川硬皮肿腿蜂防治云斑天牛试验初报

采用川硬皮肿腿蜂(Scleroderma sichuanensis Xiao)对云斑天牛(Batocera horsfieldi Hope)幼虫进行室内及林间寄生试验，结果表明，川硬皮肿腿蜂可以对云斑天牛一龄幼虫寄生。其室内攻击天牛幼虫致死率为100％。林间防治有效率为61．11％，室内寄生生产卵率为62．5％，子代蜂的出蜂率为20．83％，对云斑天牛具有一定的持续防治效果。而对个体较大的接近老熟的幼虫则无法寄生。寄生成功后，川硬皮肿腿蜂母代蜂寿命会延长至子代蜂幼虫化蛹。     

川硬皮肿腿蜂对光肩星天牛幼虫的寄生试验

通过开展川硬皮肿腿蜂对光肩星天牛幼虫的寄生试验,发现将川硬皮肿腿蜂接入天牛幼虫试管中后,肿腿蜂约20min以内对天牛幼虫的攻击率达100%。约2～7d后产卵,寄生率94.87%,卵期2～4d,幼虫期4～6d,结茧率89.19%,蛹期11～15d,羽化率75.76%,最终完成生活史。结果表明:川硬皮肿腿蜂从取食到产生后代,完成完整生活史,根据气温情况,大概需要30～40d左右。且试验显示川硬皮肿腿蜂对光肩星天牛的低龄幼虫有较强的寄生致死效果。     

川硬皮肿腿蜂与中华甲虫蒲螨协同防治天牛类蛀干害虫技术研究

根据川硬皮肿腿蜂(Scleroderma scichuanensis Xiao)和中华甲虫蒲螨(Pyemotes zhonghuajia)的作用特点和优势,主要以协同防治天牛类蛀干害虫为例,进行野外释放及防效研究。结果表明:川硬皮肿腿蜂和中华甲虫蒲螨对天牛均有控制作用,两者的交互作用,平均寄生率为52.8%,虫口减退率为54.62%,防治效果均优于农药;二者作用时期不同,蒲螨对低龄幼虫寄生率高,肿腿蜂对中高龄幼虫寄生率高。在防治时,应根据两者的作用特点和优势,在不同时间(龄期)进行2种天敌的先后释放可达到较高的寄生率和虫口减退率。     

川硬皮肿腿蜂携带白僵菌主动传染松墨天牛探索试验

进行了川硬皮肿腿蜂携带白僵菌主动传染松墨天牛的室内探索试验,结果表明,松墨天牛个体大小对川蜂能否成功寄生影响很大,在4龄天牛幼虫上,川蜂不能寄生;3龄幼虫中,以每头10蜂处理的寄生率达到70%,以每头5蜂处理的寄生率为40%,寄生成功后川蜂能在寄主上完成生活史。Bxs菌株对川蜂的毒力不强,可以忽略白僵菌对川蜂的毒力影响。     

释放天敌昆虫对松褐天牛的防治效果研究

在张家界国家森林公园、慈利县、韶山市、南岳区释放川硬皮肿腿蜂和花绒寄甲2种天敌昆虫,开展防治松褐天牛的试验。结果表明:2种天敌昆虫对松褐天牛有良好的控制作用,4个试验区的平均虫口减退率为92.65%,校正虫口减退率为91.41%;混合释放2种天敌昆虫的寄生率为92.42%,高于单独释放川硬皮肿腿蜂和花绒寄甲的寄生率62.00%和87.34%。     

川硬皮肿腿峰中间寄主的人工繁育技术研究

川硬皮肿腿蜂只寄生完整的活寄主,对受伤,死亡的虫体概不寄生。室内２６种寄主接蜂试验表明,对天牛幼虫及钻蛀性害虫均可寄生并繁殖出正常的子代蜂。以杉棕天牛为好,粗鞘双条杉天牛次之。     

沧州蛀干害虫生物防治技术研究

进行了川硬皮肿腿蜂对天牛的防治效果和中华甲虫蒲螨对小线角木蠹蛾的防治效果试验,结果表明:川硬皮肿腿蜂释放量80～100头/株(1管/株)的天牛被寄生率达37.65%～45.08%,平均41.70%;释放量160～200头/株(2管/株)的天牛被寄生率达40.79%～46.03%,平均43.77%;两种释放量的平均防效基本相当,总寄生率43.12%,经济释放量为80～100头/株(1管/株)。中华甲虫蒲螨释放量1～2万头/株(1管/株)的小线角木蠹蛾的防效达41.08%～46.71%;释放量2～4万头/株(2管/株)的小线角木蠹蛾防效达42.38%～48.33%;总防效在43%～46.12%,平均防效44.17%。两种释放量防效基本相当,经济释放量为1～2万头/株(1管/株)。经过2年多的观测研究,证实川硬皮肿腿蜂和中华甲虫蒲螨均可适应沧州市的自然环境和气候环境,对天牛、小线角木蠹蛾等多种蛀干性害虫均有良好的防治效果。     

川硬皮肿腿蜂中间寄主的人工繁育技术研究

川硬皮肿腿蜂ＳｃｌｅｒｏｄｅｒｍａｓｉｃｈｕａｎｅｎｓｉｓＸｉａｏ只寄生完整的活寄主,对受伤、死亡的虫体概不寄生。室内２６种寄主接蜂试验表明,对天牛幼虫及钻蛀性害虫均可寄生并繁殖出正常的子代蜂。以杉棕天牛为好,粗鞘双条杉天牛次之。     

川硬皮肿腿蜂环境适应性的初步研究

用鳞翅目幼虫８种、鞘翅目幼虫９种、膜翅目幼虫５种、双翅目幼虫２种室内接种川硬皮肿腿蜂Ｓｃｌｅｒｏｄｅｒｍａ ｓｉｃｈｕａｎｅｎｓｉｓ Ｘｉａｏ，结果表明，大部分天牛、全部膜翅目幼虫、为害枝梢的鳞翅目及处于停育期的米黑可完成发育，蝇类不能被寄生。川硬皮肿腿蜂可在２℃低温下维持生存，但适合的发育温度较高。有较强搜索能力。该蜂在冬季增温并提供适合的寄生可持续繁殖。     

川硬皮肿腿蜂环境适应性的初步研究

用鳞翅目幼虫８种、鞘翅目幼虫９种、膜翅目幼虫５种、双翅目幼虫２种室内接种川硬皮肿腿蜂ＳｃｌｅｒｏｄｅｒｍａｓｉｃｈｕａｎｅｎｓｉｓＸｉａｏ，结果表明，大部分天牛、全部膜翅目幼虫、为害枝梢的鳞翅目幼虫及处于停育期的米黑虫可完成发育，蝇类不能被寄生。川硬皮肿腿蜂可在０℃低温下维持生存，但适合的发育温度较高。有较强搜索能力。该蜂在冬季增温并提供适合的寄主可持续繁殖     

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.