大兴安岭林区气候嚴寒,桦木种子在八月下旬至九月上旬成熟。其它地区气候比較温暖,可以提前15——20天成熟。 樺木果实成熟时期的特征是:果穗呈黃褐色,用手指一捻立即散开。采种应在种子完全成熟的前几天進行,但不要从幼齡的母樹上采集,因为幼龄母樹所結的种子發芽率很低(只有8——15％);此外,要避免采集帶有僵化病的种子。这样才能保証种子的質量,使采集的种子有較高发芽率(一般可以达到30——40 Daxinganling forest climate is cold, birch seeds mature in late August to early September. The climate in other areas is relatively warm and can mature 15-20 days in advance. Birch fruit ripening period is characterized by: yellowish brown ears, a twist with your fingers immediately spread. Seeds should be harvested a few days prior to the full maturity of the seed, but not from the young mother tree because young seedlings have low germination rates (only 8-15%); in addition, Fossilized seeds. In order to ensure the quality of the seeds so that the seeds collected have a higher germination rate (generally can reach 30 - 40