Phosphorus fractions and profiles in the sediment of shallow Danish lakes as related to phosphorus load, sediment composition and lake chemistry
Phosphorus fractions and profiles in the sediment of shallow Danish lakes as related to phosphorus load, sediment composition and lake chemistry
复制标题
DOI：
10.1016/0043-1354(95)00251-0
复制
发表时间：
1996-04
期刊：
影响因子：
12.8
通讯作者：
M. Søndergaard;J. Windolf;E. Jeppesen
中科院分区：
文献类型：
--
作者：
M. Søndergaard;J. Windolf;E. Jeppesen
在丹麦32个浅水中-富营养化湖泊中测定了沉积物干重（DW）、烧失量（LOI）、总铁（Fe）、总氮（TN）、钙（Ca）、总磷（TP）、NH 4Cl-P、NaOH-P、HCl-P和Res-P的深度剖面，并与外部磷负荷（Pex）、湖水磷和浮游植物生物量的数据进行了比较。表层沉积物TP与Pex（g P m− 2 y −1）和Fe（mg Fe g−1DW）高度正相关（TP = 0.92 + 0.23 Pex + 0.031 Fe，r2= 0.68，P < 0.0001），但与其他分析参数无关或仅弱相关。沉积物中NaOH-P与Fe（r2= 0.43）、TP（r2= 0.75）呈显著正相关，HCl-P与Pex（r2= 0.68）、TP（r2= 0.28）和浮游植物生物量（r2= 0.35）呈显著正相关，而与Ca无相关性。平均4%的表层沉积物TP是NH_4Cl-可提取的，35%的NaOH-可提取的和20%的HCl-可提取的，其余41%是残余磷（Res-P）。在沉积物深度低于50 cm时，Res-P含量较高（占TP的63%），而NaOH-P含量仍相当高（占TP的21%），这表明铁结合磷有显着的永久沉积。在大多数沉积物中，与20-30 cm以下的深度相比，记录到较高的表面Res-P和NaOH-P。NaOH-P梯度的存在下，即使在湖泊中，P-湖和人为影响低，表明沉积后流动性的磷可能会发生。Res-P梯度表明，沉积物上部10-20 cm的有机结合磷的大部分最终被矿化和溶解。
Depth profiles of sediment dry weight (DW), loss on ignition (LOI), total iron (Fe), total nitrogen (TN), calcium (Ca), total phosphorus (TP), NH4Cl-P, NaOH-P, HCl-P and Res-P were measured in 32 shallow meso- to hypertrophic Danish lakes and the data compared with that for external phosphorus load (Pex), lake water phosphorus and phytoplankton biovolume. Surface sediment TP was highly and positively correlated to Pex (g P m−2y−1) and Fe (mg Fe g−1DW) (TP = 0.92 + 0.23 Pex + 0.031 Fe, r2= 0.68, P < 0.0001), but not or only weakly related to the other parameters analyzed. NaOH-P in the sediment was significantly and positively correlated to Fe (r2= 0.43) and TP (r2= 0.75), while HCl-P was correlated to Pex (r2= 0.68), TP (r2= 0.28) and to phytoplankton biovolume (r2= 0.35), but not to Ca. On average 4% of the surface sediment TP was NH4Cl-extractable, 35% NaOH-extractable and 20% HCl-extractable, with the remaining 41% being residual phosphorus (Res-P). At sediment depths below 50 cm the Res-P fraction was greater (63% of TP), while there was still considerable NaOH-P (21% of TP), thus indicating a significant permanent deposition of iron-bound phosphorus. In most sediments a higher surface Res-P and NaOH-P were recorded as compared to depths below 20–30 cm. The presence of a NaOH-P gradient, even in lakes in which P-lake and anthropogenic impact were low, suggests that post-depositional mobility of phosphorus may occur. The Res-P gradient indicates that a major part of the organically bound phosphorus in the upper 10–20 cm of the sediment eventually is mineralized and dissolved.