Republican River Research Articles

Measurement of streambed hydraulic conductivity and its anisotropy

A method is described for the measurement of streambed hydraulic conductivity. Unlike permeameter methods, this method applies straight and l-shaped standpipes directly to streambeds for measurements of in-situ hydraulic conductivity in the vertical (K v ) and horizontal (K h ) directions, as well as in other oblique directions (K s ). This method has advantages in determination of K v values over grain-size analysis, permeameter tests, or slug test methods. Also unique to this method is that it provides K s values of a streambed. The measured results can be used to construct a hydraulic conductivity ellipse and to evaluate the anisotropy of streambed sediments. Field examples from the Republican River, Nebraska, demonstrated the usefulness of this method in the determination of streambed hydraulic conductivity and anisotropy along or across a river channel. Results indicate that the K h is about three to four times larger than K v , whereas K s values are larger than K v but smaller than K h .

Methodology and application of combined watershed and ground-water models in Kansas

Increased irrigation in Kansas and other regions during the last several decades has caused serious water depletion, making the development of comprehensive strategies and tools to resolve such problems increasingly important. This paper makes the case for an intermediate complexity, quasi-distributed, comprehensive, large-watershed model, which falls between the fully distributed, physically based hydrological modeling system of the type of the SHE model and the lumped, conceptual rainfall-runoff modeling system of the type of the Stanford watershed model. This is achieved by integrating the quasi-distributed watershed model SWAT with the fully-distributed ground-water model MODFLOW. The advantage of this approach is the appreciably smaller input data requirements and the use of readily available data (compared to the fully distributed, physically based models), the statistical handling of watershed heterogeneities by employing the hydrologic-response-unit concept, and the significantly increased flexibility in handling stream–aquifer interactions, distributed well withdrawals, and multiple land uses. The mechanics of integrating the component watershed and ground-water models are outlined, and three real-world management applications of the integrated model from Kansas are briefly presented. Three different aspects of the integrated model are emphasized: (1) management applications of a Decision Support System for the integrated model (Rattlesnake Creek subbasin); (2) alternative conceptual models of spatial heterogeneity related to the presence or absence of an underlying aquifer with shallow or deep water table (Lower Republican River basin); and (3) the general nature of the integrated model linkage by employing a watershed simulator other than SWAT (Wet Walnut Creek basin). These applications demonstrate the practicality and versatility of this relatively simple and conceptually clear approach, making public acceptance of the integrated watershed modeling system much easier. This approach also enhances model calibration and thus the reliability of model results.

Can Storage Coefficient Be Neglected in the Estimation of Unconfined Aquifer Parameters?

Unlike the Neuman solution (1974), the Dagan solution (1967) neglects elastic storage of unconfined aquifers. Whereas theformer has been commonly used in the analysis of aquifer pumpingtests, application of the latter to determination of aquiferparameters are rare. This article evaluates the reliabilityof the Dagan solution (1967) for the determination of the horizontaland vertical hydraulic conductivity Kr and Kz and specific yieldSy by neglecting the role of aquifer storage coefficient S.To be consistent in the analysis of aquifer test data, the Dagansolution was combined with an inverse computational procedureso that Kr, Kz, and Sy can be automatically calculated. Computationsconverge relatively fast because evaluation of the Dagan solutionis mathematically simpler than is the Neuman solution. Datafrom three pumping tests conducted in alluvial aquifers in thePlatte and Republican River valleys, Nebraska, were analyzed.Earlytime drawdown data from the site in the Platte River valleyare scarce, but plenty of early-time drawdowns were collectedfrom the two sites in the Republican River valley. Comparisonof the results from the Dagan and the Neuman solution indicatesthat the Dagan solution provides aquifer parameter values veryclose to those of the Neuman solution in most situations. Formost practical purposes, the Dagan solution is as good as theNeuman solution for aquifer test analysis.

