干旱区生态环境知识资源中心

Semidesert grasslands of southern New Mexico have been replaced in this century with shrublands (chiefly creosote bush and mesquite). The Jornada Long-Term Ecological Research Program has been monitoring aboveground plant productivity, plant species composition, and other aspects of ecosystem function in 15 sites. Plant diversity differs significantly among vegetation types, with grasslands being the most diverse. Aboveground net primary productivity does not differ significantly among vegetation types. Productivity is correlated with plant species richness in some seasons; however, diversity has not been correlated with smaller fluctuation of production between years in the first few years of study. These results have implications for sustainable management of diversity and of productivity.