کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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4399179 | 1306722 | 2009 | 8 صفحه PDF | دانلود رایگان |
The movement of phosphorus (P) from agricultural fields to streams and deposition in the nearshore of the lake presents a continuum of related physical and chemical properties that act to partition P into different physico-chemical fractions. We investigated changes in soil and sediment P fractionation as material was eroded from predominantly agricultural fields, transported via stream sediments, and deposited in a nearshore lake environment. Total phosphorus content of the soils and sediment decreased from field soils with an average concentration of 553.81 mg P kg− 1 to 202.28 mg P kg− 1 in stream sediments to 67.47 mg P kg− 1 in lake sediments. Significant changes in P fractionation occurred during erosion, transport, and deposition of the particulate or sediment phase. The fractionation of P within the soils and sediments changed significantly from aluminum and organic matter associated P dominant in field soils to calcium associated P dominant in nearshore lake sediments. Various physical and chemical processes appear to be responsible for these transformations which impact the mobility and bioavailability of P. A significant amount of P was lost from field soils as they were transported and deposited. This P has either become available to biota or deposited in deeper portions of the lake system. Ultimately, the impact of P export on the nearshore lake environment may be influenced by the changes in P fractionation that occurred during transport and deposition and by the influence of macrophytes on the biogeochemical cycling of P in the sediment.
Journal: Journal of Great Lakes Research - Volume 35, Supplement 1, 2009, Pages 56–63