It appeared that sugarberry and cedar elm were the climax dominants, while pecan was a member of the climax as a persistent subclimax
communities and endangered species of Texas are dependent on fire.
which are known to have been subclimax
prairie fifty years ago, are now covered with a good growth of bur oak and hickory.
From this perspective, woody and grassy savannahs only represent the climax vegetation in the most arid climates, and the mixture of grasslands and scrub in the other areas now occupied by savannahs should be considered as an anomaly, a subclimax
due to fire.
White birch is the earliest successional, most shade-intolerant species of the four species in our study; red oak and yellow birch have intermediate shade tolerance and are considered mid- to late-successional species; and red maple is fairly shade tolerant and is considered a subclimax
species (Burns and Honkala 1990).
These may become the dominant tree species in subclimax
old growth forests, and may persist on into the climax forests.
This model assumes continuous and reversible transitions along a single, monotonic gradient between an overgrazed subclimax
and an undisturbed climax state of vegetation and assumes that grazing and interannual variation in rainfall cause vegetation to change in the same way.