Proceedings of the Iowa Academy of Science Volume 93 Number Article 9 1986 Preserving Natural Diversity in Iowa's Loess Hills: Challenges and Opportunities Dean M. Roosa Donald R. Farrar Iowa State University Mark Ackelson Iowa Natural Heritage Foundation Let us know how access to this document benefits ouy Copyright ©1986 Iowa Academy of Science, Inc. Follow this and additional works at: https://scholarworks.uni.edu/pias Recommended Citation Roosa, Dean M.; Farrar, Donald R.; and Ackelson, Mark (1986) "Preserving Natural Diversity in Iowa's Loess Hills: Challenges and Opportunities," Proceedings of the Iowa Academy of Science, 93(3), 163-165. Available at: https://scholarworks.uni.edu/pias/vol93/iss3/9 This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Proceedings of the Iowa Academy of Science by an authorized editor of UNI ScholarWorks. For more information, please contact [email protected]. Roosa et al.: Preserving Natural Diversity in Iowa's Loess Hills: Challenges an Proc. Iowa Acad. Sci. 93(3): 163-165, 1986 Preserving Natural Diversity in Iowa's Loess Hills: Challenges and Opportunities DEAN M. ROOSA1, DONALD R. FARRAR2, and MARK ACKELSON3 The Loess Hills of western Iowa, due to their extent and depth, are of national importance for geological reasons. They also harbor a large portion of Iowa's remaining biological diversity, the significance of which has been underscored by studies sponsored by the State Preserves Advisory Board during the past several years. A complex of rare species of plants and animals exist in the rugged terrain; many are Great Plains species which find their only Iowa stations in these Loess Hills. Management problems, such as rapid invasion of prairies by woody species, are manifest in this landform and must be addressed in the near future. Land protection measures are being addressed by the Department of National Resources, State Preserves Advisory Board, Iowa Natural Heritage Foundation, the Iowa Chapter of The Nature Conservancy and County Conservation Boards. The National Park Service has recently designated over 10,000 acres as a National Natural Landmark. INDEX DESCRIPTORS: Loess Hills, Iowa's natural diversity, loess prairie, rare Iowa species. The geological significance of Iowa's Loess Hills has been realized Savannas since the turn of the century (e.g. Bain, 1896, 1898; Owen, 1905; A few savannas remain intact in portions of the Loess Hills, Shimek, 1896, 1907), and the biological significance has been known particularly in the southern portion, representing the original transi­ for nearly as long (e.g. Pammel, 1901; Shimek, 1908, 1910, 1911). tion between the forested southern part and the open grasslands of the Because of a long hiatus in scientific studies in the Loess Hills, the northern portion. These are becoming invaded by woody shrubs and State Preserves Advisory Board, in 1980, funded a series of studies their integrity is rapidly being compromised. designed to underscore the Hills' significance and to provide a basis Rare species for preservation. Results of these studies culminated in a symposium A large number of species uncommon to Iowa have been docu­ on the Loess Hills presented at the 96th annual meeting of the. Iowa mented as occurring in the Loess Hills (see this issue and the Academy of Science on April 17, 1984. Ten of the resulting papers, December, 1985 issue of the PROCEEDINGS). Many of these are surveying the biological diversity of the Loess Hills, were published in Great Plains species with an extension of their distribution reaching the December, 1985 issue of the PROCEEDINGS. The current issue Iowa only in the Loess Hills (see for example, Novacek, 1985). A is devoted to the Geology, Paleontolgy, and cultural history of the partial list of rare Loess Hills species follows: Hills. Given the world-wide significance of the loess deposits of western Mammals Iowa, it is surprising that there has never been a concerted effort of Grasshopper mouse ( Onychomys leucogaster) land protection in this landform region. Only in recent years has Plains pocket mouse ( Perognathus flavescens) progress been made in recognizing the Hills' importance through Southern bog lemming (Synaptomys cooperi) protection efforts. Cotton rat (Sigmadon hispidus) Reptiles and amphibians DISCUSSION Great Plains skink ( Eumeces obsoletus) Western spadefoot (Scaphiopus bombifrons) Diversiry in the Loess Hills Great Plains toad ( Bufo cognatus) Prairie Ornate box turtle (Terrepena ornata) In the Loess Hills exists the majority of Iowa's remaining prairie, Prairie rattlesnake ( Crota/is viridis) with elements of the tall-grass and mixed-grass phases dominating much of the rugged landscape. The amount of prairie remaining has