Science and Mathematics Education Commons^™

Weed Seedbanks And Seedling Emergence In A Two And Three Crop Narrow Strip Intercropping/Rotation System, Shawn R. Wright, Douglas D. Buhler, Keith A. Kohler, Richard M. Cruse

Journal of the Iowa Academy of Science: JIAS

Weed populations in agronomic settings are, in part, a reflection of the cropping system utilized. The goal of this project was to gain an understanding of the weed population dynamics in a narrow strip intercropping (NSI) rotation by assessing the weed seedbank, weed emergence, and seedling establishment over the growing season for a corn-soybean (two-crop), and a corn-soybean-oat+berseem clover (three-crop) system. Field research was conducted in 1994 and 1995, near Nashua, IA, and each crop was grown m 4.6 m wide strips. Giant foxtail and total weed seed densities were significantly lower in the three-crop NSI rotation system than in …

Announcements Of Upcoming Meetings And Symposia

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Introduction: A Perspective On Midwest Amphibian Declines, Gary S. Casper

Journal of the Iowa Academy of Science: JIAS

On March 21, 1998, approximately 300 scientists and students gathered at the Milwaukee Public Museum for two days of scientific presentations and intense discussion on amphibian declines and malformities. Never before had so many persons come together to address amphibian conservation in the Midwestern United States (Minnesota, Wisconsin, Michigan, Illinois, Indiana, Ohio, Iowa, and Missouri).

History Of Minnesota Frog Abnormalities: Do Recent Findings Represent A New Phenomenon?, David M. Hoppe

Journal of the Iowa Academy of Science: JIAS

Two lines of investigation were used to determine whether recent Minnesota reports of frog abnormalities differ from historical reports: (1) museum collection studies paired with follow-up field surveys, and (2) comparison of recent and earlier field surveys in west-central Minnesota. For the museum study I examined 2433 northern leopard frogs (Rana pipiens) in the Bell Museum of Natural History collections of the University of Minnesota, collected during 1958-63. 0.7% of frogs were found to have abnormalities, consisting of 0.5% predator amputations and 0.2% malformations. Three types of malformation were found: missing hindlimbs, vestigial feet, and fused digits. Conspicuously absent from …

Effects Of Pcb 126 And Ammonia, Alone And In Combination, On Green Frog (Rana Clamitans) And Leopard Frog (R. Pipiens) Hatching Success, Development, And Metamorphosis, Mariana Beatriz Jofre, Michele L. Rosenshield, William H. Karasov

Journal of the Iowa Academy of Science: JIAS

The Green Bay watershed in Wisconsin is polluted with polychlorinated biphenyls (PCBs), dioxin, heavy metals, ammonia, and over 100 organic contaminants. In this study we exposed embryos and larvae of two ranid species commonly occurring in the Green Bay ecosystem, the green frog (Rana clamitans) and the leopard frog (R. pipiens), to PCB 126 (3,3', 4,4', 5-Pentachlorobyphenil, nominal concentrations 0-50 μg/l, two control treatments: water plus 0.08% acetone as carrier for the PCB, water alone), unionized ammonia (0-2 mg/I), and mixtures of both contaminants. Exposure to PCB 126 did not cause significant mortality of embryos before hatching. However, exposure to …

Reduction In Road Mortality In A Northern Leopard Frog Population, Madeleine H. Linck

Journal of the Iowa Academy of Science: JIAS

Since spring of 1994, Hennepin Parks Natural Resources Management staff, assisted by numerous volunteers, has been working to reduce road mortality among migrating Northern Leopard Frogs (Rana pipiens) adjacent to Baker Park Reserve in Maple Plain, Hennepin County, Minnesota. A county road separates the overwintering site from breeding habitat within the park. With steadily increasing traffic over the years, this population of frogs was in serious decline. For the first two years (1994 and 1995) rescue efforts were limited to the spring collection of frogs as they migrated out of the overwintering lake coward the breeding wetlands, although the road …

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Book Review: An Illustrated Guide To Iowa Prairie Plants, Paul Weihe

Journal of the Iowa Academy of Science: JIAS

An Illustrated Guide to Iowa Prairie Plants. Paul Christiansen and Mark Müller. 1999. University of Iowa Press, Iowa City, Iowa. IX + 237 pages. ISBN 0-87745-660-7 hdbd., ISBN 0-87745- 661-5 pbk.

