The land-use legacy effect: Towards a mechanistic understanding of time-lagged water quality responses to land use/cover.
The land-use legacy effect: Towards a mechanistic understanding of time-lagged water quality responses to land use/cover.
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DOI：
10.1016/j.scitotenv.2016.11.158
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发表时间：
2017-02
期刊：
影响因子：
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通讯作者：
S. L. Martin;D. Hayes;A. Kendall;D. Hyndman
中科院分区：
文献类型：
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作者：
S. L. Martin;D. Hayes;A. Kendall;D. Hyndman
许多研究将土地利用/土地覆盖（LULC）与水生生态系统响应联系起来，但只有少数研究在分析中包括了变化的LULC的动态。在这项研究中，我们明确地认识到不断变化的LULC通过连接机械地下水流和旅行时间模型的历史时间序列的LULC，创建一个土地利用的遗产地图。然后，我们说明了传统地图的效用，探索动态LULC和湖水化学之间的关系。我们测试了两个主要概念的机制连接LULC和湖泊水化学：地下水路径是一个重要的机制驱动的遗产效应;和，LULC在多个空间尺度上是更密切相关的湖泊化学比LULC在一个单一的空间尺度。我们应用统计模型，以12个水化学变量，从营养物质相对保守的离子，以更好地了解土壤地球化学反应性和溶解度之间的连接LULC和水生生态系统响应的作用。我们的研究说明了不同的地区如何有很长的地下水通道，这些通道代表了与今天在景观上看到的不同的LULC。这些地下水通道延迟了营养物质和其他水质成分的到达，从而造成了最终到达地表水的历史土地使用的遗产。我们发现：1）几个水化学变量最适合传统LULC，而其他变量与当前LULC有更强的联系，2）单一空间尺度的LULC分析对大多数变量的表现较差。我们的时间和空间尺度的新组合是最适合大多数变量的整体模型，包括SRP，该模型解释了54%的变异。我们表明，重要的是要明确考虑到时间和空间的背景下，连接LULC生态系统的响应。
Numerous studies have linked land use/land cover (LULC) to aquatic ecosystem responses, however only a few have included the dynamics of changing LULC in their analysis. In this study, we explicitly recognize changing LULC by linking mechanistic groundwater flow and travel time models to a historical time series of LULC, creating a land-use legacy map. We then illustrate the utility of legacy maps to explore relationships between dynamic LULC and lake water chemistry. We tested two main concepts about mechanisms linking LULC and lake water chemistry: groundwater pathways are an important mechanism driving legacy effects; and, LULC over multiple spatial scales is more closely related to lake chemistry than LULC over a single spatial scale. We applied statistical models to twelve water chemistry variables, ranging from nutrients to relatively conservative ions, to better understand the roles of biogeochemical reactivity and solubility on connections between LULC and aquatic ecosystem response. Our study illustrates how different areas can have long groundwater pathways that represent different LULC than what can be seen on the landscape today. These groundwater pathways delay the arrival of nutrients and other water quality constituents, thus creating a legacy of historic land uses that eventually reaches surface water. We find that: 1) several water chemistry variables are best fit by legacy LULC while others have a stronger link to current LULC, and 2) single spatial scales of LULC analysis performed worse for most variables. Our novel combination of temporal and spatial scales was the best overall model fit for most variables, including SRP where this model explained 54% of the variation. We show that it is important to explicitly account for temporal and spatial context when linking LULC to ecosystem response.