马尾松毛虫危害对松树生长量影响的研究

The harmful effect of Punctata Walker to the Pinus mussoniana increasement

越冬代松毛虫的严重危害 (针叶损失 70 %以上 ) ,对当年的高生长量、胸径生长量和材积生长量有极显著影响 ;一代 (7月 )的严重危害 ,对当年和后一年的胸径生长量、材积生长量有显著影响 ,对高生长影响不显著 ;二代 (9月 )的严重危害 ,对当年的生长量无影响 ,对后一年的高生长量、胸径生长量和材积生长量有极显著影响。无论哪一代危害 ,对后

The overwintering Punctata Walker was very harmful effect to the height increasement,breast height increasement and volume increasement of Pinus mussoniana .The first generation Punctata Walker (in July)was very harmful effect to the breast height and volume increasement.The second generation Punctata Walker (in September) was not very harmful effect to the increasement in that year,but very harmful effect to the height,breast height and volume increasement next year.Both of two generations ...