Will Invertebrates Require Increasingly Carbon-Rich Food in a Warming World?
Will Invertebrates Require Increasingly Carbon-Rich Food in a Warming World?
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DOI：
10.1086/694122
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发表时间：
2017-12-01
影响因子：
2.9
通讯作者：
Mayor, Daniel J.
中科院分区：
文献类型：
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作者：
Anderson, Thomas R.;Hessen, Dag O.;Mayor, Daniel J.
温度升高导致变温生物体的代谢和呼吸增加。我们假设，无脊椎动物消费者将因此需要在变暖的环境中越来越多的富碳饮食，因为增加的能量需求主要是使用富含碳的化合物，即碳水化合物和脂质。在这里，我们使用一个新的化学计量模型来测试这个假设，该模型以碳（C）和氮（N）为货币。模型预测并不支持这一假设，相反，无脊椎动物的营养需求，至少在食物质量方面表示为C：N比，可能会改变很少，如果在所有，在高温下。两个因素促成了这一结论。首先，无脊椎动物面临营养元素（如氮）的限制，默认情况下，其食物中有过量的C，可用于满足变暖环境中对能量的需求增加，而无需依赖额外的膳食C。其次，在高温下增加进食可以补偿新陈代谢的额外需求，以至于当新陈代谢和摄入量与温度相同时（具有相同的Q（10）），对膳食C和N的相对需求保持不变。我们的分析表明，未来气候驱动的自养生物量的C：N比的增加可能会加剧营养有限的无脊椎动物食草动物和它们的食物之间的化学计量不匹配，对生态系统中的C固存和营养循环产生重要影响。
Elevated temperature causes metabolism and respiration to increase in poikilothermic organisms. We hypothesized that invertebrate consumers will therefore require increasingly carbon-rich diets in a warming environment because the increased energetic demands are primarily met using compounds rich in carbon, that is, carbohydrates and lipids. Here, we test this hypothesis using a new stoichiometric model that has carbon (C) and nitrogen (N) as currencies. Model predictions did not support the hypothesis, indicating instead that the nutritional requirements of invertebrates, at least in terms of food quality expressed as C:N ratio, may change little, if at all, at elevated temperature. Two factors contribute to this conclusion. First, invertebrates facing limitation by nutrient elements such as N have, by default, excess C in their food that can be used to meet the increased demand for energy in a warming environment, without recourse to extra dietary C. Second, increased feeding at elevated temperature compensates for the extra demands of metabolism to the extent that, when metabolism and intake scale equally with temperature (have the same Q(10)), the relative requirement for dietary C and N remains unaltered. Our analysis demonstrates that future climate-driven increases in the C:N ratios of autotroph biomass will likely exacerbate the stoichiometric mismatch between nutrient-limited invertebrate grazers and their food, with important consequences for C sequestration and nutrient cycling in ecosystems.