6HYNES H B N. The stream and its valley[J]. Verhandlungen der Interationalen Vereinigung Fur Theoretische und Angewandte Limnologie, 1975, 19:1-15.
7VANNOTE R L, MINSHALL G W, CUMMINS K W,et al. The river continuum concept[J]. Canadian Journal of Fisheries and Aquatic Sciences, 1980,37 : 130 - 137.
8JUNK W J, BAYLEY P B, SPARKS R E. The flood pulse concept in river - floodplain systems [ M ]. Canada :Canadian Special Publication of Fisheries and Aquatic Sciences, 1989:110-127.
9BAILEY R G. Ecoregions of the United States. Map ( scale 1:7,500,030) [ M ]. Ogden, Utah : U.S. Dept. of Agriculture, Forest Service. Intermountain Region, 1976.
10OMERNIK J M. Ecoregions of the conterminous United States[J]. Annals of the Association of American Geographers, 1987, 77: 118-125.
