Stephan J G, Wirth R, Leal I R, Meyer S T
Dept for Plant Ecology & Systematics, Univ of Kaiserslautern, 67653, Kaiserslautern, Germany,
Neotrop Entomol. 2015 Apr;44(2):123-8. doi: 10.1007/s13744-014-0267-0. Epub 2015 Jan 27.
Leaf-cutting ants of the genus Atta construct the probably largest nests among ants and are ecosystem engineers because they alter light and nutrient availability at nest sites. Besides creating canopy gaps in the forest, workers remove all vegetation from atop their nest mounds. Here, we examined the extent and spatial distribution of this nest-clearing behavior by transplanting Licania tomentosa seedlings on Atta cephalotes (Linnaeus) nest mounds in the Atlantic forest in northeast Brazil and documented defoliation patterns by the workers. Within 9 days, workers removed around 53% of the total leaf area planted per colony. All colonies showed a synchronized start of defoliation after a rain event in the fifth night after the seedlings had been transplanted. Defoliation increased with time elapsed since transplanting and with the number of entrances surrounding each seedling. In addition, workers started defoliation on the top of the mound. In contrast, the distance to the next entrance and the size of the seedling did not affect the defoliation pattern. Defoliation was not part of the colony foraging activities but was identified as an element of nest maintenance. Possible cues triggering nest-clearing behavior and the potential link between nest-clearing activities and the control of microclimate of ant nests are discussed.
切叶蚁属的切叶蚁建造了可能是蚂蚁中最大的巢穴，并且是生态系统工程师，因为它们改变了巢穴地点的光照和养分可利用性。除了在森林中制造林冠空隙外，工蚁还会清除蚁丘顶部的所有植被。在这里，我们通过将绒毛李卡尼亚幼苗移植到巴西东北部大西洋森林中切叶蚁（Atta cephalotes，林奈）的蚁丘上，研究了这种巢穴清理行为的程度和空间分布，并记录了工蚁的落叶模式。在9天内，工蚁清除了每个蚁群种植的总叶面积的约53%。在幼苗移植后的第五个晚上降雨后，所有蚁群都同步开始落叶。落叶随着移植后时间的推移以及围绕每株幼苗的入口数量的增加而增加。此外，工蚁从蚁丘顶部开始落叶。相比之下，到下一个入口的距离和幼苗的大小并没有影响落叶模式。落叶不是蚁群觅食活动的一部分，而是被确定为巢穴维护的一个要素。本文讨论了触发巢穴清理行为的可能线索以及巢穴清理活动与蚁巢小气候控制之间的潜在联系。
