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Temporal And Spatial Variation Of Soil Organic Carbon In Pinus Tabulaeformis Forest In Recent 40 Years

Posted on:2020-05-18Degree:MasterType:Thesis
Country:ChinaCandidate:X X LiuFull Text:PDF
GTID:2370330575497643Subject:Soil science
Abstract/Summary:PDF Full Text Request
In this study,0-60 cm soil of Pinus tabulaeformis forest in China was used as the research object.The related data of soil organic carbon(SOC)of Pinus tabulaeformis forest in China from 1980 to 2017 were collected by literature retrieval.The spatial and temporal variation characteristics of SOC of Pinus tabulaeformis forest in China and its influencing factors were discussed by data integration,variance analysis and correlation analysis.The results showed:(1)The SOC content and density of Pinus tabulaeformis forest were mainly concentrated in the surface soil of 0-20 cm.With the increase of soil depth,SOC content and density decreased gradually.Under different age groups,SOC content and density in middle-aged and near-mature forests showed a significant decrease in the range of 0-60 cm depth,while the soil performance of young forests showed a gradual decrease.The SOC content and density of 0-60 cm decreased significantly with the increase of depth under the two forest types of Pinus tabulaeformis pure forest and mixed forest and brown soil and cinnamon soil.(2)The content and density of SOC in 0-20 cm under three age groups and two forest types were significantly different,which showed that the content and density of SOC increased significantly with the increase of forest age,and the change characteristics of mixed forest were significantly higher than that of pure forest,but the difference between different soil types were not significantly.(3)In the past 40 years,the content and density of SOC in 0-60 cm soil layers decreased first and then increased with time.Since 1990,there has been a downward trend,reaching the lowest level in 2000-2009,increasing rapidly after 2010 and returning to the level of 1980.Among them,0-20 cm SOC was significantly reduced and increased in the adjacent time stages compared with 20-60 cm soil layers.(4)SOC storage decreased from 1980 to 2009,showing that the carbon source of atmospheric CO2 increased rapidly to 226.619 Tg in 2010,showing the strong carbon sink function of soil ecosystem.(5)SOC in Pinus tabulaeformis is affected by many environmental factors.Altitude,litter amount,total nitrogen content and C/N were positively correlated with soil carbon density(P<0.01),while slope,pH value and soil bulk density were negatively correlated with soil carbon density(P<0.01).Temperature and precipitation had no significant effect on SOC in Pinus tabulaeformis forest(P>0.05).
Keywords/Search Tags:Pinus tabulaeformis forest, SOC, forest age, forest type, soil type, temporal and spatial variation, influencing factors
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