土壤呼吸速率的温度敏感性由微生物社区反应增强
Kristiina Karhu1, Marc D Auffret2, Jennifer A J Dungait3
11] Geography, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK [2] Department of Forest Sciences, University of Helsinki, 00014 Helsinki, Finland.
Nature
|September 5, 2014
概括
土壤微生物加速二氧化碳的释放随着变暖,特别是在寒冷的地区. 这种微生物反应放大了土壤呼吸的温度敏感性,可能释放的碳比预期的更多.
科学领域:
- 土壤科学 土壤科学
- 微生物学 微生物学
- 气候变化研究 气候变化研究
背景情况:
- 土壤是重要的碳储存库,储存的碳是植物生物质的四倍.
- 土壤微生物的呼吸每年会向大气中释放大量的二氧化碳 (CO2).
- 当前的地球系统模型包括土壤呼吸的温度灵敏度,预测影响气候变化的积极反循环.
研究的目的:
- 研究土壤微生物社区的反应如何影响各种生态系统的土壤呼吸的温度敏感性.
- 为了确定微生物社区层面的反应是否会放大或减轻由变暖引起的土壤碳损失.
- 评估土壤碳储存的脆弱性,特别是在寒冷的地区,气候变暖.
主要方法:
- 收集了来自各种生态系统的土壤,覆盖了从北极到亚马逊的气候梯度.
- 研究了微生物社区对温度变化的反应.
- 在中长期 (90天) 期间测量了土壤呼吸的温度灵敏度.
主要成果:
- 微生物社区的反应更频繁地增强而不是降低了土壤呼吸的温度敏感性.
- 在碳比较高的土壤和寒冷气候的土壤中观察到最强的增强反应.
- 90天后,微生物反应在高度土壤中增加了呼吸的温度灵敏度的1.4倍,与瞬间反应相比.
结论:
- 土壤微生物社区的反应通常会放大土壤呼吸的温度敏感性.
- 北极和北极土壤的碳储量可能比目前的模型预测更容易受到气候变暖的影响.
- 了解微生物反应对于准确预测土壤碳的气候变化反来说至关重要.
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