N添加对白羊草生长及种群特征的影响  

Effects of Nitrogen Additions on Growth and Propagation of Bothriochloa Ischaemum Population

作　　者：李文达[1] 王国梁[1,2] 刘国彬[1,2] 由政 邱甜甜[1] 吕凤莲[1] 李盼盼[1] 

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100

出　　处：《水土保持通报》2016年第1期174-178,共5页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目"土壤有效N升高对白羊草群落特征及土壤侵蚀过程的影响机制"(D011004);国家"十二五"科技支撑课题(2015BAC01B03)

摘　　要：[目的]分析N添加对白羊草(Bothriochloa ischaemum)种群特征及繁殖策略的影响,为评估氮沉降的生态影响提供科学依据。[方法]以黄土高原地带性优势种群白羊草为对象,设置对照CK〔0g/(m^2·a)〕,低氮〔2.5g/(m^2·a)〕,中氮〔5.0g/(m^2·a)〕和高氮〔10.0g/(m^2·a)〕4个N添加水平,研究了为期两年的N添加对白羊草种群特征及繁殖策略的影响。[结果](1)N添加显著增加了白羊草种群的密度、株高和生物量,其中中氮处理下种群生物量达到最大;(2)N添加改变了白羊草生物量的分配策略,根冠比随N添加量增大而减小,支持功能平衡假说;(3)N添加促进了白羊草种群的营养繁殖和有性繁殖,提高了其繁殖竞争能力。[结论]适度N沉降或N添加〔<5g/(m^2·a)〕促进了白羊草种群的生长和发育,有利于白羊草种群水土保持等生态功能的发挥。[Objective]The objective of this study is to analyze the influences of N addition on population characteristics and reproduction strategies of Bothriochloa ischaemum population in order to assess the impact of N deposition on the ecological environment.[Methods]This study was conducted to investigate the responses of population characteristics and reproduction strategies of B.ischaemum population to N addition based on four N addition treatments,including control CK〔0g/（m^2·a）〕,low nitrogen〔2.5g/（m^2·a）〕,middle nitrogen〔5.0g/（m^2·a）〕and high nitrogen〔10.0g/（m^2·a）〕for two years.[Results]（1）The N addition significantly increased the height and biomass of B.ischaemum population,population biomass reached the maximum with middle nitrogen treatment.（2）N addition had changed the nutrient allocation strategies of B.ischaemum.Root-shoot ratio decreased with the increments of N addition.（3）N addition promoted sexual reproduction and vegetative propagation of B.ischaemum population,enabled its high ability of breeding and competition.[Conclusion]Moderate N sedimentation or N addition 〔〈5g/（m^2·a）〕can promote the growth and development of B.ischaemum population,and improve its ecological function in soil and water conservation.

关 键 词：N添加 种群特征 生物量 分配策略 黄土高原 

分 类 号：S543.9[农业科学—作物学]