| 引用本文: | 张运林,冯胜,马荣华,刘明亮,秦伯强.太湖秋季真光层深度空间分布及浮游植物初级生产力的估算.湖泊科学,2008,20(3):380-388. DOI:10.18307/2008.0319 |
| ZHANG Yun-lin,FENG Shen,MA Rong-hua,LIU Ming-liang,QIN Bo-qiang.Spatial pattern of euphotic depth and estimation of phytoplankton primary production in Lake Taihu in autumn 2004. J. Lake Sci.2008,20(3):380-388. DOI:10.18307/2008.0319 |
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| 摘要: |
| 基于2004年10月对全湖67个采样点水下光合有效辐射(photosynthetically active radiation:PAR)和各光学活性物质浓度的测定,分析了真光层深度的空间分布及其影响因素.利用实测的叶绿素a浓度,真光层深度,PAR强度,由水温计算得到的最佳固碳速率以及由经纬度计算的日照周期等,在垂向归纳模型(vertically generalized production model:VGPM)的支持下估算了全湖秋季浮游植物初级生产力.真光层深度的变化范围为0.37-5.27m(均值为1.52±1.06m),高值出现在东太湖、胥口湾、东西山之间等水生植物分布茂盛的草型湖区,而在梅梁湾、湖心区以及西南面的开阔湖区真光层深度均较小.回归分析显示,真光层深度主要受制于非色素颗粒物浓度,浮游植物和溶解性有机物的贡献相对要小得多.叶绿素a浓度和VGPM模型估算的浮游植物初级生产力变化范围分别1.21-53.59μg/L、77.4-2484.9mg/(m2·d),其时空分布基本一致,高值出现在富营养化的藻型湖区梅梁湾,低值出现在胥口湾和西南开阔湖区.VGPM模型和经验模式对比结果显示两者值比较接近并存在显著相关(r2=0.79,p<0.0001),两类模型全湖的均值分别为694.5±492.0、719.8±315.4mg/(m2·d),但由于VGPM模型考虑到真光层深度、温度、PAR强度以及日照周期对初级生产力的影响,其变化范围明显大于经验模型,也更能反映初级生产力的空间变化. |
| 关键词: 太湖 真光层深度 VGPM模型 叶绿素a 浮游植物初级生产力 |
| DOI：10.18307/2008.0319 |
| 分类号: |
| 基金项目:中国科学院知识创新工程方向性项目(KZCX2-YW-419);国家自然科学基金项目(40730529,40671138);江苏省自然科学基金项目(BK2006580)联合资助 |
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| Spatial pattern of euphotic depth and estimation of phytoplankton primary production in Lake Taihu in autumn 2004 |
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ZHANG Yun-lin1, FENG Shen1, MA Rong-hua1, LIU Ming-liang2, QIN Bo-qiang1
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1.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, P.R.China;2.Nanjing Agriculture University, Nanjing 210095, P.R.China
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| Abstract: |
| Based on the underwater photosynthetically active radiation (PAR) profile measurement and the concentrations of the optically active substances, the spatial patter and affecting factors of euphotic depth in Lake Taihu are discussed. Phytoplankton primary production (PPeu) of all the lakes in autumn 2004 is estimated using the vertically generalized production model (VGPM) based on measured surface chlorophyll-a (Chl.a) concentration, euphotic depth, water temperature, PAR at the water surface, photoperiod and water depth. Euphotic depth ranges from 0.37 to 5.27m with a mean value of 1.52±1.06 m. The higher euphotic depth appears in the macrophyte-dominated lake regions such as East Lake Taihu, Xukou Bay and water area between Xishan and Dongshan Islands. In contrast, the lower euphotic depth is found in algal-dominated lake region such as Meiliang Bay and the southwestern open water. The regression analyses show that euphotic depth is mainly controlled by nonpigment particle matter, next to phytoplankton and chromophoric dissolved organic matter (CDOM). Nonpigment particle matter can explain 96.7% variation of euphotic depth. The ranges of Chl.a concentration and estimated PPeu are 1.21-53.59μg/L, 77.4-2484.9mg/(m2·d), respectively. The estimated daily mean PPeu distribution coincides closely with that of Chl.a concentration. Higher Chl.a and PPeu values are recorded in Meiliang Bay and lower values are found in Xukou Bay or southwestern open water. There is a good correlation between VGPM PPeu and primary production from the empirical model (PPem)(r2 = 0.79, p<0.0001). Daily meaneu and PPem of all the lakes are 694.5±492.0, 719.8±315.4mg/(m2·d), respectively. Although the ranges of the two methods differ, the mean values are very close. PPeu more accurately captures spatial variation by considering the effect of euphotic depth, water temperature, surface PAR and photoperiod on PP. |
| Key words: Lake Taihu euphotic depth VGPM model chlorophyll-a phytoplankton primary production |
