Soil organic carbon in northern Spain (Galicia, Asturias, Cantabria and País Vasco)
- Rosa Calvo de Anta 1
- Elías Luis Calvo 1
- Francisco Casás Sabarís 1
- Juan Manuel Galiñanes Costa 1
- Natividad Matilla Mosquera 1
- Felipe Macías Vázquez 1
- Marta Camps Arbestain 1
- Noemí Vázquez Garcí 1
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1
Universidade de Santiago de Compostela
info
ISSN: 2253-6574
Ano de publicación: 2015
Volume: 5
Número: 1
Páxinas: 41-53
Tipo: Artigo
Outras publicacións en: Spanish Journal of Soil Science: SJSS
Resumo
The soil organic carbon content was analyzed in more than 7,000 soil samples under different land uses, climates and lithologies from northern Spain (Galicia, Asturias, Cantábria y País Vasco). GIS maps (1:50 000) were made of the % SOC and SOC stocks. The % SOC varies according to land use (higher in forest and scrub soils and lower in agricultural soils) and climate, and there is a highly significant correlation between SOC content and mean annual precipitation. There are significant differences between the soils of Galicia/Western Asturias (GAw) and those of the rest of the study area (Central and Eastern Asturias, Cantabria and País Vasco) (AceCV), although these are neighbouring regions. In forest and/or scrub soils with a udic soil moisture regime, in GAw, the SOC is usually > 7% and the average stocks 260 t ha-1 (0-30 cm), and >340 t ha-1 (0-50 cm) in soils with thick organic matter rich horizons (> 40 cm); these values greatly exceed the average contents observed in forest soils from temperate zones. Under similar conditions of vegetation and climate in soils of AceCV the SOC average is 3% and the mean stocks 90-100 t ha-1 (0-30 cm). The andic character of acid forest soils in GAw and the formation of C-Al,Fe complexes are pointed out as the SOC stabilization mechanism, in contrast to the neutral and calcareous soils that predominate in AceCV, where the main species of OC are easily biodegradable.