TY - JOUR
T1 - Phosphorus content in five representative landscape units of the Lomas de Arequipa (Atacama Desert-Peru)
AU - Fabre, André
AU - Gauquelin, Thierry
AU - Villasante Benavides, Jose Francisco
AU - Ortega, Aldo
AU - Puig, Henri
PY - 2006/1/31
Y1 - 2006/1/31
N2 - Phosphorus forms and content were studied in soils of the Lomas de Arequipa (Atacama desert, Peru) using a fractionation method. These Lomas are small hills periodically submitted to the El Niño-Southern Oscillation (ENSO) which causes heavy rainfall. Sample soils were randomly selected in five landscape types characterized by vegetation: cactaceae (Cac), cactaceae and herbaceous (CacHerb), shrubs (Shr), trees with cover < 60% (Tree) and shrubs or trees with cover > 60%) (ShrTree). All the soils were strongly acidic and classified as loamy sand, sandy loam or silt loam. Organic carbon content was under 1% in Cac or CacHerb, then increased strongly in ShrTree (6.50%). Considering phosphorus, all the forms (labile as well resistant forms) increased markedly from Cac soils to ShrTree soils. In all the soils, the labile forms (Resin-P: range 45-105 μg g- 1; NaHCO3-Pi: 23-123 μg g - 1; or NaHCO3-Po: 10-122 μg g- 1) were very high. These high phosphorus contents were attributed to the specific climatic conditions of the Lomas that feature a long period of vegetation dormancy (very dry period) and a short period of growth, following ENSO-associated precipitation. We suggested that during the dry period, plant decay and microbial cells death lead to release and accumulation of labile P in the soil, the rainfall wetting the soil, permitting vegetation growth. In this respect, the Lomas climatic conditions contribute to soil fertility, especially as labile forms of phosphorus are chiefly concerned.
AB - Phosphorus forms and content were studied in soils of the Lomas de Arequipa (Atacama desert, Peru) using a fractionation method. These Lomas are small hills periodically submitted to the El Niño-Southern Oscillation (ENSO) which causes heavy rainfall. Sample soils were randomly selected in five landscape types characterized by vegetation: cactaceae (Cac), cactaceae and herbaceous (CacHerb), shrubs (Shr), trees with cover < 60% (Tree) and shrubs or trees with cover > 60%) (ShrTree). All the soils were strongly acidic and classified as loamy sand, sandy loam or silt loam. Organic carbon content was under 1% in Cac or CacHerb, then increased strongly in ShrTree (6.50%). Considering phosphorus, all the forms (labile as well resistant forms) increased markedly from Cac soils to ShrTree soils. In all the soils, the labile forms (Resin-P: range 45-105 μg g- 1; NaHCO3-Pi: 23-123 μg g - 1; or NaHCO3-Po: 10-122 μg g- 1) were very high. These high phosphorus contents were attributed to the specific climatic conditions of the Lomas that feature a long period of vegetation dormancy (very dry period) and a short period of growth, following ENSO-associated precipitation. We suggested that during the dry period, plant decay and microbial cells death lead to release and accumulation of labile P in the soil, the rainfall wetting the soil, permitting vegetation growth. In this respect, the Lomas climatic conditions contribute to soil fertility, especially as labile forms of phosphorus are chiefly concerned.
KW - Atacama desert
KW - ENSO
KW - Lomas
KW - Peru
KW - Phosphorus fractionation
KW - Soils
UR - http://www.scopus.com/inward/record.url?scp=32044444422&partnerID=8YFLogxK
U2 - 10.1016/j.catena.2005.10.004
DO - 10.1016/j.catena.2005.10.004
M3 - Artículo
AN - SCOPUS:32044444422
VL - 65
SP - 80
EP - 86
JO - Catena
JF - Catena
SN - 0341-8162
IS - 1
ER -