Floristic composition before and after prescribed fire on a jack pine clear-cut site innorthern lower Michigan

Abstract

Permanent frequency and cover plots were established and monitored for 3 years on a recent jack pine (Pinusbanksiana Lamb.) clear-cut in northern lower Michigan to characterize vegetational changes on burned and unburned blocks. Community data were also recorded from an adjacent mature jack pine stand. Vaccinium dominated (30% cover) the mature jack pine understory, whereas at the time of burning, the clear-cut site (3 year old) was dominated (33% cover) by Carexpensylvanica Lam. Two years after fire, burned blocks were significantly different from unburned blocks in terms of total cover, cover of grasses and sedges, and number of perennial forbs. Egler's initial floristic composition model was supported by the fact that every species in the mature jack pine understory was present on either the unburned or burned clearcut blocks.