Allozyme variation in domesticated annual sunflower and its wild relatives

 The annual sunflower (Helianthus annuus L.) is a morphologically and genetically variable species composed of wild, weedy, and domesticated forms that are used for ornament, oilseed, and edible seeds. In this study, we evaluated genetic variation in 146 germplasm accessions of wild and domesticated sunflowers using allozyme analysis. Results from this survey showed that wild sunflower exhibits geographically structured genetic variation, as samples from the Great Plains region of the central United States were genetically divergent from accessions from California and the southwestern United States. Sunflower populations from the Great Plains harbored greater allelic diversity than did wild sunflower from the western United States. Comparison of genetic variability in wild and domesticated sunflower by principal coordinate analysis showed these groups to be genetically divergent, in large part due to differences in the frequency of common alleles. Neighbor-Joining analyses of domesticated H. annuus, wild H. annuus and two closely related wild species (H. argophyllus T. & G. and H. petiolaris Nutt.) showed that domesticated sunflowers form a genetically coherent group and that wild sunflowers from the Great Plains may include the most likely progenitor of domesticated sunflowers. Received: 2 December 1996/Accepted: 4 April 1997     

A Shoshonean Origin for the Plains Shield Bearing Warrior Motif

Abstract

The shield bearing warrior is a distinctive motif characteristic of the rock art of the Northwestern Plains. It also occurs commonly in the eastern Great Basin as an element of Fremont rock art. Detailed similarities between Plains and Great Basin shield figures suggest cultural relationships between the two areas. This has led some authors to propose that the motif originated in the Northwestern Plains and diffused to the Great Basin. Others argue that the motif spread from the Great Basin to the Plains. Relative dates recently obtained for shield figures at Northwestern Plains sites support the latter hypothesis. A Shoshonean origin for the Northwestern Plains shield figures is suggested by the dates, and the coincidence between the distribution of the motif, the distribution of diagnostic Shoshonean artifacts. and the ethnohistorically known range of the Plains Shoshone. It is suggested that the Shoshone borrowed the motif from the Fremont Culture during a period of interaction between the two groups.

The shield bearing warrior, a distinctive motif that depicts a pedestrian warrior whose body is represented by a large circular shield (Fig. 1), is frequently encountered in the rock art of the western United States. It is especially common at sites on the Northwestern Plains and in the eastern Great Basin (Fig. 2).     

Scapula Skin-Dressing And Fiber-Processing Tools

Abstract

Information from ethnographic and archaeological literature supports the interpretation that some bison scapula tools were used for dressing skins. Sim!lar scapula artifacts may have been used for processing bark fiber used in making cordage or weaving. References to possible scapula processing tools from the Plains Northwest Coast, Great Lakes Riverine Area, and the Southeast are summarized. Specimens made of deer and elk scapulae probably represent functionally similar tool types. These artifacts may be more common than the available reports on Plains sites indicate, and archaeologists should exercise care when identifying scapula tools. We cannot assume that all scapula artifacts represent hoes or hoe fragments.     

Mammalian beta diversity in the Great Basin, western USA: palaeontological data suggest deep origin of modern macroecological structure

Aim Recent work indicates that desert assemblages have elevated beta (β) diversity (between‐locality turnover of species composition). This study compares β diversities between the Great Basin and the Great Plains of the western USA over the last 17 Myr. Today, the Great Basin is a topographically diverse desert scrubland to woodland and the Great Plains are low‐relief temperate grassland, but 17 Ma they were more similar in topography, climate and land cover. A georeferenced database of mammal occurrences, complied from several sources, is used to test two hypotheses for the elevation of Great Basin β diversity: (1) that tectonic change of the topography has driven increased habitat packing in high‐ and low‐elevation habitats, and (2) that climatic cycling in the Pleistocene has driven faunas from neighbouring provinces to overlap in the region. Location The Great Basin of the USA, centred on Nevada, and the central Great Plains of the USA, centred on Nebraska. Methods Mammalian faunal lists compiled from published records and the records of many museums, available online, were partitioned into time‐slices ranging from the recent to 17 Myr old. Beta diversity was calculated for each time‐slice in two ways: multiplicative β diversity using first‐order jackknife richness, and additive beta diversity using Simpson's evenness. Results Beta diversity is elevated in Nevada relative to Nebraska today. Beta diversity has been higher in the Great Basin since the Pleistocene and possibly since the late Early Hemphillian (c. 7 Ma). Beta diversity in the Late Barstovian (c. 13.5 Ma) of the Great Plains was higher even than β diversity in the Great Basin of today. Main conclusions The elevated β diversity in the Hemphillian supports the tectonic change hypothesis. The patterns of β diversity in the Recent, Pleistocene and Hemphillian all suggest that local‐scale processes are important. The β diversity of the Late Barstovian Great Plains supports other studies indicating increased primary productivity or species packing.     

