高寒半湿润沙化地土壤养分对植被恢复的响应研究

Response of sediment nutrients to plant restoration in alpine,cold and sub-humid desert land

土壤养分是沙化地生态恢复的重要基础和衡量指标,但高寒沙化地相关研究缺乏。为探究土壤养分随高寒半湿润沙化地恢复的变化过程,本研究利用老芒麦(Elymus sibiricus L.)进行植被恢复来治理沙化地,在不同的恢复年限和季节来研究土壤碳、氮、磷对植被持续恢复的响应过程。结果表明:高寒沙化地中土壤碳、氮、磷积极响应植被恢复过程,植被恢复促进了土壤中有机碳、溶解性有机碳、全氮、硝态氮、铵态氮、全磷和有效磷的增加,恢复3年后土壤有机碳增加至6.6 g/kg(0~15 cm),土壤全氮增加至0.4 g/kg(0~15 cm),土壤全磷增加至0.6 g/kg(0~15 cm);植被恢复改变了土壤有机碳季节性变化趋势,但没有改变氮和磷季节性变化趋势。植被重建促进高寒沙化地土壤养分增加,植被恢复是高寒地区沙化治理的有效手段。

Soil nutrient is an important material foundation and evaluation index to a desert land restoration.However,there is few research on the alpine and cold area.In order to investigate the variation process of soil nutrient under the vegetation restoration in the alpine,cold and sub-humid desert land,revegetation by Elymus sibiricus L.was used to study the response of the sediment carbon,nitrogen and phosphate during a continuous restoration progress of desert land in different years and seasons.Results showed that there was a positive response of the sediment carbon,nitrogen and phosphate to plant restoration,and plant restoration promoted the sediment organic carbon,dissolved organic carbon,total nitrogen,nitrate nitrogen,ammonium nitrogen,total phosphate and available phosphate.Sediment organic carbon,total nitrogen and total phosphate significantly increased to 6.6 g/kg(0~15 cm),0.4 g/kg(0~15 cm),and 0.6 g/kg(0~15 cm)respectively after three years restoration.Plant restoration changed the seasonal patterns of sediment organic carbon content,while the nitrogen and phosphate remained the origin status.Revegetation in alpine and cold desert land promoted the sediment nutrient accumulation and was an important way to restore the desert land.