星星草(Puccinellia tenuiflora)人工草地氮素积累对松嫩盐碱草地植被演替的影响  

Effect of nitrogen accumulation in Puccinellia tenuiflora grassland on the succession of vegetation in Songnen alkaline grassland

作　　者：陈刚[1,2] 孙国荣[2,3] 彭永臻[3,4] 马东辉 岳中辉[6] 那守海[7] 阎秀峰[7] 

机构地区：[1]扬州大学江苏省作物遗传生理重点实验室,扬州225009 [2]扬州大学生物科学与技术学院,扬州225009 [3]哈尔滨工业大学市政环境工程学院,哈尔滨150009 [4]北京工业大学环境与能源工程学院,北京100022 [5]Institute for Vegetable Science, University Hannover, Herrenhaeuserstr, 2, 30419 Hannover, Germany [6]哈尔滨师范大学生物系,哈尔滨150080 [7]东北林业大学生命科学学院,哈尔滨150040

出　　处：《生态学报》2008年第5期2031-2041,共11页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目(30600073,30270234,30770344);国家“863”重大科技专项资助项目(2007AA021402);国家自然科学基金重点资助项目(50138010);扬州大学高层次人才科研启动基金资助项目~~

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,研究氮素积累作用的机理,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,从而使碱斑植被得以恢复。With the exploitation and utilization of land resources, especially the non-sustainable utilization like overgrazing,extent of alkalization of Song-Nen grassland has been enlarged and the vegetation has been degraded seriously. The area of preponderant grass Leymus chinense （L. chinense） also reduced, the height of grass and the extent of closed canopy of grassland decreased, and the alkali spot with very little grass occurred in the grassland. PuccineUia 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 for certain years, making the plant population no longer the singularity population of P. tenuiflora. The mechanism about the vegetation of L. chinense succeeding 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 succession were not very clear. As to the cause of vegetation succession, there were many hypotheses, such as frequent fire and grazing, but nitrogen deposition had only recently been considered. 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 salt-alkali soil, the second was to quantify the changes of niche after the vegetation succession from P. tenuiflora to other kinds 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 salt-alkali 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 st

关 键 词：星星草 盐碱土 氮积累 土壤酶活性 生态位 植被演替 

分 类 号：S812[农业科学—草业科学]