Rapid nutrient transfer reduces negative effects of post‐emergence seed predation in Quercus variabilis

Abstract

Seeds of some tree species are often consumed by vertebrates after germination, resulting in the loss of cotyledons that still contain nutrients, affecting early seedling formation. However, little attention has been given to strategies employed by seeds to address post-emergence predation. Seed nutrient transfer of Quercus variabilis was quantified after removing cotyledons at 11 times, with intervals of 5 or 10 days between them. Seedling performance in the field was evaluated at the end of the first- and second-growing seasons. Cotyledon removal on the 10th day had no significant impact on seedling survival. However, removal of cotyledon on the fifth day substantially reduced seedling survival rates, with effects lasting until the end of the second growing season. Seedling growth was not influenced by cotyledon removal after 20 days, but removal of cotyledon on day 15 resulted in a significant decrease in seedling height and ground diameter at the end of the second growing season. The percentage of residual nutrients in the cotyledons was always less than the residual biomass as nutrient transfer was rapid during the critical stages of seedling establishment. Nutrient transfer was asynchronous; transfer rate of starch was the highest, followed by K, P, and N. Rapid nutrient transfer and its asynchrony might be the regeneration strategy of Quercus seeds under predation pressure. Therefore, seeds of Quercus should be protected in the early stages of seedling establishment.