摘要
采用1992年Ruttenberg连续提取法(SEDEX)将黄东海陆架区沉积物中的磷分为交换态磷(Ex-P),Fe结合态磷(Fe-P),自生磷(Au-P),碎屑磷(De-P),有机磷(Or-P),分析了各形态磷的平面和垂直分布特征;利用沉积物年代序列测定的结果,探讨了柱状沉积物中不同形态磷的含量变化,并进一步分析了该区域磷形态的生物可利用性。结果表明,黄东海陆架区表层沉积物各形态磷平均含量为:Au-P(140.72μg/g)>De-P(59.23μg/g)>Or-P(32.69μg/g)>Fe-P(29.91μg/g)>Ex-P(5.92μg/g);各形态磷在沉积时间序列上分布不同,反映了不同时期人类活动和气候环境等因子对磷埋藏量影响的不同,其中Au-P在长江口H1-18站位含量比南黄海中部3个站位要低得多;调查区表层潜在生物有效磷为13.55%左右,仅仅占沉积磷中的一小部分。
Phosphorus is the most important limiting factor in nutrient cycling.It is also the key element controlling primary production in aquatic environments.Sediments act as both a sink and a source of phosphorus because of continuous transport of phosphorus species across the sediment-water interface.Phosphorus is intimately involved in both the terrestrial and marine biogeochemical cycles.However,not all fractions of phosphorus in sediments are released to the overlying water.Therefore the effects of phosphorus in sediments in promoting aquatic environment eutrophication can be more efficiently evaluated by studying phosphorus fractions,rather than total phosphorus（TP）.In this study,the forms and bioavailability of phosphorus in the sediment were analyzed by means of SEDEX（Ruttenberg KC） to determine the geochemical characteristics of phosphorus in the Huang Dong Hai continental shelf.According to this method,there are five types of phosphorus： iron-phosphorus（Fe-P）,organic-phosphorus（Or-P）,detritus-phosphorus（De-P）,exchangeable-phosphorus（Ex-P）,and autologous-phosphorus（Au-P）.They differ from each other in occurrence,origin and geochemical features.The horizontal and vertical distribution of six forms is presented.The profiles of age deposition were also investigated to reveal changes in the contents of the different phosphorus forms over about two hundred years.The rank order of the contents of phosphorus fractions in the surface sediment was Au-P（140.72 μg/g） ＆gt; De-P（59.23 μg/g） ＆gt; Or-P（32.69 μg/g） ＆gt; Fe-P（29.91 μg/g）＆gt; Ex-P（5.92 μg/g）.The contents of Au-P and Or-P decreased from offshore to the open sea,and values for De-P were uniformly distributed over the whole sea area.High contents of TP and Ex-P were present in the Yangtze estuary area.TP,Fe-P,Or-P,De-P,Au-P and Ex-P contents in the sediments were in the range 310.23—941.78μg/g,5.46—58.11μg/g,4.87—80.57μg/g,12.68—282.15μg/g,31.86—271.38μg/g,and 1.32—20.95μg/g,respectively.The vertical distribution of the different fractions of phosphorus at four sampling stations varied.The distribution of different phosphorus fractions in different sediments reflected changes in the early diagenesis of phosphorus.The concentration of Au-P in H1-18 was much lower than at the other three stations.In the study area,the relative contributions of Fe-P,Ex-P,and Or-P were 5.96%,1.18%,and 6.51% of TP,respectively.Fe-P is considered to be the most labile fraction of phosphorus fraction in the sediments.It will change when the oxidation-reduction environment changes in the surface sediments.Fe-P can be used to determine the source of phosphorus and indicate the extent of environmental pollution.Or-P can be released during the decomposition of organic matter in the early diagenetic process,and even convert to other forms of phosphorus.When organic matter degrades,the phosphorus is released into the overlying water.Consequently,the degradation of Or-P is an important process in its influencing of the contents of phosphorus fractions in sediments.Ex-P is influenced by particle size of the sediments and released into the overlying water mainly through ion exchange.Hence it is important to understand under what conditions phosphorus can be changed from one fraction into another and phosphorus in sediments can be released into the overlying water.Fe-P,Ex-P,and Or-P are biologically available fractions of phosphorus in our study area.The results showed that potentially biological available phosphorus accounted for 13.55% of the total phosphorus.
出处
《生态学报》
CAS
CSCD
北大核心
2013年第11期3509-3519,共11页
Acta Ecologica Sinica
基金
国家重点基础研究发展计划项目(2006CB400007)
中央级公益性科研院所基本科研业务费专项资金(20603022013003)
关键词
黄东海陆架区
沉积物
磷形态
年代序列
生物可利用性
Huang Dong Hai continental shelf
sediment
phosphorus forms
chronosequence
bioavailability