Iowans are increasingly aware of the significance of the tallgrass prairie, and efforts to preserve and protect this once-widespread ecosystem are ongoing. An obvious focus of these efforts 1s to conserve the native flora. When Bison and Elk disappeared from the landscape and row-crop agriculture appeared, a few of the native plants remained in old cemeteries, along roadsides, and in a few prairie remnants. Workers are now attempting to …

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Corn (Zea Mays L.) Yield Response To Nitrogen Fertilizer In Conventional And Alternative Rotations, M. M. Harbur, M. Ghaffarzadeh, R. M. Cruse

Journal of the Iowa Academy of Science: JIAS

Nitrogen (N) fertilization recommendations are not available for corn in rotation with small grains or forages despite the possibility that the N response may differ from that of more conventional corn-soybean rotations. Rotations of corn with soybean (CS), corn with soybean and oat (CSO) and corn with soybean and an oat/berseem clover intercrop (CSOB) were established in 1991 and studied from 1993 through 1998 to determine the optimal N fertilization level for corn produced in each rotation. Corn in each rotation received NH4N03 applied at the rates of 0, 56, 112, or 168 kg N ha^-1. Significant differences …

Photo-Enhanced Toxicity In Amphibians: Synergistic Interactions Of Solar Ultraviolet Radiation And Aquatic Contaminants, Edward E. Little, Robin Calfee, Richard Skinker, Angela Zaga-Parkhurst, Mace G. Barron

Journal of the Iowa Academy of Science: JIAS

Amphibians experience a broad range of multiple environmental stressors that occur in natural systems. However, the impact of combinations of these stressors on amphibians are rarely examined. The effect of two stressors on amphibians, solar ultraviolet radiation (SUV) and environmental contamination, was investigated. To examine the interactive effects of SUV and environmental contaminants, Hyla venicolor and Rana sphenocephala were exposed in the laboratory to a carbamate insecticide and the water soluble fraction of a weathered petroleum in combination with various intensities of simulated solar radiation (SSR). The contaminants were tested at environmentally relevant concentrations. Synergistic interactions between SSR and these …

Effects Of Altosid And Abate-4e On Deformities And Survival In Southern Leopard Frogs Under Semi-Natural Conditions, Donald W. Sparling

Journal of the Iowa Academy of Science: JIAS

Since 1995 when a group of school children in Minnesota found frogs with supernumerary limbs and missing limbs, there has been widespread interest in the amphibian malformation issue. Despite considerable effort to understand this problem, its extent and seriousness as well as direct causes of these malformations remain unclear. Progress on this issue has been hampered by a scarcity of scientifically reliable information on historical rates of abnormalities under undisturbed conditions and by the normal turnaround times of data collection, sample analysis and publication. One of the very few peer-reviewed publications with field-collected data showed that an average of 12% …

Field Investigations Of Malformed Frogs In Minnesota 1993-97, Judy C. Helgen, Mark C. Gernes, Susan M. Kersten, Joel W. Chirhart, Jeff T. Canfield, Dorothy Bowers, Jon Haferman, Robert G. Mckinnell, David M. Hoppe

Journal of the Iowa Academy of Science: JIAS

Reports of malformed frogs were made to the Minnesota Pollution Control Agency (MPCA) from different parts of Minnesota in 1993, 1995, 1996, and 1997 and one, nine, 190, and 172 reports were received, respectively. MPCA field crews and Drs. Hoppe and McKinnell documented malformed frog locations starting in 1993. By 1997, MPCA field crews documented malformed frogs at 62 locations in Minnesota, in 29 of 87 counties. Most malformations were in young metamorphs of Rana pipiens but they were observed also in R. clamitans, R. septentrionalis, R. sylvatica, Bufo americanus, and Hyla spp. Frequencies of malformations varied by time of …

Revitalization Of Ephemeral Pools As Frog Breeding Habitat In An Illinois Forest Preserve, Denins Nyberg, Irene Lerner

Journal of the Iowa Academy of Science: JIAS

Almost all land in the eastern United States that has been acquired to preserve nature was once in agricultural usage, and because of this, alterations of ephemeral pool hydrology are common in forest preserves and parks. These ephemeral pools are an important breeding resource for many amphibian species. We hypothesized that filling drainage ditches and recreating a more natural topography at eroded berms would enhance amphibian populations in the forest preserve. Restoration of the hydrology was begun by volunteers in 1993 and was associated with management to reduce non-native woody vegetation. Three ephemeral pools have had maximum water levels raised …

