Organic Carbon Stored in the Aerial Phytomass of Fire-threatened Andean Grassland Species

Abstract

The practice of burning Andean grasslands in uncontrolled conditions and dry seasonal periods affects the sustainability of the ecosystem with the loss of native grasslands species with superficial roots, the volatilization of organic matter and superficial soil nitrogen, and greater susceptibility to wind and rain erosion, which affects the forage supply of grazing areas that affect the economy of the cattle rancher in addition to emitting abundant CO₂ into the atmosphere. The objective was to quantify the loss of organic carbon contained in the aerial phytomass of burned grasslands and the dynamics of recovery of their shoots, for which seven grasslands with different dominant species and the exclusion of grazing were chosen from five plots of 900 m² with five subplots of 64 m², whose aerial phytomass was harvested, and the shoots were measured in their leaf height for nine months. As a result, variable amounts of carbon were obtained according to dominant grassland species for p: 0.001 from 5.02±1.05 to 20.02±0.95 t/ha, equivalent from 22.09 to 73.47 t.CO₂/ha. The recovery of shoot phytomass barely reached 37.32% to 55.94% concerning the initial amount obtained in the mother plants. It was concluded that each grassland has its performance of storage and recovery of stored carbon and the findings should be cause for reflection and be the basis for public policies to promote the protection of grasslands.