Clarification of Factors Inhibiting Regeneration of Glehn's spruce (Picea glehnii) at the Initial Stage of Natural Regeneration

研究了生长初期真菌、田鼠、林底水分和光环境等因素对格伦云杉自然再生的影响。对自然苗木生长环境进行了分析。从森林地面下过冬的格伦云杉种子中分离出6种丝状真菌。其中，使种子腐烂的瑟氏Racodium therryanum、使幼苗倾倒的soloctonia solani和镰刀菌Fusarium rosume是显著的真菌类型。在长满莎草的森林里，田鼠经常吃种子，而在裸露的土地上，由于地面刮擦，被吃掉的种子数量减少。通过表面刮除莎莎，限制了田鼠的活性，提高了种子的存活率。在土壤含水量的季节变化中，L层变化明显，从10%到70%不等。结果表明，L层以上的种子容易脱水死亡。在光环境方面，研究发现30%以上的相对照度对育苗和种植云杉的充分生长是必要的。格伦云杉的自然幼苗生长在长满苔藓的森林地面、倒下的树木、土丘、树桩和光秃秃的土地上。人们认为，在森林中小面积的表面刮削对加速自然更新是有效的。

Research was conducted on factors preventing natural regeneration of the Glehn's spruce (Picea glehnii) at early stages of growth, such as fungi, field mouse, moisture in forest floor and photoenvironment. Analysis of the environment where natural seedlings grow was also conducted.Six species of filamentous fungi were separated from Glehn's spruce seeds which had passed the winter under the forest floor. Among those, Racodium therryanum, which rotted the seeds, and Rhizoctonia solani and Fusarium rosume, which dumping-off the seedlings, are the significant types of fungi. While seeds are often eaten by fiels mouse in forest thicks with Sasa, the number of seeds eaten decreased on bare land where the ground had become exposed due to surface scraping. By removing Sasa by surface scraping, the activity of field mouse was limited and the survival rate of seeds was jmproved. Regarding the seasonal changes of water content in the soil, it changed sharply in the L layer, from 10 to 70%. It was found that seeds above the L layer were prone to dehydrate and die. As for photoenvironment, it was found that more than 30% relative illumination was necessary for sufficient growth of seedlings and planted Glehn's spruce trees. Natural seedlings of the Glehn's spruce grow on mossy forest floors, fallen trees, mounds, stumps and bare land. Surface scraping of small areas in the forest is thought to be effective for hastening natural regeneration.