Hydraulic Properties and Uncertainty Analysis for an Unconfined Alluvial Aquifer

AbstractAn inverse computational method was used to analyze pumping and recovery tests conducted in an unconfined alluvial aquifer along the Republican River valley in Nebraska. At each test site, a high‐capacity irrigation well was used as a pumping well, and eight observation wells were constructed to measure drawdown during the pumping and recovery tests. The test data were analyzed for four hydraulic parameters: the vertical (K z) and the radial (K r) hydraulic conductivity, the storage coefficient (S), and specific yield (S y). This method provides not only the average values but also estimated standard errors, confidence intervals, and correlation for the aquifer parameters. The standard error and confidence interval indicate the quality of the parameter estimates, and the correlation coefficients are useful in the evaluation of the relationship among the four parameters. High pumping rates seemed to reduce the effects of well borehole storage on drawdown. Because of the significant amount of early‐time data collected, the tests gave high‐quality S values. K r values for most observation locations range from 90 to 120 m/d. It was found that K r and S y had a higher correlation and the ratio of K r/K z varied from approximately 10 to 30.

Development of a Comprehensive Watershed Model Applied to Study Stream Yield under Drought Conditions

AbstractWe developed a model code to simulate a watershed's hydrology and the hydraulic response of an interconnected stream‐aquifer system, and applied the model code to the Lower Republican River Basin in Kansas. The model code links two well‐known computer programs: MODFLOW (modular 3‐D flow model), which simulates ground water flow and stream‐aquifer interaction; and SWAT (soil water assessment tool), a soil water budget simulator for an agricultural watershed. SWAT represents a basin as a collection of subbasins in terms of soil, land use, and weather data, and simulates each subbasin on a daily basis to determine runoff, percolation, evaporation, irrigation, pond seepage, and crop growth. Because SWAT applies a lumped hydrologic model to each sub‐basin, spatial heterogeneities with respect to factors such as soil type and land use are not resolved geographically, but can instead be represented statistically. For the Republican River Basin model, each combination of six soil types and three land uses, referred to as a hydrologic response unit (HRU), was simulated with a separate execution of SWAT. A spatially weighted average was then taken over these results for each hydrologic flux and time step by a separate program, SWBAVG. We wrote a package for MODFLOW to associate each subbasin with a subset of aquifer grid cells and stream reaches, and to distribute the hydrologic fluxes given for each subbasin by SWAT and SWBAVG over MODFLOW's stream‐aquifer grid to represent tributary flow, surface and ground water diversions, ground water recharge, and evapotranspiration from ground water. The Lower Republican River Basin model was calibrated with respect to measured ground water levels, streamflow, and reported irrigation water use. The model was used to examine the relative contributions of stream yield components and the impact on stream yield and base flow of administrative measures to restrict irrigation water use during droughts. Model results indicate that tributary flow is the dominant component of stream yield and that reduction of irrigation water use produces a corresponding increase in base flow and stream yield. However, the increase in stream yield resulting from reduced water use does not appear to be of sufficient magnitude to restore minimum desirable streamflows.

Effects of a Large Kansas Reservoir on Downstream Groundwater Quality

ABSTRACT Several water quality parameters, including inorganic nitrogens and phosphorus, were measured in groundwater from the Republican River aquifer above and below Milford Reservoir, Kansas. Ammonia and total phosphorus concentrations were considerably higher (>50%) in groundwater from the pressure relief wells along the toe of Milford Reservoir dam than from well water sampled upstream of the lake. However, the concentration of these compounds decreased to near upstream levels within 1.2 km downstream of the dam. Within the array of pressure relief wells, the concentration of ammonia was greatest in water from wells near the center of the dam. Conductivity, hardness, and alkalinity were lower, and pH was higher, in groundwater below Milford Reservoir than above it. The ratio of ammonia to total inorganic nitrogen in elutriates from Milford Reservoir sediments and water from the pressure relief wells was similar. These results suggest that water seeping out of reservoirs into underlying alluvial aquifers can leach soluble compounds, which exist in reservoir sediments, into the groundwater.

