Studies on refulation of herbivores by ants in tropical rain forests

为了阐明婆罗洲热带雨林林冠中蚂蚁的种类组成、丰度和空间分布，利用该系统对马来西亚沙捞越兰堡国家公园双龙果林15种树种的林冠进行了多次蚂蚁丰度调查。此外，为了分析蚂蚁对草食动物的影响，还对树木的草食动物丰度和草食对树叶的伤害进行了调查。此外，还在野外研究了森林冠层中附生植物和空气土壤的存在对蚂蚁筑巢地可用性的影响。结果表明，少数蚁种同时利用地上和树上空间作为其活动范围，蚁种在林冠的空间分布相当稳定，特定蚁种更倾向于在林冠或附生植物上筑巢。少数以地表为活动范围的蚂蚁会将活动范围暂时扩展到树干表面，而在一些附生植物的domatia中定居的蚂蚁在林冠层中经常占据优势地位。这两种蚂蚁的活动范围在空间上几乎没有重叠，可能会间接影响其他物种在林冠层中的空间分布。因此，可以推测森林冠层蚂蚁群落存在着强烈的种间竞争。这些数据表明，寄生于附生植物的蚂蚁可能会调节藤本植物和其他附生植物的丰度，并通过这种调节间接影响其他蚂蚁的空间分布。草食损害与蚂蚁丰度之间的关系表明，这些蚂蚁物种可能具有重要的捕食者调节树木上的食草动物的功能。

To elucidate the species composition, abundance and spatial distribution of ants in the forest canopy of a tropical rain forest in Borneo, ant abundance were censused in the forest canopy of 15 tree species several times in the dipterocarp forest at Lambir National Park in Sarawak, Malaysia, using the system for observation of forest canopy there. In addition, to analyze the effects of ants on the herbivores, herbivore abundance and herbivory damage on leaves of the trees were also censused. Moreover, the effects of presence of epiphytes and aerial soil in the forest canopy on the availability of nest sites for ants were studied in the field.The results suggested that few species of ants utilize space both on the ground and on trees as their home range, that spatial distribution of ant species in the forest canopy is rather stable, and that particular ant species prefer the forest canopy or epiphytes for their nest sites. A few ant species that usually use the ground surface as their home range were observed to expand the range onto the surface of the tree trunk temporarily, and ant species that settle in the domatia of some epiphytes were often observed to be dominant in the forest canopy. The home ranges of these two types of ant species showed little overlap spatially, and were likely to have indirect influences on the spatial distribution of the other species in the forest canopy. Thus, it is presumed hat there is strong interspecific competition in the ant community in the forest canopy. The data suggest the possibility that ants that colonize epiphytes might regulate the abundance of lianas and other epiphytes and indirectly affect the spatial distribution of the other ants through the regulation. The data on the relations between herbivory damage and ant abundance suggest that these ant species might significantly function as predator regulating herbivores on the trees.