Fire and Climax
Fire and Climax
Bureaucratic Divisions of Scientific Labor
Chapter 2 explains the origins of another blind spot, fire, and its relation to Frederic Clements’ theory of succession. Clements conceived of vegetation as in equilibrium with climate and soils; following disturbance, the processes that produced a given vegetation community over long time scales (primary succession) would drive a return to “climax” equilibrium conditions (secondary succession). Clements viewed fire as an external disturbance that interfered with succession, and the Forest Service considered all fires to be unequivocally bad. There was strong pressure to graze the national forests heavily to suppress fires, but a policy of “overgrazing” was impolitic. Arthur Sampson, a former student of Clements, proposed that overgrazing could be detected early by studying plant composition for signs of departure from climax conditions: grazing was counter-successional, and stocking rates therefore could be set to balance successional forces and maintain the vegetation in a desired state. Jardine misinterpreted Sampson’s argument to mean that correct stocking rates could be static, avoiding the difficulty of adjusting herds to fluctuating rainfall and forage production. Circumstantial evidence suggests that successional theory and static stocking were adopted to ensure that there would be little or no grass to fuel fires during drought years.
Keywords: Arthur Sampson, climax, fire, forestry, grazing, overgrazing, retrogression, rotation grazing, plant succession