水杉赤枯病综合营林生态控制技术研究

A study on the ecological control of red blight of Metasequoia glyptostroboides by integrated forest management

【目的】水杉赤枯病为寄主主导性病害,生态调控措施是其最佳防治策略之一。营林技术是生态调控防治病害的基础性措施。探讨营林调控技术措施对水杉赤枯病防治的效果,为赤枯病的生态防治提供指导。【方法】选择上海浦东新区绿带中的水杉纯林和混交林,采用间伐抽稀、人工透光疏枝、林间清理、施肥、松土、纯林改混交林等单因子营林措施分别开展调控试验,选择水杉纯林开展多因子营林措施随机区组综合调控试验,分析营林措施对赤枯病的防治效果。【结果】间伐抽稀、及时清理病落叶和枯死树桩以及松土,可使赤枯病病情指数有不同程度下降;轻度修剪对降低发病指数有一定作用,中度修剪对病情指数基本没有作用,重度修剪后病情指数不降反升。仅施用氮肥会使发病率、病情指数上升,而施用磷钾肥则可明显降低发病率,同时施用氮磷钾肥后病情虽有下降但不明显。进行纯林混交改造对病情的降低可起到较为明显的作用。综合营林随机区组试验得到影响感病指数减退率的主次因素依次为林相改造>林间卫生>施肥>抚育,最优综合营林措施组合为林地清扫1次+轻修剪通风+松土深翻+除草+施过磷酸钙和氯化钾+纯林改混交。【结论】合理的营林措施有助于控制水杉赤枯病的发生与危害,而综合营林措施对赤枯病具有协同生态调控作用。

Red blight of Metasequoia glyptostroboides is a typical host-dominated disease. The ecological regulation is one of the best control strategies for this disease, and forestry technology is a basic and fundamental control measure of ecological regulation.Therefore, studying the forest management and control measures could scientifically improve the control strategies for red blight of M. glyptostroboides.【Method】Pure and mixed M. glyptostroboides forests in the green belt were selected, and single factor forest management measures such as thinning, pruning, cleaning, fertilization, soil loosen and the transformation of the pure forest into the mixed forest were used to carry out experiments respectively. In addition, the pure M. glyptostroboides forest was selected to carry out the randomized block-group comprehensive control test of multi factor forest management measures. The control effects of forest management measures on red blight were calculated and analyzed.【Result】 This study showed that the disease index of red blight of M. glyptostroboides decreased to different degrees by thinning and tree density adjustment or the timely clearing of fallen leaves and dead tree stumps or loose soil. Mild pruning had a certain effect on reducing the disease index, but the disease index did not change after moderate pruning. After severe pruning, the disease index of red blight increased, and the incidence and disease index of red blight increased to different degrees after applying nitrogen fertilizer alone. The incidence and disease index were significantly reduced after the application of phosphate and potassium fertilizers. After N, P and K fertilizers were applied, the incidence and disease index decreased but were not significant. After the transformation of the M. glyptostroboides pure forest into the mixed forest, the disease index was significantly reduced. According to the results of the randomized block design of the integrated silvicultural trial, the primary and secondary relationship of the influence on the decline rate of the disease index was: forest transformation > forest health > fertilization > tending. The optimal combination level of integrated silvicultural measures was forest cleaning once + light pruning ventilation + loosening the soil and digging deep + weeding + fertilizing with calcium phosphate and potassium chloride + the transformation of the pure forest into the mixed forest. 【Conclusion】 The reasonable silvicultural measures can control the occurrence and harm of red blight in M. glyptostroboides, and the integrated forest management can be applied to collaborative ecological control effects.