Northern Arkansas Research Articles

A History of Southern Missouri and Northern Arkansas: Being an Account of the Early Settlements, the Civil War, the Ku-Klux, and Times of Peace

A History of Southern Missouri and Northern Arkansas: Being an Account of the Early Settlements, the Civil War, the Ku-Klux, and Times of Peace

Estimating Degradable Intake Protein in Warm- and Cool-Season Forages Grown on Producer Farms in Northern Arkansas

Two case studies were conducted on producer farms in northwest Arkansas to assess degradable intake protein (DIP) and undegradable intake protein (UIP) in forages grown throughout the region. In Case Study 1, DIP was greater (P<0.05) by 11.7 and 4.7 percentage units of CP and DM, respectively, for cool-season pastures compared with pastures dominated by warm-season grasses. For both photosynthetic types, NDF exhibited a strong negative correlation (r ≤ -0.61; P≤0.006) with DIP. Generally, both CP and in vitro OM disappearance (IVOMD) were strongly and positively correlated (r ≥ 0.67; P≤0.002) with DIP, but CP was not correlated with DIP (P>0.05) in warm-season pastures when DIP was expressed as a percentage of CP. In Case Study 2, N fertilization in April and July at two producer sites (Latta and Stephens) increased concentrations of CP for subsequent harvests in primarily linear (P<0.0001) patterns for bermudagrass [Cynodon dactylon (L.) Pers.] forages, but there was no residual effect (P>0.05) for a mid-summer (July 7) harvest that received no fertilization. In harvests immediately following fertilization, DIP increased; the linear term was significant (P≤0.004) in each case, but it was coupled with quadratic or cubic effects in some harvests. For the second harvest at each site, DIP was not affected (P>0.05) by residual effects of the initial application of N fertilizer in April. The size of the UIP pool also increased linearly (P≤0.002) immediately following N fertilization in three of four harvests, but the magnitude of these responses was small compared with those observed for DIP.

Incidence of Florida Largemouth Bass Alleles in Two Northern Arkansas Populations of Largemouth Bass, Micropterus salmoides Lacepede

Florida largemouth bass (Micropterus salmoides floridanus) have been intensively stocked throughout the southern United States for the past three to four decades due to perceived superior growth characteristics. As a result, introgression of Florida largemouth bass with native stocks of northern largemouth bass (M. s. salmoides) has been prevalent. Lakes Ashbaugh and SWEPCO, located in northern Arkansas, were both constructed near 1980 and initially stocked with Florida largemouth bass (LMB). Allele frequencies of three discriminant allozyme loci (sAAT-B, sIDH-B, sMDH-B) between Florida and northern largemouth bass were determined for LMB collected between 1994-1996. Florida largemouth bass alleles were common within each reservoir, yet more common in SWEPCO Lake, a cooling pond for a coal powered electric plant. FLMB allele frequencies in Lake Ashbaugh bass were 0.20 for sAAT-B*3-4 alleles, to 0.24 for sIDHP-B*2 and 0.27 for sMDH-B*2; SWEPCO Lake FLMB allele frequencies were highly variable, with 0.58 for s1DHP-B*2 alleles, 0.64 for sAAT-B*3-4 and 0.92 for sMDH-B*2. High incidence of Hardy- Weinberg disequilibrium was observed, indicative of genetic change within both populations. LMB alleles within the sMDH-B locus may be under selective pressure in SWEPCO Lake. Caution should prevail when introducing non- native stock into native gene complexes, as introduced genes persist through many generations.

A history of southern Missouri and northern Arkansas: being an account of the early settlements, the Civil War, the Ku-Klux, and times of peace

