当前松毛虫防治工作中存在问题及其意见

<正> 松毛虫是青龙县松林的第一大害虫。多年来国家和集体虽然在防止上投入了大量的人力和财力,但仍未能控制其大量发生,且为害面积逐年扩大、为害程度有逐年加重之势。在50年代全县仅零星发生,很少成灾;在60年代个别社队松林造成严重为害;到70年代全县大部发生。在隔河头、官场、草碾、牛心坨等公社都曾使万亩以上松林遭到毁灭。以后全县每年发生面积都在40万亩以上,成灾面积达20余万亩。从1971年至1980年全县防治松毛虫投资达二百多万元,因此防治松毛虫成了全县人民的一项严重负担。     

台州市竹子害虫的发生与防治初步调查

台州市有竹林3·53万hm2,20世纪90年代以来受异常气候和生态环境的影响,黄脊竹蝗Cer-acris kiangsuTsai、山竹缘蝽Notobitus montanusHsiao、竹镂舟蛾Loudonta disper(Kiriakoff)等害虫相继暴发成灾,作者2004年至2006年对该市竹子害虫的发生和防治进行了初步调查,现简报如下。1     

中国木蠹蛾研究进展情况

木蠹蛾是危害林木和果树的重要害虫。记载我国木蠹蛾的文献可以远溯到二百多年以前,近二、三十年大面积发生成灾。国内对该类害虫进行研究,始于70年代,80年代得到了较大的发展。国内对大面积发生成灾的11种木蠹蛾的生物学及防治技术进行了详细的研究,发表有关论文共63篇,仅80年代即发表39篇。中国木蠹蛾分类工作的开展,是在西北农业大学周尧教授主持与指导下进行的,我们与其合作,完成了《中国木蠹蛾志》一书的编著出版,该书包括我国木蠹蛾两亚科,13属,61种,其中有11个新种(成书前还发表过5个新种)。在防治技术方面的研究,由过去单一的化学药剂防治,发展为营林措施防治、生物防治、人工合成性诱剂使用及大面积的综合防治措施。在生物防治方面,白僵菌剂的使用,取得大面积的防治效果。人工合成性诱剂在较大范围内的试验,也获得初步成效。在大面积范围内采用综合防治措施,也取得令人满意的结果。     

秦巴山区马尾松毛虫综合防治技术研究

1986年,汉中地区南郑县马尾松毛虫危害成灾,发生总面积约866ha。其中,成灾面积280多公顷,受害株率100%,平均虫口密度124.8条,危害严重林木,针叶几乎被吃光,如同火烧,严重威胁着60年代初人工营造的近2.6万公顷马尾松林的安全。从1986年开始,汉中地区森防站、南郑县森防站等单位联合制定了马尾松毛虫生活史观察、综合防治和分年防治计划。五年来,根据不同情况进行了飞机超低容量化学药剂喷雾、烟剂、溴氰菊酯喷环、黑光灯诱杀、人工摘茧、保护天敌、营林措施等综合防治,其中飞防892ha、烟剂防治706ha,溴氰菊酯喷毒环33ha,防效十分显著,各项技术指标均达到要求,有虫株率由100%下降为11.3%,平均虫口密度由     

肃北县杨二尾舟蛾生物学特性与无公害综合治理技术

上世纪90年代开始,杨二尾舟蛾在肃北县一度严重发生,树木叶片被蚕食而光,单一的化学农药防治,造成年年防治、年年成灾恶性循环的局面.本世纪初,通过开展防治试验,改变治理策略,采取人工砸蛹、黑光灯诱杀成虫、生物农药防治幼虫等无公害综合技术措施,全面有效地控制了该虫的为害.     

在探索中走向成熟：新中国森防工作50年回顾

回首５０年森林病虫害防治工作的历史,不仅可以看出各个不同时期我国森林病虫害防治工作的方针政策和所取得的成绩,更重要的是可以总结不同时期、不同历史阶段森林病虫害防治工作取得的经验和教训,在今后的工作中加以借鉴。５０年代森林病虫害的发生和防治情况５０年代我国的森林生态环境相对较好,林中生物种群之间处于相对稳定的状态,森林病虫对林木的为害不很严重。这一时期森林病虫害的特点是发生面积小,成灾种类少。年均发生面积仅１００万公顷,为害较大的有松毛虫、竹蝗、榆金花虫、柏毛虫等,防治上主要是以人工防治为主,辅以…     

黄斑星天牛综合防治研究

黄斑星天牛在陕、甘、宁三省(区)已成灾数十年。该虫以危害杨树为主,两年发生1代,是典型的 K 类生态对策昆虫。得出的杨树抗天牛序列,抗虫的理化机制,为营造抗虫生态型林打下了基础。对白僵菌等天敌和化学防治研究结果,为协调应用有效防治技术提供了资料。为生物学、生态学、解剖学、数学模型的研究结果提供了准确预测预报的技术依据。黄斑星天牛的综合防治应以营造抗虫速生生态经济型林为基础,实行多种有效防治手段相协调,以达到有虫而不成灾的目的。     

金华市苗圃地花木主要天牛种类特性及防治初探

2012～2019年对金华市苗圃地主要成灾天牛种类、生物学特性进行了系统调查和观察研究,结果显示:主要成灾天牛种类7种,以星天牛(Anoplophora chinensis)、光肩星天牛(Anoplophora glabripennis)危害最为严重。为此,提出了应用8%绿色威雷300倍液每年防治2次,辅以其他综合防治措施可以有效控制天牛危害。     

八角尺蠖及其综合治理技术

八角是六万林场职工赖以生存的经济树种,至今为止累计种植面积达4000多公顷。八角尺蠖是八角最主要的食叶害虫,林场从上世纪60年代起一直深受其害,在多年的防治中使用了大量的化学农药,但越防治虫情越严重。林场1974年开始使用以BT粉、赤眼蜂为主的综合治理技术,取得了良好的效果,1975～1989年10年时间没用过任何化学农药也没有发生成灾现象。     

杨毒蛾防治技术关键

杨毒蛾是我区杨树重要害虫，年发生面积在20万亩以上。自1993年以来，乌苏、沙湾、和硕、和静、焉耆、博湖等地杨毒蛾又爆发成灾，来势猛，蔓延速度快，发生面积大，危害严重。近年来各地政府和森防部门组织力量，筹措防治资金全面积极开展防治。取得了一定成绩，灾情缓解。但在防治中还存在用药单一，虫情调查不及时，防治不周全，不讲防治成本等问题。1996年是能否巩固已取得成果和达到有虫不成灾预期目的关键性最后一年。为此，防治杨毒蛾应抓好几个技术关键：1、抓好越冬代幼虫防治：实践证明：杨毒蛾害虫只要掌握住有利时机，措施适当…     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.