Sites In Missouri Research Articles

Selective remediation of contaminated sites using a two-level multiphase strategy and geostatistics.

Selective soil remediation aims to reduce costs by cleaning only the fraction of an exposure unit (EU) necessary to lower the average concentration below the regulatory threshold. This approach requires a prior stratification of each EU into smaller remediation units (RU) which are then selected according to various criteria. This paper presents a geostatistical framework to account for uncertainties attached to both RU and EU average concentrations in selective remediation. The selection of RUs is based on their impact on the postremediation probability for the EU average concentration to exceed the regulatory threshold, which is assessed using geostatistical stochastic simulation. Application of the technique to a set of 600 dioxin concentrations collected at Piazza Road EPA Superfund site in Missouri shows a substantial decrease in the number of RU remediated compared with single phase remediation. The lower remediation costs achieved by the new strategy are obtained to the detriment of a higher risk of false negatives, yet for this data set this risk remains below the 5% rate set by EPA region 7.

Mississippian Connections with Mill Creek and Cambria

This paper reviews the evidence for Mill Creek-Cambria interaction in the western Prairie Peninsula with various regional Mississippian polities. Limited evidence in the form of Cambria trade pottery has been reported from at least five Mill Creek sites. Of interest is the extensive presence of Mississippian-inspired pottery and decorative styles at both the Cambria site and many Mill Creek, Initial variant Middle Missouri sites, which suggests that all are examples of regional Stirling horizon activity. Models for Mill Creek-Mississippian contact during the Stirling horizon are reviewed with emphasis on possible roles of Cambria and Mill Creek with regard to Upper Mississippi Valley Mississippian sites. The conclusion reached is that some Initial Middle Missouri tradition-Mississippian contacts such as Mill Creek were substantial and directed by Cahokia elite, while others were developed regionally with specific Mississippian centers, such as Cambria with the Red Wing locality.

INTERRELATIONSHIPS AMONG LANDSCAPES, NDVI, AND STREAM WATER QUALITY IN THE U.S. CENTRAL PLAINS

During late spring through summer of 1994 and 1995, 290 randomly selected stream sites in Nebraska, Kansas, and Missouri were sampled once for several parameters including conductivity, turbidity, total phosphorus, nitrate-nitrite nitrogen, the index of biotic integrity, and a habitat index. Based on landscape data from watersheds that were delineated for each sampling location, interrelationships were examined between these water quality parameters and land use/land cover, the normalized difference vegetation index (NDVI), and vegetation phenological metrics derived from the NDVI. Statistically signif- icant relationships were found between NDVI values and the derived metrics with the stream condition parameters ( r values to 0.8, a5 0.05). The NDVI or vegetation pheno- logical metrics (VPMs) were more highly correlated to the selected stream condition pa- rameters than were the land use/land cover proportions. Knowledge of the general land use/land cover setting within the watersheds, however, was important for interpreting these relationships. The most common variables associated with the stream data were early spring NDVI values or VPMs associated with the date of onset of greenness. These results dem- onstrate the utility of NDVI and VPMs as broad-scale environmental indicators of watershed conditions.

Lack of Predictable Race Shift in Heterodera glycines-Infested Field Plots.

Soybean cultivars with different sources of resistance to Heterodera glycines were grown at three locations initially infested with races 2, 3, and 6 in order to investigate H. glycines race shift in field populations. Each spring and fall, soil samples were taken from each plot and race tests were conducted to evaluate effects of cultivar and time of sampling. Field experiments were paired field plots rotated annually with corn since 1991. Cultivars included at the northern and central Missouri sites were Williams 82 (susceptible to H. glycines), Linford (PI 88788 source of resistance), MFA 9043 (Peking) replaced by Morsoy 9345 (Peking and PI 88788) from 1995 to 1997, and Jackson II (Peking + PI 88788) replaced by Asgrow 3431 (Peking and PI 88788) in 1996-97. Cultivars at the southern Missouri site were Essex or Hutcheson (susceptible to H. glycines), Forrest (Peking), Hartwig (PI 437654), and Rhodes (PI 88788 + Peking). In 1995, race tests were performed at four temperature regimes to determine temperature effects on race designations. Race shifts were not predictable based on the source of resistance of the soybean cultivar planted. Variability in female numbers on Lee 74 among tests caused changes in female indices (FI). Furthermore, race designations were influenced by the time of sampling and temperature at which the race tests were conducted. The variability of H. glycines populations in both field and greenhouse situations diminishes the value of race test results when making cultivar recommendations.