A History of Southern Missouri and Northern Arkansas: Being an Account of the Early Settlements, the Civil War, the Ku-Klux, and Times of Peace. By William Monks; edited and with an introduction by John F. Bradbury Jr. and Lou Wehmer. (Fayetteville: University of Arkansas Press, 2003. Pp. lxvii, 194. Series editor's preface by Daniel E. Sutherland, introduction, notes, map, illustrations, index. $29.95.) Guerrilla. Any Civil War scholar or buff can tell you what it means. With the notable exception of John Mosby's Virginians, guerrilla are usually understood to be irregular Confederate troops fighting under their own auspices, usually in less important areas of the war, like the transMississippi theater. Notable western guerrilla leaders included such men as William Quantrill, whose sack of Lawrence, Kansas, became the classic brutal attack on enemy civilians; George Todd, whose terrible revolver fighters used multiple, rapid-firing six-shooters to butcher Union soldiers armed with single-shot rifles; Bloody Bill Anderson, whose band staged the infamous Centralia Massacre, murdering unarmed Union soldiers going home on leave. Arch Clements, Jesse and Frank James, Cole Younger and his numerous brothers, the list goes on and on. These men made life in Arkansas, Missouri, Texas, and the Indian nations a true horror to pro-Union civilians and soldiers alike. But William Monks' memoir is about pro-Union guerrillas, and therein lies its importance and uniqueness. Part of the series Civil War in the West, compiled by the eminent regional historian Daniel Sutherland, Monks' book is a reprint of a 1907 volume. Edited and annotated masterfully by John F. Bradbury Jr. and Lou Wehmer, experts in the Civil War in Arkansas and Missouri, Monks' tale is one of a very few extant about a different type of guerrilla fighter, one who fought to keep the Union whole. His secessionist neighbors dismissed him as an ally of the lop-eared Dutch and nigger-lovers out of pro-Union St. Louis (p. 39). As with most memoirs written late in life, Monks steps lightly over many events that might harm his image, while treating those that reveal his opponents for what he thought them to be with more precision. One of the more fascinating sections of the book involves Monks' description of life in the Arkansas-Missouri border region before the Civil War. The emphasis on subsistence agriculture, herding and droving of wild hogs and cattle, and the abundance of wild game for hunting corresponds to the picture painted by local writers (John Wolf, Silas Turnbo, Theodore Russell) and to later descriptions of the nonslaveholding South in general by such historians as Grady McWhiney and Forrest McDonald. Also of interest is the roundabout way in which the Monks family arrived in the Ozark region from Alabama, circulating through Kentucky, Illinois, and Missouri, roughly paralleling the Cherokees' Trail of Tears. …

Surface Stream Occurrence and Updated Distribution of Allocrangonyx hubrichti Holsinger (Amphipoda: Allocrangonyctidae), an Endemic Subterranean Amphipod of the Interior Highlands

ABSTRACT Allocrangonyx hubrichti was previously known only from caves and springs in three counties in Missouri and from one well in northern Arkansas. During the development of biological criteria for the Missouri Water Quality Standards, from 1992 to 2002, 68 specimens were collected from 16 surface streams in 13 Missouri counties. Allocrangonyx hubrichti is now known from 25 sites in 15 counties in Missouri and Arkansas. The additional records constitute a significant range extension as well as documentation that A. hubrichti is a small but consistent component of surface fauna in some Interior Highlands streams.

Effects of Oak Decline on Species Composition in a Northern Arkansas Forest

Abstract Since 1999, widespread and locally severe oak decline and mortality have occurred throughout the Ozark Mountains of northern Arkansas and southern Missouri. A contributing factor in the decline and mortality is an outbreak of the red oak borer [Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae)]. In northern Arkansas, a 2,150 ac mature oak forest severely affected by decline was selected as a case study to describe changes in species composition and stand structure and to assess regeneration potential of oaks and non-oak species. Mortality reduced total overstory basal area from 105 to 57 ft2/ac, and overstory density decreased from 156 to 89 trees/ac. Most dead and dying trees were northern red oak (Quercus rubra L.) and black oak (Q. velutina Lam.). Basal area and density of overstory red oaks were reduced from 51 to 11 ft2/ac and from 60 to 11 trees/ac, respectively. These trees died regardless of dbh class. Mortality was less common in white oak (Q. alba L.) and was generally limited to smaller trees. Understory trees and taller seedlings were predominantly red maple (Acer rubrum L.), flowering dogwood (Cornus florida L.), blackgum (Nyssa sylvatica Marsh.), and black cherry (Prunus serotina Ehrh.). Oaks less than 3 ft tall were abundant, but taller oak seedlings and saplings were uncommon. Tree mortality increased the proportion of white oak and hickories (Carya spp.) in the overstory, and stimulated a regeneration response of mostly non-oak species. South. J. Appl. For. 27(4):264–268.

