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“自然控制”是通过人为措施,促进林木郁闭,形成合理的林分结构,建立相对平衡的生态体系;从而利用森林生态环境条件、调节生物种群、调整生态类型、保护天敌,控制松毛虫灾情的一种调控系统。马尾松林在人工促进下,可形成这种调控系统,在这个调控系统里,松毛虫个体发育速度慢,种群数量增长幅度小、发生世代少。虫口密度可下降到0.17—2.04头/株,下降率平均达80.20—96.85％,且日趋稳定,可实现林间局部“自控”,达到较好的防治效益。结合“分类施策”“综合控制”,试验林“自控”面积的比例可逐年提高,3年可达总面积的49.26％,化学防活面积比例可降到3.31％,天敌保存率可达96.69％,松毛虫虫口密度可下降到3.2头/株,下降率平均达85.12％,做到“有虫不成灾”,可控制松虫灾情。同时林内林木长强壮,与一般林地比较,马尾松高生长年平均增加0.3—0.8m,胸径年平均增加0.4—0.5cm;植被繁茂,极有利于恢复林间自然生态平衡。“自然控制”是控松毛虫灾情一条新的有效途径。
The “natural control” is through artificial measures to promote forest canopy closure to form a reasonable stand structure and establish a relatively balanced ecological system; thus using the forest ecological and environmental conditions, regulating biological populations, adjusting ecological types, protecting natural enemies and controlling the pine caterpillar disaster A regulation and control system. Masson pine forest under artificial promotion, can form this regulation system, in this regulation system, the individual development of pine caterpillars slow, population growth rate is small, less generation. Insect population density can be reduced to 0.17-2.04 head / strain, the average decline rate of 80.20-96.85%, and has become increasingly stable, can achieve local “self-control” to achieve better prevention and treatment benefits. In combination with “classified control” and “integrated control”, the proportion of “controlled” area of experimental forests can be increased year by year, reaching 49.26% of the total area in three years, reducing the proportion of chemical resistant areas to 3.31% and preserving natural enemies by 96.69% , Dendrolimus population density can be reduced to 3.2 head / strain, the average rate of decline reached 85.12%, so that “no worms,” can control the pine worm disaster. At the same time, the woods in the forest were long and strong. Compared with the general woodland, the growth of Pinus massoniana increased 0.3-0.8m on average and the average DBH increased 0.4-0.5cm. The vegetation was lush, which was very beneficial to restore the natural ecological balance in the forest. “Natural Control” is a new and effective way to control the disaster of pine caterpillars.