轻型飞机喷洒Bt油悬浮剂防治马尾松毛虫试验

运用轻型飞机喷洒Bt油悬浮剂防治马尾松毛虫Dendrolimus punctatus Walker，施药后第3天马尾松毛虫死亡率为73．79％，第25天死亡率达95．81％。     

灭幼脲Ⅲ号在林间松针上的残留动态及持效作用研究

本文研究的是在林间自然条件下，施用灭幼脲Ⅲ号（Ｄｉｍｉｌｉｎ－３）胶悬剂防治马尾松毛虫，药剂在林间松针上的残留动态及残效期。试验结果表明，林间用３００ｐｐｍ浓度的灭幼脲Ⅲ号胶悬剂在松针上的消解方程为Ｃ＝４６．４４３２５Ｅ＾－０．０１４５ｔ，半衰期为４７．８天，药剂在松针上的即时附着量为５３μｇ／ｋｇ。它对第１代马尾松毛虫１龄幼虫的持效期为４０￣５０天，第２代３０￣４０天，第３代长达５６天以上。     

灭幼脲Ⅲ号在林间松针上的残留动态及持效作用研究

本文研究的是在林间自然条件下，施用灭幼脲Ⅲ号（Ｄｉｍｉｌｉｎ－３）胶悬剂防治马尾松毛虫（Ｄｅｎｄｒｏｌｉｍｕｓｐｕｎｃｔａｔｕｓ），药剂在林间松针上的残留动态及残效期。试验结果表明，林间用３００ｐｐｍ浓度的灭幼脲Ⅲ号胶悬剂在松针上的消解方程为Ｃ＝４６．４４３２５Ｅ－０．０１４５ｔ，半衰期为４７．８天，药剂在松针上的即时附着量为５３μｇ／ｋｇ。它对第１代马尾松毛虫１龄幼虫的持效期为４０～５０天，第２代３０～４０天，第３代长达５６天以上。     

4种无公害药剂林间防治马尾松毛虫试验

2009年,在福建省将乐县对虫龄3~4龄越冬代马尾松毛虫,选用白僵菌、苏云金杆菌、森得保、25%阿维灭幼脲等4种无公害药剂进行林间防治马尾松毛虫试验。结果表明,4种药剂对马尾松毛虫防治效果达86%以上,其中森得保和阿维灭幼脲药效快,对高虫口林分控制效果好;白僵菌药效慢,但持效性好。并根据2010—2014年各年度不同发生区林间虫口密度,有针对性地选择药剂进行大面积防治试验,5 a间应用4种药剂防治马尾松毛虫总平均防治效果达90.54%,且没有对环境造成不良影响。6 a的试验结果表明,4种药剂采取机动喷粉或超轻型飞机大面积防治,工效高,而且高效、稳定、安全、持效,是值得推广的生物杀虫剂。     

马尾松毛虫生物防治技术要点

马尾松毛虫是一种严重危害马尾松、湿地松等松树的害虫。本文介绍了对马尾松毛虫有很好防治效果的白僵菌、苏云金杆菌、多角体病毒等几种生物防治药剂，并详细介绍了运用这些药剂防治马尾松毛虫的技术、方法以及注意事项等，还对生物防治中所存在的一些问题进行了探讨。     

新干县用白僵菌防治马尾松毛虫成效显著

“白僵菌防治马尾松毛虫技术应用与推广”项目在新干县通过了吉安地区科委组织的技术鉴定,填补了南方地区大面积推广应用白僵菌防治马尾松毛虫技术的空白。 马尾松毛虫是国内危害森林最为严重的森林病虫害之一。新干县是一个丘陵县,松林面积占全县林业用地面积的32.1％,且大部分集中分布在人为活动较频繁的105国道、京九铁路沿线及赣江沿岸的乡村。马尾松毛虫危害曾十分严重,每隔3年—4年为一猖獗周期,被江西省列为马尾松毛虫“常灾区县市”。以往单纯使用化学药剂     

森得保粉剂防治马尾松毛虫效果初报

马尾松毛虫Dendrolimus punctatus(Walker)是南方松林常见害虫,呈周期性暴发,一旦暴发,发生面积往往很大,给防治工作带来一定的难度,作者在2004年6月开展了喷施森得保粉剂防治马尾松毛虫试验。1试验地概况防治试验区设在江西省上犹县梅水乡水径村,该地区为丘陵山地,海拔157~235 m,高差在30~80 m之间。防治试验区面积为247 hm2,林分为马尾松纯林,胸径4~16 cm,树高4~12 m,郁闭度0·7~0·8。供试虫为马尾松毛虫第1代幼虫,多为3~4龄,虫口密度在35~480条/株,有虫株率为99·5%。2材料与方法防治药剂为乐斯化学有限公司生产的森得保可湿性粉剂,喷…     

白僵菌防治松毛虫的应用

我国自上世纪50年代开始研究和应用白僵菌以来，在防治农林害虫上发挥了巨大作用，特别是在马尾松毛虫防治上，不仅对马尾松毛虫致病性强，不杀伤天敌，能促使防治工作步入良性循环，而且可制成粉剂、粉炮等施放，林农使用十分方便，是林业防治马尾松毛虫应用面积最大、最为成功的事例之一。     

飞机防治马尾松毛虫关键技术探讨

阐述了湖南邵阳市新宁县飞机防治马尾松毛虫工作中方案制定、作业区的选择、确定最佳防治时期、机型选择、起降场选择、防治药剂选择、防治作业准备工作等10项关键技术,以期对马尾松毛虫有较好的防治效果。     

Bt乳剂防治马尾松毛虫试验初报

Bt乳剂是一种广谱微生物杀虫剂,属苏云金杆菌系列。用BT乳剂200ml/亩,防治越冬2～3龄马尾松毛虫,15天平均药效为78.39%。防治第一代3～4龄马尾松毛虫,7天平均药效为71.04%。BT乳剂有抑制下代马尾松毛虫繁殖量的作用,对寄生无效影响较少,经济成本低于白僵菌、赤眼蜂等生物制剂。     

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.