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赤峰市黄褐天幕毛虫发生与防治措施 总被引：1，自引：1，他引：0
《内蒙古林业调查设计》2016,(4)
2002年以来,黄褐天幕毛虫Malacosoma neustria testacean在赤峰市中部、北部的山杏Armeniaca sibirica林内每4 a大发生一次。采取人工、生物、化学、飞机防治等综合防治措施,有效防控黄褐天幕毛虫大发生,保持森林生态平衡。 相似文献
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阳高县杏树黄褐天幕毛虫防治技术 总被引：1，自引：0，他引：1
黄褐天幕毛虫属于鳞翅目枯叶蛾科害虫，对于杏树危害极大。介绍了黄褐天幕毛虫生物学特性、形态特征以及在阳高县发生现状、发生规律和防治办法。 相似文献
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桦树天幕毛虫正在蔓延成灾 总被引：1，自引：0，他引：1
<正> 桦树天幕毛虫Malacosoma rectifascia Lajonquiere又名绵山天幕毛虫。“中国森林昆虫”一书记载国内分布于山西。1982年河北省森林病虫普查资料汇编记载,在我省保定地区中度发生,事隔3年,1985年6月我们在蔚县小五台林场南台和赤城县大海陀林场调查,发现桦树天幕毛虫为害白桦相当普遍。该虫将白桦叶子吃光,虫体成堆将树枝压弯,一树吃光之后再迁移它树。据当地群众反映,该虫最近几年由无到有,由少 相似文献
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天幕毛虫Malacosoma neustria testaceaMotschulsky.周期性大发生,往往造成杨、柳、柞、桦、落叶松等林木的严重危害。建国以来,天幕毛虫在牡丹江市林区三次猖獗为害,究其原因,除食物丰富生境适宜外,气象 相似文献
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苦参碱是一种植物提取制剂，相比目前采用的砒虫啉杀虫剂和有机磷杀虫剂而言具有无公害、保护环境、不产生污染和保护食虫天敌安全等特点。文章做了不同浓度3％苦参碱防治天幕毛虫（Mulacosomaneustria testacea Morsch）的试验，结果表明，用3％水溶性苦参碱800～1000倍液，能有效地防治天幕毛虫，天幕毛虫总死亡率达到100％。 相似文献
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天幕毛虫(Malacosoma neustria tes-tacea Motschulsky)是森林、果园的食叶害虫,大发生时常把树叶吃光,乃至造成全林死亡。为了探讨寄生蜂对该虫的抑制作用,笔者于1978～1984年,对其8种寄生蜂的发生、消长,寄生与利用等情况,进行了观察和试验。1 寄生蜂种类观察发现,天幕毛虫卵、幼虫、蛹期寄生蜂有以下8种。(见表1)2 生物学特性2.1 越冬态上述8种寄生蜂的越冬态有以下5种。以幼虫和蛹在寄主卵内越冬(如松毛虫赤眼蜂和大蛾卵跳小蜂);以幼虫和蛹在寄主幼 相似文献
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天幕毛虫卵、幼虫、蛹期的寄生蜂计有8种,其寄生方式有5种。据300亩柞、椴、榛混交林调查其天幕毛虫幼虫、蛹的寄生率为41%、28.4%。并对其生物学特性(越冬态、发生期、发生量、寄生方式、寄生率、寿命)进行了观察。 相似文献
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马尾松毛虫暴发机制分析 总被引：11，自引：0，他引：11
马尾松毛虫的暴发过程具有周期性和突发性相结合的特点,不同环境条件下,即不同的发生区,发生类型不一样,常灾区是典型的暴发发生类型,偶灾区和无灾区一般为渐进发生型、扩散发生型和低密度稳定发生型.暴发的原因一方面是马尾松毛虫具备了成为暴发种的遗传特性,另一方面是大面积马尾松纯林的存在.暴发的启动因子为高温干旱或由环境噪音引起的混沌动态,暴发的上升期为正密度相关作用驱使,下降期和潜伏期主要是由松树诱导抗性、严重失叶和天敌所引起的负密度相关的作用.松林和松林节肢动物群落结构的多样性是抑制马尾松毛虫暴发的主要因素. 相似文献
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《Forest Ecology and Management》2004,201(1):89-104
Samples of Norway spruce (Picea abies [L.] Karst) were dendrochronologically investigated in order to detect infestations by Dendroctonus micans (Kug.), the great spruce bark beetle (Col. Scolytidae), a relatively recent introduction to France. Uninfested natural forests located in the north-eastern French Alps and heavily infested plantations in the Ardèche region (Massif Central) were compared. The penetration holes bored in trunks by the bark beetle induced visible marks on wood, such as extreme ring width reductions, locally missing rings and crescent-shaped resin patches between consecutive rings that make possible a post-infestation dating.The outbreak began in 1979, 5 years prior to first insect visual detection by foresters. In the infested forest, tree basal area growth was not as sustained as in uninfested natural stands, but showed an inflection point at an unusually young tree age (from 30 to 40 years). Ring widths showing extreme synchronous radial growth reductions were caused either by excessively cold periods (e.g. in 1948, 1980, 1984, 1992) or by summer drought (as in 1986). Most of these weak growth years were shared with uninfested sites. In healthy forests, the consequences of extremely cold years were usually recorded only in high