Effects of prescribed fire on the reproductive ecology of northern blazing star Liatris scariosa var. novae-angliae

摘要

I studied several factors that affected rates of seedling establishment northern blazing star (Liatris scariosa var. novae-angliae) at Kennebunk, Maine. Fire stimulated blazing star fecundity in four ways: (1) There was a four-fold increase in the number of flowering plants in recently burned units (10.6%) compared to plants in units that had not been burned for 4 y (2.4%). (2) The number of seeds per flower head was greater in recently burned units. (3) Among flower heads that had been infested with predacious moth larvae, the percentage of depredated seeds (40-50%) seas lower in recently burned units than in units that had not been burned for two or more years (78-93%). (4) Under natural conditions, seedling establishment was much greater in management units that had been burned 20 mo previously than in management units that had been burned either within the past 8 mo, or units that had not been burned for more than 4 v. These results suggest that northern blazing star benefits from fire and that these four factors are temporally linked. Fire reduced levels of sced predation and increased sced production, providing a large supply of viable seeds. Fire also reduced litter, thus providing a suitable substrate for seedling establishment and development.