不同退化程度高寒草甸土壤团聚体养分及生态化学计量特征研究  

Ecological stoichiometry characteristics of soil aggregates in alpine meadows with differing degrees of degradation

作　　者：李林芝[1,2] 张德罡[1] 马源 罗珠珠[2] 林栋[1] 海龙[2] 白兰鸽 LI Lin-zhi;ZHANG De-gang;MA Yuan;LUO Zhu-zhu;LIN Dong;HAI Long;BAI Lan-ge(College of Pratacultural Science,Gansu Agricultural University,Lanzhou 730070,China;College of Resources and Environmental Sciences,Gansu Agricultural University,Lanzhou 730070,China;Academy of Animal Husbandry and Veterinary Science,Qinghai University,Xining 810016,China)

机构地区：[1]甘肃农业大学草业学院,甘肃兰州730070 [2]甘肃农业大学资源与环境学院,甘肃兰州730070 [3]青海大学畜牧兽医科学院,青海西宁810016

出　　处：《草业学报》2023年第8期48-60,共13页Acta Prataculturae Sinica

基　　金：甘肃省自然科学基金(21JR7RA826,21JR7RA830);国家自然科学基金(32260354)资助

摘　　要：土壤结构中养分的稳定性与高寒草甸生态系统的稳定息息相关,为阐明退化对高寒草甸土壤团聚体养分和生态化学计量特征的影响,在甘肃省天祝藏族自治县金强河流域设置未退化(ND)、轻度退化(LD)、中度退化(MD)和重度退化(SD)4个不同退化程度的高寒草甸,采用干筛法对0~30 cm土层土壤团聚体有机碳、全氮和全磷含量及生态化学计量分布特征进行研究。结果表明:高寒草甸土壤团聚体内有机碳、全氮含量随退化程度加剧呈先上升后降低的趋势,全磷含量随退化加剧呈“V”形分布,碳、氮、磷在0.25~0.50 mm粒级含量最高。草地退化使土壤团聚体C/N降低,C/P和N/P则随退化加剧呈先上升后下降趋势,土壤团聚体C/N、C/P和N/P均随土层加深而逐渐下降。统计分析表明土壤各粒级团聚体所占组分是影响团聚体养分含量的关键因素。从生态化学计量学角度分析,N和P是高寒草甸退化过程中的主要养分限制因子。The stability of alpine meadow ecosystems is closely related to soil structural integrity and nutrient retention.This research sought to clarify the effects of degradation on soil nutrient status and nutrient stoichiometric changes of soil aggregates in alpine meadows with differing degrees of degradation.The research was conducted at the Jinqianghe alpine meadow in Tianzhu County,Gansu Province.Soils with four differing degrees of degradation were selected:No degradation(ND),light degradation(LD),moderate degradation(MD)and severe degradation(SD).Soil samples from the 0-30 cm soil layer were used to study the soil aggregate nutrient status and stoichiometric changes in these four degradation categories by the dry-sieving method.It was found that the organic carbon and total nitrogen in soil aggregates in alpine meadow increased initially and then decreased with increasing degradation,while soil aggregate total phosphorus exhibited a‘V’-shaped distribution with increasing degradation.The highest contents of organic carbon,total nitrogen and total phosphorus in soil aggregates were in peds 0.25-0.50 mm in size.The C∶N of soil aggregates decreased with increasing degradation.C∶P and N∶P of soil aggregates increased initially and then decreased with increasing degree of deterioration.C∶N,C∶P and N∶P of soil aggregates decreased gradually with increase in soil depth.The results reveal the distribution characteristics of soil aggregate nutrient content and ecological stoichiometry in soils with different degrees of degradation,and thus provide information relevant to the restoration and development of alpine meadow.The composition of soil aggregates is the key factor affecting the nutrient content of soil aggregates.From the perspective of ecological stoichiometry,N and P are the main nutrient limiting factors in the process of alpine meadow degradation.

关 键 词：高寒草甸 退化程度 土壤团聚体 团聚体养分 生态化学计量特征 粒级 

分 类 号：S812.2[农业科学—草业科学]