SHORT-TERM RESPONSE OF OLD-FIELD PLANT-COMMUNITIES TO FIRE AND DISTURBANCE

We examined the mechanisms that cause short-term changes in old-field plant communities in the lst yr following two different disturbances: tilling and burning. In particular, we wanted to determine whether sho rt-term changes in plant community structure following disturbance wer e more strongly influenced by interspecific differences in growth rate s or interspecific differences in germination and establishment abilit y. Because the density of annual plants varied more across treatments than plant size, we concluded that differences in germination and esta blishment were important causes of community change in the lst yr foll owing disturbance. Thus, a more detailed mechanistic understanding of the factors influencing germination and establishment will be necessar y to understand community patterns in this old-field system.