Influence of Seed Characteristics and Site Conditions on Establishment of the Threatened Prairie Milkweed Asclepias meadii

Abstract

Abstract Population restoration and reintroduction are critical aspects of many plant conservation efforts. However, factors affecting the earliest life stages, critical to the establishment of new individuals, are often poorly understood. I investigated the influence of seed characteristics and manipulations of the field environment on seedling emergence and growth in Asclepias meadii (Mead's milkweed), a federally threatened tallgrass prairie species. Seeds of known mass and maternal plant were reared in a greenhouse and also in experimental restoration plots with combinations of pre- planting soil disturbance and spring burning treatments. In both the greenhouse and field, seed mass was positively correlated with emergence but not growth. Maternal relationships with emergence and growth were observed in the greenhouse but were generally undetectable in the field. Lower emergence was associated with field plot soil disturbance and burning, although there was no statistically significant effect of either...