植被恢复对油茶园梯壁土壤团聚体及赋存有机碳的影响

Impacts of Vegetation Restoration on Soil Aggregates and Soil Organic Carbon on the Terrace Wall of Camellia Oleifera Orchard

为研究梯壁稳定性与植被演替之间的关系,选取不同植被恢复年限(2年、5年、10年、30年)和不同植被演替阶段(裸地、苔藓、苔草、苔草灌)的梯壁为研究对象,采集表层(0—5 cm)和亚表层(5—20 cm)土壤样品,分析恢复年限和演替阶段对梯壁土壤团聚体及其赋存有机碳的影响。结果表明:土壤大团聚体(>0.25 mm)含量随演替阶段增加不断提高,相同演替阶段恢复年限越久大团聚体占比越高,30年苔草灌阶段大团聚体占比达91.63%;土壤平均重量直径(MWD)和几何平均直径(GMD)在0—5,5—20 cm土层均表现出随恢复时间增加逐渐增加趋势,30年土壤MWD和GMD分别为1.07~1.41,0.88~1.17 mm,在不同演替阶段表现为苔草灌>苔草>苔藓>裸地;土壤有机碳含量与大团聚体显著相关(r=0.83,p<0.001),表明植被演替与种植年限对于梯壁土壤固碳有积极影响。植被演替和植被恢复时长可以改善梯壁土壤结构,提高梯壁土壤团聚体稳定性和抗蚀性。研究结果可为优化梯田开发提供理论参考。

In order to study the relationship between terrace wall stability and vegetation succession,the terrace walls of different vegetation restoration years(2 years,5 years,10 years,and 30 years)and different vegetation restoration stages(bare land,moss,moss-grass,and moss-grass-shrub)were selected as the research objects,and soil samples of surface(0—5 cm)and subsurface(5—20 cm)were collected.The effects of restoration years and succession stages on soil aggregates and their organic carbon were analyzed.The results showed that the content of soil macroaggregates(>0.25 mm)increased with the increase of succession stage,and the proportion of macroaggregates was higher with the longer recovery years of the same succession stage,and the proportion of macroaggregates reached 91.63%in the 30 years moss-grass-scrub stage.Soil mean weight diameter(MWD)and geometric mean diameter(GMD)in 0—5 cm and 5—20 cm soil layers showed a gradual increasing trend with the increase of restoration time,with 30-year soil MWD and GMD ranging from 1.07 to 1.41 and 0.88 to 1.17 mm,respectively,and showing the characteristics of moss-grass-scrub>moss-grass>moss>bare land in different succession stages.Soil organic carbon content was significantly correlated with macroaggregates(r=0.83,p<0.001),indicating that vegetation succession and planting years had positive effects on soil carbon sequestration.Vegetation succession and vegetation recovery time can improve soil structure,stability and corrosion resistance of soil aggregates.The research results can provide theoretical reference for optimizing terrace development.