Recovery of degraded pastures through temporary closures

© 2000 Universidad Nacional Mayor de San Marcos. All rights reserved. The impact of eliminating grazing on the recovery of degraded high elevation wet and dry Andean puna pastures is documented. In each ecosystem, areas of 625 m2 were fenced and 20 alpacas were grazed for 14 days to provide natural fertilisation prior to closure. After two years without grazing at the wet puna test si te at 4, 100 meters abo ve sea Jevel in Marampaqui, (Quíspicanchis, Ocongate, Cusco), biomass increased by 308%, plant cover grew by 16% and carrying capacity improved by 400% from 1.9 to 7 .6 animals per hectare. Pasture composition altered with the appearance of 13 new plant species, an 8% decrease in the desirable Alchemilla pinnata, a 71 % increase in the undesirable Calamagrostis vicunarum and a 50% decrease in the undesirable Aciachne pulvinata species, among others. At the dry puna test site at 4,300 meters above sea level in the community ofTítiri, (Mariscal Nieto, Moquegua), biomass increased by 27%, plant cover grew between 28 and 69%, and carrying capacity improved by 40% from 0.5 to O. 7 animals per hectare. A total of 6 desirable new species appeared and production of the desirable Alchemilla pinnata increased by 950%. Among the undesirable species, Calamagrostis vicunarum increased by 31 % and Astragalus sp. disappeared.