Bogan, M.A., C.D. Allen, E.H. Muldavin, S.P. Platania, J.N. Stuart, G.H. Farley, P. Mehlhop, and J. Belnap. 1998. Regional trends of biological resources - southwest. pp. 543-592 in: M.J. Mac, P.A. Opler, C.E. Puckett Haecker, and P.D. Doran. Status and