Tectonic controls of Mississippi Valley-type lead?zinc mineralization in orogenic forelands

Most of the world's Mississippi Valley-type (MVT) zinc–lead deposits occur in orogenic forelands. We examine tectonic aspects of foreland evolution as part of a broader study of why some forelands are rich in MVT deposits, whereas others are barren. The type of orogenic foreland (collisional versus Andean-type versus inversion-type) is not a first-order control, because each has MVT deposits (e.g., Northern Arkansas, Pine Point, and Cevennes, respectively). In some MVT districts (e.g., Tri-State and Central Tennessee), mineralization took place atop an orogenic forebulge, a low-amplitude (a few hundred meters), long-wavelength (100–200 km) swell formed by vertical loading of the foreland plate. In the foreland of the active Banda Arc collision zone, a discontinuous forebulge reveals some of the physiographic and geologic complexities of the forebulge environment, and the importance of sea level in determining whether or not a forebulge will emerge and thus be subject to erosion. In addition to those on extant forebulges, some MVT deposits occur immediately below unconformities that originated at a forebulge, only to be subsequently carried toward the orogen by the plate-tectonic conveyor (e.g., Daniel's Harbour and East Tennessee). Likewise, some deposits are located along syn-collisional, flexure-induced normal and strike-slip faults in collisional forelands (e.g., Northern Arkansas, Daniel's Harbour, and Tri-State districts). These findings reveal the importance of lithospheric flexure, and suggest a conceptual tectonic model that accounts for an important subset of MVT deposits—those in the forelands of collisional orogens. The MVT deposits occur both in flat-lying and in thrust-faulted strata; in the latter group, mineralization postdated thrusting in some instances (e.g., Picos de Europa) but may have predated thrusting in other cases (e.g., East Tennessee).

A land plant not a sponge: A re-evaluation of the Mississippian demosponge Vintonia and the family Vintoniidae

In 1956 two fossil specimens were exposed in concretions associated with two crushed body chambers of the orthoconic nautiloid Rayonnoceras sp. recovered from the Fayetteville Shale (Chesterian, upper Mississippian) of northern Arkansas. The two specimens were subsequently described as a new genus and species of demosponge, Vintonia doris Nitecki and Rigby and placed in the new family Vintoniidae (Nitecki and Rigby, 1966). The specimens were described as silicified. Nitecki and Rigby's analysis, based on the presence of an assumed skeletal net resembling the spongin net of Recent sponges, suggested that the specimens were demosponges with sycon structure. The “net” was considered spongin because of its geometric pattern and cellular appearance. That interpretation led to the placement of the specimens in the Order Keratosida despite the presence of an apparently well-developed ectosomal region, a feature that is not common in the Keratosida (Nitecki and Rigby, 1966).

A LAND PLANT NOT A SPONGE: A RE-EVALUATION OF THE MISSISSIPPIAN DEMOSPONGE VINTONIA AND THE FAMILY VINTONIIDAE

In 1956 two fossil specimens were exposed in concretions associated with two crushed body chambers of the orthoconic nautiloid Rayonnoceras sp. recovered from the Fayetteville Shale (Chesterian, upper Mississippian) of northern Arkansas. The two specimens were subsequently described as a new genus and species of demosponge, Vintonia doris Nitecki and Rigby and placed in the new family Vintoniidae (Nitecki and Rigby, 1966). The specimens were described as silicified. Nitecki and Rigby's analysis, based on the presence of an assumed skeletal net resembling the spongin net of Recent sponges, suggested that the specimens were demosponges with sycon structure. The “net” was considered spongin because of its geometric pattern and cellular appearance. That interpretation led to the placement of the specimens in the Order Keratosida despite the presence of an apparently well-developed ectosomal region, a feature that is not common in the Keratosida (Nitecki and Rigby, 1966).

Hill Folks: A History of Arkansas Ozarkers and Their Image

The Ozark region, located in northern Arkansas and southern Missouri, has long been the domain of the folklorist and the travel writer - a circumstance that has helped shroud its history in stereotype and misunderstanding. With Hill Folks, Brooks Blevins offers the first in-depth historical treatment of the Arkansas Ozarks. He traces the region's history from the early nineteenth century through the end of the twentieth century and, in the process, examines the creation and perpetuation of conflicting images of the area, mostly by outsiders. Covering a wide range of Ozark social life, Blevins examines the development of agriculture, the rise and fall of extractive industries, the settlement of the countryside and the decline of rural communities, in- and out-migration, and the emergence of the tourist industry. His richly textured account demonstrates that the Arkansas Ozark region has never been as monolithic or as homogenous as its chroniclers have suggested. From the earliest days of white settlement, Blevins says, distinct areas within the region have followed their own unique patterns of historical and socioeconomic development. Hill Folks sketches a portrait of a place far more nuanced than the timeless arcadia pictured on travel brochures or the backward and deliberately unprogressive region depicted in stereotype.

