength test, the influence factors on blast furnace slag, exciting agent and dosage of gypsum as impact factors, response value is 7 d and 28 d unconfined compressive strength of solidified soil, the experimental method is the Box - Behnken. The results show that the 7 d gypsum and the interaction of the blast furnace slag is obvious; 28 d exciting agent and gypsum interaction is obvious. By the analysis plaster, CaO, GGBSIn 7 d optimal proportion is 3.71%, 3.62%, 12.18%, the actual strength of the solidified soil age 1479.33 kPa; 28 d optimal proportion was 4.08%, 4.50%, 11.6%, the actual strength of the solidified soil age 2936.78 kPa. In the soil and the water curing effect of GGBS solidified soil, thereby GGBS this is a kind of new solidification material that can be used as the engineering foundation treatment of soft soil stabilizer has a certain value.

Terrain Analysis Procedural Guide for Soil. Report Number 6 in the ETL Series on Guides for Army Terrain Analysts

DTIC Science & Technology

1981-02-01

01 T3 Swamp Pt. OH. CH. MH. OL T4 Peat Bog Pt T5 . - Peat Cuttings Pt T6 Cranberry Bog Pt. OH. CH. MH, OL T7 Rice holds Pt. OH, CH, MH, OL ’ ~Known...Commonly Associated Soils Landlorm/erc Climate Horizon USCS Symbol Coastal Plain unspecified unspecified OL. ML. CL. ML-CL, MH. Depressions CH, OH...total sample. SALINA A salt marsh or pond located adjacent to the sea, but not open to the sea. SALT PAN Any flat area or natural depression where water

Comparison of site preparation methods and stock types for artificial regeneration of oaks in bottomlands

Treesearch

Gordon W. Shaw; Daniel C. Dey; John Kabrick; Jennifer Grabner; Rose-Marie Muzika

2003-01-01

Regenerating oak in floodplains is problematic and current silvicultural methods are not always reliable. We are evaluating the field performance of a new nursery product, the RPM™ seedling, and the benefit of soil mounding and a cover crop of redtop grass to the survival and growth of pin oak and swamp white oak regeneration on former bottomland cropfields....

Xiphinema americanum as Affected by Soil Organic Matter and Porosity.

PubMed

Ponchillia, P E

1972-07-01

The effects of four soil types, soil porosity, particle size, and organic matter were tested on survival and migration of Xiphinema americanum. Survival and migration were significantly greater in silt loam than in clay loam and silty clay soils. Nematode numbers were significantly greater in softs planted with soybeans than in fallow softs. Nematode survival was greatest at the higher of two pore space levels in four softs. Migration of X. americanum through soft particle size fractions of 75-150, 150-250, 250-500, 500-700, and 700-1,000 mu was significantly greater in the middle three fractions, with the least occurring in the smallest fraction. Additions of muck to silt loam and loamy sand soils resulted in reductions in survival and migration of the nematode. The fulvic acid fraction of muck, extracted with sodium hydroxide, had a deleterious effect on nematode activity. I conclude that soils with small amounts of air-filled pore space, extremes in pore size, or high organic matter content are deleterious to the migration and survival of X. americanum, and that a naturally occurring toxin affecting this species may be present in native soft organic matter.

Using Landsat MSS data with soils information to identify wetland habitats

NASA Technical Reports Server (NTRS)

Ernst, C. L.; Hoffer, R. M.

1981-01-01

A previous study showed that certain fresh water wetland vegetation types can be spectrally separated when a maximum likelihood classification procedure is applied to Landsat spectral data. However, wetland and upland types which have similar vegetative life forms (e.g., upland hardwoods and hardwood swamps) are often confused because of spectral similarity. Therefore, the current investigation attempts to differentiate similar wetland and upland types by combining Landsat multispectral scanner (MSS) data with soils information. The Pigeon River area in northern Indiana used in the earlier study was also employed in this investigation. A layered classification algorithm which combined soils and spectral data was used to generate a wetland classification. The results of the spectral/soils wetland classification are compared to the previous classification that had been based on spectral data alone. The results indicate wetland habitat mapping can be improved by combining soils and other ancillary data with Landsat spectral data.

[Wetlands dominated by palms (Arecaceae), emphasis in those in the New World].

PubMed

Myers, Ronald L

2013-09-01

It is well known that most forests in humid tropical lowlands are species rich, and the popular view is that most species are represented by only a few individuals. Despite this common understanding of high richness and low species dominance, within humid tropical regions there are extensive forested ecosystems composed by only few species. These nearly monospecific forests usually occupy poorly drained soils and, except for the mangroves, are quite understudied. In this paper, I review the literature and my own field notes on more than three years studying the structure of palm swamps in Caribbean Costa Rica and Florida to describe some of the major vegetation associations in wetlands dominated by palm species in the Neotropical Region, although I also include some information about similar systems in the Old World Tropics. I mention the most abundant species that compose those palm dominated swamps and -whenever possible- describe forest structure, known distribution, and uses.

Temporal variability in methane fluxes from tropical peatlands within the Peruvian Amazon

NASA Astrophysics Data System (ADS)

Murphy, Wayne; Berrio, Juan Carlos; Boom, Arnoud; Page, Sue; Arn Teh, Yit

2016-04-01

Tropical peatlands are one of the largest soil carbon (C) reservoirs globally and play a significant role in modulating fluxes of C between the tropical biosphere and atmosphere. These C fluxes are of global importance because tropical wetlands are the single largest natural source of atmospheric methane (CH4); while land-use change and biomass burning also contribute to the growing global atmospheric carbon dioxide (CO2) burden. Amazonian peatlands play a potentially important role in regional and global atmospheric budgets of C because of their large extent. These ecosystems cover an estimated 150,000km2, which is roughly three-quarters the size of Indonesian peatlands; the world's most extensive and well-studied tropical peatlands. Here we report CH4 fluxes from a lowland tropical peatland in the Pastaza-Maranon foreland basin in Peru, one of the largest peatland complexes in the lowland Amazon Basin. Strong prolonged seasonal rainfall events and the annual Amazon River flood-pulse may lead to pronounced temporal variability in biogeochemical cycling and trace gas fluxes, and this study explored how CH4 fluxes varied among wet and dry season periods in a number of key vegetation types in this region. Sampling was concentrated in 3 of the most numerically-dominant vegetation types: Forested Swamp, Mixed Palm Swamp and Mauritia flexuosa-dominated Palm Swamp, with data collection occurring in both wet and dry seasons over a 2 year period from 2012-2014 (4 field campaigns in total). Overall mean CH4 fluxes from the Forested Swamp, Mixed Palm Swamp and Mauritia flexuosa-dominated Palm Swamp for the entire sampling period were 31.06 ± 3.42 mg CH4 - C m-2 d-1, 52.03 ± 16.05 mg CH4 - C m-2 d-1 and 36.68 ± 4.32 mg CH4 - C m-2 d-1. CH4 emissions, when averaged across the entire dataset, did not differ significantly among habitats. However, when CH4 emissions were aggregated by season, the Mixed Palm Swamp showed a significantly different emissions from all other habitats (Fischers LSD, P<0.0001). All of the vegetation types showed pronounced seasonality in CH4 fluxes. Mean dry and wet season fluxes for the Forested Swamp were 18.82 ± 2.61 mg CH4 - C m-2 d-1 and 60.42 ± 9.11 mg CH4 - C m-2 d-1; 85.51 ± 26.36 mg CH4 - C m-2 d-1 and 5.15 ± 2.73 mg CH4 - C m-2 d-1 for the Mixed Palm Swamp; and 25.54 ± 2.9 mg CH4 - C m-2 d-1 and 53.36 ± 9.78 mg CH4 - C m-2 d-1 for the Mauritia flexuosa-dominated Palm Swamp. Dry season fluxes did not differ from each other between years. In contrast, wet season fluxes showed significant differences between years, with CH4 emissions in the 2012 wet season more than double the emissions from the 2014 year. These observed differences in CH4 emissions during different seasons suggest that seasonal variability in water availability and flooding is a key control on CH4 emissions from Amazonian peatlands.

Drawbar Pull

DTIC Science & Technology

2017-01-26

Includes procedures for hard surface, soil , and water tests. Discusses vehicle preparation, instrumentation method of computing results, data reduction...and amphibious vehicles. 15. SUBJECT TERMS Bollard pull Soft- soil mobility Drawbar pull Vehicle, amphibious Drawbar horsepower Vehicle...4.3 Drawbar Pull in Soft Soil ................................................. 8 4.4 Amphibious Vehicle Tests (Drawbar Pull in Water and Bollard Pull

Historical Geography of the Upper Tombigbee Valley.

DTIC Science & Technology

1982-05-01

of the trees, shrubs and vines of Alabama with their economic properties and local distribution. University of Alabama, Tuscaloosa. *1943 Forests of...elements in common with the prairies of the Midwest (Clark, 1972). In areas in which the soil is relatively deep a rich forest develops similar to that...common in the forest include swamp privet, red bay, water elm, American elm, cabbage palm, sugarberry, and rattan vine . The combination of dense

A carbon balance model for the great dismal swamp ecosystem

USGS Publications Warehouse

Sleeter, Rachel; Sleeter, Benjamin M.; Williams, Brianna; Hogan, Dianna; Hawbaker, Todd J.; Zhu, Zhiliang

2017-01-01

BackgroundCarbon storage potential has become an important consideration for land management and planning in the United States. The ability to assess ecosystem carbon balance can help land managers understand the benefits and tradeoffs between different management strategies. This paper demonstrates an application of the Land Use and Carbon Scenario Simulator (LUCAS) model developed for local-scale land management at the Great Dismal Swamp National Wildlife Refuge. We estimate the net ecosystem carbon balance by considering past ecosystem disturbances resulting from storm damage, fire, and land management actions including hydrologic inundation, vegetation clearing, and replanting.ResultsWe modeled the annual ecosystem carbon stock and flow rates for the 30-year historic time period of 1985–2015, using age-structured forest growth curves and known data for disturbance events and management activities. The 30-year total net ecosystem production was estimated to be a net sink of 0.97 Tg C. When a hurricane and six historic fire events were considered in the simulation, the Great Dismal Swamp became a net source of 0.89 Tg C. The cumulative above and below-ground carbon loss estimated from the South One and Lateral West fire events totaled 1.70 Tg C, while management activities removed an additional 0.01 Tg C. The carbon loss in below-ground biomass alone totaled 1.38 Tg C, with the balance (0.31 Tg C) coming from above-ground biomass and detritus.ConclusionsNatural disturbances substantially impact net ecosystem carbon balance in the Great Dismal Swamp. Through alternative management actions such as re-wetting, below-ground biomass loss may have been avoided, resulting in the added carbon storage capacity of 1.38 Tg. Based on two model assumptions used to simulate the peat system, (a burn scar totaling 70 cm in depth, and the soil carbon accumulation rate of 0.36 t C/ha−1/year−1 for Atlantic white cedar), the total soil carbon loss from the South One and Lateral West fires would take approximately 1740 years to re-amass. Due to the impractical time horizon this presents for land managers, this particular loss is considered permanent. Going forward, the baseline carbon stock and flow parameters presented here will be used as reference conditions to model future scenarios of land management and disturbance.

A carbon balance model for the great dismal swamp ecosystem.

PubMed

Sleeter, Rachel; Sleeter, Benjamin M; Williams, Brianna; Hogan, Dianna; Hawbaker, Todd; Zhu, Zhiliang

2017-12-01

Carbon storage potential has become an important consideration for land management and planning in the United States. The ability to assess ecosystem carbon balance can help land managers understand the benefits and tradeoffs between different management strategies. This paper demonstrates an application of the Land Use and Carbon Scenario Simulator (LUCAS) model developed for local-scale land management at the Great Dismal Swamp National Wildlife Refuge. We estimate the net ecosystem carbon balance by considering past ecosystem disturbances resulting from storm damage, fire, and land management actions including hydrologic inundation, vegetation clearing, and replanting. We modeled the annual ecosystem carbon stock and flow rates for the 30-year historic time period of 1985-2015, using age-structured forest growth curves and known data for disturbance events and management activities. The 30-year total net ecosystem production was estimated to be a net sink of 0.97 Tg C. When a hurricane and six historic fire events were considered in the simulation, the Great Dismal Swamp became a net source of 0.89 Tg C. The cumulative above and below-ground carbon loss estimated from the South One and Lateral West fire events totaled 1.70 Tg C, while management activities removed an additional 0.01 Tg C. The carbon loss in below-ground biomass alone totaled 1.38 Tg C, with the balance (0.31 Tg C) coming from above-ground biomass and detritus. Natural disturbances substantially impact net ecosystem carbon balance in the Great Dismal Swamp. Through alternative management actions such as re-wetting, below-ground biomass loss may have been avoided, resulting in the added carbon storage capacity of 1.38 Tg. Based on two model assumptions used to simulate the peat system, (a burn scar totaling 70 cm in depth, and the soil carbon accumulation rate of 0.36 t C/ha -1 /year -1 for Atlantic white cedar), the total soil carbon loss from the South One and Lateral West fires would take approximately 1740 years to re-amass. Due to the impractical time horizon this presents for land managers, this particular loss is considered permanent. Going forward, the baseline carbon stock and flow parameters presented here will be used as reference conditions to model future scenarios of land management and disturbance.

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands.

PubMed

Turetsky, Merritt R; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B; Crill, Patrick; Hornibrook, Ed R C; Minkkinen, Kari; Moore, Tim R; Myers-Smith, Isla H; Nykänen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J Michael; White, Jeffrey R; Wickland, Kimberly P; Wilmking, Martin

2014-07-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release. © 2014 John Wiley & Sons Ltd.

A synthesis of methane emissions from 71 northern, temperate, and subtropical wetlands

USGS Publications Warehouse

Turetsky, Merritt R.; Kotowska, Agnieszka; Bubier, Jill; Dise, Nancy B.; Crill, Patrick; Hornibrook, Ed R.C.; Minkkinen, Kari; Moore, Tim R.; Myers-Smith, Isla H.; Nykanen, Hannu; Olefeldt, David; Rinne, Janne; Saarnio, Sanna; Shurpali, Narasinha; Tuittila, Eeva-Stiina; Waddington, J. Michael; White, Jeffrey R.; Wickland, Kimberly P.; Wilmking, Martin

2014-01-01

Wetlands are the largest natural source of atmospheric methane. Here, we assess controls on methane flux using a database of approximately 19 000 instantaneous measurements from 71 wetland sites located across subtropical, temperate, and northern high latitude regions. Our analyses confirm general controls on wetland methane emissions from soil temperature, water table, and vegetation, but also show that these relationships are modified depending on wetland type (bog, fen, or swamp), region (subarctic to temperate), and disturbance. Fen methane flux was more sensitive to vegetation and less sensitive to temperature than bog or swamp fluxes. The optimal water table for methane flux was consistently below the peat surface in bogs, close to the peat surface in poor fens, and above the peat surface in rich fens. However, the largest flux in bogs occurred when dry 30-day averaged antecedent conditions were followed by wet conditions, while in fens and swamps, the largest flux occurred when both 30-day averaged antecedent and current conditions were wet. Drained wetlands exhibited distinct characteristics, e.g. the absence of large flux following wet and warm conditions, suggesting that the same functional relationships between methane flux and environmental conditions cannot be used across pristine and disturbed wetlands. Together, our results suggest that water table and temperature are dominant controls on methane flux in pristine bogs and swamps, while other processes, such as vascular transport in pristine fens, have the potential to partially override the effect of these controls in other wetland types. Because wetland types vary in methane emissions and have distinct controls, these ecosystems need to be considered separately to yield reliable estimates of global wetland methane release.

Carbon-14 Specific Activity Model Validation for Biota in Wetland Environments

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

Yankovich, T.L.; Sharp, K.J.; Benz, M.L.

2008-01-15

In many cases, contaminants, such as radionuclides, can show highly localized spatial distributions in natural systems. Therefore, a key question for environmental assessment and monitoring becomes, how can these localized distributions of contaminants in the environment lead to organism exposure, and ultimately, the potential for effects to receptor biota? To address this question, an important first step is to conduct field surveys at sites of interest to map out the spatial distribution and extent of contaminants in areas that are being occupied and utilized by resident receptor biota. Work can then be conducted to establish predictive relationships between contaminant concentrationsmore » in biota tissues and those in environmental media with which biota interact, to gain an understanding of how representative ambient contaminant concentrations are of biota exposure. The objectives of this study were: - To conduct a field survey in a wetland ecosystem to characterize the spatial distribution of carbon- 14 ({sup 14}C), a radionuclide with dynamics in natural systems that can be described using a specific activity model; and - To determine whether {sup 14}C concentrations in environmental media reflect those measured in tissues of resident flora and fauna. A detailed field campaign was carried out in summer 2001 to characterize the spatial distribution and areal coverage of {sup 14}C in Duke Swamp, a wetland ecosystem on Atomic Energy of Canada Limited (AECL)'s Chalk River Laboratories (CRL) site that receives {sup 14}C through releases from an up-gradient Waste Management Area (WMA), primarily through groundwater influx. Sampling of surface vegetation (dominantly comprised of Sphagnum moss) was conducted at a total of 69 locations, with complementary sampling of air, soil, fungi, aerial insects, ground-dwelling insects, amphibians, small mammals and snakes being carried out at a subset of five locations with varying {sup 14}C concentrations. Concentrations of {sup 14}C in resident Duke Swamp biota were compared to levels measured in environmental media (including moss, soil and air) to determine whether concentrations in such media reflect animal exposure, for application in routine environmental monitoring programs on the CRL site. In general, for most types of receptor animals, {sup 14}C specific activities were found to be similar to or less than those measured in air, soil and surface vegetation at all locations sampled, suggesting that in most cases, estimates of {sup 14}C levels in animals could either be realistically or conservatively predicted based on the values measured in environmental media. In the case of fungi, receptor-to-media {sup 14}C specific activity ratios fell between 0.04 and 0.23 relative to air, between 0.03 and 0.70 relative to soil, and between 0.078 and 0.31 relative to moss. Small mammal specific activities also generally fell well below those that would be predicted based on specific activities measured in environmental media, with ratios ranging from 0.11 to 0.36 relative to air, from 0.17 to 0.85 relative to soil and from 0.21 to 0.58 relative to moss. Similar ratios were also established for snakes; however, a notable exception occurred for amphibians, a type of animal that tends to spend relatively more time in aquatic environments than the other species tested. In the case of Duke Swamp amphibians, animal-to-air {sup 14}C specific activity ratios ranged from 0.40 to 2.3, animal-to-soil ratios ranged from 0.81 to 3.4 and animal-to-moss ratios ranged from 1.5 to 2.4. These higher {sup 14}C levels in amphibians relative to the environmental media may be due to increased {sup 14}C exposure of aquatic or amphibious animals that occupy systems receiving inputs via groundwater. In such systems, {sup 14}C is incorporated in aquatic plants and animals, and later transferred to higher predatory species, such as amphibians, that consume them. Therefore, with the exception of amphibians and other aquatic receptor species, it is reasonable to estimate concentrations of {sup 14}C in receptor biota in wetland environments like Duke Swamp at CRL, based on measurements of {sup 14}C in environmental media, including air, soil and surface vegetation. In the case of Duke Swamp amphibians, environmental media concentrations could still be roughly predicted if they are multiplied by a 4-fold correction factor. In addition, our study findings also confirm that in cases where elevated {sup 14}C levels are highly localized, elevated exposures to resident biota are also highly localized. Such information is critical to the development of cost-effective environmental monitoring programs that are protective of nonhuman biota, while reducing the need to capture and euthanize animals during routine monitoring.« less

Dynamic deformation of soft soil media: Experimental studies and mathematical modeling

NASA Astrophysics Data System (ADS)

Balandin, V. V.; Bragov, A. M.; Igumnov, L. A.; Konstantinov, A. Yu.; Kotov, V. L.; Lomunov, A. K.

2015-05-01

A complex experimental-theoretical approach to studying the problem of high-rate strain of soft soil media is presented. This approach combines the following contemporary methods of dynamical tests: the modified Hopkinson-Kolsky method applied tomedium specimens contained in holders and the method of plane wave shock experiments. The following dynamic characteristics of sand soils are obtained: shock adiabatic curves, bulk compressibility curves, and shear resistance curves. The obtained experimental data are used to study the high-rate strain process in the system of a split pressure bar, and the constitutive relations of Grigoryan's mathematical model of soft soil medium are verified by comparing the results of computational and natural test experiments of impact and penetration.

Late Holocene vegetation and fire dynamics from a savanna-forest ecotone in Roraima state, northern Brazilian Amazon

NASA Astrophysics Data System (ADS)

da Silva Meneses, Maria Ecilene Nunes; da Costa, Marcondes Lima; Behling, Hermann

2013-03-01

Two sediment cores from Mauritia flexuosa palm swamps have been studied by pollen and charcoal analysis. The cores Fazenda Cigana (FC) and Terra Indígena Aningal (TIA) were taken from a savanna-forest ecotone area in the Roraima State, northern Brazilian Amazon. Based on 5 radiocarbon dates, these records allow the reconstruction of the vegetation fire and climate dynamics during the past 1550 years. At the FC site was recorded a higher proportion of forest cover, suggesting local wetter climatic conditions favorable for forest expansion, especially by gallery forests, between 1550 and 1400 cal yr BP. Stands of M. flexuosa started to establish on the site indicating sufficient soil moisture. From 1400 to 1050 cal yr BP, forest cover retreated while savanna, and the Mauritia palm swamp expanded considerably. The FC site was marked by savanna and Mauritia cover with a slight increase of forest between ca. 1050 and 900 cal yr BP. From 900 to 300 cal yr BP the savanna and palm swamp taxa became dominant and the forest area decreased. At the TIA site the savanna cover was dominant between 1200 and 1000 cal yr BP. From 1000 to 700 forest expanded while savanna and Mauritia palm swamp reduced. Between 700 and 300 cal yr BP savanna and Mauritia palm swamp increased and forest area decreased. The high amount of charred particles found in the sediments, indicate fires with a marked increase between 1400 to 1000 cal yr BP (FC site) and 700 to 300 cal yr BP (TIA site), and probably caused the retreat of forest cover during these two time intervals. The relatively lower fire activity after 300 cal yr BP until present-day favored the increase of forested area at both TIA and FC sites. The arrival of the European settler and the subsequent introduction of cattle, is suggested as the main reason for the decrease of fire in the study region. The results point the fire caused by indigenous people as the principal controlling factor for forest and savanna dynamics during the past 1550 years.

Prediction of embankment settlement over soft soils.

DOT National Transportation Integrated Search

2009-06-01

The objective of this project was to review and verify the current design procedures used by TxDOT : to estimate the total and rate of consolidation settlement in embankments constructed on soft soils. Methods : to improve the settlement predictions ...

Variations in Soft Soil of Troy False Color

NASA Image and Video Library

2009-06-25

The soft soil exposed when wheels of NASA Mars Exploration Rover Spirit dug into a patch of ground dubbed Troy exhibit variations in hue visible in this image, in which the colors have been stretched to emphasize the differences.

Integral abutment bridge for Louisiana's soft and stiff soils.

DOT National Transportation Integrated Search

2008-02-01

The proposed research will be to field instrument, monitor, and analyze the design and construction of full integral abutment bridges for Louisianas soft and stiff soil conditions. Comparison of results will be submitted to the Louisiana Departmen...

Wetland and water supply

USGS Publications Warehouse

Baker, John Augustus

1960-01-01

The Geological Survey has received numerous inquiries about the effects of proposed changes in the wetland environment. The nature of the inquiries suggests a general confusion in the public mind as to wetland values and an increasing concern by the public with the need for facts as a basis for sound decisions when public action is required. Perhaps the largest gap in our knowledge is in regard to the role played by the wetland in the natural water scheme. Specialists in such fields as agriculture and conservation have studied the wetland in relation to its special uses and values for farming and as a habitat for fish and wildlife. However, except as studied incidentally by these specialists, the role of the wetland with respect to water has been largely neglected. This facet of the wetland problem is of direct concern to the Geological Survey. We commonly speak of water in terms of its place in the hydrologic environment---as, for example, surface water or ground water. These terms imply that water can be neatly pigeonholed. With respect to the wetland environment nothing can be further from the truth. In fact, one objective of this discussion is to demonstrate that for the wetland environment surface water, ground water, and soil water cannot be separated realistically, but are closely interrelated and must be studied together. It should be noted that this statement holds true for the hydrologic environment in general, and that the wetland environment is by no means unique in this respect. Our second and principal objective is to identify some of the problems that must be studied in order to clarify the role of the wetland in relation to water supply. We have chosen to approach these objectives by briefly describing one area for which we have some information, and by using this example to point out some of the problems that need study. First, however, let us define what we, as geohydrologists, mean by wetland and briefly consider wetland classifications. For our purpose wetlands are land areas that are covered with shallow water or subjected to intermittent flooding and subsequent slow drainage, and which generally are characterized by an accumulation of organic matter hereafter termed swamp deposits.' These wetlands may be classified in a number of different ways depending on the purpose of the classifier. For example, the Fish and Wildlife Service classifies wetlands into 20 different types based on water quality (fresh or salty), drainage, and vegetation. At the risk of some oversimplification we might consider 4 types of wetland from the standpoint of hydrology: (1) fresh-water swamps in which the swamp deposits are underlain by glacial till or bedrock; (2)fresh-water swamps in which the swamp deposits are underlain by marine or lacustrine clay and silt; (3) fresh-water swamps in which the swamp deposits are underlain by glacial outwash or alluvium consisting mostly of sand or sand and gravel; and (4) salt .marshes and salt meadows. The three fresh-water types of wetland are of interest with respect to water supply, and of these, the type in which swamp deposits are underlain by glacial outwash is of particular interest in New England. In the Ipswich River basin above the Geological Survey gaging station at South Middleton, Mass., is an area of 44 square miles which forms the headwaters section of the basin. The relief of the area is low. About half the area consists of hills mostly underlain by bedrock but mantled by a thin layer of glacial till. The other half consists Of lowlands---including swamps, low terraces and plains---underlain by glacial outwash, Swampland, used hereafter as a synonym for wetland, forms about a fourth of the area. Some of the swamps occupy depressions in the till blanket and are situated at somewhat higher levels than the lowlands. The largest swamps, however, border the Ipswich River and its tributaries. Here the swamp deposits, which consist of muck and peat mixed with s

Risk assessment framework on time impact: Infrastructure projects in soft soil during construction stage

NASA Astrophysics Data System (ADS)

Low, W. W.; Wong, K. S.; Lee, J. L.

2018-04-01

With the growth of economy and population, there is an increase in infrastructure construction projects. As such, it is unavoidable to have construction projects on soft soil. Without proper risk management plan, construction projects are vulnerable to different types of risks which will have negative impact on project’s time, cost and quality. Literature review showed that little or none of the research is focused on the risk assessment on the infrastructure project in soft soil. Hence, the aim of this research is to propose a risk assessment framework in infrastructure projects in soft soil during the construction stage. This research was focused on the impact of risks on project time and internal risk factors. The research method was Analytical Hierarchy Process and the sample population was experienced industry experts who have experience in infrastructure projects. Analysis was completed and result showed that for internal factors, the five most significant risks on time element are lack of special equipment, potential contractual disputes and claims, shortage of skilled workers, delay/lack of materials supply, and insolvency of contractor/sub-contractor. Results indicated that resources risk factor play a critical role on project time frame in infrastructure projects in soft soil during the construction stage.

Applicability of recycled aggregates in concrete piles for soft soil improvement.

PubMed

Medeiros-Junior, Ronaldo A; Balestra, Carlos Et; Lima, Maryangela G

2017-01-01

The expressive generation of construction and demolition waste is stimulating several studies for reusing this material. The improvement of soft soils by concrete compaction piles has been widely applied for 40 years in some Brazilian cities. This technique is used to improve the bearing capacity of soft soils, allowing executing shallow foundations instead of deep foundations. The compaction piles use a high volume of material. This article explored the possibility of using recycled aggregates from construction waste to replace the natural aggregates in order to improve the bearing capacity of the soft soil, regarding its compressive strength. Construction wastes from different stages of a construction were used in order to make samples of concrete with recycled aggregates. The strength of concretes with natural aggregates was compared with the strength of concretes with recycled (fine and coarse) aggregates. Results show that all samples met the minimum compressive strength specified for compaction piles used to improve the bearing capacity of soft soils. The concrete with recycled aggregate from the structural stage had even higher resistances than the concrete with natural aggregates. This behaviour was attributed to the large amount of cementitious materials in the composition of this type of concrete. It was also observed that concrete with recycled fine aggregate has a superior resistance to concrete with recycled coarse aggregate.

Analysis of water and nitrogen use efficiency for maize (Zea mays L.) grown on soft rock and sand compound soil.

PubMed

Wang, Huanyuan; Han, Jichang; Tong, Wei; Cheng, Jie; Zhang, Haiou

2017-06-01

Maize was grown on compound soils constituted from mixtures of soft rock and sand at different ratios, and water use efficiency (WUE), nitrogen use efficiency (NUE) and fertilizer nitrogen use efficiency (FNUE) were quantified. The data were used to assist in designing strategies for optimizing water and nitrogen management practices for maize on the substrates used. Maize was sown in composite soil prepared at three ratios of soft rock and sand (1:1, 1:2 and 1:5 v/v) in Mu Us Sandy Land, Yuyang district, Yulin city, China. Yields, amount of drainage, nitrogen (N) leaching, WUE and NUE were calculated. Then a water and nitrogen management model (WNMM) was calibrated and validated. No significant difference in evapotranspiration of maize was found among compound soils with soft rock/sand ratios of 1:1, 1:2 and 1:5, while water drainage increased significantly with increasing soft rock/sand ratio. WUE increased to 1.30 kg m -3 in compound soil with 1:2 soft rock/sand ratio. Nitrogen leaching and ammonia volatilization were the main reason for nitrogen loss, and N reduction mainly relied on crop uptake. NUE and FNUE could reach 33.1 and 24.9 kg kg -1 N respectively. Water drainage and nitrogen leaching occurred mostly during heavy rainfall or irrigation. Through a scenario analysis of different rainfall types, water and fertilizer management systems were formulated each year. This study shows that soft rock plays a key role in improving the WUE, NUE and FNUE of maize. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Soil settlement analysis in soft soil by using preloading system and prefabricated vertical draining runway of Kualanamu Airport

NASA Astrophysics Data System (ADS)

Roesyanto; Iskandar, R.; Silalahi, S. A.; Fadliansyah

2018-02-01

The method of soil improvement, using the combination of prefabricated vertical drain (PVD) and preloading, was used to accelerate the process of consolidation and the consolidation settlement in the runway of Kualanamu International Airport, which was constructed on the soft soil sediment like silty clay. In this research, the investigated area was the runway of Kualanamu International Airport zone I which had 11 meter-thickness of soft soil. Geotechnic instruments surveyed was settlement plate. Monitoring was done toward the behavior of landfill such as basic soil settlement. The result were compared with the analysis of finite element method of full scale in Mohr-Coulomb model by verifying the vertical drain of asymmetric unit cell and equivalent plane strain unit cell condition. The results of the research showed that there were an interesting behavior between the data in field observation and finite element of Mohr-Coulomb model. It was also found that the result of soil settlement of finite element method of Mohr-Coulomb model was closed to the result of settlement plate monitoring.

Strength and Stiffness Development in Soft Soils: A FESEM aided Soil Microstructure Viewpoint

NASA Astrophysics Data System (ADS)

Wijeyesekera, D. C.; Ho, M. H.; Bai, X.; Bakar, I.

2016-07-01

This paper opens with an overview of the debatable definition of soft soil that goes beyond a (CH) organic / inorganic clay and OH peat to include weakly cemented periglacial deposits of loess and alike. It then outlines the findings obtained from stiffness test on cement-stabilised soft clay. The findings are complemented with a microstructure viewpoint obtained using field emission scanning electron microscope (FESEM). Research also comprised of making cylindrical stabilised clay samples, prepared in the laboratory with various rubber chips contents and cement, and then aged for 28 days. The samples were then subjected to unconfined compressive strength (UCS) test and observations were also made of its microstructure using the FESEM. The impact of the soil microstructure on the stiffness result was studied both with the stabilized soil and also of some of the natural undisturbed loess soils. Sustainability aspect and the potential of the use of rubber chips and sand as additives to cement stabilisation are also discussed. The overall test results indicated that rubber chips and sand contributed to the improvement in unconfined compressive strength (qu). The derogatory influence of moisture on the stiffness of the stabilised clay was studied simultaneously. SEM micrographs are presented that show bonding of cement, rubber chips/ sand and soft clay, granular units and aggregated / agglomerated units in loess. The paper concludes with observations on the dependence of soil microstructure on the soil strength and deformability and even collapsibility of the loess. Current practices adopted as engineering solutions to these challenging soils are outlined.

Toxicity of 5% rotenone to nonindigenous Asian swamp eels

USGS Publications Warehouse

Schofield, P.J.; Nico, L.G.

2007-01-01

Our primary goal was to determine whether rotenone would be a useful control against introduced populations of Asian swamp eels (family Synbranchidae, genus Monopterus). We report the results of a laboratory experiment comparing the efficacy of various rotenone concentrations (1, 2, 4, and 8 mg of 5% liquid rotenone/L of water) in killing nonindigenous swamp eels of various sizes (1-350 g) from the three known Florida populations. Although most small swamp eels were killed at concentrations of 2 and 4 mg/L. 100% mortality of adult swamp eels was achieved only at 8 mg/L. We conclude that the effective use of rotenone to control established Florida swamp eel populations would be difficult, based on the relatively high concentration of rotenone needed to kill swamp eels; the complexity of the swamp eel's habitat; and our observations of the species' habitat use and behavior, including its widespread distribution and life history characteristics (e.g., burrowing and overland movement) that enhance its invasion and survival in multiple environments. Nevertheless, control of swamp eels may be achieved in certain situations. A combination of rotenone and electroshocking may be an effective way to eradicate swamp eels from small water bodies and to control populations in larger habitats. However, we are cautious in this recommendation and provide details related to the technical aspects of this type of strategy and caveats related to the toxicity of the chemical.

Water Sources of Temperate Upland Swamps of Eastern Australia. Implications for Groundwater Management and Climate Change.

NASA Astrophysics Data System (ADS)

Cowley, K.; Fryirs, K.; Chisari, R.; Hose, G. C.

2016-12-01

Temperate upland swamps in Eastern Australia are endangered ecological communities under State and National legislation. They occur in headwaters of low order streams on low relief plateaus, providing base flow to streams that contribute to Sydney's major drinking water supplies that support some 4.5 million people. The swamps are also subject to aquifer interference activities from long wall mining and groundwater extraction, and are threatened by a changing climate. It is therefore critical that we understand their water source, storage capacity and residence times. We collected seasonal water samples from perched swamp aquifers in two highland regions of Eastern Australia for analysis of hydrogen and oxygen isotopes and compared them with rainwater, surface water and deeper groundwater to determine whether the swamps were primarily rainwater or groundwater fed. 222Rn was used as an environmental tracer to calculate residence times and relative groundwater/surface water ratios. We found over 60% of the swamps were sensitive to evaporation which has implications for swamp health in a warmer climate. Over a third of water from the perched swamp aquifer is derived from deeper sandstone aquifers with residence times of between 1.2 and 15 days. This swamp-groundwater connectivity means that mining activities or large-scale groundwater extraction could interfere with a significant component of the swamps' water source, its water storage capacity and downstream contributions to Sydney's drinking water supplies.

Sweat Farm Road Fire in Georgia

NASA Technical Reports Server (NTRS)

2007-01-01

Dense plumes of blue-white smoke billowed from the Sweat Farm Road Fire in southern Georgia on April 19, 2007, when the Landsat 5 satellite captured this detailed image. The fire started on April 16, when a tree fell on a power line and, fanned by strong winds, quickly exploded into a major fire. By April 19, the fire had forced officials to close several roads, including U.S. Highway 1, and to evacuate hundreds of people from the perimeter of the city of Waycross, the silver cluster along the top edge of the image. The nearness of the fire is evident in the dark brown, charred land just south of the city. The active fire front is along the south edge of the burned area, where the flames are eating into the dark green hardwood forests, pine plantations, and shrubs in Okefenokee Swamp. Because of the difficult terrain, the fire and the adjoining Big Turnaround Complex fire are expected to burn until significant rain falls, said the morning report issued by the Southern Area Coordination Center on May 4. 'In the long term, the burning of the swamp will ultimately benefit the swamp wilderness habitat, which is a fire-dependent ecosystem,' said a press release issued from the Okefenokee National Wildlife Refuge on May 4. Such ecosystems require fire to remain healthy. In the case of southern pine forests, many pine species need fire to remove litter from the ground and release soil nutrients so that new seedlings can grow.

Developing ecologically based PCB, pesticide, and metal remedial goals for an impacted northeast wooded swamp

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

Rury, P.M.; Turton, D.J.

Historically, remedial goals at hazardous waste sites have been developed based on human health risk estimates. As the disciplines of remedial investigation, risk assessment, and remedial design have evolved, there has been a shift toward the development of remedial goals that are protective of both human health and the environment. This has increased the need for sound quantitative ecological risk methodologies from which to derive ecologically protective remedial goals. The foundation of many ecological risk assessment models is the bioconcentration or bioaccumulation factor that estimates the partitioning of the compound of concern between the media (e.g., water, soil, or food)more » and the organism. Simple dietary food-chain models are then used to estimate the dose and resulting risk to higher trophic levels. For a Superfund site that encompassed a northeastern wooded swamp, a PCB pesticide and metal uptake and toxicity study was conducted on the earthworm commonly known as the red wiggler (Eisenea foetida). The study resulted in site-specific sediment to earthworm bioconcentration factors for PCBs and a range of pesticides and metals. In addition, largemouth bass and yellow perch were collected from an impacted pond to identify PCB and pesticide concentrations in mink (Mustela vison) prey. Utilizing the empirical data and site-specific bioconcentration factors in food-chain models, potential risks to the American woodcock (Scolopax minor) and mink were assessed, and ecologically protective PCB, pesticide, and metal remedial goals for the sediments of the wooded swamp were developed.« less

Recycling of phenolic compounds in Borneo's tropical peat swamp forests.

PubMed

Yule, Catherine M; Lim, Yau Yan; Lim, Tse Yuen

2018-02-07

Tropical peat swamp forests (TPSF) are globally significant carbon stores, sequestering carbon mainly as phenolic polymers and phenolic compounds (particularly as lignin and its derivatives) in peat layers, in plants, and in the acidic blackwaters. Previous studies show that TPSF plants have particularly high levels of phenolic compounds which inhibit the decomposition of organic matter and thus promote peat accumulation. The studies of phenolic compounds are thus crucial to further understand how TPSF function with respect to carbon sequestration. Here we present a study of cycling of phenolic compounds in five forests in Borneo differing in flooding and acidity, leaching of phenolic compounds from senescent Macaranga pruinosa leaves, and absorption of phenolics by M. pruinosa seedlings. The results of the study show that total phenolic content (TPC) in soil and leaves of three species of Macaranga were highest in TPSF followed by freshwater swamp forest and flooded limestone forest, then dry land sites. Highest TPC values were associated with acidity (in TPSF) and waterlogging (in flooded forests). Moreover, phenolic compounds are rapidly leached from fallen senescent leaves, and could be reabsorbed by tree roots and converted into more complex phenolics within the leaves. Extreme conditions-waterlogging and acidity-may facilitate uptake and synthesis of protective phenolic compounds which are essential for impeded decomposition of organic matter in TPSF. Conversely, the ongoing drainage and degradation of TPSF, particularly for conversion to oil palm plantations, reverses the conditions necessary for peat accretion and carbon sequestration.

Off-Road Soft Soil Tire Model Development and Experimental Testing

DTIC Science & Technology

2011-06-29

Eduardo Pinto 2 , Mr. Scott Naranjo 3 , Dr. Paramsothy Jayakumar 4 , Dr. Archie Andonian 5 , Dr. Dave Hubbell 6 , Dr. Brant Ross 7 1Virginia...The effect of soil charac- teristics on the tire dynamics will be studied. Validation against data collected from full vehicle testing is included in...the proposed future work. Keywords: tire model, soft soil, terramechanics, vehicle dynamics , indoor testing 1 Introduction The goal of this paper is

Geostatistical modeling of the spatial distribution of sediment oxygen demand within a Coastal Plain blackwater watershed

PubMed Central

Todd, M. Jason; Lowrance, R. Richard; Goovaerts, Pierre; Vellidis, George; Pringle, Catherine M.

2010-01-01

Blackwater streams are found throughout the Coastal Plain of the southeastern United States and are characterized by a series of instream floodplain swamps that play a critical role in determining the water quality of these systems. Within the state of Georgia, many of these streams are listed in violation of the state’s dissolved oxygen (DO) standard. Previous work has shown that sediment oxygen demand (SOD) is elevated in instream floodplain swamps and due to these areas of intense oxygen demand, these locations play a major role in determining the oxygen balance of the watershed as a whole. This work also showed SOD rates to be positively correlated with the concentration of total organic carbon. This study builds on previous work by using geostatistics and Sequential Gaussian Simulation to investigate the patchiness and distribution of total organic carbon (TOC) at the reach scale. This was achieved by interpolating TOC observations and simulated SOD rates based on a linear regression. Additionally, this study identifies areas within the stream system prone to high SOD at representative 3rd and 5th order locations. Results show that SOD was spatially correlated with the differences in distribution of TOC at both locations and that these differences in distribution are likely a result of the differing hydrologic regime and watershed position. Mapping of floodplain soils at the watershed scale shows that areas of organic sediment are widespread and become more prevalent in higher order streams. DO dynamics within blackwater systems are a complicated mix of natural and anthropogenic influences, but this paper illustrates the importance of instream swamps in enhancing SOD at the watershed scale. Moreover, our study illustrates the influence of instream swamps on oxygen demand while providing support that many of these systems are naturally low in DO. PMID:20938491

Effects of harvesting cypress swamps on water quality and quantity

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

Ewel, K.C.

1985-09-01

The responses of cypress swamps to a spectrum of harvest techniques are being studied in the Withlacoochee State Forest, Hernando County, Florida. Among the 11 swamps in the study area, four contain plots that were harvested experimentally in 1984. Stand improvement cuts were made in plots in two large swamps. Measurements of tree biomass were made in all but two of the large swamps. The swamps were surveyed for cone production in the fall and regeneration in the spring. However, coppice was produced in all the harvested plots. These preliminary results suggest that coppice production may be a dependable regenerationmore » method, although it may not be desirable for stand improvement cuts and thinning. Evapotranspiration from three cypress swamps averaged 79 cm over a 3-year period. The purpose of this project was to determine specific impacts of harvesting on water quality and water loss rates in the study areas.« less

Baldcypress swamp management and climate change

USGS Publications Warehouse

Middleton, Beth A.

2006-01-01

In the future, climates may become warmer and drier in the southeastern United States; as a result, the range of baldcypress (Taxodium distichum) swamps may shrink. Managers of baldcypress swamps at the southern edge of the range may face special challenges in attempting to preserve these swamp habitats in the future if climates become warmer and drier.

43 CFR 2625.2 - Applications in conflict with swamp-land claims.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Applications in conflict with swamp-land...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.2 Applications in conflict with swamp-land claims. Applications adverse to the State...

43 CFR 2625.1 - Selection and patenting of swamp lands.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Selection and patenting of swamp lands... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.1 Selection and patenting of swamp lands. (a) All lands properly selected and reported to...

43 CFR 2625.2 - Applications in conflict with swamp-land claims.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Applications in conflict with swamp-land...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.2 Applications in conflict with swamp-land claims. Applications adverse to the State...

43 CFR 2625.1 - Selection and patenting of swamp lands.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Selection and patenting of swamp lands... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.1 Selection and patenting of swamp lands. (a) All lands properly selected and reported to...

43 CFR 2625.1 - Selection and patenting of swamp lands.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Selection and patenting of swamp lands... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.1 Selection and patenting of swamp lands. (a) All lands properly selected and reported to...

43 CFR 2625.2 - Applications in conflict with swamp-land claims.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Applications in conflict with swamp-land...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.2 Applications in conflict with swamp-land claims. Applications adverse to the State...

43 CFR 2625.1 - Selection and patenting of swamp lands.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Selection and patenting of swamp lands... LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.1 Selection and patenting of swamp lands. (a) All lands properly selected and reported to...

43 CFR 2625.2 - Applications in conflict with swamp-land claims.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Applications in conflict with swamp-land...) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.2 Applications in conflict with swamp-land claims. Applications adverse to the State...

Soil microbial communities of three grassland ecosystems in the Bayinbuluke, China.

PubMed

Shao, Keqiang; Gao, Guang

2018-03-01

The microbial community plays an important role in soil nutrient cycles and energy transformations in alpine grassland. In this study, we investigated the composition of the soil microbial community collected from alpine cold swamp meadow (ASM), alpine cold meadow (AM), and alpine cold desert steppe (ADS) within the Bayinbuluke alpine grassland, China, using Illumina amplicon sequencing. Of the 147 271 sequences obtained, 36 microbial phyla or groups were detected. The results showed that the ADS had lower microbial diversity than the ASM and AM, as estimated by the Shannon index. The Verrucomicrobia, Chloroflexi, Planctomycetes, Proteobacteria, and Actinobacteria were the predominant phyla in all 3 ecosystems. Particularly, Thaumarchaeota was only abundant in ASM, Bacteroidetes in AM, and Acidobacteria in ADS. Additionally, the predominant genus also differed with each ecosystem. Candidatus Nitrososphaera was predominant in ADS, the Pir4 lineage in ASM, and Sphingomonas in AM. Our results indicated that the soil microbial community structure was different for each grassland ecosystem in the Bayinbuluke.

Forested wetland habitat

USGS Publications Warehouse

Duberstein, Jamie A.; Krauss, Ken W.; Kennish, Michael J.

2015-01-01

A forested wetland (swamp) is a forest where soils are saturated or flooded for at least a portion of the growing season, and vegetation, dominated by trees, is adapted to tolerate flooded conditions. A tidal freshwater forested wetland is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity of soil porewater less than 0.5 g/l. It is known locally as tidal várzea in the Amazon delta, Brazil. A tidal saltwater forested wetland (mangrove forest) is a forested wetland that experiences frequent but short-term surface flooding via tidal action, with average salinity often exceeding 3 g/l and reaching levels that can exceed seawater. Mangrove ecosystems are composed of facultative halophytes that generally experience better growth at moderate salinity concentrations.

Greenhouse gas efflux from an impacted Malaysian tropical peat swamp (Invited)

NASA Astrophysics Data System (ADS)

Waldron, S.; Vihermaa, L. E.; Evers, S.; Garnett, M.; Newton, J.; Padfield, R.

2013-12-01

Tropical peatlands constitute ~11% of global peatland area and ~12% of the global peat C pool. Malaysia alone contains 10% of tropical peats. Due to rising global demands for food and biofuels, SE-Asia peat swamp forest ecosystems are threatened by increasing amounts of drainage, fire and conversion to plantation. These processes can change the GHG emissions and thus net ecosystem C balance. However, in comparison to temperate and boreal peatlands, there is a lack of data on terrestrial-aquatic-atmospheric carbon transfer from tropical peatlands, both those that are little disturbed and those facing anthropogenic pressures. Lateral transport of soil-respired carbon, and fluvial respiration or UV-oxidation of terrestrial DOC primes atmospheric carbon dioxide efflux. We now know that DOC lost from disturbed tropical peat swamp forests can be centuries to millennia old and originates deep within the peat column - this carbon may fuel efflux of old carbon dioxide and so anthropogenic land-use change renders the older, slower carbon cycles shorter and faster. Currently we have no knowledge of how significant ';older-slower' terrestrial-aquatic-atmospheric cycles are in disturbed tropical peatlands. Further, in some areas for commercial reasons, or by conservation bodies trying to minimise peat habitat loss, logged peats have been left to regenerate. Consequently, unpicking the legacy of multiple land uses on magnitude, age and source of GHG emissions is challenging but required to support land management decisions and projections of response to a changing climate. Here, we present the results of our first field campaign in July 2013 to the Raja Musa and Sungai Karang Peat Swamp Forest Reserves in North Selangor, Malaysia. This is one of Malaysia's largest oceanic peat swamps, and has been selectively logged and drained for 80 years, but is now subject to a 30 year logging ban to aid forest regeneration and build up wood stocks. From sites subject to different land use, we will present measurements of i) spatial variation in fluvial carbon dioxide and methane concentrations and associated efflux rates, and ii) the stable carbon isotopic composition of DIC and novel determination of the age of the effluxed carbon dioxide. From this we can consider if younger-faster or older-slower carbon cycling dominates the terrestrial-aquatic-atmospheric C transfer during this dry period sampling.

Paleoecological interpretation of a middle Pennsylvanian coal bed in the central Appalachian basin, U.S.A.

USGS Publications Warehouse

Eble, C.F.; Grady, W.C.

1990-01-01

At least 180 small spore species assignable to 62 miospore genera have been identified from the Middle Pennsylvanian Hernshaw coal bed in southern West Virginia, and its stratigraphic equivalent, the Fire Clay coal bed, in eastern Kentucky. The established natural affinities of a majority of these miospore taxa indicate that the Hernshaw-Fire Clay peat swamp supported a diverse flora consisting of arborescent and "herbaceous" lycopods, ferns (tree-like and small varities), calamities and cordaites. Four floral groupings are recognized in the Hernshaw-Fire Clay coal bed. The inferred paleoecology and vertical stratification of each of these four floral groupings is similar in structure to the "phasic" floral communities found in modern domed peat systems, suggesting that the ancient Hernshaw-Fire Clay peat swamp was a domed deposit. Compositional characteristics (petrographic make up, ash yield and sulfur content) associated with the four groupings are consistent with, and support this interpretation. Where uninterrupted by inorganic partings, the Hernshaw-Fire Clay coal bed commonly contains basal coal layers dominated by Lycospora-bearing arborescent lycopods, with successive increments showing a progression to a more fern- and "herbaceous"-lycopod-dominant flora in younger layers. These observations are corroborated by petrographic analyses, which show the bed to be compositionally stratified. Increments dominated by Lycospora have high vitrinite contents, in contrast to increments containing increased percentages of fern- and "herbaceous"-lycopod-affiliated taxa that are enriched in inertinite macerals. The volcanic ash fall, preserved as the flint-clay parting in the Hernshaw-Fire Clay coal bed, had a considerable effect on the development of the ancient Hernshaw-Fire Clay peat swamp. Besides interrupting peat formation, the presence of an inorganic substrate represent a major change in edaphic conditions within the swamp. This disruption is demonstrated by a change in palynflora and by the establishment and proliferation of some plant groups, notably cordaites and calamites, that may have been better adapted to growth on mineral soils. These palynologic and petrographic relationships, thought to be indicative of a domed peat-swamp origin, are not confined to the Hernshaw-Fire Clay coal bed, but appear to be characteristic of many coal beds in the Appalachian basin, and also of coal beds in other basins. ?? 1990.

Periodicity in stem growth and litterfall in tidal freshwater forested wetlands: influence of salinity and drought on nitrogen recycling

USGS Publications Warehouse

Cormier, Nicole; Krauss, Ken W.; Conner, William H.

2013-01-01

Many tidally influenced freshwater forested wetlands (tidal swamps) along the south Atlantic coast of the USA are currently undergoing dieback and decline. Salinity often drives conversion of tidal swamps to marsh, especially under conditions of regional drought. During this change, alterations in nitrogen (N) uptake from dominant vegetation or timing of N recycling from the canopy during annual litter senescence may help to facilitate marsh encroachment by providing for greater bioavailable N with small increases in salinity. To monitor these changes along with shifts in stand productivity, we established sites along two tidal swamp landscape transects on the lower reaches of the Waccamaw River (South Carolina) and Savannah River (Georgia) representing freshwater (≤0.1 psu), low oligohaline (1.1–1.6 psu), and high oligohaline (2.6–4.1 psu) stands; the latter stands have active marsh encroachment. Aboveground tree productivity was monitored on all sites through monthly litterfall collection and dendrometer band measurements from 2005 to 2009. Litterfall samples were pooled by season and analyzed for total N and carbon (C). On average between the two rivers, freshwater, low oligohaline, and high oligohaline tidal swamps returned 8,126, 3,831, and 1,471 mg N m−2 year−1, respectively, to the forest floor through litterfall, with differences related to total litterfall volume rather than foliar N concentrations. High oligohaline sites were most inconsistent in patterns of foliar N concentrations and N loading from the canopy. Leaf N content generally decreased and foliar C/N generally increased with salinization (excepting one site), with all sites being fairly inefficient in resorbing N from leaves prior to senescence. Stands with higher salinity also had greater flood frequency and duration, lower basal area increments, lower tree densities, higher numbers of dead or dying trees, and much reduced leaf litter fall (103 vs. 624 g m−2 year−1) over the five study years. Our data suggest that alternative processes, such as the rate of decomposition and potential for N mineralization, on tidal swamp sites undergoing salinity-induced state change may be more important for controlling N biogeochemical cycling in soils than differences among sites in N loading via litterfall.

Differences in Train-induced Vibration between Hard Soil and Soft Soil

NASA Astrophysics Data System (ADS)

Noyori, M.; Yokoyama, H.

2017-12-01

Vibration and noise caused by running trains sometimes raises environmental issues. Train-induced vibration is caused by moving static and dynamic axle loads. To reduce the vibration, it is important to clarify the conditions under which the train-induced vibration increases. In this study, we clarified the differences in train-induced vibration between on hard soil and on soft soil using a numerical simulation method. The numerical simulation method we used is a combination of two analysis. The one is a coupled vibration analysis model of a running train, a track and a supporting structure. In the analysis, the excitation force of the viaduct slabs generated by a running train is computed. The other analysis is a three-dimensional vibration analysis model of a supporting structure and the ground into which the excitation force computed by the former analysis is input. As a result of the numerical simulation, the ground vibration in the area not more than 25m from the center of the viaduct is larger under the soft soil condition than that under the hard soil condition in almost all frequency ranges. On the other hand, the ground vibration of 40 and 50Hz at a point 50m from the center of the viaduct under the hard soil condition is larger than that under the soft soil condition. These are consistent with the result of the two-dimensional FEM based on a ground model alone. Thus, we concluded that these results are obtained from not the effects of the running train but the vibration characteristics of the ground.

33 CFR 117.820 - Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (Alternate Route), Great Dismal Swamp Canal. 117.820 Section 117.820 Navigation and Navigable Waters COAST... North Carolina § 117.820 Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal. The draw of the Great Dismal Swamp Canal Bridge, mile 28.0 at South Mills, NC, shall operate as follows: (a...

33 CFR 117.820 - Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (Alternate Route), Great Dismal Swamp Canal. 117.820 Section 117.820 Navigation and Navigable Waters COAST... North Carolina § 117.820 Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal. The draw of the Great Dismal Swamp Canal Bridge, mile 28.0 at South Mills, NC, shall operate as follows: (a...

33 CFR 117.820 - Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (Alternate Route), Great Dismal Swamp Canal. 117.820 Section 117.820 Navigation and Navigable Waters COAST... North Carolina § 117.820 Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal. The draw of the Great Dismal Swamp Canal Bridge, mile 28.0 at South Mills, NC, shall operate as follows: (a...

33 CFR 117.820 - Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (Alternate Route), Great Dismal Swamp Canal. 117.820 Section 117.820 Navigation and Navigable Waters COAST... North Carolina § 117.820 Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal. The draw of the Great Dismal Swamp Canal Bridge, mile 28.0 at South Mills, NC, shall operate as follows: (a...

33 CFR 117.820 - Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (Alternate Route), Great Dismal Swamp Canal. 117.820 Section 117.820 Navigation and Navigable Waters COAST... North Carolina § 117.820 Atlantic Intracoastal Waterway (Alternate Route), Great Dismal Swamp Canal. The draw of the Great Dismal Swamp Canal Bridge, mile 28.0 at South Mills, NC, shall operate as follows: (a...

Impacts of sewage effluent on tree survival, water quality and nutrient removal in coastal plain swamps

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

Kuenzler, E.J.

