Dynamics of topsoil carbon stocks after prescribed burning for pasture restoration in shrublands of the Central Pyrenees (NE-Spain)

摘要: Prescribed burning has been recently readopted as a management practice in the Central Pyrenees (NE-Spain) to stop shrub encroachment processes and recover pasturelands. The immediate effects of prescribed on soil C stocks related biological properties their evolution short-to mid-term after were assessed. study was conducted during three autumnal burnings municipalities Buisan, Asin de Broto Yebra Basa. At each site, topsoil Ah horizon sampled at depths 0-1, 1-2 2-3 cm immediately before burning. Additionally, seasonal samplings every 6 months up one year case sites 24 months at Buisan site. total organic stock (SOCS) N (NS), microbial biomass (MBC), basal respiration (SR) β-D-glucosidase activity analyzed. maximum temperatures recorded surface 438 °C (Buisan), 768 °C (Asin) 595 °C (Yebra). significantly decreased SOCS (-52%), NS (-44%), MBC (-57%), SR (-72%) glucosidase (-66%) 0-1 cm depth, whereas fire had no direct sites. contrasting that observed among found be differences residence time. site plain slope under slow winds (<8 km h-1) rate 0.64 ha h-1, which produced greater impacts than sites, where spread rapidly (2.72 1.43 ha h-1, respectively). recovered unburned values 24 One burning, 60% higher those soils depth. all decreasing trend short- observed. From results it can concluded that: 1) are highly dependent environmental conditions, 2) mid-term, reduction incorporation ashes charred plant remains led an increase burned soils.