Heil Martin, Hilpert Andrea, Fiala Brigitte, Linsenmair K Eduard
Theodor-Boveri-Institut, Biozentrum, Zoologie III, Am Hubland, 97074, Würzburg, Germany.
Oecologia. 2001 Feb;126(3):404-408. doi: 10.1007/s004420000534. Epub 2001 Feb 1.
Tropical plants of different genera defend themselves via symbiotic ant colonies, which are housed and often nourished by their host plant. Many studies deal with the defensive effects of the ants, but none has linked the plants' investment in this type of defence to the size and defensive efficacy of the symbiotic ant colony. We show here that ant-food production by the obligate myrmecophyte, Macaranga triloba, is limited by nutrient supply. The colony size of the ants in untreated plants (which had not been affected by experiments in advance of colony collection and determination of food body production) was significantly correlated with the amount of food produced by their hosts, and the plants' level of leaf damage was significantly and negatively correlated with the number of inhabiting ant workers. Our study provides the first field data that show that nutrient availability can directly influence a myrmecophyte's investment in its ants. Further studies are needed to evaluate whether soil nutrient contents in general can be a factor that limits the ability of myrmecophytes to defend themselves indirectly by nourishing symbiotic ants.
不同属的热带植物通过共生蚁群进行自我防御，这些蚁群生活在宿主植物中，并常常由宿主植物提供养分。许多研究探讨了蚂蚁的防御作用，但没有一项研究将植物在这种防御方式上的投入与共生蚁群的规模和防御效能联系起来。我们在此表明，专性蚁栖植物三棱野桐的蚂蚁食物生产受到养分供应的限制。在未处理的植物中（即在蚁群收集和食物体产量测定之前未受到实验影响的植物），蚂蚁的蚁群规模与宿主产生的食物量显著相关，并且植物的叶片损伤程度与栖息的工蚁数量显著负相关。我们的研究提供了首个实地数据，表明养分有效性可直接影响蚁栖植物在其蚂蚁身上的投入。还需要进一步研究来评估土壤养分含量总体上是否可能是限制蚁栖植物通过滋养共生蚂蚁进行间接自我防御能力的一个因素。
