Ecosystem Analysis of the Tallgrass Prairie: Nitrogen Cycle

Abstract

Nitrogen cycling in tallgrass prairie was studied by using nitrogen content and concentration data for various ecosystem components on grazed and ungrazed tallgrass prairie in northeast Oklahoma. The seasonal dynamics of N in various plant parts was described, and the annual flow of N among different compartments was calculated. A simulation model was used to study the effect of grazing, fertilization, irrigation, and fire on nitrogen cycling. The results show that grazing, fertilization, and irrigation increase the nitrogen cycling rates. Annual spring fires reduce plant uptake and mineralization of N from plant parts, while mineralization of N from organic matter is increased.