The Annual Seed Rain of Adventive Herbs in a Radiation Damaged Forest

The seasonal and numerical distribution of seeds of adventive species entering the central 50—m zone of the irradiated forest facility of Brookhaven National Laboratory was studied by the exposure plate method. Adventive seeds were collected from 15 August to 10 December 1963 and 7 May to 1 September 1964 and the cumulative total per hectare noted. The species found on the traps matched fairly well those species established in the study area, suggesting that successional patterns in the 50—m zone are dependent on the availability of aerially borne seeds from surrounding areas.