1987-09-01

An investigation was conducted of the impacts of sprayed municipal sewage on swamp tree survival and the effects of the swamp system on nutrient concentrations below the outfalls on two streams on the coastal plain of North Carolina. Effluent was discharged to one swamp stream by aerial spraying and to the other stream by way of a small ditch. Ninety-eight percent of the trees struck directly by the spray were dead within 18 months of the date spraying began. Both swamp systems removed sufficient quantities of nitrogen and phosphorus within a few kilometers to account for virtually all of themore » sewage nutrient load to the swamps.« less

Sustainable materials used as stone column filler: A short review

NASA Astrophysics Data System (ADS)

Zukri, Azhani; Nazir, Ramli

2018-04-01

Stone columns (also known as granular piles) are one of the methods for soft soil stabilization and typically used to increase bearing capacity and stability of slope.; Apart from decreasing the compressibility of loose and fine graded soils, it also accelerates the consolidation effect by improving the drainage path for pore water pressure dissipation and reduces the liquefaction potential of soils during earthquake event. Stone columns are probably the most “natural” ground treatment method or foundation system in existence to date. The benefit of stone columns is owing to the partial replacement of compressible soil by more competent materials such as stone aggregate, sand and other granular materials. These substitutes also act as reinforcement material, hence increasing overall strength and stiffness of the soft soil. Nowadays, a number of research has been conducted on the behaviour and performance of stone columns with various materials utilized as column filler replacing the normal aggregate. This paper will review extensively on previously conducted research on some of the materials used as stone column backfill materials, its suitability and the effectiveness as a substitute for regular aggregates in soft soil improvement works.

Nonlinear and linear site response and basin effects in Seattle for the M 6.8 Nisqually, Washington, earthquake

USGS Publications Warehouse

Frankel, A.D.; Carver, D.L.; Williams, R.A.

2002-01-01

We used recordings of the M 6.8 Nisqually earthquake and its ML 3.4 aftershock to study site response and basin effects for 35 locations in Seattle, Washington. We determined site amplification from Fourier spectral ratios of the recorded horizontal ground motions, referenced to a soft-rock site. Soft-soil sites (generally National Earthquake Hazard Reduction Program [NEHRP] class E) on artificial fill and young alluvium have the largest 1-Hz amplifications (factors of 3-7) for both the mainshock and aftershock. These amplifications are correlated with areas of higher damage from the mainshock to major buildings and liquefaction. There are several indications of nonlinear response at the soft-soil sites for the mainshock ground motions, despite relatively modest peak accelerations in the S waves of 15%-22%g. First, the mainshock spectral ratios do not show amplification at 2-8 Hz as do the aftershock spectral ratios. Spectral peaks at frequencies below 2 Hz generally occur at lower frequencies for the mainshock spectral ratios than for the aftershock ratios. At one soft-soil site, there is a clear shift of the resonant frequency to a lower frequency for the mainshock compared with the aftershock. The frequency of this resonance increases in the coda of the mainshock record, indicating that the site response during the weaker motions of the coda is more linear than that of the initial S wave. Three of the soft-soil sites display cusped, one-sided mainshock accelerograms after the S wave. These soft-soil sites also show amplification at 10-20 Hz in the S wave, relative to the rock site, that is not observed for the aftershock. The cusped waveforms and 10-20-Hz amplification are symptomatic of nonlinear response at the soft-soil sites. These sites had nearby liquefaction. The largest amplifications for 0.5 Hz occur at soft-soil sites on the southern portion of the Seattle Basin. Stiff-soil sites (NEHRP classes D and C) on Pleistocene-age glacial deposits display similar spectral amplification for the mainshock and aftershock, indicating approximately linear response. The stiff-soil sites generally have moderate amplification (factors of 1.1-2.4) at 0.5 and 1 Hz. Amplifications at 1 and 5 Hz for all sites generally increase with decreasing shear-wave velocity measured in the top 30 m (Vs 30). However, larger amplifications at 0.5 and 1 Hz for sites with similar Vs 30 values are observed for sites in the Seattle Basin, illustrating the amplification from the deeper (>30 m) sediments and the contribution from basin surface waves. Record sections for the mainshock and aftershock show that basin surface waves produce the peak velocities for many of the sites in the Seattle Basin and often dominate the amplitude at 1 Hz and lower frequencies.

SwampLog II: A Structured Journal for Personal and Professional Inquiry within a Collaborative Environment.

ERIC Educational Resources Information Center

Nicassio, Frank J.

SwampLog is a type of journal keeping that records the facts of daily activities as experienced and perceived by practitioners. The label, "SwampLog," was inspired by Donald Schon's metaphor used to distinguish the "swamplands of practice" from the "high, hard ground of research." Keeping a SwampLog consists of recording four general types of…

Fish measurement using Android smart phone: the example of swamp eel

NASA Astrophysics Data System (ADS)

Chen, Baisong; Fu, Zhuo; Ouyang, Haiying; Sun, Yingze; Ge, Changshui; Hu, Jing

The body length and weight are critical physiological parameters for fishes, especially eel-like fishes like swamp eel(Monopterusalbus).Fast and accurate measuring of body length is significant for swamp eel culturing as well as its resource investigation and protection. This paper presents an Android smart phone-based photogrammetry technology for measuring and estimating the length and weight of swamp eel. This method utilizes the feature that the ratio of lengths of two objects within an image is equal to that of in reality to measure the length of swamp eels. And then, it estimates the weight via a pre-built length-weight regression model. Analysis and experimental results have indicated that this method is a fast and accurate method for length and weight measurements of swamp eel. The cross-validation results shows that the RMSE (root-mean-square error) of total length measurement of swamp eel is0.4 cm, and the RMSE of weight estimation is 11 grams.

Relation of drainage problems to high ground-water levels, Coconut Grove area, Oahu, Hawaii

USGS Publications Warehouse

Swain, L.A.; Huxel, C.J.

1971-01-01

Purpose and Scope In 1969, hydrologic data-collection sites were established in and around the Coconut Grove area for the purpose of measuring directly the relationship between rainfall, runoff, ground-water levels, the level of water in Kawainui Swamp and the canals, and tidal fluctuations. The primary objective was to identify the causes of the occurrence and persistence of flooding and to gain data on which to base recommendations for remedial action. The scope of the study included establishing and operating flow and stage-recording gages on the Swamp, Kawainui Canal, and the inner canal; periodic and repeated measurements of ground-water level in test borings throughout the residential area; collection and analysis of soil and construction borings made for engineering purposes; the assembly and analysis of all available data relating surface and subsurface flow conditions, and the development of conclusions as to the causes and means to alleviate the flooding. This report summarizes the information collected from October 1969 to June 1971, includes analysis of the data, and discusses the probable causes of flooding.

Geomorphic controls on fluvial carbon exports and emissions from upland swamps in eastern Australia.

PubMed

Cowley, Kirsten; Looman, Arun; Maher, Damien T; Fryirs, Kirstie

2018-03-15

Temperate Highland Peat Swamps on Sandstone (THPSS) are upland wetlands, similar to fens in the Northern Hemisphere and are found at the headwaters of low-order streams on the plateaus of Eastern Australia. They are classified as endangered ecological communities under State and National legislation. Previous works have identified particular geomorphic characteristics that are important to carbon storage in these low energy sediment accumulation zones. Changes in the geomorphic structure of THPSS, such as channelisation, may have profound implications for carbon storage. To assess the effect of channelisation on carbon budgets in these ecosystems it is essential to identify and quantify differences in carbon export, emissions and stocks of carbon of intact swamps and those that have become channelised. We undertook seasonal sampling of the perched swamp aquifers and surface waters of two intact swamps and two channelised fills in the Blue Mountains of New South Wales, Australia, to investigate differences in carbon exports and emissions between the two swamp types. We found that channelised fills' mean CO 2 emissions were almost four times higher than intact swamps with mean CH 4 emissions up to five times higher. Annual fluvial carbon exports for channelised fills were up to 18 times that of intact swamps. Channelised fill exports and emissions can represent up to 2% of the total swamp carbon stocks per annum which is 40 times higher than the intact swamps. This work clearly demonstrates that changes in geomorphic structure brought about by incision and channelisation results in profound changes to the carbon storage function of THPSS. Copyright © 2017 Elsevier B.V. All rights reserved.

Food Swamps Predict Obesity Rates Better Than Food Deserts in the United States.

PubMed

Cooksey-Stowers, Kristen; Schwartz, Marlene B; Brownell, Kelly D

2017-11-14

This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data from the United States Department of Agriculture (USDA) Food Environment Atlas, the American Community Survey, and a commercial street reference dataset. We employed an instrumental variables (IV) strategy to correct for the endogeneity of food environments (i.e., that individuals self-select into neighborhoods and may consider food availability in their decision). Our results suggest that the presence of a food swamp is a stronger predictor of obesity rates than the absence of full-service grocery stores. We found, even after controlling for food desert effects, food swamps have a positive, statistically significant effect on adult obesity rates. All three food swamp measures indicated the same positive association, but reflected different magnitudes of the food swamp effect on rates of adult obesity ( p values ranged from 0.00 to 0.16). Our adjustment for reverse causality, using an IV approach, revealed a stronger effect of food swamps than would have been obtained by naïve ordinary least squares (OLS) estimates. The food swamp effect was stronger in counties with greater income inequality ( p < 0.05) and where residents are less mobile ( p < 0.01). Based on these findings, local government policies such as zoning laws simultaneously restricting access to unhealthy food outlets and incentivizing healthy food retailers to locate in underserved neighborhoods warrant consideration as strategies to increase health equity.

Food Swamps Predict Obesity Rates Better Than Food Deserts in the United States

PubMed Central

Cooksey-Stowers, Kristen; Schwartz, Marlene B.; Brownell, Kelly D.

2017-01-01

This paper investigates the effect of food environments, characterized as food swamps, on adult obesity rates. Food swamps have been described as areas with a high-density of establishments selling high-calorie fast food and junk food, relative to healthier food options. This study examines multiple ways of categorizing food environments as food swamps and food deserts, including alternate versions of the Retail Food Environment Index. We merged food outlet, sociodemographic and obesity data from the United States Department of Agriculture (USDA) Food Environment Atlas, the American Community Survey, and a commercial street reference dataset. We employed an instrumental variables (IV) strategy to correct for the endogeneity of food environments (i.e., that individuals self-select into neighborhoods and may consider food availability in their decision). Our results suggest that the presence of a food swamp is a stronger predictor of obesity rates than the absence of full-service grocery stores. We found, even after controlling for food desert effects, food swamps have a positive, statistically significant effect on adult obesity rates. All three food swamp measures indicated the same positive association, but reflected different magnitudes of the food swamp effect on rates of adult obesity (p values ranged from 0.00 to 0.16). Our adjustment for reverse causality, using an IV approach, revealed a stronger effect of food swamps than would have been obtained by naïve ordinary least squares (OLS) estimates. The food swamp effect was stronger in counties with greater income inequality (p < 0.05) and where residents are less mobile (p < 0.01). Based on these findings, local government policies such as zoning laws simultaneously restricting access to unhealthy food outlets and incentivizing healthy food retailers to locate in underserved neighborhoods warrant consideration as strategies to increase health equity. PMID:29135909

12. LOCK GATES AT THE SWAMP LOCKS, SEPARATING THE UPPER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

12. LOCK GATES AT THE SWAMP LOCKS, SEPARATING THE UPPER AND LOWER LOCK CHAMBERS, SHOWING PADDLE VALVES, LOOKING WEST: 1976 - Pawtucket Canal, Swamp Locks, Pawtucket & Merrimack Canals, Lowell, Middlesex County, MA

Soil moisture and texture primarily control the soil nutrient stoichiometry across the Tibetan grassland.

PubMed

Tian, Liming; Zhao, Lin; Wu, Xiaodong; Fang, Hongbing; Zhao, Yonghua; Hu, Guojie; Yue, Guangyang; Sheng, Yu; Wu, Jichun; Chen, Ji; Wang, Zhiwei; Li, Wangping; Zou, Defu; Ping, Chien-Lu; Shang, Wen; Zhao, Yuguo; Zhang, Ganlin

2018-05-01

Soil nutrient stoichiometry and its environmental controllers play vital roles in understanding soil-plant interaction and nutrient cycling under a changing environment, while they remain poorly understood in alpine grassland due to lack of systematic field investigations. We examined the patterns and controls of soil nutrients stoichiometry for the top 10cm soils across the Tibetan ecosystems. Soil nutrient stoichiometry varied substantially among vegetation types. Alpine swamp meadow had larger topsoil C:N, C:P, N:P, and C:K ratios compared to the alpine meadow, alpine steppe, and alpine desert. In addition, the presence or absence of permafrost did not significantly impact soil nutrient stoichiometry in Tibetan grassland. Moreover, clay and silt contents explained approximately 32.5% of the total variation in soil C:N ratio. Climate, topography, soil properties, and vegetation combined to explain 10.3-13.2% for the stoichiometry of soil C:P, N:P, and C:K. Furthermore, soil C and N were weakly related to P and K in alpine grassland. These results indicated that the nutrient limitation in alpine ecosystem might shifts from N-limited to P-limited or K-limited due to the increase of N deposition and decrease of soil P and K contents under the changing climate conditions and weathering stages. Finally, we suggested that soil moisture and mud content could be good predictors of topsoil nutrient stoichiometry in Tibetan grassland. Copyright © 2017 Elsevier B.V. All rights reserved.

Soil mixing design methods and construction techniques for use in high organic soils.

DOT National Transportation Integrated Search

2015-06-01

Organic soils present a difficult challenge for roadway designers and construction due to the high : compressibility of the soil structure and the often associated high water table and moisture content. For : other soft or loose inorganic soils, stab...

Hydrology, vegetation, and soils of riverine and tidal floodplain forests of the lower Suwannee River, Florida, and potential impacts of flow reductions

USGS Publications Warehouse

Light, Helen M.; Darst, Melanie R.; Lewis, Lori J.; Howell, David A.

2002-01-01

A study relating hydrologic conditions, soils, and vegetation of floodplain forests to river flow was conducted in the lower Suwannee River, Florida, from 1996 to 2000. The study was done by the U.S. Geological Survey in cooperation with the Suwannee River Water Management District to help determine the minimum flows and levels required for wetlands protection. The study area included forests within the 10-year floodplain of the Suwannee River from its confluence with the Santa Fe River to the tree line (lower limit of forests) near the Gulf of Mexico, and covered 18,600 hectares (ha) of forests, 75 percent of which were wetlands and 25 percent uplands. The floodplain was divided into three reaches, riverine, upper tidal, and lower tidal, based on changes in hydrology, vegetation, and soils with proximity to the coast. The Suwannee River is the second largest river in Florida in terms of average discharge. Median flow at the confluence of the Suwannee and Santa Fe Rivers is approximately 181 cubic meters per second (m3/s) or 6,480 cubic feet per second (ft3/s) (1933-99). At the upper end of the riverine reach, river stages are unaffected by tides and have a typical annual range of 4.1 meters (m). Tides affect river stages at low and medium flows in the upper tidal reach, and at all flows in the lower tidal reach. Median tidal range at the mouth of the Suwannee River is about 1 m. Salinity of river water in the lower tidal reach increases with decreasing flow and proximity to the Gulf of Mexico. Vertically averaged salinity in the river near the tree line is typically about 5 parts per thousand at medium flow. Land-surface elevation and topographic relief in the floodplain decrease with proximity to the coast. Elevations range from 4.1 to 7.3 m above sea level at the most upstream riverine transect and from 0.3 to 1.3 m above sea level on lower tidal transects. Surface soils in the riverine reach are predominantly mineral and dry soon after floods recede except in swamps. Surface soils in upper and lower tidal reaches are predominantly organic, saturated mucks. In the downstream part of the lower tidal reach, conductivities of surface soils are high enough (greater than 4 milli-mhos per centimeter) to exclude many tree species that are intolerant of salinity. Species richness of canopy and subcanopy plants in wetland forests in the lower Suwannee River is high compared to other river floodplains in North America. A total of 77 tree, shrub, and woody vine species were identified in the canopy and subcanopy of floodplain wetland forests (n = 8,376). Fourteen specific forest types were mapped using digitized aerial photographs, defined from vegetative sampling, and described in terms of plant species composition. For discussion purposes, some specific wetland types were combined, resulting in three general wetland forest types for each reach. Riverine high bottomland hardwoods have higher canopy species richness than all other forest types (40-42 species), with Quercus virginiana the most important canopy tree by basal area. The canopy composition of riverine low bottomland hardwoods is dominated by five species with Quercus laurifolia the most important by basal area. Riverine swamps occur in the lowest and wettest areas with Taxodium distichum the most important canopy species by basal area. Upper tidal bottomland hardwoods are differentiated from riverine forests by the presence of Sabal palmetto in the canopy. Upper tidal mixed forests and swamps are differentiated from riverine forests, in part, by the presence of Fraxinus profunda in the canopy. Nyssa aquatica, the most important canopy species by basal area in upper tidal swamps, is absent from most forests in the lower tidal reach where its distribution is probably restricted by salinity. Hydric hammocks, a wetland type that is rare outside of Florida, are found in the lower tidal reach and are flooded every 1-2 years by either storm surge or river floods. Lowe

The effects of flooding and sedimentation on seed germination of two bottomland hardwood tree species

USGS Publications Warehouse

Pierce, Aaron R.; King, S.L.

2007-01-01

Flooding and sedimentation are two of the dominant disturbances that influence tree species composition and succession in floodplain forests. The importance of these disturbances may be most notable during the germination and establishment phases of plant succession. Channelization of most alluvial systems in the southeastern United States has caused dramatic and systematic alterations to both hydrologic and sedimentation processes of floodplain systems. We determined the influence of these altered abiotic processes on the germination and growth of two common floodplain tree species: swamp chestnut oak (Quercus michauxii Nutt.) and overcup oak (Q. lyrata Walt.). Flood durations of 0 days, 15 days, and 30 days prior to germination was a factor in germination, but the effect varied by species. For instance, ovcrcup oak, which has a higher tolerance to flooding than swamp chestnut oak, had higher germination rates in the flooded treatments (15-day x?? = 78% and 30-day x?? = 85%) compared to the non-flooded treatment (x?? = 54%). In contrast, germination rates of swamp chestnut oak were negatively affected by the 30-day flood treatment. Sediment deposition rates of 2 cm of top soil, 2 cm of sand, and 8 cm of sand also affected germination, but were secondary to flood duration. The main effect of the sediment treatment in this experiment was a reduction in above-ground height of seedlings. Our study provides evidence for the importance of both flooding and sedimentation in determining tree species composition in floodplain systems, and that tolerance levels to such stressors vary by species. ?? 2007, The Society of Wetland Scientists.

Probability of Archaeological Site Occurrence in the Northern Portion of the Birds Point-New Madrid Floodway: An Analysis of the Distribution of Cultural Resources and Environmental Features

DTIC Science & Technology

1987-10-30

Geography The Mississippi River stretches from Lake Itasca, Minnesota to the Gulf of Mexico. The southern half of this river system is known as the...slight (0-2%) with moderate drainage. I In areas where water stands, fine grained sediments will be deposited. As a result floodplain lakes , swamps and...of the county (Tandarich and Reagan 1978:11) but it is not present in the study area. Tiptonville- Reelfoot These soils are silty throughout and are

A Cultural Resources Survey of Steele, New Franklin, and Main Ditches, and National Register of Historic Places Significance Testing of Sites 2PM574, 575, 577, and 23PM578, Pemiscot County Missouri

DTIC Science & Technology

1990-07-15

last successional stage plant communities. Research using soils and plant communities to model prehistoric occupation in northeast Arkansas (Dekin et al...floods) since their formation. Levee/Swamp Ecotone This modeled macrobiotic coimmunity is what Lewis (1974:24-25) has called the Sweetgum-Elm-Cypress...especially cypress, would have been exploitable in this environment with land- based technology. 15 Included in these modeled strata are the different

Swamp land optimization in supporting food security and enhancing farmers welfare in South Sumatra Indonesia

NASA Astrophysics Data System (ADS)

Herwenita; Hutapea, Y.

2018-02-01

Swamp land in Indonesia spread in Sumatra, Kalimantan and West Papua. In Sumatra the largest swamp land area is located in South Sumatera Province. Unfortunately only few of the areas have been utilized due to its fragility, in which farmers could only cultivate rice on it once a year. The purpose of this paper is to develop a feasible farming pattern in swamp land to help farmers and practitioners in optimizing it by managing its water level. Shallow and mid swamp land can be cultivated using rotation model of crops (rice, corn, cassava), horticulture (cucumber, long beans, watermelon etc), fish farming (catfish, snake head fish, tilapia), and duck farming, whereas submergence tolerant rice varieties can be cultivated alternating with fish farming in deep swamp land. This study shows that such swamp land management is financially feasible showing by its positive NPV value, BCR value is above 1.00, and IRR value is greater than the interest rate. Therefore, implementation of this farming pattern is expected to increase farmers’ income and household food supply as well as village food supply.

Evaluation of dynamic response for monopole and hybrid wind mill tower

NASA Astrophysics Data System (ADS)

Shah, Hemal J.; Desai, Atul K.

2017-07-01

The wind mill towers are constructed using monopoles or lattice type tower. As the height of tower increases it gives more power but it becomes uneconomical, so in the present research work innovative wind mill tower such as combination of monopole and lattice tower is analyzed using FEM software. When the tall structures are constructed on soft soil it becomes dynamically sensitive so 3 types of soil such as hard, medium and soft soil is also modeled and the innovative tower is studied for different operating frequencies of wind turbine. From study it is concluded that the innovative tower will reduce resonance condition considering soil structure interaction.

Study on soil-pile-structure-TMD interaction system by shaking table model test

NASA Astrophysics Data System (ADS)

Lou, Menglin; Wang, Wenjian

2004-06-01

The success of the tuned mass damper (TMD) in reducing wind-induced structural vibrations has been well established. However, from most of the recent numerical studies, it appears that for a structure situated on very soft soil, soil-structure interaction (SSI) could render a damper on the structure totally ineffective. In order to experimentally verify the SSI effect on the seismic performance of TMD, a series of shaking table model tests have been conducted and the results are presented in this paper. It has been shown that the TMD is not as effective in controlling the seismic responses of structures built on soft soil sites due to the SSI effect. Some test results also show that a TMD device might have a negative impact if the SSI effect is neglected and the structure is built on a soft soil site. For structures constructed on a soil foundation, this research verifies that the SSI effect must be carefully understood before a TMD control system is designed to determine if the control is necessary and if the SSI effect must be considered when choosing the optimal parameters of the TMD device.

Embedded Empiricisms in Soft Soil Technology

NASA Astrophysics Data System (ADS)

Wijeyesekera, D. C.; John, L. M. S. Alvin; Adnan, Z.

2016-07-01

Civil engineers of today are continuously challenged by innovative projects that push further the knowledge boundaries with conceptual and/or ingenious solutions leading to the realization of that once was considered impossible in the realms of geotechnology. Some of the forward developments rely on empirical methods embedded within soft soil technology and the spectral realms of engineering in its entirety. Empiricisms unlike folklore are not always shrouded in mysticism but can find scientific reasoning to justify them being adopted in design and tangible construction projects. This lecture therefore is an outline exposition of how empiricism has been integrally embedded in total empirical beginnings in the evolution of soft soil technology from the Renaissance time, through the developments of soil mechanics in the 19th century which in turn has paved the way to the rise of computational soil mechanics. Developments in computational soil mechanics has always embraced and are founded on a wide backdrop of empirical geoenvironment simulations. However, it is imperative that a competent geotechnical engineer needs postgraduate training combined with empiricism that is based on years of well- winnowed practical experience to fathom the diverseness and complexity of nature. However, experience being regarded more highly than expertise can, perhaps inadvertently, inhibit development and innovation.

Soil mixing design methods and construction techniques for use in high organic soils : [summary].

DOT National Transportation Integrated Search

2015-10-01

The soils which serve as foundations for construction projects may be roughly classified as : inorganic or organic. Inorganic soils vary in firmness and suitability for construction. Soft : or loose inorganic soils may be stabilized using cement or s...

Saprophytic and Potentially Pathogenic Fusarium Species from Peat Soil in Perak and Pahang

PubMed Central

Karim, Nurul Farah Abdul; Mohd, Masratulhawa; Nor, Nik Mohd Izham Mohd; Zakaria, Latiffah

2016-01-01

Isolates of Fusarium were discovered in peat soil samples collected from peat swamp forest, waterlogged peat soil, and peat soil from oil palm plantations. Morphological characteristics were used to tentatively identify the isolates, and species confirmation was based on the sequence of translation elongation factor-1α (TEF-1α) and phylogenetic analysis. Based on the closest match of Basic Local Alignment Search Tool (BLAST) searches against the GenBank and Fusarium-ID databases, five Fusarium species were identified, namely F. oxysporum (60%), F. solani (23%), F. proliferatum (14%), F. semitectum (1%), and F. verticillioides (1%). From a neighbour-joining tree of combined TEF-1α and β-tubulin sequences, isolates from the same species were clustered in the same clade, though intraspecies variations were observed from the phylogenetic analysis. The Fusarium species isolated in the present study are soil inhabitants and are widely distributed worldwide. These species can act as saprophytes and decomposers as well as plant pathogens. The presence of Fusarium species in peat soils suggested that peat soils could be a reservoir of plant pathogens, as well-known plant pathogenic species such F. oxysporum, F. solani, F. proliferatum, and F. verticillioides were identified. The results of the present study provide knowledge on the survival and distribution of Fusarium species. PMID:27019679

Mercury in swamp sparrows (Melospiza georgiana) from wetland habitats in Wisconsin.

PubMed

Strom, Sean M; Brady, Ryan S

2011-10-01

Wetlands play a major role in the export of methylmercury (MeHg) to a watershed. The large contribution of wetlands to watersheds in northern Wisconsin, coupled with the acidic environment of this area, makes these habitats especially vulnerable to mercury (Hg) accumulation by biota. The purpose of this study was to compare Hg accumulation between northern Wisconsin wetlands and southern Wisconsin wetlands using the swamp sparrow (Melospiza georgiana) as a representative species. The swamp sparrow was selected as a representative passerine species in which to examine Hg in these habitats, because during their breeding season, they feed at a higher trophic level than many of their counterparts. During the breeding seasons of 2007 and 2008, blood samples were collected from swamp sparrows inhabiting wetlands in both northern and southern Wisconsin and analyzed for total Hg. The mean concentration of total Hg in swamp sparrows from northern wetlands was 0.135 ± 0.064 μg/ml while the mean concentration of total Hg in swamp sparrows from southern wetlands was 0.187 ± 0.106 μg/ml. Results revealed no significant difference (P = 0.17) between Hg accumulation in swamp sparrows from less-acidic wetlands in southern Wisconsin and Hg in swamp sparrows from acidic wetlands in northern Wisconsin. The results are contrary to those observed in other species such as common loon, tree swallow and river otter where higher accumulation has been observed in individuals from acidic habitats. Reasons for the lack of this accumulation pattern in swamp sparrows are unclear and warrant further study.

Restoration methods for deepwater swamps

Treesearch

William H. Conner; Kenneth W. McLeod; Ellen Colodney

2000-01-01

Planting in deepwater swamp areas is difficult and time consuming, and nursery-grown seedlings are often not suited for such conditions. Baldcypress [Taxodium distichum (L.) Rich.], water tupelo (Nyssa aquatica L.), swamp blackgum [N. sylvatica var. biflora (Walt.) Sarg.], and green ash (

Soft Soil Improvement for Sub-grade Layer Using Hexagonal Micropiles Layout

NASA Astrophysics Data System (ADS)

Ambak, K.; Abdullah, N. A. H.; Yusoff, M. F.; Abidin, M. H. Z.

2018-04-01

Soft soil problems are often associated with sediment and stability where it represents a major challenge in Geotechnical Engineering. Research on a soft soil was carried out to determine the level of sediment resulting from the applied load and thus compare the most ideal form of arrangement by the results obtained from bearing capacity. The study was conducted at Research Centre for Soft Soil (RECESS), UTHM by using kaolin. There are several tests conducted on kaolin before the arrangement of pile which is liquid limit test. Through these tests, the level of water content can be maintained which is 1.2 liquid limit where it is in the homogeneous condition. Density test also carried to know weight of kaolin and water that needed in the model. Meanwhile, large strain consolidation test carried on the soil by placing a load of 8 kPa. Then, the pile was arranged in the soil in the shape of a hexagon and square. Load was increased to 12 kPa and imposed on the surface of the pile with a different forms. After 24 hours, the reading of sediment was measured everyday and the process collecting data conducted for 3 week. Based on data obtained, time against sediment can be plotted. To determine the bearing capacity, direct shear test was conducted to get the value coefficient of cohesion, c as a parameter in the calculation of the soil bearing capacity. The results showed that the rate of settlement occurs is different where hexagonal form less the rate of settlement compared to square form which is 64.2% while the results of bearing capacity have the same value.

Tools to support maintenance strategies under soft soil conditions

NASA Astrophysics Data System (ADS)

Lambert, J. W. M.; van Meerten, J. J.; Woning, M. P.; Eijbersen, M. J.; Huber, M.

2015-11-01

Costs for maintenance of infrastructure in municipalities with soft soil underground conditions, are estimated to be almost 40 % higher than in others. As a result, these municipalities meet financial problems that cause overdue maintenance. In some cases municipalities are even afraid to be unable to offer a minimum service level in future. In common, traditional practice, roads and sewerage systems have been constructed in trenches that consist of sandy material that replaces the upper meters of the soft soil. Under influence of its weight, this causes accelerated settlements of the construction. A number of alternative constructions have been developed, e.g. using light-weight materials to limit settlement velocity. In order to limit future maintenance costs, improvement of maintenance strategies is desired. Tools have been and will be developed to support municipalities in improving their maintenance strategies and save money by doing that. A model (BALANS) that weighs the attractiveness of alternative solutions under different soil, environmental and economic circumstances, will be presented.

The scientific value and potential of New Zealand swamp kauri

NASA Astrophysics Data System (ADS)

Lorrey, Andrew M.; Boswijk, Gretel; Hogg, Alan; Palmer, Jonathan G.; Turney, Christian S. M.; Fowler, Anthony M.; Ogden, John; Woolley, John-Mark

2018-03-01

New Zealand swamp kauri (Agathis australis) are relic trees that have been buried and preserved in anoxic bog environments of northern New Zealand for centuries through to hundreds of millennia. Kauri are massive in proportion to other native New Zealand trees and they can attain ages greater than 1000 years. The export market for swamp (subfossil) kauri has recently been driven by demand for a high-value workable timber, but there are concerns about the sustainability of the remaining resource, a situation exacerbated in recent years by the rapid extraction of wood. Economic exploitation of swamp kauri presents several unique opportunities for Quaternary science, however the scientific value of this wood is not well understood by the wider research community and public. Here, we summarise the history of scientific research on swamp kauri, and explore the considerable potential of this unique resource. Swamp kauri tree-ring chronologies are temporally unique, and secondary analyses (such as radiocarbon and isotopic analyses) have value for improving our understanding of Earth's recent geologic history and pre-instrumental climate history. Swamp kauri deposits that span the last interglacial-glacial cycle show potential to yield "ultra-long" multi-millennia tree-ring chronologies, and composite records spanning large parts of MIS3 (and most of the Holocene) may be possible. High-precision radiocarbon dating of swamp kauri chronologies can improve the resolution of the global radiocarbon calibration curve, while testing age modelling and chronologic alignment of other independent long-term high-resolution proxy records. Swamp kauri also has the potential to facilitate absolute dating and verification of cosmogenic events found in long Northern Hemisphere tree-ring chronologies. Future efforts to conserve these identified values requires scientists to work closely with swamp kauri industry operators, resource consent authorities, and export regulators to mitigate potential losses to science as this precious material is progressively extracted from the ground and utilized.

Lower food chain community study: thermal effects and post-thermal recovery in the streams and swamps of the Savannah River Plant

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

Kondratieff, P.; Kondratieff, B.C.

1985-07-01

The effects of thermal stress on lower food chain communities of streams and swamps of the Savannah River Plant. Both the autotroph assemblages and the macro invertebrate communities were studied in streams receiving heated reactor effluent. To document stream and swamp ecosystem recovery from thermal stress, the same communities of organisms were studied in a stream/swamp ecosystem which had received heated reactor effluent in the past. (ACR)

How could a freshwater swamp produce a chemical signature characteristic of a saltmarsh?

USGS Publications Warehouse

McCloskey, Terrence; Smith, Christopher G.; Liu, Kam-biu; Marot, Marci E.; Haller, Christian

2018-01-01

Reduction–oxidation (redox) reaction conditions, which are of great importance for the soil chemistry of coastal marshes, can be temporally dynamic. We present a transect of cores from northwest Florida wherein radical postdepositional changes in the redox regime has created atypical geochemical profiles at the bottom of the sedimentary column. The stratigraphy is consistent along the transect, consisting of, from the bottom upward, carbonate bedrock, a gray clay, an organic mud section, a dense clay layer, and an upper organic mud unit representing the current saltwater marsh. However, the geochemical signature of the lower organic mud unit suggests pervasive redox reactions, although the interval has been identified as representing a freshwater marsh, an unlikely environment for such conditions. Analyses indicate that this discrepancy results from postdepositional diagenesis driven by millennial-scale environmental parameters. Rising sea level that led to the deposition of the capping clay layer, created anaerobic conditions in the freshwater swamp interval, and isolated it hydrologically from the rest of the sediment column. The subsequent infiltration of marine water into this organic material led to sulfate reduction, the buildup of H2S and FeS, and anoxic conditions. Continued sulfidation eventually resulted in euxinic conditions, as evidenced by elevated levels of Fe, S, and especially Mo, the diagnostic marker of euxinia. Because this chemical transformation occurred long after the original deposition the geochemical signature does not reflect soil chemistry at the time of deposition and cannot be used to infer syn-depositional environmental conditions, emphasizing the importance of recognizing diagenetic processes in paleoenvironmental studies.

Imported Asian swamp eels (Synbranchidae: Monopterus) in North American live food markets: Potential vectors of non-native parasites

USGS Publications Warehouse

Nico, Leo G.; Sharp, Paul; Collins, Timothy M.

2011-01-01

Since the 1990s, possibly earlier, large numbers of Asian swamp eels (Synbranchidae: Monopterus spp.), some wild-caught, have been imported live from various countries in Asia and sold in ethnic food markets in cities throughout the USA and parts of Canada. Such markets are the likely introduction pathway of some, perhaps most, of the five known wild populations of Asian swamp eels present in the continental United States. This paper presents results of a pilot study intended to gather baseline data on the occurrence and abundance of internal macroparasites infecting swamp eels imported from Asia to North American retail food markets. These data are important in assessing the potential role that imported swamp eels may play as possible vectors of non-native parasites. Examination of the gastrointestinal tracts and associated tissues of 19 adult-sized swamp eels—identified as M. albus "Clade C"—imported from Vietnam and present in a U.S. retail food market revealed that 18 (95%) contained macroparasites. The 394 individual parasites recovered included a mix of nematodes, acanthocephalans, cestodes, digeneans, and pentastomes. The findings raise concern because of the likelihood that some parasites infecting market swamp eels imported from Asia are themselves Asian taxa, some possibly new to North America. The ecological risk is exacerbated because swamp eels sold in food markets are occasionally retained live by customers and a few reportedly released into the wild. For comparative purposes, M. albus "Clade C" swamp eels from a non-native population in Florida (USA) were also examined and most (84%) were found to be infected with internal macroparasites. The current level of analysis does not allow us to confirm whether these are non-native parasites.

Regeneration potential of Taxodium distichum swamps and climate change

USGS Publications Warehouse

Middleton, B.A.

2009-01-01

Seed bank densities respond to factors across local to landscape scales, and therefore, knowledge of these responses may be necessary in forecasting the effects of climate change on the regeneration of species. This study relates the seed bank densities of species of Taxodium distichum swamps to local water regime and regional climate factors at five latitudes across the Mississippi River Alluvial Valley from southern Illinois to Louisiana. In an outdoor nursery setting, the seed banks of twenty-five swamps were exposed to non-flooded (freely drained) or flooded treatments, and the number and species of seeds germinating were recorded from each swamp during one growing season. Based on ANOVA analysis, the majority of dominant species had a higher rate of germination in non-flooded versus flooded treatments. Similarly, an NMS comparison, which considered the local water regime and regional climate of the swamps, found that the species of seeds germinating, almost completely shifted under non-flooded versus flooded treatments. For example, in wetter northern swamps, seeds of Taxodium distichum germinated in non-flooded conditions, but did not germinate from the same seed banks in flooded conditions. In wetter southern swamps, seeds of Eleocharis cellulosa germinated in flooded conditions, but did not germinate in non-flooded conditions. The strong relationship of seed germination and density relationships with local water regime and regional climate variables suggests that the forecasting of climate change effects on swamps and other wetlands needs to consider a variety of interrelated variables to make adequate projections of the regeneration responses of species to climate change. Because regeneration is an important aspect of species maintenance and restoration, climate drying could influence the species distribution of these swamps in the future. ?? 2008 Springer Science+Business Media B.V.

Coal ball formation and a soil extinction near the P-Tr boundary

NASA Astrophysics Data System (ADS)

Breecker, D.; Royer, D. L.

2017-12-01

Coal balls are calcium carbonate accumulations that commonly permineralize paleotropical PermoCarboniferous coal deposits and preserve exceptional specimens of the coal swamp flora. A widely applicable model for the origin of coal balls is lacking despite the study of these deposits for over a century. Two characteristics of coal balls have been particularly challenging to explain: 1) their temporal range is restricted to the PermoCarboniferous and 2) their typical oxygen isotope and elemental compositions paradoxically indicate freshwater and marine origins, respectively. We propose a new model for coal ball formation. The first step in our model is the episodic delivery of seawater and marine carbonate sediment to coastal mires. Next, these waters are diluted by freshwater and the carbonates dissolve at the elevated pCO2 of the mire subsurface. Finally, as waters flow laterally through stands of arborescent lycopsids, aqueous CO2 in the pore spaces of the peat escapes by diffusion through the air-filled lycopsid rootlets into the overlying water column, where some rootlets are thought to have extended. The CO2 escape drives calcite precipitation in the soil zone. This model explains the narrow temporal occurrence of coal balls, which coincides with the peak diversity of arborescent lycopsids. It also resolves the geochemical conundrum; dilution by freshwater can result in relatively low pore water δ18O values without preventing high-Mg calcite formation. Furthermore, we show mathematically that for published densities of arborescent lycopsid root mats and for reasonable rates of lateral water flow and vertical peat accumulation, CO2 could escape rapidly enough through the rootlets to fill >35% of the porosity with calcite before substantial burial (top several decimeters of peat), explaining the exceptional preservation of coal swamp flora. Therefore, we suggest that coal balls are pedogenic in origin and that their disappearance from the rock record represents the first documented soil extinction on a vegetated planet.

Controls on northern wetland methane emissions: insights from regional synthesis studies and the Alaska Peatland Experiment (APEX)

NASA Astrophysics Data System (ADS)

Turetsky, M. R.; Euskirchen, E. S.; Czimczik, C. I.; Waldrop, M. P.; Olefeldt, D.; Fan, Z.; Kane, E. S.; McGuire, A. D.; Harden, J. W.

2014-12-01

Wetlands are the largest natural source of atmospheric methane. Static chambers have been used to quantify variation in wetland CH4 flux for many decades. Regional to global scale synthesis studies of static chamber measurements show that relationships between temperature, water availability and CH4 emissions depend on wetland type (bog, fen, swamp), region (tropical, temperate, arctic) and disturbance. For example, while water table position and temperature serve as the dominant controls on bog and swamp CH4 flux, vegetation is an important control on emissions from fens. These studies highlight the fact that wetland types have distinct controls on CH4 emissions; however, it is unlikely that modeling of wetland CH4 flux will improve without a better mechanistic understanding of the processes underlying CH4 production, transport, and oxidation. At the Alaska Peatland Experiment, we are quantifying CH4 emission using static chambers, automated chambers, and towers. Our sites vary in permafrost regime, including groundwater fens without permafrost, forested peat plateaus with intact permafrost, and collapse scar bogs formed through permafrost thaw. Experimental studies that examine plant and microbial responses to altered water table position and soil temperature are complemented by a gradient approach, where we use a space-for-time substitutions to examine the consequences of thaw on time-scales of decades to centuries. Our results thus far have documented the importance of soil rewetting in governing large CH4 fluxes from northern wetland soils. Accounting for CH4, our collapse scar bog significantly contributed to the global warming potential of the landscape. A major objective of our work is to explore the role of permafrost C release in greenhouse gas fluxes from wetland soils, which we are assessing using radiocarbon as a natural tracer. We have shown, for example, that ebullition of CH4 is dominated by recently fixed C, but a significant fraction of CH4 in bubbles is derived from old C released during thaw. The APEX time series datasets are being used in a variety of modeling studies, from small-scale soil pore and microbial controls on gas production and transport to regional scale assessments of how carbon cycle feedbacks to climate vary with wetland type and abundance.

Atypical soil hardening during the Tohoku earthquake of March 11, 2011 ( M w = 9.0)

NASA Astrophysics Data System (ADS)

Pavlenko, O. V.

2017-10-01

Based on the records of KiK-net vertical arrays, models of soil behavior down to depths of 100-200 m in the near-fault zones during the Tohoku earthquake are examined. In contrast to the regular pattern observed during strong earthquakes, soft soils have not broadly demonstrated nonlinear behavior, or a reduction (with the onset of strong motions) and recovery (after strong motions finished) of the shear modulus in soil layers. At the stations where anomalously high peak ground accelerations were recorded (PGA > 1g), the values of the shear modulus in soil layers increased with the onset of strong motions and reached a maximum when motions were the most intensive, which indicated hardening of soils. Soil behavior was close to linear, here. The values of the shear moduli decrease along with a decrease in intensity of strong ground motions, and at soft soil stations, this was accompanied by a stepwise decrease in the frequency of motion.

Nonlinear soil parameter effects on dynamic embedment of offshore pipeline on soft clay

NASA Astrophysics Data System (ADS)

Yu, Su Young; Choi, Han Suk; Lee, Seung Keon; Park, Kyu-Sik; Kim, Do Kyun

2015-06-01

In this paper, the effects of nonlinear soft clay on dynamic embedment of offshore pipeline were investigated. Seabed embedment by pipe-soil interactions has impacts on the structural boundary conditions for various subsea structures such as pipeline, riser, pile, and many other systems. A number of studies have been performed to estimate real soil behavior, but their estimation of seabed embedment has not been fully identified and there are still many uncertainties. In this regards, comparison of embedment between field survey and existing empirical models has been performed to identify uncertainties and investigate the effect of nonlinear soil parameter on dynamic embedment. From the comparison, it is found that the dynamic embedment with installation effects based on nonlinear soil model have an influence on seabed embedment. Therefore, the pipe embedment under dynamic condition by nonlinear parameters of soil models was investigated by Dynamic Embedment Factor (DEF) concept, which is defined as the ratio of the dynamic and static embedment of pipeline, in order to overcome the gap between field embedment and currently used empirical and numerical formula. Although DEF through various researches is suggested, its range is too wide and it does not consider dynamic laying effect. It is difficult to find critical parameters that are affecting to the embedment result. Therefore, the study on dynamic embedment factor by soft clay parameters of nonlinear soil model was conducted and the sensitivity analyses about parameters of nonlinear soil model were performed as well. The tendency on dynamic embedment factor was found by conducting numerical analyses using OrcaFlex software. It is found that DEF was influenced by shear strength gradient than other factors. The obtained results will be useful to understand the pipe embedment on soft clay seabed for applying offshore pipeline designs such as on-bottom stability and free span analyses.

Effects of Particle Size on the Shear Behavior of Coarse Grained Soils Reinforced with Geogrid.

PubMed

Kim, Daehyeon; Ha, Sungwoo

2014-02-07

In order to design civil structures that are supported by soils, the shear strength parameters of soils are required. Due to the large particle size of coarse-grained soils, large direct shear tests should be performed. In this study, large direct shear tests on three types of coarse grained soils (4.5 mm, 7.9 mm, and 15.9 mm) were performed to evaluate the effects of particle size on the shear behavior of coarse grained soils with/without geogrid reinforcements. Based on the direct shear test results, it was found that, in the case of no-reinforcement, the larger the maximum particle size became, the larger the friction angle was. Compared with the no-reinforcement case, the cases reinforced with either soft geogrid or stiff geogrid have smaller friction angles. The cohesion of the soil reinforced with stiff geogrid was larger than that of the soil reinforced with soft geogrid. The difference in the shear strength occurs because the case with a stiff geogrid has more soil to geogrid contact area, leading to the reduction in interlocking between soil particles.

Use of Lightweight Cellular Mats to Reduce the Settlement of Structure on Soft Soil

NASA Astrophysics Data System (ADS)

Ganasan, R.; Lim, A. J. M. S.; Wijeyesekera, D. C.

2016-07-01

Construction of structures on soft soils gives rise to some difficulties in Malaysia and other country especially in settlement both in short and long term. The focus of this research is to minimize the differential and non-uniform settlement on peat soil with the use of an innovative cellular mat. The behaviour and performance of the lightweight geo-material (in block form) is critically investigated and in particular the use as a fill in embankment on soft ground. Hemic peat soil, sponge and innovative cellular mat will be used as the main material in this study. The monitoring in settlement behavior from this part of research will be done as laboratory testing only. The uneven settlement in this problem was uniquely monitored photographically using spot markers. In the end of the research, it is seen that the innovative cellular mat has reduce the excessive and differential settlement up to 50% compare to flexible and rigid foundations. This had improve the stiffness of soils as well as the porous contain in cellular structure which help in allowing water/moisture to flow through in or out thus resulting in prevent the condition of floating.

Black willow dominates baldcypress-tupelo swamp eight years after clear cutting

Treesearch

Peter H. Allen

1962-01-01

Our knowledge of successional relations in tidewater river swamps is scant. In an effort to increase our knowledge, the vegetation in a virgin stand of baldcypress (Taxodium distichum), swamp tupelo (Nyssa sylvatica var. biflora), and water tupelo (N. aquatica) was compared with the new growth...

77 FR 72737 - Drawbridge Operation Regulations; Atlantic Intracoastal Waterway (Alternate Route), Dismal Swamp...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-06

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 [Docket No. USCG-2012-1021] Drawbridge Operation Regulations; Atlantic Intracoastal Waterway (Alternate Route), Dismal Swamp Canal, South Mills, NC... (Alternate Route), Dismal Swamp Canal, South Mills, NC. The deviation restricts the operation of the draw...

Jen Gustetic visits Swamp Works

NASA Image and Video Library

2016-10-28

Jenn Gustetic, NASA's Small Business Innovation Research Program executive, talks with Rob Mueller, senior technologist and co-founder of Kennedy Space Center's Swamp Works. Gustetic met team members and viewed many of the pioneering technologies and innovations in development at Kennedy. Swamp Works is a hands-on, lean development environment for innovation following the philosophies pioneered in Kelly Johnson's Skunk Works and Werner von Braun's development shops. The Swamp Works establishes rapid, innovative and cost-effective exploration mission solutions through a highly collaborative, "no walls" approach, leveraging partnerships across NASA, industry and academia.

Micropetrographic characteristics of peats from modern coal-forming environments in Okefenokee Swamp, Georgia and Albemarle-Pamlico Peninsular Swamps, North Carolina

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

Corvinus, D.A.

1982-01-01

The Okefenokee Swamp, over 400,000 acres, is a swamp-marsh complex dominated by Taxodium-swamp vegetaion on its west side and Nymphaea-marsh vegetation onits east side. The Albemarle-Pamlico Peninsular Swamps primarily support a pocosin-bay vegetation. The Taxodium-dominated peats of the Okefenokee are more similar botanically to the Albemarle-Pamlico bay peats than are the Okefenokee Nymphaea-dominated peats. Some petrographic characteristics are common to all three peat types. The majority of cell walls in the peat exhibit colors (yellow to orange to red) which they did not display in their living state. This is believed to be from impregnation by the various cell fillingsmore » present in the peats. Unoxidized fragmented (granular) material in all three peat types usually occurs in larger amounts than oxidized (darkened) material. In Taxodium-dominated and bay peats the fragmented matrix is also usually more prevalent than the preserved material (intact cell walls and cell fillings). On the other hand, preserved material is most common in Nymphaea-dominated peats. It is believed that the majority of fragmented material is derived from the surface litter and that swamp vegetation contributes more surface litter than does marsh vegetation.« less

[Biomass distribution patterns of Alnus hirsuta and Betula platyphylla-swamp ecotone communities in Changbai Mountains].

PubMed

Mu, Changcheng; Wan, Shucheng; Su, Ping; Song, Hongwen; Sun, Zhihu

2004-12-01

In order to reveal the growth patterns of dominant tree species and the distribution patterns of community biomass along the horizontal environmental gradients or among the vertical layers of communities in Changbai Mountains, this paper studied the biomass distribution patterns of Alnus hirsuta-swamp and Betula platyphylla-swamp ecotone communities. The results showed that there were some differences in growth rate and in adaptability to habitats between A. hirsuta and B. platyphylla. In the wetland habitats of the ecotone, A. hirsuta grew 1-2 times faster than B. platyphylla, but along the gradient from swamp to forest, it grew slowly, while B. platyphylla grew fast. Therefore, A. hirsuta was a favorite tree species in wetland habitats. The distribution pattern of organ biomass was similar between A. hirsute and B. platyphylla, the trunk being 1/2, tree root 1/4, branch 1/10, bark 1.5/20, and leaf 1/20. The vertical distribution pattern of biomass was also similar between A. hirsute-swamp and B. platyphylla-swamp ecotone communities, the tree, shrub, and herbage layer accounted for 87%-90%, 7%-9%, and 2%-3%, respectively in the whole ecotone communities. The community biomass increased linearly from swamp to forest with the change of environment factors.

Rehabilitation of Seven (7) Hydrocarbon Contaminated Sites in a Brackish Water/Lagoon Environment in South Trinidad

NASA Astrophysics Data System (ADS)

Mohammed, Avryl; Ramnath, Kelvin; Dyal, Shyam; Lalla, Francesca; Roopchand, Jaipersad

2007-12-01

The Petroleum Company of Trinidad and Tobago Limited operates in a wide diversity of tropical habitats in South Trinidad one of which is a brackish water environment known as the Godineau Swamp. Historically this field was operated by predecessor multinational companies, who at that time employed operational practices based on the absence of legal requirements, that were not environmentally considerate. Following a detailed environmental audit of the field (also known as the Oropouche Field), seven (7) contaminated sites were found, that presented a risk to the lagoon and its associated mangrove swamp ecology. Remediation of the seven (7) sites was done in two (2) phases; phase 1 being sampling and characterization of the waste inclusive of migration and phase 2 the actual on-site soil remediation. Phase 1 conducted during the period December 2004 to February 2005, indicated a total of 19,484 m3 of contaminated material with TPH being the main contaminant. The average concentration of TPH was 3.25%. Phase 2 remediation was initiated in October 2005 and involved the following three (3) aspects to achieve a TPH concentration of less than 1%: ▪ Preparation of waste remediation sites adjacent to contaminated sites and excavation and spreading onto cells ▪ Bioremediation onsite using naturally occurring bacteria and rototilling ▪ Rehabilitation and closure of the site following accepted lab results. The benefits of conducting this project in the petroleum industry are to ensure compliance to the national Sensitive Areas Rules and Draft Waste Management Rules, conformance to ISO 14001 Certification requirements and conservation of biodiversity in the mangrove swamp.

Clonal growth strategy, diversity and structure: A spatiotemporal response to sedimentation in tropical Cyperus papyrus swamps.

PubMed

Geremew, Addisie; Stiers, Iris; Sierens, Tim; Kefalew, Alemayehu; Triest, Ludwig

2018-01-01

Land degradation and soil erosion in the upper catchments of tropical lakes fringed by papyrus vegetation can result in a sediment load gradient from land to lakeward. Understanding the dynamics of clonal modules (ramets and genets) and growth strategies of plants on such a gradient in both space and time is critical for exploring a species adaptation and processes regulating population structure and differentiation. We assessed the spatial and temporal dynamics in clonal growth, diversity, and structure of an emergent macrophyte, Cyperus papyrus (papyrus), in response to two contrasting sedimentation regimes by combining morphological traits and genotype data using 20 microsatellite markers. A total of 636 ramets from six permanent plots (18 x 30 m) in three Ethiopian papyrus swamps, each with discrete sedimentation regimes (high vs. low) were sampled for two years. We found that ramets under the high sedimentation regime (HSR) were significantly clumped and denser than the sparse and spreading ramets under the low sedimentation regime (LSR). The HSR resulted in significantly different ramets with short culm height and girth diameter as compared to the LSR. These results indicated that C. papyrus ameliorates the effect of sedimentation by shifting clonal growth strategy from guerrilla (in LSR) to phalanx (in HSR). Clonal richness, size, dominance, and clonal subrange differed significantly between sediment regimes and studied time periods. Each swamp under HSR revealed a significantly high clonal richness (R = 0.80) as compared to the LSR (R = 0.48). Such discrepancy in clonal richness reflected the occurrence of initial and repeated seedling recruitment strategies as a response to different sedimentation regimes. Overall, our spatial and short-term temporal observations highlighted that HSR enhances clonal richness and decreases clonal subrange owing to repeated seedling recruitment and genets turnover.

Clonal growth strategy, diversity and structure: A spatiotemporal response to sedimentation in tropical Cyperus papyrus swamps

PubMed Central

Stiers, Iris; Sierens, Tim; Kefalew, Alemayehu; Triest, Ludwig

2018-01-01

Land degradation and soil erosion in the upper catchments of tropical lakes fringed by papyrus vegetation can result in a sediment load gradient from land to lakeward. Understanding the dynamics of clonal modules (ramets and genets) and growth strategies of plants on such a gradient in both space and time is critical for exploring a species adaptation and processes regulating population structure and differentiation. We assessed the spatial and temporal dynamics in clonal growth, diversity, and structure of an emergent macrophyte, Cyperus papyrus (papyrus), in response to two contrasting sedimentation regimes by combining morphological traits and genotype data using 20 microsatellite markers. A total of 636 ramets from six permanent plots (18 x 30 m) in three Ethiopian papyrus swamps, each with discrete sedimentation regimes (high vs. low) were sampled for two years. We found that ramets under the high sedimentation regime (HSR) were significantly clumped and denser than the sparse and spreading ramets under the low sedimentation regime (LSR). The HSR resulted in significantly different ramets with short culm height and girth diameter as compared to the LSR. These results indicated that C. papyrus ameliorates the effect of sedimentation by shifting clonal growth strategy from guerrilla (in LSR) to phalanx (in HSR). Clonal richness, size, dominance, and clonal subrange differed significantly between sediment regimes and studied time periods. Each swamp under HSR revealed a significantly high clonal richness (R = 0.80) as compared to the LSR (R = 0.48). Such discrepancy in clonal richness reflected the occurrence of initial and repeated seedling recruitment strategies as a response to different sedimentation regimes. Overall, our spatial and short-term temporal observations highlighted that HSR enhances clonal richness and decreases clonal subrange owing to repeated seedling recruitment and genets turnover. PMID:29338034

Drier Forest Composition Associated with Hydrologic Change in the Apalachicola River, Florida

USGS Publications Warehouse

Darst, Melanie R.; Light, Helen M.

