MACROPHYTE BIOMASS, NUTRIENTS AND PRIMARY PRODUCTION OF A TROPICAL GLACIER RIVER IN THE ANDES

Abstract

 The objective of this research is to study the relationships between the biomass of the submerged aquatic vegetation, the nutrients, and the primary production in the Condoriri River. Field measurements were conducted to determine variations of physicochemical parameters, biomass, and nutrients in water and aquatic plants during dry and wet seasons. Macrophyte biomass had correlations of negative gradients with electric conductivity (EC) (R²=0.33, P<0.03) and phosphorus content (R²=0.47, P<0.01). Alkaline pH>7.5 and EC (132.5 μS·cm^-1) affected the growth of the aquatic plants. The nutrient loads during the wet season were related to high macrophyte biomass. Submerged aquatic vegetation influenced the river metabolism in both seasons. Primary production and macrophyte biomass exhibited a good agreement (R²=0.79).