光强对细叶云南松幼苗成活率及生长的影响

Effects of Light Intensity on Seedling Survival Rate and Growth of Pinus yunnanensis var. tenuifolia

通过搭建一层遮荫(50.3%NS)、二层遮荫(15%NS)、三层遮荫(4.2%NS)以及自然光照(100%NS)分别设置4种不同的光强,研究细叶云南松幼苗一月生苗与半年生苗成活率及根系生长发育在不同光强下的特征。结果表明,细叶云南松一月生和半年生苗期生长的存活率、地径增长量在100%光照下最大,且随遮荫强度增加而逐渐减小;在50.3%光照下,细叶云南松一月生和半年生苗木的苗高增长量达到最大。不同光强对细叶云南松根系生长有显著影响,幼苗的根系总长度、总根尖数、根系总表面积和根系总体积均随光照强度减弱而降低,全光照有利于细叶云南松根系的生长发育。

A layer of shading （ 50.3 % NS）, two layer of shading （ 15 % NS）, three layer of shading （ 4.2 % NS） and natural light （ 100 % NS） were set up to 4 different light intensity, in order to research the seedling survival rate and root growth of Pinus yunnanensis var. tenuifo- lia of one-manth seedling and half a year seedling and their response characteristics under different light intensity. The results showed that the seeding growth of one-month and half a year of Pinus yunnanensis var. tennifolia, survival rate, diameter growth in 100 % light reached maximum and gradually decreased with increasing shading intensity; 50.3 % in the light of Pinus yunnanensis var. tenuifolia from one- month seedling and half a year seedling,the height growth reached the maximum. The different light intensity had significant effects on the root growth of Pinus yunnanensis var. tenuifolia, total root length, total root number, total root surface area and root volume of seedlings which decreased with the light intensity decreased. Natural light （ 100 % NS） were beneficial to the root growth and development of Pinus yunnanensis var. tenuifolia.