Soil carbon losses to the atmosphere, via soil heterotrophic respiration, are expected to increase in response to global warming, resulting in a positive carbon-climate feedback. Despite the well-known suite of abiotic and biotic factors controlling soil respiration, much less is known about how the magnitude of soil respiration responses to temperature changes over soil development and across contrasting soil properties. Here we investigated the role of soil development stage and soil properties in driving the responses of soil heterotrophic respiration to temperature. We incubated soils from eight chronosequences ranging in soil age from hundreds to million years, and encompassing a wide range of vegetation types, climatic conditions and chronosequences origins, at three assay temperatures (5 °C, 15 °C and 25 °C). We found a consistent positive effect of assay temperature on soil respiration rates across the eight chronosequences evaluated. However, chronosequences parent materials (sedimentary/sand dunes or volcanic) and soil properties (pH, phosphorus content and microbial biomass) determined the magnitude of this temperature effect. Finally, we observed a positive effect of soil development stage on soil respiration across chronosequences that did not alter the magnitude of assay temperature effects. Our work reveals that key soil properties alter the magnitude of the positive effect of temperature on soil respiration found across ecosystem types and soil development stages. This information is essential to better understand the magnitude of the carbon-climate feedback and thus to establish accurate greenhouse gas emission targets.

通过土壤异养呼吸，土壤向大气中的碳损失预计会随着全球变暖而增加，从而产生积极的碳气候反馈。尽管众所周知的一系列非生物和生物因子控制着土壤呼吸，但是人们对土壤呼吸对温度在整个土壤发育过程中以及在相反的土壤特性中变化的反应程度的了解却鲜为人知。在这里，我们研究了土壤发育阶段和土壤性质在驱动土壤异养呼吸对温度的响应中的作用。我们在三个测定温度（5°C，15°C和25°C）下，对八个年龄序列的土壤进行了温育，这些年龄序列的土壤年龄从几百年到一百万年不等，涵盖了广泛的植被类型，气候条件和时间序列起源。我们发现，在评估的八个时间序列中，测定温度对土壤呼吸速率具有一致的积极影响。但是，按时间顺序排列的母体物质（沉积/沙丘或火山）和土壤性质（pH，磷含量和微生物生物量）决定了这种温度影响的大小。最后，我们观察到土壤发育阶段对不同时序土壤呼吸的积极影响，但并未改变测定温度影响的幅度。我们的工作表明，关键的土壤性质会改变温度对生态系统类型和土壤发育阶段发现的土壤呼吸的积极影响的大小。此信息对于更好地了解碳气候反馈的幅度，从而建立准确的温室气体排放目标至关重要。