Mapping physiology: biophysical mechanisms define scales of climate change impacts
Mapping physiology: biophysical mechanisms define scales of climate change impacts
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DOI：
10.1093/conphys/coz028
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发表时间：
2019-08-13
影响因子：
2.7
通讯作者：
Helmuth, Brian
中科院分区：
文献类型：
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作者：
Choi, Francis;Gouhier, Tarik;Helmuth, Brian
岩石潮间带是一个高度动态和温度多变的生态系统，太阳辐射、气温和地形的综合影响可导致在退潮时的空中暴露期间，在厘米尺度上产生15摄氏度以上的差异。对于大多数潮间带生物来说，这种小气候中的小规模异质性可能会对生存和生理表现产生巨大影响。然而，环境异质性在确定对气候变化的生态反应方面的潜在生态重要性仍然知之甚少。我们提出了一个新的框架，用于生成相互作用的有机体之间的小气候异质性和热生理模式的空间显式模型。我们使用无人机摄影测量从马萨诸塞州的一个潮间带站点以2 x 2厘米的分辨率创建了一张地形图(数字高程模型)，然后将其输入到基于天视系数和太阳位置的入射太阳辐射模型中。这些数据又被用来驱动一个热量预算模型，该模型估计了一年(2017年)每小时的地表温度。然后，利用热性能曲线，将体温层转换为生物体的热性能层，创造出在空间和时间上都显示出明显的“微庇护”模式的“生理景观”。我们的框架显示了这些层之间的非线性相互作用如何导致对有机体表现和生存的预测，这与仅使用任何单个层(例如地形、温度)所做的预测不同。我们提出了一种新的度量方法来量化站点的“热粗糙度”(RqT，温度空间偏差的均方根)，该度量可以用来量化站点级别的温度和性能的时空变异性。这些方法有助于利用空间显式和基于频率的方法来探索微地形变异性在驱动生物体对环境变化的脆弱性方面的作用。
The rocky intertidal zone is a highly dynamic and thermally variable ecosystem, where the combined influences of solar radiation, air temperature and topography can lead to differences greater than 15 degrees C over the scale of centimetres during aerial exposure at low tide. For most intertidal organisms this small-scale heterogeneity in microclimates can have enormous influences on survival and physiological performance. However, the potential ecological importance of environmental heterogeneity in determining ecological responses to climate change remains poorly understood. We present a novel framework for generating spatially explicit models of microclimate heterogeneity and patterns of thermal physiology among interacting organisms. We used drone photogrammetry to create a topographic map (digital elevation model) at a resolution of 2 x 2 cm from an intertidal site in Massachusetts, which was then fed into to a model of incident solar radiation based on sky view factor and solar position. These data were in turn used to drive a heat budget model that estimated hourly surface temperatures over the course of a year (2017). Body temperature layers were then converted to thermal performance layers for organisms, using thermal performance curves, creating 'physiological landscapes' that display spatially and temporally explicit patterns of 'microrefugia'. Our framework shows how non-linear interactions between these layers lead to predictions about organismal performance and survivorship that are distinct from those made using any individual layer (e.g. topography, temperature) alone. We propose a new metric for quantifying the 'thermal roughness' of a site (RqT, the root mean square of spatial deviations in temperature), which can be used to quantify spatial and temporal variability in temperature and performance at the site level. These methods facilitate an exploration of the role of micro-topographic variability in driving organismal vulnerability to environmental change using both spatially explicit and frequency-based approaches.