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Oklahoma mednet     
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The Keota site, in the Middle Pennsylvanian (Desmoinesian) Keota Sandstone Member, McAlester Formation (Krebs Group) of Haskell County, Oklahoma, yields an extensive ichnofossil assemblage of arthropod trackways, insect resting traces, arthropod feeding and grazing traces, fish swimming traces, and tetrapod footprints. This ichnofossil assemblage occurs in a 0.8 to 1.5-m-thick unit of thinly laminated and ripple-laminated sandstone at the base of the Keota Sandstone Member that is interpreted as a tidal flat sandstone. The arthropod traces are assigned to the ichnotaxa Diplichnites gouldi Gevers types A and B, Diplopodichnus biformis Brady, Paleohelcura tridactyla Gilmore, Tonganoxichnus buildexensis Mángano, Buatois, Maples and Lanier, Gordia marina Emmons, cf. Cochlichnus sp. and Treptichnus bifurcus Miller. The fish swimming traces are assigned to Undichna britannica Higgs, and the tetrapod tracks to Notalacerta ichnosp. and Pseudobradypus ichnosp. The Keota ichnofossil assemblage thus documents the first North American Pennsylvanian record of Paleohelcura tridactyla and the first record of Pseudobradypus from the western United States. This ichnofossil assemblage also provides compelling evidence of a freshwater habitat in a tidal flat setting during deposition of the fossil-bearing sandstone at the Keota site. Indeed, the Keota ichnofossil assemblage is characteristic of a Carboniferous-Permian Tonganoxichnus assemblage that identifies nonmarine tidal flat settings.  相似文献   

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Woody encroachment affects the biohydrology of rangelands worldwide and can increase evapotranspiration by increasing plant rooting depth, increasing the duration of the growing season, or by initiating a process of hydrologic recovery in formerly overgrazed landscapes. Eastern redcedar (Juniperus virginiana) is encroaching rapidly into rangelands in the Southern Great Plains of the USA, and beyond, including Oklahoma. However, the degree to which increasing growing season duration causes higher evapotranspiration after encroachment is not known. Here we show that increasing the duration of the growing season in north-central Oklahoma’s water-limited climate from seven months (April–October) to 12 months increases modeled evapotranspiration only marginally, from 95% to 97% of precipitation. However, this increase in evapotranspiration with woody encroachment into grassland corresponded to a two-thirds reduction in deep drainage. This study’s estimate of the hydrologic effects of eastern redcedar encroachment is likely to be highly conservative because it does not take into account the runoff-inducing effects of livestock grazing. Comparing simulated hydrologic fluxes in the present study to past work measuring runoff from grazinglands suggests that eastern redcedar encroachment into overgrazed rangelands is likely to increase evapotranspiration significantly. Whether or not eastern redcedar encroachment effects on evapotranspiration are discernable at the watershed scale will depend on the extent of encroachment throughout the watershed. Further research is necessary to quantify how the hydrologic effects of eastern redcedar encroachment vary due to climatic gradient.  相似文献   

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Few aerobiological studies have focused on smut spores, teliospores of fungi within the order Ustilaginales, but the scientific literature provides evidence of the potential aerobiological significance of these plant pathogens. The atmosphere in Tulsa, Oklahoma was monitored for the presence of smut teliospores using a Burkard Volumetric Spore Trap. Smut spores were identified in the atmospheric samples every day from May to October during 1991 and 1992 at concentrations that were normally below 1000 spores/m3. The peak concentration observed during this study was almost 6000 spores/m3. Daily concentrations fluctuate due to a variety of factors such as precipitation, relative humidity, percent sunshine, and the phenology of fungi in relation to their hosts. In northeastern Oklahoma, the most prevalent species of smuts in the atmosphere during the spring includeSphacelotheca occidentalis, Ustilago tritici, andU. kolleri. In the fall, spores ofU. brumivora, U. bullata, andU. maydis are more common.  相似文献   

