Abstract:

Background & Aim Insects are one of the most abundant biological components in grassland ecosystems, playing a critical role in the structure and function of the grassland food web. A systematic summary is lacking of the response patterns and regulatory mechanisms of insect communities due to the increasing severity of global nitrogen deposition.

Review results This paper summarizes relevant research in recent years and finds that nitrogen deposition can exert positive, negative, or neutral effects on insect abundance and diversity. The direction of its impact mainly depends on the duration and intensity of nitrogen deposition, different insect taxa, and types of grasslands. Nitrogen deposition can affect the quantity and quality of food resources, abiotic conditions, and biotic interaction of insect communities through various pathways such as changing plant diversity, plant biomass, plant nutrition, community composition and structure, microclimate, and breeding habitat.

Suggestions & Perspectives In the future, research should strengthen the understanding of (1) the multi-trophic interactions of grassland insects; (2) the interaction between nitrogen deposition and other global change factors; (3) the examination on a larger temporal and spatial scale; and (4) the role of key functional traits of insects to explain and predict the response to nitrogen deposition. A benefit from this study is to understand the impact of nitrogen deposition on grassland insect communities and provide theoretical support for the protection of grassland insect diversity due to global changes.

Key words: nutrient enrichment, nitrogen addition, global change, arthropods, insect community, food web