Effects of Stream Permanence on Crayfish Community Structure

Little is known regarding the impact of stream drying on community structure and habitat selection of lotic crayfish. Crayfish community structure was measured through quantitative sampling of riffle, run and pool habitats in 15 intermittent and 21 permanent streams in the Spring River watershed in the Ozark Plateau region of northern Arkansas and southern Missouri. MANOVA was used to determine whether stream permanence, habitat and crayfish size affect crayfish density and ANOVA was used to determine the effect of stream permanence and habitat type on species richness. Canonical Correspondence Analysis was used to determine the relationship between environmental variables and crayfish relative densities. Four crayfish species were collected: Orconectes marchandi, O. punctimanus, O. ozarkae and Cambarus hubbsi. Overall, crayfish densities were significantly greater in intermittent streams than in permanent streams with density of O. marchandi and O. punctimanus significantly greater in intermittent streams than in permanent streams. Densities of O. ozarkae and C. hubbsi did not differ significantly between the two stream types. Large individuals of O. punctimanus and O. ozarkae were found in significantly greater densities than small individuals. There was a significant relationship between crayfish relative density and abiotic environmental variables for permanent streams, but not for intermittent streams. In permanent streams, percent gravel, substrate diversity and mean current velocity were among the most important factors in determining crayfish density. Taxa mobility and predation risk are likely explanations for observed patterns of crayfish density.

Ontogeny and heterochrony in the Middle Carboniferous ammonoidArkanites relictus(Quinn, McCaleb, and Webb) from northern Arkansas

The reticuloceratid ammonoidArkanites relictus(Quinn, McCaleb, and Webb, 1962) is represented by hundreds to thousands of individuals from horizons isolated both stratigraphically and geographically in northern Arkansas. These assemblages appear to represent mass mortality events resulting from a semelparous reproductive strategy.Arkanites relictusoccurs as a dimorphic pair (depressed, widely umbilicate, cadiconic conchs and compressed, narrowly umbilicate, pachyconic conchs) thought to reflect sexual dimorphism. Late stage ontogenetic modifications, such as septal crowding and change in aperture profile, are widely cited evidence of sexual maturity in ammonoids. Septal crowding begins at a predictable ontogenetic stage in the compressed forms ofA. relictus,but specimens with cadiconic conchs do not have crowded septa even at the largest diameters available.Depending on the trait examined and the proxy for age of individuals, the dimorphism inArkanites relictus(using the depressed form as the reference morph) is the result of acceleration, neoteny, or hypermorphosis plus neoteny. If size (diameter) is considered a proxy for age, the dimorphs were the same age at death, and the septa in the compressed variants developed via acceleration relative to the depressed variants. Regarding conch shape (width vs. diameter), the compressed morphs developed via neoteny relative to the depressed morphs. If septal count is considered a proxy for age, the dimorphs were not the same age at death, and the compressed forms were produced by a combination of hypermorphosis plus neoteny, i.e., they grew longer yet slower than the depressed forms. InA. relictus,the heterochronic processes of hypermorphosis and neoteny may have been operating simultaneously, which is an interesting possibility because it is an example of a combination of both peramorphic and paedomorphic processes.

ONTOGENY AND HETEROCHRONY IN THE MIDDLE CARBONIFEROUS AMMONOID ARKANITES RELICTUS (QUINN, McCALEB, AND WEBB) FROM NORTHERN ARKANSAS

Abstract The reticuloceratid ammonoid Arkanites relictus (Quinn, McCaleb, and Webb, 1962) is represented by hundreds to thousands of individuals from horizons isolated both stratigraphically and geographically in northern Arkansas. These assemblages appear to represent mass mortality events resulting from a semelparous reproductive strategy. Arkanites relictus occurs as a dimorphic pair (depressed, widely umbilicate, cadiconic conchs and compressed, narrowly umbilicate, pachyconic conchs) thought to reflect sexual dimorphism. Late stage ontogenetic modifications, such as septal crowding and change in aperture profile, are widely cited evidence of sexual maturity in ammonoids. Septal crowding begins at a predictable ontogenetic stage in the compressed forms of A. relictus, but specimens with cadiconic conchs do not have crowded septa even at the largest diameters available. Depending on the trait examined and the proxy for age of individuals, the dimorphism in Arkanites relictus (using the depressed form a...

