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对11~13年生西南桦纯林(初植密度包括2 m×2 m,2 m×3 m,2 m×4 m,2 m×5 m,2 m×6 m,3 m×3 m和2 m×3 m×7 m)、12年生西南桦与高阿丁枫(初植密度2 m×3m)和11年生西南桦(初植密度3 m×3 m)与山桂花(初植密度3 m×1.5 m)混交林的生长分析显示,西南桦造林后迅速进入速生期。7年生前尤为速生,速生期可延续至10年生林分,在速生期内,平均木的胸径、树高和木材年平均生长量分别为1.17~2.50 cm.yr-1、1.20~3.60 m.yr-1和0.000 11~0.018 04 m3.yr-1,其连年生长量分别为0.50~2.65 cm.yr-1、0.5~4.0 m.yr-1和0.000 11~0.018 68 m3.yr-1。西南桦纯林中,2 m×5 m和2 m×4 m的初植密度较为有利于林木生长和木材生产,其13年生林分生长量分别达:(1)年平均胸径1.42 cm.yr-1和1.72 cm.yr-1,年平均树高1.77 m.yr-1和1.72 m.yr-1;(2)单位面积材积为209.807 1 m3.hm-2和208.933 8 m3.hm-2,并且胸径>16 cm的林木分别占80.00%和60.00%。混交林的木材产量:(1)12年生西南桦与高阿丁枫混交林单位面积木材产量是同林龄西南桦纯林(初植密度2 m×3 m×7 m)的1.845倍(172.363 7 m3.hm-2比94.978 9 m3.hm-2);(2)11年生西南桦与山桂花混交林单位面积木材产量是同林龄西南桦纯林的2.774倍(158.742 0m3.hm-2比57.219 0 m3.hm-2)。在西南桦与高阿丁枫混交林中,1行西南桦与2行高阿丁枫混交模式能提高西南桦高生长和木材产量。高阿丁枫和山桂花是可以同西南桦相匹配营造混交林的两个云南热带乡土树种。
For 11 ~ 13 year-old Betula platyphylla plantations, the initial planting density including 2 m × 2 m, 2 m × 3 m, 2 m × 4 m, 2 m × 5 m, 2 m × 6 m, 3 m × 3 m and 2 m × 3 m × 7 m), 12-year-old Betula alnoides and tall alpine maple (initial planting density 2 m × 3 m) and 11-year-old Betula alnoides (initial planting density 3 m × 3 m) 3 m × 1.5 m) The growth analysis of mixed forest showed that the southwest birch quickly entered the fast-growing stage after afforestation. The 7-year-old was particularly fast-growing, and the fast-growing period could be extended to 10-year-old stands. The average DBH, tree height and annual average wood annual growth rate were 1.17-2.50 cm.yr-1.20-3.60 m during fast-growing period. yr-1 and 0.000 11-0.018 04 m3.yr-1, respectively. The annual growth rates were 0.50-2.65 cm · yr -1, 0.5-4.0 m · yr -1 and 0.000 11-0.018 68 m · yr -1, respectively. In the pure Betula albosinensis, the initial planting density of 2 m × 5 m and 2 m × 4 m was more favorable for tree growth and wood production, and the growth of 13-year-old stands were (1) 1.42 cm.yr -1 and 1.72 cm.yr-1 respectively, the average annual tree height is 1.77 m.yr-1 and 1.72 m.yr-1; (2) The unit volume is 209.807 1 m3.hm-2 and 208.933 8 m3.hm-2 , And trees with DBH> 16 cm accounted for 80.00% and 60.00% respectively. Wood production in mixed forest: (1) The timber yield per unit area for 12-year-old mixed Betula alnoides and A. tabulaeformis forest is 1.845 times that of pure Betula platyphylla forest (initial plantation density 2 m × 3 m × 7 m) (172.363 7 m3.hm-2 than 94.978 9 m3.hm-2). (2) The wood yield per unit area of 11-year-old mixed Betula alnoides and Osmanthus fragrans was 2.774 times (158.742 0m3.hm-2) Than 57.219 0 m3.hm-2). In the mixed forest of Betula alnoides and High-Alting-Dingfeng, the mixed mode of Betula platyphylla and Betula altaica can improve the height growth and wood yield of Betula alnoides in southwest China. High Alpine maple and mountain sweet-scented osmanthus trees can be matched with Southwest birch to create a mixed forest of two tropical Yunnan native species.