2008-01-01

Forests of the Apalachicola River floodplain had shorter flood durations, were drier in composition, and had 17 percent fewer trees in 2004 than in 1976. The change to drier forest composition is expected to continue for at least 80 more years. Floodplain drying was caused by large declines in river levels resulting from erosion of the river channel after 1954 and from decreased flows in spring and summer months since the 1970s. Water-level declines have been greatest at low and medium flows, which are the most common flows (occurring about 80 percent of the time). Water levels have remained relatively unchanged during large floods which continue to occur about three times per decade. A study conducted by the U.S. Geological Survey compared temporal changes in hydrologic conditions, forest composition, forest characteristics, and individual species of trees, as well as estimated the potential for change in composition of floodplain forests in the nontidal reach of the Apalachicola River. The study was conducted with the cooperation of the Florida Department of Environmental Protection and the Northwest Florida Water Management District. Forest composition and field observations from studies conducted in 1976-1984 (termed '1976 data') were used as baseline data for comparison with data from plots sampled in 2004-2006 ('2004 data'). Flood durations were shorter in all periods subsequent to 1923-1976. The periods of record used to calculate flood durations for forest data were subsets of the complete record available (1923-2004). At sampled plots in all forest types and reaches combined, flood durations changed an average of more than 70 percent toward the baseline flood duration of the next drier forest type. For all forest types, changes in flood durations toward the next drier type were greatest in the upper reach (95.9 percent) and least in the lower reach (42.0 percent). All forests are expected to be 38.2 percent drier in species composition by 2085, the year when the median age of surviving 2004 subcanopy trees will reach the median age (99 years) of the 2004 large canopy trees. The change will be greatest for forests in the upper reach (45.0 percent). Forest composition changes from pre-1954 to 2085 were calculated using Floodplain Indices from 1976 and 2004 tree-size classes and replicate plots. Species composition in high bottomland hardwood forests is expected to continue to change, and some low bottomland hardwood forests are expected to become high bottomland hardwood forests. Organisms associated with floodplain forests will be affected by the changes in tree species, which will alter the timing of leaf-out, fruiting, and leaf-drop, the types of fruit and debris produced, and soil chemistry. Swamps will contain more bottomland hardwood species, but will also have an overall loss of tree density. The density of trees in swamps significantly decreased by 37 percent from 1976 to 2004. Of the estimated 4.3 million (17 percent) fewer trees that existed in the nontidal floodplain in 2004 than in 1976, 3.3 million trees belonged to four swamp species: popash, Ogeechee tupelo, water tupelo, and bald cypress. Water tupelo, the most important tree in the nontidal floodplain in terms of basal area and density, has declined in number of trees by nearly 20 percent since 1976. Ogeechee tupelo, the species valuable to the tupelo honey industry, has declined in number of trees by at least 44 percent. Greater hydrologic variability in recent years may be the reason swamps have had a large decrease in tree density. Drier conditions are detrimental for the growth of swamp species, and periodic large floods kill invading bottomland hardwood trees. The loss of canopy density in swamps may result in the swamp floor being exposed to more light with an increase in the amount of ground cover present, which in turn, would reduce tree replacement. The microclimate of the swamp floor would become wa

Soft Soil Mobility

DTIC Science & Technology

2016-02-11

Wind speed ± 2 knots (kts), 3 km/hr, 1 meter per second (m/s), or ± 5% of reading (whichever is higher) Wind direction ± 7 degrees NOTE: Values...longitudinal sand grades are located in an alluvial plain that lies next to Highway 95. The course material is, soft, loose, dry, wind sorted beach...particles. These soils are easily moved by wind action and tend to build extensive low dunes. The sand dynamometer terrain is described as sandy

Multi-Terrain Impact Testing and Simulation of a Composite Energy Absorbing Fuselage Section

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.; Lyle, Karen H.; Sparks, Chad E.; Sareen, Ashish K.

2007-01-01

Comparisons of the impact performance of a 5-ft diameter crashworthy composite fuselage section were investigated for hard surface, soft soil, and water impacts. The fuselage concept, which was originally designed for impacts onto a hard surface only, consisted of a stiff upper cabin, load bearing floor, and an energy absorbing subfloor. Vertical drop tests were performed at 25-ft/s onto concrete, soft-soil, and water at NASA Langley Research Center. Comparisons of the peak acceleration values, pulse durations, and onset rates were evaluated for each test at specific locations on the fuselage. In addition to comparisons of the experimental results, dynamic finite element models were developed to simulate each impact condition. Once validated, these models can be used to evaluate the dynamic behavior of subfloor components for improved crash protection for hard surface, soft soil, and water impacts.

Multi-Terrain Impact Testing and Simulation of a Composite Energy Absorbing Fuselage Section

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Lyle, Karen H.; Sparks, Chad E.; Sareen, Ashish K.

2004-01-01

Comparisons of the impact performance of a 5-ft diameter crashworthy composite fuselage section were investigated for hard surface, soft soil, and water impacts. The fuselage concept, which was originally designed for impacts onto a hard surface only, consisted of a stiff upper cabin, load bearing floor, and an energy absorbing subfloor. Vertical drop tests were performed at 25-ft/s onto concrete, soft-soil, and water at NASA Langley Research Center. Comparisons of the peak acceleration values, pulse durations, and onset rates were evaluated for each test at specific locations on the fuselage. In addition to comparisons of the experimental results, dynamic finite element models were developed to simulate each impact condition. Once validated, these models can be used to evaluate the dynamic behavior of subfloor components for improved crash protection for hard surface, soft soil, and water impacts.

Food swamps and food deserts in Baltimore City, MD, USA: associations with dietary behaviours among urban adolescent girls.

PubMed

Hager, Erin R; Cockerham, Alexandra; O'Reilly, Nicole; Harrington, Donna; Harding, James; Hurley, Kristen M; Black, Maureen M

2017-10-01

To determine whether living in a food swamp (≥4 corner stores within 0·40 km (0·25 miles) of home) or a food desert (generally, no supermarket or access to healthy foods) is associated with consumption of snacks/desserts or fruits/vegetables, and if neighbourhood-level socio-economic status (SES) confounds relationships. Cross-sectional. Assessments included diet (Youth/Adolescent FFQ, skewed dietary variables normalized) and measured height/weight (BMI-for-age percentiles/Z-scores calculated). A geographic information system geocoded home addresses and mapped food deserts/food swamps. Associations examined using multiple linear regression (MLR) models adjusting for age and BMI-for-age Z-score. Baltimore City, MD, USA. Early adolescent girls (6th/7th grade, n 634; mean age 12·1 years; 90·7 % African American; 52·4 % overweight/obese), recruited from twenty-two urban, low-income schools. Girls' consumption of fruit, vegetables and snacks/desserts: 1·2, 1·7 and 3·4 servings/d, respectively. Girls' food environment: 10·4 % food desert only, 19·1 % food swamp only, 16·1 % both food desert/swamp and 54·4 % neither food desert/swamp. Average median neighbourhood-level household income: $US 35 298. In MLR models, girls living in both food deserts/swamps consumed additional servings of snacks/desserts v. girls living in neither (β=0·13, P=0·029; 3·8 v. 3·2 servings/d). Specifically, girls living in food swamps consumed more snacks/desserts than girls who did not (β=0·16, P=0·003; 3·7 v. 3·1 servings/d), with no confounding effect of neighbourhood-level SES. No associations were identified with food deserts or consumption of fruits/vegetables. Early adolescent girls living in food swamps consumed more snacks/desserts than girls not living in food swamps. Dietary interventions should consider the built environment/food access when addressing adolescent dietary behaviours.

Test Rover Sinks into Prepared Soil

NASA Image and Video Library

2009-06-30

While a test rover rolls off a plywood surface into a prepared bed of soft soil, rover team members Colette Lohr left and Kim Lichtenberg center eye the wheels digging into the soil and Paolo Bellutta enters the next driving command.

The effects of past climate variability on fire and vegetation in the cerrãdo savanna ecosystem of the Huanchaca Mesetta, Noel Kempff Mercado National Park, NE Bolivia

NASA Astrophysics Data System (ADS)

Maezumi, S. Y.; Power, M. J.; Mayle, F. E.; McLauchlan, K.; Iriarte, J.

2015-01-01

Cerrãdo savannas have the greatest fire activity of all major global land-cover types and play a significant role in the global carbon cycle. During the 21st century, temperatures are predicted to increase by ~ 3 °C coupled with a precipitation decrease of ~ 20%. Although these conditions could potentially intensify drought stress, it is unknown how that might alter vegetation composition and fire regimes. To assess how Neotropical savannas responded to past climate changes, a 14 500 year, high-resolution, sedimentary record from Huanchaca Mesetta, a palm swamp located in the cerrãdo savanna in northeastern Bolivia, was analyzed for phytoliths, stable isotopes and charcoal. A non-analogue, cold-adapted vegetation community dominated the Late Glacial-Early Holocene period (14 500-9000 ka), that included trees and C3 Pooideae and C4 Panicoideae grasses. The Late Glacial vegetation was fire sensitive and fire activity during this period was low, likely responding to fuel availability and limitation. Although similar vegetation characterized the Early Holocene, the warming conditions associated with the onset of the Holocene led to an initial increase in fire activity. Huanchaca Mesetta became increasingly fire-dependent during the Middle Holocene with the expansion of C4 fire adapted grasses. However, as warm, dry conditions, characterized by increased length and severity of the dry season, continued, fuel availability decreased. The establishment of the modern palm swamp vegetation occurred at 5000 cal yr BP. Edaphic factors are the first order control on vegetation on the rocky quartzite mesetta. Where soils are sufficiently thick, climate is the second order control of vegetation on the mesetta. The presence of the modern palm swamp is attributed to two factors: (1) increased precipitation that increased water table levels, and (2) decreased frequency and duration of surazos leading to increased temperature minima. Natural (soil, climate, fire) drivers rather than anthropogenic drivers control the vegetation and fire activity at Huanchaca Mesetta. Thus the cerrãdo savanna ecosystem of the Huanchaca Plateau has exhibited ecosystem resilience to major climatic changes in both temperature and precipitation since the Late Glacial period.

Age, extent and carbon storage of the central Congo Basin peatland complex.

PubMed

Dargie, Greta C; Lewis, Simon L; Lawson, Ian T; Mitchard, Edward T A; Page, Susan E; Bocko, Yannick E; Ifo, Suspense A

2017-02-02

Peatlands are carbon-rich ecosystems that cover just three per cent of Earth's land surface, but store one-third of soil carbon. Peat soils are formed by the build-up of partially decomposed organic matter under waterlogged anoxic conditions. Most peat is found in cool climatic regions where unimpeded decomposition is slower, but deposits are also found under some tropical swamp forests. Here we present field measurements from one of the world's most extensive regions of swamp forest, the Cuvette Centrale depression in the central Congo Basin. We find extensive peat deposits beneath the swamp forest vegetation (peat defined as material with an organic matter content of at least 65 per cent to a depth of at least 0.3 metres). Radiocarbon dates indicate that peat began accumulating from about 10,600 years ago, coincident with the onset of more humid conditions in central Africa at the beginning of the Holocene. The peatlands occupy large interfluvial basins, and seem to be largely rain-fed and ombrotrophic-like (of low nutrient status) systems. Although the peat layer is relatively shallow (with a maximum depth of 5.9 metres and a median depth of 2.0 metres), by combining in situ and remotely sensed data, we estimate the area of peat to be approximately 145,500 square kilometres (95 per cent confidence interval of 131,900-156,400 square kilometres), making the Cuvette Centrale the most extensive peatland complex in the tropics. This area is more than five times the maximum possible area reported for the Congo Basin in a recent synthesis of pantropical peat extent. We estimate that the peatlands store approximately 30.6 petagrams (30.6 × 10 15  grams) of carbon belowground (95 per cent confidence interval of 6.3-46.8 petagrams of carbon)-a quantity that is similar to the above-ground carbon stocks of the tropical forests of the entire Congo Basin. Our result for the Cuvette Centrale increases the best estimate of global tropical peatland carbon stocks by 36 per cent, to 104.7 petagrams of carbon (minimum estimate of 69.6 petagrams of carbon; maximum estimate of 129.8 petagrams of carbon). This stored carbon is vulnerable to land-use change and any future reduction in precipitation.

[Seed germination and seedling survival and growth in swamps dominated by palms Raphia tae- digera (Arecaceae) in Tortuguero plains, Costa Rica].

PubMed

Myers, Ronald L

2013-09-01

In the marshes dominated by palms, seeds face anaerobic substrates and long flooding periods. Some tree species are capable of growing both in flooded swamps and in areas with lower influence of the flood. I studied the potential settlement of various tree species in different macrohabitats in the Tortuguero floodplain using three experiments: (1) Manicaria saccifera and Raphia taedigera seed germination in palm-swamps and forests of slopes; (2) germination of R. taedigera seeds along a microtopographic gradient; and (3) seed germination and seedling height growth of six woody species (Dipteryx oleifera, Pterocarpus officinalis, Prioria copaifera, Pentaclethra macroloba, Carapa guianensis and Crudia acuminata) and two palms (R. taedigera and Manicaria saccifera) under different forest and swamp habitats. In the first experiment, I found that the palms germinated much earlier in the slope forest than in the palm-swamp. In the second experiment, in drier plots (less effect of flooding) germination began earlier than in the more humid plots. In the third experiment, woody species germinated faster than the studied palms, and some species do not tolerate flooded areas (marshes and swamps), so they cannot germinate or survive in them. Other woody species were removed from the slope forest, probably due to seed predators. Based on the presence or absence of these species in the environment of study were divided into: (1) obliged swamp species (R. taedigera and M saccifera), (2) swamp intolerant (D. oleifera), and (3) facultative wetland species (P officinalis, P copaifera, P macroloba, C. guianensis). Crudia acuminata does not seem to follow any of these categories.

Experiment Study on Determination of Surface Area of Finegrained Soils by Mercury Intrusion Porosimetry

NASA Astrophysics Data System (ADS)

Yan, X. Q.; Zhou, C. Y.; Fang, Y. G.; Lin, L. S.

2017-12-01

The specific surface area (SSA) has a great influence on the physical and chemical properties of fine-grained soils. Determination of specific surface area is an important content for fine-grained soils micro-meso analysis and characteristic research. In this paper, mercury intrusion porosimetry (MIP) was adopted to determine the SSA of fine-grained soils including quartz, kaolinite, bentonite and natural Shenzhen soft clay. The test results show that the average values of SSA obtained by MIP are 0.78m2/g, 11.31m2/g, 57.28m2/g and 27.15m2/g respectively for very fine-grained quartz, kaolin, bentonite and natural Shenzhen soft clay, and that it is feasible to apply MIP to obtain the SSA of fine-grained soils through statistical analysis of 97 samples. Through discussion, it is necessary to consider the state of fine-grained soils such as pore ratio when the SSA of fine-grained soils is determined by MIP.

Crash Testing and Simulation of a Cessna 172 Aircraft: Pitch Down Impact Onto Soft Soil

NASA Technical Reports Server (NTRS)

Fasanella, Edwin L.; Jackson, Karen E.

2016-01-01

During the summer of 2015, NASA Langley Research Center conducted three full-scale crash tests of Cessna 172 (C-172) aircraft at the NASA Langley Landing and Impact Research (LandIR) Facility. The first test represented a flare-to-stall emergency or hard landing onto a rigid surface. The second test, which is the focus of this paper, represented a controlled-flight-into-terrain (CFIT) with a nose-down pitch attitude of the aircraft, which impacted onto soft soil. The third test, also conducted onto soil, represented a CFIT with a nose-up pitch attitude of the aircraft, which resulted in a tail strike condition. These three crash tests were performed for the purpose of evaluating the performance of Emergency Locator Transmitters (ELTs) and to generate impact test data for model validation. LS-DYNA finite element models were generated to simulate the three test conditions. This paper describes the model development and presents test-analysis comparisons of acceleration and velocity time-histories, as well as a comparison of the time sequence of events for Test 2 onto soft soil.

Microhabitat Characteristics of sites used by swamp rabbits

Treesearch

Patrick A. Zollner; Winston P. Smith; Leonard A. Brennan

2000-01-01

The swamp rabbit (Sylvilagus aquaticus) is one of the least studied North American lagomorphs; a better understanding of the habitat types it uses will improve management of this species. We studied microhabitat characteristics of sites associated with specific behaviors of the swamp rabbit. During spring-summer (15 April-1 October) and fall-winter (...

43 CFR 2625.0-3 - Authority.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.0-3 Authority. (a) Circular dated Mar. 17, 1896, containing the swamp-land laws and regulations, states: As soon as practicable after the passage of the swamp-land grant of September 28, 1850, viz, on the 21st of...

43 CFR 2625.0-3 - Authority.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.0-3 Authority. (a) Circular dated Mar. 17, 1896, containing the swamp-land laws and regulations, states: As soon as practicable after the passage of the swamp-land grant of September 28, 1850, viz, on the 21st of...

43 CFR 2625.0-3 - Authority.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.0-3 Authority. (a) Circular dated Mar. 17, 1896, containing the swamp-land laws and regulations, states: As soon as practicable after the passage of the swamp-land grant of September 28, 1850, viz, on the 21st of...

43 CFR 2625.0-3 - Authority.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., DEPARTMENT OF THE INTERIOR LAND RESOURCE MANAGEMENT (2000) STATE GRANTS Swamp-land Grants § 2625.0-3 Authority. (a) Circular dated Mar. 17, 1896, containing the swamp-land laws and regulations, states: As soon as practicable after the passage of the swamp-land grant of September 28, 1850, viz, on the 21st of...

Diurnal and Tidal Variation of Temperature and Salinity in the Ponta Rasa Mangrove Swamp, Mozambique

NASA Astrophysics Data System (ADS)

Hoguane, A. M.; Hill, A. E.; Simpson, J. H.; Bowers, D. G.

1999-08-01

Measurements of hydrographic conditions in the Ponta Rasa tidal mangrove swamp, Inhaca Island, Mozambique were made in August-October 1994 during the winter dry season. The Ponta Rasa swamp/creek is tidally choked on account of the narrow channel that connects it to Maputo Bay and at neap tides, a sill prevents bay water entering the creek system altogether. Temperature variation in the swamp (15-25 °C) was predominantly diurnal with an additional signal due to the tidal advection of bay waters. There is no river discharge into Ponta Rasa and during the observation period, there was no significant rainfall. The mean salinity in the swamp ( c. 38) was controlled by evaporation and transpiration by mangroves and an overall evapotranspiration rate of 0·5 cm day -1was estimated from a steady salt balance. Salinity variation ( c. 2) was predominantly due to semi-diurnal tidal advection of lower salinity Maputo Bay water into the swamp/creek. A model which incorporates tidal dynamics coupled to heat and salt balance equations reproduces many of the observed features of the system.

The hydrological function of upland swamps in eastern Australia: The role of geomorphic condition in regulating water storage and discharge

NASA Astrophysics Data System (ADS)

Cowley, Kirsten L.; Fryirs, Kirstie A.; Hose, Grant C.

2018-06-01

Temperate Highland Peat Swamps on Sandstone (THPSS) are a type of wetland found in low-order streams on the plateaus of eastern Australia. They are sediment and organic matter accumulation zones, which combined with a climate of high rainfall and low evaporation function as water storage systems. Changes to the geomorphic structure of these systems via incision and channelisation can have profound impacts on their hydrological function. The aim of this study was to develop an understanding of how changes to the geomorphic structure of these systems alter their hydrological function, measured as changes and variability in swamp water table levels and discharge. We monitored the water table levels and discharges of three intact and three channelised THPSS in the Blue Mountains between March 2015 and June 2016. We found that water levels in intact swamps were largely stable over the monitoring period. Water levels rose only in high rainfall events, returned quickly to antecedent levels after rain, and drawdown during dry periods was not significant. In contrast, the water table levels in channelised THPSS were highly variable. Water levels rose quickly after almost all rainfall events and declined significantly during dry periods. Discharge also showed marked differences with the channelised THPSS discharging 13 times more water than intact swamps, even during dry periods. Channelised THPSS also had flashier storm hydrographs than intact swamps. These results have profound implications for the capacity of these swamps to act as water storage reservoirs in the headwaters of catchments and for their ability to maintain base flow to downstream catchments during dry times. Changes to geomorphic structure and hydrological function also have important implications for a range of other swamp functions such as carbon storage, emission and exports, contaminant sorption, downstream water quality and biodiversity, as well as the overall fate of these swamps under a changing climate.

[Amphibians and reptiles in the swamps dominated by the palm Raphia taedigera (Arecaceae) in northeastern Costa Rica].

PubMed

Bonilla-Murillo, Fabian; Beneyto, Davinia; Sasa, Mahmood

2013-09-01

The herpetofauna that inhabits Caribbean Costa Rica has received considerable attention in the last two decades. This assemblage includes a total of 141 species of reptiles and 95 amphibians mostly distributed in tropical wet and moist lowland forests. While most information available came from primary and secondary forest sites, little is known about the amphibians and reptiles that inhabit more open habitats, such as wetlands and swamps. For instances, swaps dominated by the yolillo palm Raphia taedigera extend through much of the northeastern Caribbean coast of Costa Rica and eastern Nicaragua, but information about the herpetological community that uses such environments remains practically unknown. This situation reflects the little research conducted in such inhospitable environments. Here, we report the results of an intensive survey conducted to assess the herpetological community that inhabit R. taedigera palm-swamps. A total of 14 species of amphibians and 17 of reptiles have been recorded from these swamps. Amphibians and reptiles that inhabit yolillo swamps have wide distributions along much of Middle America and are considered common species throughout their range. In general, yolillo swamps are poor environments for herpetofauna: richness of reptiles and amphibians is almost two times higher in the adjacent forest than in the palm dominated swamps. Furthermore, most species observed in this swamps can be considered habitat generalists that are well adapted to the extreme conditions imposed by the changes in hydroperiods, reduce understory cover, low tree diversity and simple forest architecture of these environments. Despite similarities in the herpetofauna, it is clear that not all forest species use yolillo habitat, a characteristic that is discussed in terms of physical stress driven by the prolonged hydroperiod and reduced leaflitter in the ground, as these features drive habitat structure and herpetofaunal complexity. Our list of species using yolillo swamps is not definitive, and is likely to grow as more studies are conducted in this unexplored environment.

Rheological properties of soil: a review

NASA Astrophysics Data System (ADS)

Zhu, Guangli; Zhu, Long; Yu, Chao

2017-05-01

Recently rheological methods have been applied to investigate the mechanical properties of soil micro-structure. Rheological techniques have a number of quantitative physically based measurements and offer a better understanding of how soil micro-structure behaves when subject to stress. Rheological material is refers to deformation properties similar to the solid and flow properties similar to the liquid of bound water and colloidal substances under stress. Soil rheology is divided into fluid rheology and plasticity rheology. Fluid rheology is produced by rheological material. Plasticity rheology mainly refers to the sliding and peristaltic between soil solid particles under shear stress. It is generally believed that the soft soil rheology mainly belongs to fluid rheology, while the rheology of sand and other coarse grained soil mainly belongs to plasticity rheology. Thus, rheology mechanisms of soft soil and sand are different. This paper introduces the methods of the research progress on the rheology of soil, in the soil rheological mechanism, rheological model and rheological numerical aspects of the research at home and abroad were summarized and analysed, discussed the problems existed in related research, and puts forward some suggestions for the future study on the rheology of soil.

Vertical patterns and controls of soil nutrients in alpine grassland: Implications for nutrient uptake.

PubMed

Tian, Liming; Zhao, Lin; Wu, Xiaodong; Fang, Hongbing; Zhao, Yonghua; Yue, Guangyang; Liu, Guimin; Chen, Hao

2017-12-31

Vertical patterns and determinants of soil nutrients are critical to understand nutrient cycling in high-altitude ecosystems; however, they remain poorly understood in the alpine grassland due to lack of systematic field observations. In this study, we examined vertical distributions of soil nutrients and their influencing factors within the upper 1m of soil, using data of 68 soil profiles surveyed in the alpine grassland of the eastern Qinghai-Tibet Plateau. Soil organic carbon (SOC) and total nitrogen (TN) stocks decreased with depth in both alpine meadow (AM) and alpine steppe (AS), but remain constant along the soil profile in alpine swamp meadow (ASM). Total phosphorus, Ca 2+ , and Mg 2+ stocks slightly increased with depth in ASM. K + stock decreased with depth, while Na + stock increased slightly with depth among different vegetation types; however, SO 4 2- and Cl - stocks remained relatively uniform throughout different depth intervals in the alpine grassland. Except for SOC and TN, soil nutrient stocks in the top 20cm soils were significantly lower in ASM compared to those in AM and AS. Correlation analyses showed that SOC and TN stocks in the alpine grassland positively correlated with vegetation coverage, soil moisture, clay content, and silt content, while they negatively related to sand content and soil pH. However, base cation stocks revealed contrary relationships with those environmental variables compared to SOC and TN stocks. These correlations varied between vegetation types. In addition, no significant relationship was detected between topographic factors and soil nutrients. Our findings suggest that plant cycling and soil moisture primarily control vertical distributions of soil nutrients (e.g. K) in the alpine grassland and highlight that vegetation types in high-altitude permafrost regions significantly affect soil nutrients. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydropodelogy From the Pedon to the Landscape: Challenges and Accomplishments in the National Cooperative Soil Survey

NASA Astrophysics Data System (ADS)

Hammer, D.; Richardson, J.; Hempel, J.; Market, P.

2005-12-01

American pedology has focused on the National Cooperative Soil Survey. Primary responsibility rests with the U.S. Department of Agriculture. The primary goals, are legislatively mandated, are to map the country's soils, make interpretations, provide information to clients, maintain and market the soil survey. The first goal is near completion and focus is shifting to the other three. Concomitantly, American pedological science is being impacted by several conditions: technological advances; land use changes at unprecedented scales and magnitudes; a burgeoning population increasingly "separated" from the land; and a major emphasis in universities upon biological ("life") sciences at the DNA scale - as if soil, nutrients and water are not life essentials. Effects of the Flood of 1993 and Hurricane Katrina suggest that humans do not understand earth/climate interactions, particularly climatic extremes. Pedologists know the focus on soil classification and mapping was at the expense of understanding processes. Hydropedology is a holistic approach to understanding soil and geomorphic process in order to predict the impacts of perturbations. Water movement on and in the soil is the primary mechanism of distributing and altering sediments and chemicals (pedogenesis), and depends for its success upon understanding that the soil profile is the record of developmental history at that landscape site. Hydropedologists believe soil scientists can use pedons (point data) from appropriate locations from flownets in complex landscapes to extrapolate processes. This is the "pedotransfer function" concept. Technological advances are coupled with the existing soil survey information to create important soil-landscape interpretations at a variety of scales. Early results have been very successful. Quantification of soil systems can be classified broadly into three categories; hard data, soft data and tacit knowledge. "Hard data" are measured numbers, and include such attributes as pH, texture, cation exchange capacity and event-specific rainfall. "Soft data" include soil maps, SSURGO data and climate maps. Soft data are combinations of observations, measurements and inferences that produce maps and models at various scales. "Tacit knowledge" is human understanding that results from focused experience within a system. A skilled soil scientist with tacit knowledge specific to a particular region can combination hard and soft data to develop important and useful interpretations and predictions. Illustrations from natural and urban settings will be provided. Soils and climate are temporally and spatially variable at all scales. Soil systems respond differently to different climates and perturbations. For example, the recent pluvial period in the Prairie Pothole region is changing surface soil sodium concentrations and locations and sizes of discharge wetlands. This is a relatively short-term response to a regional climate shift. Climatic shift in Oxisol landscapes will have little effect on soil cations. To optimize soil interpretations, focus must be on quantifying region-specific "dynamic" soil, geomorphic and climatic attributes. Recognizing these needs, the National Cooperative Soil Survey will develop regional watershed projects that focus on quantifying soil-water relationships that can be used at a variety of scales.

Isolation of heat-tolerant myoglobin from Asian swamp eel Monopterus albus.

PubMed

Chotichayapong, Chatrachatchaya; Wiengsamut, Kittipong; Chanthai, Saksit; Sattayasai, Nison; Tamiya, Toru; Kanzawa, Nobuyuki; Tsuchiya, Takahide

2012-10-01

Myoglobin from Asian swamp eel Monopterus albus was purified from fish muscle using salt fractionation followed by column chromatography and molecular filtration. The purified Mb of 0.68 mg/g wet weight of muscle was determined for its molecular mass by MALDI-TOF-MS to be 15,525.18 Da. Using isoelectric focusing technique, the purified Mb showed two derivatives with pI of 6.40 and 7.12. Six peptide fragments of this protein identified by LC-MS/MS were homologous to Mbs of sea raven Hemitripterus americanus, yellowfin tuna Thunnus albacores, blue marlin Makaira nigicans, common carp Cyprinus carpio, and goldfish Carassius auratus. According to the Mb denaturation, the swamp eel Mb had thermal stability higher than walking catfish Clarias batrachus Mb and striped catfish Pangasius hypophthalmus Mb, between 30 and 60 (°)C. For the thermal stability of Mb, the swamp eel Mb showed a biphasic behavior due to the O(2) dissociation and the heme orientation disorder, with the lowest increase in both Kd(f) and Kd(s). The thermal sensitivity of swamp eel Mb was lower than those of the other Mbs for both of fast and slow reaction stages. These results suggest that the swamp eel Mb globin structure is thermally stable, which is consistent with heat-tolerant behavior of the swamp eel particularly in drought habitat.

Seismic velocities and geologic logs from boreholes at three downhole arrays in San Francisco, California

USGS Publications Warehouse

Gibbs, James F.; Fumal, Thomas E.; Borcherdt, Roger D.; Warrick, Richard E.; Liu, Hsi-Ping; Westerlund, Robert E.

1994-01-01

The Loma Prieta earthquake of October 17, 1989 (1704 PST), has reinforced observations made by Wood and others (1908) after the 1906 San Francisco earthquake, that poor ground conditions (soft soil) increase the likelihood of shaking damage to structures. Since 1908 many studies (for example Borcherdt, 1970, Borcherdt and Gibbs, 1976, Borcherdt and Glassmoyer, 1992) have shown that soft soils amplify seismic waves at frequencies that can be damaging to structures. Damage in the City of San Francisco from the Loma Prieta earthquake was concentrated in the Marina District, the Embarcadero, and the China Basin areas. Each of these areas, to some degree, is underlain by soft soil deposits. These concentrations of damage raise important questions regarding the amplification effects of such deposits at damaging levels of motion. Unfortunately, no strong-motion recordings were obtained in these areas during the Loma Prieta earthquake and only a limited number (< 10) have been obtained on other soft soil sites in the United States. Consequently, important questions exist regarding the response of such deposits during damaging earthquakes, especially questions regarding the nonlinear soil response. Towards developing a data set to address these important questions, borehole strong-motion arrays have been installed at three locations. These arrays consist of groups of wide-dynamic-range pore-pressure transducers and three-component accelerometers, the outputs of which are recorded digitally. The arrays are designed to provide an integrated set of data on ground shaking, liquifaction-induced ground failure, and structural response. This report describes the detailed geologic, seismic, and material-property determinations derived at each of these sites.

The soil carbon/nitrogen ratio and moisture affect microbial community structures in alkaline permafrost-affected soils with different vegetation types on the Tibetan plateau.

PubMed

Zhang, Xinfang; Xu, Shijian; Li, Changming; Zhao, Lin; Feng, Huyuan; Yue, Guangyang; Ren, Zhengwei; Cheng, Guogdong

2014-01-01

In the Tibetan permafrost region, vegetation types and soil properties have been affected by permafrost degradation, but little is known about the corresponding patterns of their soil microbial communities. Thus, we analyzed the effects of vegetation types and their covariant soil properties on bacterial and fungal community structure and membership and bacterial community-level physiological patterns. Pyrosequencing and Biolog EcoPlates were used to analyze 19 permafrost-affected soil samples from four principal vegetation types: swamp meadow (SM), meadow (M), steppe (S) and desert steppe (DS). Proteobacteria, Acidobacteria, Bacteroidetes and Actinobacteria dominated bacterial communities and the main fungal phyla were Ascomycota, Basidiomycota and Mucoromycotina. The ratios of Proteobacteria/Acidobacteria decreased in the order: SM>M>S>DS, whereas the Ascomycota/Basidiomycota ratios increased. The distributions of carbon and nitrogen cycling bacterial genera detected were related to soil properties. The bacterial communities in SM/M soils degraded amines/amino acids very rapidly, while polymers were degraded rapidly by S/DS communities. UniFrac analysis of bacterial communities detected differences among vegetation types. The fungal UniFrac community patterns of SM differed from the others. Redundancy analysis showed that the carbon/nitrogen ratio had the main effect on bacteria community structures and their diversity in alkaline soil, whereas soil moisture was mainly responsible for structuring fungal communities. Thus, microbial communities and their functioning are probably affected by soil environmental change in response to permafrost degradation. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Improvement in engineering properties of soft-soil using cement and lime additives: A case study of southern Vietnam

NASA Astrophysics Data System (ADS)

To-Anh Phan, Vu; Ngoc-Anh Pham, Kha

2018-04-01

This paper presents the experimental results of using two additives to improve natural soft soil properties in southern Vietnam (i.g., cement and cement-lime mixture). The specimens were prepared by compacting method. Firstly, the natural soil was mixed with cement or cement-lime to determine the optimum water contents of various additive contents. Then, optimum water content was used to produce samples to test some engineering properties such as unconfined compressive strength, splitting tensile strength, and Young’s modulus. The specimens were tested by various curing duration of 7, 14, and 28 days. Results indicated that using cement additive is suitable for improvement of soft soil in the local area and cement-soil stabilization can be replaced as the subbase layer of the flexible pavement according to current Vietnamese standard. In addition, a higher cement content has a greater compressive strength as well as tensile strength. Besides, the Young’ modulus has significantly increased with a long-term curing age and more cement content. No evidences of increasing in strength and modulus are found with the cement-lime-soil stabilization. Finally, the best-fit power function is established by the relationships between unconfined compressive strength and splitting tensile strength as well unconfined compressive strength and Young’s Modulus, with the coefficient of determination, R2>0.999.

Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting

Treesearch

Eric A. Nelson; Neil C. Dulohery; Randall K. Kolka; William H. McKee

2000-01-01

The Savannah River swamp, a 3020 ha forested wetland on the floodplain of the Savannah River, USA is located on the Department of Energy's Savannah River site (SRS) near Aiken, SC. Historically, the swamp consisted of approximately 50% bald cypress-water tupelo (Taxodium distichum-Nyssa aquatica) stands, 40% mixed bottomland hardwood stands, and...

Are You Phrog Farming or Helping to Drain the Swamp?

ERIC Educational Resources Information Center

Harvey, Jerry B.

1983-01-01

The difference between phrogfessors and teachers is that phrogfessors train tadpoles in the way of the swamp (i.e., create likenesses of themselves) while teachers produce people and thereby help to drain the swamp. Phrogfessors take responsibility for what their students learn. They believe that if a student does badly, it is the phrogfessor's…

Veneer cutting and drying properties of tupelo

Treesearch

Forest Products Laboratory (U.S.).

1963-01-01

There are three commercially important tupelo species: Water tupelo (Nyssa aquatica), black tupelo (N. sylvatica), and swamp tupelo (N. sylvatica var. biflora). Water tupelo and swamp tupelo, as the names indicate, are water-loving trees and grow principally in the fresh-water swamps and along the edges of streams and ponds in southeastern United States. Black tupelo,...

Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species.

PubMed

Prospere, Kurt; McLaren, Kurt P; Wilson, Byron

2016-10-01

The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species

NASA Astrophysics Data System (ADS)

Prospere, Kurt; McLaren, Kurt P.; Wilson, Byron

2016-10-01

The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

Characteristics and engineering properties of the soft soil layer in highway soil subgrades.

DOT National Transportation Integrated Search

2006-06-01

The objective of this research was to examine the conditions and characteristics of soil subgrades that had been stabilized using mechanical compaction. Goals of the study are to identify and examine the engineering properties and behavior of the ...

Site effect classification based on microtremor data analysis using a concentration-area fractal model

NASA Astrophysics Data System (ADS)

Adib, A.; Afzal, P.; Heydarzadeh, K.

2015-01-01

The aim of this study is to classify the site effect using concentration-area (C-A) fractal model in Meybod city, central Iran, based on microtremor data analysis. Log-log plots of the frequency, amplification and vulnerability index (k-g) indicate a multifractal nature for the parameters in the area. The results obtained from the C-A fractal modelling reveal that proper soil types are located around the central city. The results derived via the fractal modelling were utilized to improve the Nogoshi and Igarashi (1970, 1971) classification results in the Meybod city. The resulting categories are: (1) hard soil and weak rock with frequency of 6.2 to 8 Hz, (2) stiff soil with frequency of about 4.9 to 6.2 Hz, (3) moderately soft soil with the frequency of 2.4 to 4.9 Hz, and (4) soft soil with the frequency lower than 2.4 Hz.

Site effect classification based on microtremor data analysis using concentration-area fractal model

NASA Astrophysics Data System (ADS)

Adib, A.; Afzal, P.; Heydarzadeh, K.

2014-07-01

The aim of this study is to classify the site effect using concentration-area (C-A) fractal model in Meybod city, Central Iran, based on microtremor data analysis. Log-log plots of the frequency, amplification and vulnerability index (k-g) indicate a multifractal nature for the parameters in the area. The results obtained from the C-A fractal modeling reveal that proper soil types are located around the central city. The results derived via the fractal modeling were utilized to improve the Nogoshi's classification results in the Meybod city. The resulted categories are: (1) hard soil and weak rock with frequency of 6.2 to 8 Hz, (2) stiff soil with frequency of about 4.9 to 6.2 Hz, (3) moderately soft soil with the frequency of 2.4 to 4.9 Hz, and (4) soft soil with the frequency lower than 2.4 Hz.

Lateral carbon fluxes and CO2 outgassing from a tropical peat-draining river

NASA Astrophysics Data System (ADS)

Müller, D.; Warneke, T.; Rixen, T.; Müller, M.; Jamahari, S.; Denis, N.; Mujahid, A.; Notholt, J.

2015-07-01

Tropical peatlands play an important role in the global carbon cycle due to their immense carbon storage capacity. However, pristine peat swamp forests are vanishing due to deforestation and peatland degradation, especially in Southeast Asia. CO2 emissions associated with this land use change might not only come from the peat soil directly, but also from peat-draining rivers. So far, though, this has been mere speculation, since there was no data from undisturbed reference sites. We present the first combined assessment of lateral organic carbon fluxes and CO2 outgassing from an undisturbed tropical peat-draining river. Two sampling campaigns were undertaken on the Maludam river in Sarawak, Malaysia. The river catchment is covered by protected peat swamp forest, offering a unique opportunity to study a peat-draining river in its natural state, without any influence from tributaries with different characteristics. The two campaigns yielded consistent results. Dissolved organic carbon (DOC) concentrations ranged between 3222 and 6218 μmol L-1 and accounted for more than 99 % of the total organic carbon (TOC). Radiocarbon dating revealed that the riverine DOC was of recent origin, suggesting that it derives from the top soil layers and surface runoff. We observed strong oxygen depletion, implying high rates of organic matter decomposition and consequently CO2 production. The measured median pCO2 was 7795 and 8400 μatm during the two campaigns, respectively. Overall, we found that only 26 ± 15 % of the carbon was exported by CO2 evasion, while the rest was exported by discharge. CO2 outgassing seemed to be moderated by the short water residence time. Since most Southeast Asian peatlands are located at the coast, this is probably an important limiting factor for CO2 outgassing from most of its peat-draining rivers.

Experimental Research on Creep Characteristics of Nansha Soft Soil

PubMed Central

Luo, Qingzi; Chen, Xiaoping

2014-01-01

A series of tests were performed to investigate the creep characteristics of soil in interactive marine and terrestrial deposit of Pearl River Delta. The secondary consolidation test results show that the influence of consolidation pressure on coefficient of secondary consolidation is conditional, which is decided by the consolidation state. The ratio of coefficient of secondary consolidation and coefficient of compressibility C a/C c is almost a constant, and the value is 0.03. In the shear-box test, the direct sheer creep failure of soil is mainly controlled by shear stress rather than the accumulation of shear strain. The triaxial creep features are closely associated with the drainage conditions, and consolidation can weaken the effect of creep. When the soft soil has triaxial creep damage, the strain rate will increase sharply. PMID:24526925

Experimental research on creep characteristics of Nansha soft soil.

PubMed

Luo, Qingzi; Chen, Xiaoping

2014-01-01

A series of tests were performed to investigate the creep characteristics of soil in interactive marine and terrestrial deposit of Pearl River Delta. The secondary consolidation test results show that the influence of consolidation pressure on coefficient of secondary consolidation is conditional, which is decided by the consolidation state. The ratio of coefficient of secondary consolidation and coefficient of compressibility (Ca/Cc) is almost a constant, and the value is 0.03. In the shear-box test, the direct sheer creep failure of soil is mainly controlled by shear stress rather than the accumulation of shear strain. The triaxial creep features are closely associated with the drainage conditions, and consolidation can weaken the effect of creep. When the soft soil has triaxial creep damage, the strain rate will increase sharply.

Reproduction on cut-over swamplands in the Upper Peninsula of Michigan

Treesearch

Z.A. Zasada

1952-01-01

The 1 ¼ million acres of coniferous swamp forest in the Upper Peninsula of Michigan are important to industry, game management and water conservation. Because there was little knowledge on handling this type, foresters in 1950 began a program of research in swamp forest management. The first project was a survey of recent swamp cuttings. The survey shows that...

Long- and short-term flooding effects on survival and sink-source relationships of swamp-adapted tree species

Treesearch

M.N. Angelov; Shi-Jean S. Sung; R.L. Doong; W.R. Harms; Paul P. Kormanik; C.C. Black

1995-01-01

About 95% of swamp tupelo (Nyssa sylvatica var. biflora (Walt.) Sarg.) And sweetgum (Liquidambar styraciflua L.) seedlings survived continuous root flooding for more than two years, whereas none of the swamp chestnut oak (Quercus michauxii Nutt.) And cherrybark oak (Q. falcata var. pagodifolia Ell.) Seedlings survived one year of flooding.Flooding caused increases in...

Development and application of a spatial hydrology model of Okefenokee Swamp, Georgia

USGS Publications Warehouse

Loftin, C.S.; Kitchens, W.M.; Ansay, N.

2001-01-01

The model described herein was used to assess effects of the Suwannee River sill (a low earthen dam constructed to impound the Suwannee River within the Okefenokee National Wildlife Refuge to eliminate wildfires) on the hydrologic environment of Okefenokee Swamp, Georgia. Developed with Arc/Info Macro Language routines in the GRID environment, the model distributes water in the swamp landscape using precipitation, inflow, evapotranspiration, outflow, and standing water. Water movement direction and rate are determined by the neighborhood topographic gradient, determined using survey grade Global Positioning Systems technology. Model data include flow rates from USGS monitored gauges, precipitation volumes and water levels measured within the swamp, and estimated evapotranspiration volumes spatially modified by vegetation type. Model output in semi-monthly time steps includes water depth, water surface elevation above mean sea level, and movement direction and volume. Model simulations indicate the sill impoundment affects 18 percent of the swamp during high water conditions when wildfires are scarce and has minimal spatial effect (increasing hydroperiods in less than 5 percent of the swamp) during low water and drought conditions when fire occurrence is high but precipitation and inflow volumes are limited.

Experimental Study on Vacuum Dynamic Consolidation Treatment of Soft Soil Foundation

NASA Astrophysics Data System (ADS)

Fu-lai, Ni; Xin, Wen; Xiao-bin, Zhang; Wei, Li

2017-11-01

In view of the deficiency of the saturated silt clay foundation reinforced by the dynamic consolidation method, combination the project of soft foundation treatment test area in Tangshan, the reaserch analysed indexes, included groundwater level, pore water pressure, settlement about soil layer and so on, by use of field tests and indoor geotechnical tests, The results showed that the whole reinforcement effect with vacuum dynamic compaction method to blow fill foundation is obvious, due to the result of vacuum precipitation, generally, the excess pore water pressure can be dissipated by 90% above in 2 days around and the effective compaction coefficient can reached more than 0.9,the research work in soft foundation treatment engineering provide a new method and thought to similar engineering.

Long-term disturbance dynamics and resilience of tropical peat swamp forests

PubMed Central

Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

2015-01-01

1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c. 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c. 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c. 500 years ago, these communities started to decline. 5. Synthesis. Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude, causing the observed decline in the peat swamp forest communities in the last c. 500 years and challenging the ecosystem's persistence. This study greatly extends our knowledge of the ecological functioning of these understudied ecosystems, providing baseline information on the past vegetation and its response to disturbance. This understanding is central to developing management strategies that foster resilience in the remaining peat swamp forests and ensure continued provision of services, namely carbon storage, from this globally important ecosystem. PMID:26120202

Long-term disturbance dynamics and resilience of tropical peat swamp forests.

PubMed

Cole, Lydia E S; Bhagwat, Shonil A; Willis, Katherine J

2015-01-01

1. The coastal peat swamp forests of Sarawak, Malaysian Borneo, are undergoing rapid conversion, predominantly into oil palm plantations. This wetland ecosystem is assumed to have experienced insignificant disturbance in the past, persisting under a single ecologically-stable regime. However, there is limited knowledge of the past disturbance regime, long-term functioning and fundamentally the resilience of this ecosystem to changing natural and anthropogenic perturbations through time. 2. In this study, long-term ecological data sets from three degraded peatlands in Sarawak were collected to shed light on peat swamp forest dynamics. Fossil pollen and charcoal were counted in each sedimentary sequence to reconstruct vegetation and investigate responses to past environmental disturbance, both natural and anthropogenic. 3. Results demonstrate that peat swamp forest taxa have dominated these vegetation profiles throughout the last c . 2000-year period despite the presence of various drivers of disturbance. Evidence for episodes of climatic variability, predominantly linked to ENSO events, and wildfires is present throughout. However, in the last c . 500 years, burning and indicators of human disturbance have elevated beyond past levels at these sites, concurrent with a reduction in peat swamp forest pollen. 4. Two key insights have been gained through this palaeoecological analysis: (i) peat swamp forest vegetation has demonstrated resilience to disturbance caused by burning and climatic variability in Sarawak in the late Holocene, however (ii) coincident with increased fire combined with human impact c . 500 years ago, these communities started to decline. 5. Synthesis . Sarawak's coastal peat swamps have demonstrated resilience to past natural disturbances, with forest vegetation persisting through episodes of fire and climatic variability. However, palaeoecological data presented here suggest that recent, anthropogenic disturbances are of a greater magnitude, causing the observed decline in the peat swamp forest communities in the last c . 500 years and challenging the ecosystem's persistence. This study greatly extends our knowledge of the ecological functioning of these understudied ecosystems, providing baseline information on the past vegetation and its response to disturbance. This understanding is central to developing management strategies that foster resilience in the remaining peat swamp forests and ensure continued provision of services, namely carbon storage, from this globally important ecosystem.

Did We Really Land on the Moon? Suggestions for Science Teachers

NASA Technical Reports Server (NTRS)

Lowman, Paul D., Jr.; Smith, David E. (Technical Monitor)

2001-01-01

On Feb. 15, 2001, the FOX network broadcast a one hour TV program claiming that the Apollo lunar landings had all been staged in a studio set in Nevada, and that astronauts had never landed on the Moon. This claim can be refuted on many points, focused on the supposed photographic evidence indicating studio lighting or other aspects of the Apollo missions. The TV program ignored the returned lunar samples. Science teachers have been swamped with questions about the program, and this paper has been written to suggest how they can use it to stimulate interest in lunar geology. The article shows how the NASA Lunar Disk kits, available on loan to schools, can be studied by students. These samples are visibly different from terrestrial soils and rocks in several ways. There is no quartz in the lunar soil; there are no true reds and browns resulting from ferric oxides; and the textures of the soil (agglutinates and glass beads) can only be formed on an airless planet. The article has several pictures of the lunar surface and the Apollo samples, and a short bibliography for background reading.

Prediction of soft soil foundation settlement in Guangxi granite area based on fuzzy neural network model

NASA Astrophysics Data System (ADS)

Luo, Junhui; Wu, Chao; Liu, Xianlin; Mi, Decai; Zeng, Fuquan; Zeng, Yongjun

2018-01-01

At present, the prediction of soft foundation settlement mostly use the exponential curve and hyperbola deferred approximation method, and the correlation between the results is poor. However, the application of neural network in this area has some limitations, and none of the models used in the existing cases adopted the TS fuzzy neural network of which calculation combines the characteristics of fuzzy system and neural network to realize the mutual compatibility methods. At the same time, the developed and optimized calculation program is convenient for engineering designers. Taking the prediction and analysis of soft foundation settlement of gully soft soil in granite area of Guangxi Guihe road as an example, the fuzzy neural network model is established and verified to explore the applicability. The TS fuzzy neural network is used to construct the prediction model of settlement and deformation, and the corresponding time response function is established to calculate and analyze the settlement of soft foundation. The results show that the prediction of short-term settlement of the model is accurate and the final settlement prediction result has certain engineering reference value.

New Lepidocyrtus Bourlet, 1839 from riverine woodland in Hungary (Collembola, Entomobryidae).

PubMed

Winkler, Daniel

2017-04-10

Systematic soil fauna survey of riverine and swamp woodland habitats in West Hungary provided the opportunity to describe the new species L. isabelleae sp. nov. belonging to the the Lepidocyrtus pallidus-serbicus group. The new species is characterized by the dorsal macrochaetae formula R0R1sR1R2STSo/00/0101+2, the absence of scales on the antennae and legs beyond coxae and an additional dorsolateral macrochaeta (a7) on Abd. III. On this occasion, the L. pallidus-serbicus group has been revised and reinterpreted, and a differentiation key for the derived L. serbicus group has been developed.

AmeriFlux US-CRT Curtice Walter-Berger cropland

DOE Data Explorer

Chen, Jiquan [University of Toledo / Michigan State University

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site US-CRT Curtice Walter-Berger cropland. Site Description - The conventional cropland site is rain fed and no irrigation is applied. As it is located in a part of the historic Great Black Swamp, drainage tiles are deployed around 0.5–1.0 m beneath the ground surface in order to draw down the water level. The soil is classified as silty clay and silty clay loam. The cultivation practices include minimum tillage and both insect and weed control.  During the study period, the cropland was planted with soybean and winter wheat.

Application of satellite data and LARS's data processing techniques to mapping vegetation of the Dismal Swamp. M.S. Thesis - Old Dominion Univ.

NASA Technical Reports Server (NTRS)

Messmore, J. A.

1976-01-01

The feasibility of using digital satellite imagery and automatic data processing techniques as a means of mapping swamp forest vegetation was considered, using multispectral scanner data acquired by the LANDSAT-1 satellite. The site for this investigation was the Dismal Swamp, a 210,000 acre swamp forest located south of Suffolk, Va. on the Virginia-North Carolina border. Two basic classification strategies were employed. The initial classification utilized unsupervised techniques which produced a map of the swamp indicating the distribution of thirteen forest spectral classes. These classes were later combined into three informational categories: Atlantic white cedar (Chamaecyparis thyoides), Loblolly pine (Pinus taeda), and deciduous forest. The subsequent classification employed supervised techniques which mapped Atlantic white cedar, Loblolly pine, deciduous forest, water and agriculture within the study site. A classification accuracy of 82.5% was produced by unsupervised techniques compared with 89% accuracy using supervised techniques.

Identification of a testis-enriched heat shock protein and fourteen members of Hsp70 family in the swamp eel.

PubMed

He, Yan; Luo, Majing; Yi, Minhan; Sheng, Yue; Cheng, Yibin; Zhou, Rongjia; Cheng, Hanhua

2013-01-01

Gonad differentiation is one of the most important developmental events in vertebrates. Some heat shock proteins are associated with gonad development. Heat shock protein 70 (Hsp70) in the teleost fish and its roles in sex differentiation are poorly understood. We have identified a testis-enriched heat shock protein Hspa8b2 in the swamp eel using Western blot analysis and Mass Spectrometry (MS). Fourteen Hsp70 family genes were further identified in this species based on transcriptome information. The phylogenetic tree of Hsp70 family was constructed using the Maximum Likelihood method and their expression patterns in the swamp eel gonads were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). There are fourteen gene members in the Hsp70 family in the swamp eel genome. Hsp70 family, particularly Hspa8, has expanded in the species. One of the family members Hspa8b2 is predominantly expressed in testis of the swamp eel.

The effects of engineering fabric in street pavement on low bearing capacity soil in New Orleans : executive summary.

DOT National Transportation Integrated Search

1985-07-01

Subsurface soil in the New Orleans area is generally composed of peat and clay. The low bearing capacity of the soft natural soil has caused early deterioration of asphaltic concrete pavements which typically fail prior to carrying their designed loa...

Effects of the Suwannee River sill on the hydrology of the Okefenokee Swamp: application of research results in the environmental assessment process

Treesearch

Cynthia S. Loftin; Sara B. Aicher; Wiley M. Kitchens

2000-01-01

The Okefenokee Swamp is a 200,000 ha palustrine, freshwater wetland in the southeastern United States managed as a National Wildlife Refuge and a National Wilderness Area. Wildfires frequently occur, modifying vegetation structure and creating the swamp landscape mosaic. Following extensive wildfires in 1954-1955, the Suwannee River was impounded by a dam (Suwannee...

Geologic and geomorphic controls of coal development in some Tertiary Rocky Mountain basins, USA

USGS Publications Warehouse

Flores, R.M.

1993-01-01

Previous investigations have not well defined the controls on the development of minable coals in fluvial environments. This study was undertaken to provide a clearer understanding of these controls, particularly in of the lower Tertiary coal-bearing deposits of the Raton and Powder River basins in the Rocky Mountain region of the United States. In this region, large amounts of coals accumulated in swamps formed in the flow-through fluvial systems that infilled these intermontane basins. Extrabasinal and intrabasinal tectonism partly controlled the stratigraphic and facies distributions of minable coal deposits. The regional accumulation of coals was favored by the rapid basin subsidence coupled with minimal uplift of the source area. During these events, coals developed in swamps associated with anastomosed and meandering fluvial systems and alluvial fans. The extensive and high rate of sediment input from these fluvial systems promoted the formation of ombrotrophic, raised swamps, which produced low ash and anomalously thick coals. The petrology and palynology of these coals, and the paleobotany of the associated sediments, suggest that ombrotrophic, raised swamps were common in the Powder River Basin, where the climate during the early Tertiary was paratropical. The paleoecology of these swamps is identical to that of the modern ombrotrophic, raised swamps of the Baram and Mahakam Rivers of Borneo. ?? 1993.

The "soil" of Mars (viking 1).

PubMed

Shorthill, R W; Moore, H J; Scott, R F; Hutton, R E; Liebes, S; Spitzer, C R

1976-10-01

The location of the Viking 1 lander is most ideal for the study of soil properties because it has one footpad in soft material and one on hard material. As each soil sample was acquired, information on soil properties was obtained. Although analysis is still under way, early results on bulk density, particle size, angle of internal friction, cohesion, adhesion, and penetration resistance of the soil of Mars are presented.

The "Soil" of mars (viking 1)

USGS Publications Warehouse

Shorthill, R.W.; Moore, H.J.; Scott, R.F.; Hutton, R.E.; Liebes, S.; Spitzer, G.R.

1976-01-01

The location of the Viking 1 lander is most ideal for the study of soil properties because it has one footpad in soft material and one on hard material. As each soil sample was acquired, information on soil properties was obtained. Although analysis is still under way, early results on bulk density, particle size, angle of internal friction, cohesion, adhesion, and penetration resistance of the soil of Mars are presented.

Orion Landing Simulation Eight Soil Model Comparison

NASA Technical Reports Server (NTRS)

Mark, Stephen D.

2009-01-01

LS-DYNA finite element simulations of a rigid Orion Crew Module (CM) were used to investigate the CM impact behavior on eight different soil models. Ten different landing conditions, characterized by the combination of CM vertical and horizontal velocity, hang angle, and roll angle were simulated on the eight different soils. The CM center of gravity accelerations, pitch angle, kinetic energy, and soil contact forces were the outputs of interest. The simulation results are presented, with comparisons of the CM behavior on the different soils. The soils analyzed in this study can be roughly categorized as soft, medium, or hard, according to the CM accelerations that occur when landing on them. The soft group is comprised of the Carson Sink Wet soil and the Kennedy Space Center (KSC) Low Density Dry Sand. The medium group includes Carson Sink Dry, the KSC High Density In-Situ Moisture Sand and High Density Flooded Sand, and Cuddeback B. The hard soils are Cuddeback A and the Gantry Unwashed Sand. The softer soils were found to produce lower peak accelerations, have more stable pitch behavior, and to be less sensitive to the landing conditions. This investigation found that the Cuddeback A soil produced the highest peak accelerations and worst stability conditions, and that the best landing performance was achieved on the KSC Low Density Dry Sand.

[Litter production and breakdown in swamps dominated by palms (Arecaceae) in northeastern Costa Rica].

PubMed

Myers, Ronald L

2013-09-01

In Raffia (Raphia taedigera) palm-swamps, it is frequent to observe high mounds at the base of the palm clumps. These mounds are formed by the accumulation of litter and organic matter, or might result from upturned roots of wind-thrown trees. The mounds serve as anchorage site for the palms, and could be important for the establishment of woody tree species in the swamp. The formation of these mounds might be explained by the unequal accumulation of organic matter in the wetland, or by differences in decomposition rates between Raffia litter versus the litter produced in adjacent mixed forests. To distinguish between these hypotheses, I compared the spatial distribution of litter in a R. taedigera swamp with the litter distribution on an adjacent slope forest, where litter distribution is expected to be homogeneous. In addition, I compared decomposition rates of major components of fine litter in three different environments: two wetlands dominated by palms (R. taedigera and Manicaria saccifera) and a slope forest that experiences lower inundation effects. On the palm swamp, noticeable concentration of litter was observed near the bases of clumps of palm as opposed to the swamp floor. In the adjacent slope forest, the magnitude of the differences in the distribution of litter is small and there is no accumulation at the base of emergent trees. It was also found that litter production increases during heavy rains and storms that follow dry periods. The swamp environment, independent of the litter, showed significantly lower decomposition rates than the surrounding forest slope. Furthermore, R. taedigera litter decomposes as fast as the slope forest litter. Overall, these results suggest that resistance to decomposition is not a major factor in the formation of mounds at the bases of R. taedigera clumps. Instead, litter accumulation contributes to the formation of the mounds that rise above the surface of the swamp.