A Civil War Letter: Benjamin Fullager's Account of the Union Expedition against Van Buren

As 1862 DREW TO A CLOSE IN ARKANSAS, the military situation looked particularly bleak for Confederates in the Trans-Mississippi. Earlier that year, the state received its first taste of battle at Pea Ridge, where the Rebels were badly defeated by the Union army. The year also saw the Federals establish a presence in many areas of northern Arkansas. Union troops were able to garrison select towns and provide a certain sense of security to some of the populace. But in many parts of northern Arkansas there was near anarchy. The conflict quickly broke down what order existed in the area, and barbarism ruled the day for thousands of Arkansans. In December, the opposing armies met once again in northwest Arkansas, this time at Prairie Grove. The bruising slugfest that ensued was crippling for both sides, but the battle was especially devastating for the Confederates. The Rebel army virtually disintegrated, and the resulting catastrophe left the state open to further Federal conquest.1 Shortly after their victory at Prairie Grove, Union generals Francis J. Herron and James G. Blunt began planning their next move. They decided on an expedition against the Confederate garrison at Van Buren. However, poor weather prevented them from immediately moving against the town. The Union commanders met again on Christmas night and finalized their plans for the campaign. On the morning of December 27, 1862, the Federals moved out with 8,000 picked men and thirty pieces of artillery.2 Among the Union troops was Benjamin Fullager, a quartermaster sergeant of Company A, 3rd Wisconsin Cavalry. Born in London, England, Fullager heeded his adopted country's call for service and enlisted at Sparta, Wisconsin, on October 21, 1861. The twenty-six-year-old farmer joined for duty as a wagoner. He was promoted to quartermaster sergeant on October 20, 1862. Shortly before the close of the war he was promoted to the rank of captain and transferred to Company K of the unit.3 Fullager wrote home a few months after the expedition and described the events. His account of the campaign and his musings on army life provide great insight into the Civil War's impact on Arkansas.4 Also worthy of note is Fullager's candid discussion of Copperheads, as Confederate sympathizers in the North were known. His thoughts provide compelling evidence of the widespread disdain felt by many soldiers for those in their ranks who they suspected of being Copperheads. In fact his words border on the menacing. Fullager's contempt for some of his officers is indicative of the myriad of divisions that existed within the opposing sides, underscoring the complexity of the Civil War. Camp Salomon, MO5 March 14, 1863 Dear Friend Mary Your kind and welcome letter of Jan. 25 came to hand a day or two ago. I have been long looking for a word from you and scolded uncle Sam's mail arrangement a good deal for being so slow for I could not bring myself to think that the fault could be with you who has been so punctual heretofore and sure enough I was right for once. I am pleased to hear that you are having a pleasant time with your school but I hope you will not apply yourself so closely as to endanger your health for I do not think you owe enough to the rising generation to pay the debt by jeopardizing your own happiness but perhaps I am borrowing trouble on your account if so forgive me for I sin not intentionally in that case.6 Since writing you last I have been through many scene changes and vicisitudes incident to a soldiers life. Some pleasant and full of excitement, and some disagreeable and tending to depress our spirits and try our souls and health if not our patriotism. On the 27th of Dec. at the rather early hour of four in the morning our bugle's shrill notes sounded the reveille and soon after Boots and Saddles then the assembly and we soon found ourselves drawn up in line with three days rations in our haversacks ready to march we knew not where as yet, it might be to Mis. …

Geochemistry and tectonic setting of Paleoproterozoic metavolcanic rocks of the southern Front Range, lower Arkansas River Canyon and northern Wet Mountains, central Colorado

