欢迎点击上方名片关注！推送等相关事宜直接后台私信即可！农业梯田是分布最广泛的人类建造地貌类型之一。它们深刻重塑了土壤景观并影响碳循环，但其影响的程度及驱动因素仍存在较大不确定性。通过整合沿气候—地球化学梯度分布的14个排水良好梯田地貌单元的野外观测数据与综合数据分析，我们发现，梯田修筑后土壤有机碳（SOC）储量的变化受两种耦合的碳周转—地貌过程控制：一是侵蚀部位流失表层土壤碳的补偿过程，二是沉积部位埋藏SOC的稳定化过程。气候通过塑造土壤地球化学特性和植物生产力，进而调控梯田内SOC的补偿与稳定化，从而显著调节这些过程。因此，梯田对SOC储量的影响在湿润地区表现为持续正效应，而在干旱地区则呈现正负并存的混合结果。本研究构建了阐释排水良好梯田系统中SOC动态的理论框架，并为在全球农业梯田中实施有针对性的碳汇提升管理策略提供了科学依据。Fig. 1.Terrace-induced changes in SOC stock (∆SOC) and its relationships with climates and geomorphic positions.
Fig. 2. Large-scale validation of the pronounced role of climate in explaining divergent SOC responses to terracing.
Fig. 3. Effect of TPP and soil geochemistry on terracing-induced changes in SOC stock (∆SOC) estimated by PLS-SEM analysis.
Fig. 4. Terraced soils from 14 study sites along a climate gradient (n = 485) differ in their physiochemical properties relevant to SOC stabilization.
Fig. 5. The dominant SOC stabilization mechanism in terraced soils differed between humid versus arid regions.
Fig. 6. A mechanistic framework elucidating the geomorphic–biogeochemical processes regulating SOC stock changes in agricultural terraces across climate regions.