Reinforced-soil embankment on soft foundation.

DOT National Transportation Integrated Search

2001-01-01

A section of I-670 in Columbus, OH, constructed during 1997-1998, includes a 33 ft. (l0 m) high embankment over a deposit of very soft sludge. The design used geosynthetics for reinforcement of the embankment and wick drains to accelerate the consoli...

Mathematical solution of the stone column effect on the load bearing capacity and settlement using numerical analysis

NASA Astrophysics Data System (ADS)

Madun, A.; Meghzili, S. A.; Tajudin, SAA; Yusof, M. F.; Zainalabidin, M. H.; Al-Gheethi, A. A.; Dan, M. F. Md; Ismail, M. A. M.

2018-04-01

The most important application of various geotechnical construction techniques is for ground improvement. Many soil improvement project had been developed due to the ongoing increase in urban and industrial growth and the need for greater access to lands. Stone columns are one of the best effective and feasible techniques for soft clay soil improvement. Stone columns increase the bearing capacity and reduce the settlement of soil. Finite element analyses were performed using the program PLAXIS 2D. An elastic-perfectly plastic constitutive relation, based on the Mohr–Coulomb criterion, governs the soft clay and stone column behaviour. This paper presents on how the response surface methodology (RSM) software is used to optimize the effect of the diameters and lengths of column on the load bearing capacity and settlement of soft clay. Load tests through the numerical modelling using Plaxis 2D were carried out on the loading plate at 66 mm. Stone column load bearing capacity increases with the increasing diameter of the column and settlement decreases with the increasing length of the column. Results revealed that the bigger column diameter, the higher load bearing capacity of soil while the longer column length, the lower settlement of soil. However, the optimum design of stone column was varied with each factor (diameter and length) separately for improvement.

Lateral deflection contribution to settlement estimates.

DOT National Transportation Integrated Search

2014-06-01

The construction of tall embankments on soft soils requires staged construction, which leads to the : consolidation of foundation soils, an increase in their effective stress, reduction in void ratio, and gain in shear : strength. However, tall emban...

Study on friction coefficient of soft soil based on particle flow code

NASA Astrophysics Data System (ADS)

Lei, Xiaohong; Zhang, Zhongwei

2017-04-01

There has no uniform method for determining the micro parameters in particle flow code, and the corresponding formulas obtained by each scholar can only be applied to similar situations. In this paper, the relationship between the micro parameters friction coefficient and macro parameters friction angle is established by using the two axis servo compression as the calibration experiment, and the corresponding formula is fitted to solve the difficulties of determining the PFC micro parameters which provide a reference for determination of the micro parameters of soft soil.

Mangrove Swamps

EPA Pesticide Factsheets

Mangrove swamps are coastal wetlands found in tropical and subtropical regions. They are characterized by halophytic (salt loving) trees, shrubs and other plants growing in brackish to saline tidal waters.

Seasonal Habitat Distribution Of Swamp Rabbits, White-Tailed Deer, and Small Mammals in Old Growth and Managed Bottomland Hardwood Forests

Treesearch

Winston P. Smith; Patrick A. Zollner

2001-01-01

We studied swamp rabbits, white-tailed deer, and small mammals in an old-growth and adjacent second-growth and young-growth bottomland hardwood forest stands in southern Arkansas, August 1991 – February 1993. Based on average home range size and degree of overlap, minimum and maximum density estimates of swamp rabbits were 31 per km2 (no overlap)...

Automatic categorization of land-water cover types of the Green Swamp, Florida, using Skylab multispectral scanner (S-192) data

NASA Technical Reports Server (NTRS)

Coker, A. E.; Higer, A. L.; Rogers, R. H.; Shah, N. J.; Reed, L. E.; Walker, S.

1975-01-01

The techniques used and the results achieved in the successful application of Skylab Multispectral Scanner (EREP S-192) high-density digital tape data for the automatic categorizing and mapping of land-water cover types in the Green Swamp of Florida were summarized. Data was provided from Skylab pass number 10 on 13 June 1973. Significant results achieved included the automatic mapping of a nine-category and a three-category land-water cover map of the Green Swamp. The land-water cover map was used to make interpretations of a hydrologic condition in the Green Swamp. This type of use marks a significant breakthrough in the processing and utilization of EREP S-192 data.

Reinforced-soil embankment on soft foundation : executive summary.

DOT National Transportation Integrated Search

2000-01-01

A section of I-670 in Columbus, OH, constructed during 1997-1998, includes a 33 ft. (l0 m) high embankment over a deposit of very soft sludge. The design used geosynthetics for reinforcement of the embankment and wick drains to accelerate the consoli...

Improved correlation between Texas cone penetrometer blow count and undrained shear strength of soft clays.

DOT National Transportation Integrated Search

2009-01-01

The objective of this project was to develop an improved correlation between Texas Cone Penetrometer (TCP) : blow count and undrained shear strength for soft, clay soils in the upper approximately 30 feet of the ground. Subsurface : explorations were...

Application of Electrokinetic Stabilisation (EKS) Method for Soft Soil: A Review

NASA Astrophysics Data System (ADS)

Azhar, ATS; Azim, MAM; Syakeera, NN; Jefferson, IF; Rogers, CDF

2017-08-01

Soil properties such as low shear strength, excessive compression, collapsing behavior, high swell potential are some of the undesirable properties of soils in geotechnical engineering and those properties would cause severe distress to the structures. To solve these, an innovative stabilization of Electrokinetic (EKS) has been introduced. Electrokinetic is an applicable technique to transport charged particles and fluid in an electric potential. The EKS demonstrates changes in soil pH due to electrolysis reactions, water flow between the electrodes and migration of ions towards the cathode. This treatment has proven its efficiency in consolidating organic, peat and clayey silt as well as less expensive than other methods. Otherwise, this method also gives advantage by not disturbing site. The primary objective of this review is to discuss the application of electrokinetic and to investigate the current knowledge of electrokinetic in geotechnical application through a literature search and review, including consideration of certain aspects related to the soft soil application that may be relevant to the future study and at the same time addressing some key issues and their implications on soil behaviors.

Stabilization of soft clay subgrades in Virginia : phase I laboratory study.

DOT National Transportation Integrated Search

2005-01-01

Many pavement subgrades in Virginia consist of wet, highly plastic clay or other troublesome soils. Such soils can be treated with traditional lime and cement stabilization methods. Alternatives, including lignosulfonates and polymers, are available,...

Seasonal variability in methane and nitrous oxide fluxes from tropical peatlands in the western Amazon basin

NASA Astrophysics Data System (ADS)

Arn Teh, Yit; Murphy, Wayne A.; Berrio, Juan-Carlos; Boom, Arnoud; Page, Susan E.

2017-08-01

The Amazon plays a critical role in global atmospheric budgets of methane (CH4) and nitrous oxide (N2O). However, while we have a relatively good understanding of the continental-scale flux of these greenhouse gases (GHGs), one of the key gaps in knowledge is the specific contribution of peatland ecosystems to the regional budgets of these GHGs. Here we report CH4 and N2O fluxes from lowland tropical peatlands in the Pastaza-Marañón foreland basin (PMFB) in Peru, one of the largest peatland complexes in the Amazon basin. The goal of this research was to quantify the range and magnitude of CH4 and N2O fluxes from this region, assess seasonal trends in trace gas exchange, and determine the role of different environmental variables in driving GHG flux. Trace gas fluxes were determined from the most numerically dominant peatland vegetation types in the region: forested vegetation, forested (short pole) vegetation, Mauritia flexuosa-dominated palm swamp, and mixed palm swamp. Data were collected in both wet and dry seasons over the course of four field campaigns from 2012 to 2014. Diffusive CH4 emissions averaged 36.05 ± 3.09 mg CH4-C m-2 day-1 across the entire dataset, with diffusive CH4 flux varying significantly among vegetation types and between seasons. Net ebullition of CH4 averaged 973.3 ± 161.4 mg CH4-C m-2 day-1 and did not vary significantly among vegetation types or between seasons. Diffusive CH4 flux was greatest for mixed palm swamp (52.0 ± 16.0 mg CH4-C m-2 day-1), followed by M. flexuosa palm swamp (36.7 ± 3.9 mg CH4-C m-2 day-1), forested (short pole) vegetation (31.6 ± 6.6 mg CH4-C m-2 day-1), and forested vegetation (29.8 ± 10.0 mg CH4-C m-2 day-1). Diffusive CH4 flux also showed marked seasonality, with divergent seasonal patterns among ecosystems. Forested vegetation and mixed palm swamp showed significantly higher dry season (47.2 ± 5.4 mg CH4-C m-2 day-1 and 85.5 ± 26.4 mg CH4-C m-2 day-1, respectively) compared to wet season emissions (6.8 ± 1.0 mg CH4-C m-2 day-1 and 5.2 ± 2.7 mg CH4-C m-2 day-1, respectively). In contrast, forested (short pole) vegetation and M. flexuosa palm swamp showed the opposite trend, with dry season flux of 9.6 ± 2.6 and 25.5 ± 2.9 mg CH4-C m-2 day-1, respectively, versus wet season flux of 103.4 ± 13.6 and 53.4 ± 9.8 mg CH4-C m-2 day-1, respectively. These divergent seasonal trends may be linked to very high water tables (> 1 m) in forested vegetation and mixed palm swamp during the wet season, which may have constrained CH4 transport across the soil-atmosphere interface. Diffusive N2O flux was very low (0.70 ± 0.34 µg N2O-N m-2 day-1) and did not vary significantly among ecosystems or between seasons. We conclude that peatlands in the PMFB are large and regionally significant sources of atmospheric CH4 that need to be better accounted for in regional emissions inventories. In contrast, N2O flux was negligible, suggesting that this region does not make a significant contribution to regional atmospheric budgets of N2O. The divergent seasonal pattern in CH4 flux among vegetation types challenges our underlying assumptions of the controls on CH4 flux in tropical peatlands and emphasizes the need for more process-based measurements during periods of high water table.

Southern deepwater swamps

Treesearch

William H. Conner

1998-01-01

The authors define, classify, and analyze the economic significance of southern deepwater swamps. They discuss the physical environment, vegetational communities, animal communities, management issues, and research needs for this complex resource.

Development of low-ash, planar peat swamps in an alluvial-plain setting: The no. 5 Block beds (westphalian D) of southern West Virginia

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

Staub, J.R.; Richards, B.K.

1993-07-01

Coals from the No. 5 Block coal beds (Westphalian D) of the central Appalachian basin are noted for their blocky, dull character and their low ash and low sulfur content. The beds are multiple benched, with rock partings separating benches. Individual benches have limited lateral extent and, where thick, are dominated by bright, high-ash coal at the base and dull, low-ash coal in the upper parts. The duller coals contain more exinite-group and inertinite-group macerals than the brighter coals. These coal beds are encased in sandstone units dominated by fining-upward sequences. The overall depositional setting is an alluvial-plain environment withmore » northwest-flowing channels spaced approximately 20 km apart. The channels were flanked by clastic swamps about 7 km wide. Low-ash peat accumulated in areas of the flood plain most distant from the channels. These peat-accumulating swamps were about 8 km across. In a few instances low-frequency flood events introduced fine siliciclastic sediment into the peat swamps, depositing a thin layer of sediment on top of the peat. This sediment layer is thicker where the underlying coal is the thickest. These thick coal areas are topographically lower than surrounding coal areas. This relationship between coal thickness, parting thickness, and topography indicates that these peat swamps were planar at the time of deposition. Individual coal benches contain abundant preserved cellular tissue (telocollinite, semifusinite, and fusinite) at most locations, suggesting that robust vegetation was widespread in the swamps and that the morphology was planar. The high concentrations of exinite-group an inertinite-group macerals in the upper parts of benches resulted from selective decomposition and oxidation of the peat in subaerial and aquatic planar-swamp environments.« less

Holocene sedimentation at Corkscrew Swamp (Collier Co. ): A model for the origin and evolution of the present wetland-dominated regime of south Florida

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

Stone, P.A.; Duever, M.J.; Meeder, J.F.

1993-03-01

A two-layer peat-over-marl (calcitic mud) sequence characterizes Corkscrew Swamp, a swamp/marsh complex in northern Big Cypress Swamp. The marl began depositing about 10,600 BP and based upon the regional modern analog represents a marsh (grassy) environment of relatively short seasonal flooding, rather than a marl lake. The marsh succeeded formerly dry land of full-glacial times on a long-emerged marine-sand and limestone peninsula. About 5,700 BP peat deposition began by the development of longer-flooded wetland, either marsh or woody swamp vegetation. Both shifts (Pleistocene/Holocene and mid-Holocene) represent onsets of wetter conditions, either episodically or by slowly passing critical thresholds, under controlmore » of climate and sea level (hydrologic baselevel). With the rise in average water level at and following each shift, in part by feedback from sediment infilling of the shallow (ca. 2.5m) mineral-substrate basin, the wetland and its deposit expanded upslope, both vertically and outward. A younger basal-peat date (3,900 BP) occurs toward the periphery. Some local topographic alteration by peat fire about 500 BP persists and affects the modern swamp vegetation. A wide swamp-to-marsh shift in other parts may have a similar cause. The shorter record yet revealed for the northern Everglades shows the same two-stage sequence, similar timing in peatland development, wetland and sediment expansion, and long-term (but there different) influences of local peatland topographic alteration. Many wetland areas in South Florida data from a mid-Holocene shift (7,000--4,000 BP).« less

Landing Gear/Soil Interaction Development of Criteria for Aircraft Operation on Soil During Turning and Multipass Operations

DTIC Science & Technology

1975-10-01

AFFDL-TR-75-78 LANDING GEAR/ SOIL INTERACTION DEVELOPMENT OF CRITERIA FOR AIRCRAFT "OPERATION ON SOIL DURING TURNING #"q AND MULTIPASS OPERATIONS cc...braking. Limited start-up force data were examined to determine a preliminary estimate of start-up drag ratios. A soft tire/ soil computer program was...distance, landing rollout, turning perfor nance, and number of allowable passes for a particular vehicle and select soil . .. 4 UNCLASSIFIED -i SECURITY

Geotechnical centrifuge use at University of Cambridge Geotechnical Centre, August-September 1991

NASA Astrophysics Data System (ADS)

Gilbert, Paul A.

1992-01-01

A geotechnical centrifuge applies elevated acceleration to small-scale soil models to simulate body forces and stress levels characteristic of full-size soil structures. Since the constitutive behavior of soil is stress level development, the centrifuge offers considerable advantage in studying soil structures using models. Several experiments were observed and described in relative detail, including experiments in soil dynamics and liquefaction study, an experiment investigation leaning towers on soft foundations, and an experiment investigating migration of hot pollutants through soils.

Lower Mississippi River Environmental Program. Report 3. Bird and Mammal Use of Main Stem Levee Borrow Pits Along the Lower Mississippi River.

DTIC Science & Technology

1986-02-01

overcup oak, tupelo gum, Nuttall oak, American elm , slippery elm , i , hickories, persimmon, silver maple, deciduous holly, swamp privet, and rose mallows...cottonwood, green ash, sugarberry, box elder, deciduous holly, osage orange, swamp privet, hickories, overcup oak, water locust, honey locust, slippery elm ...wood, box elder, osage orange, hickories, honey locust, water locust, slippery elm , swamp privet, sugarberry, persimmon, and rose mallows. Where

Comparing Avocado, Swamp Bay, and Camphortree as Hosts of Raffaelea lauricola Using a Green Fluorescent Protein (GFP)-Labeled Strain of the Pathogen.

PubMed

Campbell, A S; Ploetz, R C; Rollins, J A

2017-01-01

Raffaelea lauricola, a fungal symbiont of the ambrosia beetle Xyleborus glabratus, causes laurel wilt in members of the Lauraceae plant family. North American species in the family, such as avocado (Persea americana) and swamp bay (P. palustris), are particularly susceptible to laurel wilt, whereas the Asian camphortree (Cinnamomum camphora) is relatively tolerant. To determine whether susceptibility is related to pathogen colonization, a green fluorescent protein-labeled strain of R. lauricola was generated and used to inoculate avocado, swamp bay, and camphortree. Trees were harvested 3, 10, and 30 days after inoculation (DAI), and disease severity was rated on a 1-to-10 scale. By 30 DAI, avocado and swamp bay developed significantly more severe disease than camphortree (mean severities of 6.8 and 5.5 versus 1.6, P < 0.003). The extent of xylem colonization was recorded as the percentage of lumena that were colonized by the pathogen. More xylem was colonized in avocado than camphortree (0.9% versus 0.1%, P < 0.03) but colonization in swamp bay (0.4%) did not differ significantly from either host. Although there were significant correlations between xylem colonization and laurel wilt severity in avocado (r = 0.74), swamp bay (r = 0.82), and camphortree (r = 0.87), even severely affected trees of all species were scarcely colonized by the pathogen.

Brief communication: Artificial cranial modification in Kow Swamp and Cohuna.

PubMed

Durband, Arthur C

2014-09-01

The crania from Kow Swamp and Cohuna have been important for a number of debates in Australian paleoanthropology. These crania typically have long, flat foreheads that many workers have cited as evidence of genetic continuity with archaic Indonesian populations, particularly the Ngandong sample. Other scientists have alleged that at least some of the crania from Kow Swamp and the Cohuna skull have been altered through artificial modification, and that the flat foreheads possessed by these individuals are not phylogenetically informative. In this study, several Kow Swamp crania and Cohuna are compared to known modified and unmodified comparative samples. Canonical variates analyses and Mahalanobis distances are generated, and random expectation statistics are used to calculate statistical significance for these tests. The results of this study agree with prior work indicating that a portion of this sample shows evidence for artificial modification of the cranial vault. Many Kow Swamp crania and Cohuna display shape similarities with a population of known modified individuals from New Britain. Kow Swamp 1, 5, and Cohuna show the strongest evidence for modification, but other individuals from this sample also show evidence of culturally manipulated changes in cranial shape. This project provides added support for the argument that at least some Pleistocene Australian groups were practicing artificial cranial modification, and suggests that caution should be used when including these individuals in phylogenetic studies. Copyright © 2014 Wiley Periodicals, Inc.

Genetic characteristic of swamp buffalo (Bubalus bubalis) from Pampangan, South Sumatra based on blood protein profile

NASA Astrophysics Data System (ADS)

Windusari, Yuanita; Hanum, Laila; Wahyudi, Rizki

2017-11-01

Swamp buffalo (Bubalus bubalis) is an endemic species and one of the genetic wealth of South Sumatra with a distribution area in the district of Pampangan (OganIlir and OganOganIlir). Suspected inbreeding causes decreased phenotypic properties. Inbreeding among various swamp buffalo is certainly not only lower the qualities but also genotypes and phenotypes. It is of interest to determine kinship variants swamp buffaloes from Pampangan through the analysis of a blood protein profile. Blood protein profile of four variants swamps buffalo was studied by using five electrophoresis system i.e. pre-albumin (Palb), albumin (Alb), ceruloplasmin (Cp), transferrin (Tf) and transferrin post (Ptf). In this paper, it is obtained that there was no significant differences among the four variants of the buffaloes were used as a sample. Prealbumin has two alleles (Palb1 and Palb2), albumin has three alleles (Alba, AlbB, AlbC), ceruloplasmin has one allele (BPA), post-transferrin has one allele (PTFA) with an allele frequency 1.0000 at any time transferrin has two alleles (TFA and TFB) with the allele frequency of 0.7500 and 1.0000. Characteristics prealbumin (Palb), albumin (Alb), ceruloplasmin (Cp), and post-transferrin (P-tf) is monomorphic, while transferrin is polymorphic average heterozygosity values all loci (H) 0.1286. Based on average heterozygosity, the swamp buffalo (Bubalusbubalis) from Pampangan has low genetic variation and closest genetic relationship.

Use of sediment amendments to rehabilitate sinking coastal swamp forests in Louisiana

USGS Publications Warehouse

Middleton, Beth A.; Jiang, Ming

2013-01-01

Coastal wetlands are losing elevation worldwide, so that techniques to increase elevation such as sediment amendment might benefit these wetlands. This study examined the potential of sediment amendment to raise elevation and support the production and regeneration of vegetation in coastal forests in Louisiana. Before sediment amendment, the vegetation did not differ in these Taxodium distichum–Nyssa aquatica forests with respect to herbaceous and tree seedling composition, and sapling and tree characteristics. After the application of sediment in January 2007, sediment-amended swamps had higher elevations and salinity levels than natural swamps. The layer of sediment applied to Treasure Island in Jean Lafitte National Historic Park and Preserve was relatively deep (sediment depth at Site One and Site Two: 0.89 and 0.69 m, respectively, six months after application), and may have exceeded an optimal threshold. Sediment-amended swamp with the highest elevation had some tree mortality and little tree growth of T. distichum. Also, sediment-amended swamp had higher root biomasses of ruderal species, and lower species richness and cover of herbaceous species. Nevertheless, during controlled water releases during an oil spill emergency in 2010, both sediment-amended and reference forest had higher production levels than in other years. While sediment amendment is a compelling management alternative for sinking coastal wetlands, optimal thresholds were not determined for these T. distichum–N. aquatica swamps.

Goodbye, Viola Swamp!

ERIC Educational Resources Information Center

Bremer, Hale W.; Kuehmichel, Barbara

1979-01-01

A kindergarten teacher stimulated many language experience and dramatic activities when she came to class one day impersonating the crabby teacher Viola Swamp, from the children's story, "Miss Nelson Is Missing!" (SJL)

Testate amoebae analysis in the peat deposits of the swamp Dolgon’koye in the south of Western Siberia and peatland paleohydrology for last 3100 years

NASA Astrophysics Data System (ADS)

Kurina, Irina V.; Blyakharchuk, Tatiana A.

2018-03-01

Our research is devoted to paleohydrological reconstruction in the swamp located in the river valley on the piedmont of the Altai Mountains in the south of Western Siberia. The reconstruction was carried out based on rhizopod analysis for the last 3100 cal yr. A large amount of different testate amoebae was found in the peat. Total 64 testate amoebae taxa were recorded in the peat core with the most abundant being: Trinema lineare, Centropyxis aculeata, C. aerophila, Euglypha rotunda, Cryptodifflugia sp. Decrease of surface wetness in the swamp are observed 2280, 2140, 1900–600 cal yr BP and increase – in 2700, 2500–1900, 230–215 cal yr BP. The results of our reconstruction of the swamp paleohydrology agrees well with the paleoclimatic data obtained earlier for the central area of the south of Western Siberia Plain. It indicates a high sensitivity of the swamp to climatic changes in the Holocene. The rhizopod analysis proved to be very effective when used for paleohydrology reconstruction in minerotrophic peat.

The distribution of ichthyoplankton in thermal and non-thermal creeks and swamps on the Savannah River Plant, February-July 1985

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

Paller, M.H.; Saul, B.M.; Hughes, D.W.

1986-01-01

The report deals with the distribution of ichthyoplankton in the Savannah River tributary streams and associated swamps located on the SRP during the 1985 spawning season (February-July). The 1985 sampling program was a continuation of the 1984 program and, except for the addition of seven sampling stations and minor methodological changes, incorporated the same sampling sites and procedures. The streams under study were Upper Three Runs Creek, Beaver Dam Creek, Four Mile Creek, Pen Branch, Steel Creek, Meyer's Branch and Lower Three Runs Creek. The objectives were to determine: (1) the density, distribution and species composition of ichthyoplankton at samplemore » sites in the creeks and swamps of the SRP; (2) how ichthyoplankton in SRP creeks and swamps is distributed in relation to habitat and temperature; (3) the effects of elevated temperatures on ichthyoplankton distribution and abundance and on the time of spawning; and (4) the magnitude of yearly variations in ichthyoplankton abundance in the creeks and swamps of the SRP and the reasons for these variations.« less

Morphology and systematics of cordaites of Pennsylvanian coal swamps of Euramerica

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

Costanza, S.H.

1984-01-01

Cordaites are extinct coniferophytic shrubs and trees of the Late Paleozoic. They were most prominent in tropical coal swamps existing from the Westphalian A-B boundary of Western Europe to the middle Desmoinesian (Westphalian D) of midcontinental United States. Structurally preserved coal-ball cordaites from Pennsylvanian Euramerican coals were analyzed for whole plant understanding, morphological variation, and indications of ecological tolerances. Organ assemblages for individual species were established from coals where coal balls contain single cordaitean seed species. Cordaitean organ assemblages were stratigraphically compiled, compared, and cross-correlated. Cordaitean assemblage comparisons of most known coals with coal balls confirm organ assemblages established formore » Pennsylvanioxylon, and indicate that Mesoxylon bore Mitrospermum ovules. Mesoxylon and Pennsylvanioxylon are the only coal-swamp Pennsylvanian cordaitean genera recognized herein. They are consistently different in stem xylem development, leaf and branch trace formation, in amount of cortical sclerenchyma and associated organs. Morphology of coal-swamp cordaites, especially cortical aerenchyma in Pennsylvanioxylon, indicates semi-aquatic ecological adaptation. Coal-swamp cordaitean lineages may demonstrate both gradualistic and punctuational evolutionary changes.« less

Preliminary Facies Reconstruction of a Late Pleistocene Cypress Forest Discovered on the Northern Gulf of Mexico Continental Shelf

NASA Astrophysics Data System (ADS)

Gonzalez Rodriguez, S. M.; Bentley, S. J.; DeLong, K. L.; Xu, K.; Caporaso, A.; Obelcz, J. B.; Harley, G. L.; Reese, C. A.; Truong, J. T.

2016-12-01

We are investigating the origin and preservation of an ancient bald cypress forest (Taxodium distichum) discovered on the continental shelf seafloor, offshore of Gulf Shores, Alabama, USA, in 20 m water depth. The forest was likely buried in the late Pleistocene, possibly exhumed by Hurricane Ivan in 2004, and is now exposed as stumps in life position with little evidence of decay before recent marine exposure. Radiocarbon analyses show that the forest age is near (and in some cases beyond) the limits of 14C dating, at least 41-45 ky BP. In August 2015 and July 2016, submersible vibracores (up to 5 m in length) were collected. Ongoing core analyses include: organic content (loss on ignition), granulometry, and core logging using a Geotek Multi Sensor Core Logger to generate imagery, bulk density, and x-ray fluorescence data. To bolster 14C analyses, cores collected in 2016 are presently being dated using optically stimulated luminescence. Local stratigraphy consists of a surface facies of Holocene transgressive sands, underlain by possible estuarine sediments of interbedded sand and mud (potentially Holocene or Pleistocene), overlying a swamp or delta plain facies (likely Pleistocene) containing woody debris and mud. Deeper woody facies are thought to include the soil horizons of the ancient cypress forest. Cores collected in 2016 revealed a Pleistocene paleosol beneath Holocene sands in a nearby trough. Elevation differences between swamp and paleosol horizons will be evaluated from bathymetric and subbottom data, to help characterize the preserved ancient landscape. Initial interpretation based on close proximity of Pleistocene swamp and oxidized paleosol sediments, and regional geomorphic gradients suggest that this relatively diverse assemblage of facies developed up to tens of km from the glacial-age coastline, and relatively rapid burial prevented erosion by coastal processes during the Holocene transgression thus preserving the tree stumps and wood debris.

Emission Factors for CO2, CO, CH4, and C2 - C4 Hydrocarbons from the 2011 Great Dismal Swamp, Virginia Fire

NASA Astrophysics Data System (ADS)

Baker, S.; Soja, A. J.; Richardson, M. J.

2012-12-01

With a warming climate, increased dry conditions and drought periods are likely to result in higher fire activity in the wetlands of the eastern and southeastern US. Fires in this fuel type can smolder for months producing significant carbon release and major impacts on air quality. While a comprehensive set of emission factors has been established for most US fuel types, a less complete set is available for emissions where deep layers of organic matter can consume and smolder for days, weeks and months. Lightning started the Lateral West fire in the Great Dismal Swamp National Wildlife Refuge, Virginia on August 4, and it burned slowly through drought-stressed hardwood forest and dry peat soil. The fire produced dense plumes of smoke that mostly dispersed over the Atlantic Ocean, but also affected air quality as far away as Washington, D.C. Fire emissions were sampled August 26, 2011. The fire had burned 6,358 acres. and was smoldering along in the peat, with some brush still igniting. The average emission factors (EF) we measured from the sampling were 1441 g/kg CO2, 192 g/kg CO; and 16.5 g/kg CH4.. Modified combustion efficiency (MCE) was 0.83, produced by the small amount of flaming combustion mixed with smoldering combustion of the peat. The CO2 EF values are similar to those measured from smoldering duff in Alaska in 2003 (1436 g/kg), and the CO EF was lower than Alaska (244 g/kg CO), while the CH4 EF was much higher than Alaska (8.4 g/kg CH4). We will present our complete set of emission factors from the Great Dismal Swamp for CO2, CO, CH4, and C2 - C4 hydrocarbons, and contrast these results with other fuel types. Linear regressions of C1- C4 hydrocarbons vs. CO concentration will presented and compared with other emissions results.

Population density of red langurs in Sabangau tropical peat-swamp forest, Central Kalimantan, Indonesia.

PubMed

Ehlers Smith, David A; Ehlers Smith, Yvette C

2013-08-01

Because of the large-scale destruction of Borneo's rainforests on mineral soils, tropical peat-swamp forests (TPSFs) are increasingly essential for conserving remnant biodiversity, particularly in the lowlands where the majority of habitat conversion has occurred. Consequently, effective strategies for biodiversity conservation are required, which rely on accurate population density and distribution estimates as a baseline. We sought to establish the first population density estimates of the endemic red langur (Presbytis rubicunda) in Sabangau TPSF, the largest remaining contiguous lowland forest-block on Borneo. Using Distance sampling principles, we conducted line transect surveys in two of Sabangau's three principle habitat sub-classes and calculated group density at 2.52 groups km⁻² (95% CI 1.56-4.08) in the mixed-swamp forest sub-class. Based on an average recorded group size of 6.95 individuals, population density was 17.51 ind km⁻², the second highest density recorded in this species. The accessible area of the tall-interior forest, however, was too disturbed to yield density estimates representative of the entire sub-class, and P. rubicunda was absent from the low-pole forest, likely as a result of the low availability of the species' preferred foods. This absence in 30% of Sabangau's total area indicates the importance of in situ population surveys at the habitat-specific level for accurately informing conservation strategies. We highlight the conservation value of TPSFs for P. rubicunda given the high population density and large areas remaining, and recommend 1) quantifying the response of P. rubicunda to the logging and burning of its habitats; 2) surveying degraded TPSFs for viable populations, and 3) effectively delineating TPSF sub-class boundaries from remote imagery to facilitate population estimates across the wider peat landscape, given the stark contrast in densities found across the habitat sub-classes of Sabangau. © 2013 Wiley Periodicals, Inc.

Impacts of Projected Climate Warming and Wetting on Soil Microbial Communities in Alpine Grassland Ecosystems of the Tibetan Plateau.

PubMed

Zeng, Jun; Shen, Ju-Pei; Wang, Jun-Tao; Hu, Hang-Wei; Zhang, Cui-Jing; Bai, Ren; Zhang, Li-Mei; He, Ji-Zheng

2018-05-01

Climate change is projected to have impacts on precipitation and temperature regimes in drylands of high elevation regions, with especially large effects in the Qinghai-Tibetan Plateau. However, there was limited information about how the projected climate change will impact on the soil microbial community and their activity in the region. Here, we present results from a study conducted across 72 soil samples from 24 different sites along a temperature and precipitation gradient (substituted by aridity index ranging from 0.079 to 0.89) of the Plateau, to assess how changes in aridity affect the abundance, community composition, and diversity of bacteria, ammonia-oxidizers, and denitrifers (nirK/S and nosZ genes-containing communities) as well as nitrogen (N) turnover enzyme activities. We found V-shaped or inverted V-shaped relationships between the aridity index (AI) and soil microbial parameters (gene abundance, community structures, microbial diversity, and N turnover enzyme activities) with a threshold at AI = 0.27. The increasing or decreasing rates of the microbial parameters were higher in areas with AI < 0.27 (alpine steppes) than in mesic areas with 0.27 < AI < 0.89 (alpine meadow and swamp meadow). The results indicated that the projected warming and wetting have a strong impact on soil microbial communities in the alpine steppes.

Selective Leaching of Dissolved Organic Matter From Alpine Permafrost Soils on the Qinghai-Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wang, Yinghui; Xu, Yunping; Spencer, Robert G. M.; Zito, Phoebe; Kellerman, Anne; Podgorski, David; Xiao, Wenjie; Wei, Dandan; Rashid, Harunur; Yang, Yuanhe

2018-03-01

Ongoing global temperature rise has caused significant thaw and degradation of permafrost soils on the Qinghai-Tibetan Plateau (QTP). Leaching of organic matter from permafrost soils to aquatic systems is highly complex and difficult to reproduce in a laboratory setting. We collected samples from natural seeps of active and permafrost layers in an alpine swamp meadow on the QTP to shed light on the composition of mobilized dissolved organic matter (DOM) by combining optical measurements, ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry, radiocarbon (14C), and solid-state 13C nuclear magnetic resonance spectroscopy. Our results show that even though the active layer soils contain large amounts of proteins and carbohydrates, there is a selective release of aromatic components, whereas in the deep permafrost layer, carbohydrate and protein components are preferentially leached during the thawing process. Given these different chemical characteristics of mobilized DOM, we hypothesize that photomineralization contributes significantly to the loss of DOM that is leached from the seasonally thawed surface layer. However, with continued warming, biodegradation will become more important since biolabile materials such as protein and carbohydrate are preferentially released from deep-layer permafrost soils. This transition in DOM leachate source and associated chemical composition has ramifications for downstream fluvial networks on the QTP particularly in terms of processing of carbon and associated fluxes.

Refining soil organic carbon stock estimates for China’s palustrine wetlands

NASA Astrophysics Data System (ADS)

Ma, Kun; Liu, Junguo; Zhang, Ying; Parry, Lauren E.; Holden, Joseph; Ciais, Philippe

2015-12-01

Palustrine wetlands (PWs) include all bogs, fens, swamps and marshes that are non-saline and which are not lakes or rivers. They therefore form a highly important group of wetlands which hold large carbon stocks. If these wetlands are not protected properly they could become a net carbon source in the future. Compilation of spatially explicit wetland databases, national inventory data and in situ measurement of soil organic carbon (SOC) could be useful to better quantify SOC and formulate long-term strategies for mitigating global climate change. In this study, a synergistic mapping approach was used to create a hybrid map for PWs for China and to estimate their SOC content. Total SOC storage in PWs was estimated to be 4.3 ± 1.4 Pg C, with a SOC density of 31.17 (±10.55) kg C m-2 in the upper 1 m of the soil layer. This carbon stock is concentrated in Northeast China (49%) and the Qinghai-Tibet Plateau (41%). Given the large pool of carbon stored in PWs compared to other soil types, we suggest that urgent monitoring programmes on SOC should be established in regions with very few datasets, but where PWs appear to be common such as the Tibet region and Northwest China.

Prediction of Vehicle Mobility on Large-Scale Soft-Soil Terrain Maps Using Physics-Based Simulation

DTIC Science & Technology

2016-08-04

soil type. The modeling approach is based on (i) a seamless integration of multibody dynamics and discrete element method (DEM) solvers, and (ii...ensure that the vehicle follows a desired path. The soil is modeled as a Discrete Element Model (DEM) with a general cohesive material model that is

Responses of Soil Microbial Communities to Experimental Warming in Alpine Grasslands on the Qinghai-Tibet Plateau

PubMed Central

He, Xingyuan; Liu, Wenjie; Zhao, Qian; Zhao, Lin; Tian, Chunjie

2014-01-01

Global surface temperature is predicted to increase by at least 1.5°C by the end of this century. However, the response of soil microbial communities to global warming is still poorly understood, especially in high-elevation grasslands. We therefore conducted an experiment on three types of alpine grasslands on the Qinghai-Tibet Plateau to study the effect of experimental warming on abundance and composition of soil microbial communities at 0–10 and 10–20 cm depths. Plots were passively warmed for 3 years using open-top chambers and compared to adjacent control plots at ambient temperature. Soil microbial communities were assessed using phospholipid fatty acid (PLFA) analysis. We found that 3 years of experimental warming consistently and significantly increased microbial biomass at the 0–10 cm soil depth of alpine swamp meadow (ASM) and alpine steppe (AS) grasslands, and at both the 0–10 and 10–20 cm soil depths of alpine meadow (AM) grasslands, due primarily to the changes in soil temperature, moisture, and plant coverage. Soil microbial community composition was also significantly affected by warming at the 0–10 cm soil depth of ASM and AM and at the 10–20 cm soil depth of AM. Warming significantly decreased the ratio of fungi to bacteria and thus induced a community shift towards bacteria at the 0–10 cm soil depth of ASM and AM. While the ratio of arbuscular mycorrhizal fungi to saprotrophic fungi (AMF/SF) was significantly decreased by warming at the 0–10 cm soil depth of ASM, it was increased at the 0–10 cm soil depth of AM. These results indicate that warming had a strong influence on soil microbial communities in the studied high-elevation grasslands and that the effect was dependent on grassland type. PMID:25083904

Integral abutment bridge for Louisiana's soft and stiff soils : tech summary.

DOT National Transportation Integrated Search

2016-03-01

In this project, fi eld-instrumentation, monitoring, and analyzing the design and : construction of full integral abutment bridges for Louisianas fi ne sand and silty sand : deposit and clay soil conditions were conducted. Comparison of results wa...

Integral abutment bridge for Louisiana's soft and stiff soils : Tech summary.

DOT National Transportation Integrated Search

2016-03-01

In this project, fi eld-instrumentation, monitoring, and analyzing the design and : construction of full integral abutment bridges for Louisianas fi ne sand and silty sand : deposit and clay soil conditions were conducted. Comparison of results wa...

I-15 reconstruction long-term embankment monitoring study : final report.

DOT National Transportation Integrated Search

2012-05-01

The I-15 Reconstruction Project in Salt Lake City, Utah required rapid embankment construction in an urban environment atop soft lacustrine soils. These soils are thick, highly compressible, have low shear strength and require significant time to com...

Estimation of soft sediment thickness in Kuala Lumpur based on microtremor observation data

NASA Astrophysics Data System (ADS)

Chiew, Chang Chyau; Cheah, Yi Ben; Tan, Chin Guan; Lau, Tze Liang

2017-10-01

Seismic site effect is one of the major concerns in earthquake engineering. Soft ground tends to amplify the seismic wave in surficial geological layers. The determination of soft ground thickness on the surface layers of the earth is an important input for seismic hazard assessment. This paper presents an easy and convenient approach to estimate the soft sediment thickness at the site using microtremor observation technique. A total number of 133 survey points were conducted in selected sites around Kuala Lumpur area using a microtremor measuring instrument, but only 103 survey points contributed to the seismic microzonation and sediment thickness plots. The bedrock of Kuala Lumpur area is formed by Kenny Hill Formation, limestone, granite, and the Hawthornden Schist; however, the thickness of surface soft ground formed by alluvial deposits, mine tailings, and residual soils remains unknown. Hence, the predominant frequency of the ground in each site was determined based on Nakamura method. A total number of 14 sites with known depth to bedrock from the supply of geotechnical reports in the study area were determined. An empirical correlation was developed to relate the ground predominant frequency and soft ground thickness. This correlation may contribute to local soil underlying the subsurface of Kuala Lumpur area. The finding provides an important relationship for engineers to estimate the soft ground thickness in Kuala Lumpur area based on the dynamic characteristics of the ground measured from microtremor observation.

Okefenokee Swamp Fire, Georgia

NASA Image and Video Library

2002-05-22

Large smoke plumes were produced by the Blackjack complex fire in southeastern Georgia Okefenokee Swamp as seen by the MISR instrument aboard NASA Terra spacecraft May 8, 2002. 3D glasses are necessary to view this image.

The Warm-Blooded Plant of the Swamps.

ERIC Educational Resources Information Center

Camazine, Scott

1986-01-01

Describes remarkable characteristics of the skunk cabbage (Symplocarpus foetidus) which make it an interesting swamp plant to study in February and March: its warm-blooded nature, unpleasant skunky odor, and peculiar root system. (NEC)

Wetland Silvicultural Systems

Treesearch

Robert L. Johnson

1981-01-01

Many forests of the lowlands and swamps of the Midsouth are occasionally to frequently inundated. Such forests are common along the Mississippi, White, Red, Mobile, Tombigbee, and Alabama Rivers, and in coastal swamps such as the Atchafalaya Basin.

Mixing, trapping and outwelling in the Klong Ngao mangrove swamp, Thailand

NASA Astrophysics Data System (ADS)

Wattayakorn, Gullaya; Wolanski, Eric; Kjerfve, Björn

1990-11-01

The Klong Ngao estuary in Thailand is a 7·5-km long tidal creek facing the Andaman Sea and drains 11·5 km 2 of mangrove swamps. Physical processes in the estuary differ greatly from the wet season to the dry season. In the dry season, vertical homogeneity prevails and the swamp behaves like an evaporation pond. Salt and water are trapped upstream, longitudinal gradients result and, through tidal dispersion, nutrient outwelling may result for SiO 2, possibly NO 2 and NO 3, but not PO 4. The outflow is trapped in a coastal boundary layer. In the wet season, short-lived local floods generate a strong stratification in salinity and episodical flushing of the estuary and may make measurements of nutrient budgets inconclusive. The Klong Ngao mangrove swamp traps land-derived sediments in the wet season.

Environmental processes and spectral reflectance characteristics associated with soil erosion in desert fringe regions

NASA Technical Reports Server (NTRS)

Jacobberger, P. A.

1986-01-01

Two Thematic Mapper (TM) scenes were acquired. A scene was acquired for the Bahariya, Egypt field area, and one was acquired covering the Okavango Delta site. Investigations at the northwest Botswana study sites have concentrated upon a system of large linear (alab) dunes possessing an average wavelength of 2 kilometers and an east-west orientation. These dunes exist to the north and west of the Okavango Swamp, the pseudodeltaic end-sink of the internal Okavango-Cubango-Cuito drainage network. One archival scene and two TM acquisitions are on order, but at present no TM data were acquired for the Tombouctou/Azaouad Dunes, Mali. The three areas taken together comprise an environmental series ranging from hyperarid to semi-arid, with desertization processes operational or incipient in each. The long range goal is to predict normal seasonal variations, so that aperiodic spectral changes resulting from soil erosion, vegetation damage, and associated surface processes would be distinguishable as departures from the norm.

Hybridization and extinction.

PubMed

Todesco, Marco; Pascual, Mariana A; Owens, Gregory L; Ostevik, Katherine L; Moyers, Brook T; Hübner, Sariel; Heredia, Sylvia M; Hahn, Min A; Caseys, Celine; Bock, Dan G; Rieseberg, Loren H

2016-08-01

Hybridization may drive rare taxa to extinction through genetic swamping, where the rare form is replaced by hybrids, or by demographic swamping, where population growth rates are reduced due to the wasteful production of maladaptive hybrids. Conversely, hybridization may rescue the viability of small, inbred populations. Understanding the factors that contribute to destructive versus constructive outcomes of hybridization is key to managing conservation concerns. Here, we survey the literature for studies of hybridization and extinction to identify the ecological, evolutionary, and genetic factors that critically affect extinction risk through hybridization. We find that while extinction risk is highly situation dependent, genetic swamping is much more frequent than demographic swamping. In addition, human involvement is associated with increased risk and high reproductive isolation with reduced risk. Although climate change is predicted to increase the risk of hybridization-induced extinction, we find little empirical support for this prediction. Similarly, theoretical and experimental studies imply that genetic rescue through hybridization may be equally or more probable than demographic swamping, but our literature survey failed to support this claim. We conclude that halting the introduction of hybridization-prone exotics and restoring mature and diverse habitats that are resistant to hybrid establishment should be management priorities.

Biology and control of swamp dodder (Cuscuta gronovii)

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

Bewick, T.A.

1987-01-01

A simple model predicting swamp dodder (Cuscuta gronovii Willd.) emergence was developed. The model states that 0.1% of the cranberry seedlings will emerge after 150 to 170 GDD have accumulated after the winter ice has melted on the cranberry beds, using 0 C as the low temperature threshold. Experiments in cranberry showed that pronamide (3,5-dichloro-(N-1,1-dimethyl-2-propynyl)benzamide) was effective in controlling swamp dodder when applied preemergence. Rates below 2.4 kg ai/ha appeared to be safe for cranberry plants and fruit. Experiments with /sup 14/C glyphosate showed that the herbicide moved out of carrot leaves to the physiological sinks in the plant. Inmore » carrots parasitized by swamp dodder the dodder acted as one of the strongest sinks for photosynthates from the host. In cranberry glyphosate moved out of the leaves, but most remained in the stem to which the treated leaves were attached. The only physiological sinks that accumulated significant amounts of label were the stem apices. The concentration of the herbicide in this sink decreased with time. Swamp dodder stems were able to absorb glyphosate directly from solution.« less

The Productivity and Natural Increase of Swamp Buffalo in District Malang

NASA Astrophysics Data System (ADS)

Budiarto, A.; Ciptadi, G.

2018-02-01

The purpose of this research was to collect the basic information needed to develop a sustainable breeding program, which includes the potential for production and reproduction of buffaloes. This research was conducted on swamp buffalo in Malang Regency East Java. The research method used was survey method. Primary data was obtained from direct observation on 323 tails owned by 98 breeders. Variables observed were population growth and reproductive performance. The data obtained were analyzed descriptively. The result showed that the initial population study of swamp Buffaloes in Malang as many as 1155 with male and female ratio 1: 2. The ratios of male and female swamp Buffalo 20 percent male and 80 percent female. Overall, the buffalo reproduction performance was still low. Service per conception 2.06 ± 0.88; Anestrus Postpartum 7.46 ± 3.83 months; calving interval distance 17.82 ± 4.86 months; 20.43 % birth rate and 4.33% mortality rate of Natural Increase (NI) population was about 16,1%. In conclusion, the value of NI of swamp Buffalo in Malang Regency is still low. To increase buffalo productivity, buffalo breeding program is continuously based on reproduction control.

Distribution of periphytic algae in wetlands (Palm swamps, Cerrado), Brazil.

PubMed

Dunck, B; Nogueira, I S; Felisberto, S A

2013-05-01

The distribution of periphytic algae communities depends on various factors such as type of substrate, level of disturbance, nutrient availability and light. According to the prediction that impacts of anthropogenic activity provide changes in environmental characteristics, making impacted Palm swamps related to environmental changes such as deforestation and higher loads of nutrients via allochthonous, the hypothesis tested was: impacted Palm swamps have higher richness, density, biomass and biovolume of epiphytic algae. We evaluated the distribution and structure of epiphytic algae communities in 23 Palm swamps of Goiás State under different environmental impacts. The community structure attributes here analyzed were composition, richness, density, biomass and biovolume. This study revealed the importance of the environment on the distribution and structuration of algal communities, relating the higher values of richness, biomass and biovolume with impacted environments. Acidic waters and high concentration of silica were important factors in this study. Altogether 200 taxa were identified, and the zygnemaphycea was the group most representative in richness and biovolume, whereas the diatoms, in density of studied epiphyton. Impacted Palm swamps in agricultural area presented two indicator species, Gomphonema lagenula Kützing and Oedogonium sp, both related to mesotrophic to eutrophic conditions for total nitrogen concentrations of these environments.

The temperature characteristics of biological active period of the peat soils of Bakchar swamp

NASA Astrophysics Data System (ADS)

Kiselev, M. V.; Dyukarev, E. A.; Voropay, N. N.

2018-01-01

The results of the study of the peculiarities of the temperature regime in the five basic ecosystems of oligotrophic bogs in the south taiga zone of Western Siberia in 2011-2016 are presented. The soil temperature regime was studied using the atmospheric-soil measuring complex at different depths from surface to 240 cm. All sites were divided into two groups according the bog water level: flooded sites (hollow and open fen) and drained sites (ridge, tall and low ryam). Waterlogged sites are better warmed in the summer period, and slowly freeze in the winter period. The analysis of the annual cycle of temperature showed that the maximum surface temperature is observed in July. The minimum temperature on the surface observed in February or January. The greatest temperature gradient was recorded in the upper 2 cm layer. The gradient at the open fen was -2 °C·cm-1 in February and 1.1 °C·cm-1 in October. The peak of formation of the seasonally frozen layer occurs at the end of autumn, beginning of winter. The degradation of the seasonally frozen layer was observed both from top and bottom, but degradation from the top is faster.

Georgia: Okefenokee Swamp

Atmospheric Science Data Center

2014-05-15

... the swamp ecosystem, however, and a number of key plant and animal species within the Okefenokee National Wildlife Refuge ecosystems are ... NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Science Mission Directorate, Washington, D.C. The Terra spacecraft is managed ...

Soil and periphyton indicators of anthropogenic water-quality changes in a rainfall-driven wetland

USGS Publications Warehouse

McCormick, P.V.

2011-01-01

Surface soils and periphyton communities were sampled across an oligotrophic, soft-water wetland to document changes associated with pulsed inputs of nutrient- and mineral-rich canal drainage waters. A gradient of canal-water influence was indicated by the surface-water specific conductance, which ranged between 743 and 963 ??S cm-1 in the canals to as low as 60 ??S cm-1 in the rainfall-driven wetland interior. Changes in soil chemistry and periphyton taxonomic composition across this gradient were described using piecewise regressions models. The greatest increase in soil phosphorus (P) concentration occurred at sites closest to the canal while soil mineral (sulfur, calcium) concentrations increased most rapidly at the lower end of the gradient. Multiple periphyton shifts occurred at the lower end of the gradient and included; (1) a decline in desmids and non-desmid filamentous chlorophytes, and their replacement by a diatom-dominated community; (2) the loss of soft-water diatom indicator species and their replacement by hard-water species. Increased dominance by cyanobacteria and eutrophic diatom indicators occurred closer to the canals. Soil and periphyton changes indicated four zones of increasing canal influence across the wetland: (1) a zone of increasing mineral concentrations where soft-water taxa remained dominant; (2) a transition towards hard-water, oligotrophic diatoms as mineral concentrations increased further; (3) a zone of dominance by these hard-water species; (4) a zone of rapidly increasing P concentrations and dominance by eutrophic taxa. In contrast to conclusions drawn from routine water-chemistry monitoring, measures of chemical and biological change presented here indicate that most of this rainfall-driven peatland receives some influence from canal discharges. These changes are multifaceted and induced by shifts in multiple chemical constituents. ?? 2010 US Government.

Determining resistance to soft-rot fungi

Treesearch

C. G. Duncan

1965-01-01

A laboratory procedure is outlined that incorporates techniques found to promote soft rot by several fungi. This procedure employs either an agar or a soil substrate. Also presented are the principal findings of experiments underlying the procedure. Results of tests conducted according to the suggested procedure are illustrated. The overall decay resistance of the...

Modification of Hazen's equation in coarse grained soils by soft computing techniques

NASA Astrophysics Data System (ADS)

Kaynar, Oguz; Yilmaz, Isik; Marschalko, Marian; Bednarik, Martin; Fojtova, Lucie

2013-04-01

Hazen first proposed a Relationship between coefficient of permeability (k) and effective grain size (d10) was first proposed by Hazen, and it was then extended by some other researchers. However many attempts were done for estimation of k, correlation coefficients (R2) of the models were generally lower than ~0.80 and whole grain size distribution curves were not included in the assessments. Soft computing techniques such as; artificial neural networks, fuzzy inference systems, genetic algorithms, etc. and their hybrids are now being successfully used as an alternative tool. In this study, use of some soft computing techniques such as Artificial Neural Networks (ANNs) (MLP, RBF, etc.) and Adaptive Neuro-Fuzzy Inference System (ANFIS) for prediction of permeability of coarse grained soils was described, and Hazen's equation was then modificated. It was found that the soft computing models exhibited high performance in prediction of permeability coefficient. However four different kinds of ANN algorithms showed similar prediction performance, results of MLP was found to be relatively more accurate than RBF models. The most reliable prediction was obtained from ANFIS model.

Mineral resource assessment map of the Big Gum Swamp Roadless Area, Columbia and Baker counties, Florida

USGS Publications Warehouse

Cathcart, J.B.; Cameron, C.C.; Patterson, S.H.

1986-01-01

The geology of the Big Cum Swamp Roadless Area, which is discussed briefly in this report, is covered in somewhat more detail in a report by Patterson, Cathcart, Cameron, and Schruben (1984). The mineral resource potential is quite similar to that in the Natural Area Roadless Area outlined by Cathcart, Patterson and Crandall (1983). The Natural Area, which is east of the eastern boundary of the Big Gum Swamp (fig. 1), also was designated a Wilderness Study Area by Public Law 98-430, September 28, 1984.

Methane production and emissions from four reclaimed and pristine wetlands of Southeastern United States

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

Schipper, L.A.; Reddy, K.R.

Wetlands are significant contributors to global CH[sub 4] emission. We measured CH[sub 4] emissions at two pristine wetlands [Okefenokee swamp and the Everglades (Water Conservation Area 2A)] and two reclaimed wetlands (Sunny Hill Farm and Apopka Marsh) in Southeastern USA, and we attempted to relate emissions to CH[sub 4] production rates of the soil and the soil's biological and chemical properties. Methane emissions through cattail [Typha sp.] and waterilly [Nymphaea ordorata (L.)] ranged from 0.09 to 1.7 g CH[sub 4] m[sup [minus]2] d[sup [minus]1] and exhibited high spatial and temporal variability. Diffusive flux of CH[sub 4] was calculated using dissolvedmore » CH[sub 4] profiles in the soil pore water and accounted for <5% of the plant-mediated emissions. Potential CH[sub 4] production rates were measured as a function of depth using soil samples obtained at 2-cm increments. Methane production rates were the same order of magnitude at all sites (<1-70 ng CH[sub 4]-C g[sup [minus]1] soil C d[sup [minus]1]) and were highest in the surface soils (0-6 cm) at three of the wetland sites, indicating that the predominant source of C available to methanogens was in the surface soils. Methane production rates in the top 24 cm ranged from 0.3 to 1.1 g CH[sub 4] m[sup [minus]2] d[sup [minus]1] and annual C losses due to anaerobic decomposition accounted for between 0.68 and 3.7% of the total C in the surface 24-cm soil depth. 36 refs., 3 figs., 3 tabs.« less

Vegetation, soil, and flooding relationships in a blackwater floodplain forest

USGS Publications Warehouse

Burke, M.K.; King, S.L.; Gartner, D.; Eisenbies, M.H.

2003-01-01

Hydroperiod is considered the primary determinant of plant species distribution in temperate floodplain forests, but most studies have focused on alluvial (sediment-laden) river systems. Few studies have evaluated plant community relationships in blackwater river systems of the South Atlantic Coastal Plain of North America. In this study, we characterized the soils, hydroperiod, and vegetation communities and evaluated relationships between the physical and chemical environment and plant community structure on the floodplain of the Coosawhatchie River, a blackwater river in South Carolina, USA. The soils were similar to previous descriptions of blackwater floodplain soils but had greater soil N and P availability, substantially greater clay content, and lower soil silt content than was previously reported for other blackwater river floodplains. Results of a cluster analysis showed there were five forest communities on the site, and both short-term (4 years) and long-term (50 years) flooding records documented a flooding gradient: water tupelo community > swamp tupelo > laurel oak = overcup oak > mixed oak. The long-term hydrologic record showed that the floodplain has flooded less frequently from 1994 to present than in previous decades. Detrended correspondence analysis of environmental and relative basal area values showed that 27% of the variation in overstory community structure could be explained by the first two axes; however, fitting the species distributions to the DCA axes using Gaussian regression explained 67% of the variation. Axes were correlated with elevation (flooding intensity) and soil characteristics related to rooting volume and cation nutrient availability. Our study suggests that flooding is the major factor affecting community structure, but soil characteristics also may be factors in community structure in blackwater systems. ?? 2003, The Society of Wetland Scientists.

