光照及地面覆盖物对水青树种子萌发和幼苗初期生长的影响  

Effects of light and ground cover on seed germination and seedling initial growth of Tetracentron sinense

作　　者：许宁[1,2] 憨宏艳 甘小洪[1,2] 

机构地区：[1]西华师范大学西南野生动植物资源保护教育部重点实验室 [2]西华师范大学生命科学学院

出　　处：《植物资源与环境学报》2015年第3期85-93,共9页Journal of Plant Resources and Environment

基　　金：国家自然科学基金资助项目(31370637);四川省教育厅自然科学重点项目(12ZA169)

摘　　要：通过模拟野外自然环境,设置强光、中度光照和弱光(分别相当于自然光照强度的100%、50%和10%)3种光照条件以及无覆盖物、覆盖灌草丛及覆盖灌草丛和枯落物3类苗床,研究了光照及地面覆盖物对水青树(Tetracentron sinense Oliv.)种子萌发率、幼苗存活率及初期生长状况的影响。结果显示:在不同光照条件下,水青树种子的萌发率均为在无覆盖物的苗床中最高、在覆盖灌草丛的苗床中最低,其中,中度光照条件下在无覆盖物的苗床中种子萌发率最高。各处理组1月龄幼苗的存活率总体上高于2月龄幼苗,且在不同的苗床中弱光条件下1月龄幼苗存活率均最高;总体上,弱光条件下覆盖灌草丛的苗床最宜于水青树1月龄幼苗存活。随光照强度减弱,在无覆盖物及覆盖灌草丛的苗床中幼苗的株高和主根长度均逐渐降低,而在覆盖灌草丛和枯落物的苗床中则呈波动趋势,但总体上各处理组幼苗的株高和主根长度无显著差异。随光照强度变化或苗床覆盖程度的变化,幼苗的侧根数,叶面积,根、茎和叶片的干质量以及总干质量均呈现不同的变化规律;强光条件下,在覆盖灌草丛的苗床中幼苗的根干质量均最大;中度光照条件下,在覆盖灌草丛的苗床中幼苗的侧根数、叶面积、叶片干质量及总干质量均最大;中度光照和弱光条件下在无覆盖物的苗床中幼苗的茎干质量最大。综合分析结果表明:水青树种子萌发需要一定的光照条件且地面的枯落物和灌草丛会阻碍其种子萌发,而其幼苗定居阶段则需要适度荫蔽且地面覆盖灌草丛有利于其幼苗存活,因此,林窗或林缘更适合于水青树的自然更新;此外,在水青树的就地保护过程中应根据其生活史的不同阶段采取不同的栽培措施。By means of simulating wild natural environment, three kinds of light conditions with strong, middle and weak lights （being equivalent to 100%, 50% and 10% of natural light intensity, respectively） and three types of seedbeds with no cover, covering shrub-grass and covering shrub-grass and litter were set up. And effects of light and ground cover on seed germination rate, seedling survival rate and initial growth status of Tetracentron sinense Oliv. were investigated. The results show that under different light conditions, seed germination rate of T. sinense is the highest in no cover seedbed and the lowest in covering shrub-grass seedbed, in which, that is the highest in no cover seedbed under middle light condition. Survival rate of seedling with one month age in every treatment group is generally higher than that of seedling with two month age, and among different seedbeds, survival rate of seedling with one month age is the highest under weak light condition. In general, under weak light condition, covering shrub-grass seedbed is the most suitable for survive of T. sinense seedling with one month age. With

关 键 词：水青树 光照 地面覆盖物 种子萌发 幼苗生长 存活率 

分 类 号：Q948.11[生物学—植物学] X37[环境科学与工程—环境工程]