Kelly Carol A
Department of Botany and Program in Ecology and Evolutionary Biology, University of Iowa, 52242, Iowa City, IA, USA.
Oecologia. 1986 Jul;69(4):600-605. doi: 10.1007/BF00410369.
Extrafloral nectaries of Cassia fasciculata attract nectar feeding ants which protect the plant against leaf herbivores. High ant visitation in late July coincided with high herbivore densities at two sites in east central Iowa. The highest level of leaf herbivory occurred during the time of flowering and early fruit filling, just after the peak of herbivore and ant activity. Results of ant exclusion experiments at the two sites showed that ant visitation resulted in decreased herbivore numbers, decreased leaf area loss, increased growth, and at one site decreased plant mortality. However, this reduction in leaf area loss and increase in growth did not translate into seed set differences between plants with and without ants at either site. Initial plant size was more important than the presence or absence of ants in determining fecundity for this temperate annual during a year of summer drought.
束花决明的花外蜜腺会吸引取食花蜜的蚂蚁，这些蚂蚁能保护植株免受食叶动物侵害。7月下旬蚂蚁频繁光顾，此时爱荷华州中东部两个地点的食草动物密度也很高。最高水平的叶片食草作用发生在开花期和果实早期充实阶段，就在食草动物和蚂蚁活动高峰之后。在这两个地点进行的蚂蚁排除实验结果表明，蚂蚁的光顾使食草动物数量减少、叶片面积损失减少、生长增加，在一个地点还降低了植株死亡率。然而，在这两个地点，叶片面积损失的减少和生长的增加并没有转化为有蚂蚁和无蚂蚁植株之间结实率的差异。在夏季干旱的一年里，对于这种温带一年生植物而言，初始植株大小在决定繁殖力方面比有无蚂蚁更为重要。
