Long-term Dynamics in Soil Field Available Nitrogen and Potentially Mineralizable Nitrogen in a Chihuahuan Desert Grassland at the Sevilleta National Wildlife Refuge, New Mexico (1989-2014)

Associated with a project that was based upon the assumption that nitrogen may limit net primary plant production in desert grasslands, this project began measuring available inorganic soil N and potentially mineralizable N of soils at two desert grassland locations. Both available N and potentially mineralizable N were greatest following a drought period in 1989, declined during wetter periods that followed and remained relatively stable until another extended drought period. After drought in 1995-6, both forms of soil N increased, indicating the potential for greater NPP following drought and lower potential NPP during periods of normal precipitation.

本项目基于“氮可能限制荒漠草原的植物净初级生产力（net primary plant production, NPP）”这一假设开展，在两处荒漠草原样地完成了土壤有效无机氮与土壤潜在矿化氮的测定工作。1989年干旱期结束后，有效氮与潜在矿化氮含量均达到峰值，在随后的湿润期有所下降，并在另一次长期干旱期来临前保持相对稳定。1995至1996年干旱事件过后，两类土壤氮含量均出现回升，这表明干旱后植物净初级生产力的提升潜力更高，而在正常降水期其提升潜力则相对较低。