elevation stands, especially near the timberline, whereas summer drought effects were mostly visible in low altitude forests. By contrast, both phenomena were recorded in the infected Ardèche plantation. An analysis of tree-rings and monthly climate confirmed that Norway spruce growth in Ardèche plantations was reduced by excessively low minimum temperature during most parts of the year prior to ring formation, by higher than average maximum temperature during current spring and summer, and by drought in winter, spring and summer. Thus, the regional Ardèche climate with both cold winters and dry summers (especially in July) seems to weaken spruce trees planted there. Moreover, tree sensitivity to climate was found to be greatly enhanced by insect infestation. Such interactions between climatic stress and insect outbreak led to forest dieback in a 15–20-year period, when trees were still young (less than 70 years), and without any tree recovery. Therefore, in that region spruce plantations should be replaced by non-host species of Dendroctonus micans, especially where soil conditions may exacerbate drought effects. 相似文献
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Outbreaks of bark beetles and drought both lead to concerns about increased fire risk, but the relative importance of these two factors is the subject of much debate. We examined how mountain pine beetle (MPB) outbreaks and drought have contributed to the fire regime of lodgepole pine forests in northwestern Colorado and adjacent areas of southern Wyoming over the past century. We used dendroecological methods to reconstruct the pre-fire history of MPB outbreaks in twenty lodgepole pine stands that had burned between 1939 and 2006 and in 20 nearby lodgepole pine stands that were otherwise similar but that had not burned. Our data represent c. 80% of all large fires that had occurred in lodgepole pine forests in this study area over the past century. We also compared Palmer Drought Severity Index (PDSI) and actual evapotranspiration (AET) values between fire years and non-fire years. Burned stands were no more likely to have been affected by outbreak prior to fires than were nearby unburned stands. However, PDSI and AET values were both lower during fire years than during non-fire years. This work indicates that climate has been more important than outbreaks to the fire regime of lodgepole pine forests in this region over the past century. Indeed, we found no detectable increase in the occurrence of high-severity fires following MPB outbreaks. Dry conditions, rather than changes in fuels associated with outbreaks, appear to be most limiting to the occurrence of severe fires in these forests. 相似文献
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Felix Gugerli Rolf Gall Franz Meier Beat Wermelinger 《Forest Ecology and Management》2008,256(3):405-409