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Few aerobiological studies have focused on smut spores, teliospores of fungi within the order Ustilaginales, but the scientific luterature provides evidence of the potential aerobiological significance of these plant pathogens. The atmosphere in Tulsa, Oklahoma was monitored for the presence of smut teliospores using a Burkard Volumetric Spore Trap. Smut spores were identified in the atmospheric samples every day from May to October during 1991 and 1992 at concentrations that were normally below 1000 spores/m3. The peak concentration observed during this study was almost 6000 spores/m3. Daily concentrations fluctuate due to a variety of factors such as precipitation, relative humidity, percent sunshine, and the phenology of fungi in relation to their hosts. In northeastern Oklahoma, the most prevalent species of smuts in the atmosphere during the spring includeSphacelotheca occidentalis, Ustilago tritici, andU. kolleri. In the fall, spores ofU. brumivora, U. bullata, andU. maydis are more common.  相似文献   

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ABSTRACT.   Mountain Plover ( Charadrius montanus ) populations are inefficiently sampled by Breeding Bird Surveys. As a result, targeted sampling of select populations of this species (with an estimated global population of 11,000–14,000 birds) can be valuable. Our objectives were to determine the breeding distribution and estimate the size of the Mountain Plover population in Oklahoma. We conducted a randomized point count survey in an area where Mountain Plovers were previously known to breed and conducted additional surveys over a larger area to better delimit the distribution. We used a removal model to estimate detection probability for raw counts obtained from 1104 point counts in 2004 and 2005, and derived a state-level population estimate using the detection-adjusted counts. Mountain Plovers used flat, bare, cultivated fields for nesting, and their distribution was closely tied to the presence of clay loam soils. We estimated that at least 68–91 Mountain Plovers bred in Oklahoma in 2004–2005. The low breeding density we observed may be due to the location of our study area near the southeastern edge of the breeding range of these plovers, the low-quality habitat provided by cultivated landscapes, or a combination of factors. Because the number of birds is small, the status of the Oklahoma population is not likely to have a large effect on the global population. However, additional information is needed to help determine if cultivated landscapes represented population sources or sinks.  相似文献   

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 Previous study of Cupressaceae pollen in the Tulsa atmosphere during December and January suggested that the source of this pollen is the Juniperus ashei (mountain cedar) populations that occur mainly in southern Oklahoma and central Texas. The present investigation examined the evidence of long-distance transport of pollen from these populations during the 1996/1997 season at three sites in Oklahoma using Burkard traps. Two of the pollen-monitoring stations were operated in conjunction with Mesonet meteorological stations. It was found that the December and January Cupressaceae pollen occurs outside of the local season at Tulsa. Pollen concentrations are intermittent and correspond to days of peak concentrations at sites nearer the mountain cedar populations. Peak concentrations are associated with winds coming from the south over the mountain cedar areas. Diurnal rhythms show night-time peaks with a delay in timing at the northern-most site. These results are all consistent with the hypothesis that pollen is being transported over long distances from the mountain cedar populations to Tulsa, Oklahoma. These findings are important as they represent one of the few incidences of long-distance transport of pollen in significant concentrations to an area where the source vegetation is not present. Pollen-monitoring sites located in conjunction with Mesonet meteorological stations provide a unique opportunity to further examine atmospheric conditions during long-distance transport events. This will aid future studies of the spatial modeling of long-distance dispersal of pollen. Received: 20 October 1997 / Revised: 24 June 1998 / Accepted: 26 June 1998  相似文献   

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Different spore types are abundant in the atmosphere depending on the weather conditions. Ascospores generally follow precipitation, while spore types such as Alternaria and Cladosporium are abundant in dry conditions. This project attempted to correlate fungal spore concentrations with meteorological data from Tulsa, Oklahoma during May 1998 and May 1999. Air samples were collected and analyzed by the 12-traverse method. The spore types included were Cladosporium, Alternaria, Epicoccum, Curvularia, Pithomyces, Drechslera, smut spores, ascospores, basidiospores, and other spores. Weather variables included precipitation levels, temperature, dew point, air pressure, wind speed, wind direction and wind gusts. There were over 242.57 mm of rainfall in May 1999 and only 64.01 mm in May 1998. The most abundant spore types during May 1998 and May 1999 were Cladosporium, ascospores, and basidiospores. Results showed that there were significant differences in the dry-air spora between May 1998 and May 1999. There were twice as many Cladosporium in May 1998 as in May 1999; both ascospores and basidiospores showed little change. Multiple regression analysis was used to determine which meteorological variables influenced spore concentrations. Results showed that there was no single model for all spore types. Different combinations of factors were predictors of concentration for the various fungi examined; however, temperature and dew point seemed to be the most important meteorological factors. Received: 5 July 2000 / Revised: 20 December 2000 / Accepted: 22 December 2000  相似文献   

