Halsey L G, Matthews P G D, Rezende E L, Chauvaud L, Robson A A
Department of Life Sciences, Centre for Research in Ecology, University of Roehampton, Holybourne Avenue, London, SW15 4JD, UK,
Oecologia. 2015 Apr;177(4):1117-29. doi: 10.1007/s00442-014-3190-5. Epub 2015 Jan 10.
The rate of change in resting metabolic rate (RMR) as a result of a temperature increase of 10 °C is termed the temperature coefficient (Q10), which is often used to predict how an organism's total MR will change with temperature. However, this method neglects a potentially key component of MR; changes in activity level (and thus activity MR; AMR) with temperature may significantly alter the relationship between MR and temperature. The present study seeks to describe how thermal effects on total MR estimated from RMR-temperature measurements can be misleading when the contribution of activity to total MR is neglected. A simple conceptual framework illustrates that since the relationship between activity levels and temperature can be different to the relationship between RMR and temperature, a consistent relationship between RMR and total MR cannot be assumed. Thus the thermal effect on total MR can be considerably different to the thermal effect on RMR. Simultaneously measured MR and activity from three ectotherm species with differing behavioural and physiological ecologies were used to empirically examine how changes in temperature drive changes in RMR, activity level, AMR and the Q10 of MR. These species exhibited varied activity- and MR-temperature relationships, underlining the difficulty in predicting thermal influences on activity levels and total MR. These data support a model showing that thermal effects on total MR will deviate from predictions based solely on RMR; this deviation will depend upon the difference in Q10 between AMR and RMR, and the relative contribution of AMR to total MR. To develop mechanistic, predictive models for species' metabolic responses to temperature changes, empirical information about the relationships between activity levels, MR and temperature, such as reported here, is required. This will supersede predictions based on RMR alone.
静息代谢率（RMR）因温度升高10°C而产生的变化率被称为温度系数（Q10），它常被用于预测生物体的总代谢率（MR）将如何随温度变化。然而，这种方法忽略了代谢率的一个潜在关键组成部分；活动水平（以及由此产生的活动代谢率；AMR）随温度的变化可能会显著改变代谢率与温度之间的关系。本研究旨在描述当忽略活动对总代谢率的贡献时，根据RMR-温度测量估算的热效应如何误导对总代谢率的判断。一个简单的概念框架表明，由于活动水平与温度之间的关系可能与RMR和温度之间的关系不同，因此不能假定RMR与总代谢率之间存在一致的关系。因此，热对总代谢率的影响可能与热对RMR的影响有很大差异。同时测量了三种具有不同行为和生理生态的变温动物的代谢率和活动，以实证研究温度变化如何驱动RMR、活动水平、AMR以及代谢率的Q10的变化。这些物种表现出不同的活动-代谢率与温度的关系，凸显了预测热对活动水平和总代谢率影响的困难。这些数据支持了一个模型，该模型表明热对总代谢率的影响将偏离仅基于RMR的预测；这种偏差将取决于AMR和RMR的Q10之间的差异，以及AMR对总代谢率的相对贡献。为了建立物种对温度变化代谢反应的机制性预测模型，需要有关活动水平、代谢率和温度之间关系的实证信息，如此处报告的信息。这将取代仅基于RMR的预测。
