Study On The Pattern Of Natural Regeneration Of Quercus Mongolica And Populus Davidana Populations In Saihanwula’s Deciduous Broad-Leaved Forest

In this paper,the populations of Quercus mongolica and Populus davidana populations in the Saihanwula National Nature Reserve were used to study the age structure and dynamics of the population,the spatial distribution pattern of the population,the space of different ages distribution pattern and interspecific association were studied.Two plots were set up with the size of 50m × 50m.The individuals were located and the height and DBH were measured.The tree area was divided into two groups.Trees and seedlings for the size of the division,drawing static life table,the use of ADE4 positioning data for the pattern analysis.The results show:(1)In the range of this study,the populations of Quercus mongolica and Populus davidana were growing,and the growth of Quercus mongolica was higher than that of Populus davidana,and the two populations’ regeneration were normal.(2)In this study,the populations of Quercus mongolica and Populus davidana were clustered on a small scale(0-22 m,where 0-16 m was more typical)and were randomly distributed(22-25 m).The aggregation intensity increases with the scale,and reaches a certain peak and decreases with the increase of the scale.Quercus mongolica and Populus davidana were clustered on the small scale(0-18m,0-7m),and were distributed at larger scale(18-25m).The young trees were distributed on the small scale(0-17m),(17-25m)were randomly distributed or evenly distributed.The spheroids were clustered at all scales(0-25m).(3)There was a significant negative correlation between grade Ⅰ and grade Ⅱat 0-7m,grade Ⅲ and grade Ⅳat 5-25 m,and the correlation between other grades was not significant.But there was a significant negative correlation between grade Ⅱand grade Ⅲ at 2-25 m.The negative correlation between Quercus mongolica and Populus davidana population was close to or even significant at 0-25m scale.With the increase of scale,the negative correlation increased,and the two populations had the effect of suppressing growth.There was a significant negative correlation between the seedlings of Quercus mongolica and Populus davidana on the 8-25m scale,among which 8-12m was the most significant,and the correlation among young trees was not significant.