Structure of ant assemblages in planted poplar (Populus alba) forests and the effect of the Common milkweed (Asclepias syriaca)

Abstract

Besides changes in vegetation during succession, the regular disturbance can be also responsible for the alteration of arthropod assemblages in planted forests, especially when the disturbance allows the establishment of non-native plant species. In our study, we investigated the structure of ant assemblages in plantations of different aged poplar forests (Populus alba) infested with the invasive common milkweed (Asclepias syriaca). Our results showed that the dispersion pattern of colonies was mostly regular with higher interspecific neighbour distances in the younger forests and higher intraspecific neighbour distances in the older forests. In the younger forests, most colonies nested in milkweed stems, while in the older forests colonies used more types of nesting sites and were mostly found in the soil and litter. These findings suggest that depending on whether suitable sites for nesting are limited or not, the importance of intra- and interspecific competition may vary among the different aged forests. The high abundances of milkweed thus can lead to the significant alteration of local ant assemblages, especially in the earlier successional stages of the forests.