植被和凋落物对水杉天然幼苗萌发的影响  

Effects of vegetation and litter on natural seedling germination of Metasequoia glyptostroboides

作　　者：徐来仙 姚兰 艾训儒 郭秋菊 刘本洲 向钦 XU Laixian;YAO Lan;AI Xunru;GUO Qiuju;LIU Benzhou;XIANG Qin(School of Forestry and Horticulture,Hubei Minzu University,Enshi,Hubei 445000,China;Lichuan Hongchun Forest Farm,Lichuan,Hubei 445400,China)

机构地区：[1]湖北民族大学林学园艺学院,湖北恩施445000 [2]利川市红椿林场,湖北利川445400

出　　处：《森林与环境学报》2022年第5期456-464,共9页Journal of Forest and Environment

基　　金：湖北省自然科学基金项目“水杉原生种群天然更新障碍机制研究”(2019CFB229)。

摘　　要：为查明水杉天然更新的关键障碍因素,探索促进水杉天然更新的有效途径,在野外原生境中选择5株水杉母树作为研究对象,以水杉母树为中心设置样圆,在样圆内采用不同林下处理方式(群落阻隔、林下活地被物阻隔、凋落物阻隔和无阻隔)进行分区试验,研究植被和凋落物对水杉天然更新的影响。结果表明:不同林下处理方式对水杉幼苗更新密度、存活率、苗高、地径、根长、叶片数量、叶面积、地上生物量和地下生物量有极显著影响(P<0.01);幼苗萌发生长指标均在无阻隔区达到最大值,再由高到低依次是凋落物阻隔区、林下活地被物阻隔区、群落阻隔区。水杉林下活地被物、凋落物和群落环境均是造成水杉天然更新困难的障碍因素,对水杉种子萌发和幼苗生长抑制程度的排序为:群落环境>林下活地被物>凋落物。水杉幼苗苗高的生长动态变化符合S型生长曲线(R~2≥0.893),4种处理方式的水杉幼苗更新密度均呈倒“V”形分布。无阻隔处理显著促进了水杉幼苗的天然更新,其存活率、苗高、地径、根长、叶片数量、叶面积、生长速率及生物量等指标均最高;今后在水杉种群保护和管理中,应适当清除林下活地被物和凋落物,为水杉种子萌发和幼苗生长提供适宜环境,促进水杉种群天然更新。To identify the key factors involved in hindering and effectively promoting the natural regeneration of Metasequoia glyptostroboides,five M.glyptostroboides mother trees in the original wild habitat were selected for this study.The sample circle was set with the M.glyptostroboides mother tree as the center.Different understory treatments(community barrier,understory living ground cover barrier,litter barrier,and non-barrier)were used to conduct the zoning experiment to study the effects of vegetation and litter on the natural regeneration of M.glyptostroboides.Different understory treatments were found to have significant effects on M.glyptostroboides seedling regeneration density,survival rate,height,base diameter,root length,leaf number,leaf area,aboveground biomass,and underground biomass(P<0.01).All seedling germination growth indicators reached their maximum values in the non-barrier area,followed by the litter barrier area,understory living ground cover barrier area,and community barrier area.The living ground,litter,and community environment all hindered the natural regeneration of M.glyptostroboides.The order of inhibition on its seed germination and seedling growth was community environment>living ground>litter.The dynamic changes in seedling height exhibited the S type growth curve(R~2≥0.893),whereas the seedling regeneration density in all four treatments displayed an inverted"V"shape distribution.The non-barrier treatment significantly promoted the natural regeneration of M.glyptostroboides,under which the survival rate,seedling height,base diameter,root length,leaf number,leaf area,growth rate,and biomass were the highest.Thus,for the conservation and management of M.glyptostroboides populations,the living ground cover and litter should be adequately cleared to provide a suitable environment for seed germination and seedling growth,and promote the natural regeneration of M.glyptostroboides populations in the future.

关 键 词：水杉 天然更新 凋落物 林下植被 林下活地被物 障碍因子 幼苗 群落 

分 类 号：S791.35[农业科学—林木遗传育种] S754.1[农业科学—林学]