Long-term evolution of shrub prescribed burning effects on topsoil organic matter and biological activity in the Central Pyrenees (NE-Spain).

Since the last half of the 20th Century, scrubs have been invading subclimatic grasslands in the montane and subalpine stages of Spain due to the decrease of the grazing activity. This shrub encroachment reduces biodiversity and the ecopastoral value of the region and leads to the accumulation of woody fuel, which represents a high fire risk. To control the encroachment, prescribed burnings are performed but their effects on soils over the years are still undetermined.