乐氰乳油对长足大竹象的防治试验

利用农药乐氰乳油对慈竹长足大竹象Cyrtorachelus buqueti进行了室内和室外防治试验。结果表明施药浓度为300-600倍液，竹笋的成竹率从50％提高到75．9％～76．7％，显示了乐氰乳油对长足大竹象具有较好的防治效果。     

氯氰菊酯对长足大竹象的防治试验

利用农药氯氰菊酯对慈竹长足大竹象进行了室内和室外防治试验。结果表明施用浓度为1∶300~1∶600倍液,竹笋的成竹率从50%提高到87.5%~94.7%。显示了氯氰菊酯对长足大竹象具有较好的防治效果。     

溴氰菊酯防治竹笋夜蛾试验

在出笋期和虫入侵期,用2.5％溴氰菊酯乳剂1000倍液防治竹笋夜蛾2次,每亩用药2—4毫升,竹笋虫退率比对照降低79.26—88.27％,成竹率提高31.68—55.54％。防治1次虫笋退率比对改照降低78.87％;成竹率平均提高32.09％。且具有成本低、操作简便。施用安全等优点。     

淡竹林竹笋泉蝇生物学特性与防治研究初报

竹笋泉蝇(Pegomyia Kiangsuensis Fan)属双翅目花蝇科泉蝇属,主要为害竹笋,致使竹笋腐烂、发臭,不能成竹。竹笋因遭此为害,成竹率大为下降。淡竹林一般每年3代笋,2、3代笋受其为害,多不能成竹,竹笋的成竹率仅在50%左右,天长县淡竹林1563.2ha,分布在65000多户,竹林每公顷年收入6145.5元,最多可达15000元以上;据调查,竹笋泉蝇发生面积在     

一字竹象的防治

一字竹象(Otidognathus davidis Faimlaire)，主要危害毛竹、桂竹、淡竹、刚竹等竹笋，是笋期的主要害虫之一，严重发生年份竹笋受害率高达90％以上。成虫、幼虫均在笋上取食，幼虫钻蛀危害，导致笋成竹后折枝断梢，秆部虫孔累累。节间缩短，竹材变脆。     

云南甜竹、大头典竹、吊丝单竹引种栽培试验研究

介绍了华安县1998年引种云南甜竹、大头典竹、吊丝单竹3个竹种的生长情况、经济效益和栽培技术。试验结果表明，其平均造林成活率和当年出笋率为：93．3％和85．9％，造林第2年就可郁闭成林，并有竹笋产出，第3年有竹笋、竹材产出，第4年达到稳定丰产期，每亩(1hm^2＝15亩，下同)平均产鲜笋l124kg、竹材45lkg，投入产出比为1：1．8。     

文摘

1980—82年对一字竹象(Otidogna-tbus davidis F.)进行了防治试验,结果表明:每株注射0.5—1.0毫升50％甲胺磷乳油(1:3浓度)保笋率最高,成竹率95％以上,林分平均高比对照增加63.16％,竹材产量提高39.31。     

毛竹林不同经营类型的实践与效益

通过分类经营,毛竹材用林、两用林和笋用林的竹材和竹笋产量都得到较大提高,从示范基地看,到2012年,材用林竹材和竹笋产量分别达到28 755kg/hm2和3 750kg/hm2,比2008年增长71.2%和13.6%;两用林竹材和竹笋产量分别达到17 265kg/hm2和5 775kg/hm2,比2008年增长65.6%和45.8%,而2010年增长更多;笋用林的竹笋产量,2010年和2012年分别为30 570kg/hm2和23 190kg/hm2,比2008年增长62.9%和23.6%。通过分类经营,可充分发挥不同立地条件的增产潜力,增加竹材和竹笋产量,提高经济收益。因此,在立地条件较好的毛竹林,可通过笋用林经营技术,以提高竹林的经济收益。在立地条件中等的毛竹林,可适当发展两用林,特别在毛竹竹材价格下降的情况下,通过提高竹笋产量,特别是冬笋的产量,可极大提高毛竹林的经济效益。     

毛竹增产剂配方筛选及竹腔施肥效果分析

通过对毛竹林连续5a的竹腔施肥试验，分析毛竹增产剂配方中各试验因素和水平之间对毛竹新竹数、新竹平均胸径、出笋数及成竹率的影响，并对竹林竹腔施肥前、后总体效果进行比较。结果表明试验期年均水平与试验前水平相比，新竹量、新竹平均胸径、年均出笋数、成竹率分别提高了62．8％、16．9％、69．0％和17．9％。试验区与对照区相比，新竹量、新竹平均胸径、笋产量、成竹率分别提高了75．0％、15．2％、79．7％、35，2％，年均增加收益115．9％。     

丛生竹材笋两用林丰产栽培技术研究和应用专题

丛生竹材笋两用林丰产栽培技术研究和应用专题丛生竹材笋两用林丰产栽培技术研究和应用专题竹类以其年年抽笋、岁岁成竹，从笋到材广为利用而优于一般林木。当今各种竹质人造板已广泛应用于建筑、家具、车厢、包装等各个方面；竹笋、竹制工艺品及多种竹副产品也成为出口创...     

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.