SEEDLINGS

The factors which cause the death of seedlings were examined and an attempt was made to determine the selective forces to which they are subjected in the field. After briefly dealing with the difficulties of defining a seedling, I examine a few cases from the recent literature in which the causes of seedling mortality are identified and quantified either by monitoring populations under natural conditions or by manipulating the environment experimentally. The special vulnerability of the immediate post-germination phase is illustrated and the consistent underestimation of seedling loss in many studies is suggested. Some interesting cases of the effects of neighbours on seedling mortality are examined and it is shown that nearest neighbours may affect a seedling's chance of being grazed. It is concluded that since the causes of seedling mortality-are so varied and unpredictable in most habitats, individual plasticity may provide a better strategy for survival than highly specialized adaptations to specific mortality factors.