Nicklen E Fleur, Wagner Diane
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775-7000, USA.
Oecologia. 2006 May;148(1):81-7. doi: 10.1007/s00442-006-0359-6. Epub 2006 Feb 1.
Many plant species attract ants onto their foliage with food rewards or nesting space. However, ants can interfere with plant reproduction when they visit flowers. This study tests whether Acacia constricta separates visiting ant species temporally or spatially from newly opened inflorescences and pollinators. The diurnal activity patterns of ants and A. constricta pollinators peaked at different times of day, and the activity of pollinators followed the daily dehiscence of A. constricta inflorescences. In addition to being largely temporally separated, ants rarely visited open inflorescences. A floral ant repellent contributes to the spatial separation of ants and inflorescences. In a field experiment, ants of four species were given equal access to inflorescences in different developmental stages. On average, the frequency with which ants made initial, antennal contact with the floral stages did not differ, but ants significantly avoided secondary contact with newly opened inflorescences relative to buds and old inflorescences, and old inflorescences relative to buds. Ants also avoided contact with pollen alone, indicating that pollen is at least one source of the repellent. The results suggest A. constricta has effectively resolved the potential conflict between visiting ants and plant reproduction.
许多植物物种通过提供食物奖励或筑巢空间来吸引蚂蚁到其叶片上。然而，蚂蚁在拜访花朵时会干扰植物繁殖。本研究测试了多刺金合欢是否在时间或空间上，将拜访的蚂蚁物种与新开放的花序及传粉者隔离开来。蚂蚁和多刺金合欢传粉者的日间活动模式在一天中的不同时间达到峰值，传粉者的活动与多刺金合欢花序的每日开裂情况一致。除了在很大程度上在时间上被分隔开，蚂蚁很少拜访开放的花序。一种花部驱蚁剂有助于蚂蚁和花序在空间上的分隔。在一项田间实验中，给予四种蚂蚁同等机会接触不同发育阶段的花序。平均而言，蚂蚁最初通过触角接触各花部阶段的频率没有差异，但相对于花蕾和老花序，蚂蚁显著避免再次接触新开放的花序，相对于花蕾，蚂蚁也会避免接触老花序。蚂蚁还会避免单独接触花粉，这表明花粉至少是驱蚁剂的一个来源。结果表明，多刺金合欢有效地解决了拜访的蚂蚁与植物繁殖之间的潜在冲突。
