Land Cover Map of Iowa, 1999

Land Cover of Iowa in 1999

Iowa Biodiesel and Ethanol Processing Plants, January 2006

Maps of Iowa's Biodiesel and Ethanol Processing Plants.

Iowa Biodiesel and Ethanol Processing Plants, July 1, 2008

Iowa Grain Facilities Map

A Research Report on Roadside Vegetation Management, December 1975

According to prevailing ecological theory one would expect the most stable vegetation on sites which are least disturbed (Odum 1971). According to theory one would also expect the most diversity of species on undisturbed sites (Odum 1971). This stable and diverse community would be produced over a period of many years through a process of plant succession where annual herbs are replaced by perennial herbs and finally woody plants would come to dominate and perpetuate the community. Another ecological theory holds that the complexity (structure and species diversity) of a plant community is dependent upon the amount of disturbance to which it is subjected (Woodwell, 1970). According to this theory the normal succession of a plant community through its various stages may be arrested at some point depending upon the nature and severity of the disturbance. In applying these theories to roadside vegetation it becomes apparent that mass herbicide spraying and extensive mowing of roadsides has produced a relatively simple and unstable vegetation. It follows that if disturbances were reduced not only would the roadside plant community increase in stability but maintenance costs and energy usage would be reduced. In this study we have investigated several aspects of reduced disturbances on roadside vegetation. Research has centered on the effectiveness of spot spraying techniques on noxious weed control, establishment of native grass cover where ditch cleaning and other disturbance has left the bare soil exposed and the response of roadside vegetation when released from annual mass spraying.

Report on applying agreed-upon procedures to the Villisca Municipal Power Plant’s accounting procedures, cash and investment balances and compliance with Code of Iowa requirements for the period February 1, 2007 through December 31, 2010

Report on applying agreed-upon procedures to the Villisca Municipal Power Plant’s accounting procedures, cash and investment balances and compliance with Code of Iowa requirements for the period February 1, 2007 through December 31, 2010

Iowa Biodiesel and Ethanol Processing Plants, January 2010

Maps of Iowa's Biodiesel and Ethanol Processing Plants.

Evaluation of Cover Aggregate Stripping Characteristics, HR-182, 1979

The purpose of Research Project HR-182 was to identify those aggregate types which would perform satisfactorily as seal coat aggregates. Aggregates were chosen from across the State to represent the various types normally encountered and were used with two different types of binder bitumens. A water spray treatment was also included to simulate the effects of rainfall. The evaluation was based upon aggregate retention. Due to the influence of unexpected variables upon the field samples, the laboratory data are reliable for only the most general observations. Namely, that gravels as a group appear to be retained better than carbonates and rain-fall shortly after seal coat placement can affect aggregate retention. The subsequent field observations and analysis of skid resistance data permit the following conclusions: 1. Aggregate retention is influenced by lithologic type with the gravels, quartzite, haydite, dolomites, and medium grained limestones performing best. 2. Aggregate retention is not influenced by binder bitumen type. 3. Friction values of seal coats are influ-enced by aggregate retention and/or lithologic type. The following recommendations have been determined: The aggregate used for cover aggregate/seal coat projects should be Type 4 or better skid resistance as identified in Iowa DOT Materials Instructional Memorandum T-203. This will result in maximizing the possibility of good aggregate retention and skid resistance.

An Evaluation of Cover Aggregate Stripping Characteristics, Progress Report, HR-182, 1977

The increasing use of seal coats for surface restoration and the concurrent increase in failures of such treatments prompted the current research. Field observations indicated that certain aggregate types seemed to be more susceptible to failure, including stripping and disintegration. The research was thus designed to try to identify those aggregate types which would perform satisfactorily under normal conditions.

Do fire and seed additions alter strong seed timing and priority effects on prairie establishment?, 2011

Many prairie restoration projects are hampered by a lack of knowledge on how to restore the high diversity found in prairies, while at the same time preventing the establishment of a large weedy component. Methods are needed to increase diversity and abundance of native species while minimizing exotic species invasions in both 1) newly planted restorations and 2) established restorations. We established an experiment in Story and Monona counties in 2005 to determine the effects of different native cover crop species and timing of seeding on the establishment of new prairie restorations. We found that adding a 30-species prairie mix in early spring led to diverse native communities, but adding the mix in the late summer or the following year after cover crops established led to low diversity communities dominated by exotics. The identity of cover crops affected communities less than timing of seed additions. A second seed addition added to ash after a spring fire in the seventh year (Monona County site) increased recruitment from the prairie mix slightly, but the increase was not enough to cause convergence in the treatments. Surprisingly, the second seed addition increased diversity only in communities that were already the most diverse (i.e., in plots seeded with the prairie mix in early spring before cover crops established). These results imply that 1) cover crops are not effective for establishing prairie and 2) over seeding into established plots may not be an easy and efficient way to increase native recruitment and lower weedy species abundances. Therefore, focusing on establishing high levels of recruitment and diversity and excluding weedy species during the critical time early in establishment should be a priority for new projects.