Temporal and environmental resolution of a buried loessal pedostratigraphic unit in Kansas and Nebraska

A loess/soil section near the Republican River in northeastern Kansas includes three superposed soils/paleosols in at least three superposed loess units, including Peoria Loess (PL), the Gilman Canyon Formation (GCF), and Loveland Loess (LL), The GCF coincides with a composite soil with a 1.3 m thick, buried organic-rich (A) horizon that yields AMS radiocarbon ages from 30.3 to 22.4 ka (or 35.7 to 26.9 ka when calibrated) that overlies a 1.6 m oxidized B horizon complex. The B subhorizons stratigraphically and morphologically resemble the “reddish pedocomplex” described elsewhere in Kansas and Illinois that dates between about 69 and 35 ka. The upper LL yields a TL age of about 136 and 130 + 30 ka. Thus, PL, the GCF, and LL were probably deposited mainly during the late Wisconsinan, middle Wisconsinan, and Illinoian (∼ Oxygen Isotope Stages (OIS) 2, 3, and 6, or about 12 to 24, 24 to 60, and 130 to 188 ka, respectively). Soils 1, 2, and 3, then formed mainly during OIS stages 1, 3, and 5, respectively, or about 12 to 12, 60 to 60, and 73 to 130 ka.In comparison with other dated stratigraphic sections in the Great Plains, soils/paleosols have relatively simple, cumulic horizon sequences, as is typical at sites distal from principle loess source regions. Nonetheless, they record a complex pedosedimentary history that reflects climatically-driven variations in rates of sedimentation and pedogenesis. Soil 1 is an Udic Argiustoll with 21-cm A (mollic)/69-cm Bt (argillic)/60-cm Bk horizons, that formed under modern-type grassland and climate. Soil 3, the Sangamon paleosol, includes a 3-m thick, highly rubified and clay-rich argillic horizon that, based on its morphological properties, probably formed under a relatively warm, moist, equable climate and deciduous-type forest. Soil 2 coincides with the GCF, and as such is a pedolithostratigraphic unit that includes a 1.3-m mollic horizon and to 1.6-m oxidized 3Btb and 3BCb horizons. Whereas the oxidized B horizons apparently represent relatively warm, moist climatic conditions between about 65 to 35 ka, the upper cumulic (mollic) A horizons of the GCF probably formed under progressively cooling climate and grassland between about 35.7 and 26.9 (calibrated radiocarbon) ka. Estimated mean accumulation rates (MARs) of loess range from 0.12 m/k yr for the GCF to about 0.5 m/k yr for PL.

The Battle of Beecher Island and the Indian War of 1867-1869

The way historians relate stories about Indian wars reveals a great deal about temper of their time. For many decades Anglos who chronicled Battle of Beecher Island presented episode as an example of white heroism and Indian perfidy. More recent renderings reversed hero and villain roles with Indians as righteous ones and whites rogues. Now, in The Battle of Beecher Island and Indian War of I867-i869, John H. Monnett joins a new generation of Indian wars scholars who break mold. He makes clear at outset he does not seek to judge conflict's antagonists but rather to understand events by integrating all points of view. Noting that both Indian and Anglo committed depredations during this period, Monnett concludes that the war was not a conflict of a 'good' society versus an 'evil' society; it was a clash of totally visions for future (I99). The first half of volume, which sets stage for dramatic tale of Beecher Island, offers familiar narrative of U.S. government's final push for Indian lands. In this particular case, Anglos moving west from Kansas settlements and others moving east from Colorado Rockies constricted Cheyenne, Arapaho, and Sioux, with railroads, state and territorial governments, and private land companies supporting settlers. On other side, Cheyenne Dog Soldiers led native holdouts who refused to surrender their claim on western Kansas and eastern Colorado. Army assaults on Indian camps, and Indian attacks on settlers, railroad workers, and stage stations culminated in a spiraling escalation of violence. Monnett emphasizes mutual brutality, committed by uncompromising ones in both cultures (65). Anxious to quiet concerns of frontier interests regarding Indian attacks, Philip Sheridan organized Scouts, a so-called crack team of settlers designed to pursue Indian raiders quickly and prevent further assaults. Concerned about brutality as well as negative publicity garnered by Colorado's Volunteers at Sand Creek several years before, Sheridan placed scouts under command of army regulars, Major George A. Forsyth and Lieutenant Frederick Beecher. On 17 September i868, while Forsyth's Scouts patrolled plains, Cheyenne and Sioux attacked them. Approximately fifty scouts sought refuge on an island in Republican River's Arickaree Fork and with34I

