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Retrospective Theses and Dissertations

Environmental Sciences

Iowa

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A Natural Area Inventory Of Ames, Iowa , William Russell Norris Jan 1995

A Natural Area Inventory Of Ames, Iowa , William Russell Norris

Retrospective Theses and Dissertations

Perhaps no state in the Union has suffered such widespread degradation of its natural vegetation as Iowa. Tallgrass prairie (including wet prairie communities, often considered to be wetlands) once covered at least 85% of this state's land area, but more than 99.9% of Iowa's original grasslands have fallen victim to the plow (Smith 1990). Wetlands once covered 11.1% of Iowa's landscape (Dahl 1990), but virtually all of these have been drained to make way for rowcrops (wetlands now cover only 1.2% of Iowa's landscape). Roughly 12 to 20% of the state was covered ...


The Influence Of Wetland Age On Bird And Aquatic Macroinvertebrate Use Of Restored Iowa Wetlands , Kristin Leigh Vanrees-Siewert Jan 1993

The Influence Of Wetland Age On Bird And Aquatic Macroinvertebrate Use Of Restored Iowa Wetlands , Kristin Leigh Vanrees-Siewert

Retrospective Theses and Dissertations

Restoration of damaged, lost, and fragmented natural ecosystems is a goal of many public and private conservation organizations, and has become an increasing part of natural resource management. Restoration of wetland habitats has received considerable interest due in part to the dramatic loss of wetland habitat (Dahl 1990), regional decline of waterfowl populations, financial incentives for private landowners to restore former wetland basins (Wetlands Reserve Programs, conservation Reserve Program), and heightened public awareness of wetland functions and values. More than 10,000 drained basins in the Prairie Pothole region of the united states have been restored to wetland conditions since ...


A Comparison Of The Bird And Aquatic Macroinvertebrate Communities Between Restored And 'Natural' Iowa Prairie Wetlands , Philip J. Delphey Jan 1991

A Comparison Of The Bird And Aquatic Macroinvertebrate Communities Between Restored And 'Natural' Iowa Prairie Wetlands , Philip J. Delphey

Retrospective Theses and Dissertations

The glaciated prairie region of north-central and northwestern Iowa once contained a 3-million-ha prairie-marsh complex, but since settlement, 95% of the area's wetlands has been lost (Bishop 1981). Wetland loss has also been great elsewhere in the Prairie Pothole Region, contributing to regional declines of breeding populations of ducks (Batt et al. 1989) and other water bird species (U.S. Fish Wildl. Serv. 1987). To recover some of this lost habitat, federal and state agencies, and private organizations have been restoring large numbers of drained basins since the middle 1980's, mostly on private agricultural land (e.g., Madsen ...


Species Richness And Nest Productivity Of Marsh Birds On Restored Prairie Potholes In Northern Iowa , Lisa Marie Hemesath Jan 1991

Species Richness And Nest Productivity Of Marsh Birds On Restored Prairie Potholes In Northern Iowa , Lisa Marie Hemesath

Retrospective Theses and Dissertations

Since the mid 1800s the number of wetlands in Iowa has decreased by 95% (Bishop 1981). Wetland drainage and the conversion of native grasslands into croplands have been primary causes of this loss. Because of this habitat loss, several wetland species have been extirpated from the state, and others have small populations (Weller 1979, Dinsmore 1981). The 1985 Farm Bill and the North American Waterfowl Management Plan provided the stimulus for wetland restoration on many of these drained basins. My objectives were to 1) determine if certain wetland characteristics affected bird colonization on restored wetlands and 2) assess the habitat ...


The Dynamics Of Nongame Bird Breeding Ecology In Iowa Alfalfa Fields , Brian James Frawley Jan 1989

The Dynamics Of Nongame Bird Breeding Ecology In Iowa Alfalfa Fields , Brian James Frawley

Retrospective Theses and Dissertations

The bird community of alfalfa (Medicago sativa) hayfields are similar to those found on prairies (grasslands). In Iowa, less than 0.02% of presettlement prairie remains (Smith 1981). Thus of necessity, grassland birds have had to nest in hayfields and other similar habitats to survive (Dinsmore 1981). Birds nesting in crop fields, especially alfalfa hayfields, must cope with a drastically changed environment. Fields are managed to achieve the best possible forage for livestock. Consequently, the needs of nesting birds are usually ignored. Alfalfa production will probably continue to be an integral part of forage production, especially for dairy farmers. In ...


Prairie Flora On The Missouri River Bluffs Of Western Iowa , John Barstow Morrill Jr. Jan 1953

Prairie Flora On The Missouri River Bluffs Of Western Iowa , John Barstow Morrill Jr.

Retrospective Theses and Dissertations

In western Iowa, from Sioux City south to Hamburg, the Missouri River flood plain is bordered by a series of abrupt loess bluffs. Because of the wide variability in exposure, because of the characteristic wind-deposited loess and because of the accessability to river migration routes, the bluffs possess a diverse, albeit characteristic flora. Investigations of localized or specialized ecological niches frequently yield not only floristic data but insight into historical development and migration movements of both individual species and floristic units. For instance, McLaughlin (1932) in his study of the sand barren flora of northwest Wisconsin was able to show ...