School of Life Sciences, Liaoning University, Shenyang 110036, China.
Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
Ying Yong Sheng Tai Xue Bao. 2023 Jul;34(7):1975-1980. doi: 10.13287/j.1001-9332.202307.009.
To reveal the effects of nitrogen (N) inputs and mowing on the abundance and richness of insect community in meadow steppe, we investigated the abundance and diversity of herbivorous insects under four treatments in Inner Mongolia meadow steppe in August 2022, including control, N addition, mowing, and combined N addition and mowing. At a long-term control experimental platform, we collected insects using the vacuum sampling method. The results showed that N addition significantly increased the abundance of herbivorous insects, and mowing significantly decreased the abundance of herbivorous insects. Nitrogen addition significantly increased insect abundance in unmown condition but not in the mown condition. The responses of insect abundance at the community level to N addition were mainly driven by the dominant groups, Cicadellidae and Lygaeidae, which was affected by the abundance of Gramineae species. In contrast, their responses to mowing were the opposite. Both N addition and mowing did not affect the diversity of herbivorous insects. Our results indicated that the responses of herbivorous insect abundance to N inputs and mowing were directly regulated by food resources. With increasing food resource availability, the abundance but not the diversity of herbivorous insects increased, with stronger responses of dominant groups than subordinate ones.
为了揭示氮（N）输入和刈割对草原草甸昆虫群落丰富度和多度的影响，我们于 2022 年 8 月在内蒙古草原草甸调查了 4 种处理下（对照、氮添加、刈割和氮添加与刈割联合）食草昆虫的多度和多样性。在一个长期的对照实验平台上，我们采用真空取样法收集昆虫。结果表明，氮添加显著增加了食草昆虫的多度，刈割显著降低了食草昆虫的多度。氮添加在未刈割条件下显著增加了昆虫的多度，但在刈割条件下则没有。昆虫多度在群落水平上对氮添加的响应主要受优势类群（蝉科和盲蝽科）的驱动，这些类群受禾本科物种丰度的影响。相比之下，它们对刈割的响应则相反。氮添加和刈割都没有影响食草昆虫的多样性。我们的研究结果表明，食草昆虫多度对氮输入和刈割的响应受到食物资源的直接调节。随着食物资源的增加，食草昆虫的多度而不是多样性增加，优势类群的响应强于次要类群。