Radiocarbon Ages of Soils and Charcoal in Late Wisconsinan Loess, South-Central Nebraska

The Farmdale Soil occurs below late Wisconsinan loess throughout the U.S. Midwest. At the La Sena site in the central Great Plains, humates in the Farmdale Interstadial Soil have a corrected age of 21,000 yr B.P. Humates in a buried Bt horizon and a bulk sample of overlying loess 2.5 m above the Farmdale Interstadial Soil have ages of 17,000 and 19,000 yr B.P., respectively. In the Republican River Valley Picea (spruce) charcoal is common in the lower meter of Peoria loess. Near Bloomington, Nebraska, humates from burned organic matter only 60 cm above the base of Peoria loess have a corrected age of ca. 19,000 yr B.P.

Late Holocene alluvial chronology and climate change in the central great plains

Alluvium in one reach of the Republican River valley, south-central Nebraska, dates to the Holocene. Radiocarbon dating of fills underlying the two terraces in the valley reveals that entrenchment between 4500 and 3700 yr B.P. formed the high terrace. Subsequently, alternating aggradation and stability occurred until sometime between 1800 and 1100 yr B.P. Following another period of alluviation, channel incision formed the low terrace. General synchrony between this chronology and other late Holocene fluvial chronologies of the central Great Plains suggests climatic control of fluvial activity. The episodes of incision are tentatively correlated with different climate regimes, illustrating the difficulty of attributing a given fluvial response to a particular direction of climatic change.

THE RESPONSE OF FLUVIAL SYSTEMS TO CLIMATE CHANGE: AN EXAMPLE FROM THE CENTRAL GREAT PLAINS

A late Holocene alluvial chronology for a reach of the Republican River, south-central Nebraska, and the late Holocene alluvial and paleoclimatic records of the central Great Plains illustrate the problems inherent in relating fluvial activity to climate change. The alluvial and climatic records reveal that areally synchronous incision around 4200 yr B.P. correlated with a shift to more mesic climatic conditions. Areally synchronous incision after 1100 yr B.P. cannot be correlated to a climate change, primarily because paleoclimatic data for that period are lacking. The dissimilar temporal resolutions of the alluvial and paleoclimatic records hinder attempts to generalize the response of fluvial systems to climate changes. Over relatively long (hundreds of years) and short (tens of years) time scales, the fluvial response to climatic shifts is dependent on variables that may not be discernible in the paleoclimatic record. To enhance understanding of the reaction of fluvial systems to climate change in the...

A County That Has Gone Downhill

This is a survey of population declines in the central Great Plains region of the United States in general and a detailed analysis of spatial variations in depopulation in one county. Population growth bypassed large portions of the central Great Plains during the 1970s. Counties without large central places or access to interstate highways continued to lose population. Examination of conditions in the Republican River valley and in Furnas County Nebraska illustrates how open-country population decline was especially severe in areas of upland terrain. (EXCERPT)

