Differences between seed bank composition and field recruitment in a temperate zone deciduous forest

Although much is known about variation in both seed bank composition and di sturbance effects in temperate deciduous forests, understanding of how thes e components interact to determine the importance of seed banks to regenera tion is limited. To examine the interactive influences of seed bank composi tion and postdisturbance environment on seed bank recruitment, a seed bank transplant experiment was conducted in a disturbed temperate zone deciduous forest in eastern Pennsylvania. On average, 75% of the seed bank remained ungerminated. This was mainly the result of failed germination by alien spe cies. The postdisturbance environment differed in its influence or the two dominant species, Rubus allegheniensis and Phytolacca americana. Whereas R. allegheniensis recruitment did not differ between postdisturbance environm ents, significantly more P. americana seedlings emerged under more open con ditions. Different proportions of P. americana seeds germinated from the tw o seed bank sources. These results show that a large portion of the seed ba nk remains ungerminated under natural disturbances, and the age and history of the component seeds may influence the regenerative function of seed ban ks in natural ecosystems.