COUPLING SOYBEAN CYST NEMATODE DAMAGE TO CROPGRO–SOYBEAN

The soybean cyst nematode (SCN) Heterodera glycines Ichinohe is responsible for substantial economic losses in soybean (Glycine max L. Merr.) production throughout the U.S. Results from past efforts to quantify the severity of crop damage resulting from SCN are often subject to variable experimental conditions resulting from differences in weather, soil type, and cultivar. Because of the difficulty in accounting for these variables, a process–oriented crop growth simulation model was chosen as a platform for studying the dynamics of SCN damage and for transferring knowledge between crop production scenarios. The objective of this study was to develop and evaluate hypotheses for coupling SCN damage to the process–oriented crop growth model CROPGRO–Soybean. A monomolecular function was used to relate daily SCN damage to initial population density of SCN eggs. The equation was incorporated into the crop model in order to test two hypotheses of how SCN damage occurs. The first hypothesis was that SCN reduce daily photosynthesis (Pg), while the second hypothesis was that SCN reduce daily potential root water uptake (RWU). Canopy biomass data collected in 1997 and 1998 from a site in Iowa were used to estimate damage function parameters for two distinct coupling points, one applied to reduce daily photosynthesis (Pg) and the other applied to reduce daily potential root water uptake (RWU). Function parameters were estimated by minimizing the log transformation of root mean square error (RMSE) between predicted and measured canopy biomass collected every 2 weeks during the season in Iowa. Biomass data collected in 1997 and 1998 from an independent site in Missouri were used to validate the SCN damage models. The minimum root mean squared errors (RMSE) of canopy and grain biomass were 0.245 and 0.198 log10(kg ha –1 ), respectively, for the RWU coupling point, and 0.238 and 0.193 log10(kg ha –1 ), respectively, for the Pg coupling point at the independent site in Missouri. The damage functions transferred very well to the independent site. Validation showed that the Pg coupling point represented the variability of both canopy and final yield data slightly better than the RWU coupling point.

Design and Installation of Horizontal Wick Drains for Landslide Stabilization

One of the most effective options to stabilize landslides is to reduce the amount of water they contain by installing horizontal drains. A new type of horizontal drain material, geosynthetic wick drains, and a new installation method, driving drains rather than drilling them, were evaluated. Horizontal wick drains offer several advantages over conventional horizontal drains: They resist clogging, are inexpensive, may be deformed without rupture, and may be installed by unskilled laborers with a minimal investment in equipment. More than 100 drains were installed at eight sites in Missouri, Colorado, and Indiana using bulldozers, backhoes, and standard wick drain-driving cranes. Drains have been driven 30 m through materials with standard penetration test values as high as 28. Both experience and research indicate that drains should be installed in clusters that fan outward, aiming for average spacing of 8 m for typical clayey soils. As with drilled drains, initially some drains are expected to be dry, although these drains often become active during wet periods and serve as an important part of the overall slope stabilization scheme. Drain effectiveness is expected to build over the first few years as the effects of soil smear during drain installation are removed, peaking at 3 to 6 years after installation. The effectiveness is then expected to decrease as fine particles slowly clog the drain pores. From published tests, clogging appears to occur slowly enough in typical clay soils that the drain life is comparable with the project life.