Recent Surveys of Fishes from Western Kansas

Twenty-four species of fishes are reported from qualitative surveys of rarely collected streams in the Republican River basin of Cheyenne County, the Smoky Hill River system of Wallace County, the Salt Fork Arkansas River drainage of Barber and Comanche counties, and a pond in the Saline River basin of Trego County in Kansas. Special reference is made to protected species in Kansas, distributional records, and future considerations. Few comprehensive surveys of the fishes from streams in western Kansas have been conducted and reported in the literature. Surveys by personnel of the Kansas Department of Wildlife and Parks (Kansas Fish & Game Comm., 1977, 1978, 1979a, 1979b) provide most of the recent information available for the stream systems included here, but there were a limited number of collection sites in some drainages and voucher specimens are lacking. In addition to these studies, Cross et al. (1985) thoroughly summarized the known collections from the Arkansas River and its tributaries. General compilations of previous collections from the areas of western Kansas sampled by us in 1986-1988 can be found in Cross (1967), Cross and Collins (1975), and supplements by Collins and Caldwell (1978) and Collins (1981). From 1986 through 1988, qualitative surveys of fishes were conducted from six sites in the Upper Republican River drainage of Cheyenne County, three sites in the Smoky Hill River drainage of Wallace County, ten sites in the Salt Fork Arkansas River drainage of Barber and Comanche counties, and one site in the Saline River basin of Trego County (Fig. 1). MATERIALS AND METHODS Collections were made with single-panel seines of several lengths with 6.49.5 mm ace mesh and a 14 m bag seine with 6 m panels (9.5 mm mesh) This content downloaded from 157.55.39.224 on Sat, 27 Aug 2016 06:06:36 UTC All use subject to http://about.jstor.org/terms Arikaree R. Saline R. Pond* WaKeeney Cherry Cr. El St. F ancis Ellis

Central Plains Prehistory: Holocene Environments and Culture Change in the Republican River Basin

Central Plains Prehistory: Holocene Environments and Culture Change in the Republican River Basin

Archeology of the Midwest: Central Plains Prehistory . Holocene Environments and Culture Change in the Republican River Basin. Waldo R. Wedel. University of Nebraska Press, Lincoln, 1986. xviii, 280 pp., illus. $34.50.

Archeology of the Midwest: <i>Central Plains Prehistory</i> . Holocene Environments and Culture Change in the Republican River Basin. Waldo R. Wedel. University of Nebraska Press, Lincoln, 1986. xviii, 280 pp., illus. $34.50.

The Way of the Animal Powers: Volume One of 'Historical Atlas of World Mythology'; The Prehistory of Korea; Prehistoric Diets; In Search of the Dark Ages; Economy, Society &amp; Warfare Among the Britons &amp; Saxons; In the Name of Eugenics; Foundations of Nonverbal Communication; The Future of Pastoral Peoples; Central Plains Prehistory: Holocene Environments and Culture Change in the Republican

The Way of the Animal Powers: Volume One of 'Historical Atlas of World Mythology'; The Prehistory of Korea; Prehistoric Diets; In Search of the Dark Ages; Economy, Society &amp; Warfare Among the Britons &amp; Saxons; In the Name of Eugenics; Foundations of Nonverbal Communication; The Future of Pastoral Peoples; Central Plains Prehistory: Holocene Environments and Culture Change in the Republican

Growth of Pylodictus olivaris (Rafinesque) in a Kansas Reservoir

Spine sections were taken from pectoral spines secured from 200 flathead catfish collected from Milford Reservoir during 1975. Age determination was accomplished with the aid of a microprojector and comparison to spine sections taken from dorsal spines. The y-intercept of the body length-pectoral spine relationship was incorporated into a direct proportionality formula for back-calculating length at annulus formation. Length-weight relationships and condition factors were also computed for males, females, and the two sexes combined. Weights were back-calculated at annulus formation based on back-calculated lengths utilizing the length-weight relationship derived from empirical data. 1979. Age and growth studies of flathead catfish in Kansas have for the most part been restricted to riverine environments. Cross and Hastings (1956) reported concerning the ages of twenty-nine flathead catfish collected from the Kansas River. Minckley and Deacon (1959) determined growth rates of flathead catfish from the Big Blue River and the Neosho River. Other studies have been compiled on age and growth of flathead catfish collected in Oklahoma waters (McCoy, 1953; Jenkins, 1952). In most of these studies, a direct proportion was assumed in the body length-pectoral spine relationship. The y-intercept was assumed in most cases to be zero. A secondary purpose of this study was to document age and growth of flathead catfish in a large Kansas Reservoir. A food habit study was also completed in relationship to age and growth and is to be the topic of another publication. All specimens utilized for this study were collected from Milford Reservoir above the town of Milford, Kansas. Milford Reservoir was constructed by the U.S. Army Corps of Engineers as a flood control impoundment and water was first impounded in 1967. The dam is located four miles northwest of Junction City, Kansas, on the Republican River. Milford Reservoir, at conservation level, has a surface area This content downloaded from 207.46.13.128 on Tue, 06 Sep 2016 05:40:10 UTC All use subject to http://about.jstor.org/terms

