Effects Of Altitude On Seed Germination And Seedling Growth Of Platycladus Orientalis In Mountain Tai

Platycladus orientalis is one of the main constructive species in the forest of Mountain Tai.In order to explore the adaptive strategies of Platycladus orientalis seedlings,seeds of the mother trees at different altitudes(200m,300m,500m,800m and 1000m)were collected and the seed germination,biomass allocation and root characteristics of seedlings were studied by pots experiments.The results showed altitude had a significant influence on the germination rate.The maximum value appeared at 500m and 800m,and the minimum appeared at 1000m.On the biomass allocation,the seedling biomass and root mass ratio increased with the increase of altitude,while the specific leaf area and leaf area ratio showed a wavy increase..However,the root characteristics of seedlings decreased in a wave shape with the increase of altitude..With the development of seedlings,the influence of altitude on the morphological characteristics of seedlings gradually decreased.Correlation analysis showed that the seedling biomass was positively related to leaf biomass at 210 days,and negatively correlated with stem biomass ratio,but there was no significant correlation at 360 days.There was a significant positive correlation between aboveground biomass and belowground biomass,indicating that there was a significant correlation between them.At the same time,along with the development of individual seedlings,effects of mother trees on seedlings growth decreased gradually.