| The Taishan forest community is a typical representative of vegetation in North China,and the deciduous broad-leaved forest represented by deciduous oaks is the zonal vegetation of Mount Tai.As a building tree species in this area,the natural regeneration quality of the oak forest is of great significance to the construction of Mount Tai’s ecological civilization.In order to study the natural regeneration characteristics of the pure forest regeneration seedlings（saplings）of Quercus quercus,evaluate its natural regeneration quality,and explore the main influencing factors of its regeneration status,this paper takes the pure forest of Mount Taishan Quercus as the research object,using a combination of field data survey,fixed-point sampling and indoor processing and analysis.The quality of natural regeneration,species diversity of regeneration layer,spatial distribution pattern of regeneration seedlings,and the main influencing factors of natural regeneration of Quercus quercus seedlings（saplings）were studied.In order to provide a scientific basis for in-depth discussion of artificial promotion of natural regeneration and near-natural management.The main findings are as follows:（1）The total regeneration density of Quercus taerensis under the forest was 7084plants·hm-2,of which the densities of renewed seedlings,saplings and mature trees were 3643plants·hm-2,1207 plants·hm-2 and 94 plants·hm-2,respectively.The density of regenerated seedlings was significantly higher than that of regenerated saplings and mature trees.The standard deviation of the regeneration density among the plots is large.The maximum regeneration density between the plots was 14363 plants·hm-2,and the minimum was only1175 plants·hm-2.The distribution of newer seedlings was uneven and tended to be clustered.Among the 18 survey plots,all plots were updated,and only one plot was poorly updated.The update quality evaluation of the rest of the plots is medium or above,accounting for 93.3%of the total plot area,of which 73.11%are well-updated plots.（2）The richness index of the two layers of shrub and grass in the survey plot significantly affected the regeneration status of the understory,and the appropriate richness of the shrub and grass was beneficial to the growth of the regeneration seedlings;the species richness index（SR）、Shannon-wiener index（H’）and the probability of interspecific encounter（PIE）of the herb layer was significantly higher than that of the shrub layer.The regenerated seedlings were all clustered under the three sampling scales,and the aggregation intensity was the largest at the 20m×20m sampling scale.Meanwhile,the regeneration seedlings of each regeneration level were also clustered under the three sampling scales.The base diameter of the renewed seedlings（saplings）of Quercus quercus is mostly between 0and 0.6 cm,and the height grade is mostly between 0 and 40 cm.The larger the base diameter and height grade,the less the number of renewed seedlings.（3）The content of organic matter and available potassium in soil can affect the quality of natural regeneration,and appropriate amount of organic matter and available potassium can promote regeneration.The thickness of the undecomposed layer and the uniformity of each layer of the understory litter significantly affect the natural regeneration.The total thickness of the litter has a significant negative correlation with the density of grade III saplings and the regeneration index.There was also a significant negative correlation between the thickness of the undecomposed layer and the density of grade V trees,indicating that the thicker the understory litter,the more unfavorable it is for regeneration.（4）The natural regeneration of Quercus japonica forest in Mount Tai is also affected by factors such as altitude,oak density,average diameter at breast height,stand canopy density,illuminance and herb cover.The total regeneration density is the largest in the range of330-430m above sea level,which is the main factor affecting the regeneration;the density of Quercus chinensis is a direct factor affecting the natural regeneration.,the higher density of oak forest promotes the natural regeneration of understory;the average diameter at breast height,stand canopy density,light intensity and herb cover are indirect influencing factors. |
PDF Full Text Request