Butterflies (Hesperia ottoe) not been precisely determined. Ottoe skipper Woodlands Birds As shown by original surveyor's notes, woodlands existed at the Chuck-will's-widow ( Caprimulgus carolinensis) time of settlement in the southern extreme of Iowa's Loess Hills and Plants along stream courses and sheltered slopes. Since then, forest cover has Prairie moonwort (Botrychium campestre) been increasing, providing an unusual opportunity to observe rates of Tumble grass (Schedonnardus paniculatus) migration of woody species as well as of herbaceous understory plants Sand lily ( Mentzelia decapetela) (Novacek et al. 1985). Bur Oaks (Quercus macrocarpa) dominate the Scarlet globe mallow (Sphaeralcea coccinea) forest community, with succession trending toward Basswood (Tilia Sensitive briar (Schrankia nuitallii) americana) on mesic slopes. Black Maple (Acer nigrum) occurs in Holt Missouri vetch ( Astragalus missouriensis) County, Missouri (Goodnight, 1964), providing an opportunity to Biscuit root ( Lomatium foeniculaceum) observe whether and at what rate this species will migrate northward Cobaea penstemon (Penstemrm cobaea) into Iowa. Montaine sedge ( Carex saximontana) There is a need to locate and protect the best populations of rare Loess Hills species. Such protection could come from a variety of 1State Ecologist, Wallace State Office Building, Des Moines, IA 50319 strategies including registry through The Nature Conservancy and 2Professor, Botany Department, Iowa State University, Ames, IA 50011. Trustee, Iowa acquisition by or easement with governmental agencies or private, Chapter, The Nature Conservancy, 424 10th St., Des Moines, IA 50309 non-profit organizations such as The Iowa Natural Heritage Founda­ 3Associate Director, Iowa Natural Heritage Foundation, 505 Fifth Avenue, Suite 830, tion and The Nature Conservancy. The highest degree of protection is Des Moines, IA 50309 preserve dedication through the State Preserves Advisory Board. Published by UNI ScholarWorks, 1986 1 Proceedings of the Iowa Academy of Science, Vol. 93 [1986], No. 3, Art. 9 164 PROC. IOWA ACAD. SCI. 93(1986) Documentation of known sites of native Loess Hills biota and 1985) about 5500 acres (2226 ha) are owned by the State of Iowa and discovery of new sites is occurring through natural history surveys, under the jur"sdiction of the Department of Natural Resources, about and activities of the Iowa Natural Areas Inventory and the various 2100 acres (850 ha) are owned by the County Conservation Boards of County Conservation Boards. the seven western counties, about 150 acres (61 ha) are owned by The Nature Conservancy, and about 700 acres (284 ha) are owned by the Management considerations municipalities of Council Bluffs and Sioux City (Fig. 1). A multi-faceted approach is needed for protection of sensitive Loess Hills species. Certain species require large, unbroken tracts for long­ National Natural Landmark term existence (Howe et al., 1985; Sampson, 1983). Through efforts Periodically the National Park Service has shown interest in of the Department of Natural Resources and the Iowa Chapter of The designating part of the Loess Hills as a National Natural Landmark in Nature Conservancy, some large tracts have been acquired. The State recognition of their national significance. Following recommenda­ oflowa owns a 2724 acre ( 1102 ha) tract (Loess Hills Wildlife Area) in tions of an evaluation report (Szymkowicz and Ruhe, 1981), the Monona County, a tract of 1209 acres (489 ha) in the southern portion National Park Service recently designated 10,420 acres (4217 ha) as a (Waubonsie State Park) and 865 acres (350 ha) (Stone State Park) in National Landmark (see Federal Register for May 3, 1984 for notice). the northern part. The Nature Conservancy, in cooperation with the The area exists in two tracts, one north of Turin in Monona County; State of Iowa and the Plymouth County Conservation Board, recently the other near Little Sioux in Harrison County. While this confers no purchased a 792 acre (321 ha) tract (repurchased by the Plymouth legal protection, it will make clear the fact that the Loess Hills are a CCB in June, 1986) in the extreme northern portion (Five Ridge nationally prominent feature. Formal dedication as a National Natu­ Prairie, Plymouth County). Advantages of large-tract ownership are ral Landmark occurred on August 11, 1986. (a) relative ease with which certain management methods can be applied (e.g. controlled prairie burns for community management) Loess Hills Pioneer State Forest (b) efficacy of re-introduction attempts for extirpated species (e.g. The Department of Natural Resources has recently approved a plan Prairie Chickens) (c) ease of law enforcement, and (d) ease of