吉兰泰盐湖不同林龄人工梭梭林的枝系构型特征

Characteristics of branch architecture of artificial Haloxylon ammodendron forests in different ages in Jilantai Salt Lake

植物生长构型特征是对其生境的适应表现,为了探究内蒙古吉兰泰盐湖人工林的枝系构型特征,以吉兰泰盐湖区人工种植的梭梭林为研究对象,选择5种林龄(2、5、10、15和30 a)进行样地设置,调查分析不同林龄下梭梭林表型生长特征及枝系构型的变化特征。结果表明:梭梭林的株高、冠幅、基径、各级枝长的变化表现为随林龄增大而显著增大的趋势(P<0.05);5种林龄梭梭林分支角度随着枝级的增加而减小,分枝角度表现为越靠近植株主体越大,且随林龄的增加其承载能力增强;不同林龄人工梭梭林的整体构型表现出一定的可塑性,林龄为2、5、10和15 a的梭梭整体外观呈“高瘦形”灌木;林龄为30 a梭梭林整体外观呈“矮胖形”灌木。综上,吉兰泰盐湖区域防护林梭梭林在5 a以下林龄期以纵向空间资源探索为主,在30 a林龄以横向空间资源探索为主。研究结果为林木的生态适应性和进化机制及防风固沙林的选择和优化配置提供理论依据。

[Background]The characteristics of plant growth architecture are the performance of adaptation to its habitat.In order to explore whether the plant architecture of Haloxylon ammodendron forests will change with the increase of growth years in the process of salt lake protection.To study the clade configuration characteristics of H.ammodendron forests of different ages,and to understand the relationship between the configuration characteristics and the environment,so as to further understand the population dynamics and ecological adaptability of H.ammodendron.It provides a theoretical basis for the ecological adaptability and evolution mechanism of H.ammodendron forests and the selection and optimal allocation of windbreak and sand-fixing forests.[Methods]H.ammodendron forests planted artificially in the Jilantai Salt Lake area were selected as the research object,and five forest ages(2,5,10,15 and 30 years)were selected for plot setting.The phenotypic growth characteristics and clade configuration changes of H.ammodendron under different stand ages were investigated and analyzed.[Results]The changes of plant height,crown width,base diameter and branch length of H.ammodendron showed a trend of increasing significantly with the increase of forest age(P<0.05).The growth ability of big forest age of H.ammodendron was stronger,which was beneficial to the regeneration of H.ammodendron population.The branching angle of H.ammodendron of five forest ages decreased with the increase of branch level.The branch angle showed that the closer it was to the main stem of the H.ammodendron,the larger the branch angle,and its carrying capacity increased with the increase of forest ages.The overall configuration of H.ammodendron with different forest ages was flexible.The overall appearance of H.ammodendron at 2,5,10 and 15 years was“tall and thin”and with forest ages of 30 ages was“low and fat”.[Conclusions]The protection forest of H.ammodendron in the Jilantai Salt Lake area was dominated by vertical spatial resource exploration in the forest age of less than 5 years,and the horizontal spatial resource exploration was mainly used in the forest age of 30 years.Afforestation pattern allocation can be optimized according to different afforestation ages and vegetation characteristics in arid and semi-arid areas.