森林砍伐后的土壤C动态,以及在潮湿温带地区耕地转化为草原后的耕地转化
Agustín Merino1, Beatriz Omil1, Verónica Piñeiro2
1Department of Applied Physics, University of Santiago de Compostela, 27002 Lugo, Spain; Elemental Analysis RIAIDT, University of Santiago de Compostela, 27002 Lugo, Spain; Institute of Ecology, National Autonomous University of Mexico, Mexico City 04510, Mexico; Soil Science and Chemistry Department, University of Santiago de Compostela, 27002 Lugo, Spain.
The Science of the total environment
|July 26, 2023
概括
土地利用变化对土壤有机碳 (SOC) 储量产生重大影响. 将耕地转化为草原可以恢复土壤碳,主要是矿物相关有机物 (MAOM),强调植物土壤管理对土壤健康的重要性.
科学领域:
- 土壤科学 土壤科学
- 环境科学 环境科学
- 农业学是一种农业学.
背景情况:
- 土地利用和植物土壤管理是土壤有机碳 (SOC) 动态和土壤性质的关键驱动因素.
- 了解改变土壤有机物 (SOM) 的机制对于可持续的土地管理和气候变化缓解至关重要.
- 之前的研究表明,在森林砍伐和密集种植后,SOC的损失很大.
研究的目的:
- 研究土地利用和植物土壤管理影响土壤有机物 (SOM) 动态和库存的主要机制.
- 评估在土地利用过渡期间不同有机物 (OM) 区间的有机碳池和生物化学质量的变化.
- 评估将耕地转化为草原的有效性,以便在45年的时间序列中补充SOM.
主要方法:
- 表面土壤的物理分化,以分离自由颗粒有机物 (POM) 和矿物相关有机物 (MAOM).
- 使用13C NMR光谱和热分析 (DSC/TG) 进行SOM质量的表征.
- 通过异热微热度测量监测微生物活动.
主要成果:
- 森林砍伐和密集种植导致了80%的地表土壤碳损失,POM几乎完全耗尽,MAOM的损失显著 (> 40%).
- 由于土壤特异性表面积较低,以及其有机化合物的不稳定性,MAOM的损失被归因于此.
- 在45年内转化为草原,恢复了68%的丢失的土壤碳,主要是MAOM,以每年1.25Mg C ha-1的速度.
结论:
- 长期的SOM持久性取决于有机化合物对矿物表面的吸附强度及其生物化学性质.
- 有效的植物-土壤管理实践促进MAOM补充,作为碳储存和质量的关键活跃池.
- 这些发现证实了土壤碳分量的因土地利用和管理而变化的理论,强调了MAOM在土壤碳捕获中的作用.
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