祥云新松叶蜂种群密度简易估计方法及防治研究

通过祥云新松叶蜂（Ｎｅｏｄｉｐｒｉｏｎｘｉａｎｇｙｕｎｉｃｕｓ）低龄幼虫和茧空间分布格局及参数ｍ＊、Ｋ、α、β值估计低龄幼虫林间种群密度ｍ＝７５６３－７６０６Ｐ０、茧林间种群密度ｍ１＝０．９４６３（Ｐ－１．０５６７０－１）×１００;在９月初至１０月中旬,以２．５％敌杀死乳油、２５％灭扫利乳油２００００倍进行超低量喷雾,选择性防治有虫株,防治效果达９２．４０％。在１１月上旬至１１月中旬对小面积虫源地、林缘地带林及个别高大树株,用１５％杀虫双水剂每株５ｍｌ进行注干防治,防治效果为９０．００％。在１１月至１２月上旬,采用敌马烟剂放烟,防效达９７．８１％。在６月下旬至７月上旬,在高虫口成灾区,人工刨茧,防效达８６．１０％。     

枣尺蠖为害榆树的生活习性及防治研究

本文首次详述了枣尺蠖为害输树的生活习性及特性。采用塑料膜围干防效达９０％；４０％氧化乐果原液涂干防效达９２％；３Ｔ呋喃丹和铁灭克灌根（株施量分别为５０．１５ｇ）防盗为９８．８％和９７．２％；１５０×１０＾－６的灭幼脲１号林间喷雾防效达９８．２％。     

小窄径茧蜂林间套笼接蜂试验

小窄径茧蜂林间套笼接蜂试验结果表明,影响小窄径茧蜂寿命和林间寄生活动的主要因素是接蜂时间和套笼内温度。７ 月下旬接蜂,寄生率为８．５２％ ～８．９０％ ,７ 月上旬接蜂,寄生率只有１．４０％ ～２．１６％ 。笼内温度超过３０～３４℃,小窄径茧蜂存活时间只有２～４天,少数可存活６～７ 天。在抚顺地区７ 月下旬至８月初是小窄径茧蜂寄生活动的最佳时间。试验表明,小窄径茧蜂可以在我国兴安落叶松鞘蛾上寄生并安全越冬。     

微红梢斑螟对国外松的危害及防治研究

微红梢斑螟对国外松的危害比较普遍,据在湖南52块标准地调查,占被调查块数的71.15％;被害株率为10.13％。其中最严重1块为3年生火炬松幼林,被害株率达87.5％;单株受害梢严重的达28个枝条之多、主要是主梢和上部1—2轮生侧梢。此虫在湖南一年发生二代,生活史极不整齐,以幼虫在被害处越冬。化学和生物林间防治试验证明,多种化学药剂防治均有一定效果,而生物防治则以白僵菌防效明显。化防林间喷雾以2.5％溴氰菊酯2000倍液最好,防效可达53.97—64.81％;生防林间措施以含孢量65/克白僵菌,每亩1公斤,死虫率达73.91％。     

龙眼扦插育苗及丰产栽培技术研究

采用文中所介绍的技术、龙眼扦插４０天后即产生愈伤组织，愈合率达８６．６％；６０－９０天大量生根，生根率达８７．２％成活率达７４．５％；９０天后即可进行苗地移栽，成活率达９０．５％，１年一苗高６０－１５０ｃｍ，地径０．６－１．５ｃｍ，此时即可邮圃定植，２－３年挂果，４年进入丰产期，丰产效果显著。     

竹卵圆蝽生物学特性观察及其无公害防治试验

于2002—2008年在常德市鼎城区林业科学研究所进行竹卵圆蝽生物学特性观察和防治试验,结果表明：该虫在湖南省1年发生1代;林间释放平腹小蜂（Anastatus japonicus Ashmead）防治竹卵圆蝽效果良好,寄生率达69．61％-81．83％,平均为75.68％,因此利用平腹小蜂是一种行之有效的无公害的生物防治措施;在林间补充中间寄主柞蚕卵防治效果较好,补充区竹卵圆蝽卵平均寄生率高达52．68％,而对照区平均寄生率仅23．79％,补充区竹卵圆蝽卵寄生率明显比对照区寄生率提高28．89％。     

云杉根小蠢综合防治技术研究

经测定，斯氏线虫属的５种病原线虫对云杉根小蠢Ｈｙｌａｓｔｅｓｃｕｎｉｃｕｌａｒｉｕｓ的侵染力，以芫普夜蛾线虫ＳｔｅｉｎｅｒｎｅｍａｆｅｌｔｉａｅＡｇｒｉｔｏｔｏｓ致死能力最强。该线虫对后期的蛹和高龄幼虫的致死能力明显高于前期的蛹，１：８０用量４８小时的致死率分别为９７．５％、９２。０％和３．３％。林间将线虫喷洒在云杉伐桩四周，每ｍ￣２用量２×１０￣５－２４×１０￣５头之间，施后１２天寄生率达５３．４％－９５．６％。云杉采伐后及时处理伐桩和保留地理设饵木，均可减少害虫的发生。云杉更新时采用根径大于ｌｃｍ以上的大苗，并于植前用柴机油混合涂剂或辛硫磷药糊涂刷树苗极颈部，保护树苗，防治效果均好．     

应用质型多角体病毒防治赤松毛虫林间试验

赤松毛虫严重危害油松、赤松、落叶松的正常生长,为了选择安全有效的防治方法,在林间开展赤松毛虫的防效试验。通过抽样调查卵期赤眼蜂寄生率、2龄幼虫病毒感染率、幼虫下树前死亡率和越冬后幼虫死亡率,对直接喷洒传递松毛虫质型多角体病毒(CPV)和利用赤眼蜂为媒介传递该病毒的防效进行比较。结果显示:赤松毛虫卵期赤眼蜂寄生率比对照提高25%左右。直接喷洒CPV病毒的防效要优于利用赤眼蜂携带CPV病毒进行防治的效果,2龄幼虫病毒感染率、幼虫下树前死亡率和越冬后幼虫死亡率分别提高20%、4.1%和4.0%,二者的防治效果,明显高于对照。     

华栗绛蚧的天敌研究

记述华栗绛蚧天敌18种,其中捕食性天敌7种,捕食率在25％以上;寄生性天敌11种,最高寄生率达62．7％。林间有天敌优势种7种     

德昌松毛虫质型多角体病毒防治大柏毛虫应用研究

应用德昌松毛虫质型多角体病毒ＤｅｎｄｒｏｌｉｍｕｓｐｕｎｃｔａｔｕｓｔｅｃｈａｎｇｅｎｓｉｓＣｙｔｏ－ｐｌａｓｍｉｃＰｏｌｙｈｅｄｒｏｓｉｓＶｉｒｕｓ（ＤｐｔＣＰＶ）防治四川内地柏木林区大柏毛虫Ｄ．ｈｏｕｉＬａｊｏｎ－ｑｕｉｅｒｅ的试验表明，以７．５×１０９ＰＩＢ／６６６．６ｍ２以上剂量防治３龄幼虫，其综合防效达８５％以上，且具有显著的扩散流行和持续防治效果。     

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.