Thesis (PH. D.)--University of Chicago, 1917. / "Private edition, distributed by the University of Chicago Libraries, Chicago, Illinois." "Reprinted from the Botanical gazette, vol. LXV, no. 6; June 1918." "Contributions from the Hull botanical laboratory 238." "Literature cited": p. 524-525.

This study makes use of simple statistical models which may be manipulated for projection of changes in the Kaiparowits Region of Southern Utah. A method of determining habitat preferences of small rodents from capture-recapture trapping data is proposed. It is suggested that some aspects of animal behavior regarding trapping may also be explained. Timing of flowering of Oryzopsis hymenoides and Hilaria jamesii as related to enviromental conditions was investigated, and models of the requisite conditions proposed. It is suggested that similar models may be used to describe the timing of other phenological events. Succession on disturbed sites is considered to determine predictablility of revegetation. It was determined that early stages of succession of three habitat-types are proceeding in a manner similar to that described on other areas of the pinyon-juniper forest.