ALS-resistantHelianthus annuusinterference inGlycine max

Field studies were conducted to determine the effect of early-season and early- plus late-season acetolactate synthase–resistant Helianthus annuus interference on Glycine max and H. annuus growth and yield at two sites in Missouri. Helianthus annuus densities of 3 plants m−2 were established shortly after G. max emergence in all plots except the weed-free check. To study early-season interference, H. annuus were removed with postemergence glyphosate (0.84 kg ae ha−1) 2, 4, 6, and 8 wk after planting (WAP) and kept weed-free for the rest of the growing season. Glycine max yields were not different with 2, 4, 6, or 8 wk of early-season interference at either location. To study early- plus late-season interference, H. annuus densities were established at 3 plants m−2. They were then removed 2, 4, 6, or 8 WAP with glyphosate and subsequently reestablished at the same density within 2 wk after removal by newly emerging and transplanted H. annuus. These H. annuus were allowed to remain in the field for the remainder of the growing season. This provided a weed-free period of approximately 2 wk during the growing season beginning 2, 4, 6, or 8 WAP. Season-long interference and no-interference treatments were also included. Glycine max yields were reduced 47 to 72% with season-long interference. Helianthus annuus vegetative dry matter was approximately 56% lower at Columbia than at Miami. Glycine max yields tended to increase as the weed-free period was delayed into the growing season. Early-season weed-free periods (2 to 4 and 4 to 6 WAP) allowed H. annuus to become re-established before G. max formed a canopy and resulted in larger amounts of H. annuus biomass and seed production as well as G. max yield losses of 15 to 80%. Re-establishment of H. annuus in 6 to 8 WAP and 8 to 10 WAP weed-free treatments generally resulted in the plants surviving for only a few weeks after establishment and not producing seed or reducing G. max yield.

MODELS AND REALITY: TIME–ENERGY TRADE-OFFS IN PECTORAL SANDPIPER (CALIDRIS MELANOTOS) MIGRATION

We used a combination of modeling and field studies to determine the spring migration strategy of Pectoral Sandpipers (Calidris melanotos). We developed a dynamic programming model to predict patterns that should be detected along the migratory route if Pectoral Sandpipers use a strategy of early arrival at the breeding grounds (time minimization) or arrival at the breeding grounds with excess energy reserves (energy maximization). The predictions were then compared to data collected at stopover sites in the mid-continent of North America and at the breeding grounds in Alaska over a 5-yr period (1992–1996). During spring migration to their Arctic breeding grounds, Pectoral Sandpipers stop periodically to feed. The length-of-stay at such stopovers, for both time minimizers and energy maximizers, was predicted to vary inversely with date and body fat, and to vary directly with invertebrate abundance. We observed that: (1) length-of-stay was negatively correlated with capture date in Missouri and Nebraska, but not in Texas; (2) length-of-stay was not correlated with body fat at any site; and (3) length-of-stay was positively related to invertebrate abundance at the Nebraska and Missouri sites. As the population moves northward in the spring, three regional patterns are diagnostic of migration strategy. Length-of-stay was predicted to be bimodal (energy maximizer) or constant (time minimizer) with respect to latitude, but neither pattern was observed. The migration window, or period of time during which spring migrants occur, was predicted to decrease with increasing latitude for time minimizers, a pattern that was seen for both males and females. Body fat was predicted to increase with latitude for energy maximizers, a pattern that was seen for females but not males. The evidence suggests that males and females differ in their spring migration strategies. Both sexes attempt to arrive in the Arctic as early as possible after ice breakup in the spring. Additionally, females gain significantly higher fat loads than males (up to 60% body fat for females) during migration, and these energy reserves may later enhance female reproductive success. However, females gained large fat loads only during 1993 and 1995, which had above normal spring precipitation along the migration route. We believe that the correlation between female body fat and precipitation reflects an abundance of high-quality stopover habitat during wet springs. This view is supported by model sensitivity analyses showing that the spacing and quality of stopover habitat can strongly influence observed migration patterns. Our results suggest the need to focus additional research on the landscape-level features of the flyway through which shorebirds migrate.

Modeling Hydrologic and Water Quality Responses to Grass Waterways

The impact of vegetation filter strips on runoff, sediment yield, and atrazine loss from a cultivated field was investigated using a physically based, distributed watershed model. The field to which the model is applied has a gentle to flat sloping surface covered by a thin topsoil layer underlain by a claypan and is located in the Goodwater Creek watershed, a USDA research site in central Missouri. The model, which works on a cell basis, was developed to route runoff, sediment, and soluble chemical downslope from one cell to the next. The spatial variability of soil, depth of the topsoil, and vegetation are allowed among cells; each cell, however, is represented as a homogeneous unit. Our investigation indicates that changing waterway cover from natural sparse vegetation to dense grass has great potential for retarding runoff and reducing sediment loss, but it is not effective for controlling atrazine loss on claypan soils.

