| The natural forest in the Tianshan Mountains is an evergreen coniferous forest community mainly composed of Picea schrenkiana var.tianschanica,a remnant of Tertiary forest plants.Based on the Tianshan spruce 1 a seedlings as the research object,based on breaking the root the intertwining layer,add biochar soil and soil temperature carbonization live experiment,three kinds of microenvironment jamming modes using seedlings in situ observation,data collection methods,such as whole plant harvest and probability distribution fitting,survival analysis,variance analysis and statistical analysis method,through the analysis of the occurrence process,survival dynamics and functional traits of the direct seeding seedlings of Tianshan spruce and the natural regeneration seedlings without anthropogenic disturbance in the microhabitat under different methods of anthropogenic disturbance,the purpose of this study was to explore the methods of anthropogenic disturbance in the microhabitat for the successful development of Tianshan spruce seedlings.The main research results are as follows:Under three anthropogenic disturbances methods,namely root disarray breaking,topsoil biochar addition and topsoil high temperature carbonization,the seedling occurrence time of Tianshan spruce followed Weibull distribution,and the seedling occurrence process could be divided into three stages: initial stage,peak stage and end stage.The duration of the early stage was 6,15 and 13 days,and the duration of the peak stage was 20,38 and 32 days,respectively,and the seedlings entered the end stage on the 27 th,54th and 47 th day.The number of seedling daily occurrence and cumulative occurrence per unit area were the largest under the microhabitat disturbance caused by topsoil biochar addition.The survival time of seedlings of Tianshan spruce occurred at different stages in the first growth season was significantly different(P<0.01).The death risk rates of seedlings in the peak and late stages of occurrence were 82% and 112.63% higher than those in the early stages of occurrence,respectively.Compared with the natural regeneration without anthropogenic disturbance,the three kinds of microhabitat anthropogenic disturbances can reduce the mortality of Tianshan spruce seedlings in the first growth season,and the addition of biochar to topsoil and the breaking of root mat can improve the survival rate of the 1-year-old seedlings of Tianshan spruce after overwintering,which has reached a significant level(P<0.05),The survival rate and survival number of seedlings after overwintering were the highest under the interference mode of adding biochar to topsoil.There were significant differences in the functional traits of 1-a-old live-streaming seedlings of three kinds of microhabitat disturbed by anthropogenic disturbance compared with those of natural regeneration seedlings without anthropogenic disturbance in microhabitat(P<0.05),among which: The specific stem density,leaf length-width ratio and leaf tissue density were the lowest under the disturbance of breaking the root mat,which were(0.48±0.02)g·cm-3,(23.58±0.60)cm·cm-1 and(0.26±0.01)g·cm-3,respectively.Under the interference of topsoil biochar addition,the specific root area,specific root length,specific stem length,rhizome length ratio,rhizome dry matter ratio,leaf length and specific leaf area reached the maximum.They are(313.54±11.27)cm2·g-1,(2140.44±39.46)cm·g-1,(802.00±17.10)cm·g-1,(6.63±0.18)cm·cm-1,(2.34±0.08)g·g-1,(1.83±0.04)cm and(317.83±10.26)cm2·g-1;Under the condition of high temperature carbonization interference,the average root length was the highest(16.85±0.23)cm,and the root tissue density was the lowest(0.29±0.01)g·cm-3.The addition of biochar in topsoil was a kind of anthropogenic disturbance to microhabitat,which was conducive to the development of 1 a seedling of Tianshan spruce. |
PDF Full Text Request