遮荫对紫椴苗木生长及光合特性影响研究

Shading impacts on seedling growth and photosynthetic characteristics of Tilia amurensis

通过对紫椴苗木进行人工遮荫处理,进行相对照度为70%、40%、30%、10%及全日照条件下的生长及光合特性分析。结果表明:在70%光照条件下苗木的高、地径及平均单株生物量最大,1 a、2 a生苗高分别比对照区提高20.0%和22.6%;2 a生地径达到1.9 cm,与其它试验区差异显著。相对照度10%、40%、70%及全日照的苗木其光饱和点(LSP)分别为400、800、900、800μmol.m-2.s-1。净光合速率(Pn)以相对照度70%试验区为最高,最大净光合速率达到9.28μmol.m-2.s-1,与其它试验区差异明显,10%试验区净光合速率(Pn)最低,40%与全日照试验区间差异不明显。

Effects of diferent sunlight intensity(70%,40%,30%,10% and full-sunlight) on seedling growth and photosynthetic characteristics of Tilia amurensis were studied.The results showed that: The height,ground diameter and average individual volume were all the biggest under 70% sunlight,height growth of 1-2 yr-old seedlings increased by 20.0% and 22.6% compared with control area,respectively;Ground diameter of 2-yr-old reached 1.9 cm,with significant differences to other trial areas.The light saturation point(LSP) of each sunlight intensity were 400,800,900 and 800 μmol·m-2·s-1,respectively.Net photosynthetic rate(Pn) of 70% sunlight was the highest,reached 9.28 μmol·m-2·s1,with significant differences to other trial areas,the lowest Pn appeared in 10% sunlight,and in 40% sunlight area was no significant difference to full-sunlight area.