Amphibian And Reptile Surveys In The Kaskaskia River Drainage Of Illinois During 1997 And 1998, Allan K. Wilson

Journal of the Iowa Academy of Science: JIAS

Currently there is little doubt among the scientific community of the decline of amphibians on an international scale (Berger et al. 1998, Kuzmin 1994, Laurance et al. 1996, Lips 1998) and across North America (Delis et al. 1996, Drost and Fellers 1996, Lannoo 1994). In light of these widespread declines it is essential that current populations be inventoried and evaluated so that future population changes can be detected and hopefully correlated with possible causes. Critical baseline information is lost when monitoring is not implemented until after a problem is detected. The effectiveness of long-term studies in detecting amphibian declines (Beebee …

Index For Volume 107

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Statement Of The Position Of The Iowa Academy Of Science On The Validity Of Evolutionary Science And On The Status Of Creationism As A Scientific Explanation Of Natural Phenomena

Journal of the Iowa Academy of Science: JIAS

Current attempts to introduce "scientific creationism", "creationism", or the Judeo-Christian biblical account of creation, as well as to reframe the discussion around terms such as "abrupt appearance theory", "intelligent design theory", or other disguised forms of creationism into the science classroom along with or instead of evolutionary science are strongly opposed by The Iowa Academy of Science on the grounds that creationism, in whatever form, is a religious doctrine and not science.

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Cover - Investigating Amphibian Declines: Proceedings Of The 1998 Declining Amphibians Conference

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Interactive Effects Of Anthropogenic, Environmental, And Biotic Stressors On Multiple Endpoints In Hyla Chrysoscelis, Carol A. Britson, Stephen T. Threlkeld

Journal of the Iowa Academy of Science: JIAS

Multiple stressors have been proposed as causative agents for declining populations and increased incidence of malformations in amphibians although few studies have examined possible interactions among these stressors. We measured interactive effects of UV radiation, three chemicals, and interspecific competition (with Rana 1phenocephala) on multiple endpoints in Hyla chrysoscelis using a center point- and chemical-free control-enhanced 2⁴ factorial design. UV radiation was transmitted or filtered using OP-4 or OP-3 acrylite filters installed above 72, 500-liter mesocosms on 16 May 1997. Methyl mercury, chlorpyrifos, and atrazine were applied at levels of 0, 10, 50, and 100 % of 400 ppb, …

Defining Anuran Malformations In The Context Of A Developmental Problem, Carol U. Meteyer, Rebecca A. Cole, Kathryn A. Converse, Douglas E. Docherty, Mark Wolcott, Judy C. Helgen, Richard Levey, Laura Eaton-Poole, James G. Burkhart

Journal of the Iowa Academy of Science: JIAS

This paper summarizes terminology and general concepts involved in animal development for the purpose of providing background for the study and understanding of frog malformations. The results of our radiographic investigation of rear limb malformations in Rana pipiens provide evidence that frog malformations are the product of early developmental errors. Although bacteria, parasites and viruses were identified in these metamorphosed frogs, the relevant window to look for the teratogenic affect of these agents is in the early tadpole stage during limb development. As a result, our microbiological findings must be regarded as inconclusive relative to determining their contribution to malformations …

A Relationship Between Trematode Metacercariae And Bullfrog Limb Abnormalities, James L. Christiansen, Heather Feltman

Journal of the Iowa Academy of Science: JIAS

This study is the first report of statistically significant relationships between limb abnormalities and trematode metacercariae in natural populations of frogs. We examined only parasite associations and did not investigate numerous potential pollutants that have been suggested by others to be associated with frog limb abnormalities. Rana catesbeiana of varying ages with a variety of limb abnormalities were found during the flood of 1993. By June 1994, the receding flood waters had left four pools, each with newly metamorphosing bullfrogs. Only one of the pools contained abnormal individuals and histological examination revealed significantly greater prevalence of trematode metacercarial infection in …

Morphological Abnormalities In Illinois Cricket Frogs, Acris Crepitans, 1968-71, Robert H. Gray