The dynamics of a recent outbreak of the spruce bark beetle (Ips typographus) in Switzerland was ruled by a devastating winter storm in 1999 and the drought and heat of the summer 2003. Starting from a similar level of population sizes, estimated as the rate of infested growing stock, beetle populations increased differently in magnitude and time among different regions in Switzerland. Accordingly, we expected local or regional genetic differentiation as a result of such repeated population expansion/breakdown dynamics. We analyzed 5 nuclear microsatellites of spruce bark beetles sampled from pheromone traps at 30 locations distributed over Switzerland. Our genetic results did not indicate any sign of population differentiation, structure, isolation by distance, or recent bottlenecks. This complete lack of genetic structure suggests that spruce bark beetles are highly mobile, precluding the formation of a spatial structure at neutral molecular markers. Thus, this molecular–genetic approach does not allow us to discriminate among regional gene pools and to identify the origin of expanding beetle populations. 相似文献
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Following the severe drought in 1999–2000 there was a widespread outbreak of oak decline in the Ozark Highlands. Over 400,000 ha of dead and dying oak trees were observed by the USDA Forest Service in this region. Although oak forests that are dead can be easily interpreted from air photos or classified from satellite images, it is difficult to detect dying trees that are still green but will die back or recover in the following years. In this study, we applied a normalized difference water index (NDWI) to map the continuous forest dynamics related to oak decline. The Landsat TM image in 1992 and the ETM+ image in 2000 were processed to calculate the differential NDWI which revealed moisture variation primarily caused by the drought and the associated red oak borers. A simple thresholding method was used to map oak dying back, recovery and non-change areas in the study area. The died-back areas were extracted from the modified land use/land cover maps created by the Missouri Resource Assessment Partnership (MoRAP). The forest dynamics map was compared with the online FIA database in which tree species at randomly selected sites were recorded in 1989 and 2003. The overall accuracy of forest dynamics mapping with remote sensing imagery was 75.95%. The user's accuracy of dying/recovery area mapping was also high although the producer's accuracy is questionable because of the limitation in ground data collection. The continuous dying/recovery map in this study could provide valuable information on the prediction of oak decline and evaluation of damage when another period of environmental stresses occurs. 相似文献
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国外苗圃栽培措施对树种抗旱性影响的研究综述 总被引：3，自引：1，他引：2
干旱是阻碍全球林业发展的一个重要因素, 故各国对树木抗旱性的研究非常重视。在育苗阶段, 通过不同栽培处理, 如水分胁迫、施肥、生长抑制剂、菌根菌、光周期等, 研究苗木对干旱的形态适应性和生理适应性, 为培育抗旱树种提供了理论依据, 对增强苗木抗旱性, 提高造林成活率有重要意义。 相似文献
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骆宗诗 王亿成 慕长龙 范成绪 向成华 童伟 李建贤 孟宏伟 包建华 杨朝俊 胥怀清 鄢武先 孙鹏 闵安明 张建明 宋永全 张茂祥 赵顺才 郭小军 周厚兰 《四川林业科技》2007,28(3):44-49
2006年四川发生了百年一遇的特大干旱。通过对四川盆地丘陵区重灾区的16个县104个乡镇4489.3公顷林地的调查结果表明,受干旱影响较大的是新造林地的林木和幼林,中龄林和成熟林则表现出很大的耐早能力,对林地进行经营和管理,可提高林木抗御干旱能力。调研还表明受旱较量的树种主要有:桤木、巨桉、杉木和葡萄等,受旱稍重的树种主要有:杨树、绵竹、麻竹、慈竹、茶树和花椒等,受旱较轻的树种主要有:马尾松、柏木、大枣、油桐和枇杷等。 相似文献
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本文对来自不同地区的24种白三叶种质材料进行对比研究,调查不同种质材料在长沙2013年夏季旱灾后的恢复情况和2014年“倒春寒”后各种质材料的存活及返青情况。结果表明,植株高度和匍匐茎长短与白三叶耐旱情况成正比,而干旱后返青速度越快的白三叶材料,遇到寒冷时死亡速度越慢。同时从中选出了三类适合于华中地区种植的材料类型,第一类为既耐旱又耐寒的02485和海发,第二类为较耐旱不耐寒,但返青速度快的02478、00858、CF022549和00605,第三类为不耐旱但耐寒、返青速度快的百事吉、和谐、贵州大方和02587。 相似文献