摘要
为进一步揭示典型高寒地区紫花针茅草原退化进程中土壤有机碳含量及组分的变化规律,在具有典型特征的高寒草原设置了不同退化程度的研究样地,进行了野外观测、土壤样品采集、室内冻融作用处理,测定了土壤有机碳含量,分析了不同冻结时间、不同冻融循环次数对退化草原土壤有机碳含量及组分的作用规律。结果表明:较长冻结时间处理下,土壤有机碳、轻组有机碳含量呈增加趋势,重组有机碳含量呈减少趋势,从未退化到重度退化,有机碳、轻组有机碳含量增幅范围分别为1.34%~3.00%、7.75%~34.48%,重组有机碳含量减少幅度为1.83%~6.08%;随着冻融循环次数的增加,土壤有机碳、重组有机碳含量总体呈减少趋势,轻组有机碳含量则呈增加趋势,从未退化到重度退化,土壤有机碳、重组有机碳含量减少幅度分别为4.65%~35.68%、10.99%~55.17%,轻组有机碳含量的增幅范围为12.41%~51.11%。说明不同冻结时间、不同冻融循环次数对不同退化程度草地土壤有机碳含量及组分的影响不同,冻融循环次数总体上较冻结时间对土壤有机碳含量及组分的影响更明显;草地退化程度不同,对冻结时间、冻融循环次数的响应不同,冻结时间、冻融循环次数对重度退化程度草地土壤有机碳含量及组分的影响更显著,反映出高寒草原退化程度越重、土壤冻融循环次数越多越不利于草地土壤有机碳的稳定,并对土壤碳循环过程产生影响。
In order to further reveal the changes of soil organic carbon content and composition in the degradation process of a typical alpine cold area Stipa purpurea steppe,study plots with different degrees of degradation in the alpine grassland with typical characteristics was set up. Those methods were carried out,including field observation,soil sample collection,indoor freezing-thawing treatment,the determination of soil organic carbon contents,the analysis on the action of different freezing time and different freezing-thawing cycles on soil organic carbon content and composition of degraded grassland. The results showed that under longer freezing time treatment,the contents of soil organic carbon and light fraction organic carbon showed an increasing trend,but those of heavy fraction organic carbon showed a decreasing trend,from no degradation to heavy degradation,the increasing ranges of organic carbon contents and light fraction organic carbon contents were 1.34%-3.00% and 7.75%-34.48%,respectively,the decreasing ranges of heavy fraction carbon contents were 1.83%-6.08%. With the increase of freezing-thawing cycles,the contents of soil organic carbon and heavy fraction organic carbon showed a decreasing trend,but those of light fraction organic carbon showed an increasing trend,from no degradation to heavy degradation,the decreasing ranges of organic carbon contents and heavy fraction organic carbon contents were 4.65%-35.68% and 10.99%-55.17%,respectively,the increasing ranges of light fraction carbon contents were 12.41%-51.11%. The results suggested that different freezing time or different freezing-thawing cycles had different effect on soil organic carbon contents and composition in grassland with different degradation degrees. On the whole,freezing-thawing cycles had more obvious effect on soil organic carbon contents and composition than freezing time. With different degradation degrees of grassland,the responses of freezing time or freezing-thawing cycles were different. Freezing time or freezing-thawing cycles had more significant effect on soil organic carbon contents and composition in grassland of heavy degradation. The results suggested that the more serious degradation degree of alpine grassland or the more freezing-thawing cycles are less stable for grassland soil organic carbon,and have more effect on soil carbon cycle process.
作者
柴瑜
刘育红
魏卫东
CHAI Yu;LIU Yuhong;WEI Weidong(College of Agriculture and Animal Husbandry,Qinghai University,Xining 810016,China)
出处
《黑龙江畜牧兽医》
CAS
北大核心
2019年第13期97-102,共6页
Heilongjiang Animal Science And veterinary Medicine
基金
国家自然科学基金项目(31560167
31460151)
青海省科技厅应用基础研究计划项目(2015-ZJ-715)
关键词
高寒草原
退化
冻结时间
冻融循环次数
土壤有机碳含量
有机碳组分
alpine grassland
degradation
freezing time
freezi ng - thawi ng cycle
soil organic carbon content
organic carbon composition