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《Plains anthropologist》2013,58(85):207-238
Abstract

A multi-disciplinary study of the archaeological sites in Birch Creek Valley examined the valley’s paleoenvironment, prehistoric economy, and demography. The study indicates that during the Plains Village Period (ca. A.D. 800-1,500) the local environment was stable and similar to that of the area today with the valley being occupied during the late summer through winter by dispersed groups containing from 10 to 15 people. The Late Prehistoric occupants of the valley apparently relied on a broad-spectrum foraging economy and did not engage in horticulture.  相似文献   

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《Plains anthropologist》2013,58(74):279-282
Abstract

The unionid shells from the Goro Pit site (34CM131) were collected from the burned rock and shell concentrations and were subjected to burning. All of the unionid species and the one sphaerid species indicate that the local environment of 6000 B.P. was similar to that of the present. All of the species indicate the presence of perennial water.  相似文献   

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Oklahomaichnus millsii Sarjeant, from the Pennsylvanian (Missourian) Nellie Bly Formation of Oklahoma, is not the trackway of a lepospondyl amphibian, as originally proposed. Instead, it is the undertrack of an arthropod.  相似文献   

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In recent years, human tick‐borne disease occurrence has risen in Oklahoma, U.S.A., but year‐round data on tick presence in frequently used recreational areas is not widely available. In this study, ticks were collected monthly for one year at residential and non‐residential sites in a suburban area of Oklahoma County, OK, U.S.A. At each trapping site, dry ice traps were used in both woodland and grassland areas and fabric tick drags were used in grassland areas. Four species were collected from each park: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. Prior to this study, A. americanum was the only species with an established population in Oklahoma County. Consistent with this, A. americanum was collected in all months of the year and accounted for over 90% of ticks collected at each site. Based on our tick survey, we report that A. maculatum, D. variabilis, and I. scapularis, which were each collected in numbers greater than six within a single sampling occasion, are now each confirmed as established populations in Oklahoma County.  相似文献   

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In a recent survey in Oklahoma (USA), 52 free-ranging coyotes were examined for the presence of sarcocysts. Two of these coyotes were found infected with sarcocysts in skeletal muscle. By light microscopy, the cyst wall was thin and smooth. Ultrastructurally, the cyst wall had minute villar protrusions. The sarcocysts were 14.4 to 50.4 microm wide and 46.8 to 99 microm long. This is the first report of Sarcocystis sp. sarcocysts in the skeletal muscle of coyotes.  相似文献   

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Mycoflora of developing peanut pods in Oklahoma   总被引:1,自引:0,他引:1  
Starr and Argentine peanut cultivars were grown in soil fungicide treated irrigated and non-irrigated plots in a 2 year study designed to determine possible differences in invasion of developing seed pods byAspergillus flavus and other mycoflora. Many genera and species were isolated from whole pods and half shells throughout each season. Fungi were seldom isolated from kernels. No significant differences in populations between fungicide treatments, irrigation, or cultivars were found. Significant shifts in frequency of isolation of dominant genera (Fusarium andPenicillium) occurred during 1965 and 1966.Trichoderma viride, a minor component of the population at the first sampling in 1966, became a sub-dominant member by the last sampling. The reverse was true withA. niger. Several species of fungi, never before reported as occurring in peanut pods, were found in pods in this study:Actinomucor elegans, A. sclerotiorum, Sordaria fimicola, S. humana, andSporormia australis.Journal Article No. 1914, Oklahoma State University, Agricultural Experiment Station, Stillwater, Oklahoma.  相似文献   

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