Diet influences rates of carbon and nitrogen mineralization from decomposing grasshopper frass and cadavers

作者：Fielding Dennis J^*; Trainor Ellen; Zhang Mingchu

来源：Biology and Fertility of Soils, 2013, 49(5): 537-544.

DOI：10.1007/s00374-012-0702-5

• Plant-herbivore interaction
• Nitrogen mineralization
• Nutrient cycling
• Soil incubation
• Herbivory
• Insect defoliation
• Alaska

Insect herbivory can produce a pulse of mineral nitrogen (N) in soil from the decomposition of frass and cadavers. In this study, we examined how diet quality affects rates of N and carbon (C) mineralization from grasshopper frass and cadavers. Frass was collected from grasshoppers fed with natural or meridic diets which varied in N content. Frass was also collected from naturally foraging grasshoppers. Nitrogen concentration of frass was directly proportional to diet N, but N content of cadavers was not affected by diet. Incubations of soil plus frass were performed at constant soil moisture and temperature (15A degrees C) for 28 days, after which levels of mineral N (KCl extract) were determined. About 44 % of C and N from the cadavers were mineralized after the 28-day incubation. Carbon mineralization of frass was not affected by diet or frass N but varied considerably among different food treatments: from 15 to 46 % of the C in frass was released as carbon dioxide. Generally, frass with C/N ratio greater than 20 resulted in net immobilization of N. Results suggest that much of the N in grasshopper frass and cadavers is labile and rapidly available for plants, depending on the quality of food consumed by the grasshoppers.

• 出版日期2013-7