Burning and grazing gradients in paramo vegetation: Initial ordination analyses

In the bunchgrass paramo at 3900-4200m elevation in Parque Nacional Natural Los Nevados, in the central cordillera of Colombia, vegetation patterns in relation to burning and grazing were characterised. Clustering and ordination techniques were applied to analyse variation of vegetation structure and floristic composition in relation to management variables. Zonal vegetation is dominated by species of Calamagrostis and the stem rosette Espeletia hartwegiana ssp. centro-andina. On moderate slopes the vegetation opens up under an intermediate grazing intensity. In these situations, coverage, height, and diameter of the bunchgrasses decrease, wheras percentage of bare soil and trampling impact increase. On more gentle slopes and flat terrains a short, matted grassland develops characterised by Calamagrostis coarctata and Lachemilla orbiculata. A list of species showing a positive or negative reaction to burning and grazing variables is presented.