Effects of Pinus sylvestris var. mongolica afforestation on soil phosphorus status of the Keerqin Sandy Lands in China

摘要: Few studies have considered the effects of afforestation on soil phosphorus (P) status in semiarid regions such as Keerclin Sandy Lands China, though plantations been widely established P-deficient sandy soils to control wind-induced desertification. Phosphorus fractions and acid phosphomonoesterase (AP) activities were compared rhizosphere bulk (0-5 5-20cm) Under Mongolian pine (Pinus sylvestris L. var. mongolica Litv.) different ages (15, 22, 30 years old) under grasslands understand P behavior with plantation development find out major factors controlling cycling. Stand age processes had similar fractions. Labile inorganic phosphate absorbed aluminum iron oxides not affected by stand processes. Rhizosphere accelerated mineralization organic increasing microbial AP activities. Soil properties changed similarly development. In first 15 after afforestation, total P, calcium phosphate, labile biomass (MBP) concentrations, reduced sharply. About 73% reduction came from 24% solubilization phosphate. From 22 onward, decreased gradually MBP, increased greatly, whereas remained constant. The results suggest that pool was depleted development, especially early stage. As dominant form main source available associated biological controlled cycling plantations. To ensure sustainability plantations, it is imperative fertility conserved adding fertilizer, thinning, protecting litterfall. (c) 2006 Elsevier Ltd. All rights reserved.