Calibrating the Root Zone Water Quality Model

AbstractTechniques to reliably calibrate computer models are needed before the models can be applied to help solve natural resource problems. The USDA‐ARS Root Zone Water Quality Model (RZWQM) is a comprehensive simulation model designed to predict hydrologic and chemical response, including potential for ground‐water contamination, of agricultural management systems. RZWQM Version 3.2 was calibrated and evaluated at sites in Iowa, Minnesota, Missouri, Nebraska, and Ohio as part of the Management Systems Evaluation Areas (MSEA) project and at a site near Sterling in northeastern Colorado. Soil horizon description and a description of the physical and hydraulic properties of the soil were required to initialize the model. Calibration for nutrient cycling involved adjusting the model coefficients for mineralization, infiltration, and denitrification. Initial N pool sizes were estimated using medium to long‐term computer simulations. Maximum N uptake rate, plant respiration, specific leaf area, and the effect of age at the time of propagule development and senescence were used to calibrate the plant production and yield component. To match the observed results for soil water, N, and plant growth, an iterative approach for calibrating the model was followed. When done methodically, total biomass estimates were within 5%, yield estimates were within l0%, and N uptake was within 20% of field measurements. Calibration of the C and N dynamics module produced results that were generally within 20 to 50 kg ha−1 of measured values for soil profile NO−3‐N. Independent evaluations of the calibrated model focused on four indicator output variables related to plant growth—total biomass, yield, N uptake, and N in the soil profile. Predictions matched the observed data in most cases. The crop model is very sensitive to plant N content. Even small errors in simulating N uptake levels can result in substantial errors in estimates of yield and total aboveground biomass. The model predicted biomass and yield well on irrigated and most dryland management systems and adequately simulated crop variables at various positions along the landscape.

The Big Eddy Site: A Multicomponent Paleoindian Site on the Ozark Border, Southwest Missouri

Relatively few deep, stratified, multi component Paleo indian sites have been found in alluvial contexts in North America. Recent excavations at the Big Eddy site in southwest Missouri, however, reveal the presence of unique, stratified Paleoindian horizons containing Clovis, Dalton, and San Patrice components. Limited excavations below the Clovis stratum also provide strong evidence for the presence of one or more pre-Clovis horizons. Results of the work at Big Eddy, including discussions of geomorphic contexts, prehistoric components, foatures, artifacts, and radiocarbon assays, are provided

Eastern gamagrass (Tripsacum dactyloides) root penetration into and chemical properties of claypan soils

Claypans restrict rooting depth and availability of moisture and nutrients to plants during periods of drought. Eastern gamagrass [Tripsacum dactyloides var. dactyloides (L.) L] often remains green during summer droughts, while other plants turn brown. Questions arose whether eastern gamagrass roots could penetrate claypans to obtain needed moisture. Pits were dug (2m deep) under eastern gamagrass plants that had been growing 50+ and 5+ years at two sites in Missouri. Clay contents were 30 to 50% in soil layers below 30 cm, and moisture was not limiting in these deep soil layers. Soil pHCa, in the lower soil layers, except at 180 cm, was below 5.0, and in some cases near 4.0. Extractable Al was especially high in the 90 and 120 cm deep soil layers where pH was low. Extractable Ca, Mg, and K increased with soil depth. The eastern gamagrass roots effectively penetrated claypan soils. Root lengths and root weights were extensive to 180 cm depth, and decreased from the surface with soil depth. Roots of eastern gamagrass were aerenchymous (having cellular compartments which allow air movement) at all depths, were mycorrhizal to at least 150 cm depth, and had relatively high tolerance to acidic Al toxic Tatum subsoil (Typic Hapludult) and toxic levels of Al in nutrient solution. The eastern gamagrass roots also provided root channels through claypans, which could enable new eastern gamagrass or other plant roots to grow into deeper soil layers.

