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磷(P)是控制水体生态系统生产力的重要元素,了解陆地与水体间P的迁移特征,是了解控制水体生态系统中P有效供给的重要途径.本研究选择青藏高原东缘贡嘎山海拔2800m左右峨眉冷杉林带中一小湖泊-草海子及其流域,通过对流域内土壤、湖泊沉积物中P的形态组成分析,探讨流域内P的形态组成及其迁移特征.结果表明.草海子流域内土壤成土母质中的磷以Ca-P为主,表层土壤中的磷以Al、Fe结合态为主,占总磷的49%~80%,而湖泊沉积物中Al、Fe结合态P下降到46%左右.在成土作用及植物吸收的过程中P由土壤剖面下部向上迁移,迁移的主要形态为树脂提取态(或称可交换态,R-P),而R-P还是由陆地向水体迁移的主要形态P.土壤的Al、Fe结合态P难以释放转化,因此少有随地表径流迁移向湖泊. “,”Phosphorus (P) ecosystem. Understanding is often the critical limiting nutrient controlling the productivity of aquatic the linkages between terrestrial and aquatic P dynamics is essential to defining the mechanisms governing P availability. We used P fractionation techniques to investigate the P fractions and its migrating in a Abies forested watershed, at elevation about 2800 m asl, Gongga Mountain, Southwest China. The dominant P fraction is aluminum (A1) and ferrum (Fe) combined fraction, which accounts for 49% to 80% of total P in the surface soil, while in lake sediment A1 and Fe combined fractions account for 46%. During the pedogenesis and plant assimilation, P is migrated from the bottom of soil profile upward. R-P ( Exchangeable P) is the dominant fraction for migrating from bottom upward, as well as from terrestrial soil to water. A1 and Fe combined P is difficult to be decomposed so that it is seldom been transported by the runoff from the terrestrial soil to lake.