Study On Seed Regeneration Of Larix Gmelini In Inner Mongolia Daxing'anling Mountain

We chose four kinds of cuts the forest lands in this dissertation.Based on field investigation and physical separation,the several life history stages of the Larix Gmelini from seed dispersal to seeds germination were involved,and all data obtained about seed rain,seed bank and seeding bank were analyzed.The result showed:①the Larix Gmelini of average seed rain intensity was 20.50 seed per m~2,in which the viable seed was 10.37%,and the seed rain pattern mainly showed level distribution which was uneven;②Soil seed reserves were different in the forest lands of spring because different growth conditions in four kinds of cuts the forest lands.Among its four forest types,the order of Total Soil Seed Density(TSSD)was jamming forest>virgin forest>gradual cutting forest >clear cutting forest;③The clear cutting forest of mean Vital Soil Seed Density(VSSD)was zero,other three forest types of VSSD are smaller than 2%,98% of intact Larix gmelini seeds was barrenness with extremely low vitality.It can thus be postulated that soil seed bank is of seasonal transient type;④The seed distribution patterns in study area,controlled by seeding wood distribution pattern,present some degrees of clustering trends.Almost all of the seeds in the seed rain distributed on the litter layer,and the viable seed density in soil seed bank decreased with the increasing of soil depth ;⑤After the seed germination , there were fewer seedlings in the Daxing'anling,and there was to have the largest number only 24 strain perm~2 in the plots.The invert percentage of seeds to seedling was 0.047～0.39% under the natural condition.Litter was the most primary factors of micro-habitat affecting regeneration of one-year seedling.At the same time,the litter promoted regeneration.The most important factor of micro-habitat affecting survival of two-year seedling was still litter,but the influence of litter was un-favorable.