促进兴安落叶松天然更新的出苗条件研究

Germination condition of assisting Larix gmelinii natural regeneration

根据４０多块标准地调查，促进更新措施后兴安落叶松１年生幼苗出现的频度及数量与种子年关系很大，幼苗更新效果最好的是种子年当年，更新频度可达６０％以上，幼苗平均为１．０—２．０×１０３株·ｈａ－１，其他年份促进的效果较差．同时，也与迹地类型、种源状况和整地质量关系较大．一般在山坡中、下部，土壤湿润的杜香落叶松和藓类越桔落叶松林迹地促进效果较好，其更新频度为６０—７０％．绝大部分更新幼苗出现在表土裸露、无杂草灌木、土壤湿润的地方．更新频度与植被盖度呈明显的衰减指数相关．促进地块距下种林墙最好不超过６０ｍ范围．

Assisting the natural regeneration of Larix gmelinii is a major measure to rehabilitate the forest vegetation of Greater Xian mountains after big forest fire. In this paper,the germination condition of assisting Larix gmelinii natural regeneration was analysed.The emergent frequency and density of Larix gemlinii seedlings after one year of assisting regeneration were largely related to seed year. The best regeneration results of seedlings came from the assistant measures in the seed year,and the emergent frequency and density of Larix gmelinii seedling reached to 70% and 1000-2000 sedlings·ha-1,respectively.The regeneration effects also related to site type,seed source,and soil preparation.In general,a good assisting result of Ledum plastre-Larix gmelinii and Moss-Vaccicum vitis-i-daea-Larix gmelinii forests can be found at middle and lower parts of slope and the regeneration frequency can be up to 60- 70%.Most regeneration seedlings of Larix gmelinii were appeared on the naked,moist topsoil.The relationship between regeneration frequency and vegetation cover clearly showed a negatively exponential curve.The effective distance of mother tree wall was less than 60m.