Understanding the relationship between biodiversity and ecosystem function is central to the Global Change and Terrestrial Ecosystem (GCTE) project as well as to ecosystem ecology in general. Productivity and nutrient maintenance, both critical ecosystem functions, can be measured in relation to species diversity to test how ecosystem functions are affected by species diversity. We studied changes in species diversity and productivity along elevational gradients in alpine meadow grasslands to assess the influence of changing species diversity on productivity.The results show a significant unimodal pattern of species diversity across the elevation gradient with species diversity highest at mid-elevations. Maximum species diversity occurred at intermediate levels of productivity and species richness. Above-ground biomass decreased with increasing elevation and below-ground biomass was greatest at low and high elevations and lowest at mid-elevations. Below-ground biomass varied during the growing season and vertically within the soil profile: maximum underground biomass occurred at the beginning and end of plant growing and was distributed primarily in the top 0-10 cm of soil.