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Ecosystem disturbances that remove vegetation and disturb surface soils are major causes of excessive soil erosion and can result in accelerated transport of soils contaminated with hazardous materials. Accelerated wind erosion in disturbed lands that are contaminated is of particular concern because of potential increased inhalation exposure, yet measurements regarding these relationships are lacking. The importance of this was highlighted when, in May of 2000, the Cerro Grande fire burned over roughly 30% of Los Alamos National Laboratory (LANL), mostly in ponderosa pine (Pinus ponderosa) forest, and through areas with soils containing contaminants, particularly excess depleted and natural uranium. Additionally,...
Deposition of suspended dust near eroding source fields can have detrimental effects on vegetation, as well as on soil and water quality. This study was undertaken to quantify dust deposition within 200 m of a source field during wind erosion events. Erosion was measured with BSNE samplers on a small field of Amarillo fine sandy loam at field at Big Spring, TX. Suspension-sized dust discharge averaged 33 � 5 per cent of the total sediment discharge and ranged from 18�0 to 147�4 kg m?1 during eight selected storm events. Within 200 m of the source field boundary, dust collected in deposition samplers placed above a vegetated surface averaged 34 per cent of initial dust discharge. Predicted deposition, according to...
The recent upsurge in research attention to aeolian dust has shown that dust transport systems operate on very large spatial and temporal scales, and involve much larger quantities of sediment than was previously realized. An inevitable consequence of this is that researchers from a range of neighbouring disciplines, including ecology, are beginning to realize that this new knowledge has important implications for their study areas. In the present paper, we examine the ecological implications (real and potential) of this expanding knowledge of dust transport systems, with a particular emphasis upon the Australian dust transport system. We track these ecological effects from source to sink. At source, wind erosion–soil–vegetation...
The aeolian accumulation of natural atmospheric dust in a desert environment was investigated during a 24-month experiment. Accumulation was measured with marble collectors every month. At the same time, wind speed, dust concentration, dew formation and rainfall were recorded. Atmospheric stability was measured from a 90 m tower several km from the test site. Dust accumulation by day was systematically higher than dust accumulation at night. Also, dust concentration was higher, but the higher concentrations cannot completely explain die higher accumulation values. Both average monthly concentration and accumulation are considerably influenced by the occurrence of high-magnitude dust events, either dust storms or...
This study evaluates biomarkers of mercury exposure among residents of Horlivka, a city in eastern Ukraine located in an area with geologic and industrial sources of environmental mercury, and residents of Artemivsk, a nearby comparison city outside the mercury-enriched area. Samples of urine, blood, hair, and nails were collected from study participants, and a questionnaire was administered to obtain data on age, gender, occupational history, smoking, alcohol consumption, fish consumption, tattoos, dental amalgams, home heating system, education, source of drinking water, and family employment in mines. Median biomarker mercury concentrations in Artemivsk were 0.26 μg/g-Cr (urine), 0.92 μg/L (blood), 0.42 μg/g...
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The focus of the study, associated with these data, is a 540-km2 area at the low-elevation northern end of the 1460-km2 Milford Flat Fire in west-central Utah, and includes burned and adjacent unburned areas. Uncontrolled wildfire in arid and semiarid ecosystems has become an increasing concern in recent decades. Active rehabilitation of fire-affected areas is often quickly initiated to minimize long-term ecosystem damage. However, the complex soil-geomorphic-vegetation patterns and low and variable moisture conditions in these regions makes restoration challenging. To further inform these post-fire management decisions, we present results from 5-years of vegetation and sediment flux monitoring following the Milford...
Aeolian processes are of particular importance in dryland ecosystems where ground cover is inherently sparse because of limited precipitation. Dryland ecosystems include grassland, shrubland, savanna, woodland, and forest, and can be viewed collectively as a continuum of woody plant cover spanning from grasslands with no woody plant cover up to forests with nearly complete woody plant cover. Along this continuum, the spacing and shape of woody plants determine the spatial density of roughness elements, which directly affects aeolian sediment transport. Despite the extensiveness of dryland ecosystems, studies of aeolian sediment transport have generally focused on agricultural fields, deserts, or highly disturbed...