Chain Mall in Plains Archeology

Abstract

Beginning in the 1880s, chain mail fragments have been found subsurface at five archeological sites in the Central Plains. All were in association with native Indian materials assignable to the Great Bend aspect and datable to the earliest period of European contacts with Central Plains Village Indian communities in the mid-sixteenth century. Among the several types of mail fabric represented, none is inconsistent with a 16th century Spanish provenience. Possible sources from which these items may have reached the Indians by pillage, theft, or trade are considered.     

The Great Bend Aspect: A Multivariate Investigation Of Its Origins And Southern Plains Relationships

Abstract

The origins of the Great Bend aspect as well as its relations with a series of southern Plains sites are analyzed using ceramic attributes and multivariate statistics. Although the data is inadequate in certain areas the results suggest that in-situ development from earlier cultural groups is a more likely explanation than is a migration of peoples from the southern Plains.     

An Archaeological Bibliography:

Abstract

The bibliography contains 302 references to archaeological phenomena and investigations in the northern sector of the Great Plains Province and spans the period between 1840 and 1930. Much of the bibliography is annotated.     

Radiocarbon Dates from the Sutter Site,Northeastern Kansas

Abstract

Five radiocarbon dates from the deeply buried, preceramic Sutter site (14JN309) are evaluated. Its relative chronological position in late Plano times is substantiated by a cluster of dates at approximately 6000 B.C. Comments are made concerning the Great Plains hunting and gathering subsistence pattern.     

The Fremont Culture: Its Derivation and Ultimate Fate

Abstract

Aikens (1966) has proposed that Fremont-Promontory culture originated on the Northwestern Plains and representsan Athabascan migration into the Utah area at circa A. D. 500, their descendents, he suggests, were later forced back onto the Plains by the 12th century expansion of Shoshoneans from the Great Basin. He also proposes that FremontPromontory culture was ancestral to Dismal River culture. In this paper an alternative hypothesis is proposed, i.e., that Fremont and then Promontory cultures were sequential developments from an indigenous Utaztecan or proto-Utaztecan base and that there is no direct cultural relationship between theUtah cultures and the Dismal River aspect.     

The Mississippian Heartland and Its Plains Relationship*

Abstract

The Cahokia site near East St. Louis, Illinois, was a gateway on the northwestern frontier of the Mississippian heartland. Its exact relationship to other Middle Mississippi cultures and to cultures of the Plains and Upper Great Lakes ar ea is still not fully under stood. It is clear, nonetheless, that these relationships, when more completely known, will prove to be :inuch more complicated than any suggested in current literature.     

Fire tolerance of a resprouting <Emphasis Type="Italic">Artemisia</Emphasis> (Asteraceae) shrub

In North America, most Artemisia (Asteraceae) shrub species lack the ability to resprout after disturbances that remove aboveground biomass. We studied the response of one of the few resprouting Artemisia shrubs, Artemisia filifolia (sand sagebrush), to the effects of prescribed fires. We collected data on A. filifolia density and structural characteristics (height, canopy area, and canopy volume) in an A. filifolia shrubland in the southern Great Plains of North America. Our study sites included areas that had not been treated with prescribed fire, areas that had been treated with only one prescribed fire within the previous 5 years, and areas that had been treated with two prescribed fires within the previous 10 years. Our data were collected at time periods ranging from ½ to 5 years after the prescribed fires. Density of A. filifolia was not affected by one or two fires. Structural characteristics, although initially altered by prescribed fire, recovered to levels characteristic of unburned areas in 3–4 years after those fires. In contrast to most non-sprouting North American Artemisia shrub species, our research suggested that the resprouting A. filifolia is highly tolerant to the effects of fire.     

High Plains wheat mosaic virus: An enigmatic disease of wheat and corn causing the High Plains disease

