Ecology of the Riffle Insects of the Firehole River, Wyoming

Abstract

I NTRODUCTION Most of the early work in stream biology was concerned with qualitative studies. Some studies have emphasized adaptations of stream organisms to their environment (Pearse 1939, Muttkowski 1939); others have considered community structure (Allee and Schmidt 1951) or stream zonation (Macan and Worthington 1951). Several biologists made faunal and zoogeographic studies (Behning 1929, Berg 1948, Thienemann 1950). Most quantitative studies were made considering the bottom fauna as fish food and have mainly been surveys to attempt to evaluate the pounds per acre of fish food available. While working as a ranger naturalist in Yellowstone National Park, I became curious as to the effect waters from hot springs would have on the fauna of the Firehole River. My interest in quantitative ecology was stimulated because the Firehole River appeared to offer the opportunity of studying rapidly changing environmental conditions and their effect on the qualitative and quantitative composition of fauna. This research was made possible by a National Science Foundation fellowship which enabled the author to spend several months in the field in early spring and late fall. A grant from the Gans Fund, Bethany College, W. Va., helped defray some of the expenses involved in the field operations. The author owes a great debt to the National Park Service and to the personnel of Yellowstone National Park for their cooperation in establishing this study and for providing facilities during the late fall and early spring. Special thanks are due to Park Naturalist David de L. Condon for his efforts in making the study possible and for his continued cooperation and aid whenever needed. Dr. Gerard A. Rohlich and Dr. Gerald W. Lawton of the College of Engineering of the University of Wisconsin performed a valuable service in analyzing water from the Firehole River. Dr. Robert W. Pennak, University of Colorado, gave advice and help in making some of the identifications. I wish to thank Dr. Arthur D. Hasler, under whose direction this work was done, for his critical evaluation of the work in progress and for the generous use of his time. This paper is based on parts of a thesis submitted in partial fulfillment of the requirements of the Ph.D. degree at the University of Wisconsin.