Response of temperate lakes to drought: a paleolimnological perspective on the landscape position concept using diatom-based reconstructions
Response of temperate lakes to drought: a paleolimnological perspective on the landscape position concept using diatom-based reconstructions
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温带湖泊对干旱的响应：利用基于硅藻的重建对景观位置概念的古湖泊学视角
DOI：
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发表时间：
2016
影响因子：
2.1
通讯作者：
S. Hotchkiss
中科院分区：
文献类型：
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作者：
Courtney R. Wigdahl‐Perry;J. Saros;J. Schmitz;Randy Calcote;J. Rusak;Dennis S. Anderson;S. Hotchkiss
湖泊在景观中的水文位置可以影响许多湖泊的化学，物理和生物特征，以及湖泊如何应对环境变化。我们对韦伯斯特等人（2000）提出的景观位置和湖泊对气候变化响应的模型进行了古湖沼学测试。为了研究硅藻群落如何应对干旱相对景观位置，我们研究了沉积硅藻剖面延伸到二十世纪世纪从高地网站（水晶湖）和低地网站（Allequash湖）在北方高地地区的中北部威斯康星州（美国）。为了探索硅藻群落在每个站点的变化，我们开发了一个校准集和传递函数从48个湖泊在威斯康星州的北方高地湖区。我们进一步确定了两个目标湖泊中的浮游生物：底栖生物的比例，开发了湖泊水位模型，并调查了浮游生物：底栖硅藻比例对过去世纪气候变化的敏感性。在高地湖泊，硅藻群落通过干旱引起的湖泊水位变化间接地对气候做出反应，这导致了南极和底栖生境的变化。硅藻对栖息地可用性变化的这种反应为追踪高地湖泊的气候变化提供了一种替代方法，尽管必须仔细考虑水深的影响及其与各个地点的湖平面变化和栖息地分区的关系。在低地湖泊中，硅藻群落的变化与温度（可能还有湖水化学）和物理变化有关。这些结果与韦伯斯特等人（2000年）的模型一致，化学变化发生在低地系统中，而高地系统中的化学反应很小。然而，这里提出的沉积物记录中的生物变化提供了更多的洞察湖泊对气候变化的响应是如何由景观位置塑造的，有助于更清楚地了解干旱条件下生态系统结构和功能的潜在变化。
The hydrological position of a lake within the landscape can affect a number of lake chemical, physical, and biological features, as well as how lakes respond to environmental change. We present a paleolimnological test of the model for landscape position and lake response to climate change proposed by Webster et al. (2000). To investigate how diatom communities have responded to drought relative to landscape position, we examined sedimentary diatom profiles extending through the twentieth century from an upland site (Crystal Lake) and a lowland site (Allequash Lake) in the Northern Highlands region of north-central Wisconsin (USA). To explore changes in diatom communities at each site, we developed a calibration set and transfer functions from 48 lakes in Wisconsin’s Northern Highland Lake District. We further determined planktic:benthic ratios in the two target lakes, developed lake level models, and investigated the sensitivity of planktic:benthic diatom ratios to climatic variability over the past century. In the upland lake, diatom communities responded indirectly to climate via drought-induced changes in lake level, which resulted in shifts in planktic versus benthic habitat availability. This response of diatoms to changes in habitat availability provides an alternative approach for tracking climate change in upland lakes, though careful consideration must be given to the effect of the bathymetry and its relationship to lake level change and habitat zonation at individual sites. In the lowland lake, changes in diatom communities were related to temperature (and possibly lakewater chemistry) and physical changes secondarily. These results are consistent with the model by Webster et al. (2000), with chemical changes occurring in the lowland system and little chemical response in the upland system. However, the biological changes in sediment records presented here provide additional insight into how lake response to climatic change is shaped by landscape position, contributing to a clearer understanding of potential changes in ecosystem structure and function during drought conditions.