海南新村湾海菖蒲TN和TP含量时空变化及其对营养负荷的响应

以海南新村湾海草床优势种之一的海菖蒲(Enhalus acoroides)为研究对象,于2005年7月、10月和2006年1月,分3个季度对网箱养殖区、中间过渡区和对照区海菖蒲不同组织的TN、TP含量的时空变化特征进行了研究,初步探讨了其对营养负荷的响应。结果表明:(1)新村湾海水和沉积物间隙水DIN含量,呈现出网箱养殖区中间过渡区对照区的显著趋势。(2)海菖蒲根、茎和叶在3个季度中的TN含量范围分别为:0.576%~1.544%、0.803%~2.480%和1.796%~3.200%;TP含量分别为:0.053%~0.175%、0.073%~0.197%和0.183%~0.413%。(3)海菖蒲不同组织TN、TP含量,均显示叶茎根的显著趋势;海菖蒲不同组织TN含量呈现秋、冬季夏季的趋势,TP含量随季节变化趋势各有不同。(4)海菖蒲根和叶的TN含量,有由网箱养殖区向对照区递减的趋势,与其所在样区海水和沉积物间隙水DIN含量呈显著正相关;海菖蒲TP含量,普遍显示出网箱养殖区比中间过渡区和对照区显著大的趋势,但与海水和间隙水PO4-P的含量没有明显的关系。(5)N/P计算结果表明,新村湾海菖蒲的生长主要受N的限制。

Spatiotemporal variation of TN & TP contents in Enhalus acoroides and responses to nutrient load in Xincun Bay,Hainan

The characteristics of spatiotemporal variation of TN & TP contents in the different tissues of dominant species-Enhalus acoroides-of sea-grass bed in Xincun Bay,Hainan,China,were studied,in 3 seasons from 2005 Jul.to 2006 Jan.The DIN concentration was decreased from the cage culture area to control area significantly.TN contents of different tissues (root,rhizome and leaf) in E. acoroides were characterized in 0.576%～1.544,0.803%～2.480% and 1.796%～3.200%,respectively,and TP contents were 0.053%～0.175%,0.073%～0.197% and 0.183%～0.413%,respectively.TN & TP contents in the different tissues of Enhalus acoroides showed the trends of leaf > rhizome > root.The temporal variation trend of TN contents in E. acoroides was autumn & winter > summer,while TP contents in the different tissues of E. acoroides showed the different temporal variation trends.TN contents in roots & leaves of E. acoroides were decreased significantly from the cage culture area to the control area.It showed the obvious positive correlation between TN contents in roots & leaves of the plant and DIN concentrations in water column.TP contents in the different tissues of E. acoroides were characterized by much higher contents in the cage culture area than the other two sampling sites,but no certain correlation between TP contents in E. acoroides and P concentration in water column were found.According to the results of N/P,E. acoroides in Xincun Bay was controlled by N nutrient.