河北坝上疏缓丘陵华北落叶松人工林生长特性研究

STUDY ON THE GROWTH CHARACTER OF ARTIFICIAL LARIX PRINCIPIS-RUPPRECHTI FOREST ON GENTLE HILLS IN BASHANG REGION

研究表明，坝上疏缓丘陵区华北落叶松（Ｌａｒｉｘｐｒｉｎｃｉｐｉｓ－ｒｕｐｐｒｅｃｈｔｉｉ）人工林高１５龄前生长阴坡大于阳坡，１５－２１龄高生长从大到小依次为阴坡中部、阳坡下部、阴坡下部；直径、材积生长阳坡大于阴坡。因此，在降水量、气温均低于华北落叶松天然分布区的坝上地区，丘陵阴坡水分条件较好，强阳性树种华北落叶松幼树生长较快，容易形成人工片林，而丘陵阳坡热量条件较好，幼树生长较慢，但成林后林分生产力较高。丘陵阴坡中部的华北落叶松人工林，２８龄后可进行天然更新，而其它立地３０龄以前不能天然更新。

Investigation showed that the height growth of artificial larix principis-rupprechti forest on gentle hills in Bashang region was higher on shady slope than on sunny slope as the forest was under 15years old : for the15-20-year-old forest their height growth was in the order:mid-shady slope>lower sunny slope>lower shady slope but their diameter and timber- growing amount were higher onsunny slope than on shady slope. The young trees of larix principis-rupprechti grow faster on shadyslopes than on sunny slopes due favourable water condition;However,the established forest on sunnyslopes of hills have a higher preductivity due to favourable heat condition. The artificial forest onmiddle shady slopos could be naturally regenerated at 28 years old but for other sites they shouldn’t be regenerated before 30 years old.。