| This paper,using the the natural spruce-fir mixed forest as the research object,which is located in Jingouling forest farm,Wangqing forestry burear,Jilin province.the gaps with the line investigation,three gaps are selecting through the (D/H) in order to study the characterstics of the mircroclimate.through the gap size and gap age to study the the characterstics regeneration in differents gaps, proposed some suggestions in the paper research in future which could be helped to the forest ecosystem management and other related researchs of forest science.Main conclusions of this paper were as following:The gaps area were most 40-80 squate meters in spruce-fir mixed stand,and the age of gaps were 10～30years,the gaps cause the cutting,made of 1～4 trees.The microclimate(light,temperature, soil temperature,air humidity) of gaps have the temporal and spatial differences,meanwhile,light play the most important in microclimate,and have the significant positive correlation with the gap area.The maximum light intensity not occurred at the center of gaps but the near center of the gaps. The highest light intensity was nearby the center for gap1, and appearance time was 11:-13:00; But the highest light intensity was at northeast sites nearby the center and at north sites nearby the center respectively for gap2 and gap3, and their appearance time was 13:00-15:00 and 11:00-13:00 respectively; The light intensity has different changes all the daytime, litte effect in morning and afternoon, And there were significant differences around at noon (P<0.05)The air temperature and soil temperature were higher in gaps than in non-gaps,and both the air and soil temperature exhibited single peak changing tendency in center of gaps. The maximum temperatures occurred at different time in the gaps. The highest air temperature and soil temperature(28.9℃, 25.4℃;26.8℃,24.1℃) was at northeast sites nearby the center and the center respectively for gapl and gap2, and their appearance time was 13:00-15:00, But the highest air temperature and soil temperature (24.1℃;17.8℃) was the center and at northeast sites nearby the center for gap3, and their appearance time was 11:00-13:00 and 7:00-11:00 respectively.The best regeneration gap area was occurred at 40 to 60 square meters,the maximum of seedling regeneration was 15248 N/hm2.The better seedling diameter occurred at150 to 250 square meters,meanwhile,the better seedling height occurred at 60 to 80 square meters,both the seedling diameter and seedling height in gaps more better than in non-gaos,and the richness and diversity was more than in non-gaps,the most impoutant regeneration speciies was fir in gaps.The age of gap that have more influent in gap regeneration,with increasing age gap regeneration density decreased gradually,gradually increasing the proportion of conifers,broadleaf trees declined.The seedlings was no significant difference in different points of gap,mainly distributed clustering,Compared two survey results between 2005 and 2010,the regeneration density decreased,seeling diameter growth and seedling height growth were growing well,the competition of seedlings will be more and more.
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