MODELS OF GERIATRICS PRACTICE*: A Model for Nurse Case‐Managed Home Care Using Televideo

OBJECTIVE: To determine the feasibility of implementing a home care program, utilizing two‐way interactive televideo, as a lower cost alternative to traditional in‐home care.SETTING: Registered nurses used a proprietary telehome care system to provide home care services to patients in congregate senior apartments and individual patient homes during 1996.PARTICIPANTS: A total of 46 patients from five sites in Kansas and Missouri, with multiple medical problems, who were living at home, were enrolled in the program.INTERVENTION: All enrolled patients received an individualized, computer integrated, nursing care plan that utilized outcome‐based clinical pathways and scheduled televideo nursing interventions. All enrolled patients received a comprehensive initial in‐home assessment as well as comprehensive follow‐up in‐home assessments every 60 days. Patients received an average of four telehome care visits per week for an average of 12.25 minutes per visit. Nurses were estimated to be able to perform approximately 24 telehome care visits per day using the system.CONCLUSIONS: A comprehensive home care program that combines two‐way interactive televideo with standardized, computerized patient assessments and care planning can provide nursing services in the home effectively. Telehome care may be a cost‐effective complement to traditional, in‐home care. J Am Geriatr Soc 45: 1523–1528, 1997.

Local citizens' group taking heat from EPA

Following the discovery of yet another dioxins-contaminated site in eastern Missouri, the Environmental Protection Agency Region VII sent a letter to a local citizens' group demanding, within five ...

Tornado damage and initial recovery in three adjacent, lowland temperate forests in Missouri

Abstract. We surveyed tornado damage 14 months after disturbance in three adjacent forest sites in southeastern Missouri, USA: upland, an occasionally‐flooded lowland and a frequently flooded swamp. We analysed three 0.09‐ha plots in the swamp, and three 0.04‐ha plots in the other sites and recorded the herbaceous‐layer in five 1‐m2 quadrats per plot.Overall, 30 % of the individuals and 64 % of the basal area of these sites was blown down. However, mortality was less than structural damage: 20 % of the trees were dead 14 months post‐disturbance, an intermediate level of mortality relative to other wind disturbances. Damage varied widely among species, sites and tree sizes, but large trees of all species were most likely to be damaged and least likely to resprout.While damage was greatest in the wettest site, we attribute the increase to larger tree sizes and lower density there, rather than to inherent rooting instability. This study suggests that different forest composition and structure may be sufficient to cause differential damage, without topographic effects. Herbaceous‐layer response was more rapid than in a previously reported tornado windthrow in Pennsylvania, and was dominated by fast‐growing, shade‐intolerant forbs.

Effects of temperature and photoperiod on tropical soda apple (Solanum viarumDunal) and its potential range in the U.S.

Tropical soda apple is an exotic perennial pasture weed currently reported in the U.S. only from Florida, Georgia, Alabama, Mississippi, and South Carolina. In experiments to determine its environmental requirements and potential range, tropical soda apple was grown in growth chambers in 16 day/night temperature regimes ranging from 18/8 to 36/26 C. After 100 d of growth, maximum height, leaf area, and shoot biomass occurred at day/night temperatures ranging from 24/26 to 36/26 C. The plants achieved 50% or more of maximum leaf area, biomass, and height at 18/26, 24/20, 24/26, 30/26, and 36/26 C. Plants survived in 8 C nights with day temperatures of 18 to 36 C, but biomass and leaf area were only 3 to 10% of maximum. Leaf appearance rate was linearly related to mean temperature over the range of 11.3 to 29.3 C, with a slope coefficient of 0.018 leaves/day/degree C. Flowering was delayed by photoperiods shorter than 10 h or temperatures lower than 24/20 C. In favorable temperatures, plants flowered within 60 d after emergence in photoperiods ranging from 8 to 16 h. Artificially pollinated flowers produced fruit with germinable seeds within 6 to 7 wk, at temperatures ranging from 23/17 to 32/26 C. A regression equation relating vegetative growth to day and night temperatures indicated that tropical soda apple could achieve 30% or more of its maximum growth rate during 7 mo of the year in southern Alabama, Louisiana, and Texas and during 4 to 5 mo of the year at sites in Georgia, South Carolina, North Carolina, Virginia, Tennessee, Kentucky, Illinois, Arkansas, Missouri, Kansas, and Oklahoma. Neither temperature nor photoperiod will limit its further spread in the southern U.S. and adjacent regions.

