Study On Succession Of Plant Community In Air-seeding Area Of Hunshandake Sandland

In this study,the vegetation in the aerial area of 18 years(1999-2015)was investigated for four consecutive years in the aerial area of Hunshandake sand.The results showed that the abundance,coverage,height and biomass of the four kinds of aerial seed species of Hedysarum laeve,Artemisia sphaerocephala,Astragalus adsurgens'Shadawang' and Ulmus pumila var.sabulosa were analyzed by using space instead of time.And Community structure,life type and diversity were also analyzed.The stability of the community in the succession process was discussed with the restoring force comprehensive index,photosynthetic functional type and community structure variability.The aim was to reveal the vegetation restoration And provide the basis for maintaining the stability of vegetation in the aerial area.Research indicates:1.The quantitative characteristics of four kinds of aerial seed populations showed significant differences in the succession process of aerial area in Hunshandake sandy land.In the succession process,except during the year,the height of Hedysarum laeve was between 61 and 118cm,the height of Artemisia sphaerocephala was between 53 and 81.33cm,the height of Astragalus adsurgens 'Shadawang' was between 25.89 and 78.33cm;Abundance,coverage and biomass of Hedysarum laeve reached the peak of 9.84million plants/hm2,68.33%and 4222.78g/m2 respectively,and then decreased,but the population could be maintained for a long time.The results showed that the abundance of Artemisia sphaerocephala and Astragalus adsurgens 'Shadawang' were decreasing year by year trend,the coverage and biomass of Artemisia sphaerocephala reached the peak values of 10.17%and 126.38g/m2 in the succession 3a,and the coverage and biomass Astragalus adsurgens 'Shadawang' peak were 12.67%and 37.0g/m2 respectively.In the succession 11a,10a from the community completely decay out;the coverage,height,biomass of Ulmus pumila var.sabulosa showed a slow increase in volatility,abundance of Ulmus pumila var.sabulosa showed an increasing in the succession 1 to 5 years trend and in the succession 6 to 18 years,basic Constant,the dominant role of the community gradually increased.2.In the succession 1 to 8 years vegetation coverage were from 15%to 77%,9 to 18 years gradually stabilized,about 57%.In the succession process,the succession of 1 to 7 years,community species were composition of one or two years old herbaceous plants,succession 8 to 18 years perennial herb mainly with the succession time.With the extension of the succession time,the species composition is more complicated and diversified,which is more conducive to the stability of the community.Partrick Richness Index succession 1 to 9 years,were from 12 to 55;after the succession 10 it was the maintenance of more than 30.In the succession 1 to 10 years Shannon-Wiener diversity index were from 2.42 to 3.92;succession 11a,the range of variation of 3.14-3.90.In the process of succession,the Pielou evenness index fluctuated significantly,but the population showed a slow increasing trend,reaching 1.17 in the succession.3.Succession 2a,the resilience of the comprehensive index of up to 2.87,succession 3-11a was decreasing trend;which succession 9-11 a,affected by community competition,restoring force comprehensive index is less than 1;after the succession 12a,The resilience of the community was greater than 1,and the resilience of the community was higher.C3 plant species in the succession 1-10a came from 6 to 35,succession 11-18a tends to be constant trend;C4 plant species in the succession 1-12a came from 2 to 13,succession 13-18a tends to Constant;C4/C3 ratio from the overall succession process,showing a decreasing trend.The C4 plant population played a certain role in the stabilization of the sand dunes after the succession of the aerial sowing,and the C3 plants had a greater significance for the stability of the later succession.In the process of succession,the successional time is similar to the variation coefficient between the communities,which is relatively small,and the "gradient" substitution among species in the community reflects the relatively stable development of the community to a certain extent.