土壤变暖和碳循环对气候系统的反
J M Melillo1, P A Steudler, J D Aber
1The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA. jmelillo@mbl.edu
概括
森林中的土壤变暖会导致由于有限的土壤碳排放而导致小的,暂时的二氧化碳释放. 然而,增加的可用性可能会促进植物生长,抵消土壤碳损失,并挑战气候模型.
科学领域:
- 森林生态森林生态学
- 土壤科学 土壤科学
- 气候变化研究研究 气候变化研究
背景情况:
- 土壤碳和循环对于森林生态系统和全球气候至关重要.
- 了解温度上升对这些周期的影响对于准确的气候建模至关重要.
研究的目的:
- 调查土壤变暖对中度硬木森林中碳和气循环的长期影响.
- 评估这些变化对气候系统的影响.
主要方法:
- 一个长达十年的土壤变暖实验是在中度硬木森林中进行的.
- 测量重点是土壤有机物衰变,二氧化碳流动和矿物的可用性.
主要成果:
- 土壤变暖导致土壤有机物分解和二氧化碳排放的加速,但效应很小且短暂.
- 不稳定土壤碳池的有限大小限制了变暖反应.
- 变暖增加了植物对矿物的可用性.
结论:
- 由于有限的可变碳,变暖对土壤碳释放的影响不如预期那么重要.
- 增加的可用性可以刺激植物生长,这可能导致生物质中碳捕获的增加.
- 这些发现挑战了气候模型的预测,这些气候模型预测由于森林变暖而导致的长期土壤碳损失相当大.
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