Comorbidity of anxiety disorders in a multicenter anxiety study

From 11 sites in New England and Missouri, 711 patients with ≥ one of five index anxiety disorders were recruited onto a longitudinal study in which they were interviewed every 6 months regarding symptoms, course, and treatments received. Of the five disorders studied, panic disorder without agoraphobia was the disorder most often found as a sole diagnosis and generalized anxiety disorder (GAD) was least often found alone, both as lifetime diagnoses or when restricted to cases active at intake. Panic disorder with agoraphobia and agoraphobia without history of panic disorder (AWOPD) had three specific diagnoses with which they were frequently comorbid: social phobia, simple phobia, and GAD. AWOPD, social phobia, and GAD were frequently found in the presence of each other. It is possible that the experience of anxiety due to any syndromal cause may decrease the threshold for an individual to experience other anxiety symptoms or disorders. Clinicians should be aware of these patterns of comorbidity in order to formulate accurate differential diagnoses and prescribe treatments in a rational manner.

Converting hydric cropland to wetland in Missouri: A geoeconomic analysis

ABSTRACT: A geographic information system (GIS) and enterprise budgets are used to identify hydric cropland sites in north-central Missouri that are suitable for conversion to wetlands and to evaluate the private and social economic feasibility of conversion. The GIS identifies hydric cropland sites meeting specific soils, size, and shape criteria. The soils criteria favor sites amenable to the development, maintenance, and productivity of a wetland. Sites smaller than 5 ha are eliminated because they are too smallfor wetland development. A shape factor is used to eliminate sites likely to have multiple owners, which complicates wetland development. Net social and net private economic benefits of converting hydric cropland to wetland are estimated for a range of benefits and costs. Two of the four cases examined indicated that conversion is socially feasible and one of the two cases analyzed indicated that conversion is privately feasible.

Temporal and Spatial Patterns of Breeding Brown-Headed Cowbirds in the Midwestern United States

Brown-headed Cowbirds (Molothrus ater) are an obligate brood parasite and a potential threat to some populations of migratory songbirds. I used radio-telemetry to study temporal patterns in behavior, habitat use, and sociality, as well as spatial patterns and movements among breeding, feeding, and roosting areas. I obtained a mean of 42 locations of 84 radio-tagged female cowbirds on three study sites in Illinois and Missouri. Radio-tagged females usually were located in forest and shrub-sapling habitats with a mean of 1.4 males during the morning breeding period. During midmorning to early afternoon, females commuted to short-grass, cropland, and feedlot habitats; they fed in small flocks. At dusk females roosted singly or in small groups near breeding or feeding areas, or commuted to a large communal roost. Behavior and time of day, behavior and habitat use, and habitat use and time of day were highly associated. For approximately 90% of the radio-tagged cowbirds, breeding, feeding, and roosting locations were distributed nonrandomly within home ranges, and came from distinct utilization distributions. Cowbirds moved an average of 3.6 km between roosting and breeding locations, 1.2 km between breeding and feeding locations, and 2.6 km between feeding and roosting locations. Midwestern cowbirds show the same pattern of commuting between disjunct breeding and feeding areas as elsewhere in their range.

Within-Tree Distribution of Phyllonorycter blancardella (F.) and P. crataegella (Clemens) (Lepidoptera: Gracillariidae) and Associated Levels of Parasitism in Commercial Apple Orchards

The within-tree distribution of Phyllonorycter blancardella (F.) and P. crataegella (Clemens) and the associated levels of parasitism in commercial apple orchards were examined for 2 years at two sites in west-central Missouri. Canopies of 10 trees at both sites were divided into three regions (or heights): upper, middle, and lower. Each region was further divided into within-row and between-row positions. Leaf and mine samples were taken at the end of every leafminer generation to determine mean leafminer density (mines/leaf) and percent parasitism. Neither the leafminers nor the parasitoids displayed a preference for either the within-row or between-row canopy positions of the tree. However, at both sites and years, the mean level of mines/leaf was generally greater in the lower-middle canopy regions of the tree. Conversely, parasitoid activity appeared to be more evenly distributed throughout the tree with a tendency for higher levels of parasitism to be found in the middle-upper canopy regions. Early-season monitoring of leafminer and parasitoid activity can be accurately determined with leaf samples gathered from the lower portion of the canopy.