Soil organic carbon along an altitudinal gradient in the Despe?aperros Natural Park, southern Spain

摘要

Soil organic carbon (SOC) is extremely important in the global carbon (C)cycle as C sequestration in non-disturbed soil ecosystems can be a C sink andmitigate greenhouse-gas-driven climate change. Soil organic carbon changes inspace and time are relevant to understand the soil system and its role in theC cycle. This is why the influence of topographic position on SOC should bestudied. Seven topographic positions from a toposequence between 607 and1168 m were analyzed in the Despe?aperros Natural Park (Jaén, SWSpain). Depending on soil depth, one to three control sections (0–25, 25–50and 75 cm) were sampled at each site. The SOC content in studied soils wasbelow 30 g kg?1 and strongly decreases with depth. These results wererelated to the gravel content and to the bulk density. The SOC content fromthe topsoil (0–25 cm) varied largely through the altitudinal gradientranging between 27.3 and 39.9 g kg?1. The SOC stock (SOCS) variedbetween 53.8 and 158.0 Mg ha?1 in the studied area, which had been clearlyconditioned by the topographic position. Therefore, results suggest thatelevation should be included in SOCS models and estimations at local andregional scales.