Journal of the Iowa Academy of Science: JIAS

Reports of malformed amphibians have been increasing, including external deformities such as missing or extra arms and legs, missing eyes and mandibles, and internal abnormalities involving the bladder, digestive system, and testes. Natural phenomena such as limb amputations during predation attempts by other animals, parasitism, xenobiotic chemicals (herbicides, insecticides, fertilizers and others), and UV-B or other radiation (either directly or indirectly by triggering production of toxicants from nontoxic chemicals) have all been linked to amphibian abnormalities. From 1968-71, I studied the natural history, effective breeding size, and seasonal, annual, and geographic variation in color morph frequencies of cricket frogs (Acris …

Amphibian Use Of Constructed Ponds On Maryland's Eastern Shore, Catherine E. Merovich, James H. Howard

Journal of the Iowa Academy of Science: JIAS

Amphibian assemblages were sampled at nine constructed ponds (three in each age category: new ponds-age <1 yr, young ponds-age 4-5 yr, old ponds-age >30 yr) on Maryland's eastern shore (May-October 1994, March-August 1995) using a total of 27 drift fence and funnel trap arrays. The importance of habitat and landscape variables including pond age was considered in explaining amphibian use and distribution across ponds. Specifically, amphibian (1) abundance; (2) composition; (3) diversity; (4) richness; and (5) reproductive success were studied. During both years, we captured 1904 individuals comprising ten species. The most frequently collected species (species found in all treatments) were Bufo fowleri, Rana sphenocephala utricularius, and Rana …

A Winter/Spring Study Of Salamanders In A Disturbed, Fragmented Habitat Surrounded By Farm Land, James C. Ball

Journal of the Iowa Academy of Science: JIAS

The continued development of fragmented habitats contributes to the decline of amphibians species, and there needs to be a method for evaluating the potential of these habitats to sustain amphibian populations. The effect of fragmented and disturbed habitats among salamander species is difficult to assess because these caudates are difficult to find and enumerate. One approach for estimating the total population of salamanders is to sample them when they migrate to their winter/spring breeding ponds. One fragmented habitat in Southern Michigan was sampled for breeding salamanders during the winter/spring of 1997. Four species of salamanders were detected at this site; …

Amphibians And Reptiles Captured In Drift Fences In Northwest Wisconsin Pine Barrens, James O. Evrard, Steven R. Hoffman

Journal of the Iowa Academy of Science: JIAS

Drift fence surveys were initiated by the Wisconsin Department of Natural Resources (WDNR) in the Crex Meadows Wildlife Area (CMWA) in 1993. Systematic drift fence trapping of amphibians and reptiles in the northwest pine barrens was conducted in a 1996- 97 cooperative effort by the WDNR, the U.S. Forest Service (USFS), and the Great Lakes Indian Fish and Wildlife Commission (GLIFWC). Drift fences were operated in four managed barrens properties, the CMWA, Namekagon Barrens Wildlife Area (NBWA), the Douglas County Wildlife Area (DCWA), and the Moquah Barrens Wildlife Area (MBWA). Eighteen amphibian and reptile species (four salamanders, eight anurans, one …

Frog And Toad Population Monitoring In Michigan, Lori G. Sargent

Journal of the Iowa Academy of Science: JIAS

A volunteer-based monitoring project for frog and toad populations in Michigan was initiated in 1996. The survey protocols developed by the North American Amphibian Monitoring Program (NAAMP) were used and modified to suit the needs of the Michigan project and because of the highly variable Michigan spring weather. The modifications include route establishment, recommended dates during which surveys are conducted, and a more specific definition of population indices. Development of the project included training workshops for volunteers.

Differences Among The Spatial Distribution Of Sympatric Amphibians, Robert Brodman

Journal of the Iowa Academy of Science: JIAS

To assess amphibian declines, the factors that cause natural fluctuations in population size must be considered (Pechmann et al. 1991). Interspecific competition, predation and pond drying are known to influence patterns of distribution and composition of larval amphibian assemblages (Morin 1983, Brodman 1996, Skelly 1996). While a few studies have quantified amphibian patterns across a large number of ponds, most studies on breeding pond distributions have typically focused on pond characteristics associated with pairs of coexisting species (Thompson and Gates 1982, Skelly 1996). Little has been examined about the differences among the spatial distributions of all potentially interacting amphibian populations …