摘要
增温和氮沉降会影响青藏高原高寒草甸的功能和结构,生态化学计量学有助于揭示植物与土壤之间养分流动的生物地球化学特征。本试验通过在青海高寒草甸进行不同水平增温及氮沉降处理,增温水平分别为W0(不增温)、W1(空气温度增加0.47℃,土壤温度增加0.61℃)、W2(空气温度增加0.92℃,土壤温度增加1.09℃)、W3(空气温度增加1.44℃,土壤温度增加1.95℃),施氮水平分别为不施氮、16 kg N/(hm^(2)·a)、32 kg N/(hm^(2)·a),探究植物、土壤及酶碳氮磷化学计量变化及其相互之间的关系。结果表明:与不增温相比,增温显著增加植物地上部全氮、土壤全氮、土壤有机碳、土壤氮磷比及土壤酶氮磷比,显著降低植物地上部碳氮比、土壤酶碳氮比及土壤酶碳磷比。与不施氮相比,氮沉降显著增加植物地上部和根系全氮、土壤有机碳、土壤全氮、土壤酶碳氮比,显著降低根系碳氮比及土壤酶氮磷比。氮沉降及增温的交互作用显著影响土壤有机碳含量及土壤酶碳氮磷化学计量比。通过计算植物组织对土壤元素和酶活性响应的化学计量动态平衡指数,发现增温及氮沉降下植物组织化学计量稳态指标属于严格内稳态。土壤全氮、碳氮比、β-1,4-木糖苷酶对植物营养元素及其化学计量有显著影响。综上所述,短期增温及氮沉降处理下青藏高原高寒草甸土壤及酶化学计量会影响植物对养分的获取能力。
Warming and nitrogen deposition can affect the functions and structures of alpine meadow ecosystems on the Qinghai-Xizang Plateau.Ecological stoichiometry provides a framework to understand the biogeochemical cycling of nutrients between plant and soil.This study conducted a field experiment in an alpine meadow of Qinghai Province,to investigate the effects of different levels of warming and nitrogen deposition.The warming treatment included four levels:W0(no warming),W1(air temperature increases 0.47℃,soil temperature increases 0.61℃),W2(air temperature increases 0.92℃,soil temperature increases 1.09℃),W3(air temperature increases 1.44℃,soil temperature increases 1.95℃).Nitrogen application treatments included:N0(no nitrogen application),16 kg N/(hm^(2)·a),and 32 kg N/(hm^(2)·a).The experiment assessed changes in carbon,nitrogen,and phosphorus contents in plant and soil,soil enzyme activity,and their stoichiometric ratios,as well as the relationship among these components.The results showed as follows:Warming significantly increased total nitrogen in the aboveground plant tissues,soil total nitrogen,soil organic carbon,the soil nitrogen phosphorus ratio,and the enzyme nitrogen phosphorus ratio.Simultaneously,it significantly decreased the carbon nitrogen ratio in aboveground plant biomass,and the carbon nitrogen and carbon phosphorus ratios of soil enzymes.Nitrogen deposition significantly increased total nitrogen in both aboveground and root tissues,soil organic carbon,soil total nitrogen,and the enzyme carbon nitrogen ratio.It significantly decreased the root carbon nitrogen ratio and enzyme nitrogen phosphorus ratio.The interaction between nitrogen deposition and warming significantly affected soil organic carbon content and the carbon nitrogen,carbon phosphorus,and nitrogen phosphorus ratios of soil enzymes.Analysis of stoichiometric homeostasis in plant tissues in responses to soil elements and enzyme activities revealed strict stoichiometric homeostasis in plant tissues under both warming and nitrogen deposition.Soil total nitrogen,soil carbon nitrogen ratio,and soilβ-1,4-xylosidase activity significantly influenced plant nutrient content and stoichiometry.In summary,short-term warming and nitrogen deposition significantly alter the stoichiometry of soil and enzyme systems in alpine meadows,which in turn influences the nutrient acquisition strategies of plants on the Qinghai-Xizang Plateau.
作者
向雪梅
德科加
张琳
林伟山
冯廷旭
李菲
魏希杰
XIANG Xuemei;DE Kejia;ZHANG Lin;LIN Weishan;FENG Tingxu;LI Fei;WEI Xijie(Academy of Animal Science and Veterinary,Qinghai University,Xining 810016,China)
出处
《中国草地学报》
北大核心
2025年第5期21-33,共13页
Chinese Journal of Grassland
基金
青海省科技厅重点研发与转化计划项目(2024-NK-137)
称多县一年生饲草种子繁殖与青贮加工贮藏技术研究与示范(2024-NK-P28)
2024年度中国科协青年人才托举工程博士生专项计划。
关键词
增温
氮沉降
高寒草甸
生态化学计量
酶活性
土壤养分
植物养分
Warming
Nitrogen deposition
Alpine meadow
Ecological stoichiometry
Enzyme activity
Soil nutrients
Plant nutrients
