浑善达克沙地不同龄级沙柳灌丛土壤有机碳研究

目的]研究浑善达克沙地不同龄级人工沙柳灌丛土壤有机碳分布规律,为进一步研究干旱区群落演替过程中碳收支以及生态恢复过程中的植被类型选择提供科学依据。方法]对浑善达克沙地不同龄级(2、4、6、8 a)人工沙柳灌丛土壤p H、容重、有机碳、碳密度进行研究。结果]土壤p H在7.34~7.60,且与土壤有机碳的变化无明显相关性。同一龄级植被垂直分布上,表层土壤容重较底层低,与土壤有机碳含量的变化呈负相关。土壤有机碳在0.44~1.10 g/kg,不同龄级沙柳灌丛不同土层土壤有机碳含量均随林龄的增加出现先减低后升高的趋势,同一龄级沙柳灌丛不同土层的土壤有机碳含量无明显的变化规律。表层土壤碳密度随着龄级的增大呈先降低后增加的趋势。8 a沙柳灌丛土壤碳密度最高,为9.59 kg/m~2;随着土层的加深土壤碳密度不断增大。结论]沙柳灌丛对沙地植被恢复、土壤碳库有重要作用。

Study on Soil Organic Carbon of Different Age Classes of Salix psammophila Shrubs in the Hunshandake Sand Land

Objective] To study distribution regularities of soil organic carbon of different age classes of Salix psammophila shrubs in the Hunshandake Sand Land,in order to provide a scientific basis for further study on carbon budget in the process of community succession and selection of vegetation types in the process of ecological restoration.Method] The soil pH,bulk density,organic carbon and carbon density of the different ages (2,4,6,8 a) of artificial Salixpsammophila shrubs in Hunshandake Sand Land were studied.Result]The results showed that the soil pH of Salix psammophila shrubs was 7.34-7.60.There was no significant correlation between soil pH and soil organic carbon content.In the vertical distribution of vegetation in the same age,the bulk density of the surface layer was lower than that of the bottom layer,and it was negatively correlated with the change of soil organic carbon.The contents of soil organic carbon in different ages of Salix psammophila shrubs were between 0.44 and 1.10 g/kg.Both of the different ages of Salix psammophila shrubs and the soil organic carbon content in different soil layers with the increase of woods' ages showed a trend from decline to rise,there was no obvious change of soil organic carbon in different soil layers of Salix psammophila shrubs.The soil carbon density in the soil surface decreased first and then increased with the increase of age.The soil carbon density of 8 a Salix psammophila shrubs was 9.59 kg/m2,and the soil carbon density increased with the increase of soil level.Conclusion] The results display that Salix psammophila shrubs play an important role in vegetation restoration and soil carbon pool.