Brief historyIn 1993, severe mosaic and necrosis symptoms were observed on corn (maize) and wheat from several Great Plains states of the USA. Based on the geographical location of infections, the disease was named High Plains disease and the causal agent was tentatively named High Plains virus. Subsequently, researchers renamed this virus as maize red stripe virus and wheat mosaic virus to represent the host and symptom phenotype of the virus. After sequencing the genome of the pathogen, the causal agent of High Plains disease was officially named as High Plains wheat mosaic virus. Hence, High Plains virus, maize red stripe virus, wheat mosaic virus, and High Plains wheat mosaic virus (HPWMoV) are synonyms for the causal agent of High Plains disease.TaxonomyHigh Plains wheat mosaic virus is one of the 21 definitive species in the genus Emaravirus in the family Fimoviridae.VirionThe genomic RNAs are encapsidated in thread‐like nucleocapsids in double‐membrane 80–200 nm spherical or ovoid virions.Genome characterizationThe HPWMoV genome consists of eight single‐stranded negative‐sense RNA segments encoding a single open reading frame (ORF) in each genomic RNA segment. RNA 1 is 6,981‐nucleotide (nt) long, coding for a 2,272 amino acid protein of RNA‐dependent RNA polymerase. RNA 2 is 2,211‐nt long and codes for a 667 amino acid glycoprotein precursor. RNA 3 has two variants of 1,439‐ and 1,441‐nt length that code for 286 and 289 amino acid nucleocapsid proteins, respectively. RNA 4 is 1,682‐nt long, coding for a 364 amino acid protein. RNA 5 and RNA 6 are 1,715‐ and 1,752‐nt long, respectively, and code for 478 and 492 amino acid proteins, respectively. RNA 7 and RNA 8 are 1,434‐ and 1,339‐nt long, code for 305 and 176 amino acid proteins, respectively.Biological propertiesHPWMoV can infect wheat, corn (maize), barley, rye brome, oat, rye, green foxtail, yellow foxtail, and foxtail barley. HPWMoV is transmitted by the wheat curl mite and through corn seed.Disease managementGenetic resistance against HPWMoV in wheat is not available, but most commercial corn hybrids are resistant while sweet corn varieties remain susceptible. Even though corn hybrids are resistant to virus, it still serves as a green bridge host that enables mites to carry the virus from corn to new crop wheat in the autumn. The main management strategy for High Plains disease in wheat relies on the management of green bridge hosts. Cultural practices such as avoiding early planting can be used to avoid mite buildup and virus infections.     

Exotic herbivores and fire energy drive standing herbaceous biomass but do not alter compositional patterns in a semiarid savanna ecosystem

Questions

Fire regime alterations are pushing open ecosystems worldwide past tipping points where alternative steady states characterized by woody dominance prevail. This reduces the frequency and intensity of surface fires, further limiting their effectiveness for controlling cover of woody plants. In addition, grazing pressure (exotic or native grazers) can reinforce woody encroachment by potentially reducing fine-fuel loads. We investigated the effects of different fire energies on the herbaceous plant community, together with mammalian wildlife herbivory (exotic and native combined) exclusion, to inform best management practices.

Location

Texas semi-arid savanna, southern Great Plains, USA.

Methods

We conducted an experiment in which we manipulated fire intensity and herbivore access to herbaceous biomass in a split-plot design. We altered fire energy via fuel addition rather than applying fire under different environmental conditions to control for differences in standing biomass and composition attributable to differential plant physiological status and fire season.

Results

High-energy fire did not reduce herbaceous biomass or alter plant community composition, although it did increase among-plot variability in composition and forb biomass relative to low-energy fire and non-burned controls. Grazing pressure from native and non-native mammalian herbivores reduced above-ground herbaceous biomass regardless of fire treatments, but did not alter community composition.

Conclusions

Managers seeking to apply high-intensity prescribed fire to reduce woody encroachment will not negatively impact herbaceous plant productivity or alter community composition. However, they should be cognizant that repeated fires necessary for greatly reducing woody plants in heavily invaded areas might be difficult to accomplish due to fine-fuel reduction from wild herbivores. High fencing to restrict access by wildlife herbivores or culling might be necessary to build fuels sufficient to conduct high-intensity burns for woody-plant reduction.     

Parasitism of the Wheat Stem Sawfly (Hymenoptera: Cephidae) in Montana

The wheat stem sawfly,Cephus cinctusNorton (Hymenoptera: Cephidae) was first found in wild grasses and soon became an economically important pest of wheat after cultivation began in the northern Great Plains. Of the species of parasitoids that attackC. cinctusin wild grasses, onlyBracon cephi(Gahan) andB. lissogasterMuesebeck (Hymenoptera: Braconidae) have been found in wheat. Levels of parasitism vary between wheat-producing regions in Montana. Parasitism levels were increased by releasing individuals from a region with high levels of parasitism into a region where parasitism levels were low. This suggests that there has been unequal rates of parasitoid adaptation from wild grasses to wheat in different regions of Montana.     

Notes on the White Earth Creek Site (32MN2)

Abstract

The White Earth Creek Site, partially excavated by Thad. C. Hecker in 1938, is important because of its location well north of most other fortified sites in the northern Great Plains. The site is also unusual in that it consists of a fortification without any indication of permanent structures within the ditch and palisade. Data collected by Hecker are discussed in terms of the contribution which they can make to our picture of North Dakota aboriginal life outside the main valley of the Missouri River.     

