Degree Name

Master of Science (MS)

Semester of Degree Completion

2003

Thesis Director

Andrew S. Methven

Abstract

Phaeophyscia leana (Tuck.) Essl., an endemic North American lichen species presently known to occur only within the Ohio River basin, is state-endangered in Illinois and a potential candidate for the Federal Endangered Species list. Since it utilizes periodically inundated corticolous substrates associated with river channels, oxbow lakes, and sloughs, this imperiled lichen is sensitive to landuse patterns within river floodplains. Surveys for P. leana were conducted to recensus previously documented populations, thereby assessing their stability, and to identify additional populations within the Ohio River Basin. Watercraft surveys were conducted on the Little Wabash River, from Carmi to New Haven, Illinois, and on the Wabash River from Darwin, Illinois, to the terminus at the Ohio River. Watercraft surveys resulted in the discovery of five new populations of P. leana, two in Illinois and three in Indiana, all of which were located south of Illinois State Route 141. Land-based surveys in Illinois identified new populations within the floodplain formed at the confluence of the Wabash and Ohio Rivers in Gallatin County and within the Black Bottom of Massac County. Nine large oxbow lake communities and backwater slough channels were found to support populations of P. leana within the Gallatin Bottoms which is the population center for P. leana in Illinois. Additions to the Illinois core site list include large populations at Fehrer Lake, Big Lake, and Saline Mines, all within the Gallatin Bottoms floodplain. Watercraft reconnaisance of the Wabash River and Ohio River floodplains (the Big Rivers Region) in Indiana led to the discovery of P. leana populations in Posey, Spencer, Perry, Crawford, and Switzerland County, Indiana, as well as a population in Trimble County, Kentucky. The population located at Vevay, Indiana, in Switzerland County is the closest documented population to the type locality near Cincinnati, Ohio. Land-based surveys conducted in the Hoosier National Forest and the Harrison-Crawford State Forest elucidated the only core site in Indiana, the Mano Point population, near Derby. A population was also discovered in Tennessee at the Hartsville boat launch on the Cumberland River (Old Hickory Lake). Core sites in Tennessee include the Hartsville population as well as populations discovered by Loy R. Phillippe on the Caney Fork River near Hell Bend (downstream from Carthage) and below the Center Hill Dam located on Wolf Island. A total of six core sites were located in this survey and eighty-five positions, where P. leana was observed growing, were recorded with UTM coordinates.

Download

Included in

Life Sciences Commons

Share

COinS