A Bioeconomic Model of Cattle Stocking on Rangeland Threatened by Invasive Plants and Nitrogen Deposition
构建了一个生物经济模型，研究在入侵植物和氮沉降威胁下，牧场最优放牧密度如何取决于本地草与入侵者的竞争，以及氮水平如何影响过度放牧的界定。
Abstract Across western North America, invasive plant species and elevated levels of nitrogen are threatening the productivity of rangelands. A bioeconomic model of stocking cattle on these rangelands is used to show that optimal stocking depends on the competition between native grasses and the invaders. However, nitrogen deposition is important in determining the ultimate rangeland species composition. Endogenous changes in plant successional thresholds are due to the interplay of nitrogen deposition and stocking practices. Nonoptimal overstocking can create ecosystem niches for invaders where they would not have occurred at lower stocking rates, although what constitutes overstocking depends on the nitrogen levels.