不同林龄工矿废弃地土壤团聚体稳定性与有机碳固持关联性OA

In order to explore the impact mechanism of vegetation restoration on soil aggregate structure and organic car-bon dynamics in industrial and mining wastelands,Pinus sylvestris var.mongolica plantations with different planting years(18,20,23,32 years)on industrial and mining wastelands in Qingling Forest Farm,Hegang City were studied.By combining field sampling and indoor analysis,the particle size distribution of soil aggregates,organic carbon mass fraction,and main soil chemical factors(pH,total nitrogen,and total phosphorus,etc.)in the 0-20 cm and 20-40 cm soil layers were systematically measured.The research results indicated that:1)With the increase of vegetation restora-tion years,the structure of soil aggregates underwent significant changes.Among them,the proportion of large aggre-gates larger than 2 mm showed a significant increase trend(an increase of 50.76%),while the proportion of micro aggre-gates smaller than 0.25 mm decreased significantly(a decrease of 44.24%).The mean weight diameter(MWD)and geometric mean diameter(GMD)increased by 17.90%and 18.42%,respectively,indicating that the stability of soil aggregates was significantly enhanced with increasing forest age.2)Through Mantel analysis,it was found that forest age,soil depth,and chemical factors had a significant impact on soil organic carbon(SOC)accumulation(P<0.01).At the same time,forest age and chemical factors had a significant impact on aggregate stability(P<0.05).The trend of changes in surface soil(0-20 cm)and deep soil(20-40 cm)was basically consistent,but the response of deep soil to en-vironmental factors was relatively lagging behind.3)Random forest analysis showed that ammonia nitrogen(NH+4-N),pH,total phosphorus(TP),and nitrate nitrogen(NO-3-N)had the highest explanatory power for soil aggregate stability.In summary,long-term vegetation restoration can effectively improve the soil structure of industrial and mining waste-lands,promote the accumulation and sequestration of soil organic carbon,and provide new ideas for the restoration and reconstruction of degraded ecosystems.