岩溶区固氮植物适应土壤氮素变化的潜在策略  

Potential strategy of nitrogen-fixing plants adapting to soil nitrogen change in karst regions

作　　者：潘复静 章润阳 秦国鑫 陈英倩 梁月明[3] 刘坤平[4] 张伟[4] PAN Fu-jing;ZHANG Run-yang;QIN Guo-xin;CHEN Ying-qian;LIANG Yue-ming;LIU Kun-ping;ZHANG Wei(College of Environmental and Engineering,Guilin University of Technology,Guilin 541006,China;Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology for Science and Education Combined with Science and Technology Innovation Base,Guilin University of Technology,Guilin 541006,China;Key Laboratory of Karst Dynamics,Ministry of Natural and Resources,Guangxi Zhuang Autonomous Region,Institute of Karst Geology,Chinese Academy of Geological Sciences,Guilin 541004,China;Huanjiang Observation and Research Station for Karst Ecosystems,Huanjiang 547100,China)

机构地区：[1]桂林理工大学环境科学与工程学院,广西桂林541006 [2]桂林理工大学广西环境污染控制理论与技术重点实验室科教结合科技创新基地,广西桂林541006 [3]中国地质科学院岩溶地质研究所,自然资源部、广西壮族自治区岩溶动力学重点实验室,广西桂林541004 [4]中国科学院环江喀斯特生态系统观测研究站,广西环江547100

出　　处：《桂林理工大学学报》2021年第4期869-876,共8页Journal of Guilin University of Technology

基　　金：国家自然科学基金项目(41907208,31800441);广西自然科学基金项目(2018GXNSFBA138012,2017GXNSFAA198241);广西高等学校高水平创新团队及卓越学者计划项目(桂财教函[2018]319)。

摘　　要：固氮植物是生态系统中缓解氮限制的重要组成部分,植被恢复中伴随着土壤氮含量的升高,固氮植物适应土壤氮素变化的策略还需进一步了解。以岩溶区香合欢(Albizia odoratissima)与木豆(Cajanus cajan)两种固氮植物为研究对象,通过氮肥添加盆栽试验,研究氮肥添加对岩溶区固氮植物和土壤养分变化的影响。结果显示:添加氮肥情况下岩溶区两种固氮植物根际土的全磷、有效磷、铵态氮含量显著高于不添加氮肥的情况,而硝态氮的差异不明显。氮肥添加下,两种固氮植物的总生物量升高,但是根冠比和固氮速率降低,表明岩溶区两种固氮植物潜在性地采用兼性固氮策略。另外,不添加氮肥情况下,香合欢的根冠比、根系的氮磷含量与茎、叶的氮含量、固氮速率、菌根侵染率、根系磷酸酶活性高于木豆;添加氮素情况下,木豆的菌根侵染率和根系磷酸酶活性高于香合欢。以上试验结果表明,在岩溶区生态恢复早期进行人工干预时选择香合欢作为植物群落配置的物种可能更合适,而在生态恢复后期选择木豆作为植物群落配置的物种可能更合适。To determinate potential strategy of nitrogen-fixing plants adapting to soil nitrogen change in karst region,two nitrogen-fixing plants(Albizia odoratissima and Cajanus cajan)were selected to explore this issue in experiment.The results showed that TP,AP,NH_(4)^(+)-N contents in rhizosphere soil of two nitrogen-fixing plants in nitrogen application soils were significantly higher than those in blank group soils,except NO_(3)^(-)-N contents.The total biomass of karst nitrogen-fixing plants increased,but the root-shoot ratios and nitrogen fixation rates decreased under the nitrogen application soils.The two nitrogen-fixing plants had the facultative nitrogen fixation strategy in karst region.In blank group soils,the root-shoot ratio,N and P contents of roots,N contents of stems and leaves,nitrogen fixation rate,arbuscular mycorrhizal fungi(AMF)colonization,and root phosphatase activity of A.odoratissima were higher than those parameters of C.cajan.In nitrogen application soils,the AMF colonization and root phosphatase activity of C.cajan were higher than those parameters of A.odoratissima.The above results suggested that A.odoratissima might be applicable in adding into the artificial plant community of early vegetational successions when some ecological restoration projects were carried out in this region,while C.cajan might be applicable in adding into the community of later vegetational successions.

关 键 词：岩溶区 固氮植物 固氮速率 菌根侵染率 磷酸酶活性 

分 类 号：Q948.1[生物学—植物学]