摘要：Root productivity, estimated by growth into plastic (16 mm2 mesh) cylinders filled with soil free from roots, was 560 g. m-2 and 565 g. m-2 in a low altitude grassland (450 m sm) and a a high altitude grassland (850 m sm), respectively. Peaks of productivity were registered in spring in the low site and in spring and summer in the high site. Biomass losses dominated in summer and fall in both grasslands. 90% of annual production dissapeared at, the low grassland, and 42% at the high grassland. 60-67% of root biomass was concentrated in the top 10 cm of soil. Peaks of biomass were 645 ± 85.8 g. m-2 and 477 ± 37. 7 g. m-2 at the low and high altitude grasslands, respectively, and both were registered in the spring. The differences observed in these functional aspects of these grasslands might be attributed to their different species composition. The low-altitude grassland was dominated by cool-season grasses, while the high-altitude grassland was dominated by warm-season grasses
