关键词: 杉木幼苗, 铝胁迫, 水培模拟, 外源营养调控因子, 阈值

Abstract: The secondary dispersal of small seeds in tropical forest mediated by ants often determines the final arrival site of the seeds and their fate. With Ficus benjamina, a bird-dispersed nonmyrmecochorous fig species, as test object, this paper investigated how ants respond to its seeds with different treatments (seeds from fruit with pericarp, seeds from fruit with pericarp removed, seeds from bird’s feces with pericarp, and seeds from bird’s feces with pericarp removed). Four ant species, i.e., Pheidole rhombinoda, Monomorium pharaonis, Odontoponera transversa and Paratrechina bourbonica, were recorded in the seed dispersal. The visiting frequency of the four ants was 71.7%, 23.3%, 2.5% and 2.5%, respectively, and the mean dispersal distance was 179 cm±13 cm (n=159). The major dispersal ant Ph. rhombinoda discarded 58.6% of the carried seeds in the refuse piles after consuming the pericarp. The seeds collected from ant’s refuse piles had a significantly enhanced seed germination rate (from 49.3% to 93.3%). Seed removal rate decreased significantly after the pericarp was removed (from 75.0% to 29.5%). Seed pericarp enhanced the attraction to ants, and the seeds treated by ants gained significant higher germination rate. Therefore, a significant mutualism relationship existed between F. benjamina and its dispersal ants.

Key words: Cunninghamia laceolata seedling, Al stress, Solution culture, Exogenous nutrient elements, Thresholds