The seed bank in a population of an endemic plant species and its ecological significance

A large seed reserve was present at a population site of the narrowly endemic winter annual plant species Leavenworthia stylosa Gray. From the seed bank present in the soil in the spring of 1971, seedlings were produced in the autumn of each of seven subsequent years (1971-1977). The presence of a large seed bank ensures continuation (without immigration) of the population at a given site, even if seeds are not produced every year, and it increases the size, and thus the genetic diversity and stability, of the effective breeding population. The implications of natural seed banks to preservation of plant species are discussed.