1. Phosphorus fractions and alkaline phosphatase activity in sediments of a large eutrophic Chinese lake (Lake Taihu).
- Author
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Zhou, Yiyong, Song, Chunlei, Cao, Xiuyun, Li, Jianqiu, Chen, Guoyuan, Xia, Zhuoying, and Jiang, Pinghong
- Subjects
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PHOSPHORUS , *ALKALINE phosphatase , *SEDIMENT analysis , *EUTROPHICATION , *SPATIO-temporal variation , *SEASONAL variations in biogeochemical cycles - Abstract
Spatial, vertical, and seasonal variations in phosphorus fractions and in alkaline phosphatase activity (APA) were investigated in sediments in a large-shallow eutrophic Chinese lake (Lake Taihu) in 2003–2004. The phosphorus content was highest in the most seriously polluted lake area. Iron-bound phosphorus (Fe(OOH)∼P) dominated (47% on average) among the phosphorus fractions determined according to Golterman (Hydrobiologia 335:87–95, 1996). Notably, organically-bound P comprised a further significant additional portion (acid-soluble + hot NaOH-extractable organic P = 25%), which was highest at the most polluted sites. The Fe(OOH)∼P content was the lowest in spring (April, 2004), suggesting that degradation of organic matter led to the release of iron-bound phosphates. Sediment APA showed a significant positive relationship with both organically-bound P and Fe(OOH)∼P. Consequently, organically-bound P is an important portion of the sediment phosphorus in Lake Taihu. It is mainly derived from freshly-settled autochthonous particles and from external discharges. Organically-bound P induces APA and may lead to the release of bioavailable phosphates from the organic sediments, thereby accelerating lake eutrophication. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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