Distribution and influencing factors of the readily-oxidizable organic carbon in tropical virgin forest soils at different altitude gradients on Hainan Island
[Objective]This study investigated the distribution patterns and influencing factors of readily-oxidable organic carbon in soils across different altitude gradients within tropical island virgin rain-forests,aimed at establishing a theoretical foundation for the rational assessment and scientific management of soil carbon pools in the tropical rainforests of Hainan.[Method]Forest soils from a typical tropical prime-val rainforest area in southeastern Hainan Island were selected as the research object.The study measured the content of readily oxidizable organic carbon in the soil,along with analyzing the soil's physical and chemi-cal properties.The distribution patterns and influencing factors of this carbon component were examined in different soil layers across varied altitude gradients.[Result]The results indicated that the average content of readily oxidizable organic carbon in the 0～60 cm soil layer of the typical primitive tropical rainforest area in southeastern Hainan Island was 4.22 g/kg,with a range of variation from 2.31 to 8.11 g/kg.Notably,in the forest soil profiles at different altitude gradients,the content of readily oxidizable organic carbon was highest in the 0～20 cm soil layer,accounting for 44.81%in Qixianling,42.97%in Wuzhishan,and 47.89%in Diaoluoshan.Furthermore,within the same soil layer across different altitude gradients,the con-tent of readily oxidizable organic carbon in Wuzhishan and Diaoluoshan Nature Reserves exhibited a pattern of initially decreasing and then increasing with altitude.Conversely,in Qixianling National Forest Park,the content displayed a pattern of initially increasing,then decreasing,and finally increasing with altitude.More-over,a significant positive correlation was observed between the content of readily oxidizable organic carbon and altitude(P<0.01),with a correlation coefficient of 0.608,while an equally significant negative correla-tion was found with soil pH(P<0.01),yielding a correlation coefficient of-0.366.There was no significant correlation with soil particle composition.[Conclusion]The content of readily oxidizable organic carbon in the soil exhibited a notable"surface aggregation"phenomenon in the study area.Additionally,different changing trends were observed in the content of readily oxidized organic carbon in forest soils at various points in the study area with increasing altitude,highlighting altitude and pH as key influencing factors in the distribution pattern of this carbon component in the forest soils of the area.
soil readily oxidizable organic carbonaltitude gradientPearson correlation analysisregres-sion model constructionHainan Island
万方数据
维普
