Anthropogenic disturbance and plant drivers shape multitrophic arthropod dynamics in urban ecotones : evidence from urban edge

Abstract

Arthropods maintain key ecosystem functions, and yet, remarkable reductions have been documented among various arthropod groups. Urban edges refer to dynamic ecosystems that serve as refuges for huge numbers of arthropods while being strongly influenced by anthropogenic disturbance. However, understanding how different facets of habitat heterogeneity, especially anthropogenic disturbance, affect various arthropod groups in urban edges remains limited. To tackle this problem, we monitored arthropod abundance, density, and diversity of four trophic levels and two ecosystem services groups of 288 sampling points distributed alongside the urban edges of Dexing city, China. First, we observed that anthropogenic disturbance negatively affected order- and trophic-level arthropod diversity but did not explain the loss of arthropod abundance and density, except those of predators and herbivores. Second, we revealed that plant abundance produced trophic-specific abundance changes in arthropods except omnivores, but only herbivore abundance increased with plant diversity. Finally, our results suggest that the top-down control that predators exert on herbivores was not significant in urban edges, but the anthropogenic drivers of habitat fragmentation in urban edges explained the decrease in pollinator diversity. We revealed the group-specific trends of arthropods living in urban edges to anthropogenic disturbance and explained the importance of plants in shaping multitrophic diversity and ecosystem multifunctionality. Thus, group-specific heterogeneity must be considered in the investigation of arthropod communities in urban edges.