摘要
采用Levins生态位指数、Pianka生态位重叠指数和物种多样性指数,分析草甸草原区主要植物种群生态位对封育年限的响应特征。结果表明:退化草地实施封育措施后,群落中主要植物种群生态位宽度发生变化,未封育(对照区)样地以多年生草本植物蒲公英生态位宽度最大;封育年限为4和13年时,生态位宽度最大的物种均为展枝唐松草;封育年限为5、6、8和10年时,生态位宽度最高的物种依次是羊草、麻花头、囊花鸢尾和贝加尔针茅;退化草地实施封育后,物种间生态位重叠指数值集中在0.6~0.9,而未封育样地物种生态位重叠指数值在0.0~0.3;随着封育年限的增加,生态位重叠指数总平均值表现出先增加后降低的变化趋势,其中未封育(对照区)样地主要植物种群生态位重叠指数总平均值最低,封育5年时,主要植物种群生态位重叠指数总平均值最大,为0.68;封育草地的主要植物种群的生态位重叠指数平均值较未封育(对照区)样地增加了40.76%~93.68%;封育年限为5年时,Shannon-Wiener多样性指数、Simpson多样性指数和Margalef丰富度指数、Pielou均匀度指数最大,分别比未封育(对照区)增加了45.46%、16.51%、45.80%和23.38%。封育后,群落多样性、丰富度和均匀度显著增加,并且植物种间竞争加剧,但在封育5年后,随着封育年限的增加,多样性、丰富度以及均匀度逐渐降低,导致生态位分化,种间竞争减缓,群落趋于稳定。因此,从物种多样性角度出发,该区封育时间不宜过长,在封育5年后,可采取适当利用,保护群落多样性。
In this study,we determined the responses of main plant populations in the meadow steppe area to enclosure for various periods of time.Levin’s niche index,Pianka’s niche overlap index,and species diversity indexes were calculated to analyze the niche response characteristics of the main plant populations.The results showed that the niche breadth of main plant populations in degraded grassland changed after enclosure.The largest niche breadth of the perennial herb Taraxacum mongolicum was in the unenclosed(control)plot.At 4 and 13 years of enclosure,pinegrass had the largest niche breadth.At 5,6,8,and 10 years of enclosure,the species with the largest niche breadth were Leymus chinensis,Serratula komarovii,Iris ventricosa,and Stipa baicalensis.After the enclosure of degraded grassland,the niche overlap index between species was concentrated in the range of 0.6-0.9,while the niche overlap index between species in the unenclosed plot was in the range of 0.0-0.3.As the period of enclosure increased,the total average value of the niche overlap index tended to first increase and then decrease.The lowest total average value of the niche overlap index of main plant populations was in the unenclosed(control)plot.The highest total average value of the niche overlap index of the main plant populations was 0.68 at 5 years of enclosure.The total average value of the niche overlap index of main plant populations in enclosed grassland was 40.76%-93.68%higher than that in unenclosed grassland.The highest values of the Shannon-Wiener diversity index,Simpson’s diversity index,Margalef’s richness index,Pielou’s evenness index were obtained at 5 years of enclosure,and were 45.46%,16.51%,45.80%and 23.38%higher than their respective values in the control(unenclosed)site.Enclosure significantly increased community diversity,richness,and evenness,and intensified interspecific competition.However,as the period of enclosure extended beyond 5 years,the diversity,richness and uniformity gradually decreased.This led to niche differentiation,the slowing of inter-species competition,and stabilization of the community.Therefore,from the perspective of species diversity alone,the enclosure time should not be too long.After 5 years of enclosure,appropriate measures may be implemented to protect community diversity.
作者
聂莹莹
陈金强
辛晓平
徐丽君
杨桂霞
王旭
NIE Ying-ying;CHEN Jin-qiang;XIN Xiao-ping;XU Li-jun;YANG Gui-xia;WANG Xu(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Hulun Buir Grassland Ecosystem Research Station,Beijing 100081,China)
出处
《草业学报》
CSCD
北大核心
2021年第10期15-25,共11页
Acta Prataculturae Sinica
基金
国家重点研发计划项目草地碳收支监测评估技术合作研究(2017YFE0104500)
农田草地生态质量监测技术集成与应用示范(2017YFC0503805)
呼伦贝尔退化草甸草原综合治理技术与模式(2016YFC0500603)
国家自然基金开垦对温性草甸草原土壤氮转化与平衡的影响微生物学机制(41703081)资助。