This study utilized spaceborne multispectral thermal infrared (TIR) data to document spatial relationships of surface sediments over time in a modern depositional environment associated with dust emissions, Soda Lake playa, Mojave Desert, United States. The approach employed here involved time-series TIR data acquired from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and a linear spectral mixture analysis. An automated algorithm was applied to derive emissivity image endmembers. Evaluation of the chosen endmembers revealed that they can be categorized into five major spectra classes based on diagnostic absorption features. Each spectrum has been identified in relation to mineral abundance...
The interactions between playa hydrology and playa-surface sediments are important factors that control the type and amount of dust emitted from playas as a result of wind erosion. The production of evaporite minerals during evaporative loss of near-surface ground water results in both the creation and maintenance of several centimeters or more of loose sediment on and near the surfaces of wet playas. Observations that characterize the texture, mineralogic composition and hardness of playa – surfaces at Franklin Lake, Soda Lake and West Cronese Lake playas in the Mojave Desert (California), along with imaging of dust emission using automated digital photography, indicate that these kinds of surface sediment are...
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Snow cover duration in a seasonally snow covered mountain range (San Juan Mountains, USA) was found to be shortened by 18 to 35 days during ablation through surface shortwave radiative forcing by deposition of disturbed desert dust. Frequency of dust deposition and radiative forcing doubled when the Colorado Plateau, the dust source region, experienced intense drought (8 events and 39?59 Watts per square meter in 2006) versus a year with near normal precipitation (4 events and 17?34 Watts per square meter in 2005). It is likely that the current duration of snow cover and surface radiation budget represent a dramatic change from those before the widespread soil disturbance of the western US in the late 1800s that...
Wind erosion and aeolian transport processes are under studied compared to rainfall-induced erosion and sediment transport on burned landscapes. Post-fire wind erosion studies have predominantly focused on near-surface sediment transport and associated impacts such as on-site soil loss and site fertility. Downwind impacts, including air quality degradation and deposition of dust or contaminants, are also likely post-fire effects; however, quantitative field measurements of post-fire dust emissions are needed for assessment of these downwind risks. A wind erosion monitoring system was installed immediately following a desert sagebrush and grass wildfire in southeastern Idaho, USA to measure wind erosion from the burned...
Trends in snow acidity reflect the balance between strong acid inputs and reactions with neutralizing materials. Carbonate dust can be an important contributor of buffering capacity to snow; however, its concentration in snow is difficult to quantify because it dissolves rapidly in snowmelt. In snow with neutral or acidic pH, most calcite would dissolve during sample melting if snow samples were processed using standard techniques. Here a method is described for separating particulate carbonate matter from snow. Snow samples were melted in solutions close to saturation with calcite, decreasing the dissolution rate by a factor of 100?200 compared with natural melting of snow. Particulate matter larger than 0.45 ?m...
Diatom assemblages in sediments from two subalpine lakes in the Uinta Mountains, Utah, show asynchronous changes that are related to both anthropogenic and natural inputs of dust. These lakes are downwind of sources of atmospheric inputs originating from mining, industrial, urban, agricultural and natural sources that are distributed within tens to hundreds of kilometers west and south of the Uinta Mountains. Sediment cores were retrieved from Marshall and Hidden lakes to determine the impacts of atmospheric pollution, especially metals. Paleolimnological techniques, including elemental analyses and 210Pb and 239+240Pu dating, indicate that both lakes began receiving eolian inputs from anthropogenic sources in the...
A number of studies have shown that dust delivers essential nutrients that sustain terrestrial productivity over millennia. Dust, however, contains a range of elements ranging from base cations, N and P, to heavy metals. Some of these elements will stimulate primary productivity over the time scale of soil development while others, such as metals, could inhibit biological activity. As dust accumulates, it also influences water flux and availability by altering soil texture. We are examining the ecological impacts of dust accumulation in Canyonlands National Park in Utah. Using magnetic susceptibility as a proxy for far-traveled dust, we have established transects in sandy surficial deposits (50-90% sand) in which...
