不同生境内厚朴种子萌发和幼苗生长研究

    Study on Seed Germination and Seedling Growth of Houpo a officinalis in Different Habitats

    • 摘要: 为揭示厚朴(Houpo a officinalis)种群实生更新方式和影响因素,在遂昌县桂洋林场内选择针叶林、针阔混交林和阔叶林3个不同生境,设置种皮和铁丝网罩交叉处理试验,研究不同生境内厚朴种子萌发和幼苗生长特征。结果显示,不同生境和不同处理间厚朴种子萌发率均有显著差异(P < 0.05),在针叶林内去除假种皮且罩铁丝网时厚朴种子萌发率最高,而保留假种皮时厚朴种子萌发率均为0。厚朴在幼苗前期(4~8周)死亡率最大,之后趋于稳定,在针叶林内幼苗存活率最高,但不同生境间差异未达到显著水平。不同生境内厚朴幼苗苗高与地径生长均表现出显著差异(P < 0.05),表现为针叶林>针阔混交林>阔叶林。林中空气温度、湿度、光照强度和枯枝落叶厚度对厚朴种子野外萌发有显著影响,其中温度、光照强度、土壤水分和养分对厚朴幼苗生长影响最大。针叶林最适合厚朴种子萌发和幼苗生长,假种皮、动物取食和生境异质性是造成厚朴种子野外萌发率低和死亡率高的主要原因。

       

      Abstract: In order to explore the mechanism of seed emergence and the factors affecting seedling regeneration of Houpoöa officinalis, three different habitats (coniferous forest, coniferous and broad-leaved mixed forest and broad-leaved forest) were selected in Guiyang Forest Farm in Suichang County. Cross-treatments of the seed coat (removing or preserving the aril) and the wire mesh (cover or not cover) were taken to reveal seed germination and seedling growth characteristics of H. officinalis in different habitats. The results show that:The seed germination rates of H. officinalis were significantly different (P < 0.05) in different habitats, and the rates of those under different treatments were significantly different too. The seed germination rate of H. officinalis under prosthetic removal and wire mesh cover in coniferous forest was the highest one; furthermore, no matter with or without wire mesh, the germination rates of H. officinalis under preserving of aril turned out to equal 0; The mortality rate of H. officinalis in the early stage of seedling (4-8 weeks) was the highest one, and it would remain stable with the age growing. In coniferous forest, the retention rate of seedling turned out to be the highest one, but there was no significant difference in retention rate between the different habitats. Differences of habitats can make significant effects (P < 0.05) on seedling height and basal stem diameter of H. officinalis. Superiority of seedling height and ground diameter of H. officinalis in coniferous forest was better than those in coniferous and broad-leaved mixed forest, and superiority of H. officinalis in coniferous and broad-leaved mixed forest was better than those in broad-leaved forest; Correlation analysis showed that factors such as air temperature, humidity, light intensity and litter thickness had a significant effect on the germination of H. officinalis seeds. For seedling growth, the important factors were air temperature, light intensity, soil moisture and nutrients. The study revealed that the coniferous forest is the most suitable for the seed germination and seedling growth of H. officinalis, and the aril, animal feeding and habitat heterogeneity are the main reasons leading to the low germination rate and the high mortality of H. officinalis seeds.

       

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