Across a 5000-km 2 area of central Colorado, previously unstudied Paleoproterozoic metabasalts (amphibolites) and metarhyolites (felsic gneisses) comprise a bimodal metavolcanic association within a dominantly metasedimentary terrain. Extending southward from about 39° N latitude in the Southern Front Range to about 38° 15′ N latitude in the Wet Mountains, and from the mountain front westward to the Wet Mountain Valley and Pleasant Valley fault system, this area includes the exceptional exposures within the lower Arkansas River Canyon from Howard downstream to Canon City. Regional metamorphism from garnet to sillimanite grade, pervasive deformation, and intrusion by three generations of Proterozoic plutons have largely obscured original stratigraphic relationships and primary structures within these metamorphic basement rocks, although a few pyroclastic features persist locally within the felsic members. These metavolcanic rocks are compositionally similar to the much better preserved bimodal section in the Salida area, dated at 1728 ± 6 Ma by Bickford (1986), which emerges from beneath Paleozoic cover rocks about 15 km beyond the western edge of the area of this report. Geochemical studies of 45 samples (30 amphibolites and 15 felsic gneisses) delineate two groups of metavolcanic rocks ranging in silica content from 45–55% in one group and from 65 to almost 80% in the other. Along a 100-km transect from north to south, metavolcanic rocks of the lower-silica group (amphibolites) show an increase in total alkalies (from 2% t o 5–6%) and large ion lithophile trace elements as well as an increase in degree of enrichment in light rare earth elements (from La N /Lu N N /Lu N ∼5). Rocks with higher silica content (felsic metavolcanic rocks) occur mostly in the Arkansas Canyon area and contain 6–8% total alkalies; they show strong fractionation between light and heavy rare earth elements with moderate to pronounced negative europium anomalies. Tectonic discriminant diagrams using relatively immobile high-field-strength elements indicate volcanic arc settings for both mafic and felsic populations. Metavolcanic rocks from the northern Wet Mountains and Arkansas Canyon suggest a mature arc environment, possibly on an expanding continental margin. The isolated metabasalts to the north in the southern Front Range, where no felsic metavolcanic rocks have been identified, are more primitive island-arc tholeiites; they may represent pyroclastic rocks with a source beyond the study area. These new data from a wide area of central Colorado reinforce results from the well-studied Paleoproterozoic bimodal are assemblages to the west near Salida and Gunnison. They also allow the extension across a wider geographic area of previous tectonic models for the Paleoproterozoic evolution of the Colorado province (as defined by Bickford et al., 1986). These models (Condie, 1986; Reed et al., 1987; Karlstrom et al., 1987) portray the rapid addition of juvenile crust to the southern margin of the Wyoming province by accretion of individual volcanic arcs or larger, previously amalgamated are terranes, resulting in the southward expansion of the craton by about 1300 km from 1800–1650 Ma.

Ruminal nitrogen disappearance from sod-seeded cereal grain forages in Northern Arkansas

Wheat (Triticum aestivum L.), oat (Avena sativa L.) and rye (Secale cereale L.) were overseeded into a dormant bermudagrass (Cynodon dactylon (L.) Pers.) sod and harvested on six dates throughout the spring. Plant growth stage was documented for each forage on each harvest date, and harvested forages were subsequently evaluated for forage quality characteristics. Four ruminally cannulated steers were used to evaluate disappearance kinetics of nitrogen (N) by an in situ method. All forages had high concentrations of N (≥31.1gkg−1DM) throughout harvest dates in March. By 15 April, rye had reached a substantially more advanced growth stage than either wheat or oat. This trait, coupled with the concurrent taller growth habit, caused concentrations of N in rye to decline (P<0.05) rapidly between the 24 March and 4 May harvest dates. The effective ruminal disappearance of N remained high (≥790gkg−1N) for all forages harvested through mid-April, thereby indicating that these cereal-grain forages exhibit the same characteristics of high N disappearance and low potential ruminal escape that are commonly observed in other high-quality cool season grasses harvested at similar growth stages. The effective disappearance of N reached a minimum (P<0.05) for all forages immediately before grain fill. Generally, substantial increases (P<0.05) in effective ruminal disappearance of N were observed as these forages partitioned N into the filling grain head. Fractional rates of N disappearance for wheat and rye were extremely rapid (≥0.383h−1) during grain fill. However, rye also exhibited an extremely rapid disappearance rate (0.548h−1) immediately prior to the onset of grain fill that was not observed for wheat (0.085h−1) at an identical growth stage. Parameters associated with disappearance kinetics can be related to growth stage at harvest by linear and polynomial regression techniques, although the best fit model was dependent on forage type.

