施氮对空心莲子草(Alternanthera philoxeroides)和莲子草(Alternanthera sessilis)种间关系的影响  

Effects of nitrogen addition on interspecific competition between Alternanthera philoxeroides and Alternanthera sessilis

作　　者：周建[1] 李红丽[1] 罗芳丽[1] 黄文军[2] 张明祥[1] 于飞海[1] 

机构地区：[1]北京林业大学自然保护区学院,北京100083 [2]四川省林业科学研究院,成都610081

出　　处：《生态学报》2015年第24期8258-8267,共10页Acta Ecologica Sinica

基　　金：中央高校基本科研业务费专项资金资助(TD-JC-2013-1);高等学校博士学科点专项科研基金新教师类资助课题(20120014120001);国家自然科学基金项目(31200313,31200314)

摘　　要：自然界的氮素释放总是呈现出空间和时间上的异质性,但关于异质性氮释放对于入侵植物和本地植物种间关系影响的研究相对较少。将入侵植物空心莲子草(Alternanthera philoxeroides)和同属本地植物莲子草(Alternanthera sessilis)分别进行单种种植(12株,无种间竞争)和混种种植(每种6株,有种间竞争),模拟大气氮湿沉降设置由两种不同施氮总量(15g N m^(-2)a^(-1)和30g N m^(-2)a^(-1))和两种不同施氮频率(每5天1次和每15天1次)交叉组成的4种施氮处理,并以不施氮为对照。施氮总量的增加显著促进了两种植物的生长,但对两种植物的种间竞争关系没有显著影响。施氮频率对两种植物的生长以及种间竞争关系都没有显著影响。两种植物在面对竞争时表现出不同的生物量分配策略,空心莲子草将更多的生物量分配到茎,而莲子草将更多的生物量分配到根。在全球变化的背景下,大气氮湿沉降可能会改变两种植物的种群结构和动态,但可能对这两种植物的种间关系影响较小。Nitrogen （N） is one of the most important soil nutrients for plants, and the amount and frequency of N release in soils is heterogeneous. Many studies have tbeused on the effe, cts of heterogeneous N addition on a single plant speeies, but little is kno~.n about the effects or N amount and short-term N pulse on interspecifie competition between invasive and mitive plant species. A replacement series experiment was condueted under greenhouse conditions to examine the effeets of N amount and frequency release on the growth and interspeeifie competition between an invasive wetland elonal plant, Alteruamhera philoxeroides （alligator weed） , which is native in South America but highly invasive in China, and its native congener Alteru,uthera sessilis （sessile joyweed）. Plant materials of A. philoxeroides and A. sessilis were collected from five locations in Xixi Wetlaud Park in Hangzhou, Zhejiang Provinee, China. Stem fragments of similar length （20 cm） , with a stem tip for each species, were grown in monoeulture （12 ramets in one eontainer, no interspecifie competition） and in mixture （six invasive plants with six native plants, with interspecifie competition） in live different N treatments： control （no N added）, low amount and high frequeney （a total of 15 g N m^-2 a^-1 added every 5 days）, low amount and low frequency （a total of 15 g N m^-2 a^-1 I added every 15 day＇s） , high amount and high frequency （a total of 30 g N m^-2 a^-1 added every 5 days） , amt high amount and low frequency （a total of 30 g N m^-2 a^-1 added every 15 days）. The results showed that N addition significantly increased tile growth of both A. philoxeroides and A. sessilis. No significant difference was observed between the control and treatments for the relative yield （yield of each species in mixture divided by yield in its monoculture） tor both species, indicating that N addition did not significantly affect the interspeeific competition between the two species. The probable reason is tha

关 键 词：氮沉降 克隆植物 种间竞争 入侵植物 本地植物 脉冲式施氮 相对产量 

分 类 号：S45[农业科学—植物保护]