Organic-Carbon Sequestration in Soil/Sediment of the Mississippi River Deltaic Plain - Data; Landscape Distribution, Storage, and Inventory; Accumulation Rates; and Recent Loss, Including a Post-Katrina Preliminary Analysis (Chapter B)

USGS Publications Warehouse

Markewich, Helaine W.; Buell, Gary R.; Britsch, Louis D.; McGeehin, John P.; Robbins, John A.; Wrenn, John H.; Dillon, Douglas L.; Fries, Terry L.; Morehead, Nancy R.

2007-01-01

Soil/sediment of the Mississippi River deltaic plain (MRDP) in southeastern Louisiana is rich in organic carbon (OC). The MRDP contains about 2 percent of all OC in the surface meter of soil/sediment in the Mississippi River Basin (MRB). Environments within the MRDP differ in soil/sediment organic carbon (SOC) accumulation rate, storage, and inventory. The focus of this study was twofold: (1) develop a database for OC and bulk density for MRDP soil/sediment; and (2) estimate SOC storage, inventory, and accumulation rates for the dominant environments (brackish, intermediate, and fresh marsh; natural levee; distributary; backswamp; and swamp) in the MRDP. Comparative studies were conducted to determine which field and laboratory methods result in the most accurate and reproducible bulk-density values for each marsh environment. Sampling methods included push-core, vibracore, peat borer, and Hargis1 sampler. Bulk-density data for cores taken by the 'short push-core method' proved to be more internally consistent than data for samples collected by other methods. Laboratory methods to estimate OC concentration and inorganic-constituent concentration included mass spectrometry, coulometry, and loss-on-ignition. For the sampled MRDP environments, these methods were comparable. SOC storage was calculated for each core with adequate OC and bulk-density data. SOC inventory was calculated using core-specific data from this study and available published and unpublished pedon data linked to SSURGO2 map units. Sample age was estimated using isotopic cesium (137Cs), lead (210Pb), and carbon (14C), elemental Pb, palynomorphs, other stratigraphic markers, and written history. SOC accumulation rates were estimated for each core with adequate age data. Cesium-137 profiles for marsh soil/sediment are the least ambiguous. Levee and distributary 137Cs profiles show the effects of intermittent allochthonous input and/or sediment resuspension. Cesium-137 and 210Pb data gave the most consistent and interpretable information for age estimations of soil/sediment deposited during the 1900s. For several cores, isotopic 14C and 137Cs data allowed the 1963-64 nuclear weapons testing (NWT) peak-activity datum to be placed within a few-centimeter depth interval. In some cores, a too old 14C age (when compared to 137Cs and microstratigraphic-marker data) is the probable result of old carbon bound to clay minerals incorporated into the organic soil/sediment. Elemental Pb coupled with Pb source-function data allowed age estimation for soil/sediment that accumulated during the late 1920s through the 1980s. Exotic pollen (for example, Vigna unguiculata and Alternanthera philoxeroides) and other microstratigraphic indicators (for example, carbon spherules) allowed age estimations for marsh soil/sediment deposited during the settlement of New Orleans (1717-20) through the early 1900s. For this study, MRDP distributary and swamp environments were each represented by only one core, backswamp environment by two cores, all other environments by three or more cores. MRDP core data for the surface meter soil/sediment indicate that (1) coastal marshes, abandoned distributaries, and swamps have regional SOC-storage values >16 kg m-2; (2) swamps and abandoned distributaries have the highest SOC storage values (swamp, 44.8 kg m-2; abandoned distributary, 50.9 kg m-2); (3) fresh-to-brackish marsh environments have the second highest site-specific SOC-storage values; and (4) site-specific marsh SOC storage values decrease as the salinity of the environment increases (fresh-marsh, 36.2 kg m-2; intermediate marsh, 26.2 kg m-2; brackish marsh, 21.5 kg m-2). This inverse relation between salinity and SOC storage is opposite the regional systematic increase in SOC storage with increasing salinity that is evident when SOC storage is mapped by linking pedon data to SSURGO map units (fresh marsh, 47 kg m-2; intermediate marsh, 67 kg m-2; brackish marsh, 75 kg m-2; and salt marsh, 80 kg m-2). MRDP core data for this study also indicate that levees and backswamp have regional SOC-storage values <16 kg m-2. Group-mean SOC storage for cores from these environments are natural levee (17.0 kg m-2) and backswamp (14.1 kg m-2). An estimate for the SOC inventory in the surface meter of soil/sediment in the MRDP can be made using the SSURGO mapped portion of the coastal-marsh vegetative-type map (13,236 km2, land-only area) published by the Louisiana Department of Wildlife and Fisheries and U.S. Geological Survey (1997). This area has a SOC inventory (surface meter) of 677 Tg (slightly more than 2 percent of the 30,289 Tg SOC inventory for the MRB). The MRDP (6,180 km2, land-only area) has an estimated SOC inventory of 397 Tg. Most of the MRDP is located within the SSURGO mapped coastal marshlands. The entire MRDP, including water, has an area of about 10,800 km2. Using the ratio of total MRDP area to SSURGO mapped MRDP area as an adjustment, the MRDP SOC inventory is estimated at 694 Tg. This larger estimate of 694 Tg for the SOC inventory is probably more realistic, because it is reasonable to assume that the marsh sediments overlain by shallow water have comparable SOC storage to that of the adjacent land areas. MRDP core data for this study indicate that there is some variability in long-term SOC mass-accumulation rates for centuries and millennia and that this variability may indicate important geologic changes or changes in land use. However, the consistency of the range in rates of SOC accumulation through time suggests a remarkable degree of marsh sustainability throughout the Holocene, including the recent period of significant marsh modification/channelization for human use. One example of marsh sustainability is its present ability to function as a SOC sink even with Louisiana's large-scale coastal land loss during the last several decades. With coastal-marsh restoration efforts, this sink potential will increase. Looking to the future, a total of 1,101 g m-2 yr-1 SOC is projected to be lost from all of coastal Louisiana (U.S. Army Corps of Engineers, Louisiana Coastal Area (LCA) subprovinces 1-4; not just the MRDP) through coastal erosion from year 2000 to 2050. This translates to a projected SOC-loss rate of about 0.20 percent per year. The recent Hurricanes Katrina and Rita, which devastated the Louisiana coast during late August and late September 2005, transformed about 259 km2 (100 mi2) of marsh to open water (U.S. Geological Survey, 2005). To the extent that some or all of this land loss is permanent, this result equates to a SOC loss of about 15 Tg. This estimate is based on the year-2000 15,153-km2 land area for the LCA study area that includes LCA subprovince 4. Using the year-2000 land area, the LCA study area had an estimated SOC inventory of 858 Tg. The estimated 15 Tg SOC loss attributable to Hurricanes Katrina and Rita is 1.7 percent of the year-2000 LCA inventory and 2.3 percent of the year-2000 MRDP inventory. If this SOC loss is included in the projection for the year 2050, then the MRDP would either remain a source with a net SOC loss of 3 Tg or become a weak sink with a net SOC gain of 4 Tg. These estimates are lower bounds for potential SOC flux because they are only for the surface meter of landmass.

Site Classification using Multichannel Channel Analysis of Surface Wave (MASW) method on Soft and Hard Ground

NASA Astrophysics Data System (ADS)

Ashraf, M. A. M.; Kumar, N. S.; Yusoh, R.; Hazreek, Z. A. M.; Aziman, M.

2018-04-01

Site classification utilizing average shear wave velocity (Vs(30) up to 30 meters depth is a typical parameter. Numerous geophysical methods have been proposed for estimation of shear wave velocity by utilizing assortment of testing configuration, processing method, and inversion algorithm. Multichannel Analysis of Surface Wave (MASW) method is been rehearsed by numerous specialist and professional to geotechnical engineering for local site characterization and classification. This study aims to determine the site classification on soft and hard ground using MASW method. The subsurface classification was made utilizing National Earthquake Hazards Reduction Program (NERHP) and international Building Code (IBC) classification. Two sites are chosen to acquire the shear wave velocity which is in the state of Pulau Pinang for soft soil and Perlis for hard rock. Results recommend that MASW technique can be utilized to spatially calculate the distribution of shear wave velocity (Vs(30)) in soil and rock to characterize areas.

Changing patterns of Pennsylvanian coal-swamp vegetation and implications of climatic control on coal occurrence

USGS Publications Warehouse

Phillips, T.L.; Peppers, R.A.

1984-01-01

Improved regional and interregional stratigraphic correlations of Pennsylvanian strata permit comparisons of vegetational changes in Euramerican coal swamps. The coal-swamp vegetation is known directly from in situ coal-ball peat deposits from more than 65 coals in the United States and Europe. Interpretations of coal-swamp floras on the basis of coal-ball peat studies are extended to broader regional and stratigraphic patterns by use of coal palynology. Objectives of the quantitative analyses of the vegetation in relation to coal are to determine the botanical constituents at the peat stage and their environmental implications for plant growth and peat accumulation. Morphological and paleoecological analyses provide a basis for deducing freshwater regimes of coal swamps. Changes in composition of Pennsylvanian coal-swamp vegetation are quire similar from one paralic coal region to another and show synchrony that is attributable to climate. Paleobotany and paleogeography of the Euramerican province indicate a moist tropical paleoclimate. Rainfall, runoff and evapotranspiration were the variable climatic controls in the distribution of coal-swamp vegetation, peat accumulation and coal resources. In relative terms of climatic wetness the Pennsylvanian Period is divisible into five intervals, which include two relatively drier intervals that developed during the Lower-Middle and Middle-Upper Pennsylvanian transitions. The climate during Early Pennsylvanian time was moderately wet and the median in moisture availability. Early Middle Pennsylvanian was drier, probably seasonally dry-wet; late Middle Pennsylvanian was the wettest in the Midcontinent; early Late Pennsylvanian was the driest; and late Late Pennsylvanian was probably the wettest in the Dunkard Basin. The five climatic intervals represent a general means of dividing coal resources within each region into groups with similar botanical constituents and environments of peat accumulation. Regional differences in basinal geology and climate were significant variables, but the synchronous control of paleoclimate was of primary importance. ?? 1984.

Modeling Human Exposure Risk to Nontuberculous Mycobacteria in Central North Carolina

EPA Science Inventory

Nontuberculous mycobacteria (NTM) are a broad group of soil-and water-borne bacteria. Some species are pathogenic and may cause serious infections in the lungs, soft tissues, bones and skin. Infections in humans are associated with environmental exposures to contaminated soil, ae...

JPL-19670908-SURVEYf-0001-AVC2002083 Surveyor 5 Launches

NASA Image and Video Library

1967-09-08

Launch of Surveyor 5 toward a soft landing on the Moon. Equipped with a chemical element analyzer for conducting analyses of the lunar soil, the Surveyor 5 lander was the first spacecraft to do a soil analysis on the moon, or any other world.

3. Photocopy of a drawing (original in the Collection of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Photocopy of a drawing (original in the Collection of the PL&C, Shelf 141, Drawing 25) --no date--SWAMP LOCKS AND LOCK CHAMBERS - Pawtucket Canal, Swamp Locks, Pawtucket & Merrimack Canals, Lowell, Middlesex County, MA

Dr. Thomas Zurbuchen Visits Swamp Works

NASA Image and Video Library

2016-11-18

Thomas Zurbuchen, in plaid shirt, NASA's associate administrator for the Science Mission Directorate, listens to a presentation at the Swamp Works facility at NASA's Kennedy Space Center in Florida. In the foreground is a prototype robotic exploration vehicle.

SwampLog: A Structured Journal for Reflection-in-Action.

ERIC Educational Resources Information Center

Nicassio, Frank

1992-01-01

Describes "SwampLog," an action-research journal process useful for recording and reflecting upon ongoing experience, exploring and creating innovative approaches to education, and gauging the resultant effects upon organizational, instructional, and individual renewal. (PRA)

Palynology and organic/isotope geochemistry of the Mae Moh Basin, Northern Thailand

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

Minh, L.V.; Abrajano, T.; Burden, E.

The Mae Moh basin is one of several Tertiary intermontane basins in northern Thailand, whose evolution has been linked to the collision of the Indian plate with the Eurasian plate since the early Eocene. As in most of these basins, lacustrine/swamp sedimentation in the Mae Moh basin can be broadly divided into an Oligocene to Miocene synrift sequence and a Miocene to Quarternary postrift sequence. The dominance of swamp flora recognized from spore and pollen assemblages (e.g., Polypodiidites usmensis, Verrucatosporites, Cyrtostachys), as well as the abundance of macrophytes and woody debris, indicate overwhelming hot and humid swamp conditions, with lakemore » development restricted to relatively small areas. The distribution of alkanes and their compound-specific carbon isotope compositions are used to further show climatic variations affecting the lake/swamp ecology during the deposition of the synrift sequence.« less

Ecology of red maple swamps in the glaciated northeast: A community profile

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

Golet, F.C.; Calhoun, A.J.K.; DeRagon, W.R.

1993-06-01

In many areas of the glaciated northeastern United States, forested wetlands dominated by red maple (Acer rubrum) cover more of the landscape than all other nontidal wetland types combined. Yet surprisingly little of their ecology, functions, or social significance has been documented. Bogs, salt marshes, Atlantic white cedar swamps, and other less common types of wetlands have received considerable attention from scientists, but, except for botanical surveys, red maple swamps have been largely ignored. The report conveys what is known about these common wetlands and identifies topics most in need of investigation. Red maple swamps are so abundant and somore » widely distributed in the Northeast that their physical, chemical, and biological properties range widely as well, and their values to society are diverse. The central focus of the U.S. Fish and Wildlife Service community profile series is the plant and animal communities of wetlands and deepwater habitats.« less

[Use and conservation of palm swamps Raphia taedigera (Arecaceae) in the Area de Conservación Tortuguero, Costa Rica].

PubMed

Calvo-Gutiérrez, Carlos M; Bonilla-Murillo, Fabián; Sasa, Mahmood

2013-09-01

The swamps dominated by raffia palm Raphia taedigera are conspicuous environments in the Tortuguero floodplains and in other wet regions along the Caribbean and Pacific coasts of Costa Rica. However, these environments have been little studied and are exposed to numerous threats, most importantly their replacement by agricultural activities or pastureland. In this paper, we describe some applications and uses of the raffia palms and other palms that are common in these flooded swamps. We also describe the efforts that have been made in Costa Rica for the protection or raffia-dominated swamps, through the environmental law frame of the country and the establishment of a protection system based on wilderness areas under different categories of protection. We discuss issues relevant to the future of these environments in the regions where they are distributed.

Lateral carbon fluxes and CO2 outgassing from a tropical peat-draining river

NASA Astrophysics Data System (ADS)

Müller, D.; Warneke, T.; Rixen, T.; Müller, M.; Jamahari, S.; Denis, N.; Mujahid, A.; Notholt, J.

2015-10-01

Tropical peatlands play an important role in the global carbon cycle due to their immense carbon storage capacity. However, pristine peat swamp forests are vanishing due to deforestation and peatland degradation, especially in Southeast Asia. CO2 emissions associated with this land use change might not only come from the peat soil directly but also from peat-draining rivers. So far, though, this has been mere speculation, since there has been no data from undisturbed reference sites. We present the first combined assessment of lateral organic carbon fluxes and CO2 outgassing from an undisturbed tropical peat-draining river. Two sampling campaigns were undertaken on the Maludam River in Sarawak, Malaysia. The river catchment is covered by protected peat swamp forest, offering a unique opportunity to study a peat-draining river in its natural state, without any influence from tributaries with different characteristics. The two campaigns yielded consistent results. Dissolved organic carbon (DOC) concentrations ranged between 3222 and 6218 μmol L-1 and accounted for more than 99 % of the total organic carbon (TOC). Radiocarbon dating revealed that the riverine DOC was of recent origin, suggesting that it derives from the top soil layers and surface runoff. We observed strong oxygen depletion, implying high rates of organic matter decomposition and consequently CO2 production. The measured median pCO2 was 7795 and 8400 μatm during the first and second campaign, respectively. Overall, we found that only 32 ± 19 % of the carbon was exported by CO2 evasion, while the rest was exported by discharge. CO2 outgassing seemed to be moderated by the short water residence time. Since most Southeast Asian peatlands are located at the coast, this is probably an important limiting factor for CO2 outgassing from most of its peat-draining rivers.

Electrokinetic Stabilisation Method of Soft Clay in Pure System using Electrokinetic Geosynthetic Electrode

NASA Astrophysics Data System (ADS)

Azhar, A. T. S.; Jefferson, I.; Madun, A.; Abidin, M. H. Z.; Rogers, C. D. F.

2018-04-01

Electrokinetic stabilisation (EKS) method has the ability to solve the problems of soft highly compressibility soil. This study will present the results from an experimental study of EKS on soft soils using inactive kaolinite clay, inert electrode and distilled water (DW) as a pure system mechanism before any chemical stabilisers being used in this research. Therefore, this will provide a baseline study to improve the efficiency of EKS approach. The test model was using inert electrode of Electrokinetic Geosythentic (EKG) developed at the Newcastle University to apply a constant voltage gradient of 50 V/m across a soil sample approximately 400 mm. Distilled water was used at the pore electrolyte fluid compartments supplied under zero hydraulic gradient conditions for the periods of 3, 7 and 14 days. Throughout the monitoring, physical and chemical characteristics were measured. Results from the monitoring data, physical and chemical properties of the pure system showed the development of pH gradient, the changes of electrical conductivity and chemical concentrations with regards to the distance from anode and treatment periods due to the electrochemical effects even though there was no chemical stabilisers were introduced or released from the degradation of electrodes.

Effects of trichostatin A on In vitro development and DNA methylation level of the satellite I region of swamp buffalo (Bubalus bubalis) cloned embryos.

PubMed

Srirattana, Kanokwan; Ketudat-Cairns, Mariena; Nagai, Takashi; Kaneda, Masahiro; Parnpai, Rangsun

2014-01-01

Trichostatin A (TSA), a histone deacetylase inhibitor, has been widely used to improve the cloning efficiency in several species. This brings our attention to investigation of the effects of TSA on developmental potential of swamp buffalo cloned embryos. Swamp buffalo cloned embryos were produced by electrical pulse fusion of male swamp buffalo fibroblasts with swamp buffalo enucleated oocytes. After fusion, reconstructed oocytes were treated with 0, 25 or 50 nM TSA for 10 h. The results showed that there was no significant difference in the rates of fusion (82-85%), cleavage (79-84%) and development to the 8-cell stage (59-65%) among treatment groups. The highest developmental rates to the morula and blastocyst stages of embryos were found in the 25 nM TSA-treated group (42.7 and 30.1%, respectively). We also analyzed the DNA methylation level in the satellite I region of donor cells and in in vitro fertilized (IVF) and cloned embryos using the bisulfite DNA sequencing method. The results indicated that the DNA methylation levels in cloned embryos were significantly higher than those of IVF embryos but approximately similar to those of donor cells. Moreover, there was no significant difference in the methylation level among TSA-treated and untreated cloned embryos. Thus, TSA treatments at 25 nM for 10 h could enhance the in vitro developmental potential of swamp buffalo cloned embryos, but no beneficial effect on the DNA methylation level was observed.

Effects of Trichostatin A on In Vitro Development and DNA Methylation Level of the Satellite I Region of Swamp Buffalo (Bubalus bubalis) Cloned Embryos

PubMed Central

SRIRATTANA, Kanokwan; KETUDAT-CAIRNS, Mariena; NAGAI, Takashi; KANEDA, Masahiro; PARNPAI, Rangsun

2014-01-01

Trichostatin A (TSA), a histone deacetylase inhibitor, has been widely used to improve the cloning efficiency in several species. This brings our attention to investigation of the effects of TSA on developmental potential of swamp buffalo cloned embryos. Swamp buffalo cloned embryos were produced by electrical pulse fusion of male swamp buffalo fibroblasts with swamp buffalo enucleated oocytes. After fusion, reconstructed oocytes were treated with 0, 25 or 50 nM TSA for 10 h. The results showed that there was no significant difference in the rates of fusion (82–85%), cleavage (79–84%) and development to the 8-cell stage (59–65%) among treatment groups. The highest developmental rates to the morula and blastocyst stages of embryos were found in the 25 nM TSA-treated group (42.7 and 30.1%, respectively). We also analyzed the DNA methylation level in the satellite I region of donor cells and in in vitro fertilized (IVF) and cloned embryos using the bisulfite DNA sequencing method. The results indicated that the DNA methylation levels in cloned embryos were significantly higher than those of IVF embryos but approximately similar to those of donor cells. Moreover, there was no significant difference in the methylation level among TSA-treated and untreated cloned embryos. Thus, TSA treatments at 25 nM for 10 h could enhance the in vitro developmental potential of swamp buffalo cloned embryos, but no beneficial effect on the DNA methylation level was observed. PMID:24909601

Compaction and Plasticity Comparative Behaviour of Soft Clay Treated with Coarse and Fine Sizes of Ceramic Tiles

NASA Astrophysics Data System (ADS)

Al-Bared, Mohammed Ali Mohammed; Marto, Aminaton; Sati Hamonangan Harahap, Indra; Kasim, Fauziah

2018-03-01

Recycled blended ceramic tiles (RBT) is a waste material produced from ceramic tile factories and construction activities. RBT is found to be cost effective, sustainable, environmental-friendly and has the potential to be used as an additive in soft soil stabilization. Recent reports show that massive amounts of RBT are dumped into legal or illegal landfills every year consuming very large spaces and creating major environmental problems. On the other hand, dredged marine clay obtained from Nusajaya, Johor, Malaysia has weak physical and engineering characteristics to be considered as unsuitable soft soil that is usually excavated, dumped into landfills and replaced by stiff soil. Hence, this study investigates the suitability of possible uses of RBT to treat marine clay. Laboratory tests included Standard proctor tests and Atterberg limits tests. The plasticity of marine clay was evaluated by adding 10%, 20%, 30% and 40% of 0.3 mm RBT. In addition, the compaction behaviour of treated marine clay was compared by adding two different sizes (0.3 mm and 1.18 mm diameter) of RBT. For both coarse and fine sizes of RBT, 10%, 20%, 30% and 40% of the dry weight of the soft clay were added. The mixture of each combination was examined in order to evaluate the Maximum Dry Density (MDD) and the optimum moisture content (OMC) for the treated soft clay. MDD and OMC for soft untreated samples were 1.59 Mg/m3 and 22%, respectively. Treated samples with 10%, 20%, 30% and 40% of 0.30 mm size RBT resulted in a significant reduction of OMC ranged from 19 to 15% while MDD resulted in increment ranged from 1.69 to 1.77 Mg/m3. In addition, samples treated with 10%, 20%, 30% and 40% of 1.18 mm size RBT resulted in major reduction of OMC ranged from 15 to 13.5% while MDD increased effectively from 1.75 to 1.82 Mg/m3. For all mix designs of soft clay-RBT, MDD was gradually increasing and OMC was sharply reducing with further increments of both sizes of RBT.

Hydrologic Linkages Between Floodplain Wetlands and Adjacent Agricultural Lands

NASA Astrophysics Data System (ADS)

Matteson, C.; Jackson, C. R.; Wilde, S. B.; Batzer, D.; Shelton, J.; Jeffers, J. B.

2017-12-01

Depending on wetland position relative to dominant flow pathways, wetlands can provide biogeochemical processing and water quality improvement in agricultural settings, particularly with respect to nutrients. Here we evaluate field-to-stream water quality gradients across a forested alluvial swamp and through a ditched wetland swale on the same site. During 2016 and 2017, water samples collected on a farm from shallow piezometers and surface water were analyzed for total oxidized nitrogen (TOxN), total phosphorus (TP), and microbial abundance. A 54-acre alluvial swamp borders the northern side of the study farm. Toeslope nutrient concentrations in shallow groundwater and surfacewater are elevated relative to background levels, with median values of 13.25 mg/l/TOxN and 47.60 µg/l/TP. Shallow groundwater and surfacewater concentrations are substantially lower only a few meters into the floodplain wetland and lower still (0.13 mg/l/TOxN and 29.67 µg/l/TP) at discharge points to an adjacent creek. Across the farm, an 18-acre wetland swale has been ditched, drained, and cropped. TOxN levels entering and exiting the ditched swale do not mitigate as efficiently, median values of 3.91 mg/l/TOxN reduce to 1.45 mg/l/TOxN, while TP input and reduction exceed the alluvial swamp by starting at 141.67 µg/l/TP at the inflow and discharging into a large river at 57.40 µg/l/TP. Microbial communities in seeps and surfacewater also vary systematically with geographic position. Higher proportions of Cyanobacteria, Turbidity indicators, and Diatom communities are observed in the ditched swale, and input areas of the alluvial swamp. ANOVA tests of TOxN (P<0.001) and TP (P=0.9) change across the alluvial swamp suggest effective processing of TOxN. While P values for TOxN and TP in the ditched swale, yield P=0.9 for TOxN and P=1.0 for TP indicating reduced efficiency of mitigation. Though values of both TOxN and TP do decrease before discharge into the river, they are not statistically significant and still greater values than the alluvial swamp. Dissipation of microbial indicators shows pollution mitigation further into the alluvial swamp. Though pollutant additions have been similar into both wetland types, water quality improvements are distinct in the alluvial swamp.

The hydraulic geometry of narrow and deep channels; evidence for flow optimisation and controlled peatland growth

NASA Astrophysics Data System (ADS)

Nanson, Rachel A.; Nanson, Gerald C.; Huang, He Qing

2010-04-01

At-a-station and bankfull hydraulic geometry analyses of peatland channels at Barrington Tops, New South Wales, Australia, reveal adjustments in self-forming channels in the absence of sediment load. Using Rhodes ternary diagram, comparisons are made with hydraulic geometry data from self-forming channels carrying bedload in alluvial settings elsewhere. Despite constraints on channel depths caused at some locations by the restricted thickness of peat, most stations have cohesive, near-vertical, well-vegetated banks, and width/depth (w/d) ratios of ∼ 2 that are optimal for sediment-free flow. Because banks are strong, resist erosion and can stand nearly vertical, and depth is sometimes constrained, adjustments to discharge are accommodated largely by changes in velocity. These findings are consistent with the model of maximum flow efficiency and the overarching least action principle in open channels. The bankfull depth of freely adjusting laterally active channels in clastic alluvium is well known to be related to the thickness of floodplain alluvium and a similar condition appears to apply to these swamps that grow in situ and are formed almost entirely of organic matter. The thickness of peat in these swamps rarely exceeds that required to form a bankfull channel of optimum w/d ratio for the transport of sediment-free water. Swamp vegetation is highly dependent on proximity to the water table. To maintain a swamp-channel and associated floodplain system, the channels must flow with sufficient water much of the time; they not only offer an efficient morphology for flow but do so in a way that enables bankfull conditions to occur many times a year. They also prevent the swamp from growing above a level linked to the depth of the channel. Once the channel attains the most efficient cross section, further growth of the swamp vertically is restricted by enhanced flow velocities and limited flow depths. This means that the volume of peat in such swamps is determined by the hydraulic efficiency of their channels. The development and maintenance of the hydraulic geometry of these swamp channels is biogeomorphic and biohydraulic in nature and yet accords to the same optimising principles that govern the formation of self-adjusting channels and floodplains in clastic alluvium.

Surface pavement solutions for poor subgrade conditions phase II : performance analysis of test sections and implementation guidelines : summary.

DOT National Transportation Integrated Search

2010-12-01

Several areas within FDOT Districts 4 and 6 contain thick layers of organic soils at relatively shallow depths. Roads built on these soft compressible soils : often develop premature cracking, distortion, and settlement. Traditional repair methods, s...

[Interrelations between plant communities and environmental factors of wetlands and surrounding lands in mid- and lower reaches of Tarim River].

PubMed

Zhao, Ruifeng; Zhou, Huarong; Qian, Yibing; Zhang, Jianjun

2006-06-01

A total of 16 quadrants of wetlands and surrounding lands in the mid- and lower reaches of Tarim River were surveyed, and the data about the characteristics of plant communities and environmental factors were collected and counted. By using PCA (principal component analysis) ordination and regression procedure, the distribution patterns of plant communities and the relationships between the characteristics of plant community structure and environmental factors were analyzed. The results showed that the distribution of the plant communities was closely related to soil moisture, salt, and nutrient contents. The accumulative contribution rate of soil moisture and salt contents in the first principal component accounted for 35.70%, and that of soil nutrient content in the second principal component reached 25.97%. There were 4 types of habitats for the plant community distribution, i. e., fenny--light salt--medium nutrient, moist--medium salt--medium nutrient, mesophytic--medium salt--low nutrient, and medium xerophytic-heavy salt--low nutrient. Along these habitats, swamp vegetation, meadow vegetation, riparian sparse forest, halophytic desert, and salinized shrub were distributed. In the wetlands and surrounding lands of mid- and lower reaches of Tarim River, the ecological dominance of the plant communities was markedly and unitary-linearly correlated with the compound gradient of soil moisture and salt contents. The relationships between species diversity, ecological dominance, and compound gradient of soil moisture and salt contents were significantly accorded to binary-linear regression model.

Multi-Terrain Vertical Drop Tests of a Composite Fuselage Section

NASA Technical Reports Server (NTRS)

Kellas, Sotiris; Jackson, Karen E.

2008-01-01

A 5-ft-diameter composite fuselage section was retrofitted with four identical blocks of deployable honeycomb energy absorber and crash tested on two different surfaces: soft soil, and water. The drop tests were conducted at the 70-ft. drop tower at the Landing and Impact Research (LandIR) Facility of NASA Langley. Water drop tests were performed into a 15-ft-diameter pool of water that was approximately 42-in. deep. For the soft soil impact, a 15-ft-square container filled with fine-sifted, unpacked sand was located beneath the drop tower. All drop tests were vertical with a nominally flat attitude with respect to the impact surface. The measured impact velocities were 37.4, and 24.7-fps for soft soil and water, respectively. A fuselage section without energy absorbers was also drop tested onto water to provide a datum for comparison with the test, which included energy absorbers. In order to facilitate this type of comparison and to ensure fuselage survivability for the no-energy-absorber case, the velocity of the water impact tests was restricted to 25-fps nominal. While all tests described in this paper were limited to vertical impact velocities, the implications and design challenges of utilizing external energy absorbers during combined forward and vertical impact velocities are discussed. The design, testing and selection of a honeycomb cover, which was required in soft surface and water impacts to transmit the load into the honeycomb cell walls, is also presented.

4. Photocopy of a drawing (original in the Collection of ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. Photocopy of a drawing (original in the Collection of the PL&C, Shelf 144, Drawing 13) SECTIONS OF LOCK CHAMBERS AT SWAMP LOCKS DAM, APRIL 1890 - Pawtucket Canal, Swamp Locks, Pawtucket & Merrimack Canals, Lowell, Middlesex County, MA

Content of radionuclides in the peat deposit of swamps

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

Nifontova, M.G.; Makovskii, V.I.

1995-11-01

The results are given of comparative analysis of the content and transformation of {sup 90}Sr and {sup 137}Cs over a peat deposit of swamps. During radioecological study, account was taken of the quantitative composition and physicochemical properties of the peat, as well as of the specific nature of the entry of radioactive products to peat deposits. Considering the increased capacity of peat for accumulating radionuclides and the specific features of sorption processes in a peat deposit, it is expedient to utilize swamps as a convenient natural object for continuous monitoring of radioactive contamination of the environment.

Arsenic in groundwater of the Paraiba do Sul delta, Brazil: An atmospheric source?

PubMed

Mirlean, N; Baisch, P; Diniz, D

2014-06-01

High concentrations of arsenic (>50μg L(-1)) have been detected for the first time in groundwater of the wave-dominated Paraiba do Sul delta, Brazil. The deltaic shallow groundwater aquifer is enriched in arsenic fixed by authigenic sulfides. A study of palynomorphs confirmed that aquifer sediments were formed in inter-dune lakes/swamps lately covered by eolian sands. The organic sediments of contemporaneous inter-dune lake/swamp contain very high concentration of As: up to 180mg kg(-1) and 163μg L(-1) in dry gyttja material and interstitial water, respectively. The As in recent lake/swamp sediments is retained by iron hydroxides in upper and probably by sulfides in lower layers. In the absence of connection of inter-dune lakes/swamps with fluvial currents, the atmospheric input of As could be considered as the principal source in sediments. The calculation demonstrates the possibility of high concentrations of As accumulation in sediments of inter-dune lakes/swamps from atmospheric precipitations within several centuries before they will be covered by eolian sands and turned into shallow aquifer. Considering the commonalities of wave-dominated delta formations, we can predict more prevalent As accumulation in delta plain groundwater. Copyright © 2014 Elsevier B.V. All rights reserved.

First record of epizootic ulcerative syndrome from the Upper Congo catchment: An outbreak in the Bangweulu swamps, Zambia.

PubMed

Huchzermeyer, C F; Huchzermeyer, K D A; Christison, K W; Macey, B M; Colly, P A; Hang'ombe, B M; Songe, M M

2018-01-01

We report on the first outbreak of epizootic ulcerative syndrome (EUS) amongst wild fish populations in the Bangweulu swamps, an inland delta, in the north of Zambia during 2014. The area supports a large and diverse fish fauna related to, but distinct from, that of the Zambezi River system where EUS outbreaks have occurred since 2006. A sizeable artisanal fishery, based on extensive fish weirs, is sustained by the annual flooding of the swamps, and observations of the disease outbreak by fishermen were recorded. Signs typical of infection with Aphanomyces invadans were observed in a number of species. Clinical observations, histology and molecular diagnostic methods were used to confirm infection with A. invadans in two of the most commonly and severely affected species. Several features of the wetland may have contributed to the outbreak and the annual recurrence of the disease. Modes by which the disease may have been introduced into the swamps are discussed. The outbreak is of great significance as the Bangweulu swamps drain into the Congo River in neighbouring Democratic Republic of Congo, Africa's largest drainage system with an extensive and diverse fish fauna previously unaffected by EUS. © 2017 John Wiley & Sons Ltd.

Quantifying soil carbon loss and uncertainty from a peatland wildfire using multi-temporal LiDAR

USGS Publications Warehouse

Reddy, Ashwan D.; Hawbaker, Todd J.; Wurster, F.; Zhu, Zhiliang; Ward, S.; Newcomb, Doug; Murray, R.

2015-01-01

Peatlands are a major reservoir of global soil carbon, yet account for just 3% of global land cover. Human impacts like draining can hinder the ability of peatlands to sequester carbon and expose their soils to fire under dry conditions. Estimating soil carbon loss from peat fires can be challenging due to uncertainty about pre-fire surface elevations. This study uses multi-temporal LiDAR to obtain pre- and post-fire elevations and estimate soil carbon loss caused by the 2011 Lateral West fire in the Great Dismal Swamp National Wildlife Refuge, VA, USA. We also determine how LiDAR elevation error affects uncertainty in our carbon loss estimate by randomly perturbing the LiDAR point elevations and recalculating elevation change and carbon loss, iterating this process 1000 times. We calculated a total loss using LiDAR of 1.10 Tg C across the 25 km2 burned area. The fire burned an average of 47 cm deep, equivalent to 44 kg C/m2, a value larger than the 1997 Indonesian peat fires (29 kg C/m2). Carbon loss via the First-Order Fire Effects Model (FOFEM) was estimated to be 0.06 Tg C. Propagating the LiDAR elevation error to the carbon loss estimates, we calculated a standard deviation of 0.00009 Tg C, equivalent to 0.008% of total carbon loss. We conclude that LiDAR elevation error is not a significant contributor to uncertainty in soil carbon loss under severe fire conditions with substantial peat consumption. However, uncertainties may be more substantial when soil elevation loss is of a similar or smaller magnitude than the reported LiDAR error.

A cost-efficient method to assess carbon stocks in tropical peat soil

NASA Astrophysics Data System (ADS)

Warren, M. W.; Kauffman, J. B.; Murdiyarso, D.; Anshari, G.; Hergoualc'h, K.; Kurnianto, S.; Purbopuspito, J.; Gusmayanti, E.; Afifudin, M.; Rahajoe, J.; Alhamd, L.; Limin, S.; Iswandi, A.

2012-11-01

Estimation of belowground carbon stocks in tropical wetland forests requires funding for laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple analytical tools to assist belowground carbon estimation where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (kgC m-3; Cd) as a function of bulk density (gC cm-3; Bd), which can be used to rapidly estimate belowground carbon storage using Bd measurements only. Predicted carbon densities and stocks are compared with those obtained from direct carbon analysis for ten peat swamp forest stands in three national parks of Indonesia. Analysis of soil carbon density and bulk density from the literature indicated a strong linear relationship (Cd = Bd × 495.14 + 5.41, R2 = 0.93, n = 151) for soils with organic C content > 40%. As organic C content decreases, the relationship between Cd and Bd becomes less predictable as soil texture becomes an important determinant of Cd. The equation predicted belowground C stocks to within 0.92% to 9.57% of observed values. Average bulk density of collected peat samples was 0.127 g cm-3, which is in the upper range of previous reports for Southeast Asian peatlands. When original data were included, the revised equation Cd = Bd × 468.76 + 5.82, with R2 = 0.95 and n = 712, was slightly below the lower 95% confidence interval of the original equation, and tended to decrease Cd estimates. We recommend this last equation for a rapid estimation of soil C stocks for well-developed peat soils where C content > 40%.

Effects of Sea Level Rise and Coastal Marsh Transgression on Soil Organic Matter in a Chesapeake Bay Salt Marsh

NASA Astrophysics Data System (ADS)

Van Allen, R.; Schreiner, K. M.; Guntenspergen, G. R.

2016-12-01

Salt marsh, mangrove swamp, and seagrass bed ecosystems comprise a global carbon stock known as "blue carbon." While vegetated coastal ecosystems have a small global areal extent, their total carbon burial rates are comparable to global marine carbon burial rates. Under global climate change-induced sea level rise, the role of these systems in the global carbon cycle could change significantly. This study aims to develop a more complete view of how coastal marsh transgression into terrestrial upland environments impacts soil organic matter characteristics. A US Geological Survey study site in Blackwater National Wildlife Refuge on the eastern coast of Chesapeake Bay, Maryland was chosen for this study. This marsh has undergone transgression into adjacent upland forest as local relative sea level has risen, making it an ideal location to study the source and stability of organic matter underlying the shifting marsh-forest boundary. Peat cores and vegetation samples were collected from the study site in May 2015 and June 2016. Care was taken to sample marsh soils underlying a range of elevations and vegetation types from the intertidal zone through the transition to upland forest. Radiocarbon and lead-210 dating give age estimates for basal peat layers within the cores. Analysis of stable carbon isotopes in bulk soils in this site suggests a broad shift towards C4-dominated marsh vegetation. Finally, cupric oxide oxidation products of soil organic matter provide information about the changing molecular organic geochemistry of the marsh soils as sea level rises and the marsh transgresses. This represents a novel molecular-level study of the changing organic geochemistry of marsh soils with sea level rise and resulting vegetation changes.

Climate Controls on Carbon Sequestration in Eastern North America

NASA Technical Reports Server (NTRS)

Peteet, D. M.; Renik, B.; Maenza-Gmeich, T.; Kurdyla, D.; Guilderson, T.

2002-01-01

Mid-latitude forest ecosystems have been proposed as a "missing sink" today. The role of soils (including wetlands) in this proposed sink is a very important unknown. In order to make estimates of future climate change effects on carbon storage, we can examine past wetland carbon sequestration. How did past climate change affect net wetland carbon storage? We present long-term data from existing wetland sites used for paleoclimate reconstruction to assess the net carbon storage in wetland over the last 15000 years. During times of colder and wetter climate, many mid-latitude sites show increases in carbon storage, while past warmer, drier climates produced decreases in storage. Comparison among bog, fen, swamp, and tidal marsh are demonstrated for the Hudson Valley region.

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...

Code of Federal Regulations, 2014 CFR

2014-01-01

...), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders (farcy), acute... poisoning), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders... osteoporosis. (13) Glanders (farcy). (14) Acute inflammatory lameness. (15) Extensive fistula. (b) Carcasses of...

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...

Code of Federal Regulations, 2012 CFR

2012-01-01

...), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders (farcy), acute... poisoning), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders... osteoporosis. (13) Glanders (farcy). (14) Acute inflammatory lameness. (15) Extensive fistula. (b) Carcasses of...

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...

Code of Federal Regulations, 2010 CFR

2010-01-01

...), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders (farcy), acute... poisoning), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders... osteoporosis. (13) Glanders (farcy). (14) Acute inflammatory lameness. (15) Extensive fistula. (b) Carcasses of...

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...

Code of Federal Regulations, 2013 CFR

2013-01-01

...), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders (farcy), acute... poisoning), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders... osteoporosis. (13) Glanders (farcy). (14) Acute inflammatory lameness. (15) Extensive fistula. (b) Carcasses of...

9 CFR 311.10 - Anaplasmosis, anthrax, babesiosis, bacillary hemoglobinuria in cattle, blackleg, bluetongue...

Code of Federal Regulations, 2011 CFR

2011-01-01

...), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders (farcy), acute... poisoning), infectious anemia (swamp fever), dourine, acute influenza, generalized osteoporosis, glanders... osteoporosis. (13) Glanders (farcy). (14) Acute inflammatory lameness. (15) Extensive fistula. (b) Carcasses of...

Deep instability of deforested tropical peatlands revealed by fluvial organic carbon fluxes.

PubMed

Moore, Sam; Evans, Chris D; Page, Susan E; Garnett, Mark H; Jones, Tim G; Freeman, Chris; Hooijer, Aljosja; Wiltshire, Andrew J; Limin, Suwido H; Gauci, Vincent

2013-01-31

Tropical peatlands contain one of the largest pools of terrestrial organic carbon, amounting to about 89,000 teragrams (1 Tg is a billion kilograms). Approximately 65 per cent of this carbon store is in Indonesia, where extensive anthropogenic degradation in the form of deforestation, drainage and fire are converting it into a globally significant source of atmospheric carbon dioxide. Here we quantify the annual export of fluvial organic carbon from both intact peat swamp forest and peat swamp forest subject to past anthropogenic disturbance. We find that the total fluvial organic carbon flux from disturbed peat swamp forest is about 50 per cent larger than that from intact peat swamp forest. By carbon-14 dating of dissolved organic carbon (which makes up over 91 per cent of total organic carbon), we find that leaching of dissolved organic carbon from intact peat swamp forest is derived mainly from recent primary production (plant growth). In contrast, dissolved organic carbon from disturbed peat swamp forest consists mostly of much older (centuries to millennia) carbon from deep within the peat column. When we include the fluvial carbon loss term, which is often ignored, in the peatland carbon budget, we find that it increases the estimate of total carbon lost from the disturbed peatlands in our study by 22 per cent. We further estimate that since 1990 peatland disturbance has resulted in a 32 per cent increase in fluvial organic carbon flux from southeast Asia--an increase that is more than half of the entire annual fluvial organic carbon flux from all European peatlands. Our findings emphasize the need to quantify fluvial carbon losses in order to improve estimates of the impact of deforestation and drainage on tropical peatland carbon balances.

Strong and stable geographic differentiation of swamp buffalo maternal and paternal lineages indicates domestication in the China/Indochina border region.

PubMed

Zhang, Yi; Lu, Yongfang; Yindee, Marnoch; Li, Kuan-Yi; Kuo, Hsiao-Yun; Ju, Yu-Ten; Ye, Shaohui; Faruque, Md Omar; Li, Qiang; Wang, Yachun; Cuong, Vu Chi; Pham, Lan Doan; Bouahom, Bounthong; Yang, Bingzhuang; Liang, Xianwei; Cai, Zhihua; Vankan, Dianne; Manatchaiworakul, Wallaya; Kowlim, Nonglid; Duangchantrasiri, Somphot; Wajjwalku, Worawidh; Colenbrander, Ben; Zhang, Yuan; Beerli, Peter; Lenstra, Johannes A; Barker, J Stuart F

2016-04-01

The swamp type of the Asian water buffalo is assumed to have been domesticated by about 4000 years BP, following the introduction of rice cultivation. Previous localizations of the domestication site were based on mitochondrial DNA (mtDNA) variation within China, accounting only for the maternal lineage. We carried out a comprehensive sampling of China, Taiwan, Vietnam, Laos, Thailand, Nepal and Bangladesh and sequenced the mtDNA Cytochrome b gene and control region and the Y-chromosomal ZFY, SRY and DBY sequences. Swamp buffalo has a higher diversity of both maternal and paternal lineages than river buffalo, with also a remarkable contrast between a weak phylogeographic structure of river buffalo and a strong geographic differentiation of swamp buffalo. The highest diversity of the swamp buffalo maternal lineages was found in south China and north Indochina on both banks of the Mekong River, while the highest diversity in paternal lineages was in the China/Indochina border region. We propose that domestication in this region was later followed by introgressive capture of wild cows west of the Mekong. Migration to the north followed the Yangtze valley as well as a more eastern route, but also involved translocations of both cows and bulls over large distances with a minor influence of river buffaloes in recent decades. Bayesian analyses of various migration models also supported domestication in the China/Indochina border region. Coalescence analysis yielded consistent estimates for the expansion of the major swamp buffalo haplogroups with a credibility interval of 900 to 3900 years BP. The spatial differentiation of mtDNA and Y-chromosomal haplotype distributions indicates a lack of gene flow between established populations that is unprecedented in livestock. © 2015 John Wiley & Sons Ltd.

Low ash, planar peat swamp development in an alluvial plain setting: The No. 5 block beds of southern West Virginia

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

Staub, J.R.; Richards, B.K.

1992-01-01

Coals from the No. 5 Block beds (Westphalian D) are noted for their low ash and sulfur content. Beds are multiple benched, with rock partings separating individual benches. Benches have limited continuity and, where thick are dominated by bright, high ash coal at the base and dull, low ash coal in their upper portions. The duller coals contain more exinite and inertinite group macerals than the brighter coals. The depositional setting is an alluvial plain environment with channel systems separated by distances of about 20 km. The channel systems were flanked by clastic swamps for distances of up to 7more » km or more on either side. Areas of flood plain most distant from the channels were sites where peat accumulated and these zones were about 8 km across. High energy, low frequency flood events introduced fine grained sediment into the peat swamps resulting in thin layers of sediment being deposited on top of the peat. These sediment layers are thicker in areas where the underlying coal is the thickest. These thick coal areas are topographically negative. This relationship between coal and parting thickness and topography indicates that these peat swamps were low-lying or planar. Individual coal benches contain abundant amounts of preserved cellular tissue (telocollinite, semifusinite, fusinite) at most locations indicating that woody arborescent like vegetation was widespread in the swamps suggesting a planar morphology. The high concentrations of exinite and inertinite group macerals found in the upper portions of individual benches resulted from decomposition and oxidation of the peat in subaerial to aquatic planar swamp environments.« less

Survey of Hylobates agilis albibarbis in a logged peat-swamp forest: Sabangau catchment, Central Kalimantan.

PubMed

Buckley, Cara; Nekaris, K A I; Husson, Simon John

2006-10-01

Few data are available on gibbon populations in peat-swamp forest. In order to assess the importance of this habitat for gibbon conservation, a population of Hylobates agilis albibarbis was surveyed in the Sabangau peat-swamp forest, Central Kalimantan, Indonesia. This is an area of about 5,500 km(2) of selectively logged peat-swamp forest, which was formally gazetted as a national park during 2005. The study was conducted during June and July 2004 using auditory sampling methods. Five sample areas were selected and each was surveyed for four consecutive days by three teams of researchers at designated listening posts. Researchers recorded compass bearings of, and estimated distances to, singing groups. Nineteen groups were located. Population density is estimated to be 2.16 (+/-0.46) groups/km(2). Sightings occurring either at the listening posts or that were obtained by tracking in on calling groups yielded a mean group size of 3.4 individuals, hence individual gibbon density is estimated to be 7.4 (+/-1.59) individuals/km(2). The density estimates fall at the mid-range of those calculated for other gibbon populations, thus suggesting that peat-swamp forest is an important habitat for gibbon conservation in Borneo. A tentative extrapolation of results suggests a potential gibbon population size of 19,000 individuals within the mixed-swamp forest habitat sub-type in the Sabangau. This represents one of the largest remaining continuous populations of Bornean agile gibbons. The designation of the Sabangau forest as a national park will hopefully address the problem of illegal logging and hunting in the region. Further studies should note any difference in gibbon density post protection.

Rapid Soil Stabilization of Soft Clay Soils for Contingency Airfields

DTIC Science & Technology

2006-12-01

quicklime or calcium carbide, could possibly crosslink the polymers of sodium or potassium polyacrylic acid together to form a harder material. Very...LiquiBlock 40K and 41K are both potassium salts of crosslinked polyacrylic acids/polyacrylamide copolymers in granular form that also gel in the presence...communication, 2006), soil could possibly be stabilized with calcium and super absorbent polymers, such as sodium or potassium polyacrylic acids. This

Atypical soil behavior during the 2011 Tohoku earthquake ( Mw = 9)

NASA Astrophysics Data System (ADS)

Pavlenko, Olga V.

2016-07-01

To understand physical mechanisms of generation of abnormally high peak ground acceleration (PGA; >1 g) during the Tohoku earthquake, models of nonlinear soil behavior in the strong motion were constructed for 27 KiK-net stations located in the near-fault zones to the south of FKSH17. The method of data processing used was developed by Pavlenko and Irikura, Pure Appl Geophys 160:2365-2379, 2003 and previously applied for studying soil behavior at vertical array sites during the 1995 Kobe (Mw = 6.8) and 2000 Tottori (Mw = 6.7) earthquakes. During the Tohoku earthquake, we did not observe a widespread nonlinearity of soft soils and reduction at the beginning of strong motion and recovery at the end of strong motion of shear moduli in soil layers, as usually observed during strong earthquakes. Manifestations of soil nonlinearity and reduction of shear moduli during strong motion were observed at sites located close to the source, in coastal areas. At remote sites, where abnormally high PGAs were recorded, shear moduli in soil layers increased and reached their maxima at the moments of the highest intensity of the strong motion, indicating soil hardening. Then, shear moduli reduced with decreasing the intensity of the strong motion. At soft-soil sites, the reduction of shear moduli was accompanied by a step-like decrease of the predominant frequencies of motion. Evidently, the observed soil hardening at the moments of the highest intensity of the strong motion contributed to the occurrence of abnormally high PGA, recorded during the Tohoku earthquake.

Freshwater Wetlands.

ERIC Educational Resources Information Center

Naturescope, 1986

1986-01-01

Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

Invitation to the Swamp: An Educational Insert

ERIC Educational Resources Information Center

Thomas, Bill

1976-01-01

In this third special educational supplement, the swamp is discussed. Included is information on where land and water meet to form the great incubator of wildlife, and on endangered species of wildlife, such as the red wolf, brown pelican, manatee, great white heron and woodstork. (BT)

Woody vegetation communities of tidal freshwater swamps in South Carolina, Georgia and Florida (US) with comparisons to similar systems in the US and South America

USGS Publications Warehouse

Duberstein, Jamie A.; Conner, William H.; Krauss, Ken W.

2014-01-01

Descriptions of most tidal freshwater swamps in the southeastern US fit within the communities described in this study. Because studies that make inferences between environmental drivers (e.g. salinity, hydroperiod, hurricanes) and specific community types are best applied to the same communities (but perhaps different river systems), this work provides a framework by which tidal freshwater forested wetlands can be accurately compared based on their tree communities. We suggest that, within the broad range of our inventories, the four communities described identify the primary associations that should be tracked within most tidal freshwater swamps of the US. However, we identify some river basins in the US that do not fit this construct. Diversity of major tree communities in tidal freshwater swamps outside the US is generally much lower (with the notable exception of Amazonian hardwood tidal várzea), as are basal area values.

A Project to Map and Monitor Baldcypress Forests in Coastal Louisiana, Using Landsat, MODIS, and ASTER Satellite Data

NASA Technical Reports Server (NTRS)

Spruce, Joseph; Sader, Steven; Smoot, James

2012-01-01

Cypress swamp forests of Louisiana offer many important ecological and economic benefits: wildlife habitat, forest products, storm buffers, water quality, and recreation. Such forests are also threatened by multiple factors: subsidence, salt water intrusion, sea level rise, persistent flooding, hydrologic modification, hurricanes, insect and nutria damage, timber harvesting, and land use conversion. Unfortunately, there are many information gaps regarding the type, location, extent, and condition of these forests. Better more up to date swamp forest mapping products are needed to aid coastal forest conservation and restoration work (e.g., through the Coastal Forest Conservation Initiative or CFCI). In response, a collaborative project was initiated to develop, test and demonstrate cypress swamp forest mapping products, using NASA supported Landsat, ASTER, and MODIS satellite data. Research Objectives are: Develop, test, and demonstrate use of Landsat and ASTER data for computing new cypress forest classification products and Landsat, ASTER, and MODIS satellite data for detecting and monitoring swamp forest change

Morphological adaptation with no mitochondrial DNA differentiation in the coastal plain swamp sparrow

USGS Publications Warehouse

Greenberg, R.; Cordero, P.J.; Droege, S.; Fleischer, R.C.

1998-01-01

We estimated genetic differentiation between morphologically distinct tidal marsh populations of Swamp Sparrows (Melospiza georgiana nigrescens) and the more widespread inland populations (M. g. georgiana and M. g. ericrypta). The tidal marsh populations are consistently grayer with more extensive black markings (particularly in the crown), and their bills are larger. These differences are variously shared with other species of salt marsh birds and small mammals. We analyzed mitochondrial DNA sequences (5′ end of control region, COII/t-lys/ATPase8, and ND2) of Swamp Sparrows and found low levels of genetic variation and no evidence of geographic structure. These results suggest a rapid and recent geographic expansion of Swamp Sparrows from restricted Pleistocene populations. Morphological differentiation has occurred without long-term genetic isolation, suggesting that selection on the divergent traits is intense. The grayer and more melanistic plumage is probably cryptic coloration for foraging on tidal mud, which tends to be grayish as a result of the formation of iron sulfides, rather than iron oxides, under anaerobic conditions.

The timing and cause of megafauna mass deaths at Lancefield Swamp, south-eastern Australia

NASA Astrophysics Data System (ADS)

Dortch, Joe; Cupper, Matt; Grün, Rainer; Harpley, Bernice; Lee, Kerrie; Field, Judith

2016-08-01

Lancefield Swamp, south-eastern Australia, was one of the earliest sites to provoke interest in Pleistocene faunal extinctions in Sahul (Pleistocene Australia-New Guinea). The systematic investigation of the deposit in the early 1970s identified megafaunal remains dominated by the 100-200 kg kangaroo Macropus giganteus titan. Associated radiocarbon ages indicated that the species was extant until c.30,000 BP, suggesting significant overlap with human settlement of Sahul. This evidence was inconsistent with contemporary models of rapid human-driven extinctions. Instead, researchers inferred ecological tethering of fauna at Lancefield Swamp due to intense drought precipitated localised mass deaths, consistent with Late Pleistocene climatic variability. Later investigations in another part of the swamp, the Mayne Site, remote to the initial investigations, concluded that mass flow disturbed this area, and Electron Spin Resonance (ESR) analyses on megafauna teeth returned wide-ranging ages. To clarify site formation processes and dating of Lancefield Swamp, we excavated new test-pits next to previous trenches in the Classic and Mayne Sites. We compared absolute chronologies for sediments and teeth, sedimentology, palaeo-topography, taphonomy, and macropod age at death across the swamp. Luminescence dating of sediments and ESR analysis of teeth returned ages between c.80,000 and 45,000 years ago. We found no archaeological remains in the bone beds, and evidence of carnivore activity and fluvial action, in the form of reactivated spring flow. The latter disturbed limited parts of the site and substantial areas of the bone beds remained intact. The faunal assemblage is dominated by megafaunal adult Macropus, consistent with mass die-offs due to severe drought. Such droughts appear to have recurred over millennia during the climatic variability of Marine Isotope Stages 4 and 3. These events began tens of millennia before the first appearance of Aboriginal people in Sahul and only the very youngest fossil deposits could be coeval with the earliest human arrivals. Therefore, anthropogenic causes cannot be implicated in most if not all of mass deaths at the site. Climatic and environmental changes were the main factors in site formation and megafauna deaths at Lancefield Swamp.

The effect of soil texture on the degradation of textiles associated with buried bodies.