Effect of Maturity on Degradation Kinetics of Sod-Seeded Cereal Grain Forage Grown in Northern Arkansas

Wheat (Triticum aestivum L.), oat (Avena sativa L.), and rye (Secale cereale L.) were overseeded into a dormant bermudagrass (Cynodon dactylon (L.) Pers.) sod and harvested at 3-wk intervals throughout March, April, May, and early June. Plant growth stage was documented for each forage on each harvest date, and harvested forages were evaluated for forage quality characteristics. Degradation kinetics of DM and NDF for these forages were evaluated by the in situ method. Fractional degradation rates for DM and NDF in all three species were relatively rapid for vegetative forage (≥0.086h –1) but declined rapidly by the heading stage of development and stabilized thereafter. Forage quality declined and forages were more resistant to ruminal degradation as plants entered the reproductive stages of growth. Based on these findings, growth stage is an effective predictor of most characteristics of in situ DM and NDF disappearance. The relationships between these degradation parameters and growth stage were typically explained with quadratic or cubic models. Clearly, forage quality characteristics of overseeded rye deteriorated more rapidly with phenological development and growth stage than quality characteristics of overseeded wheat and oat grown in the same environment. For rye, this problem is further complicated by its accelerated phenological development. These factors combine to permit a very narrow harvest window in early spring, relative to the other cereal grains evaluated. Acceptable forage quality may persist for an extended period in wheat and oat; this suggests that producers wishing to utilize these forages may lengthen the harvest window by planting more than one species, either as a mixture or preferably in independent stands.

Breeding Ecology and Behavior of Ozark Bass Ambloplites constellatus

Ozark bass (Ambloplites constellatus) are endemic to the White River drainage in northern Arkansas and southern Missouri. Although they are assumed to be similar to rock bass (A. rupestris), little is known of their behavior or life history. We investigated the spawning behavior and ecology of Ozark bass by snorkeling and seining in the Buffalo National River, Arkansas, from 1990–1992. Most males nested on gravel or cobble substrates. In 1992 65% of nests occurred within 1 m downstream of cover. Egg deposition was asynchronous, but began when water temperatures reached 17 C. Embryos hatched in 5 d at a mean water temperature of 21 C and free-embryos remained in their nests for up to 9 d before swim-up. Predation and high water limit Ozark bass spawning success in the Buffalo River. No nests in our study area successfully produced dispersing young in 1991, while 10% of nests monitored in 1992 were successful. Young-of-year were difficult for divers to locate during the day in 1990–1992 and were caught in seine hauls at night, but not during the day, suggesting that they may be nocturnal at this stage.

Genetic evidence for assortative mating between 13-year cicadas and sympatric "17-year cicadas with 13-year life cycles" provides support for allochronic speciation.

Thirteen-year cicadas of brood XIX from northern Arkansas, Missouri, and southern Illinois (lineage A) are known to be genetically different at two marker loci (mitochondrial DNA and abdominal color) from 13-year cicadas to the south (lineage B) that emerge in the same year. Because 17-year cicadas from all broods (year classes) are indistinguishable from lineage A at these two marker loci, previous workers suggested that the lineage A cicadas of 13-year brood XIX were derived from 17-year cicadas by life-cycle switching (allochrony). Data presented here show that, over the same northern geographic range, lineage A is also present in 13-year cicadas belonging to brood XXIII (which always emerges four years later than brood XIX). Detailed sampling along the putative life-cycle-switching boundary in 13-year brood XXIII revealed a previously unsuspected broad zone of overlap where populations contained individuals of both lineages A and B. Despite this sympatry, and previous reports of a lack of behavioral barriers to interbreeding, a strong correlation between mitochondrial haplotype and abdominal color suggests that assortative mating has taken place. Lineage A 13-year cicadas from both broods XIX and XXIII are only found within a gap in the spatial distribution of 17-year cicadas. This, in combination with the lack of differentiation between lineage A 13- and 17-year cicadas at the marker loci and new behavioral data for 13-year brood XIX, suggests a recent derivation of all northern 13-year cicadas from the 17-year cicadas via life-cycle switching. We discuss the implications of these allochronic shifts for speciation.

Coordinated strike-slip and normal faulting in the southern Ozark dome of northern Arkansas: Deformation in a late Paleozoic foreland

Coordinated strike-slip and normal faulting in the southern Ozark dome of northern Arkansas: Deformation in a late Paleozoic foreland