Recent decline of the critically endangered Plains‐wanderer (Pedionomus torquatus), and the application of a simple method for assessing its cause: major changes in grassland structure

A monitored population of the critically endangered Plains‐wanderer (Pedionomus torquatus) on Victoria's Northern Plains declined by over 90% between 2010 and 2012 following an unusually wet year which led to flooding, excess grass growth and a major change in the structure of native grasslands. The Plains‐wanderer population remained very low on private land during 2013 and 2014 when dry conditions prevailed and domestic stock overgrazed most of its favoured grasslands on red soil. Numbers also remained very low on public reserves despite grassland structure gradually improving there by 2014. In 2015, the population partially recovered in some grasslands protected from overgrazing. Grassland structure is critically important for Plains‐wanderer conservation. The ‘golf ball technique’ proved to be a quick and effective method for measuring grassland structure; it offers a means of accelerating responses to habitat change because it can be easily used by land managers.     

Bowers of the Great Bowerbird (Chlamydera nuchalis) remained unburned after fire: is this an adaptation to fire?

Fire plays an important role in the evolution of life-history characteristics of organisms living in fire-prone regions. Although there are many reports of plants exhibiting adaptations to reduce the harmful or lethal effects of fire, little is known about fire-resistance mechanisms among animals, other than fleeing responses. Here, we report observations that may represent a type of fire adaptation in a bird species: bowers in one population of the Great Bowerbird Chlamydera nuchalis remained unburned after fire. If a bower is destroyed by fire or other mechanisms during courtship and breeding season, the male may lose the opportunity to mate with females, thereby reducing his apparent fitness. Therefore, traits that minimise the damage to bowers from fires may be beneficial. By measuring the unburned areas surrounding bowers after fires, we showed that the survival of bowers after fires is unlikely to be solely related to chance. Our observations are consistent with the hypothesis that bower resistance to fire is an adaptation of the Great Bowerbird. However, it is also possible that unburned bowers are by-products of sexual selection.     

Plant water uptake by hard red winter wheat (Triticum aestivum L.) genotypes at 2°C and low light intensity

Background  

Hard red winter wheat (HRWW; Triticum aestivm L.) plants from genotypes selected in the Northern Great Plains of the U.S. have less tissue water after exposure to cool autumn temperatures than plants from the Southern Great Plains. It is generally assumed that the reduced tissue water content of northern compared to southern cultivars is due to an impedance to water uptake by northern plants as a result of the low autumn temperatures. We hypothesize that if low temperature impedes water uptake then less soil water would be removed by northern than by southern-selected cultivars. This hypothesis was tested by comparing plant water uptake of a northern (FR) and a southern (FS) cultivar in relation to their foliage water content at 2°C.     

Decadal heat and drought drive body size of North American bison (Bison bison) along the Great Plains

Large grazers are visible and valuable indicators of the effects of projected changes in temperature and drought on grasslands. The grasslands of the Great Plains have supported the greatest number of bison (Bison bison; Linnaeus, 1758) since prehistoric times. We tested the hypothesis that body mass (BM, kg) and asymptotic body mass (ABM, kg) of Bison decline with rising temperature and increasing drought over both temporal and spatial scales along the Great Plains. Temporally, we modeled the relationship of annual measures of BM and height (H, m) of 5,781 Bison at Wind Cave National Park (WICA) from 1966 to 2015. We used Gompertz equations of BM against age to estimate ABM in decadal cohorts; both females and males decreased from the 1960s to the 2010s. Male ABM was variable but consistently larger (699 vs. 441 kg) than female ABM. We used local mean decadal temperature (MDT) and local mean decadal Palmer Drought Severity Index (dPDSI) to model the effects of climate on ABM. Drought decreased ABM temporally (?16 kg/local dPDSI) at WICA. Spatially, we used photogrammetry to measure body height (H_E) of 773 Bison to estimate BM_E in 19 herds from Saskatchewan to Texas, including WICA. Drought also decreased ABM spatially (?16 kg/local dPDSI) along the Great Plains. Temperature decreased ABM both temporally at WICA (?115 kg/°C local MDT) and spatially (?1 kg/°C local MDT) along the Great Plains. Our data indicate that temperature and drought drive Bison ABM presumably by affecting seasonal mass gain. Bison body size is likely to decline over the next five decades throughout the Great Plains due to projected increases in temperatures and both the frequency and intensity of drought.     

The Late Prehistoric Human Ecology of Birch Creek Valley,Northeastern Oklahoma

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.