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Rock-derived nutrients in soils originate from both local bedrock and atmospheric dust, including dust from far-distant sources. Distinction between fine particles derived from local bedrock and from dust provides better understanding of the landscape-scale distribution and abundance of soil nutrients. Sandy surficial deposits over dominantly sandstone substrates, covering vast upland areas of the central Colorado Plateau, typically contain 5–40% silt plus clay, depending on geomorphic setting and slope (excluding drainages and depressions). Aeolian dust in these deposits is indicated by the presence of titanium-bearing magnetite grains that are absent in the sedimentary rocks of the region. Thus, contents of...
An ongoing project monitors modern dust accumulation in the arid southwestern United States to (1) determine the rate and composition of dust inputs to soils and (2) relate dust accumulation to weather patterns to help predict the effects of climate change on dust production and accumulation. The 16-year records of 35 dust-trap sites in the eastern Mojave Desert and southern Great Basin reveal how generation and accumulation of dust, including the silt-clay, carbonate, and soluble-salt fractions, is affected by the amount and seasonal distribution of rainfall and the behavior of different source types (alluvium, dry playas, and wet playas). Accumulation rates (fluxes) of the silt-clay fraction of dust, including...
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Dust deposition in the Rocky Mountains may be an important biogeochemical flux from upwind ecosystems. Seasonal (winter/spring) dust mass fluxes to the San Juan Mountains during the period from 2004 to 2008 ranged from 5 to 10 g m?2, with individual deposition events reaching as high as 2 g m?2. Dust deposited in the San Juan Mountains was primarily composed of silt- and clay-sized particles, indicating a regional source area. The concentrations of most major and minor elements in this dust were similar to or less than average upper continental crustal concentrations, whereas trace element concentrations were often enriched. In particular, dust collected from the San Juan Mountain snowpack was characterized by enrichments...
Dust deposition to mountain snow cover, which has increased since the late 19(th) century, accelerates the rate of snowmelt by increasing the solar radiation absorbed by the snowpack. Snowmelt occurs earlier, but is decoupled from seasonal warming. Climate warming advances the timing of snowmelt and early season phenological events (e.g., the onset of greening and flowering); however, earlier snowmelt without warmer temperatures may have a different effect on phenology. Here, we report the results of a set of snowmelt manipulations in which radiation-absorbing fabric and the addition and removal of dust from the surface of the snowpack advanced or delayed snowmelt in the alpine tundra. These changes in the timing...
Soil analyses and measurements with the Portable In Situ Wind Erosion Laboratory (PI-SWERL) were conducted on 16 soil types in an area heavily affected by off-road vehicle (ORV) driving. Measurements were performed in ORV trails as well as on undisturbed terrain to investigate how ORV driving affects the vulnerability of a soil to emit PM10 (particles<10microm), during the driving as well as during episodes of wind erosion. Particular attention is paid to how the creation of a new trail affects those properties of the topsoil that determine its capability to emit PM10. Also, recommendations are given for adequate management of ORV-designed areas. The type of surface (sand, silt, gravel, drainage) is a key factor...
Soil erosion is driven by not only aeolian but also fluvial transport processes, yet these two types of processes are usually studied independently, thereby precluding effective assessment of overall erosion, potential interactions between the two drivers, and their relative sensitivities to projected changes in climate and land use. Here we provide a perspective that aeolian and fluvial transport processes need to be considered in concert relative to total erosion and to potential interactions, that relative dominance and sensitivity to disturbance vary with mean annual precipitation, and that there are important scale-dependencies associated with aeolian–fluvial interactions. We build on previous literature...
map background search result map search result map Impact of disturbed desert soils on duration of mountain snow cover Contemporary geochemical composition and flux of aeolian dust to the San Juan Mountains, Colorado, United States Atmospheric dust in modern soil on aeolian sandstone, Colorado Plateau (USA): Variation with landscape position and contribution to potential plant nutrients Milford Flat Fire—Data Milford Flat Fire—Data Impact of disturbed desert soils on duration of mountain snow cover Contemporary geochemical composition and flux of aeolian dust to the San Juan Mountains, Colorado, United States Atmospheric dust in modern soil on aeolian sandstone, Colorado Plateau (USA): Variation with landscape position and contribution to potential plant nutrients