PubMed

Lowe, A C; Beresford, D V; Carter, D O; Gaspari, F; O'Brien, R C; Stuart, B H; Forbes, S L

2013-09-10

There are many factors which affect the rate of decomposition in a grave site including; the depth of burial, climatic conditions, physical conditions of the soil (e.g. texture, pH, moisture), and method of burial (e.g. clothing, wrappings). Clothing is often studied as a factor that can slow the rate of soft tissue decomposition. In contrast, the effect of soft tissue decomposition on the rate of textile degradation is usually reported as anecdotal evidence rather than being studied under controlled conditions. The majority of studies in this area have focused on the degradation of textiles buried directly in soil. The purpose of this study was to investigate the effect of soil texture on the degradation and/or preservation of textile materials associated with buried bodies. The study involved the burial of clothed domestic pig carcasses and control clothing in contrasting soil textures (silty clay loam, fine sand and fine sandy loam) at three field sites in southern Ontario, Canada. Graves were exhumed after 2, 12 and 14 months burial to observe the degree of degradation for both natural and synthetic textiles. Recovered textile samples were chemically analyzed using infrared (IR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) to investigate the lipid decomposition by-products retained in the textiles. The findings of this study demonstrate that natural textile in contact with a buried decomposing body will be preserved for longer periods of time when compared to the same textile buried directly in soil and not in contact with a body. The soil texture did not visually impact the degree of degradation or preservation. Furthermore, the natural-synthetic textile blend was resistant to degradation, regardless of soil texture, contact with the body or time since deposition. Chemical analysis of the textiles using GC-MS correctly identified a lipid degradation profile consistent with the degree of soft tissue decomposition. Such information may be important for estimating time since deposition in instances where only grave goods and associated materials are recovered from a burial site. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

77 FR 37391 - Combined Notice of Filings #2

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-21

...: Bear Swamp Power Company LLC, Brookfield Energy Marketing Inc., Brookfield Energy Marketing LP... Power, LLC, Great Lakes Hydro America LLC, Hawks Nest Hydro LLC, Longview Fibre Paper and Packaging, Inc., Rumford Falls Hydro LLC. Description: Supplement to Notice of Non-Material Change in Status of Bear Swamp...

Emergy and Evaluating Ecosystem Services in a Sumatran Peat Swamp, Indonesia. Chapter 13

EPA Science Inventory

The purpose of this article is to document preliminary investigations into valuing peat swamp ecosystem function and services in Indonesia and to compare these values with the current development alternative, Acacia pulp wood plantation, using the emergy methodology. The Zamrud N...

77 FR 66737 - Final Flood Elevation Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-07

... +45 upstream of Cedar Swamp Road. Clapps Swamp Approximately 0.4 mile +51 Unincorporated Areas of.... 4104, and 44 CFR part 67. FEMA has developed criteria for floodplain management in floodprone areas in... Location Depth in feet above ground [caret] Elevation in meters (MSL)Modified Unincorporated Areas of...

In-situ evaluation of design parameters and procedures for cementitiously treated weak subgrades using cyclic plate load tests : project capsule.

DOT National Transportation Integrated Search

2013-06-01

Due to the soft nature of subsurface soils in southern Louisiana, roads often have to : be constructed on very weak subgrade soils with high in-situ moisture contents that : do not have the suffi cient strength/stiff ness to support the construction/...

Yeast communities in Sphagnum phyllosphere along the temperature-moisture ecocline in the boreal forest-swamp ecosystem and description of Candida sphagnicola sp. nov.

PubMed

Kachalkin, Aleksey V; Yurkov, Andrey M

2012-06-01

The effects of the temperature-moisture factors on the phylloplane yeast communities inhabiting Sphagnum mosses were studied along the transition from a boreal forest to a swamp biotope at the Central Forest State Biosphere Reserve (Tver region, Russia). We tested the hypothesis that microclimatic parameters affect yeast community composition and structure even on a rather small spatial scale. Using a conventional plating technique we isolated and identified by molecular methods a total of 15 species of yeasts. Total yeast counts and species richness values did not depend on environmental factors, although yeast community composition and structure did. On average, Sphagnum in the swamp biotope supported a more evenly structured yeast community. Relative abundance of ascomycetous yeasts was significantly higher on swamp moss. Rhodotorula mucilaginosa dominated in the spruce forest and Cryptococcus magnus was more abundant in the swamp. Our study confirmed the low occurrence of tremellaceous yeasts in the Sphagnum phyllosphere. Of the few isolated ascomycetous yeast and yeast-like species, some were differentiated from hitherto known species in physiological tests and phylogenetic analyses. We describe one of them as Candida sphagnicola and designate KBP Y-3887(T) (=CBS 11774(T) = VKPM Y-3566(T) = MUCL 53590(T)) as the type strain. The new species was registered in MycoBank under MB 563443.

Lower food chain community study: thermal effects and post-thermal recovery in the streams and swamps of the Savannah River Plant, November 1983-May 1984

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

Kondratieff, B.C.; Kondratieff, P.

1985-04-01

This report documents a study of lower food chain (autotroph and macroinvertebrate assemblage) response to, and recovery from, thermal stress in the streams and swamps of the Savannah River Plant (SRP). Data for the report were collected between November 1983 and May 1984. Elevated water temperature regimes in the thermal streams and swamps resulted in generally simplified lower food chain community structure. Thermally tolerant forms of both autotrophs (blue-green algae) and macroinvertebrates (oligochaetes, nematodes, snails and midges) were able to maintain populations in thermally stressed areas. The thermally tolerant taxa found in the perturbed streams and swamps often had highmore » densities and biomass. It would appear tht many of the macroinvertebrate species occurring in SRP streams and swamps evolved in habitats subject to great thermal variation, both diel and seasonal. Based on the results of this study, certain temperature ranges are associated with certain general effects on the lower food chain. In temperatures >40/sup 0/C most taxa are eliminated, from 30 to 40/sup 0/C a stressed community exists with a few tolerant taxa and from 25 to 30/sup 0/C an assemblage resembling a summer ambient community in structure and function exists, often with reduced species composition. 74 refs., 20 figs., 18 tabs. (ACR)« less

Seasonal and diel patterns of larval fish drift in a western South Carolina swamp

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

Kissick, L.A.; Paller, M.H.; Heuer, J.H.

1988-01-01

Fish larvae were collected weekly during 1986-1987 from the lower 3 km of Steel Creek (Barnwell County), a riverine swamp, to assess reproduction in this rarely studied habitat type. In 1987, larvae appeared in the following order and abundance (as a percentage of the total diural density): blackbanded darter Percina nigromaculatus (3%) and other darters Etheostoma spp. (32%); pirate perch Aphredoderus sayanus (NA); pygmy sunfish Elassoma spp. (7%); chubsuckers Erimyson spp. (13%); bluespotted sunfish Enneacanthus gloriosus (16%); bluegill Lepomis macrochirus (1%), redbreast sunfish L. auritus (<1%), brook silverside Labidesthes sicculus (6%) and ironcolor shiner Notropis chalybaeus (8%); warmouth L. gulosusmore » (8%); spotted sunfish L. punctatus (NA). Unidentified cyprinids (2%), centrarchids (2%) and miscellaneous species (3%) were collected throughout the study period. Monthly diel collections showed that drift densities of chubsuckers, cyprinids, Etheostoma spp., bluegill and pygmy sunfish increased 41 to 160X after sundown; pirate perch and spotted sunfish were collected only at night. Swamp densities peaked during 2000-0159 h (111.5 per 100m), whereas densities in the channel that drained the swamp into the Savannah River peaked during 0200-0759 h (38.7). The later peak in the channel was attributed to larvae that had drifted from the swamp and were essentially lost from the system. 4 figs., 1 tab.« less

Effect of redox conditions on bacterial and fungal biomass and carbon dioxide production in Louisiana coastal swamp forest sediment.

PubMed

Seo, Dong Cheol; DeLaune, Ronald D

2010-08-01

Fungal and bacterial carbon dioxide (CO2) production/emission was determined under a range of redox conditions in sediment from a Louisiana swamp forest used for wastewater treatment. Sediment was incubated in microcosms at 6 Eh levels (-200, -100, 0, +100, +250 and +400 mV) covering the anaerobic range found in wetland soil and sediment. Carbon dioxide production was determined by the substrate-induced respiration (SIR) inhibition method. Cycloheximide (C15H23NO4) was used as the fungal inhibitor and streptomycin (C21H39N7O12) as the bacterial inhibitor. Under moderately reducing conditions (Eh > +250 mV), fungi contributed more than bacteria to the CO2 production. Under highly reducing conditions (Eh < or = 0 mV), bacteria contributed more than fungi to the total CO2 production. The fungi/bacteria (F/B) ratios varied between 0.71-1.16 for microbial biomass C, and 0.54-0.94 for microbial biomass N. Under moderately reducing conditions (Eh > or = +100 mV), the F/B ratios for microbial biomass C and N were higher than that for highly reducing conditions (Eh < or = 0 mV). In moderately reducing conditions (Eh > or = +100 mV), the C/N microbial biomass ratio for fungi (C/N: 13.54-14.26) was slightly higher than for bacteria (C/N: 9.61-12.07). Under highly reducing redox conditions (Eh < or = 0 mV), the C/N microbial biomass ratio for fungi (C/N: 10.79-12.41) was higher than for bacteria (C/N: 8.21-9.14). For bacteria and fungi, the C/N microbial biomass ratios under moderately reducing conditions were higher than that in highly reducing conditions. Fungal CO2 production from swamp forest could be of greater ecological significance under moderately reducing sediment conditions contributing to the greenhouse effect (GHE) and the global warming potential (GWP). However, increases in coastal submergence associated with global sea level rise and resultant decrease in sediment redox potential from increased flooding would likely shift CO2 production to bacteria rather than fungi. 2010 Elsevier B.V. All rights reserved.

Analysis of physical parameters related with water infiltration in tropical soils located in edges forest in urban areas

NASA Astrophysics Data System (ADS)

Márcia Longo, Regina; Cunha, Jessica C. M.; Lammoglia, Rafaella; Mendes, Deborah R.; Mungilioli, Sarah S.; Damame, Desiree B.; Demamboro, Antônio C.; Bettine, Sueli C.; Ribeiro, Admilson I.; Fengler, Felipe H.

2015-04-01

A very important factor for water infiltration into the soil in urban forest systems and suffering constant anthropogenic pressures is the analysis of soil compaction where these forests are or will be established. In this context, this work aimed to promote studies on physical parameters related to distribution of pores, compaction and soil biological activity in forest remnants border areas located in urban watersheds in Campinas / SP - Brazil. The Forest of Santa Genebra (22°49'45 "S and 47°06'33" W) has an average altitude of 680m and tropical climate of altitude, has an area of 251 ha and a nine kilometer perimeter. It constitutes 85% of Semideciduos forests and 15% swamp forest. Due to its location close to urban centers, roads and agricultural areas under direct influence of the anthropic means. For the present study analyzes were performed: particle size, soil density, porosity, matters organic, of biopores, and root distribution (primary, secondary and tertiary) and seedlings in 40 points on the perimeter of the forest equidistant 200m remaining edge. The analysis of the results allowed us to observe that areas suffer direct influence of human activities surrounding. With the results set correlations between the different parameters in order to allow a better understanding of the dynamics of water infiltration into the soil under these conditions and the quantity of tertiary roots, biopores and soil density were the best indicator of environmental quality as suffer direct influence of the surrounding areas, especially those near the most urbanized regions. In general, it can be observed that human activities such as deforestation and vehicle traffic, animals and people, promoted soil compaction and consequent changes in water infiltration into the soil in areas of edges of this remnant of these consequences affect direct numerous parameters that directly influence the dynamics of an ecosystem restoration that is now significantly affected by the occupation of their surroundings.

Nutrients and biomass spatial patterns in alpine tundra ecosystem on Changbai Mountains, Northeast China.

PubMed

Wu, Gang; Jiang, Ping; Wei, Jing; Shao, Hongbo

2007-11-15

Biomass and nutrients were investigated in 2003, 2004 and 2005 growing seasons by using a chronosequence of five vegetation types in alpine tundra on Changbai Mountains. The objective of this study was to test whether nutrients at biointerfaces were significant differences among five vegetation types. The biomass and elevation are highly related (biomass=-237.3ln(elevation)+494.36; R(2)=0.8092; p<0.05). There were no significant differences in phosphorus (P) and sulphur (S) concentrations of roots, stems and leaves among five vegetation types while there are significant differences in nitrogen (N) and P stocks of roots, stems and leaves and in S stock of stems and leaves among typical alpine tundra vegetation (TA), meadow alpine tundra vegetation (MA), and swamp alpine tundra vegetation (SA) (p<0.05). Vegetation nutrients stock is averagely 72.46kg hm(-2), and N, P, S stocks are 48.55, 10.33 and 13.61kg hm(-2), respectively. Soil N and S concentrations in MA are significantly higher than those in other four soil types. P is higher in SA (p<0.05). Soil nutrients stock (0-20cm) is averagely 39.59t hm(-2), and N, P, S stocks are 23.74, 5.86 and 9.99t hm(-2), respectively.

A new heterolobosean amoeba Solumitrus palustris n. g., n. sp. isolated from freshwater marsh soil.

PubMed

Anderson, O Roger; Wang, Wen; Faucher, Sebastien P; Bi, Keran; Shuman, Howard A

2011-01-01

During the course of research on the bacterial feeding behavior and resistance of amoebae to virulent pathogens, we isolated a new strain of amoeba from organic rich soil at the margin of freshwater swamp in the northeastern United States. Light microscopic morphology is characteristically heterolobosean, resembling vahlkampfiids, including a broadened, limax shape, and eruptive locomotion, but occasionally becoming more contracted and less elongated with lateral or anterior bulges and somewhat branching sparse, uroidal filaments. Electron microscopic evidence, including mitochondria with flattened cristae surrounded by rough endoplasmic reticulum, further indicates a heterolobosean affinity. The solitary nucleus contains a centrally located nucleolus. Cysts are rounded with occasionally an eccentrically located nucleus. The cyst walls are relatively thin, becoming crenated, and loosely enclosing the cyst when mature. Molecular genetic evidence places this isolate among the Heterolobosea, branching most closely in a clade including Allovahlkampfia spelaea and previously isolated, un-named strains of soil amoebae. Based on differentiated features, including morphology of the uroid, cyst wall structure, and molecular genetic evidence that distinguish it from A. spelaea, a new genus and species, Solumitrus palustris, is proposed for this new heterolobosean. © 2010 The Author(s). Journal of Eukaryotic Microbiology © 2010 International Society of Protistologists.

Guidebook of the Western United States: Part F - The Southern Pacific lines, New Orleans to Los Angeles

USGS Publications Warehouse

Darton, Nelson Horatio

1933-01-01

The Southern Pacific Railroad from New Orleans to Los Angeles, a distance of about 2,000 miles, passes through a region exhibiting a great variety of geographic and industrial conditions. The climate, especially the amount of precipitation, is the most influential factor in causing this variety. The low Coastal Plain of southern Louisiana and eastern Texas, with ample rainfall and thick rich soils, is a province distinct in configuration, human occupations, and products. There are extensive swamps, prairies, and wooded areas, but a large part of the land is under cultivation, with sugarcane, cotton, and rice as the principal crops. The streams are wide and slow, the winter climate is mild, and the summer heat is tempered by breezes from the Gulf of Mexico. Flourishing towns occur at short intervals, and some of them are growing rapidly. The entire region is underlain by a great thickness of sand and clay of alluvial origin. In central-eastern Texas the Coastal Plain is higher, the soil conditions are materially different, the streams run more swiftly, swamps become rare, and although much land is under cultivation, many areas are either in pasture or not cleared. The vegetation changes with change of soil and increase of altitude, and the crops are more diversified than in the lower parts of the Coastal Plain. The region is underlain by sandstone, shale, and other formations, which rise toward the west, cropping out in regular succession as they are crossed from east to west. Some of these formations are hard enough to make ridges and knobs, and there is general terracing at various levels. Parts of the highest lands are remnants of an old plain of former wide extent. Beyond San Antonio the traveler observes several changes in the general aspect of the country, for although the Coastal Plain extends west to Del Rio, there is both a gradual increase in elevation to about 1,000 feet and a marked diminution of rainfall to the west, which greatly affect landscape and industries. Cacti become larger and more abundant, and many special trees and plants are prevalent, notably the mesquite; forests diminish in density, and far to the west trees occur only in the bottom lands. Agriculture here depends largely on irrigation, and the raising of cattle, sheep, and goats is the dominant industry. The principal underlying rocks are shale, soft sandstone, and chalk, which do not make strong relief but produce hills and ridges of moderate height separated by wide valleys, which along the larger streams are bordered by bottom lands. Northwest of San Antonio the Coastal Plain gives place rather abruptly to the Edwards Plateau, owing to the rapid rise of hard limestones; from San Antonio to Del Rio this feature lies north of the railroad but is visible at many places. For many miles west from Del Rio the railroad is on the plateau, which is floored by hard limestone and deeply trenched by the drainageways, notably by the canyons of the Devils River, the Rio Grande, and the Pecos River. In this district, where semiarid conditions prevail, vegetation is sparse and trees are mostly confined to valley bottoms except where the limestone supports a growth of juniper or live oak. The soil is thin, but it sustains grass and shrubs which afford good pasturage for many goats, sheep, and cattle. Owing to the gradual general rise of the strata to the west the land increases in elevation, and much of the plateau in south-central Texas is 2,000 feet above sea level in its eastern part and 3,000 feet in its western part. Near Sanderson this rise develops into the great dome of the Marathon uplift. The central part of this uplift is truncated, revealing a large area of closely folded Paleozoic rocks, making sharp ridges of the Appalachian type. The Edwards Plateau ends on the east side of this uplift. To the west is the Davis Mountain region, a wide province of volcanic rocks, characterized by rugged peaks and irregularly disposed ridges in great va

75 FR 8107 - Bond Swamp National Wildlife Refuge, Bibb and Twiggs Counties, GA

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... impact. SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce the availability of our final comprehensive Conservation Plan (CCP) and finding of no significant impact (FONSI) for the environmental..., including upland mixed pine/hardwood, bottomland hardwood, and tupelo gum swamp forests. Creeks, beaver...

Great Dismal Swamp National Wildlife Refuge Interagency Assistance Group : transportation observations, considerations and recommendations

DOT National Transportation Integrated Search

2014-07-01

In March 2014, U.S. FWS hosted a Transportation Assistance Group at the Great Dismal Swamp in Virginia. The purpose of the meeting was to identify transportation issues impacting the refuge, ways to improve access to and within the refuge, as well as...

Establishment of Swamp Tupelo Seedlings After Regeneration Cuts

Treesearch

Dean S. DeBell; J. Dennis Auld

1971-01-01

Environmental factors influencing natural regeneration of swamp tupelo were examined in a study involving five harvest treatments replicated in 3 successive years. Initial seedling establishment was related to seed production, but other factors probably are more limiting in most years. Abundance of established seedlings differed significantly with harvest cuttings,...

Fire management and research for biodiversity in the Green Swamp

Treesearch

Margit A. Bucher; Maura E. High

2002-01-01

The Nature Conservancy has conducted prescribed burns for two decades in North Carolina's Green Swamp to enhance and maintain species biodiversity in the longleaf pine (Pinus palustris) savannas and ecotones. The surrounding pocosins, however, have been left alone. Increasingly, dense shrub growth in the pocosin suppresses herbaceous species and...

Cola soft drinks for evaluating the bioaccessibility of uranium in contaminated mine soils.

PubMed

Lottermoser, Bernd G; Schnug, Ewald; Haneklaus, Silvia

2011-08-15

There is a rising need for scientifically sound and quantitative as well as simple, rapid, cheap and readily available soil testing procedures. The purpose of this study was to explore selected soft drinks (Coca-Cola Classic®, Diet Coke®, Coke Zero®) as indicators of bioaccessible uranium and other trace elements (As, Ce, Cu, La, Mn, Ni, Pb, Th, Y, Zn) in contaminated soils of the Mary Kathleen uranium mine site, Australia. Data of single extraction tests using Coca-Cola Classic®, Diet Coke® and Coke Zero® demonstrate that extractable arsenic, copper, lanthanum, manganese, nickel, yttrium and zinc concentrations correlate significantly with DTPA- and CaCl₂-extractable metals. Moreover, the correlation between DTPA-extractable uranium and that extracted using Coca-Cola Classic® is close to unity (+0.98), with reduced correlations for Diet Coke® (+0.66) and Coke Zero® (+0.55). Also, Coca-Cola Classic® extracts uranium concentrations near identical to DTPA, whereas distinctly higher uranium fractions were extracted using Diet Coke® and Coke Zero®. Results of this study demonstrate that the use of Coca-Cola Classic® in single extraction tests provided an excellent indication of bioaccessible uranium in the analysed soils and of uranium uptake into leaves and stems of the Sodom apple (Calotropis procera). Moreover, the unconventional reagent is superior in terms of availability, costs, preparation and disposal compared to traditional chemicals. Contaminated site assessments and rehabilitation of uranium mine sites require a solid understanding of the chemical speciation of environmentally significant elements for estimating their translocation in soils and plant uptake. Therefore, Cola soft drinks have potential applications in single extraction tests of uranium contaminated soils and may be used for environmental impact assessments of uranium mine sites, nuclear fuel processing plants and waste storage and disposal facilities. Copyright © 2011 Elsevier B.V. All rights reserved.

Interdependence of peat and vegetation in a tropical peat swamp forest.

PubMed Central

Page, S E; Rieley, J O; Shotyk, W; Weiss, D

1999-01-01

The visual uniformity of tropical peat swamp forest masks the considerable variation in forest structure that has evolved in response to differences and changes in peat characteristics over many millennia. Details are presented of forest structure and tree composition of the principal peat swamp forest types in the upper catchment of Sungai Sebangau, Central Kalimantan, Indonesia, in relation to thickness and hydrology of the peat. Consideration is given to data on peat geochemistry and age of peat that provide evidence of the ombrotrophic nature of this vast peatland and its mode of formation. The future sustainability of this ecosystem is predicted from information available on climate change and human impact in this region. PMID:11605630

Monitoring of Deep Foundation Pit Support and Construction Process in Soft Soil Area of Pearl River Delta

NASA Astrophysics Data System (ADS)

Weiyi, Xie; Pengcheng

2018-03-01

The deep foundation pit supporting technology in the soft soil area of the Pearl River Delta is more complicated, and many factors influence and restrict it. In this project as an example, according to the geological conditions and the surrounding circumstances, the main foundation using bored piles and pre-stressed anchor cable supporting structure + five axis cement mixing pile curtain supporting form; partial use of double row piles supporting structure + five axis cement mixing pile curtain support type. Through the monitoring results of construction show that the foundation pit, the indicators of environmental changes are in the design range, the supporting scheme of deep foundation pit technology is feasible and reliable.

Association study of resistance to soil-borne wheat mosaic virus (SBWMV) in U.S. winter wheat

USDA-ARS?s Scientific Manuscript database

Soil-borne wheat mosaic virus (SBWMV) is one of the most important winter wheat pathogens worldwide. To identify genes for resistance to the virus in U.S. winter wheat, association study was conducted using a selected panel of 205 elite experimental lines and cultivars from U.S. hard and soft winter...

Differential recovery of a deepwater swamp forest across a gradient of disturbance intensity

Treesearch

Diane De Steven; Rebecca R. Sharitz

1997-01-01

On the Savannah River Site, South Carolina, USA, large areas of floodplain swamp forest of baldcypress (Taxodium distichum) and water tupelo (Nyssa aquatica) were destroyed by the cumulative impacts of cooling-water discharges over a 35-year period of nuclear reactor operations. In one floodplain area, four years after thermal...

Patterns of Seasonal Abundance and Social Segregation in Inland and Coastal Plain Swamp Sparrows in a Delaware Tidal Marsh

EPA Science Inventory

The Coastal Plain Swamp Sparrow (Melospiza georgiana nigrescens, CPSS) breeds in the coastal brackish marshes of the North American Mid-Atlantic States. During the non-breeding season, coastal brackish marshes are occupied by both this subspecies and two far more widespread inte...

Vascular flora of Douglas Point, Charles County, Maryland. Final report

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

Miles, K.J.

1980-01-01

The environment and vascular flora of a 561 hectare (1400 acre) site on the western shore of the Chesapeake Bay in Maryland are described. Six habitats are represented: mixed hardwood forest, pine forest, open field, freshwater marsh, shrub swamp, and tree swamp. An annotated list of 531 species is included.

Learning To Love the Swamp: Reshaping Education for Public Service.

ERIC Educational Resources Information Center

Schall, Ellen

1996-01-01

The world of public service is compared to a swamp in which important, complex, and messy problems are addressed, and it is argued that graduate and professional education must be reshaped to produce leaders who can make sense of current challenges. Education that is more experiential, behavioral, interactive, and collectively oriented is…

Potential roles of fish, birds, and water in swamp privet (Forestiera acuminata) seed dispersal

Treesearch

Susan B. Adams; Paul B. Hamel; Kristina Connor; Bryce Burke; Emile S. Gardiner; David Wise

2007-01-01

Forestiera acuminata (swamp privet) is a common wetland shrub/small tree native to the southeastern United States. We examined several possible dispersal avenues for the plant. We tested germination of seeds exposed to various treatments, including passage through Ictalurus punctatus (Channel Catfi sh) guts, and conducted other...

Composition and species diversity of pine-wiregrass savannas of the Green Swamp, North Carolina

Treesearch

Joan Walker; Robert K. Peet

1983-01-01

Fire-maintained, species-rich pines wiregrass savannas in the Green Swamp, North Carolina were sampled over their natural range of environmental conditions and fire frequencies. Species composition, species richness, diversity (Exp H', I/ C), and aboveground production were documented and fertilization experiments conducted to assess possible mechanisms for the...

Characterization of a double WAP domain-containing protein from the red swamp crayfish Procambarus clarkii

USDA-ARS?s Scientific Manuscript database

Crustaceans express multiple whey acidic protein (WAP) domain containing proteins which are components of host immunity. In the present study, a new double WAP domain containing protein was identified from red swamp crayfish Procambarus clarkii, designated Pc-DWD. The ORF is 387 bp, encoding 128 ami...

Producer farmer’s sovereignty in dry land and swamps areas

NASA Astrophysics Data System (ADS)

Suhaeti, RN; Wahyuni, S.

2018-01-01

Farmers could perform their farming if they have sovereignty on their farming production inputs and marketing. Suboptimal land, such as dry land and swamps areas have good prospect if applying appropriate technologies. A research in 2015, on status of farmers’ sovereignty, had been conducted in Piani and North Candi Laras Subdistricts, Tapin District, South Borneo Province, representing swamp land and dry land respectively. Data and information were obtained through interviewing related agencies at provincial and district levels and 30 units of farmer’s households. The primary and secondary data were analyzed descriptively. The research results showed that farmers in swamps and dry land were categorized as large farmers and had sovereignty over the land and production. Water shortage and excessive in both land types could be overcome by giving access on appropriate technology such as programs making farmers improve their farming techniques and providing levees. In addition, land certification program, farming expansion and constructing new irrigated lowland were also some efforts to improve farmers’ sovereignty. It was crucial to identify and improve farmer’s sovereignty indicators through research in larger sites and samples.

Panama City and Canal

NASA Image and Video Library

1994-09-30

STS068-237-099 (30 September-11 October 1994) --- This 70mm frame shows the Panama Canal (center, between the two dark green belts) the main ship way to travel from the Atlantic to the Pacific Ocean. Also seen is a great deal of detail in Panama City (left center, on the Pacific Ocean coastline). Geologists studying the photography returned by Shuttle astronauts feel this picture is the best ever of the city. Agricultural fields can be seen on the east side of Panama City and on both sides of the Pan American Highway (the straight thin line extending to the left). Sedimentation in the Chepo River (upper left) is thought to be due to eroded soil from the agricultural lands near the sea. This river is surrounded by swamps lying along the Pacific coastline.

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

Nelson, E.A.; Rogers, V.A.

Swamp tupelo seedlings were planted in four areas which experienced previous tree mortality at the seeplines of the F- and H-Area Seepage Basins. The sites represented a range in severity of impact and stage of recovery. Seedlings were planted in February of 1994 and followed through the first growing season in the field. Survival on all sites through the first growing season was excellent, with greater than 92% of the seedlings still alive. Most seedlings appeared healthy with few external signs of stress. The performance of the seedlings will be followed in subsequent years to determine the physical state ofmore » the soil environment on seedling growth. Hopefully, the results will indicate that artificial reforestation can begin on similarly impacted sites prior to the beginning of natural revegetation of the site.« less

Peat deposits of North Carolina: Bulletin 88

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

Ingram, R.L.

1987-01-01

Fuel-grade peat is an accumulation of partially decomposed plant material that has less than 25% non-combustible material (ash). In eastern North Carolina peat has formed in the past 10,000 years in swamps or pocosins (coastal swamps), Carolina bays, and river floodplains. Most of the peat is found at the surface with no over-burden and usually ranges in thickness from 1 to 15 ft with an average of 4-1/2 ft. The mean ash content of the fuel-grade peats is about 7.4%, but ash contents of less than 5% are common in most peat deposits. Heating values average 10,100 Btu/lb on amore » moisture-free basis. Fuel-grade peat deposits cover about 677,000 acres (1060 sq mi) in coastal North Carolina with total resources of about 500 million tons of moisture-free peat. Of this total, about 284,000 acres (444 sq mi) with 319 million tons are underlain by peat greater than 4 ft thick. Peat resources are concentrated in the pocosins or coastal swamps of northeastern North Carolina with the Albemarle-Pamlico peninsula having 55% of the resources and the Dismal Swamp, 11%. The remaining coastal swamp deposits are small but significant. Although 96 Carolina bays have peat, only 46 have peat greater than 4 ft thick; and only one has more than 1 million tons of peat. None of the river floodplain peats located were very large, continuous, or of high quality. 75 refs.« less

Net ecosystem CO2 exchange of a primary tropical peat swamp forest in Sarawak, Malaysia

NASA Astrophysics Data System (ADS)

Tang Che Ing, A.; Stoy, P. C.; Melling, L.

2014-12-01

Tropical peat swamp forests are widely recognized as one of the world's most efficient ecosystems for the sequestration and storage of carbon through both their aboveground biomass and underlying thick deposits of peat. As the peat characteristics exhibit high spatial and temporal variability as well as the structural and functional complexity of forests, tropical peat ecosystems can act naturally as both carbon sinks and sources over their life cycles. Nonetheless, few reports of studies on the ecosystem-scale CO2 exchange of tropical peat swamp forests are available to-date and their present roles in the global carbon cycle remain uncertain. To quantify CO2 exchange and unravel the prevailing factors and potential underlying mechanism regulating net CO2 fluxes, an eddy covariance tower was erected in a tropical peat swamp forest in Sarawak, Malaysia. We observed that the diurnal and seasonal patterns of net ecosystem CO2 exchange (NEE) and its components (gross primary productivity (GPP) and ecosystem respiration (RE)) varied between seasons and years. Rates of NEE declined in the wet season relative to the dry season. Conversely, both the gross primary productivity (GPP) and ecosystem respiration (RE) were found to be higher during the wet season than the dry season, in which GPP was strongly negatively correlated with NEE. The average annual NEE was 385 ± 74 g C m-2 yr-1, indicating the primary peat swamp forest functioned as net source of CO2 to the atmosphere over the observation period.

Distribution and accumulation of polybrominated diphenyl ethers (PBDEs) in Hong Kong mangrove sediments.

PubMed

Zhu, Haowen; Wang, Ying; Wang, Xiaowei; Luan, Tiangang; Tam, Nora F Y

2014-01-15

Polybrominated diphenyl ethers (PBDEs) have been used extensively as brominated flame retardants in various polymers, and have become serious environmental contaminants, particularly in coastal sediments. Mangrove wetlands are important coastal ecosystems in tropical and subtropical regions, and mangrove sediments are often the pollutant sinks due to their close proximity with human activities. In Hong Kong, sediment samples collected from five mangrove swamps were found to be contaminated with PBDEs and the eight measured BDE congeners, including BDE-28, -47, -99, -100, -153, -154, -183 and -209 were detected in all mangrove sediments, indicating that these pollutants were widespread in Hong Kong mangrove wetlands. Among the five swamps, relatively high concentrations of PBDEs were recorded in Mai Po mangrove swamp in the northwestern Hong Kong, which is part of the RAMSAR site but is severely influenced by the pollution from the Pearl River Delta. The depth profile of PBDEs in sediment cores collected from Mai Po also showed the inputs of PBDEs in this mangrove swamp increased year by year. In all sediments, the concentrations of BDE-209 were 1-2 orders of magnitude higher than the other congeners in the same sediment. The concentrations of BDE-209 and ∑PBDEs (defined as the sum of seven targeted BDE congeners except BDE-209) ranged from 1.53 to 75.9 ng g(-1) and from 0.57 to 14.4 ng g(-1), respectively. Among the targeted BDE congeners except BDE-209, slightly different composition was recorded among samples collected from different locations, with BDE-153 and -183 being the pre-dominated congeners. In all mangrove swamps, except Tai O in the southwest of Hong Kong, ∑PBDEs concentrations showed a common trend of landward>seaward>mudflat. The concentrations of ∑PBDEs were significantly correlated with total organic matter (TOM) content in sediments but not with the sediment particle sizes in each mangrove swamp. © 2013.

Spatial differences in hydrologic characteristics and water chemistry of a temperate coastal plain peatland: The Great Dismal Swamp, USA

USGS Publications Warehouse

Speiran, Gary K.; Wurster, Frederick C.

2016-01-01

Spatial differences in hydrologic processes and geochemistry across forested peatlands control the response of the wetland-community species and resiliency to natural and anthropogenic disturbances. Knowing these controls is essential to effectively managing peatlands as resilient wetland habitats. The Great Dismal Swamp is a 45,325 hectare peatland in the Atlantic Coastal Plain of Virginia and North Carolina, USA, managed by the U.S. Fish and Wildlife Service. The existing forest-species distribution is a product of timber harvesting, hydrologic alteration by canal and road construction, and wildfires. Since 2009, studies of hydrologic and geochemical controls have expanded knowledge of groundwater flow paths, water chemistry, response to precipitation events, and characteristics of the peat. Dominant hydrologic and geochemical controls include (1) the gradual slope in land surface, (2) vertical differences in the hydraulic characteristics of the peat, (3) the proximity of lateral groundwater and small stream inflows from uplands, (4) the presence of an extensive canal and road network, and (5) small, adjustable-height dams on the canals. Although upland sources provide some surface water and lateral groundwater inflow to western parts of the swamp, direct groundwater recharge by precipitation is the major source of water throughout the swamp and the only source in many areas. Additionally, the proximity and type of upland water sources affect water levels and nutrient concentrations in canal water and groundwater. Where streams are a dominant upland source, variations in groundwater levels and nutrient concentrations are greater than where recharge by precipitation is the primary water source. Where upland groundwater is a dominant source, water levels are more stable. Because the species distribution of forest communities in the Swamp is strongly influenced by these controls, swamp managers are beginning to incorporate this knowledge into forest, water, and fire management plans.

Warming effects on permafrost ecosystem carbon fluxes associated with plant nutrients.

PubMed

Li, Fei; Peng, Yunfeng; Natali, Susan M; Chen, Kelong; Han, Tianfeng; Yang, Guibiao; Ding, Jinzhi; Zhang, Dianye; Wang, Guanqin; Wang, Jun; Yu, Jianchun; Liu, Futing; Yang, Yuanhe

2017-11-01

Large uncertainties exist in carbon (C)-climate feedback in permafrost regions, partly due to an insufficient understanding of warming effects on nutrient availabilities and their subsequent impacts on vegetation C sequestration. Although a warming climate may promote a substantial release of soil C to the atmosphere, a warming-induced increase in soil nutrient availability may enhance plant productivity, thus offsetting C loss from microbial respiration. Here, we present evidence that the positive temperature effect on carbon dioxide (CO 2 ) fluxes may be weakened by reduced plant nitrogen (N) and phosphorous (P) concentrations in a Tibetan permafrost ecosystem. Although experimental warming initially enhanced ecosystem CO 2 uptake, the increased rate disappeared after the period of peak plant growth during the early growing season, even though soil moisture was not a limiting factor in this swamp meadow ecosystem. We observed that warming did not significantly affect soil extractable N or P during the period of peak growth, but decreased both N and P concentrations in the leaves of dominant plant species, likely caused by accelerated plant senescence in the warmed plots. The attenuated warming effect on CO 2 assimilation during the late growing season was associated with lowered leaf N and P concentrations. These findings suggest that warming-mediated nutrient changes may not always benefit ecosystem C uptake in permafrost regions, making our ability to predict the C balance in these warming-sensitive ecosystems more challenging than previously thought. © 2017 by the Ecological Society of America.

Concentration and transportation of heavy metals in vegetables and risk assessment of human exposure to bioaccessible heavy metals in soil near a waste-incinerator site, South China.

PubMed

Li, Ning; Kang, Yuan; Pan, Weijian; Zeng, Lixuan; Zhang, Qiuyun; Luo, Jiwen

2015-07-15

There is limited study focusing on the bioaccumulation of heavy metals in vegetables and human exposure to bioaccessible heavy metals in soil. In the present study, heavy metal concentrations (Cr, Ni, Cu, Pb and Cd) were measured in five types of vegetables, soil, root, and settled air particle samples from two sites (at a domestic waste incinerator and at 20km away from the incinerator) in Guangzhou, South China. Heavy metal concentrations in soil were greater than those in aerial parts of vegetables and roots, which indicated that vegetables bioaccumulated low amount of heavy metals from soil. The similar pattern of heavy metal (Cr, Cd) was found in the settled air particle samples and aerial parts of vegetables from two sites, which may suggest that foliar uptake may be an important pathway of heavy metal from the environment to vegetables. The highest levels of heavy metals were found in leaf lettuce (125.52μg/g, dry weight) and bitter lettuce (71.2μg/g) for sites A and B, respectively, followed by bitter lettuce and leaf lettuce for sites A and B, respectively. Swamp morning glory accumulated the lowest amount of heavy metals (81.02μg/g for site A and 53.2μg/g for site B) at both sites. The bioaccessibility of heavy metals in soil ranged from Cr (2%) to Cu (71.78%). Risk assessment showed that Cd and Pb in soil samples resulted in the highest non-cancer risk and Cd would result in unacceptable cancer risk for children and risk. The non-dietary intake of soil was the most important exposure pathway, when the bioaccessibility of heavy metals was taken into account. Copyright © 2015 Elsevier B.V. All rights reserved.

Distribution of artificial gamma-ray emitting radionuclide activity concentration in the top soil in the vicinity of the Ignalina Nuclear Power Plant and other regions in Lithuania.

PubMed

Lukšienė, Benedikta; Marčiulionienė, Danutė; Rožkov, Andrej; Gudelis, Arūnas; Holm, Elis; Galvonaitė, Audronė

2012-11-15

The impact of the operating Ignalina Nuclear Power Plant (INPP) on the contamination of top soil layer with artificial radionuclides has been studied. Results of the investigation of artificial gamma-ray emitting radionuclide distribution in soil in the vicinity of the INPP and distant regions in Lithuania in 1996-2008 (INPP operational period) show that nowadays (137)Cs remains the most important artificial gamma-ray emitting radionuclide in the upper soil layer. Mean (137)Cs activity concentrations in the top soil layer in the vicinity of the INPP were found to be significantly lower compared to those in remote regions of Varėna and Plungė (~300 km from INPP). In 1996 and 1998 mean (137)Cs activity concentrations were in the range of 28-45 Bq/kg in the nearest vicinity to the INPP, 103 Bq/kg in Varėna and 340 Bq/kg in Plungė region. (137)Cs activity concentrations were 5-20 times lower in meadow soil (4-14 Bq/kg) compared to swamp and forest soil. (60)Co, the INPP origin radionuclide, was detected in samples only in 1996 and 2000, and the activity concentration of (60)Co was found to be in the range from 0.4 to 7.0 Bq/kg at the sampling ground nearest to the INPP. Average annual activity concentrations of the INPP origin (137)Cs and (60)Co in the air and depositions in the INPP region were modeled using Pasquill-Gifford equations. The modeling results of (137)Cs and (60)Co depositional load in the INPP vicinity agree with the experimentally obtained values. Our results provide the evidence that the operation of INPP did not cause any significant contamination in soil surface. Copyright © 2012 Elsevier B.V. All rights reserved.

Isolation and characterization of EG-like cells from Chinese swamp buffalo (Bubalus bubalis).

PubMed

Huang, Ben; Xie, Ti-San; Shi, De-Shun; Li, Tong; Wang, Xiao-Li; Mo, Yi; Wang, Zhi-Qiang; Li, Meng-Mei

2007-10-01

There have been few studies done on the isolation and characterization of Chinese swamp buffalo embryonic germ cells (EG cells). Here, we first report on EG-like cells isolated from Chinese swamp buffalo fetuses. The results showed the cells grew in large, multilayered colonies, which were densely packed with an obvious border resembling mouse embryonic stem cells (ES cells) and EG cells. The buffalo EG-like cells expressed AP, SSEA-1, SSEA-3, SSEA-4 and OCT-4. By RT-PCR, we found that undifferentiated swamp buffalo EG-like cells expressed the OCT-4, NANOG, SOX2, FOXD3, GP130, STAT3, and HEB gene mRNA, but not Fgf4. When these cells were cultured for more than 2weeks without passage, they could differentiate into several types of cells including fibroblast-like, neuron-like, smooth muscle-like, and epithelial-like cells. Some cells formed simple embryoid bodies (EBs) and cystic EBs by suspension culture. By RT-PCR, we found cystic EBs expressed FOXD3, GP130, STAT3 and HEB gene mRNA, but not OCT-4, NANOG, and SOX2 gene mRNA, which could be detected in undifferentiated buffalo EG-like cells. At the same time, the expression of KERATIN-14 (Endoderm), GATA4, ACTA2 (Mesoderm) and TUBB3 (Ectoderm) gene mRNA were also detected in cystic EBs. The results suggested that these cells were capable of forming three germ layers in in vitro differentiation. The expression of OCT-4, NANOG and SOX2 might be essential for Chinese swamp buffalo EG-like cells in a pluripotent state. During the isolation and culture of Chinese swamp buffalo EG-like cells, we found the fetuses that were at 30-80days post-coitus were more efficient than others; and the mechanical method was better than trypsin digestion. The maximal passage of the mechanical method was eight, but the trypsin digestion was just three passages. So it seemed like that the buffalo EG-like cells were sensitive to trypsin. In summary, we were the first to isolate and characterize Chinese swamp buffalo EG-like cells that had morphology and characterization similar to those of established EG/EG-like cells in mouse and human.

Research on filling scheme and deformation properties of wide subgrade of foamed lightweight soil on soft ground

NASA Astrophysics Data System (ADS)

Zhang, Faru; Yang, Deguang; Zhang, Liujun

2018-01-01

The wide subgrade on soft soil ground has the significantly different transverse settlement curve characteristics and the lacation of the maximum asymmetrical transverse settlement compared with ordinary subgrade. Especially when the subgrade filled with materials of different densities, the synergism deformation of ground-subgrade-pavement and the pavement structure stress become more complex. Combining with the engineering example, the settlement deformation characteristics of wide subgrade adopting the different filling scheme and the stress distribution of pavement structure are analyzed. Results show that the settlement curve of wide subgrade has a shape of flat middle with steep sides, and the maximum transverse asymmetrical settlement locates in close to the shoulder position. The maximum stress within the pavement structure is also in close to the shoulder position. Regarding the wide subgrade composed of main road and relief road, the post-construction settlement can be greatly reduced when both roads are filled with foamed lightweight soil.

Research on dynamic creep strain and settlement prediction under the subway vibration loading.

PubMed

Luo, Junhui; Miao, Linchang

2016-01-01

This research aims to explore the dynamic characteristics and settlement prediction of soft soil. Accordingly, the dynamic shear modulus formula considering the vibration frequency was utilized and the dynamic triaxial test conducted to verify the validity of the formula. Subsequently, the formula was applied to the dynamic creep strain function, with the factors influencing the improved dynamic creep strain curve of soft soil being analyzed. Meanwhile, the variation law of dynamic stress with sampling depth was obtained through the finite element simulation of subway foundation. Furthermore, the improved dynamic creep strain curve of soil layer was determined based on the dynamic stress. Thereafter, it could to estimate the long-term settlement under subway vibration loading by norms. The results revealed that the dynamic shear modulus formula is straightforward and practical in terms of its application to the vibration frequency. The values predicted using the improved dynamic creep strain formula closed to the experimental values, whilst the estimating settlement closed to the measured values obtained in the field test.

The response of swamp harebell (Campanula californica) to timber harvest: a case study

Treesearch

Brad Valentine; Tracy Nelson; Clare Golec; Tony LaBanca; Stacey Martinelli

2017-01-01

A perennial herb of the Campanulaceae (bellflower) family, swamp harebell (Campanula californica) is endemic to the north and central coast of California. The California Department of Fish and Wildlife (CDFW) considers the species to be moderately threatened, and is concerned with the severity of impacts from land use activities, and the...

Swamp tours in Louisiana post Hurricane Katrina and Hurricane Rita

Treesearch

Dawn J. Schaffer; Craig A. Miller

2007-01-01

Hurricanes Katrina and Rita made landfall in southern Louisiana during August and September 2005. Prior to these storms, swamp tours were a growing sector of nature-based tourism that entertained visitors while teaching about local flora, fauna, and culture. This study determined post-hurricane operating status of tours, damage sustained, and repairs made. Differences...

Atlantic white-cedar being eliminated by excessive animal damage in south Jersey

Treesearch

S. Little; H. A. Somes

1965-01-01

Atlantic white-cedar, which grows in the swamps of the New Jersey Pine Region, is a prized timber species. Most areas now growing white-cedar have been clearcut 4 or 5 times since 1700. In contrast, the associated swamp hardwoods-red maple, blackgum, and sweetbay-rarely produce wood that is valuable enough to harvest.

Lead Transport into Bayou Trepagnier Wetlands in Louisiana, USA

Treesearch

Margaret S. Devall; Leonard B. Thien; Erik Ellgaard; George Flowers

2006-01-01

Establishment of a petroleum refinery in 1916 near the headwaters of Bayou Trepagnier with subsequent dredging of the bayou resulted in spoil banks containing high levels of Pb. A large swamp abuts the eastern bank of the bayou. Cores were taken from 15 baldcypress [Taxodium distichum (L.) Richard] trees growing in the swamp along a 610-m transect (...

Training the Future - Swamp Work Activities

NASA Image and Video Library

2017-07-19

In the Swamp Works laboratory at NASA's Kennedy Space Center in Florida, student interns such as Maddy Olson are joining agency scientists, contributing in the area of Exploration Research and Technology. Olson is majoring in mechanical engineering at the University of North Dakota. The agency attracts its future workforce through the NASA Internship, Fellowships and Scholarships, or NIFS, Program.

Training the Future - Swamp Work Activities

NASA Image and Video Library

2017-07-19

In the Swamp Works laboratory at NASA's Kennedy Space Center in Florida, student interns such as Kevin Murphy are joining agency scientists, contributing in the area of Exploration Research and Technology. Murphy is majoring in mechanical engineering at the University of Illinois at Urbana-Champaign. The agency attracts its future workforce through the NASA Internship, Fellowships and Scholarships, or NIFS, Program.

Training the Future - Swamp Work Activities

NASA Image and Video Library

2017-07-19

In the Swamp Works laboratory at NASA's Kennedy Space Center in Florida, student interns such as Andrew Thoesen are joining agency scientists, contributing in the area of Exploration Research and Technology. Thoesen is studying mechanical engineering at Arizona State University in Tempe, Arizona. The agency attracts its future workforce through the NASA Internship, Fellowships and Scholarships, or NIFS, Program

An analysis and comparison of LANDSAT-1, Skylab (S-192) and aircraft data for delineation of land-water cover types of the Green Swamp, Florida

NASA Technical Reports Server (NTRS)

Higer, A. L. (Principal Investigator); Coker, A. E.; Schmidt, N. F.; Reed, I. E.

1975-01-01

The author has identified the following significant results. LANDSAT 1 and Skylab (S192) data from the Green Swamp area of central Florida were categorized into five classes: water, cypress, other wetlands, pine, and pasture. These categories were compared with similar categories on a detailed vegetative map made using low altitude aerial photography. Agreement of LANDSAT and Skylab categorized data with the vegetation map was 87 percent and 83 percent respectively. The Green Swamp vegetative categories may be widespread but often consist of numerous small isolated areas, because LANDSAT has a greater resolution than Skylab, it is more favorable for mapping the small vegetative categories.

Study on aging of single pile in soft soil foundation

NASA Astrophysics Data System (ADS)

Chen, Tiejun; Cao, Haiying

2017-04-01

In this paper, the single pile under load is analyzed by using the Biot consolidation equation and the modified method of the coupling of the Komala - Huang model. The consolidation of soil is simulated by Biot consolidation theory, and the whole process of the deformation of single pile is presented in the paper by means of the modified Komala - Huang model. Some useful conclusions are obtained by analyzing the variation of the pore pressure and the settlement of the soil under the action of load.

Assessing the environmental availability of sulfamethoxazole and its acetylated metabolite in agricultural soils amended with compost and manure: an experimental and modeling study

NASA Astrophysics Data System (ADS)

Goulas, Anaïs; Sertillange, Nicolas; Garnier, Patricia; Dumény, Valérie; Bergheaud, Valérie; Benoit, Pierre; Haudin, Claire-Sophie

2017-04-01

The recycling of sludge compost and farmyard manure in agriculture can lead to the introduction of sulfonamide antibiotics and their acetylated metabolites into soils. The quality and the biodegradability of the exogenous organic matter (EOM) containing antibiotic residues is determinant for their environmental availability and fate in soils (Goulas et al., 2016). This study combined experimental and modeling approaches in order to: 1) assess the fraction of sulfamethoxazole (SMX) and N-acetyl-sulfamethoxazole (AcSMX) available in EOM-amended soils by using soft extractions (CaCl2, EDTA or cyclodextrin solutions) during a 28-day incubation; and 2) better understand the dynamics of sulfonamide residues in amended soils in connection with their availability and the mineralization of EOM organic matter thanks to the COP-Soil model (Geng et al. 2015). This model proposes several options to couple the biotransformation of organic pollutants (OP) with the decomposition of EOM in soil. The microbial degradation can be simulated by co-metabolism and specific-metabolism. The model also accounts for the formation of non-extractable residues (NER) via both physicochemical and microbial routes. The available fraction in both soil/EOM mixtures decreased from 56-96% and 31-63% initial 14C-activity for AcSMX and SMX, respectively, to reach 7-33% after 28 days. This high decrease in the first seven days was mainly due to the formation of NER that were more abundant in soil/manure mixtures than in the soil/compost ones. The three aqueous solutions differently extracted the available 14C-residues according to the incubation time, the EOM and the molecule. The mineralized fractions for both 14C-molecules were only 2-3% with a little more mineralization in the soil/manure mixtures than in the soil/compost. By using the COP-Soil model, the dynamics of EOM and OP were well described using parameter values specific to the organic matter mineralization, and this for the three soft extractants used. Others parameter values were common to both EOM and both sulfonamide compounds when coupling the dynamics of OP to EOM with the assumption of co-metabolism. The set of parameter values describing the pollutant fate strongly differed according to the soft extractant, confirming different mechanisms of extraction. Globally, the best OP simulations were obtained for the CaCl2-based extraction. Keywords Sulfonamides; environmental availability; recycling; organic matter; modeling References Goulas A. Haudin C.-S., Bergheaud V., Dumény V., Fehri S., Bourdat-Deschamps M, Nelieu S., Benoit P. 2016. A new extraction method to assess the environmental availability of ciprofloxacin in agricultural soil amended with exogenous organic matters. Chemosphere, 165, 460-469. Geng C., Haudin C.-S., Zhang Y., Lashermes G., Houot S., Garnier P.. 2015. Modelling the release of organic contaminants during compost decomposition in soil. Chemosphere, 119: 423-431.

The UK Soil Observatory (UKSO) and mySoil app: crowdsourcing and disseminating soil information.

NASA Astrophysics Data System (ADS)

Robinson, David; Bell, Patrick; Emmett, Bridget; Panagos, Panos; Lawley, Russell; Shelley, Wayne

2017-04-01

Digital technologies in terms of web based data portals and mobiles apps offer a new way to provide both information to the public, and to engage the public in becoming involved in contributing to the effort of collecting data through crowdsourcing. We are part of the Landpotential.org consortium which is a global partnership committed to developing and supporting the adoption of freely available technology and tools for sustainable land use management, monitoring, and connecting people across the globe. The mySoil app was launched in 2012 and is an example of a free mobile application downloadable from iTunes and Google Play. It serves as a gateway tool to raise interest in, and awareness of, soils. It currently has over 50,000 dedicated users and has crowd sourced more than 4000 data records. Recent developments have expanded the coverage of mySoil from the United Kingdom to Europe, introduced a new user interface and provided language capability, while the UKSO displays the crowd-sourced records from across the globe. We are now trying to identify which industry, education and citizen sectors are using these platforms and how they can be improved. Please help us by providing feedback or taking the survey on the UKSO website. www.UKSO.org The UKSO is a collaboration between major UK soil-data holders to provide maps, spatial data and real-time temporal data from observing platforms such as the UK soil moisture network. Both UKSO and mySoil have crowdsourcing capability and are slowly building global citizen science maps of soil properties such as pH and texture. Whilst these data can't replace professional monitoring data, the information they provide both stimulates public interest and can act as 'soft data' that can help support the interpretation of monitoring data, or guide future monitoring, identifying areas that don't correspond with current analysis. In addition, soft data can be used to map soils with machine learning approaches, such as SoilGrids.

Burkholderia paludis sp. nov., an Antibiotic-Siderophore Producing Novel Burkholderia cepacia Complex Species, Isolated from Malaysian Tropical Peat Swamp Soil.

PubMed

Ong, Kuan Shion; Aw, Yoong Kit; Lee, Learn Han; Yule, Catherine M; Cheow, Yuen Lin; Lee, Sui Mae

2016-01-01

A novel Gram negative rod-shaped bacterium, designated strain MSh1 T , was isolated from Southeast Pahang tropical peat swamp forest soil in Malaysia and characterized using a polyphasic taxonomy approach. The predominant cellular fatty acids (>10.0%) were C 16:0 (31.7%), C 17:0 cyclo (26.6%), and C 19:0 cyclo ω8c (16.1%). The polar lipids detected were phosphatidylglycerol, phosphatidylethanolamine, and diphosphatidylglycerol. The predominant ubiquinone was Q-8. This revealed that strain MSh1 T belongs to the genus Burkholderia . The type strain MSh1 T can be differentiated from other Burkholderia cepacia complex (Bcc) species by phylogenetic analysis of 16S rRNA gene sequence, multilocus sequence analysis (MLSA), average nucleotide identity (ANI) and biochemical tests. DNA-DNA relatedness values between strain MSh1 T and closely related type strains were below the 70% threshold value. Based on this polyphasic study of MSh1 T , it can be concluded that this strain represents a novel species within the Bcc, for which the name Burkholderia paludis sp. nov. is proposed. The type strain is MSh1 T (= DSM 100703 T = MCCC 1K01245 T ). The dichloromethane extract of MSh1 T exhibited antimicrobial activity against four Gram positive bacteria ( Enterococcus faecalis ATCC 29212, E. faecalis ATCC 700802, Staphylococcus aureus ATCC 29213, S. aureus ATCC 700699) and a Gram negative bacteria ( Escherichia coli ATCC 25922). Further purification work has led to the isolation of Compound 1, pyochelin. Pyochelin demonstrated antimicrobial activity against four S. aureus strains and three E . faecalis strains with MIC-values of 3.13 μg/ml and 6.26 μg/ml, respectively. SEM analysis showed that the cellular morphology of E. faecalis ATCC 700802 was not affected by pyochelin; suggesting that it might target the intracellular components. Pyochelin, a siderophore with antimicrobial activity might be useful in treating bacterial infections caused by S. aureus and E. faecalis , however further work has to be done.

Estimating Sources and Sinks of Methane from Soils in the Contiguous United States (CONUS)

NASA Astrophysics Data System (ADS)

Shu, S.; Jain, A. K.; Kheshgi, H. S.