Recent Records of the River Otter from Nebraska

The river otter (Lutra canadensis) once was common along waterways in Nebraska (Jones, 1964), but evidently was extirpated from the state in the early part of this century. Pressure from trapping, pollution of streams, and destruction of original stream-side habitats . .. were some of the reasons thought to have contributed to the demise of the otter in Nebraska according to Jones (1964). The most recently taken specimen examined by him from the state was obtained in 1916, although Bowles (1975) reported a specimen that was obtained in the Missouri River drainage in western lowa in 1929. On 7 November 1977, a raccoon trapper took a female otter in a steel trap near Sappa Creek, a tributary of the Republican River, at a place 61/2 mi. S and 41/2 mi. W Beaver City, Furnas County, Nebraska. The animal, which was in good condition, weighed 18.6 pounds and had a total length of 46 inches. It currently is in the possession of the Nebraska Game and Parks Commission. Ralph Velich, a commercial taxidermist in Omaha, reported to us (pers. comm.) that an otter of unknown sex was killed on 18 December 1964 by dogs of a hunter in pursuit of raccoons along the south bank of the Platte River, not far from its confluence with the Missouri, 4 mi. W Louisville, Cass County, Nebraska. The tanned and stretched skin of this specimen measured 52 inches in length according to Velich. It is noteworthy, too, that Bowles (1975) reported a specimen taken in 1969 near Council Bluffs, lowa, just across the Missouri River from Nebraska, and considered that L. canadensis had redestablished itself along the southern part of the Missouri in that state. No doubt the Misouri River has been the avenue for recent dispersal of otters to eastern Nebraska and probably also for individuals that now may occur in other parts of the state (all river systems in Nebraska ultimately reach the Missouri). It is doubtful that otters recently transplanted in the mountains of Colorado by the Colorado Department of Game and Fish would emig rate to Nebraska, but the potentiality for them to do so does exist along the South Platte River and its tributaries. In any event, the records reported here and persistent reports of obser\/ations of otters elsewhere in eastern Nebraska and adjacent lowa suggest that the species currently is reinvading at least part of its former range in this region.

