摘要
为探究阻沙固沙带土壤养分及生态化学计量对阻沙固沙措施的反馈效应,并阐明其对环境因子的生态学响应,在民勤绿洲西北缘选择典型的阻沙固沙带,沿主导风向在阻沙固沙带内选择5处样地作为试验组,以流动沙丘和农田作为对照组,采集表层(0~10 cm)土样,测定土壤有机碳(SOC)、全氮(TN)、全磷(TP)、全钾(TK)含量和pH、含水量、电导率,分析土壤养分含量和生态化学计量比特征以及环境因子对其贡献率。结果表明:研究区土壤SOC含量在各样点呈现出显著差异,农田为19.87 g/kg,阻沙固沙带为7.75 g/kg,流动沙丘为3.59 g/kg;土壤TN和TP含量均处于较低水平,其平均值分别为0.09 g/kg和0.44 g/kg;土壤TK含量除在流动沙丘较低外,在其他样点含量较高,平均值为8.79 g/kg。土壤C∶N的平均值为161.23,远高于我国表层土壤C∶N的平均值;土壤C∶P平均值为26.56,N∶P平均值为0.21,均远低于我国平均水平,阻沙固沙带土壤存在显著的氮限制特征且有机质的矿化过程缓慢,但土壤磷矿化能力较强,磷素有效性较高。主成分分析表明,对土壤SOC、TN、TP、TK含量及其生态化学计量特征影响最大的环境因子为含水量,贡献率达到87.1%,pH的贡献率为11.3%,电导率的贡献率相对较低,仅为1.6%。综上,阻沙固沙带较好地改善了沙化土壤的养分状况,水分和氮素是限制阻沙固沙带土壤养分状况的主导因子。
The aim of this article is to explore the feedback of soil nutrients and their ecological stoichiometry to sand-blocking and fixation methods,and to clarify their ecological responses to environmental factors in sand-blocking and fixation zone(SBFZ).Research was conducted on five sample plots at a typical SBFZ in the northwest of Minqin oasis along the prevailing wind direction.Plots in shifting dune and farmland were selected as control groups.Surface soil(0~10 cm)was collected to measure the soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP),total potassium(TK),pH,water content and electrical conductivity for the analysis of soil nutrition content,the characteristics of ecological stoichiometric ratios,and the contribution of environmental factors.The results showed that the SOC varied significantly in different sample plots,i.e.19.87 g/kg in the farmland,7.75 g/kg in the SBFZ,and 3.59 g/kg in the shifting dune.Levels of TN and TP contents were relatively low,with 0.09 g/kg and 0.44 g/kg on average,respectively.Except in the shifting dune,the content of TK there was a relatively high mean value of 8.79 g/kg.The mean C∶N ratio(161.23)was significantly higher compared with of China's average,while C∶P(26.56)and N∶P(0.21)were significantly lower than Chinese average.The feature of"nitrogen limitation"was identified in the soil of SBFZ and the mineralization process of organic matter was slow.However,soil exhibited strong capacity of phosphate mineralization and the availability of phosphorus was high.Principal component analysis showed that water content was the dominant environmental factor affecting SOC,TN,TP,and TK contents,as well as their ecological stoichiometric characteristics,with a contribution rate of 87.1%.The contribution rate of pH was 11.3%,whereas electrical conductivity contributed only 1.6%.In summary,the nutrient and ecological status of sandy soil was improved in the SBFZ.The deficient of water and nitrogen was the primary limiting factors for soil nutrient status in the sand-blocking and fixation zone.
作者
刘腾
马瑞
田永胜
张春来
LIU Teng;MA Rui;TIAN Yongsheng;ZHANG Chunlai(College of Forestry,Gansu Agricultural University,Lanzhou 730070,China;Faculty of Geographical Science,Beijing Normal University,Beijing 100875,China)
出处
《中国草地学报》
北大核心
2025年第5期12-20,共9页
Chinese Journal of Grassland
基金
国家自然科学基金区域创新发展联合基金项目(U21A2001)。
关键词
民勤绿洲
阻沙固沙带
土壤养分
生态化学计量
Minqin oasis
Sand-blocking and fixation zone
Soil nutrient
Ecological stoichiometry