2017-12-01

The global methane (CH4) budget estimated based on state-of-the-art models remains highly uncertain. Sources and sinks of CH4 from soils, including wetlands, are the most important source of uncertainty. Soils are estimated to account for about 45% of global CH4 emissions. At the same time oxidation of CH4 by soils is a significant sink, representing about 10% of the total sink. However, most regional and global scale modeling studies of soil CH4 fluxes have ignored the sink through soil oxidation and the source of CH4 emissions from the wet soils with shallow water tables. In this study, we link a bottom-up soil gas diffusion and CH4 biogeochemistry model to a land surface model, ISAM, to calculate the sources, emissions from both wetlands and non-wetlands, and sinks, soil oxidation, of CH4 from soils for the CONUS over the period 1900-2100. The newly developed soil CH4 model framework consists of a gas diffusion module with the vertically resolved soil hydrology (depth up to 3.5 m soil) and soil organic carbon (SOC) and CH4 biogeochemistry module. SOC profile is estimated by modeling vertical soil mixing and thus can represent the deep SOC content and estimate CH4 production from the deep non-wetland soil. For the diffusion calculations, we separately consider both the dissolved and gaseous O2 and CH4 at each soil layer. For CH4 biogeochemistry, we parameterize the production, soil oxidation, ebullition and aerenchyma transportation of CH4 for both seasonal/permanent wetland and wet soil. The SWAMP inundated fraction dataset with 8-day temporal resolution is incorporated to prescribe the extent of permanent and seasonal wetland extent for the recent decade. The model is first evaluated using a compilation of published CH4 site measurement data for CONUS. We then perform two different model experiments: 1) forced by the CRUNCEP climate data from 1900 to 2010 to estimate the contemporary CH4 emission and 2) forced by a climate projection of IPCC's highest representative concentration pathway (RCP8.5) from 2011 to 2100. Our study shows that soil oxidation has an important role attenuating the estimated natural CH4 source. We also find a wetter and warmer climate affects the dry soil CH4 sink and wet soil CH4 emissions and increases the estimated CH4 source over the CONUS.

A Holocene vegetation record from the Mississippi River Valley, southeastern Missouri

USGS Publications Warehouse

King, J.E.; Allen, W.H.

1977-01-01

Pollen preserved in a peat deposit from a large swamp, the Old Field in the Mississippi River Valley near Advance, Missouri, records radiocarbon-dated vegetation changes between 9000 and about 3000 years ago. The principal feature of both the percentage and influx pollen diagrams is the replacement of arboreal pollen, primarily Quercus, Fraxinus, and Cephalanthus, with Gramineae and NAP between 8700 and 5000 years BP. This vegetation shift is interpreted as reflecting a decrease in the extent of the Old Field swamp and its associated bottomland forest species along with the expansion of a grass-dominated herb community, as a result of a reduction in available ground water. The desiccation of the swamp during this period indicates a reduction in precipitation within the ground-water source area and a shift to a drier climate in the southern Midwest. The pollen suggests that the lowest water levels and driest climate in southeastern Missouri lasted from 8700 to 6500 years BP, at which time there is a partial reappearance of swamp species. Relatively dry conditions, however, continued until at least 5000 years BP. Although pollen influx data are lacking from the upper part of the profile, the relative pollen frequencies suggest an increase in trees after 5000 BP. The replacement of the arboreal vegetation by grasses and herbs between 8700 and 5000 years BP reflects the period of maximum expansion of the Prairie Peninsula in southeastern Missouri. The Old Field swamp provides the first pollen evidence that the vegetational changes along the southern border of the Prairie Peninsula were chronologically similar to those on the northern and northeastern margins. ?? 1977.

A plant-inspired robot with soft differential bending capabilities.

PubMed

Sadeghi, A; Mondini, A; Del Dottore, E; Mattoli, V; Beccai, L; Taccola, S; Lucarotti, C; Totaro, M; Mazzolai, B

2016-12-20

We present the design and development of a plant-inspired robot, named Plantoid, with sensorized robotic roots. Natural roots have a multi-sensing capability and show a soft bending behaviour to follow or escape from various environmental parameters (i.e., tropisms). Analogously, we implement soft bending capabilities in our robotic roots by designing and integrating soft spring-based actuation (SSBA) systems using helical springs to transmit the motor power in a compliant manner. Each robotic tip integrates four different sensors, including customised flexible touch and innovative humidity sensors together with commercial gravity and temperature sensors. We show how the embedded sensing capabilities together with a root-inspired control algorithm lead to the implementation of tropic behaviours. Future applications for such plant-inspired technologies include soil monitoring and exploration, useful for agriculture and environmental fields.

Restoration of a severely impacted riparian wetland system - The Pen Branch Project

Treesearch

Christopher Barton; Eric A. Nelson; Randall K. Kolka; Kenneth W. McLeod; William H. Conner; Michelle Lakly; Douglas Martin; John Wigginton; Carl C. Trettin; Joe Wisniewski

2000-01-01

The Savannah River Swamp is a 3020 ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy's Savannah River Site (SRS) near Aiken, SC (Fig. 1). Historically the swamp consisted of approximately 50% baldcypress-water tupelo stands, 40% mixed bottomland hardwood stands, and 10% shrub, marsh, and open water. Tributeries...

Variation in flood tolerance of container-grown seedlings of swamp white oak, bur oak, and white oak

Treesearch

Michael P. Walsh; J.W. Van Sambeek; Mark V. Coggeshall

2008-01-01

How much variation in flood tolerance exists among seedlings within oak species, given the flood frequency of sites from which acorns are collected, has been largely unexplored. Our studies examined initial growth and flood tolerance for seedlings of swamp white oak (Quercus bicolor Willd.), bur oak (Q. macrocarpa L.), and white...

Grafting influences on early acorn production in swamp white oak (Quercus bicolor Wild.)

Treesearch

Mark V. Coggeshall; J.W. Van Sambeek; H.E. Garrett

2008-01-01

Early fruiting of swamp white oak planting stock has been observed. The potential to exploit this trait for wildlife enhancement purposes was evaluated in a grafting study. Scions from both precocious and non-precocious ortets were grafted onto a series of related seedling rootstock sources. Acorn production was recorded through age 4 years. Acorn productivity of the...

Genetic diversity of infective larvae of Gnathostoma spinigerum (Nematoda: Gnathostomatidae) in freshwater swamp eels from Thailand.

PubMed

Eamsobhana, P; Wanachiwanawin, D; Roongruangchai, K; Song, S L; Yong, H S

2017-11-01

Human gnathostomiasis is a food-borne zoonosis caused by a tissue nematode of the genus Gnathostoma. The disease is highly endemic in Asia, including Thailand. The freshwater swamp eel (Monopterus albus), the second intermediate host of the gnathostome nematode, has an important role in transmitting the infection in Thailand. Surveys on the infective larvae of Gnathostoma spinigerum based on morphological features in freshwater swamp eels have been performed continuously and reported in Thailand. However, there is still limited molecular data on intra-species variations of the parasite. In this study, a total of 19 third-stage larvae of morphologically identified G. spinigerum were collected from 437 liver samples of freshwater swamp eels purchased from a large wholesale market in Bangkok, Thailand. Molecular characterization based on mitochondrial cytochrome c oxidase subunit I (COI) sequences was performed to elucidate their genetic variations and phylogenetic relationship. Among the 19 infective larvae recovered from these eels, 16 were sequenced successfully. Phylogenetic analyses inferred from the partial COI gene showed the presence of three distinct COI haplotypes. Our findings confirm the presence of G. spinigerum as the main species in Thailand.

Relationship between peat geochemistry and depositional environments, Cranberry Island, Maine

USGS Publications Warehouse

Raymond, R.; Cameron, C.C.; Cohen, A.D.

1987-01-01

The Heath, Great Cranberry Island, Maine, offers a unique locality for studying lateral and vertical relationships between radically different peat types within 1 km2. The majority of The Heath is a Sphagnum moss-dominated raised bog. Surrounding the raised bog is a swamp/marsh complex containing grass, sedge, Sphagnum moss, alder, tamarack, and skunk cabbage. Swamp/ marsh-deposited peat occurs both around the margins of The Heath and under Sphagnum-dominated peat, which was deposited within the raised bog. A third peat type, dominated by herbaceous aquatics, is present underlying the swamp/marsh-dominated peat but is not present as a dominant botanical community of The Heath. The three peat types have major differences in petrographic characteristics, ash contents, and associated minerals. Sulfur contents range from a low of 0.19 wt.% (dry) within the raised bog to a high of 4.44 wt% (dry) near the west end of The Heath, where swamp/marsh peat occurring directly behind a storm beach berm has been influenced by marine waters. The presence of major geochemical variations within a 1-km2 peat deposit suggests the need for in-depth characterization of potential peat resources prior to use. ?? 1987.

Finding and Using Wasted Water to Restore Baldcypress - Water Tupelo Swamps and Freshwater Marshes and Protect Against Salt Water Intrusion: A Case Study of the Lake Pontchartrain Basin

NASA Astrophysics Data System (ADS)

Shaffer, G. P.; Lane, R.; Day, J. W.; Barrett, S.

2017-12-01

We developed a geographic information system (GIS) containing substantial point and non-point freshwater sources along the North Shore of Lake Pontchartrain, from Lake Maurepas to the Pearl River, which potentially could be directed at degraded wetlands. Thus far, we have concentrated on municipal wastewater treatment facilities, subdivisions treating their own sewage, non-point source drainage features, and potential Mississippi River diversion sites. Most analysis, processing, and mapping were conducted in Arc GIS v9.2. Five classes of source water ranging from <25,000 to >100,000 gallons per day were mapped. These were color and size coded and the level of detail in the GIS varies according to aerial coverage. That is, the overall image is in broad brush and increasing detail is automatically provided as the user increases magnification The sources were then prioritized by size and distance from a marsh or swamp. Because assimilation wetlands into marshes in coastal Louisiana attract the introduced rodent nutria (Myocaster coypus) swamps were weighted higher than marshes. The top five sources were all wastewater facilities located near swamps.

Paleoecology of the Late Pennsylvanian-age Calhoun coal bed and implications for long-term dynamics of wetland ecosystems

USGS Publications Warehouse

Willard, D.A.; Phillips, T.L.; Lesnikowska, A.D.; DiMichele, W.A.

2007-01-01

Quantitative plant assemblage data from coal balls, miospores, megaspores, and compression floras from the Calhoun coal bed (Missourian) of the Illinois Basin (USA) are used to interpret spatial and temporal changes in plant communities in the paleo-peat swamp. Coal-ball and miospore floras from the Calhoun coal bed are dominated strongly by tree ferns, and pteridosperms and sigillarian lycopsids are subdominant, depending on geographic location within the coal bed. Although the overall composition of Calhoun peat-swamp assemblages is consistent both temporally and spatially, site-to-site differences and short-term shifts in species dominance indicate local topographic and hydrologic control on species composition within the broader context of the swamp. Statistical comparison of the Calhoun miospore assemblages with those from other Late Pennsylvanian coal beds suggests that the same basic species pool was represented in each peat-swamp landscape and that the relative patterns of dominance and diversity were persistent from site to site. Therefore, it appears that the relative patterns of proportional dominance stayed roughly the same from one coal bed to the next during Late Pennsylvanian glacially-driven climatic oscillations.

Seismic Hazard Maps for Seattle, Washington, Incorporating 3D Sedimentary Basin Effects, Nonlinear Site Response, and Rupture Directivity

USGS Publications Warehouse

Frankel, Arthur D.; Stephenson, William J.; Carver, David L.; Williams, Robert A.; Odum, Jack K.; Rhea, Susan

2007-01-01

This report presents probabilistic seismic hazard maps for Seattle, Washington, based on over 500 3D simulations of ground motions from scenario earthquakes. These maps include 3D sedimentary basin effects and rupture directivity. Nonlinear site response for soft-soil sites of fill and alluvium was also applied in the maps. The report describes the methodology for incorporating source and site dependent amplification factors into a probabilistic seismic hazard calculation. 3D simulations were conducted for the various earthquake sources that can affect Seattle: Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep earthquakes. The maps presented in this document used essentially the same set of faults and distributed-earthquake sources as in the 2002 national seismic hazard maps. The 3D velocity model utilized in the simulations was validated by modeling the amplitudes and waveforms of observed seismograms from five earthquakes in the region, including the 2001 M6.8 Nisqually earthquake. The probabilistic seismic hazard maps presented here depict 1 Hz response spectral accelerations with 10%, 5%, and 2% probabilities of exceedance in 50 years. The maps are based on determinations of seismic hazard for 7236 sites with a spacing of 280 m. The maps show that the most hazardous locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and along the inferred trace of the frontal fault of the Seattle fault zone. The next highest hazard is typically found for soft-soil sites in the Duwamish Valley south of the Seattle basin. In general, stiff-soil sites in the Seattle basin exhibit higher hazard than stiff-soil sites outside the basin. Sites with shallow bedrock outside the Seattle basin have the lowest estimated hazard for this frequency band.

Keep wetlands wet: the myth of sustainable development of tropical peatlands - implications for policies and management.

PubMed

Evers, Stephanie; Yule, Catherine M; Padfield, Rory; O'Reilly, Patrick; Varkkey, Helena

2017-02-01

Pristine tropical peat swamp forests (PSFs) represent a unique wetland ecosystem of distinctive hydrology which support unique biodiversity and globally significant stores of soil carbon. Yet in Indonesia and Malaysia, home to 56% of the world's tropical peatland, they are subject to considerable developmental pressures, including widespread drainage to support agricultural needs. In this article, we review the ecology behind the functioning and ecosystem services provided by PSFs, with a particular focus on hydrological processes as well as the role of the forest itself in maintaining those services. Drawing on this, we review the suitability of current policy frameworks and consider the efficacy of their implementation. We suggest that policies in Malaysia and Indonesia are often based around the narrative of oil palm and other major monocrops as drivers of prosperity and development. However, we also argue that this narrative is also being supported by a priori claims concerning the possibility of sustainability of peat swamp exploitation via drainage-based agriculture through the adherence to best management practices. We discuss how this limits their efficacy, uptake and the political will towards enforcement. Further, we consider how both narratives (prosperity and sustainability) clearly exclude important considerations concerning the ecosystem value of tropical PSFs which are dependent on their unimpacted hydrology. Current research clearly shows that the actual debate should be focused not on how to develop drainage-based plantations sustainably, but on whether the sustainable conversion to drainage-based systems is possible at all. © 2016 John Wiley & Sons Ltd.

From wetlands to wet spots: Environmental tracking and the fate of carboniferous elements in early permian tropical fl oras

USGS Publications Warehouse

DiMichele, W.A.; Tabor, N.J.; Chaney, D.S.; Nelson, W.J.

2006-01-01

Diverse wetland vegetation flourished at the margins of the Midland Basin in north-central Texas during the Pennsylvanian Period. Extensive coastal swamps and an ever-wet, tropical climate supported lush growth of pteridosperm, marattialean fern, lycopsid, and calamite trees, and a wide array of ground cover and vines. As the Pennsylvanian passed into the Permian, the climate of the area became drier and more seasonal, the great swamps disappeared regionally, and aridity spread. The climatic inferences are based on changes in sedimentary patterns and paleosols as well as the general paleobotanical trends. The lithological patterns include a change from a diverse array of paleosols, including Histosols (ever-wet waterlogged soils), in the late Pennsylvanian to greatly diminished paleosol diversity with poorly developed Vertisols by the Early-Middle Permian transition. In addition, coal seams were present with wide areal distribution in the late Pennsylvanian whereas beds of evaporates were common by the end of the Early Permian. During this climatic transition, wetland plants were confi ned to shrinking "wet spots" found along permanent streams where the vegetation they constituted remained distinct if increasingly depauperate in terms of species richness. By Leonardian (late Early Permian) time, most of the landscape was dominated by plants adapted to seasonal drought and a deep water table. Wetland elements were reduced to scattered pockets, dominated primarily by weedy forms and riparian specialists tolerant of flooding and burial. By the Middle Permian, even these small wetland pockets had disappeared from the region. ?? 2006 Geological Society of America.

The Effects of Historical Earthquakes on Cyzicus Ancient City

NASA Astrophysics Data System (ADS)

Adatepe, F.; Demirel, S.; Vardar, D.

2012-04-01

Cyzicus is one of the most important ancient settlement of Mysia region on Marmara coasts in Turkey. It's located on Belkis Tombolo which connects Kapıdağ (Arktonnesos) Peninsula to the shore. It was established by the King Cyzicus Kyzikos in B.C. 749 as a Miletos colony during the colonization movements of Ions. The main reason to determine the establishment place of Cyzicus was; a strong defense system formed by the natural conditions and the walls surrounding the city. In addition, from the documents, 3 natural harbor (one of them inner harbor) and one artificial canal in the ancient city has been designated. Because of these features, the ancient city had been developed by maritime trade and fisheries. And also, city's economy had grown due to its fertile soil. Works in marble that came from Marmara Island, were being effective in the artistic activities in the city. Due to the capital city of East Roman Empire was being Constantine (AD 324), the chance of Cyzicus was affected badly. Since its location on the south branch of the North Anatolian Fault zone in the Marmara Sea, ancient city was being ruined by a series of earthquakes. There were fifteen (15) destructive earthquakes occurred between AD 29 - 1887. For example the region had become a swamp because of AD 740 earthquake. At that time, despite metropolitan center pass through to Erdek, the city was not fully abandoned. In the end, the earthquake of 1064 had completely demolished Cyzicus. At the present day, this ancient city has come to the point to be lost in swamps, brushes and shrubs.

Organic Matter in Rivers: The Crossroads between Climate and Water Quality

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

Davisson, M L

2001-04-27

All surface waters in the world contain dissolved organic matter and its concentration depends on climate and vegetation. Dissolved organic carbon (DOC) is ten times higher in wetlands and swamps than in surface water of arctic, alpine, or arid climate. Climates of high ecosystem productivity (i.e., tropics) typically have soils with low organic carbon storage, but drain high dissolved organic loads to rivers. Regions with lower productivity (e.g. grasslands) typically have high soil carbon storage while adjacent rivers have high DOC contents. Most DOC in a free-flowing river is derived from leaching vegetation and soil organic matter, whereas in dammedmore » rivers algae may comprise a significant portion. Water chemistry and oxygen-18 abundance of river water, along with radiocarbon and carbon-13 isotope abundance measurements of DOC were used to distinguish water and water quality sources in the Missouri River watershed. Drinking water for the City of St. Louis incorporates these different sources, and its water quality depends mostly on whether runoff is derived from the upper or the lower watershed, with the lower watershed contributing water with the highest DOC. During drinking water chlorination, DOC forms carcinogenic by-products in proportion to the amount of DOC present. This has recently led the USEPA to propose federal regulation standards. Restoration of natural riparian habitat such as wetlands will likely increase DOC concentrations in river water.« less

Hydropedological assessment of a vertisol climosequence on the Gulf Coast Prairie Land Resource Area of Texas

NASA Astrophysics Data System (ADS)

Nordt, L. C.; Driese, S. G.

2009-04-01

Vertisols contain slickensides and wedge-shaped aggregates formed by shrink-swell processes during wet-dry cycles in seasonal climates. The dynamic distribution of macro- and microvoids as a by-product of this unique process, accompanied by microtopographic lows and highs, mitigate our ability to make accurate and precise interpretations of aquic and hydric conditions in these problematic soils. We studied Vertisols across a subhumid to humid climosequence to assess the formation of redoximorphic features on planar landscape positions in response to varying levels of rainfall. Approximately 1000 mm of MAP is required to form soft iron masses that then increase in abundance, and to shallower depths, with increasing rainfall. More than 1200 mm of MAP is needed to form iron pore linings, regardless of microlow or microhigh topographic position. Soft iron masses with diffuse boundaries become more abundant with higher rainfall in microlows, whereas masses with nondiffuse boundaries are more common in microhighs. Iron depletions do not correlate with rainfall in terms of abundance or depth of occurrence. Most soft iron masses form in oxygenated ped interiors as water tends to first saturate and reduce voids where iron depletions form. The quantity of crayfish burrows is strongly correlated with rainfall and first appears coincidentally with soft iron masses in microlows near 1000 mm of MAP. Dithionite-citrate extractable and ammonium-oxalate extractable iron oxides increase systematically with rainfall indicating frequent episodes of iron reduction and precipitation into pedogenic forms. It appears that Vertisols forming in these landscapes with MAP greater than 1200 mm should classify as Aquerts because of the presence of aquic conditions. These same soils may also meet the definition of hydric as one criterion for the identification of Federally protected wetlands. However, there is a considerable disjunct between protracted periods of saturation and limited periods of reduction in these soils. Non-Darcian bypass flow appears to be the principle mechanism governing the flux of water through these cracking soils where water first accumulates and then persists in microlow bowls.

Home range use by swamp rabbits (Sylvilagus aquaticus) in a frequently inundated bottomland forest

Treesearch

Patrick A. Zollner; Winston P. Smith; Leonard A. Brennan

2000-01-01

Home range size of six swamp rabbits in south-central Arkansas was estilnated by radio-telemetry from February 1991 through March 1992. The average home range size was significantly larger than previously reported estimates. This difference is partly attributable to the large number of observations per rabbit in our study, but may also be explained by our inclusion of...

Water quality in the southern Everglades and Big Cypress Swamp in the vicinity of the Tamiami Trail, 1996-97

USGS Publications Warehouse

Miller, Ronald L.; McPherson, Benjamin F.; Haag, Kim H.

1999-01-01

The quality of water flowing southward in the Everglades and Big Cypress Swamp was characterized by three synoptic surveys along an 80-mile section of the Tamiami Trail and along a 24-mile transect down the Shark River Slough, by monthly sampling of a background reference site in the central Big Cypress Swamp, and by sampling of fish tissue for contaminants at several sites near the Trail. The quality of water along the Trail is spatially variable due to natural and human influences. Concentrations of dissolved solids and common ions such as chloride and sulfate were lowest in the central and eastern Big Cypress Swamp and were higher to the west due to the effects of seawater, especially during the dry season, and to the east due to canal drainage from the northern Everglades. Concentrations of total phosphorus tended to decrease from west to east along the 80-mile section of the Trail, and were usually about 0.01 milligram per liter or less in the Everglades. Short-term loads (based on average discharge for 4 days) of total phosphorus and total Kjeldahl nitrogen (ammonia plus organic nitrogen) across four gaged sections of the Tamiami Trail were highest in the Everglades near the S-12 structures primarily due to the relatively greater discharges in that section. Concentrations of dissolved solids and total phosphorus at the central Big Cypress Swamp site increased significantly during the dry season as waters ponded. Effects of nearby, upstream agricultural activities were evident at a site in the western Big Cypress Swamp where relatively high concentrations of total phosphorus, total mercury, and dissolved organic carbon and high periphyton biomass accumulation rates were measured and where several pesticides were detected. The most frequently detected pesticides along the Trail were atrazine (14 detections), tebuthiuron (11 detections), and metolachlor (5 detections), and most concentrations were less than 0.1 microgram per liter. DDT compounds were the only pesticides detected in fish from five sites. Total DDT ranged from 5 to 6 micrograms per kilogram in largemouth bass and from 11 to 17 micrograms per kilogram in Florida gar.

New Insights on Water Buffalo Genomic Diversity and Post-Domestication Migration Routes From Medium Density SNP Chip Data.

PubMed

Colli, Licia; Milanesi, Marco; Vajana, Elia; Iamartino, Daniela; Bomba, Lorenzo; Puglisi, Francesco; Del Corvo, Marcello; Nicolazzi, Ezequiel L; Ahmed, Sahar S E; Herrera, Jesus R V; Cruz, Libertado; Zhang, Shujun; Liang, Aixin; Hua, Guohua; Yang, Liguo; Hao, Xingjie; Zuo, Fuyuan; Lai, Song-Jia; Wang, Shuilian; Liu, Ruyu; Gong, Yundeng; Mokhber, Mahdi; Mao, Yongjiang; Guan, Feng; Vlaic, Augustin; Vlaic, Bogdan; Ramunno, Luigi; Cosenza, Gianfranco; Ahmad, Ali; Soysal, Ihsan; Ünal, Emel Ö; Ketudat-Cairns, Mariena; Garcia, José F; Utsunomiya, Yuri T; Baruselli, Pietro S; Amaral, Maria E J; Parnpai, Rangsun; Drummond, Marcela G; Galbusera, Peter; Burton, James; Hoal, Eileen; Yusnizar, Yulnawati; Sumantri, Cece; Moioli, Bianca; Valentini, Alessio; Stella, Alessandra; Williams, John L; Ajmone-Marsan, Paolo

2018-01-01

The domestic water buffalo is native to the Asian continent but through historical migrations and recent importations, nowadays has a worldwide distribution. The two types of water buffalo, i.e., river and swamp, display distinct morphological and behavioral traits, different karyotypes and also have different purposes and geographical distributions. River buffaloes from Pakistan, Iran, Turkey, Egypt, Romania, Bulgaria, Italy, Mozambique, Brazil and Colombia, and swamp buffaloes from China, Thailand, Philippines, Indonesia and Brazil were genotyped with a species-specific medium-density 90K SNP panel. We estimated the levels of molecular diversity and described population structure, which revealed historical relationships between populations and migration events. Three distinct gene pools were identified in pure river as well as in pure swamp buffalo populations. Genomic admixture was seen in the Philippines and in Brazil, resulting from importations of animals for breed improvement. Our results were largely consistent with previous archeological, historical and molecular-based evidence for two independent domestication events for river- and swamp-type buffaloes, which occurred in the Indo-Pakistani region and close to the China/Indochina border, respectively. Based on a geographical analysis of the distribution of diversity, our evidence also indicated that the water buffalo spread out of the domestication centers followed two major divergent migration directions: river buffaloes migrated west from the Indian sub-continent while swamp buffaloes migrated from northern Indochina via an east-south-eastern route. These data suggest that the current distribution of water buffalo diversity has been shaped by the combined effects of multiple migration events occurred at different stages of the post-domestication history of the species.

Larval Gnathostoma spinigerum Detected in Asian Swamp Eels, Monopterus albus, Purchased from a Local Market in Yangon, Myanmar.

PubMed

Chai, Jong-Yil; Sohn, Woon-Mok; Na, Byoung-Kuk; Park, Jong-Bok; Jeoung, Hoo-Gn; Hoang, Eui-Hyug; Htoon, Thi Thi; Tin, Htay Htay

2015-10-01

The present study was performed to determine the infection status of swamp eels with Gnathostoma sp. larvae in Myanmar. We purchased total 37 Asian swamp eels, Monopterus albus, from a local market in Yangon in June and December 2013 and 2014. All collected eels were transferred with ice to our laboratory and each of them was examined by the artificial digestion technique. A total of 401 larval gnathostomes (1-96 larvae/eel) were detected in 33 (89.2%) swamp eels. Most of the larvae (n=383; 95.5%) were found in the muscle. The remaining 18 larvae were detected in the viscera. The advanced third-stage larvae (AdL3) were 2.3-4.4 mm long and 0.25-0.425 mm wide. The characteristic head bulb (0.093 × 0.221 mm in average size) with 4 rows of hooklets, muscular long esophagus (1.025 mm), and 2 pairs of cervical sacs (0.574 mm) were observed by light microscopy. The average number of hooklets in the 1st, 2nd, 3rd, and 4th rows was 41, 45, 48, and 51, respectively. As scanning electron microscopic findings, the characteristic 4-5 rows of hooklets on the head bulb, a cervical papilla, tegumental spines regularly arranged in the transverse striations, and an anus were well observed. Based on these morphological characters, they were identified as the AdL3 of Gnathostoma spinigerum. By the present study, it has been confirmed for the first time that Asian swamp eels, M. albus, from Yangon, Myanmar are heavily infected with G. spinigerum larvae.

Larval Gnathostoma spinigerum Detected in Asian Swamp Eels, Monopterus albus, Purchased from a Local Market in Yangon, Myanmar

PubMed Central

Chai, Jong-Yil; Sohn, Woon-Mok; Na, Byoung-Kuk; Park, Jong-Bok; Jeoung, Hoo-Gn; Hoang, Eui-Hyug; Htoon, Thi Thi; Tin, Htay Htay

2015-01-01

The present study was performed to determine the infection status of swamp eels with Gnathostoma sp. larvae in Myanmar. We purchased total 37 Asian swamp eels, Monopterus albus, from a local market in Yangon in June and December 2013 and 2014. All collected eels were transferred with ice to our laboratory and each of them was examined by the artificial digestion technique. A total of 401 larval gnathostomes (1-96 larvae/eel) were detected in 33 (89.2%) swamp eels. Most of the larvae (n=383; 95.5%) were found in the muscle. The remaining 18 larvae were detected in the viscera. The advanced third-stage larvae (AdL3) were 2.3-4.4 mm long and 0.25-0.425 mm wide. The characteristic head bulb (0.093 × 0.221 mm in average size) with 4 rows of hooklets, muscular long esophagus (1.025 mm), and 2 pairs of cervical sacs (0.574 mm) were observed by light microscopy. The average number of hooklets in the 1st, 2nd, 3rd, and 4th rows was 41, 45, 48, and 51, respectively. As scanning electron microscopic findings, the characteristic 4-5 rows of hooklets on the head bulb, a cervical papilla, tegumental spines regularly arranged in the transverse striations, and an anus were well observed. Based on these morphological characters, they were identified as the AdL3 of Gnathostoma spinigerum. By the present study, it has been confirmed for the first time that Asian swamp eels, M. albus, from Yangon, Myanmar are heavily infected with G. spinigerum larvae. PMID:26537042

New Insights on Water Buffalo Genomic Diversity and Post-Domestication Migration Routes From Medium Density SNP Chip Data

PubMed Central

Colli, Licia; Milanesi, Marco; Vajana, Elia; Iamartino, Daniela; Bomba, Lorenzo; Puglisi, Francesco; Del Corvo, Marcello; Nicolazzi, Ezequiel L.; Ahmed, Sahar S. E.; Herrera, Jesus R. V.; Cruz, Libertado; Zhang, Shujun; Liang, Aixin; Hua, Guohua; Yang, Liguo; Hao, Xingjie; Zuo, Fuyuan; Lai, Song-Jia; Wang, Shuilian; Liu, Ruyu; Gong, Yundeng; Mokhber, Mahdi; Mao, Yongjiang; Guan, Feng; Vlaic, Augustin; Vlaic, Bogdan; Ramunno, Luigi; Cosenza, Gianfranco; Ahmad, Ali; Soysal, Ihsan; Ünal, Emel Ö.; Ketudat-Cairns, Mariena; Garcia, José F.; Utsunomiya, Yuri T.; Baruselli, Pietro S.; Amaral, Maria E. J.; Parnpai, Rangsun; Drummond, Marcela G.; Galbusera, Peter; Burton, James; Hoal, Eileen; Yusnizar, Yulnawati; Sumantri, Cece; Moioli, Bianca; Valentini, Alessio; Stella, Alessandra; Williams, John L.; Ajmone-Marsan, Paolo

2018-01-01

The domestic water buffalo is native to the Asian continent but through historical migrations and recent importations, nowadays has a worldwide distribution. The two types of water buffalo, i.e., river and swamp, display distinct morphological and behavioral traits, different karyotypes and also have different purposes and geographical distributions. River buffaloes from Pakistan, Iran, Turkey, Egypt, Romania, Bulgaria, Italy, Mozambique, Brazil and Colombia, and swamp buffaloes from China, Thailand, Philippines, Indonesia and Brazil were genotyped with a species-specific medium-density 90K SNP panel. We estimated the levels of molecular diversity and described population structure, which revealed historical relationships between populations and migration events. Three distinct gene pools were identified in pure river as well as in pure swamp buffalo populations. Genomic admixture was seen in the Philippines and in Brazil, resulting from importations of animals for breed improvement. Our results were largely consistent with previous archeological, historical and molecular-based evidence for two independent domestication events for river- and swamp-type buffaloes, which occurred in the Indo-Pakistani region and close to the China/Indochina border, respectively. Based on a geographical analysis of the distribution of diversity, our evidence also indicated that the water buffalo spread out of the domestication centers followed two major divergent migration directions: river buffaloes migrated west from the Indian sub-continent while swamp buffaloes migrated from northern Indochina via an east-south-eastern route. These data suggest that the current distribution of water buffalo diversity has been shaped by the combined effects of multiple migration events occurred at different stages of the post-domestication history of the species. PMID:29552025

Newly Isolated Paenibacillus tyrfis sp. nov., from Malaysian Tropical Peat Swamp Soil with Broad Spectrum Antimicrobial Activity

PubMed Central

Aw, Yoong-Kit; Ong, Kuan-Shion; Lee, Learn-Han; Cheow, Yuen-Lin; Yule, Catherine M.; Lee, Sui-Mae

2016-01-01

Emergence of antimicrobial resistance coupled with the slowdown in discovery of new antimicrobial compounds points to serious consequences for human health. Therefore, scientists are looking for new antimicrobial compounds from unique and understudied ecosystems such as tropical peat swamp forests. Over the course of isolating antimicrobial producing bacteria from North Selangor tropical peat swamp forest, Malaysia, a Gram variable, rod shaped, endospore forming, facultative anaerobic novel strain MSt1T that exerts potent and broad spectrum antimicrobial activity was isolated. Phylogenetic analysis using 16S rRNA gene sequences showed that strain MSt1T belonged to the genus Paenibacillus with the highest similarity to Paenibacillus elgii SD17T (99.5%). Whole genome comparison between strain MSt1T with its closely related species using average nucleotide identity (ANI) revealed that similarity between strain MSt1T with P. elgii B69 (93.45%) and Paenibacillus ehimensis A2 (90.42%) was below the recommended threshold of 95%. Further analysis using in silico pairwise DDH also showed that similarity between strain MSt1T with P. elgii B69 (55.4%) and P. ehimensis A2 (43.7%) was below the recommended threshold of 70%. Strain MSt1T contained meso-diaminopilemic acid in the cell wall and MK-7 as the major menaquinone. The major fatty acids of strain MSt1T were anteiso-C15:0 (48.2%) and C16:0 (29.0%) whereas the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unknown lipid, two unknown glycolipids, and one unknown phospholipid. Total DNA G+C content of strain MSt1T was 51.5 mol%. The extract from strain MSt1T exerted strong antimicrobial activity against Escherichia coli ATCC 25922 (MIC = 1.5 μg/mL), MRSA ATCC 700699 (MIC = 25 μg/mL) and Candida albicans IMR (MIC = 12.5 μg/mL). Partially purified active fraction exerted a strong effect against E. coli ATCC 25922 resulting in cell rupture when viewed with SEM. Based on distinctive taxonomic differences between strain MSt1T when compared to its closely related type species, we propose that strain MSt1T represents a novel species within the genus of Paenibacillus, for which the name Paenibacillus tyrfis sp. nov. (= DSM 100708T = MCCC 1K01247T) is proposed. PMID:26973605

Transpiration and root development of urban trees in structural soil stormwater reservoirs.

PubMed

Bartens, Julia; Day, Susan D; Harris, J Roger; Wynn, Theresa M; Dove, Joseph E

2009-10-01

Stormwater management that relies on ecosystem processes, such as tree canopy interception and rhizosphere biology, can be difficult to achieve in built environments because urban land is costly and urban soil inhospitable to vegetation. Yet such systems offer a potentially valuable tool for achieving both sustainable urban forests and stormwater management. We evaluated tree water uptake and root distribution in a novel stormwater mitigation facility that integrates trees directly into detention reservoirs under pavement. The system relies on structural soils: highly porous engineered mixes designed to support tree root growth and pavement. To evaluate tree performance under the peculiar conditions of such a stormwater detention reservoir (i.e., periodically inundated), we grew green ash (Fraxinus pennsylvanica Marsh.) and swamp white oak (Quercus bicolor Willd.) in either CUSoil or a Carolina Stalite-based mix subjected to three simulated below-system infiltration rates for two growing seasons. Infiltration rate affected both transpiration and rooting depth. In a factorial experiment with ash, rooting depth always increased with infiltration rate for Stalite, but this relation was less consistent for CUSoil. Slow-drainage rates reduced transpiration and restricted rooting depth for both species and soils, and trunk growth was restricted for oak, which grew the most in moderate infiltration. Transpiration rates under slow infiltration were 55% (oak) and 70% (ash) of the most rapidly transpiring treatment (moderate for oak and rapid for ash). We conclude this system is feasible and provides another tool to address runoff that integrates the function of urban green spaces with other urban needs.

Excavation-caused extra deformation of existing masonry residence in soft soil region

NASA Astrophysics Data System (ADS)

Tang, Y.; Franceschelli, S.

2017-04-01

Growing need for construction of infrastructures and buildings in fast urbanization process creates challenges of interaction between buildings under construction and adjacent existing buildings. This paper presents the mitigation of contradiction between two parties who are involved the interaction using civil engineering techniques. Through the in-depth analysis of the results of monitoring surveys and enhanced accuracy and reliability of surveys, a better understanding of the behavior of deformable buildings is achieved. Combination with the original construction documents, the two parties agree that both of them are responsible for building damages and a better understanding for the rehabilitation of the existing buildings is focused on. Two cases studies are used to demonstrate and describe the importance of better understanding of the behavior of existing buildings and their rehabilitations. The objective of this study is to insight into mechanisms of soil-structure interaction for buildings adjacent to deep excavations, which can result in a damage in existing masonry residence, and to take the optimized measures to make deep excavations safety and economic and adjacent buildings keep good serviceability in urban areas with soft soil conditions.

Challenges in Construction Over Soft Soil - Case Studies in Malaysia

NASA Astrophysics Data System (ADS)

Mohamad, N. O.; Razali, C. E.; Hadi, A. A. A.; Som, P. P.; Eng, B. C.; Rusli, M. B.; Mohamad, F. R.

2016-07-01

Construction on soft ground area is a great challenge in the field of geotechnical engineering. Many engineering problems in the form of slope instability, bearing capacity failure or excessive settlement could occur either during or after the construction phase due to low shear strength and high compressibility of this soil. As main technical agencies responsible for implementation of development projects for Government of Malaysia, Public Works Department has vast experience in dealing with this problematic soil over the years. This paper discussed and elaborate on the engineering problems encountered in construction projects that have been carried out by PWD, namely Core Facilities Building of Polytechnic Kota Kinabalu in Sabah and Hospital Tengku Ampuan Rahimah Integration Quarters in Klang, Selangor. Instability of the ground during construction works had caused delay and cost overrun in completion of the project in Selangor, whereas occurrence of continuous post construction settlement had affected the integrity and serviceability of the building in Sabah. The causes of failure and proposed rehabilitation work for both projects also will be discussed in brief.

Results of laboratory testing for diphacinone in seawater, fish, invertebrates, and soil following aerial application of rodenticide on Lehua Island, Kauai County, Hawaii, January 2009

USGS Publications Warehouse

Orazio, Carl E.; Tanner, Michael J.; Swenson, Chris; Herod, Jeffrey J.; Dunlevy, Peter; Gale, Robert W.

2009-01-01

In January 2009, rodenticide bait (Ramik Green pellets) containing the active ingredient diphacinone was aerially applied to Lehua Island. Reported herein are the results of laboratory analyses to determine diphacinone concentrations in samples of seawater, fillet of fish, soft tissue of limpets (opihi), whole-body crabs, and soil collected from Lehua Island, Kauai County, Hawaii, after aerial application of the rodenticide bait. Diphacinone was specifically chosen because of its low toxicity to nontarget organisms. Its use on Lehua Island is the second time it has ever been used for an aerial application to eradicate rodents. Testing of the Lehua Island samples for diphacinone utilized high-performance liquid chromatography with photodiode array detection. No detectable concentrations of diphacinone were found in any of the samples from Lehua Island. The limits of detection for diphacinone were 0.4 nanograms per milliliter (parts per billion) seawater, 15 nanograms per gram (dry weight) soil, 20 nanograms per gram (parts per billion) fish fillet, 13 nanograms per gram whole crab, and 34 nanograms per gram soft tissue limpet.

Optimising value from the soft re-use of brownfield sites.

PubMed

Bardos, R Paul; Jones, Sarah; Stephenson, Ian; Menger, Pierre; Beumer, Victor; Neonato, Francesca; Maring, Linda; Ferber, Uwe; Track, Thomas; Wendler, Katja

2016-09-01

Soft re-use of brownfields describes intended temporary or final re-uses of brownfield sites which are not based on built constructions or infrastructure ('hard' re-use). Examples of soft re-uses include the creation of public green space. These are essentially uses where the soil is not sealed. Often the case for soft re-use of brownfields has not been easy to demonstrate in strictly financial terms. The purpose of this paper is to describe a value based approach to identify and optimise services provided by the restoration of brownfields to soft re-uses, on a permanent or interim basis. A 'Brownfield Opportunity Matrix' is suggested as means of identifying and discussing soft restoration opportunities. The use of 'sustainability linkages' is suggested as a means of understanding the sustainability of the services under consideration and providing a structure for the overall valuation of restoration work, for example as part of design or option appraisal processes, or to support the solicitation of interest in a project. Copyright © 2015 Elsevier B.V. All rights reserved.

A Physics Based Vehicle Terrain Interaction Model for Soft Soil off-Road Vehicle Simulations

DTIC Science & Technology

2012-01-01

assumed terrain deformation, use of empirical relationships for the deformation, or finite/discrete element approaches for the terrain. A real-time...vertical columns of soil, and the deformation of each is modeled using visco-elasto-plastic compressibility relationships that relate subsoil pressures to...produced by tractive and turning forces will also be incorporated into the model. Both the vertical and horizontal force/displacement relationships

Nariva Swamp Ramsar Site, Trinidad and Tobago (West Indies) Wetland Habitat Restoration Initiative

Treesearch

Montserrat Carbonell; Nadra Nathai-Gyan

2005-01-01

Trinidad and Tobago, a twin island nation, is the most southerly of the Caribbean islands and lies just 11 km off the coast of Venezuela, near the Orinoco delta. Trinidad, the larger of the two islands, is approximately 5,000 km² and the Nariva Swamp is located on its eastern coast (fig. 1). In 1993, this site was designated as a wetland of international...

Deforestation and reforestation analysis from land-use changes in North Sumatran Mangroves, 1990-2015

NASA Astrophysics Data System (ADS)

Basyuni, M.; Sulistiyono, N.

2018-02-01

Mangrove forest plays a critical role in the context of climate change in tropical and subtropical regions. The present study analyzed the deforestation and reforestation from land-use and land-cover changes from 1990, 2000, 2009 and 2015 in North Sumatran mangrove forest, Indonesia. The land-use/land-cover consists of thirteen classes namely, primary mangrove forest, secondary mangrove forest, shrub, swamp shrub, swamp, settlement, paddy field, oil palm plantation, aquaculture, dry land farming, mixed dry land farming, mining, and barren land. Results showed that primary mangrove forests significantly decreased 61.21% from 1990 to 2015, mostly deforestation was derived from 1990 to 2000 to be secondary mangrove forest and swamp shrub. During 25 years observed, no reforestation was noted in the primary mangrove forest. Similarly, secondary mangrove forest had been degraded from 56,128.75 ha in 1990 to only 35,768.48 ha in 2015. Drivers of deforestation found in secondary mangrove forests were aquaculture (43.32%), barren land (32.56%), swamp shrub (10.88%), and oil palm plantation (5.17%). On the other hand, reforested activity was occurred only 701.83 ha from 1990 to 2015, while the nonforest use has been increased. These data are likely to contribute towards coastal management planning, conservation, and rehabilitation of degraded mangrove forests.

The Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar.

PubMed

Eppley, Timothy M; Donati, Giuseppe; Ramanamanjato, Jean-Baptiste; Randriatafika, Faly; Andriamandimbiarisoa, Laza N; Rabehevitra, David; Ravelomanantsoa, Robertin; Ganzhorn, Jörg U

2015-01-01

The lemurs of Madagascar are among the most threatened mammalian taxa in the world, with habitat loss due to shifting cultivation and timber harvest heavily contributing to their precarious state. Deforestation often leads to fragmentation, resulting in mixed-habitat matrices throughout a landscape where disturbed areas are prone to invasion by exotic plants. Our study site, the Mandena littoral forest (southeast Madagascar), is a matrix of littoral forest, littoral swamp, and Melaleuca swamp habitats. Here, Melaleuca quinquenervia has invaded the wetland ecosystem, creating a mono-dominant habitat that currently provides the only potential habitat corridor between forest fragments. We sought to understand the role of this invasive Melaleuca swamp on the behavioral ecology of a threatened, small-bodied folivore, the southern bamboo lemur (Hapalemur meridionalis). We collected botanical and behavioral data on four groups of H. meridionalis between January and December 2013. Our results confirm Melaleuca swamp as an important part of their home range: while lemurs seasonally limited activities to certain habitats, all groups were capable of utilizing this invasive habitat for feeding and resting. Furthermore, the fact that Hapalemur use an invasive plant species as a dispersal corridor increases our knowledge of their ecological flexibility, and may be useful in the conservation management of remaining threatened populations.

Habitat-specific foraging of prothonotary warblers: Deducing habitat quality

USGS Publications Warehouse

Lyons, J.E.

2005-01-01

Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

The Use of an Invasive Species Habitat by a Small Folivorous Primate: Implications for Lemur Conservation in Madagascar

PubMed Central

Eppley, Timothy M.; Donati, Giuseppe; Ramanamanjato, Jean-Baptiste; Randriatafika, Faly; Andriamandimbiarisoa, Laza N.; Rabehevitra, David; Ravelomanantsoa, Robertin; Ganzhorn, Jörg U.

2015-01-01

The lemurs of Madagascar are among the most threatened mammalian taxa in the world, with habitat loss due to shifting cultivation and timber harvest heavily contributing to their precarious state. Deforestation often leads to fragmentation, resulting in mixed-habitat matrices throughout a landscape where disturbed areas are prone to invasion by exotic plants. Our study site, the Mandena littoral forest (southeast Madagascar), is a matrix of littoral forest, littoral swamp, and Melaleuca swamp habitats. Here, Melaleuca quinquenervia has invaded the wetland ecosystem, creating a mono-dominant habitat that currently provides the only potential habitat corridor between forest fragments. We sought to understand the role of this invasive Melaleuca swamp on the behavioral ecology of a threatened, small-bodied folivore, the southern bamboo lemur (Hapalemur meridionalis). We collected botanical and behavioral data on four groups of H. meridionalis between January and December 2013. Our results confirm Melaleuca swamp as an important part of their home range: while lemurs seasonally limited activities to certain habitats, all groups were capable of utilizing this invasive habitat for feeding and resting. Furthermore, the fact that Hapalemur use an invasive plant species as a dispersal corridor increases our knowledge of their ecological flexibility, and may be useful in the conservation management of remaining threatened populations. PMID:26536667

Vegetation correlates of gibbon density in the peat-swamp forest of the Sabangau catchment, Central Kalimantan, Indonesia.

PubMed

Hamard, Marie; Cheyne, Susan M; Nijman, Vincent

2010-06-01

Understanding the complex relationship between primates and their habitats is essential for effective conservation plans. Peat-swamp forest has recently been recognized as an important habitat for the Southern Bornean gibbon (Hylobates albibarbis), but information is scarce on the factors that link gibbon density to characteristics of this unique ecosystem. Our aims in this study were firstly to estimate gibbon density in different forest subtypes in a newly protected, secondary peat-swamp forest in the Sabangau Catchment, Indonesia, and secondly to identify which vegetation characteristics correlate with gibbon density. Data collection was conducted in a 37.1 km(2) area, using auditory sampling methods and vegetation "speed plotting". Gibbon densities varied between survey sites from 1.39 to 3.92 groups/km(2). Canopy cover, tree height, density of large trees and food availability were significantly correlated with gibbon density, identifying the preservation of tall trees and good canopy cover as a conservation priority for the gibbon population in the Sabangau forest. This survey indicates that selective logging, which specifically targets large trees and disrupts canopy cover, is likely to have adverse effects on gibbon populations in peat-swamp forests, and calls for greater protection of these little-studied ecosystems. (c) 2010 Wiley-Liss, Inc.

Peat Soil Stabilization using Lime and Cement

NASA Astrophysics Data System (ADS)

Zambri, Nadhirah Mohd; Ghazaly, Zuhayr Md.

2018-03-01

This paper presents a study of the comparison between two additive Lime and Cement for treating peat soil in term of stabilization. Peat and organic soils are commonly known for their high compressibility, extremely soft, and low strength. The aim of this paper is to determine the drained shear strength of treated peat soil from Perlis for comparison purposes. Direct Shear Box Test was conducted to obtain the shear strength for all the disturbed peat soil samples. The quick lime and cement was mixed with peat soil in proportions of 10% and 20% of the dry weight peat soil. The experiment results showed that the addition of additives had improved the strength characteristics of peat soil by 14% increment in shear strength. In addition, the mixture of lime with peat soil yield higher result in shear strength compared to cement by 14.07% and 13.5% respectively. These findings indicate that the lime and cement is a good stabilizer for peat soil, which often experienced high amount of moisture content.

Enhanced organic contaminants accumulation in crops: Mechanisms, interactions with engineered nanomaterials in soil.

PubMed

Wu, Xiang; Wang, Wei; Zhu, Lizhong

2018-05-02

The mechanism of enhanced accumulation of organic contaminants in crops with engineered nanomaterials (ENMs) were investigated by co-exposure of crops (Ipomoea aquatica Forsk (Swamp morning-glory), Cucumis sativus L. (cucumber), Zea mays L. (corn), Spinacia oleracea L. (spinach) and Cucurbita moschata (pumpkin))to a range of chemicals (polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs) and polybrominated diphenyl ether (PBDE)) and ENMs (TiO 2 , Ag, Al 2 O 3 , graphene, carbon nanotubes (CNTs)) in soil. Induced by 50 mg kg -1 graphene co-exposure, the increase range of BDE-209, BaP, p,p'-DDE, HCB, PYR, FLU, ANT, and PHEN in the plants were increased in the range of 7.51-36.42, 5.69-32.77, 7.09-59.43, 11.61-66.73, 4.58-57.71, 5.79-109.07, 12.85-109.76, and15.57-127.75 ng g -1 , respectively. The contaminants in ENMs-spiked and control soils were separated into bioavailable, bound and residual fractions using a sequential ultrasonic extraction procedure (SUEP) to investigate the mechanism of the enhanced accumulation. The bioavailable fraction in spiked soils showed no significant difference (p > 0.05) from that in the control, while the bound fraction increased in equal proportion (p > 0.05) to the reduction in the residual fraction. These results implied that ENMs can competitively adsorbed the bound of organic contaminants from soil and co-transferred into crops, followed by a portion of the residual fraction transferred to the bound fraction to maintain the balance of different fractions in soils. The mass balance was all higher than 98.5%, indicating the portion of degraded contaminants was less than 1.5%. These findings could expand our knowledge about the organic contaminants accumulation enhancement in crops with ENMs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Out-of-plane (SH) soil-structure interaction: a shear wall with rigid and flexible ring foundation

NASA Astrophysics Data System (ADS)

Le, Thang; Lee, Vincent W.; Luo, Hao

2016-02-01

Soil-structure interaction (SSI) of a building and shear wall above a foundation in an elastic half-space has long been an important research subject for earthquake engineers and strong-motion seismologists. Numerous papers have been published since the early 1970s; however, very few of these papers have analytic closed-form solutions available. The soil-structure interaction problem is one of the most classic problems connecting the two disciplines of earthquake engineering and civil engineering. The interaction effect represents the mechanism of energy transfer and dissipation among the elements of the dynamic system, namely the soil subgrade, foundation, and superstructure. This interaction effect is important across many structure, foundation, and subgrade types but is most pronounced when a rigid superstructure is founded on a relatively soft lower foundation and subgrade. This effect may only be ignored when the subgrade is much harder than a flexible superstructure: for instance a flexible moment frame superstructure founded on a thin compacted soil layer on top of very stiff bedrock below. This paper will study the interaction effect of the subgrade and the superstructure. The analytical solution of the interaction of a shear wall, flexible-rigid foundation, and an elastic half-space is derived for incident SH waves with various angles of incidence. It found that the flexible ring (soft layer) cannot be used as an isolation mechanism to decouple a superstructure from its substructure resting on a shaking half-space.

Panoramic Okavango Swamp, Botswana and Fires in Angola, Africa

NASA Image and Video Library

1991-08-11

In this panoramic view of the Okavango Swamp, Botswana, (19.0S, 22.0E), the Okavango River, seen in sunglint, flows into a topographic trough to form an inland delta. Water, trapped in the meandering delta distributaries is evaporated or transpired by vegetation. In Angola to the north, the many fires of the seasonal burning of savannah vegetation for land clearing, in preparation for agriculture, has filled the atmosphere with haze and smoke.

Training the Future - Swamp Work Activities

NASA Image and Video Library

2017-07-19

In the Swamp Works laboratory at NASA's Kennedy Space Center in Florida, student interns such as Thomas Muller, left, and Austin Langdon are joining agency scientists, contributing in the area of Exploration Research and Technology. Muller is pursuing a degree in computer engineering and control systems and Florida Tech. Langdon is an electrical engineering major at the University of Kentucky. The agency attracts its future workforce through the NASA Internship, Fellowships and Scholarships, or NIFS, Program.

New Space Technology Development

NASA Technical Reports Server (NTRS)

Mueller, Rob

2014-01-01

Visitors from Moon Express, a privately funded commercial space company, will be visiting KSC Swamp Works. This presentation includes a high-level introduction to NASA and commercial partnerships, as well as brief background on the moon - what we used to think about it hundreds of years ago, and what we know today with advanced technologies.***This third part being added includes Swamp Works technical capabilities and has a high-level overview of a selection of projects.***

Evolution of fluvial styles in the Eocene Wasatch Formation, Powder River Basin, Wyoming

USGS Publications Warehouse

Warwick, Peter D.; Flores, Romeo M.; Ethridge, Frank G.; Flores, Romeo M.

1987-01-01

Vertical and lateral facies changes in the lower part of the Eocene Wasatch Formation in the Powder River Basin, Wyoming represent an evolution of fluvial systems that varied from meandering to anastomosing. The meandering facies in the lower part of the study interval formed in a series of broad meanderbelts in a northnorthwestflowing system. Upon abandonment this meanderbelt facies served as a topographic high on which a raised or ombrotrophic Felix peat swamp developed. Peat accumulated until compaction permitted encroachment of crevasse splays from an adjoining transitional facies which consists of deposits of a slightly sinuous fluvial system. Crevasse splays eventually prograded over the peat swamp that was partly covered by lakes. Bifurcation, reunification, and transformation of crevasse channels into major conduits produced an anastomosing system that was characterized by diverging and converging channels separated by floodbasins drowned by lakes and partly covered swamps.

Estimation of daily age and timing of hatching of exotic Asian swamp eels Monopterus albus (Zuiew, 1793) in a backwater marsh of the Chattahoochee River, Georgia, USA

USGS Publications Warehouse

Long, James M.; Lafleur, C.

2011-01-01

Otoliths were used to estimate daily age, growth, and hatching date of the exotic Asian swamp eel (Monopterus albus) captured from a backwater marsh of the Chattahoochee River, Georgia, USA. The eels were sampled using leaf litter traps (N = 140) from 17 July to 28 August 2008. The captured (N = 15) Asian swamp eels ranged in total length from 4.9 cm to 12.2 cm, and were estimated to be from 21 to 51 days old (N = 13), and hatched from 13 June to 7 August 2008. Assuming linear growth, these individuals grew an average rate of 0.2 cm per day. To the authors' knowledge, this was the first time otoliths were used to estimate daily age, growth, and hatching date for M. albus, which can be useful for understanding the ecology of this species in the wild.

Stratigraphic and interregional changes in Pennsylvanian coal-swamp vegetation: Environmental inferences

USGS Publications Warehouse

Phillips, T.L.; Peppers, R.A.; DiMichele, W.A.

