Nonlinear averaging of thermal experience predicts population growth rates in a thermally variable environment

As thermal regimes change worldwide, projections of future population and species persistence often require estimates of how population growth rates depend on temperature. These projections rarely account for how temporal variation in temperature can systematically modify growth rates relative to projections based on constant temperatures. Here,we tested the hypothesis that time-averaged population growth rates in fluctuating thermal environments differ from growth rates in constant conditions as a consequence of Jensen’s inequality, and that the thermal performance curves (TPCs) describing population growth in fluctuating environments can be predicted quantitatively based on TPCs generated in constant lab conditions. With experimental populations of the green alga Tetraselmis tetrahele, we show that nonlinear averaging techniques accurately predicted increased as well as decreased population growth rates influctuating thermal regimes relative to constant thermal regimes. We extrapolate...随着全球热环境动态发生改变，在预测未来种群与物种存续情况时，往往需要估算种群增长率对温度的依赖关系。现有这类预测极少考虑温度的时间变异会如何系统性地改变种群增长率，而这一点与基于恒定温度的预测存在差异。本研究验证了两项假说：其一，波动热环境下的时间平均种群增长率会因詹森不等式（Jensen's Inequality）与恒定条件下的增长率存在差异；其二，描述波动环境中种群增长的热性能曲线（TPCs），可通过实验室恒定条件下得到的TPCs进行定量预测。本研究以绿色藻类四鞭藻（Tetraselmis tetrahele）的实验种群为材料，结果表明，相较于恒定热环境，非线性平均技术可准确预测波动热环境下种群增长率的升高与降低。本研究进一步推演……