Effect of urbanization on functional and behavioral traits of ant in forest and urban area

Urbanization is considered a major cause of biodiversity decline. Along with rapid human-induced environmental changes, the microclimate in fine-scale habitat becomes more unstable and fluctuated, which creates a harsh condition to local communities. Thus, the changes ultimately lead to a conceivable undermine of ecosystem services and functions. Ants serve as a significant ecosystem engineer and vital terrestrial consumer in a food web. However, their functional traits and behavior may change in response to alternation of local environment. In this study, we used functional traits distribution and behavioral preference of food particle size to assess the effect of urbanization on ant assemblage in forest and urban areas. Functional richness and divergence were higher in forest (Functional Richness =1.2189, Evenness =0.2871, Divergence =0.7461) compared to urban area (Functional Richness=0.0025, Evenness=0.2885, Divergence=0.6701). A shift of food particle size preference was also detected, in which ants in urban area tended to consume finer particle (0.84mm-1.68mm) when compared to those in forest area. Conversely, forest ants chose bigger particle (0.24mm-0.84mm) probably because of longer abundance-weighted mandible length. These suggested that functional traits structure in urban ant community was significantly homogenized. Analysis of trait-environment relationship showed that temperature was the main factor in both areas; while effects of humidity and light intensity on ant assemblage restricted only in urban. Overall, results showed a shrinkage of functional traits distribution in urban area, which indicated that numbers of ant specialists that contributed to ecosystem processing were filtered in the event of anthropogenic changes.