Acanthocephala of Nebraska Fishes

Between April 1971 and August 1974, 2425 fishes representing 17 families and 57 species were collected from 71 sites throughout Nebraska and examined for acanthocephalans. Two hundred eighty-two (11.6%) of the fishes were infected. Except for an incidental mention of Tanaorhamphus longirostris, there is no previously published report of Acanthocephala in Nebraska's fishes. Nine species, Leptorhynchoides thecatus, Neoechinorhynchus cristatus, N. cylindratus, N. prolixus N. rutili, Octospinifer macilentus, Paulisentis missouriensis, Pomphorhynchus bulbocolli and 7anaorhamphus longirostris, are now known to occur. Neoechinorhynchus cylindratus is reported for the first time from Esox vermiculatus and Ictalurus melas and Tanaorhamphus longirostris for the first time from Carpiodes carpio and Morone chrysops, but all specimens of both parasite species were immature. Pomphorhynchus bulbo,colli is reported for the first time from E. vermiculatus, Hybopsis gracilis, Leopmis cyanellus and Rhinichthys cataractae, but among these species mature worms were taken only from H. gracilis. Mature specimens of N. prolixus were collected from C. cyprinus, and there is no previous report of it from this species. Neoechinorhynchus rutili is reported for the first time from Hybognathus hankinsoni, Notropis dorsalis, Pimephales promelas and Rhinichthys cataractae; however, mature worms were recovered from only H. hankinsoni and P. promelas. Fishes from Sandhills region in N-central Nebraska were the most heavily parasitized and Neoechinorhynchus cylindratus was the most frequently encountered acanthocephalan. INTRODUCTION Although numerous parasite surveys of freshwater fishes have been made in Midwestern states, there is no published record of an acanthocephalan from Nebraska fishes except for incidental mentio'n (Bullock and Samuel, 1975) of Tanaorhamphus longirostris. The present study was undertaken to record the presence, distribution and severity of infection of acanthocephalans in Nebraska fishes. MATERIALS AND METHODS This survey was begun in April 1971 and continued through August 1974. Most extensive collecting was during the summers of 1972 and 1973. Fishes were collected from 71 sites (Fig. 1) representing reservoirs, lakes and creeks where fishing pressture is generally heaviest. SOUTHEAST: 1. Missouri River at Brownville*, 2. Roadside ditch 1 mile E Auburn, 3. Easly Creek*, 4. Burchard Lake, 5. Big Blue River at Homesville*, 6. Cub Creek 5 miles S Plymouth*, 7. Turkey Creek 3 miles SW Dorchester*, 8. Turkey Creek at Pleasant Dale*, 9. Big Blue River at Beaver Crossing*, 10. Dry Creek 2 miles SE Hebron*, 11. Republican River at Guide Rock*, 12. Elm Creek*, 13. Republican River at Red Cloud*, 14. Little Blue River*, 15. Plum Creek at Seward*, 16. Bluestem Lake, 17. Stagecoach Lake, 18. Wagon Train Lake, 19. Yankee Hill Lake, 20. Conestoga Lake, 21. Pawnee Lake, 22. Branched Oak Lake, 23. Missouri River at Nebraska ;City*, 24. Salt Creek at Ashland*, 25. Platte River at Louisville*.

Forest Succession on the Republican River Floodplain in Clay County, Kansas

ment Station. This study supported by The Kansas Agricultural Experiment Station, also fulfilled a part of the requirement of the Ph.D. degree in plant ecology. ABSTRACT. On the Republican River floodplain in Clay County, Kansas, 39 forest stands were plot sampled in 1968. Salix interior (sandbar willow), S. amyg- daloides (almondleaf willow), and Populus deltoides (cottonwood) appeared the first or second year after alluvium was exposed above water level. Salix interior rarely persisted more than 10 years, S. amygdaloides not more than 30 years, and P. deltoides about a century. Young of these species did not survive in established stands. After about 100 years dominant trees included Ulmus americana (American elm), Celtis occidentalis (common hackberry), Fraxinus pensylvanica (green ash), Morus rubra (red mulberry), and Acer negundo (boxelder). No stand had attained climax, but Celtis occidentalis and Ulmus americana would likely have been dominants. Celtis may be the sole dominant in the future now that Dutch elm disease has en- tered the area. For young (0-10) and old (>60 years stands, mean tree density was 24,000/ha (9,710/acre) and 5,000/ha (2,020/acre), mean basal area was 20 m2/ha (87 ft2/ acre) and 39 m2/ha (170 ft2/acre) and mean basal area per tree > 6 cm diameter was 58 and 638 cm2, respectively. The amount of light that penetrated the forest capony ranged from 18% in young to 2% in old stands. Competition, especially ef- fects of shading, is thought to be more important than changes in soil in eliminating pioneer woody species. Polygonum lapathifolium, Ambrosia trifida and Conyza canadensis were the most common herbs in young stands. Galium aparine had a frequency of 20% in young stands and over 70% in stands more than 30 years old. Rhus radicans and Partheno- cissus quinquifolia were absent in young but common in old stands. Studies of floodplain forest succession provide knowledge that can be applied in managing timber, wildlife, recreation, and floods. Such forests in Kansas and nearby states have been little studied. In Kansas Schaffner (1906) referred briefly to river-bottom forests in Clay County; Smith (1940) to one 200-year old stand in the Smoky Hill Valley in Geary County; and Gesink, Tomanek and Hulett (1970)