Effects of soil iron and aluminium on organic carbon in Pinus massoniana forests in the Three Gorges Reservoir area
To comprehensively understand the impact of various forms of iron(Fe)and aluminium(Al)minerals on soil organic carbon(SOC)stabilization,this study was conducted in the Pinus massoniana forest with typical soil textures in the Three Gorges Reservoir area.The contents of Fe and Al minerals in the crystalline minerals(DH),short-range order minerals(HH),and organo-metal complexes(PP),along with their associated organic carbon,were determined using a selective dissolution extraction method.The interrelationship between different forms of Fe,Al minerals,and their associated organic carbon with soil organic carbon was investigated through correlation analysis and multiple regression analysis.Key findings revealed:(1)varied Fe,Al mineral contents ranked DH＞PP＞HH,exhibiting a noticeable upward trend with increased clay content;(2)the organic carbon content extracted with DH,PP,and HH were(6.11±0.35)mg/g,(6.25±0.46)mg/g,and(1.14±0.06)mg/g,constituting approximately(32.06％±1.95％),(32.61％±2.33％),and(5.95％±0.33％)of SOC,respectively;(3)the carbon-to-metal(C∶Fe+Al)molar ratio indicated PP＞DH≈HH,suggesting a transition in the mineral-organic carbon interaction from co-precipitation and chelation toward adsorption with increased crystallinity;(4)extracted carbon content exhibited a positive correlation with the corresponding extracted metal(Fe+Al)(P＜0.05),with Fe and Al minerals explaining 74.65％of the SOC variability as the primary explanatory variables.In summary,the interplay between organic carbon and Fe,Al minerals significantly influences SOC stabilization and storage in the soil of Pinus massoniana forests in the Three Gorges Reservoir area.Crystalline Fe,Al minerals,and organo-mineral complexes emerged as pivotal factors driving this phenomenon.
vegetation restorationPinus massoniana forestsoilorganic carboniron and aluminium mineralsstabilization mechanism
万方数据
维普
