两个喀斯特森林树种幼苗对不同光照的生态适应性

The Effect of Different Light Intensity on Seedling Ecological Adaptability of Two Karst Tree Species

以构树、青檀两种喀斯特森林树种幼树为材料进行盆栽试验,分别用100%、40%、20%、10%的光照强度处理50 d。结果表明:构树和青檀幼苗在相对光照强度为100%时株高达到最大,而在相对光强为40%时地径达最大。随着光照强度的降低,青檀的叶绿素含量、SOD活性和可溶性糖均增加,质膜透性和丙二醛含量则下降;构树的叶绿素含量、SOD活性和可溶性糖均下降,质膜透性和丙二醛含量则增加;并且在透光率40%处理条件下光合作用和蒸腾作用最大,生长也较好。表明,构树幼苗适应强光下生长,青檀幼苗适应轻度遮阴环境。

The pot experiment of Broussonetiap papyrifer and Pteroceltis tatarinowii Maxim seedlings was conducted under different light intensity for 50 d to study the effect on their ecological adaptability. The results showed that the seedling plant height and stem diameter of two tested species was up to maximum when the relative light intensity was 100% and 40% respectively. The chlorophyll content, SOD activity and soluble sugar content of P. tatarinowii Maxim＇s seedlings increased and its PM and MDA decreased with reduction of light intensity respectively. The chlorophyll content, SOD activity and soluble sugar content of B. papyrifer seedlings decreased and its PM and MDA increased with reduction of light intensity respectively, and its net photosynthesis rate and transpiration rate was up to maximum under 40% light intensity. The results indicates that B. papyrifer seedlings can grow under the strong light and P. tatarinowii Maxim＇s seedlings can grow under the mildly shade condition.