EFFECTS OF ANTHROPOGENIC DISTURBANCES ON PARAMO VEGETATION IN PODOCARPUS NATIONAL PARK, ECUADOR

Abstract

Páramo, a form of tropical alpine vegetation, has experienced intense anthropogenic disturbances throughout the northern Andes, but relatively few studies have examined the disturbance ecology of this ecosystem. This article concerns the use of experimental techniques to quantify the effects of human disturbances on lower páramo vegetation in southern Ecuador. Beginning in January 1992, thirty-eight 3 × 2 m plots were inventoried at a site (3285 to 3384 m elevation) that includes both grass páramo and shrub páramo communities. Within the grass páramo, three different treatments were applied: eight plots were cut with a machete, eight were burned with gasoline, and eight were cut and burned; ten plots in the shrub páramo were cut only. The regeneration within these plots was monitored one year later. Within the grass páramo, “burned” plots experienced a higher rate of woody stem regrowth than did plots in the other treatments. “Cut and burned” plots experienced the lowest rate of woody stem regeneration and the greatest loss of species. In the shrub páramo, cutting alone resulted in the loss of rare woody species and an increase in frequency of common herbaceous species. [Key words: paramo, disturbance ecology, regeneration dynamics, Andes, Ecuador.]