毛乌素沙地黑沙蒿对邻近草本植物氮吸收速率及比例的影响  

Effects of Artemisia ordosica on the nitrogen uptake rate and proportion of associated herbaceous plants in the Mau Us Sandy Land

作　　者：苗春 刘靓 朱冠男 白宇轩 佘维维[1,2] 秦树高[1,2] 郭焱培 张宇清[1,2] MIAO Chun;LIU Liang;ZHU Guan-Nan;BAI Yu-Xuan;SHE Wei-Wei;QIN Shu-Gao;GUO Yan-Pei;and ZHANG Yu-Qing(Yanchi Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;State Key Laboratory of Efficient Production of Forest Resource,Beijing Forestry University,Beijing 100083,China;Key Laboratory of State Forestry and Grassland Administration on Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学水土保持学院,宁夏盐池毛乌素沙地生态系统国家定位观测研究站,北京100083 [2]北京林业大学林木资源高效生产全国重点实验室,北京100083 [3]北京林业大学水土保持国家林业和草原局重点实验室,北京100083

出　　处：《植物生态学报》2025年第3期446-459,共14页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(U22A20504 and 32071844)。

摘　　要：氮是维系植物群落物种多样性的关键养分元素。在氮贫乏的荒漠生态系统中,固沙植物群落种间互作如何影响各功能群植物种氮吸收模式,目前仍不明确。该研究基于野外植物种移除实验平台,以毛乌素沙地黑沙蒿(Artemisia ordosica)固沙植物群落为研究对象,设置移除黑沙蒿和保留黑沙蒿两种处理,采用15N标记技术,探究黑沙蒿对3种邻近功能群草本植物(一年生草本、多年生禾草、多年生杂类草)及草本群落的硝态氮、铵态氮和甘氨酸吸收速率和比例的影响;同时测定各处理土壤铵态氮、硝态氮、全氮及可溶性有机氮含量、土壤含水率、地表透光率等环境因子,分析各功能群草本植物及草本群落对不同形态氮的吸收速率、比例及其与环境因子的关系。研究结果显示:(1)无机氮和小分子有机氮是黑沙蒿群落草本植物的有效氮源,所有功能群植物及草本群落对各形态氮的偏好顺序为硝态氮>铵态氮>甘氨酸;(2)移除黑沙蒿后,一年生草本、多年生禾草及草本群落的氮吸收速率分别增加了48.32%、129.77%和55.53%,多年生禾草对硝态氮的吸收比例增加了10.65%;(3)黑沙蒿通过改变其株丛下局部环境,尤其是降低透光率和土壤硝态氮含量,影响草本植物的氮吸收模式;(4)黑沙蒿群落中各功能群草本植物氮吸收速率及比例受不同环境因子影响,其中多年生禾草表现出灵活的氮源可塑性和较高的氮利用效率。研究发现,草本植物差异化的氮获取策略,可能是黑沙蒿群落中植物应对种间氮竞争和资源短缺、提高群落稳定性和恢复力的重要机制;多年生禾草凭借其灵活的氮源转换和高效吸收能力,可能会成为未来群落的优势功能群。该研究结果有助于理解典型固沙植物群落中不同功能群物种的养分竞争和共存机制,为荒漠化地区植被恢复和管理提供科学依据。Aims Nitrogen is a key nutrient element for maintaining species diversity in plant communities.In nitrogen-limited desert ecosystems,the impact of interspecific interactions within sand-fixed plant communities on nitrogen uptake rates and distribution among different functional groups of plants remains unclear.Methods A field experiment was conducted in the Mau Us Sandy Land,northern China,with two treatments:removal of Artemisia ordosica and a control that retained A.ordosica.Nitrogen uptake rate and proportion of nitrate nitrogen,ammonium nitrogen,and glycine by three associated functional groups of herbaceous plants(annual herbaceous,perennial grasses,and perennial forbs)and the overall herbaceous community,were measured using 15N isotope labeling.Environmental factors,such as soil ammonium nitrogen,nitrate nitrogen,total nitrogen,soluble organic nitrogen content,soil moisture,and plot light transmittance were also determined.Additionally,the relationships between nitrogen uptake rate,proportion and environmental factors for each functional group and herbaceous community were analyzed.Important findings Inorganic nitrogen and micromolecular organic nitrogen were effective nitrogen sources for herbaceous plants in A.ordosica community.The preference of herbaceous plants for different forms of nitrogen followed the order:nitrate nitrogen,ammonium nitrogen,and micromolecule organic nitrogen.After the removal of A.ordosica,the nitrogen uptake rate of annual herbaceous,perennial grasses,and the overall herbaceous community increased by 48.32%,129.77%,and 55.53%,respectively,with perennial grasses showing a 10.65%increase in the proportion of nitrate nitrogen uptake.Artemisia ordosica affected the nitrogen uptake absorption mode of herbaceous plants by altering the microenvironment under the plants,particularly by reducing plot light transmittance and soil nitrate nitrogen content.Nitrogen uptake rate and proportion among different functional groups of herbaceous plants were influenced by various environmental facto

关 键 词：种间互作 黑沙蒿 氮吸收效率 氮吸收比例 毛乌素沙地 

分 类 号：Q948[生物学—植物学]