Root Distribution and Respiration in a Carolina Old Field

Distributions and activities of roots of old field broomsedge were studied from June-August 1970. Roots of old field vegetation were found concentrated in the upper 10 cm of soil and uniformly distributed therein. Short-term (24 hr) respiration of roots was determined in the laboratory. The contribution of roots to total CO2 output was considered independent of proximity of above-ground vegetation. Changes in soil moisture and possibly temperature were more effective variables controlling soil respiration than were seasonal fluctuations of root biomass.