【作者】 孙国荣； 陈刚； 彭永臻； 岳中辉； 马东辉； 那守海； 阎秀峰；

【Author】 SUN Guo-Rong~(1,3) CHEN Gang~(1,2) PENG Yong-Zhen~(3,4) MA Dong-Hui~5 YUE Zhong-Hui~6 NA Shou-Hai~7 YAN Xiu-Feng~7 (1.College of bioscience and Biotechnology,Yangzhou University,Yangzhou 225009,China;2.Key Laboratory of Crop Genetics and Physiology of Jiangsu Province,Yangzhou University,Yangzhou 225009, China;3.School of Municipal and Environmental Engineering,Harbin Institute of Technology,Harbin 150009,China;4.College of Environmental and Energy Engineering,Beijing Polytechnic University,Beijing 100022,China:5.Institute for Vegetable Science,University Hannover,Herrenhaeuserstr.2,30419 Hannover, Germany;6.Department of Biology,Harbin Normal University,Harbin 150080,China;7.College of Life Science,Northeast Forestry University,Harbin 150040,China)

【机构】 扬州大学生物科学与技术学院； 哈尔滨工业大学市政环境工程学院； 扬州大学江苏省作物遗传生理重点实验室； 北京工业大学环境与能源工程学院； 哈尔滨师范大学生物系； Institute for Vegetable Science,University Hannover,Herrenhaeuserstr.30419 Hannover,Germany； 东北林业大学生命科学学院；

【摘要】 通过对星星草(Puccinellia tenuiflora)生长不同年数盐碱土壤氮素营养状况的比较研究氮素沉积作用机理,并探讨其在植被演替中的可能作用。结果表明:在一维生态位空间(土壤氮含量)星星草和羊草(Leymus chinense)之间具有较小的生态位分离值和较大的生态位重叠值,表明羊草对土壤高含氮量具有较强的竞争能力。这些也许是羊草以及其他植物在星星草生长一定年数后能够侵入碱斑土壤的机制。星星草作为盐碱土壤改良和植被恢复的先锋植物,它的生长增强了盐碱草地土壤氮素的矿质化作用和生物固氮强度,并减弱了氮素随地表径流的损失。最终促进了盐碱草地的氮素沉积达到了适合于其它物种(如羊草)生长的水平,从而碱斑植被得以恢复。更多还原

【Abstract】 With the exploitation and utilization of human,especially the non-sustainable utilization like over-grazing,the extent of alkalization of Song-Nen grassland has been enlarged and the vegetation has been degenerated seriously.Thus the area of preponderant grass Leymus chinense(L chinense) reduced,the height of grass and the extent of close canopy of grassland decreased,and the alkali spot with very little grass occurred in the grassland.Puccinellia tenuiflora(P.tenuiflora) could grow in alkalized soil after artificial planting,and ameliorate the alkalized soil.Then L chinense and other plants intruded into the alkalized spot where P. tenuiflora had been grown a certain years,making the plant population no longer the singularity population of P.tenuiflora.The mechanism about the vegetation of L chinense succeed in recovery was not only due to the improvement of physical or chemical property of the soil,but also due to the anthropogenic nitrogen deposition, which could cause vegetation-type conversion.But the mechanisms of vegetation change were not very clear. As to the caused of vegetation change,there were many hypotheses,including frequent fire and grazing,but nitrogen deposition had only been considered recently. There were two aims of this study on the growth of P.tenuiflora.The first was to reveal that how the P. tenuiflora could meliorate the alkalized soil,the second was to quantify the changes of niche after the vegetation succession from P.tenuiflora to other kind of plants.Niches of various plants in Song-Nen alkaline grassland were calculated.Comparing with the controlled alkali spot soil,all the evidences from the experiment indicated that P.tenuiflora improved the nitrogen nutrition status of alkalized soil.There were smaller value of niche separation and bigger value of niche overlap between P.tenuiflora and L.chinense in one dimension niche space(N content of soil) than those among other species,which indicated that L chinense had stronger competition ability on soil with high nitrogen content.These may be the mechanism of L chinense and other plants intrude into the alkalized spot in which P.tenuiflora has grown certain years.As the pioneer plant of meliorating alkalized soil and vegetation restoration,the growth of P.tenuiflora could improve the nitrogen mineralization and nitrogen fixation in alkalized grassland,and decrease the nitrogen loss with water run-off. So,the nitrogen deposition in alkalized grassland was improved to the level that other plants(such as L chinense) could grow normally,and the vegetation in alkali spot was finally restored.更多还原