Temperature sensitivity of soil enzymes along an elevation gradient in the Peruvian Andes
Temperature sensitivity of soil enzymes along an elevation gradient in the Peruvian Andes
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DOI：
10.1007/s10533-015-0176-2
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发表时间：
2016-02
期刊：
影响因子：
4
通讯作者：
A. Nottingham;Benjamin L Turner;J. Whitaker;N. Ostle;R. Bardgett;N. McNamara;N. Salinas;P. Meir
中科院分区：
文献类型：
--
作者：
A. Nottingham;Benjamin L Turner;J. Whitaker;N. Ostle;R. Bardgett;N. McNamara;N. Salinas;P. Meir
土壤酶是有机质解聚的催化剂，对生态系统碳循环至关重要。更好地了解酶对温度的敏感性将有助于更好地预测气候变化对土壤碳储量的影响。这些影响在热带山地森林中可能特别大，因为那里含有大量的土壤碳。我们确定了一系列水解和氧化酶的温度敏感性（Q10）参与有机质循环从土壤沿着1900米的海拔梯度（10 °C的年平均温度梯度）的热带山地森林在秘鲁安第斯山脉。我们研究了所选酶的活性（Vmax）是否：（i）表现出随海拔和/或土壤性质而变化的aQ 10;（ii）在酶之间变化，并根据C-降解酶的目标底物的复杂性。β-葡萄糖苷酶和β-木聚糖酶的Vmax的Q10随海拔的升高和年平均气温的降低而增大。对于所有其他酶，包括纤维二糖水解酶、N-乙酰β-氨基葡萄糖苷酶和磷酸单酯酶，Vmax的Q10不随海拔呈线性变化。降解更复杂的C化合物的水解酶具有更高的Vmax的Q10，但这种模式不适用于氧化酶，因为酚氧化酶具有这里研究的所有酶中最低的Q10值。我们的研究结果表明，不同酶类的温度敏感性的区域差异可能会影响未来气候变暖下的陆地碳循环。
Soil enzymes are catalysts of organic matter depolymerisation, which is of critical importance for ecosystem carbon (C) cycling. Better understanding of the sensitivity of enzymes to temperature will enable improved predictions of climate change impacts on soil C stocks. These impacts may be especially large in tropical montane forests, which contain large amounts of soil C. We determined the temperature sensitivity (Q10) of a range of hydrolytic and oxidative enzymes involved in organic matter cycling from soils along a 1900 m elevation gradient (a 10 °C mean annual temperature gradient) of tropical montane forest in the Peruvian Andes. We investigated whether the activity (Vmax) of selected enzymes: (i) exhibited aQ10that varied with elevation and/or soil properties; and (ii) varied among enzymes and according to the complexity of the target substrate for C-degrading enzymes. TheQ10ofVmaxfor β-glucosidase and β-xylanase increased with increasing elevation and declining mean annual temperature. For all other enzymes, including cellobiohydrolase,N-acetyl β-glucosaminidase and phosphomonoesterase, theQ10ofVmaxdid not vary linearly with elevation. Hydrolytic enzymes that degrade more complex C compounds had a greaterQ10ofVmax, but this pattern did not apply to oxidative enzymes because phenol oxidase had the lowestQ10value of all enzymes studied here. Our findings suggest that regional differences in the temperature sensitivities of different enzyme classes may influence the terrestrial C cycle under future climate warming.