2017年5月3日，董云伟教授课题组与美国东北大学、斯坦福大学和香港大学研究者合作在Proceedings of the Royal Society B: Biological Sciences期刊发表题为"Untangling the roles of microclimate, behavior and physiological polymorphism in governing vulnerability of intertidal snails to heat stress"的研究论文，阐述了小尺度的环境和生理过程的多样性对于气候变化研究的意义。
生物对于全球气候变化下极端气候条件的响应是当今的研究热点之一。然而针对这个问题，现多采用全球尺度或生物地理尺度模型进行研究，而忽略了小尺度生理和生态过程的生态学意义。本研究针对“小尺度的生态和生理过程是否会影响气候变化预测的准确性”在潮间带腹足类进行了较为系统的研究。研究发现，小尺度的生态和生理过程的多样性可以影响模型预测的准确性，提出在未来气候变化研究中需要重视小尺度生态过程的重要性。
本研究选取中国沿岸纬度跨度达11.5° 的8个地点，以3种常见腹足类（中华滨螺Littoraria sinensis，短滨螺Littorina brevicula，齿纹蜒螺Nerita yoldii）为研究对象，整合生理学和生物物理学模型，以心率作为热耐受指标，绘制心脏性能曲线，计算致死性温度耐受上限（Flat Line Temperature, FLT）和亚致死性温度耐受上限（Arrhenius Breakpoint Temperature, ABT），分析生物热耐受能力及其在不同地理尺度上的差异。同时通过热量平衡模型（Heat Budget Model），计算不同微环境下3种螺类体温，计算热应激安全范围（Thermal Safety Margin, TSM），分析生物受热胁迫的情况。对体温进行自相关分析，推测生物对于高温事件的预测及躲避能力。综合分析，探究微环境与生理多态性在潮间带腹足类抵御热胁迫中的作用，并对中国沿岸潮间带腹足类热胁迫情况进行研究。
齿纹蜒螺
潮间带生态系统具有复杂的微生境，综合考虑小尺度的生态和生理过程的异质性在评估全球气候变化的生态效应的研究中具有重要意义。本研究表明，小尺度温度环境和生理适应能力的差异性对于种群适合度具有重要影响。阴面微环境为生物提供了良好的避难所以躲避高温。然而在温度胁迫最为严重的地区，生物对于高温事件的预测能力较低，影响行为调节的效果。生物的生理耐受性具有高度的差异性，部分个体具有极高的耐受温度上限，能够在极端高温时间中存活，保证整个种群的存活率。综合环境温度和生理适应能力结果，对中国沿岸潮间带生物对气温升高的敏感性进行了预测。结果表明，在全球气候变化的大背景下，气温持续升高，扬子大三角洲沿岸将会是我国温带及亚热带沿海地区最易受扰动的区域。
Figure 1. Relationship between cardiac performance (ABT, FLT) and TSM. (a) Heart rate increases with temperature until the Arrhenius Breakpoint Temperature (ABT) is reached and then decreases rapidly to zero (black circles and the red curve following left y-axis). ABT was calculated by linear regression (blue lines) using data on Arrhenius plots (gray circles following the right y-axis) that lay either above or below the temperature at which the highest heart rate occurred. The temperature at which these two lines intersected was taken as the ABT. FLT is the temperature where heart beat ceases. TSM is defined as the difference between an organism’s critical thermal maximum (ABT (nonlethal) or FLT (lethal)) and the highest body temperature that an organism is likely to experience in nature (TSMABT = ABT – Tbmax, TSMFLT = FLT - Tbmax). Due to the physiological polymorphism and microhabitat heterogeneity, TSM varies among (b) individuals and (c) microhabitats.
Figure 2. High inter-individual, inter-population and interspecific variability in cardiac performance curves. (a) Variation within a population: dashed lines depict individual heart rates and the solid line depicts the curve for all individuals of L. sinensis from the Xiamen population (n = 10). (b) Variation among populations: dashed lines depict heart rate curves generated for each population and the solid line depicts the curve for all individuals of L. sinensis from all populations (n = 70). (c) Interspecific comparisons: the solid, dashed and dotted lines depict the heart rate curves of L. sinensis, L. brevicula and N. yoldii, respectively.
Figure 3. Phase diagrams of heat-tolerance limits and maximum operative temperatures in sun-exposed (a, c) and shaded habitats (b, d). The white region shows where species have a physiological thermal-safety margin for ABT and FLT; the shaded region shows where species are threatened by temperatures above either ABT (c, d) or FLT (a, b) thermal stress.
Figure 4. Thermal safety margin (TSM) of three gastropods with latitude. Solid lines show linear regressions for TSM with latitude and dotted lines show 95% confidence intervals. TSM was calculated for the FLT (a, b) and the ABT (c, d) in sun-exposed (a, c) and shaded habitats (b, d).
该研究结果于2017年5月发表于Proceedings of the Royal Society B: Biological Sciences（英国皇家学会会刊B辑，近五年影响因子5.366）。
Citation: Dong Y-wei, Li X-xu, Choi FMP, Williams GA, Somero GN, Helmuth B. 2017 Untangling the roles of microclimate, behaviour and physiological polymorphism in governing vulnerability of intertidal snails to heat stress. Proc. R. Soc. B 284: 20162367. http://dx.doi.org/10.1098/rspb.2016.2367
全文链接：http://rspb.royalsocietypublishing.org/content/284/1854/20162367
