Regional variability among nonlinear chlorophyll-phosphorus relationships in lakes
Regional variability among nonlinear chlorophyll-phosphorus relationships in lakes
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DOI：
10.4319/lo.2014.59.5.1691
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发表时间：
2014-09-01
影响因子：
4.5
通讯作者：
Downing, John A.
中科院分区：
文献类型：
--
作者：
Filstrup, Christopher T.;Wagner, Tyler;Downing, John A.
在湖泊中，叶绿素a(Chla)和总磷(TP)之间的关系是反映生态系统功能的多个方面的基本关系，也被用于内陆水域的调节和管理。这种关系的确切形式对它的意义和使用有重大影响。我们收集了一个空间广泛的数据集，以检验非线性模型是否比传统的对数-线性模型更适合于Chl a a TP关系，是否存在关系形式的地区差异，如果是，哪些地区因素与这些差异有关。通过对两个不同的非线性模型和一个对数线性模型的拟合和比较，对35个生态区的2105个温带湖泊的数据进行了分析。两种非线性模型比对数线性模型对数据的拟合效果更好。此外，最佳拟合模型的参数因区域不同而不同：最大和最低Chl a渐近线分别与区域草地利用率正相关和负相关，叶绿素随TP增加的速率与区域湿地覆盖率负相关。牧场较多地区的湖泊在高TP浓度时最大叶绿素浓度较高，而在低TP浓度时最低叶绿素浓度较低。湿地覆盖度较低地区的湖泊表现出比湿地丰富地区更陡峭的Chla-TP关系。对Chl a-TP关系的解释依赖于区域差异，基于单一关系的理论和管理可能是不准确的。
The relationship between chlorophyll a (Chl a) and total phosphorus (TP) is a fundamental relationship in lakes that reflects multiple aspects of ecosystem function and is also used in the regulation and management of inland waters. The exact form of this relationship has substantial implications on its meaning and its use. We assembled a spatially extensive data set to examine whether nonlinear models are a better fit for Chl a TP relationships than traditional log-linear models, whether there were regional differences in the form of the relationships, and, if so, which regional factors were related to these differences. We analyzed a data set from 2105 temperate lakes across 35 ecoregions by fitting and comparing two different nonlinear models and one log-linear model. The two nonlinear models fit the data better than the log-linear model. In addition, the parameters for the best-fitting model varied among regions: the maximum and lower Chl a asymptotes were positively and negatively related to percent regional pasture land use, respectively, and the rate at which chlorophyll increased with TP was negatively related to percent regional wetland cover. Lakes in regions with more pasture fields had higher maximum chlorophyll concentrations at high TP concentrations but lower minimum chlorophyll concentrations at low TP concentrations. Lakes in regions with less wetland cover showed a steeper Chl a-TP relationship than wetland-rich regions. Interpretation of Chl a-TP relationships depends on regional differences, and theory and management based on a monolithic relationship may be inaccurate.