在亚马逊热带雨林中,土壤循环穿过100年森林砍伐时间序列
Suwei Xu1, Chunhao Gu2, Jorge L M Rodrigues3,4
1Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Global change biology
|January 26, 2024
概括
亚马逊地区的森林砍伐显著改变了土壤 (P) 循环,增加了总P和有机P分量. 然而,在放弃牧场13年内,土壤P动态恢复到原始森林水平.
科学领域:
- 环境科学 环境科学
- 土壤科学 土壤科学
- 生物地质化学生物地质化学
背景情况:
- 热带雨林的砍伐是影响全球生物地球化学循环的重大土地利用变化.
- 土壤 (P) 循环对于生态系统的生产力至关重要,特别是在像亚马逊盆地这样的P有限地区.
研究的目的:
- 调查土地利用变化和持续时间对亚马逊盆地土壤动态的影响.
- 评估森林砍伐和随后的再造林如何影响土壤,水池和循环速度.
主要方法:
- 利用了原始森林转化为牧场的100年时间序列和13年的二级森林.
- 采用了顺序提取,PK边缘X射线吸收近边缘结构 (XANES) 谱学和土壤酸酶活性测试.
- 分析的土壤P池 (总,有机,无机) 和表面土壤 (0-10厘米深度) 中的酶动力学.
主要成果:
- 森林砍伐导致土壤中总P,总有机P (Po) 和总无机P (Pi) 的增加,非性Po的不成比例增加.
- 牧场年龄与增加的Pi分数相关,改变了酸酶动力学 (减少Km,增加Ka),以及Po可变性的变化.
- 土壤P池和循环率在放弃牧场13年内恢复到原始森林水平.
结论:
- 土壤P循环受到亚马逊森林砍伐的重大影响,P池和酶活性的长期变化.
- 再造林有效地恢复了土壤的P动态,但先前土地使用的持续时间 (牧场年龄) 对于理解恢复至关重要.
- 未来对亚马逊土地使用遗产的评估应考虑牧场持续时间和再造林年龄,以准确评估P循环.
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