摘要
植物-土壤作为构成生态系统养分循环的连续体,在某种程度上决定了草地生态系统的养分平衡和系统稳定性。碳(C)、氮(N)和磷(P)是生态系统中三种主要的营养元素,它们参与了生态系统的养分循环,在生态系统结构功能维持中起着基础性作用,且生态系统内部的C、N、P循环在植物、土壤和微生物之间相互转换。为了探究黄帚橐吾(Ligularia virgaurea)在扩散过程中对草地生态系统养分循环的影响,以黄帚橐吾微斑块为研究对象,根据斑块密度界定6个密度梯度,分别为D0(0株/m~2)、D1(43株/m~2)、D2(99株/m~2)、D3(163株/m~2)、D4(332株/m~2)和D5(621株/m~2),分析了不同密度斑块的草地植物、土壤和土壤微生物生物量C、N、P含量及其生态化学计量的变化情况。结果表明,随着黄帚橐吾密度的增大,草地植物群落的C含量呈增加趋势,植物N含量略微上升后显著下降,且当黄帚橐吾密度≥160株/m~2时,植物N含量显著降低,植物P含量呈先降低后升高的趋势,C∶N比呈逐渐上升趋势,C∶P比呈先上升后降低趋势,N∶P比呈先上升后降低趋势;土壤C、N、P含量均呈先增加后降低趋势,其中C含量在D2达到最大值,N含量为D1—D4高于D0和D5,但各斑块差异不显著,P含量为D3显著高于其余斑块,C∶N在D5达到最大值,C∶P在D2达到最大值,土壤N∶P呈略微降低后又有所增加,土壤养分主要受N限制;MBC随着黄帚橐吾密度的增加有降低趋势,而MBN和MBP变化均表现为“N”字型,MBN∶MBP呈先增加后降低趋势。通过相关性分析和RDA分析得到,黄帚橐吾密度与植物C、N、MBN以及MBP显著相关,植物C含量和土壤C含量与MBN呈显著正相关,土壤养分与微生物量的关系更为密切。
As a continuum of ecosystem nutrient cycle,plant-soil determines the nutrient balance and system stability of grassland ecosystem to some extent.Carbon,nitrogen and phosphorus are the three main nutrient elements in the ecosystem,they participate in the nutrient cycle of the ecosystem,and play a fundamental role in the maintenance of the ecosystem structure and function,and the C,N,and P cycles within the ecosystem were transformed among plants,soils,and microorganisms.In order to explore the effect of Ligularia virgaurea on nutrient cycling in grassland ecosystem during its diffusion process,the micropatches of L.virgaurea were taken as the research object.Six density gradients were defined according to the patch density.The changes of C,N and P in grassland plants,soil and soil microbial biomass and their ecological stoichiometry of 6 different density patches of L.virgaurea were analyzed,which were D0(0 plant/m~2),D1(43 plant/m~2),D2(99 plant/m~2),D3(163 plant/m~2),D4(332 plant/m~2) and D5(621 plant/m~2),respectively.The results showed that with the increase of L.virgaurea density,the C content of grassland plant community presented an increasing trend,plant N content increased slightly and then decreased significantly,when the density of L.virgaurea was equal or greater than 160 plants/m~2,the plant N content decreased significantly.Plant P content decreased at first and then increased,plant C∶N ratio showed a gradual upward trend,C∶P ratio increased at first and then decreased,N∶P ratio increased at first and then decreased.The contents of C,N and P in soil increased at first and then decreased,in which C content reached the maximum at D2,and the N content of D1—D4 is higher than that of D0 and D5,but there was no significant difference among patches.P content in D3 was significantly higher than that in other patches.Soil nutrients were mainly limited by nitrogen.Soil microbial biomass carbon tended to decrease with the increase of L.virgaurea density,while the changes of microbial biomass nitrogen a
作者
王宏生
王玉琴
宋梅玲
周睿
WANG Hongsheng;WANG Yuqin;SONG Meiling;ZHOU Rui(Key Laboratory of the Alpine Grassland Ecology in the Three Rivers Region(Qinghai University),Ministry of Education,Qinghai University Academy of Animal and Veterinary Sciences,Xining 810016,China)
出处
《生态学报》
CAS
CSCD
北大核心
2024年第10期4297-4307,共11页
Acta Ecologica Sinica
基金
青海省科技厅应用基础研究项目(2023-ZJ-723)
国家自然科学联合基金项目(U21A20186)
青海大学教育部重点实验室自主课题(2023-SJY-ZZ-01)
青海省“高端创新创业人才计划”拔尖人才培养计划项目。
关键词
黄帚橐吾
密度斑块
养分循环
化学计量特征
Ligularia virgaurea
density patch
nutrient cycle
stoichiometric characteristics
