Humans were, in his view, alien and invasive barriers to the natural movement, or succession, of vegetation toward its destined end point: the monoclimax.
On Western rangelands, the monoclimax was presumably the vegetative cover that preceded the arrival of homesteaders: tall- and short-grass prairies on the high plains; old-growth forests in the high Rockies; and pristine desert grasslands and shrublands in the intermountain basins.
While it is noted that "presently, theory tends more towards the ideas of Gleason," the presentation of succession is nonetheless built upon on Clements' ideas of progressive development to a monoclimax
. The difference between Clements and Gleason is presented as an argument between deterministic and random, rather than between superorganism and individualistic.