| 引用本文: | 陈小林,陈光杰,刘园园,李蕊.云南45个湖泊硅藻-总磷转换函数及其定量重建评价.湖泊科学,2023,35(1):88-102. DOI:10.18307/2023.0105 |
| Chen Xiaolin,Chen Guangjie,Liu Yuanyuan,Li Rui.Evaluation of the quantitative relationships between diatom communities and total phosphorus (TP) in 45 lakes and their applications for TP reconstruction in Yunnan, Southwest China. J. Lake Sci.2023,35(1):88-102. DOI:10.18307/2023.0105 |
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| 摘要: |
| 20世纪中期以来随着流域开发的增强,营养物质的流域输出与水体富集导致云南湖泊出现了持续的富营养化过程,对高原湖泊的生物群落构建和生态系统健康产生了重要影响。区域尺度上云南湖泊的现代监测时间较短(如<20年),无法为湖泊生态恢复提供可靠的营养水平背景值。因此,应用古湖沼学方法建立硅藻群落与营养水平指标的定量模型可为污染湖泊的富营养化历史重建与修复目标建立提供重要的定量分析手段。本文选取云南地区45个湖泊开展了表层沉积物硅藻群落的空间分布特征分析,结合湖泊水体的环境变量数据开展了影响硅藻群落构建的环境梯度识别,识别出水体总磷(TP)是驱动硅藻群落空间变化的关键环境因子(独立解释方差为4.54%,P<0.001)。进一步应用多元统计分析,建立了45个湖泊的表层沉积物硅藻与水体TP的转换函数。采用偏最小二乘加权平均回归(WA-PLS)方法建立的转换函数模型中,组分2的预测能力最强(R2_jack=0.465,RMSEP=0.396)。进一步结合星云湖沉积物硅藻群落的演替序列,定量重建了近百年来水体TP值的变化历史。重建结果与多年监测数据具有显著的一致性(P<0.001,R2=0.79,n=13),零模型检验进一步表明了水体TP浓度是驱动硅藻长期演替的显著因子。历史重建结果显示,在星云湖富营养化前的历史时期(约1950年前)水体TP的背景浓度约为 12.8~29.3 μg/L,可作为该污染湖泊开展环境修复的营养水平修复目标。研究表明,基于生物群落结构的湖泊营养水平定量重建方法可为建立云南污染湖泊的环境修复目标提供重要的分析手段。 |
| 关键词: 表层沉积物 硅藻 转换函数 营养水平 定量重建 星云湖 |
| DOI：10.18307/2023.0105 |
| 分类号: |
| 基金项目:国家自然科学基金项目(42171072)、云南省科技计划项目(202203AC100002-02)、云南省院士工作站项目(202005AF150005)、国家重点研发计划项目(2017YFA0605202)和异龙湖高原浅水湖泊云南省野外科学观测研究站项目联合资助。 |
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| Evaluation of the quantitative relationships between diatom communities and total phosphorus (TP) in 45 lakes and their applications for TP reconstruction in Yunnan, Southwest China |
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Chen Xiaolin1,2, Chen Guangjie1, Liu Yuanyuan1, Li Rui1
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1.Yunnan Key Laboratory of Plateau Geographical Processes and Environmental Change, Faculty of Geography, Yunnan Normal University, Kunming 650500, P. R. China;2.College of Geography and Land Engineering, Yuxi Normal University, Yuxi 653100, P. R. China
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| Abstract: |
| With the expansion of the drainage basin development since the middle of the 20th Century, catchment export and lake-water enrichment of nutrients have led to a continuous process of lake eutrophication in Yunnan, which has significantly impacted the structuring of biological communities and health of the lake ecosystems. On the regional scale, the time span of modern water quality monitoring records is generally short (i.e.<20 years); this has prevented a reliable evaluation of pre-disturbance level of nutrient status for the lake ecological restoration. The application of paleolimnological methods to establish diatom-nutrient quantitative model can provide important information for water quality evaluation and ecological restoration of the polluted lakes. In this study, 45 lakes in Southwest Yunnan were selected for analyzing the surface sediment diatom communities, and in combination with the water monitoring data, the key environmental gradient was then identified in driving diatom assemblages. We further identified that the lake-water TP was a significant environmental factor responsible for the spatial variations of diatom assemblages (a variance of 4.54% explained independently, P<0.01). Furthermore, the transfer function between the surface sediment diatoms and TP in 45 lakes was established through multivariate statistical analyses. Among the transfer function models established by Weighted Average Partial Least Squares regression (WA-PLS), the component 2 has the strongest prediction ability (R2jack=0.465, RMSEP=0.396). Combining with the sediment diatom sequence of Lake Xingyun, lake-water TP values were reconstructed with this WA-PLS-2 model for the past 100 years. The null model results confirmed that lake-water TP played a significant role in driving diatom variations, and the predicted TPs show a significant correlation with the observed TPs (R2=0.79, P<0.001, n=13). The reconstruction results show that the background concentrations of TP, prior to the period of eutrophication (before 1950 AD), varied in the range of 12.8-29.3 μg/L for Lake Xingyun, which can be used as the restoration target of nutrient levels for lake restoration. This study shows that the quantitative reconstruction method of lake-water nutrient levels based on biological communities can provide reliable technical support for the construction of environmental restoration target for eutrophic lakes in Yunnan. |
| Key words: Surface sediments diatoms transfer function trophic level quantitative reconstruction Lake Xingyun |