1985-01-01

Quantitative analysis of Pennsylvanian coal-swamp vegetation provides a means of inferring organization and structure of communities. Distribution of these communities further provides inferences about environmental factors, including paleoclimate. Our observations are based on in situ, structurally preserved peat deposits in coal-ball concretions from 32 coal seams in the eastern one-half of the United States and from several seams in western Europe and on spore assemblages from more than 150 seams. There were three times of particularly significant and nearly synchronous vegetational changes in the Midcontinent and Appalachian coal regions during the Pennsylvanian Period. Each was different in kind and magnitude. The first marked changes occurred during the early part of the Middle Pennsylvanian with the fluctuating decline in the high level of lycopod dominance. The abundance of cordaites increased. There was a rise in the occurrences of the lycopod herbs to form intercalated marshlands and an overall increase in floral diversity. Changes ensuing from this time also include shifts in dominant species of lycopod trees and a sustained rise in abundance and diversity of tree-fern spores. The next significant time of change was during the middle part of the Middle Pennsylvanian, representing both a culmination of earlier trends and expansions of cordaites in the Midcontinent where there was a maximum change in species without net loss of diversity. Tree ferns and medullosan pteridosperms attained subdominant levels of abundance and diverse lycopod species dominated except in the Atokan-Desmoinesian transition of the Midcontinent. The third and sharpest break occurred near the Middle-Late Pennsylvanian boundary when extinctionsof the dominant, coal-swamp lycopods allowed development of tree-fern dominance. The Late Pennsylvanian coal swamps apparently were colonized or recolonized mainly by species from outside coal swamps rather than by the survivor populations of the Middle Pennsylvanian swamps. Paralleling the changes in floras through the Pennsylvanian are changes in preservational aspects of the peat. These include a decline in shoot/root ratios from approximately 1 to < 1 during the first time of vegetational changes and a rise in this ratio during the second; there was a parallel rise and fall in fusain abundance and a rise in wood/periderm ratios. The stratigraphic distribution of identified coal resources in the United States is interpreted as largely dependent on net changes in relative wetness of Pennsylvanian coal swamps, a pattern of drying during the first period of vegetational change, followed by a concomitant increase in continuous wet climate with brackish influence in the Midcontinent during the second; this was followed by a time of extreme moisture stress bringing on the third, and most severe, vegetational change. ?? 1986.

Alternative Penetrometers to Measure the Near Surface Strength of Soft Seafloor Soils

DTIC Science & Technology

2011-09-30

penetrometer (CPT), standard ball penetrometer (BPT), mini-ball penetrometer (mBPT) and a shear vane ( VST ). The CPT and BPT measure electronically a...The VST records the undrained shear strength of the soil at discreet depths. In addition, Shelby tube samples were collected for triaxial and...benchmark strengths from the VST and triaxial/simple shear tests. Thus far, the VST strengths have compared favorably with the results. Results from the

Analysis of aggregate pier systems for stabilization of subgrade settlement.

DOT National Transportation Integrated Search

2014-12-01

Every year, ODOT undertakes numerous pavement patching/resurfacing projects to repair pavement : distress and structural failure due to soft and/or organic soils constituting the subgrade. Other than the : temporary solution of patching/resurfacing, ...

Quality assessment of geogrids used for subgrade treatment.

DOT National Transportation Integrated Search

2012-12-01

Geogrid reinforcements have been used by the Indiana Department of Transportation (INDOT) to construct stable subgrade foundations : and to provide a working platform for construction over weak and soft soils. Use of geogrid reinforcement in a paveme...

Robotic Mining Competition - Awards Ceremony

NASA Image and Video Library

2018-05-18

NASA's 9th Annual Robotic Mining Competition concludes with an awards ceremony May 18, 2018, at the Apollo/Saturn V Center at the Kennedy Space Center Visitor Complex in Florida. The University of Alabama Team Astrobotics received the Efficient Use of Communications Power Award. At left is retired NASA astronaut Jerry Ross. At right is Kurt Leucht, a NASA engineer in Swamp Works and event emcee. More than 40 student teams from colleges and universities around the U.S. participated in the competition, May 14-18, by using their mining robots to dig in a supersized sandbox filled with BP-1, or simulated lunar soil, gravel and rocks, and participate in other competition requirements. The Robotic Mining Competition is a NASA Human Exploration and Operations Mission Directorate project designed to encourage students in science, technology, engineering and math, or STEM fields. The project provides a competitive environment to foster innovative ideas and solutions that could be used on NASA's deep space missions.

Earth Observations taken by the Expedition 39 Crew

NASA Image and Video Library

2014-05-09

ISS039-E-019482 (9 May 2014) --- One of the Expedition 39 crew members aboard the Earth-orbiting International Space Station used a 400mm lens to take this photograph of Venice Lagoon, Italy on May 9, 2014. A narrow barrier island protects the Lagoon of Venice from storm waves in the northern Adriatic Sea, and breakwaters protect inlets to the lagoon. Red tiles of the roofs of the edifices on the island of Venice contrast with the grays of the mainland sister city of Mestre. The cities are joined by a prominent causeway. Another causeway joins the island to the airport (top right). Small bright agricultural fields of well drained soils (top left) contrast with the darker vegetation of back bay swamps where fishing is a popular pastime. Dense urban populations on its shores and heavy use by craft of all kinds result in turbid water in the northern half of the lagoon.

Removal of organic matter and electricity generation of sediments from Progreso, Yucatan, Mexico, in a sediment microbial fuel cell.

PubMed

González-Gamboa, Nancy Karina; Valdés-Lozano, David Sergio; Barahona-Pérez, Luis Felipe; Alzate-Gaviria, Liliana; Domínguez-Maldonado, Jorge Arturo

2017-02-01

Sediment microbial fuel cells (SMFCs) are devices that generate electrical energy through sediments rich in organic matter (OM). The present study assessed the potential of sediments collected at two sites in Yucatan, Mexico, (the swamp of Progreso port and Yucalpetén dock) to be used in these electrochemical devices. Sediments were collected during the rainy and winter seasons and were monitored in the SMFC for 120 days through electrochemical and physicochemical characterization. OM removal in the SMFC ranged from 8.1-18.01%, generating a maximum current density of 232.46 mA/cm 2 and power density of 95.85 mW/cm 2 . SUVA analysis indicated that with a young soil, the ratio E4/E6 presented evidence directly related to the degradation of aromatic and aliphatic compound formation, implying humification and, therefore, sediment enrichment.

Degradation of Malaysian peatlands decreases levels of phenolics in soil and in leaves of Macaranga pruinosa

NASA Astrophysics Data System (ADS)

Yule, Catherine; Lim, Yau; Lim, Tse

2016-04-01

Indo-Malaysian tropical peat swamp forests (PSF) sequester enormous stores of carbon in the form of phenolic compounds, particularly lignin as well as tannins. These phenolic compounds are crucial for ecosystem functioning in PSF through their inter-related roles in peat formation and plant defenses. Disturbance of PSF causes destruction of the peat substrate, but the specific impact of disturbance on phenolic compounds in peat and its associated vegetation has not previously been examined. A scale was developed to score peatland degradation based on the three major human impacts that affect tropical PSF - logging, drainage and fire. The objectives of this study were to compare the amount of phenolic compounds in Macaranga pruinosa, a common PSF tree, and in the peat substrate along a gradient of peatland degradation from pristine peat swamp forest to cleared, drained and burnt peatlands. We examined phenolic compounds in M. pruinosa and in peat and found that levels of total phenolic compounds and total tannins decrease in the leaves of M.pruinosa and also in the surface peat layers with an increase in peatland degradation. We conclude that waterlogged conditions preserve the concentration of phenolic compounds in peat, and that even PSF that has been previously logged but which has recovered a full canopy cover will have high levels of total phenolic content (TPC) in peat. High levels of TPC in peat and in the flora are vital for the inhibition of decomposition of organic matter and this is crucial for the accretion of peat and the sequestration of carbon. Thus regional PSF flourish despite the phenolic rich, toxic, waterlogged, nutrient poor, conditions, and reversal of such conditions is a sign of degradation.

Mercury methylation in forested uplands; how important is it?

NASA Astrophysics Data System (ADS)

Shanley, J. B.; Marvin-Dipasquale, M.; Schuster, P. F.; Chalmers, A.; Reddy, M. M.

2004-05-01

Episodic fluxes of mercury during high flows at the headwater catchment at the Sleepers River Research Watershed in Vermont indicate that uplands are an important source of total mercury (Hg) to known downstream methylation sites (i.e. large wetlands). Methylmercury (MeHg) behavior in streamwater, soil water, and sediment porewater coupled with high potential methylation rates suggests that forested uplands may be significant source areas for MeHg as well. In a July 2003 incubation, potential Hg methylation rates exceeded potential demethylation rates by factors of 1.6 each in shallow (0-4 cm) swamp and riparian soils and by 19.6 in anoxic stream sediments. The stream sediment had the greatest methylation rate of 7.5 ng/ g of wet sediment / day. However, MeHg concentrations in filtered (0.4 um) porewater at these sites ranged only from 0.07 to 0.37 ng/ L, similar to the range at low-lying wetland sites elsewhere in Vermont (0.06 to 0.56 ng/L). In Sleepers River headwaters as well as larger Vermont rivers, most of the MeHg export occurs during snowmelt and summer / fall storms, with nearly all of the MeHg occurring in the particulate phase. Stream total Hg and MeHg concentrations were consistently correlated, suggesting a common source, probably soil organic matter. The methylation efficiency (ratio MeHg / total Hg) was near 2% in the Sleepers River headwaters, similar to that in Vermont rivers draining large wetland systems, indicating that the methylation process originates in the headwaters.

Tonawanda Creek, Genesee County, New York, Regional Flood Control. Final Environmental Impact Statement.

DTIC Science & Technology

1981-11-01

sedges, rushes, cattails, and iris and some woody shrub species, have established within or around the periphery of these areas that help to pro- vide...extensively in spring and fall. Shrub swamps are comprised of woody species such as red-osier dogwood, silky dogwood, arrow-wood, buckthorn, slippery...valuable to wildlife and are used extensively by migrating waterfowl during the spring and summer. Shrub swamps are dominated by woody species, including

Evaluation of environmental magnetic pollution screening in soils of basaltic origin: results from Nashik Thermal Power Station, Maharashtra, India.

PubMed

Basavaiah, N; Blaha, U; Das, P K; Deenadayalan, K; Sadashiv, M B; Schulz, H

2011-08-01

Soils of basaltic origin cause difficulties in environmental magnetic screening for heavy metal pollution due to their natural high background values. Magnetic parameters and heavy metal content of highly magnetic topsoils from the Deccan Trap basalts are investigated to assess their potential for use in environmental magnetic pollution screening. This work extends the fast and cost-effective magnetic pollution screening techniques into soils with high natural magnetic signals. Fifty-five topsoil samples from N-S and W-E transects were collected and subdivided according to grain size using wet sieving technique. Magnetic susceptibility, soft isothermal remanent magnetization (Soft IRM), thermomagnetic analysis, scanning electron microscopy (SEM), and heavy metal analysis were performed on the samples. Magnetic analyses reveal a significant input of anthropogenic magnetic particulate matter within 6 km of the power plant and the adjacent ash pond. Results depend strongly on the stage of soil development and vary spatially. While results in the W, E, and S directions are easily interpretable, in the N direction, the contribution of the anthropogenic magnetic matter is difficult to assess due to high magnetic background values, less developed soils, and a more limited contribution from the fly ash sources. Prevailing winds towards directions with more enhanced values seem to have a certain effect on particulate matter accumulation in the topsoil. Thermomagnetic measurements show Verwey transition and Hopkinson peak, thus proving the presence of ferrimagnetic mineral phases close to the pollution source. A quantitative decrease of the anthropogenic ferrimagnetic mineral concentration with increased distance is evident in Soft IRM measurements. SEM investigations of quantitatively extracted magnetic particles confirm the fly ash distribution pattern obtained from the magnetic and heavy metal analyses. Evaluation of magnetic and chemical data in concert with the Pollution Load IndiceS (PLIS) of Pb, Zn, and Cu reveals a good relationship between magnetic susceptibility and the metal content. Integrated approaches in data acquisition of magnetic and chemical parameters enable the application of magnetic screening methods in highly magnetic soils. Combined data evaluation allows identification of sampling sites that are affected by human activity, through the deviation of the magnetic and chemical data from the general trend. It is shown that integrative analysis of magnetic parameters and a limited metal concentration dataset can enhance the quality of the output of environmental magnetic pollution screening significantly.

Along-Arc and Back-Arc Attenuation, Site Response, and Source Spectrum for the Intermediate-Depth 8 January 2006 M 6.7 Kythera, Greece, Earthquake

USGS Publications Warehouse

Boore, David M.; Skarlatoudis, A.A.; Margaris, B.N.; Costas, B.P.; Ventouzi, C.

2009-01-01

An M 6.7 intermediate-depth (66 km), in-slab earthquake occurring near the island of Kythera in Greece on 8 January 2006 was well recorded on networks of stations equipped with acceleration sensors and with broadband velocity sensors. All data were recorded digitally using recording instruments with resolutions ranging from almost 11 to 24 bits. We use data from these networks to study the distance dependence of the horizontal-component Fourier acceleration spectra (FAS) and horizontal-component pseudoabsolute response spectral acceleration (PSA). For purposes of simulating motions in the future, we parameterize the distance decay using several forms of the geometrical-spreading function, for each of which we derive Q as a function of frequency. By extrapolating the distance decay back to 1 km, we obtain a reference spectrum that can be used in future simulations. This spectrum requires a more complicated spectral shape than the classic single-corner-frequency model; in particular, there appears to be an enhancement of motion around 0.2-0.3 Hz that may be due to the radiation of a 3-5 sec pulse from the source. We infer a ??0 value of about 0.055 sec for rock stations and a stress parameter in the range of 400-600 bars. We also find distinctive differences in the site response of stations on soft soil and soil; both the FAS and the 5% damped PSA amplifications have similar peak amplitudes (about 2 and 4 for soil and soft-soil sites, respectively, relative to the rock sites) at similar frequencies (between about 0.4 and 2.0 Hz, with the soft-soil amplifications peaking at somewhat lower frequencies than the soil amplifications). One of the most distinctive features of the data is the clear difference in the motions for along-arc and back-arc stations, with the former being significantly higher than the latter over a broad range of frequencies at distances beyond about 250 km. The motions from the Kythera earthquake are roughly comparable to those from intermediate-depth earthquakes elsewhere, but they appear to be significantly higher than those from recordings of shallow earthquakes in Greece of comparable magnitude and hypocentral distance.

Relationships between Vacant Homes and Food Swamps: A Longitudinal Study of an Urban Food Environment.

PubMed

Mui, Yeeli; Jones-Smith, Jessica C; Thornton, Rachel L J; Pollack Porter, Keshia; Gittelsohn, Joel

2017-11-21

Research indicates that living in neighborhoods with high concentrations of boarded-up vacant homes is associated with premature mortality due to cancer and diabetes, but the mechanism for this relationship is unclear. Boarded-up housing may indirectly impact residents' health by affecting their food environment. We evaluated the association between changes in vacancy rates and changes in the density of unhealthy food outlets as a proportion of all food outlets, termed the food swamp index, in Baltimore, MD (USA) from 2001 to 2012, using neighborhood fixed-effects linear regression models. Over the study period, the average food swamp index increased from 93.5 to 95.3 percentage points across all neighborhoods. Among non-African American neighborhoods, increases in the vacancy rate were associated with statistically significant decreases in the food swamp index (b = -0.38; 90% CI, -0.64 to -0.12; p -value: 0.015), after accounting for changes in neighborhood SES, racial diversity, and population size. A positive association was found among low-SES neighborhoods (b = 0.15; 90% CI, 0.037 to 0.27; p -value: 0.031). Vacant homes may influence the composition of food outlets in urban neighborhoods. Future research should further elucidate the mechanisms by which more distal, contextual factors, such as boarded-up vacant homes, may affect food choices and diet-related health outcomes.

Relationships between Vacant Homes and Food Swamps: A Longitudinal Study of an Urban Food Environment

PubMed Central

Mui, Yeeli; Jones-Smith, Jessica C.; Thornton, Rachel L. J.; Pollack Porter, Keshia; Gittelsohn, Joel

2017-01-01

Research indicates that living in neighborhoods with high concentrations of boarded-up vacant homes is associated with premature mortality due to cancer and diabetes, but the mechanism for this relationship is unclear. Boarded-up housing may indirectly impact residents’ health by affecting their food environment. We evaluated the association between changes in vacancy rates and changes in the density of unhealthy food outlets as a proportion of all food outlets, termed the food swamp index, in Baltimore, MD (USA) from 2001 to 2012, using neighborhood fixed-effects linear regression models. Over the study period, the average food swamp index increased from 93.5 to 95.3 percentage points across all neighborhoods. Among non-African American neighborhoods, increases in the vacancy rate were associated with statistically significant decreases in the food swamp index (b = −0.38; 90% CI, −0.64 to −0.12; p-value: 0.015), after accounting for changes in neighborhood SES, racial diversity, and population size. A positive association was found among low-SES neighborhoods (b = 0.15; 90% CI, 0.037 to 0.27; p-value: 0.031). Vacant homes may influence the composition of food outlets in urban neighborhoods. Future research should further elucidate the mechanisms by which more distal, contextual factors, such as boarded-up vacant homes, may affect food choices and diet-related health outcomes. PMID:29160811

Profiling Groundwater Salt Concentrations in Mangrove Swamps and Tropical Salt Flats

NASA Astrophysics Data System (ADS)

Ridd, Peter V.; Sam, Renagi

1996-11-01

The salt concentration of groundwater in mangrove swamps is an important parameter controlling the growth of mangrove species. Extremely high salt concentrations of groundwater in tropical salt flats are responsible for the complete absence of macrophytes. Determining groundwater salt concentrations can be a very time-consuming and laborious process if conventional techniques are used. Typically, groundwater samples must be extracted for later laboratory analysis. In this work, a simple conductivity probe has been developed which may be inserted easily to a depth of 2 m into the sediment. The changes in conductivity of the sediment is due primarily to porewater salt concentration, and thus ground conductivity is useful in determining changes in groundwater salt concentrations. Using the conductivity probe, transects of sediment conductivity can be undertaken quickly. As an example of a possible application of the probe, transects of ground conductivity were taken on a mangrove swamp/saltflat system. The transects show clearly the sharp delineation in conductivity between the salt flat and mangrove swamp due to a change in groundwater salt concentrations. Horizontal and vertical salt concentration gradients of up to 50 g l -1 m -1and 150 g l -1 m -1, respectively, were found. Very sharp changes in groundwater salt concentrations at the interface between salt flats and mangroves indicate that the mangroves may be modifying the salinity of the groundwater actively.

Second Test Rover Added for Free Spirit Tests

NASA Image and Video Library

2009-08-21

Testing at NASA Jet Propulsion Laboratory in August 2009 is assessing possible maneuvers that the Mars rover Spirit might use for escaping from a patch of soft soil where it is embedded at a Martian site called Troy.

Hydropedological model of vertisol formation along the Gulf Coast Prairie land resource area of Texas

NASA Astrophysics Data System (ADS)

Nordt, L. C.; Driese, S. G.

2009-11-01

Vertisols are clayey soils containing slickensides and wedge-shaped aggregates formed by shrink-swell processes in seasonally wet climates. The dynamic distribution of macro- and microvoids as a by-product of this unique pedoturbation process, accompanied by microtopographic lows and highs (gilgai), mitigate our ability to make accurate and precise interpretations of aquic and hydric conditions in these problem soils. We studied Vertisols across a subhumid to humid climosequence to assess the formation of redoximorphic features on shallow, linear (nondepressional) landscape positions in response to varying levels of rainfall. Approximately 1000 mm of mean annual precipitation (MAP) is required to form soft iron masses that then increase in abundance, and to shallower depths, with increasing rainfall. Soft iron masses with diffuse boundaries become more abundant with higher rainfall in microlows, whereas masses with nondiffuse boundaries become more common in microhighs. Most soft iron masses form in oxygenated ped interiors as water first saturates and then reduces void walls where iron depletions form. In contrast, at least 1276 mm of MAP is needed to form iron pore linings in both microlow and microhigh topographic positions. Iron depletions do not correlate with rainfall in terms of abundance or depth of occurrence. The quantity of crayfish burrows co-varies with rainfall and first appears coincidentally with soft iron masses in microlows near 1000 mm of MAP; they do not appear until nearly 1400 mm of MAP in microhighs. Dithionite-citrate extractable and ammonium-oxalate extractable iron oxides increase systematically with rainfall indicating more frequent episodes of iron reduction and precipitation into pedogenic segregations. The sum of our data suggests that Vertisols forming in the Coast Prairie of Texas with MAP greater than 1276 mm should be classified as aquerts because of the presence of aquic conditions. These same soils may also meet the definition of hydric as one criterion for the identification of Federally-protected wetlands. However, there is a considerable disjunct between protracted periods of saturation and limited periods of reduction in these soils. Based on the distribution of redoximorphic features in the study area, regional water table data, and recent electrical resistivity data from a nearby upland Vertisol, non-Darcian bypass flow is the principle mechanism governing the flux of water through deep cracks where water first accumulates and then persists in microlow bowls at depths of 1 to 2 m.

Evaluation of the Applicability of Environmental Magnetic Pollution Screening in Soils of Basaltic Origin: Results from Nashik Thermal Power Station, Maharashtra, India

NASA Astrophysics Data System (ADS)

Blaha, U.; Nathani, B.; Das, P. K.; Kannan, D.

2011-12-01

Magnetic parameters and heavy metal contents of highly magnetic topsoil of the Deccan Trap basalt region were investigated for their potential to be used for environmental magnetic pollution screening. Data of magnetic susceptibility (χ) and soft isothermal remanent magnetization (Soft IRM) of 55 soil samples from N-S and W-E transects reveal a significant input of anthropogenic magnetic particulate matter within a range of 6 km around both the coal fired power plant and its adjacent ash pond. Less developed and thin topsoil layers as well as limited contribution from the fly ash sources in N direction pose difficulties for unambiguous assessment of the magnetic parameters. Heavy metal data, i.e. Pb, Zn and Cu concentrations of the soil grain size of <63 μm reveal similar distribution patterns as obtained from the magnetic parameters of all directions. Fluctuations are observed in magnetic as well as in heavy metal data and are primarily attributed to soil development. Thermo-magnetic measurements identify magnetite of anthropogenic origin in the vicinity of the pollution source based on Verwey-Transition and Hopkinson peak. The quantitative decrease of the anthropogenic ferrimagnetic mineral concentration with distance is proven by Soft IRM. Confirmation of the presence of extremely high and low amounts of ash particles in the magnetically and chemically distinguished zones is provided by scanning electron microscopy (SEM) on quantitatively extracted magnetic particles at 5.5 km and 11.9 km distance. Evaluation of magnetic and chemical data including pollution load indices (PLIS) of Pb, Zn and Cu reveals good relationship of χ with the metal contents. The highest of the PLIS for Pb, Zn and Cu reveals threefold enhancement of concentration with respect to the natural background at 12 km distance and is obtained close to the fly ash sources.

Procedures for One-Pass Vehicle Cone Index (VCI1) Determination for Acquisition Support

DTIC Science & Technology

2013-08-01

the VCI of tracked vehicles can be directly compared to that of wheeled vehicles; Priddy and Willoughby, 2006). Measurement of the minimum soil...of the wheel , or number of revolutions per unit time divided by 2π for a track v = forward velocity of vehicle or wheel axle. 12. Trafficability...be tested at the expected gross vehicle weight (GVW) and, for wheeled vehicles, at an appropriate soft-soil tire pressure. For wheeled vehicles

Linking river, floodplain, and vadose zone hydrology to improve restoration of a coastal river affected by saltwater intrusion.

PubMed

Kaplan, D; Muñoz-Carpena, R; Wan, Y; Hedgepeth, M; Zheng, F; Roberts, R; Rossmanith, R

2010-01-01

Floodplain forests provide unique ecological structure and function, which are often degraded or lost when watershed hydrology is modified. Restoration of damaged ecosystems requires an understanding of surface water, groundwater, and vadose (unsaturated) zone hydrology in the floodplain. Soil moisture and porewater salinity are of particular importance for seed germination and seedling survival in systems affected by saltwater intrusion but are difficult to monitor and often overlooked. This study contributes to the understanding of floodplain hydrology in one of the last bald cypress [Taxodium distichum (L.) Rich.] floodplain swamps in southeast Florida. We investigated soil moisture and porewater salinity dynamics in the floodplain of the Loxahatchee River, where reduced freshwater flow has led to saltwater intrusion and a transition to salt-tolerant, mangrove-dominated communities. Twenty-four dielectric probes measuring soil moisture and porewater salinity every 30 min were installed along two transects-one in an upstream, freshwater location and one in a downstream tidal area. Complemented by surface water, groundwater, and meteorological data, these unique 4-yr datasets quantified the spatial variability and temporal dynamics of vadose zone hydrology. Results showed that soil moisture can be closely predicted based on river stage and topographic elevation (overall Nash-Sutcliffe coefficient of efficiency = 0.83). Porewater salinity rarely exceeded tolerance thresholds (0.3125 S m(-1)) for bald cypress upstream but did so in some downstream areas. This provided an explanation for observed vegetation changes that both surface water and groundwater salinity failed to explain. The results offer a methodological and analytical framework for floodplain monitoring in locations where restoration success depends on vadose zone hydrology and provide relationships for evaluating proposed restoration and management scenarios for the Loxahatchee River.

Thermal Conductivity Prediction of Soil in Complex Plant Soil System using Artificial Neural Networks

NASA Astrophysics Data System (ADS)

Wardani, A. K.; Purqon, A.

2016-08-01

Thermal conductivity is one of thermal properties of soil in seed germination and plants growth. Different soil types have different thermal conductivity. One of soft-computing promising method to predict thermal conductivity of soil types is Artificial Neural Network (ANN). In this study, we estimate the thermal conductivity of soil prediction in a soil-plant complex systems using ANN. With a feed-forward multilayer trained with back-propagation with 4, 10 and 1 on the input, hidden and output layers respectively. Our input are heating time, temperature and thermal resistance with thermal conductivity of soil as a target. ANN prediction demonstrates a good agreement with Mean Squared Error-testing (MSEte) of 9.56 x 10-7 for soils with green beans and those of bare soils is 7.00 × 10-7 respectively Green beans grow only on black-clay soil with a thermal conductivity of 0.7 W/m K with a sufficient water content. Our results demonstrate that temperature, moisture content, colour, texture and structure of soil are greatly affect to the thermal conductivity of soil in seed germination and plant growth. In future, it is potentially applied to estimate more complex compositions of plant-soil systems.

Functional traits of soil invertebrates as indicators for exposure to soil disturbance.

PubMed

Hedde, Mickaël; van Oort, Folkert; Lamy, Isabelle

2012-05-01

We tested a trait-based approach to link a soil disturbance to changes in invertebrate communities. Soils and macro-invertebrates were sampled in sandy soils contaminated by long-term wastewater irrigation, adding notably organic matter and trace metals (TM). We hypothesized that functional traits of invertebrates depict ways of exposure and that exposure routes relate to specific TM pools. Geophages and soft-body invertebrates were chosen to inform on exposure by ingestion or contact, respectively. Trait-based indices depicted more accurately effects of pollution than community density and diversity did. Exposure by ingestion had more deleterious effects than by contact. Both types of exposed invertebrates were influenced by TM, but geophages mainly responded to changes in soil organic matter contents. The trait-based approach requires to be applied in various conditions to uncorrelate specific TM impacts from those of other environmental factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

Accelerated loading evaluation of subbase layers in pavement performance : tech summary.

DOT National Transportation Integrated Search

2009-04-01

The mighty Mississippi River formed and sculpted most of south Louisiana, creating large areas of alluvial : deposits consisting of soft, wet, and unconsolidated soil layers. Many Louisiana pavements were built in : these areas of naturally low shear...

Integral abutment bridge for Louisiana's soft and stiff soils.

DOT National Transportation Integrated Search

2016-03-01

Integral abutment bridges (IABs) have been designed and constructed in a few US states in the past few : decades. The initial purpose of building such bridges was to eliminate the expansion joints and resolve the : joint-induced problems. Although IA...

Proceedings of the National Wetland Symposium: Wetland Hydrology Held in Chicago, Illinois on September 16-18 1987

DTIC Science & Technology

1987-09-16

the leached sand at both outcrops. Woody wetland vegetation in the form of a shrub swamp or a wooded swamp, as suggested The leached sand overlies...till vertical feet of woody moss peat was deposited that is more friable and reddish brown in color either by the persistence of a shrub or wooded...important and the dominant typically marshes, replacing many shrub and source of water for wetlands located on river forested wetlands slopes or

A new dwarf crayfish (Decapoda: Cambaridae) from floodplain swamps in central Alabama.

PubMed

Schuster, Guenter A; Kendrick, Michael R

2017-03-05

Cambarellus (Pandicambarus) rotatus, new species, is a dwarf crayfish from floodplain swamps in the Tombigbee and Black Warrior river drainages of Greene, Hale, and Marengo counties, Alabama. The new species is morphologically most similar to Cambarellus (Pandicambarus) lesliei. They differ in a several morphological characters. Cambarellus rotatus, new species, has gonopods that are rotated mesially so that the terminal elements oppose each other, and they have a short C-shaped sperm groove. These are unique features among known species of Cambarellus.

Peat in modern swamps mimics coal origins 300 M years ago

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

Given, P.H.; Ryan, N.J.; Rhoads, C.A.

1985-07-01

Peat swamps can provide excellent models of ancient coal-forming processes. Peats of differing salinity and vegetational cover exhibit different trends of chemistry with depth, which have been studied in order to clarify ideas of coal origins. Thus changes with depth of phenolic structures determined by pyrolysis/gas chromatography/mass spectrometry reflect changes in plant source and partial microbial degradation of lignin, which will be reflected in the structure of coals that may form later. 12 refs., 3 figs.

CBR Operations in Cold Weather: A Bibliography. Volume 1

DTIC Science & Technology

1989-11-01

JOHNSTON R C SWAMP OAK TEST DATA DOD/DROLS ; HANNEMANN M M D ANALYSIS. 514727L ;HALLANGER N L ;KROTH J R ;WESTLAKE WILFRED J ; HAMILTON WILLIAM M 1953...E 1963 HANNA ALFRED E; SIMULATED COLD WEATHER DOD/DROLS RADIOLOGICAL DECONTAMINATION 296248 OF RECOVERY EQUIPMENT. HANNEMANN M M D 1967 JOHNSTON R C...SWAMP OAK TEST DATA DOD/DROLS ; HANNEMANN M M D ANALYSIS. 514727L ;HALLANGER N L ;KROTH J R ;WESTLAKE WILFRED J : 37 HELLBERG E N 1961 TAYLOR D

Paleobotany and palynology of the Bristol Hill Coal Member (Bond Formation) and Friendsville Coal Member (Mattoon Formation) of the Illinois Basin (Upper Pennsylvanian)

USGS Publications Warehouse

Willard, D.A.; Phillips, T.L.

1993-01-01

Late Pennsylvanian coal swamps of the Illinois Basin were dominated by Psarnius tree ferns with a spatially heterogeneous distribution of medullosan pteridosperms (subdominant), calamites, sigillarian lycopsids, and cordaites. Miospore and coal-ball plant assemblages from the Missourian-age Bristol Hill Coal Member (Mattoon Formation) of southeastern Illinois were quantified to analyze vegetational patterns in Late Pennsylvanian peat swamps and to compare vegetational composition of the coals. -from Authors

Soil sampling kit and a method of sampling therewith

DOEpatents

Thompson, Cyril V.

1991-01-01

A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allow an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds.

Soil sampling kit and a method of sampling therewith

DOEpatents

Thompson, C.V.

1991-02-05

A soil sampling device and a sample containment device for containing a soil sample is disclosed. In addition, a method for taking a soil sample using the soil sampling device and soil sample containment device to minimize the loss of any volatile organic compounds contained in the soil sample prior to analysis is disclosed. The soil sampling device comprises two close fitting, longitudinal tubular members of suitable length, the inner tube having the outward end closed. With the inner closed tube withdrawn a selected distance, the outer tube can be inserted into the ground or other similar soft material to withdraw a sample of material for examination. The inner closed end tube controls the volume of the sample taken and also serves to eject the sample. The soil sample containment device has a sealing member which is adapted to attach to an analytical apparatus which analyzes the volatile organic compounds contained in the sample. The soil sampling device in combination with the soil sample containment device allows an operator to obtain a soil sample containing volatile organic compounds and minimizing the loss of the volatile organic compounds prior to analysis of the soil sample for the volatile organic compounds. 11 figures.

Operational restoration of the Pen Branch bottomland hardwood and swamp wetlands - the research setting

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

Nelson, E.A.

2000-01-05

The Savannah River Swamp is a 3020 Ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy's Savannah River Site (SRS) near Aiken, SC. Historically the swamp consisted of approximately 50 percent bald cypress-water tupelo stands, 40 percent mixed bottomland hardwood stands, and 10 percent shrub, marsh, and open water. Creek corridors were typical of Southeastern bottomland hardwood forests. The hydrology was controlled by flooding of the Savannah River and by flow from four creeks that drain into the swamp prior to flow into the Savannah River. Upstream dams have caused somemore » alteration of the water levels and timing of flooding within the floodplain. Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950's. Water was pumped from the Savannah River, through secondary heat exchangers of the reactors, and discharged into three of the tributary streams that flow into the swamp. Flow in one of the tributaries, Pen Branch, was typically 0.3 m3 s-1 (10-20) cfs prior to reactor pumping and 11.0 m3 s-1 (400 cfs) during pumping. This continued from 1954 to 1988 at various levels. The sustained increases in water volume resulted in overflow of the original stream banks and the creation of additional floodplains. Accompanying this was considerable erosion of the original stream corridor and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 65 degrees C. The nearly continuous flooding of the swamp, the thermal load of the water, and the heavy silting resulted in complete mortality of the original vegetation in large areas of the floodplain. In the years since pumping was reduced, early succession has begun in some affected areas. Most of this has been herbs, grasses, and shrubs. Areas that have seedlings are generally willow thickets that support a lower diversity of wildlife. No volunteer seedlings of heavy-seeded hardwoods or cypress have been found in the corridor areas. Research was conducted to determine methods to reintroduce tree species characteristic of more mature forested wetlands. Three restoration strategies were formulated to deal with the differing conditions of the Upper Corridor, the Lower Corridor, and the Delta regions of the impacted area. Site preparation and planting of each area with mixtures of tree species were carried out to speed the restoration of the ecosystem. Species composition and selection were altered based on the current and expected hydrological regimes that the reforestation areas will be experiencing. Because of the operational design of the restoration project, a research program naturally followed to document the success. Many of those efforts are detailed here.« less

1-D Compression Behaviour of Acid Sulphate Soils Treated with Alkali-Activated Slag

PubMed Central

Islam, Shahidul; Haque, Asadul; Bui, Ha Hong

2016-01-01

Improvements of soft soils by mechanically mixing cementitious additives have been widely practised for construction of infrastructure. Mixing of additives improves strength and compressibility properties of soils through the development of soil structure. This study investigates the 1-D compression behaviour of alkali-activated slag treated acid sulphate soils (ASS) cured up to 365 days. The void ratio-logarithm of pressure (e-logσ′) behaviour of treated ASS, including the destructuration behaviour, with additive contents and curing time have been analysed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses have been undertaken to explain the observed variations of the 1-D compression behaviour. This paper presents the results of these analyses in view of obtaining an insight into the 1-D compression behaviour of treated ASS with the help of mineralogical analysis. PMID:28773415

1-D Compression Behaviour of Acid Sulphate Soils Treated with Alkali-Activated Slag.

PubMed

Islam, Shahidul; Haque, Asadul; Bui, Ha Hong

2016-04-15

Improvements of soft soils by mechanically mixing cementitious additives have been widely practised for construction of infrastructure. Mixing of additives improves strength and compressibility properties of soils through the development of soil structure. This study investigates the 1-D compression behaviour of alkali-activated slag treated acid sulphate soils (ASS) cured up to 365 days. The void ratio-logarithm of pressure (e-logσ') behaviour of treated ASS, including the destructuration behaviour, with additive contents and curing time have been analysed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses have been undertaken to explain the observed variations of the 1-D compression behaviour. This paper presents the results of these analyses in view of obtaining an insight into the 1-D compression behaviour of treated ASS with the help of mineralogical analysis.

Selenium in particulates and gaseous fractions of smoke from cigarettes prepared from tobacco grown on fly-ash-amended soil

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

Gutemann, W.H.; Lisk, D.J.; Hoffman, D.

Cigarettes prepared from tobacco grown in pots of soils amended with soft coal fly ash were smoked, and the mainstream and gaseous fractions were analyzed for total selenium concentration. Fly-ash-grown and control (soil-grown) tobaccos contained, respectively, 0.79 and 0.03 ppm selenium. The quantities of selenium (ng per cigarette) found in the mainstream particulate and gaseous fractions were, respectively, 62.4 and 246.0 for the fly-ash-grown and 8.6 and 12.0 for the control treatments. Studies of the absorption, retention, effects, metabolism, and excretion of selenium in the body are reviewed.

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

Naqvi, S.M.; Howell, R.D.; Sholas, M.

The whole-body residues of Cd and Pb in the tissues of Louisiana swamp crayfish (Procambarus clarkii) were determined by flame AAS technique. Test animals were collected from roadside ditches alongside major highways. The water and soil samples were also collected from the same sites. The mean Cd and Pb concentrations in crayfish tissues were 0.46 and 0.07, respectively. The levels of Cd and Pb in the water were 0.09 and 0.04; and in soil were 2.85 and 0.87 mg/1, respectively. The concentration of cadmium was 32 and Pb 12 times more than in the water. The bioaccumulation factors (BF) formore » Cd and Pb in crayfish tissues were 5.1 and 1.7, respectively. Alligator weed (Alternanthera philoxiroides) plants were exposed to 0.5 mg/1 Cd-chloride or Pb-nitrate solutions for 3 wk period, thrice. The mean Pb accumulation in roots was 1.31 mg/1, followed by stem (0.078 mg/1), but Cd only accumulated in root (0.83 mg/1). The BF for Pb and Cd in plant tissues were 14.8 and 16.6, respectively. The uptake of metals was time-dependent. These data suggest that although there is no biomagnification of Cd and Pb from alligator weed to crayfish, both metals readily accumulate in field-collected crayfish and laboratory-exposed alligator weed.« less

Relationships between 222Rn dissolved in ground water supplies and indoor 222Rn concentrations in some Colorado front range houses

USGS Publications Warehouse

Folger, P.F.; Nyberg, P.; Wanty, R.B.; Poeter, E.

1994-01-01

Indoor 222Rn concentrations were measured in 37 houses with alpha track detectors placed in water-use rooms near water sources (bathrooms, laundry rooms, and kitchens) and in non-water-use living rooms, dining rooms, and bedrooms away from water sources. Results show that relative contributions of 222Rn to indoor air from water use are insignificant when soil-gas concentrations are high but become increasingly important as the ratio of 222Rn-in-water:222Rn-in-soil gas increases. High soil-gas 222Rn concentrations may mask 222Rn contributions from water even when waterborne 222Rn concentrations are as high as 750 kBq m-3. Ground water in Precambrian Pikes Peak granite averages 340 kBq m-3222Rn, vs. 170 kBq m-3 in Precambrian migmatite, but average 222Rn concentrations in soil gas are also lower in migmatite. Because the ratio of 222Rn-in- water:222Rn-in-soil gas may be consistently higher for houses in migmatite than in Pikes Peak granite, indoor air in houses built on migmatite may have a greater relative contribution from water use even though average 222Rn concentrations in the water are lower. Continuous monitoring of 222Rn concentrations in air on 15-min intervals also indicates that additions to indoor concentrations from water use are significant and measurable only when soil-gas concentrations are low and concentrations in water are high. When soil-gas concentrations were mitigated to less than 150 Bq m-3 in one house, water contributes 20-40% of the annual indoor 222Rn concentration in the laundry room (222Rn concentration in water of 670 kBq m-3). Conversely, when the mitigation system is inactive, diurnal fluctuations and other variations in the soil-gas 222Rn contribution swamp the variability due to water use in the house. Measurable variations in indoor concentrations from water use were not detected in one house despite a low soil-gas contribution of approximately 150 Bq m-3 because waterborne 222Rn concentrations also are low (80 kBq m-3). This result suggests that 222Rn concentrations in water near the recommended EPA limit in drinking water of 11 kBq m-3 may not contribute measurable amounts of 222Rn to indoor air in most houses.

Gnathostoma spinigerum in live Asian swamp eels (Monopterus spp.) from food markets and wild populations, United States

USGS Publications Warehouse

Cole, Rebecca A.; Choudhury, Anindo; Nico, Leo G.; Griffin, Kathryn M.

2014-01-01

In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 wild-caught specimens. Nematodes were identified by morphologic features and ribosomal intergenic transcribed spacer–2 gene sequencing. Thirteen (27.7%) M. cuchia eels from markets were infected with 36 live G. spinigerum AL3: 21 (58.3%) in liver; 7 (19.4%) in muscle; 5 (13.8%) in gastrointestinal tract, and 3 (8.3%) in kidneys. Three (4.5%) wild-caught M. albus eels were infected with 5 G. turgidum AL3 in muscle, and 1 G. lamothei AL3 was found in a kidney (both North American spp.). Imported live eels are a potential source of human gnathostomiasis in the United States.

Wetland Boundary Determination in the Great Dismal Swamp Using Weighted Averages

USGS Publications Warehouse

Carter, Virginia; Garrett, Mary Keith; Gammon, Patricia T.

1988-01-01

A weighted average method was used to analyze transition zone vegetation in the Great Dismal Swamp to determine if a more uniform determination of wetland boundaries can be made nationwide. The method was applied to vegetation data collected on four transects and three vertical layers across the wetland-to-upland transition zone of the swamp. Ecological index values based on water tolerance were either taken from the literature or derived from local species tolerances. Wetland index values were calculated for 25-m increments using species cover and rankings based on the ecological indices. Wetland index values were used to designate increments as either wetland, transitional, or upland, and to examine the usefulness of a provisional wetland-upland break-point. The weighted average method did not provide for an objective placement of an absolute wetland boundary, but did serve to focus attention on the transitional boundary zone where supplementary information is necessary to select a wetland-upland breakpoint.

Gnathostoma spinigerum in live Asian swamp eels (Monopterus spp.) from food markets and wild populations, United States.

PubMed

Cole, Rebecca A; Choudhury, Anindo; Nico, Leo G; Griffin, Kathryn M

2014-04-01

In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 wild-caught specimens. Nematodes were identified by morphologic features and ribosomal intergenic transcribed spacer-2 gene sequencing. Thirteen (27.7%) M. cuchia eels from markets were infected with 36 live G. spinigerum AL3: 21 (58.3%) in liver; 7 (19.4%) in muscle; 5 (13.8%) in gastrointestinal tract, and 3 (8.3%) in kidneys. Three (4.5%) wild-caught M. albus eels were infected with 5 G. turgidum AL3 in muscle, and 1 G. lamothei AL3 was found in a kidney (both North American spp.). Imported live eels are a potential source of human gnathostomiasis in the United States.

Performance evaluation of a second-generation elastic loop mobility system

NASA Technical Reports Server (NTRS)

Melzer, K. J.; Swanson, G. D.

1974-01-01

Tests were conducted to evaluate the mobility performance of a second-generation Elastic Loop Mobility System (ELMS II). Performance on level test lanes and slopes of lunar soil simulant (LSS) and obstacle-surmounting and crevasse-crossing capabilities were investigated. In addition, internal losses and contact pressure distributions were evaluated. To evaluate the soft-soil performance, two basic soil conditions were tested: loose (LSS1) and dense (LSS5). These conditions embrace the spectrum of soil strengths tested during recent studies for NASA related to the mobility performance of the LRV. Data indicated that for the tested range of the various performance parameters, performance was independent of unit load (contact pressure) and ELMS II drum angular velocity, but was influenced by soil strength and ELMS pitch mode. Power requirements were smaller at a given system output for dense soil than for loose soil. The total system output in terms of pull developed or slope-climbing capability was larger for the ELMS II operating in restrained-pitch mode than in free-pitch mode.

Repeated drought alters resistance of seed bank regeneration in baldcypress swamps of North America

USGS Publications Warehouse

Lei, Ting; Middleton, Beth A.

2018-01-01

Recurring drying and wetting events are likely to increase in frequency and intensity in predicted future droughts in the central USA and alter the regeneration potential of species. We explored the resistance of seed banks to successive droughts in 53 sites across the nine locations in baldcypress swamps in the southeastern USA. Along the Mississippi River Alluvial Valley and northern Gulf of Mexico, we investigated the capacity of seed banks to retain viable seeds after successive periods of drying and wetting in a greenhouse study. Mean differences in species richness and seed density were compared to examine the interactions of successive droughts, geographical location and water regime. The results showed that both species richness and total density of germinating seedlings decreased over repeated drought trials. These responses were more pronounced in geographical areas with higher annual mean temperature. In seed banks across the southeastern swamp region, most species were exhausted after Trial 2 or 3, except for semiaquatic species in Illinois and Tennessee, and aquatic species in Texas. Distinct geographical trends in seed bank resistance to drought demonstrate that climate-induced drying of baldcypress swamps could influence the regeneration of species differently across their ranges. Despite the health of adult individuals, lack of regeneration may push ecosystems into a relict status. Seed bank depletion by germination without replenishment may be a major conservation threat in a future with recurring droughts far less severe than megadrought. Nevertheless, the protection of moist refugia might aid conservation.

Ecological response of plant consumers to Middle-Upper Pennsylvanian extinctions in Illinois Basin coal swamps: Evidence from plant/arthropod interactions

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

Labandeira, C.; Phillips, T.

1992-01-01

Paleobotanical studies of coal-swamp vegetation during the Middle to Upper Pennsylvanian of North America indicate major changes from lycopsid dominated to tree-fern dominated coal-swamp forests as a result of extinction. This taxonomic shift from lycopsids to tree ferns should have implications on dependent feeding guilds, such as detritivores and herbivores. Comparative coal-ball evidence from the Springfield and Herrin Coals (Carbondale Fm.) and Calhoun Coal (Mattoon Fm.) is used to address this issue. The two major feeding guilds of Pennsylvanian coal-swamps were detritivores and herbivores. Detritivores were dominant throughout the interval. Evidence suggests an increasing presence of herbivores during the Desmoinesianmore » and especially during the Missourian. Based on identifications of tissue types found in coprolite types and plant tissue damage patterns, detritivores such as oribatid mites and an unknown stem-parenchyma consumer of Psaronius tree ferns occur before and after the extinction. Based on available evidence, detritivores apparently exhibited stability, particularly since the taxonomic affiliation of their food resource shifted considerably, thus indicating dietary specificities based instead on tissue type. There is evidence for herbivory by stem-miners on Missourian age tree-fern petioles; this distinctive behavior has not been reported for Desmoinesean or older deposits. The arthropod body-fossil record is consistent with this pattern: detritivore groups such as roaches survive the extinction largely intact, whereas other groups such as diverse protorthopterans,'' some of which were most likely herbivorous, experienced a significant extinction.« less

Quantifying climatic impacts on peatland in the Zoige basin, China

NASA Astrophysics Data System (ADS)

Gao, P.; Li, Z.; Hu, X.

2017-12-01

Actual evapotranspiration (ET) of the Zoige basin in the Yellow River source region of China is a critical parameter for understanding water balance of peatland in the Zoige basin and hence the cause of the changing land cover. Using daily meteorological data sets of Zoige, Hongyuan, and Maqu stations from 1967 to 2011, the well-known FAO56 Penman-Monteith (P-M) formula was selected to calculate the reference crop evapotranspiration (ET0) in combination with the crop coefficient method in which the crop coefficient Kc is modified in terms of local climatic conditions. By classifying land cover of the Zoige basin in to swamp, grassland, water surface, and desert, the actual ET cover time for each type was obtained. Since late 1990s, the ET0 increased along with the increased air temperature. Different from previous studies, the ET of the swamp was slightly lower than that of water surface, but was slightly larger than the difference between annual precipitation and runoff in the Zoige basin. The increase of ET in the past 45 years was small in comparison with the change of the annual precipitation. More specifically, the annual precipitation, which was about 560-860 mm, slightly decreased between 1967 and 1997, and increased 2.23% in the 1998-2011 period. These results allowed us to conclude that though the slightly increased ET might be a factor leading to the long-term swamp dewatering, it cannot be the primary cause of the degraded peatland swamp and grassland in the Zoige basin.

Ecology of tidal freshwater forests in coastal deltaic Louisiana and northeastern South Carolina: Chapter 9

USGS Publications Warehouse

Conner, William H.; Krauss, Ken W.; Doyle, Thomas W.

2007-01-01

Tidal freshwater swamps in the southeastern United States are subjected to tidal hydroperiods ranging in amplitude from microtidal (<0.1 m) to mesotidal (2-4 m), both having different susceptibilities to anthropogenic change. Small alterations in flood patterns, for example, can switch historically microtidal swamps to permanently flooded forests, scrub-shrub stands, marsh, or open water but are less likely to convert mesotidal swamps. Changes to hydrological patterns tend to be more noticeable in Louisiana than do those in South Carolina.The majority of Louisiana’s coastal wetland forests are found in the Mississippi River deltaic plain region. Coastal wetland forests in the deltaic plain have been shaped by the sediments, water, and energy of the Mississippi River and its major distributaries. Baldcypress (Taxodium distichum [L.] L.C. Rich.) and water tupelo (Nyssa aquatica L.) are the primary tree species in the coastal swamp forests of Louisiana. Sites where these species grow usually hold water for most of the year; however, some of the more seaward sites were historically microtidal, especially where baldcypress currently dominates. In many other locations, baldcypress and water tupelo typically grow in more or less pure stands or as mixtures of the two with common associates such as black willow (Salix nigra Marsh.), red maple (Acer rubrum L.), water locust (Gleditsia aquatic Marsh.), overcup oak (Quercus lyrata Walt.), water hickory (Carya aquatica [Michx. f.] Nutt.), green ash (Fraxinus pennsylvanica Marsh.), pumpkin ash (F. profunda Bush.), and redbay (Persea borbonia [L.] Sprengel) (Brown and Montz 1986).The South Carolina coastal plain occupies about two-thirds of the state and rises gently to 150 m from the Atlantic Ocean up to the Piedmont plateau. Many rivers can be found in the Coastal Plain with swamps near the coast that extend inland along the rivers. Strongly tidal freshwater forests occur along the lower reaches of redwater rivers (Santee, Great Pee Dee, and Savannah) that arise in the mountains and along the numerous blackwater rivers (Ashepoo, Combahee, Cooper, and Waccamaw) that arise in the coastal regions. Most of the tidal freshwater forests were converted to tidal rice fields in the 1700s (Porcher 1995). Canopy members of the present day forests include baldcypress, water tupelo, swamp tupelo (N. biflora Walt.), red maple, and Carolina ash (Fraxinus caroliniana Miller). Subcanopy and shrub species include Virginia sweetspire (Itea virginica L.), dwarf palmetto (Sabal minor (Jacquin) Pers.), coastal plain willow (Salix caroliniana Michx.), redbay, and water-elm (Planera aquatica Gmel.).

Imprecise (fuzzy) information in geostatistics

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

Bardossy, A.; Bogardi, I.; Kelly, W.E.

1988-05-01

A methodology based on fuzzy set theory for the utilization of imprecise data in geostatistics is presented. A common problem preventing a broader use of geostatistics has been the insufficient amount of accurate measurement data. In certain cases, additional but uncertain (soft) information is available and can be encoded as subjective probabilities, and then the soft kriging method can be applied (Journal, 1986). In other cases, a fuzzy encoding of soft information may be more realistic and simplify the numerical calculations. Imprecise (fuzzy) spatial information on the possible variogram is integrated into a single variogram which is used in amore » fuzzy kriging procedure. The overall uncertainty of prediction is represented by the estimation variance and the calculated membership function for each kriged point. The methodology is applied to the permeability prediction of a soil liner for hazardous waste containment. The available number of hard measurement data (20) was not enough for a classical geostatistical analysis. An additional 20 soft data made it possible to prepare kriged contour maps using the fuzzy geostatistical procedure.« less

Field verification of undercut criteria and alternatives for subgrade stabilization in the Piedmont area.

DOT National Transportation Integrated Search

2016-02-15

Work performed in this research project was in support of the effort by the North Carolina Department of Transportation to develop criteria to discern the need for undercutting soft soils and the adequacy of the subgrade after stabilization measures ...

Evaluation of bearing capacity of piles from cone penetration test data : technical summary.

DOT National Transportation Integrated Search

1999-11-01

Among the different in situ tests, cone penetration test (CPT) is considered the most frequently used method for characterization of geomedia. Due to the soft nature of soil deposits in Louisiana, the CPT is considered a perfect tool for characteriza...

Design and Test of an Improved Crashworthiness Small Composite Airframe

NASA Technical Reports Server (NTRS)

Terry, James E.; Hooper, Steven J.; Nicholson, Mark

2002-01-01

The purpose of this small business innovative research (SBIR) program was to evaluate the feasibility of developing small composite airplanes with improved crashworthiness. A combination of analysis and half scale component tests were used to develop an energy absorbing airframe. Four full scale crash tests were conducted at the NASA Impact Dynamics Research Facility, two on a hard surface and two onto soft soil, replicating earlier NASA tests of production general aviation airplanes. Several seat designs and restraint systems including both an air bag and load limiting shoulder harnesses were tested. Tests showed that occupant loads were within survivable limits with the improved structural design and the proper combination of seats and restraint systems. There was no loss of cabin volume during the events. The analysis method developed provided design guidance but time did not allow extending the analysis to soft soil impact. This project demonstrated that survivability improvements are possible with modest weight penalties. The design methods can be readily applied by airplane designers using the examples in this report.

Sulfur-Rich Rocks and Dirt (False Color)

NASA Technical Reports Server (NTRS)

2005-01-01

NASA's Mars Rover Spirit has been analyzing sulfur-rich rocks and surface materials in the 'Columbia Hills' in Gusev Crater on Mars. This image of a very soft, nodular, layered rock nicknamed 'Peace' in honor of Martin Luther King Jr. shows a 4.5-centimeter-wide (1.8-inch-wide) hole Spirit ground into the surface with the rover's rock abrasion tool. The high sulfur content of the rock measured by Spirit's alpha particle X-ray spectrometer and its softness measured by the abrasion tool are probably evidence of past alteration by water. Spirit's panoramic camera took this false-color image on martian day, or sol, 381 (Jan. 27, 2005), using Pancam filters at wavelengths of 750, 530, and 430 nanometers. Darker red hues in the image correspond to greater concentrations of oxidized soil and dust. Bluer hues correspond to sulfur-rich rock excavated or exposed by the abrasion tool and not as heavily coated with soils or not as highly oxidized.

Prefabricated Vertical Drain (PVD) and Deep Cement Mixing (DCM)/Stiffened DCM (SDCM) techniques for soft ground improvement

NASA Astrophysics Data System (ADS)

Bergado, D. T.; Long, P. V.; Chaiyaput, S.; Balasubramaniam, A. S.

2018-04-01

Soft ground improvement techniques have become most practical and popular methods to increase soil strength, soil stiffness and reduce soil compressibility including the soft Bangkok clay. This paper focuses on comparative performances of prefabricated vertical drain (PVD) using surcharge, vacuum and heat preloading as well as the cement-admixed clay of Deep Cement Mixing (DCM) and Stiffened DCM (SDCM) methods. The Vacuum-PVD can increase the horizontal coefficient of consolidation, Ch, resulting in faster rate of settlement at the same magnitudes of settlement compared to Conventional PVD. Several field methods of applying vacuum preloading are also compared. Moreover, the Thermal PVD and Thermal Vacuum PVD can increase further the coefficient of horizontal consolidation, Ch, with the associated reduction of kh/ks values by reducing the drainage retardation effects in the smear zone around the PVD which resulted in faster rates of consolidation and higher magnitudes of settlements. Furthermore, the equivalent smear effect due to non-uniform consolidation is also discussed in addition to the smear due to the mechanical installation of PVDs. In addition, a new kind of reinforced deep mixing method, namely Stiffened Deep Cement Mixing (SDCM) pile is introduced to improve the flexural resistance, improve the field quality control, and prevent unexpected failures of the Deep Cement Mixing (DCM) pile. The SDCM pile consists of DCM pile reinforced with the insertion of precast reinforced concrete (RC) core. The full scale test embankment on soft clay improved by SDCM and DCM piles was also analysed. Numerical simulations using the 3D PLAXIS Foundation finite element software have been done to understand the behavior of SDCM and DCM piles. The simulation results indicated that the surface settlements decreased with increasing lengths of the RC cores, and, at lesser extent, increasing sectional areas of the RC cores in the SDCM piles. In addition, the lateral movements decreased by increasing the lengths (longer than 4 m) and, the sectional areas of the RC cores in the SDCM piles. The results of the numerical simulations closely agreed with the observed data and successfully verified the parameters affecting the performances and behavior of both SDCM and DCM piles.