植物激素提高金丝小刺座果率和产量试验

在金丝小刺励花期喷布不同浓度的三种植物激素，结果表明１０＊１０＾－６赤霉素和新郑座果一号，对提高金丝小枣座果率和产量效果最好。     

83008—1在无花果中的作用

８３００８－１是一种新型的植物生长调节剂，用不同浓度的８３００８－１对无花果进行田间试验，结果表明：５０×１０－６促进顶端生长，２００×１０－６明显地抑制顶端生长；１００ｘ１０－６对座果数、单果重有促进作用．在１００×１０－６的基础上，添加一定量的氮和磷，单果重明显提高．     

“柱型”腐殖酸复混雪花梨专用肥在沙地的应用研究

１９９６年在对４种不同本比的“柱型”腐殖酸复混肥常规施肥的产量、叶绿素含量和叶片磷、钾含量进行了比较。其结果表明，“柱型”肥料比常规施肥的产量增加１５．３８－２３．４２％，叶绿素含量提高了６．６－１４．６％；在果实膨大期“柱型”肥料处理的叶片中磷、钾含量分别比常规对照提高了２７１－２７８％和６．１％－１０．５２％。１９９７年，用改进氮、磷、钾含量后的新配方肥料在相同的雪花梨上进行了试验，对产量的检     

克线磷防治松材线虫病的研究

为防治松材线虫病，１９８８－１９９２年间，使用３种药剂对松材线虫（Ｂｕｒｓａｐｈｅｌｅｎｃｈｕｓｘｙｌｏｐｈｉｌｕｓ）进行室内毒性测定，并选用５％克线磷颗粒剂在林间、盆栽树苗上作防治试验．巴丹在１００×１０－６时，线虫仍可存活、繁殖；Ｆ—００１药剂在５０×１０－６以上时，灭虫率均可达９０％以上，克线磷浓度在６０×１０－６以上时，则可完全抑制线虫的生长繁殖．在林间，以克线磷处理的黑松（Ｐｉｎｕｓｔｈｕｎｂｅｒｇｉｉ）植株，均比对照株死亡率低．盆栽苗上的施药、接种试验，更进一步证实了该药剂的防病效果．     

松毛虫质型多角体病毒围栏增殖技术

病毒围栏增殖方法由云南省林科院经过１０年多病毒复制试验证明，该方法是增殖ＣＰＶ用以防治松毛虫最经济实用的方法，其病毒投入少，产量高，风险较小。设置围栏采集６－７龄文山松毛虫幼虫，选用１＊１０＾７ＣＰＢ／ｍＬ的病毒感染浓度，接种后１３－１５天回收，感病虫回收率可害８０％以上，     

柳毒蛾核型多角体病毒杀虫剂林间防治试验

多点小面积和大面积防治试验证明，由室内及林间增殖的ＮＰＶ配制病毒制剂防治柳毒蛾幼虫是有效的。一旦将病毒引入林内，即可引起流行病发生并导致柳毒蛾密度锐减。其喷洒剂量在６．０×１０＾１１－７．５×１０＾１１ＰＩＢ／ｈｍ＾２，最高不超过１．５×１０＾１２ＰＩＢ／ｈｍ＾２。防治适期应在３－４龄幼虫占８０％左右时为宜，了可提前在２－３龄幼虫占８５％左右时进行。喷洒时间在１６：００以后为好。     

拟异尾华枝Xiu的取食量研究

拟异尾华枝Ｘｉｕ Ｓｉｎｏｐｈａｓｍａ ｐｓｔｕｄｏｍｉｒａｂｉｌｅ Ｃｈｅｎ雌、雄性的个体取食量：雌性一生总食叶量为１７．８８ｌｇ，其中１－４龄低龄若虫期的占５．４８％，５－７龄老龄若虫期的占２２．７１％，成虫期的占７１．８１％；雄性为７．２１５ｇ，其中１－４龄低龄若虫期的占６．２０％，５－６龄老龄若虫期的占３１．１０％，成虫期的占６２．７０％，老龄若虫期和成虫期是主要的危害期；并分别建立了雌、     

我国寒温带地区哺乳类物种多样性及现状

１９８８～１９８９年，１９９３～１９９５年，两次对我国寒温带哺乳类物种多多样进行地调查研究，结果表明，该区共有５６种兽类，分属６目，区系特点表现了泰加林群落的特征，北方型和东北型兽类相混杂，啮齿类种类占优势，食虫类和翼手类较少，由于地人类活动的影响，５５．３６×１０＾－２的物种下降或分布区缩小或处于濒危，灭绝，２８．５７×１０＾－２物种种群尚能保持稳定，１６．０６×１０＾－２的物种种群数量增加，受     

塞罕坝人工针叶林中鸟类调查研究

为了解塞罕坝的鸟类资源状况，１９９２－１９９５年在塞罕坝人工针叶林中用条带统计法，对各季节鸟类密度进行估计，共记录鸟类８目２０科７３种，其中留鸟１７种，占总数的２３．２９％，各季节平均密度１３．１１只／１０ｈｍ＾２；夏候鸟４０种，占５４．７９％，平均密度为２１．５０只／１０ｈｍ＾２；冬候鸟６种，占８．２２％，平均密度２．２９只／１０ｈｍ＾２，旅鸟１０种，占１３．７０％，平均密谋２．６８只／１０ｈｍ     

英德跳(虫脩)生物学特性和防治研究

英德跳ｘｉｕ是我国森林昆虫竹节虫目的一新虫种。在广东省英德县效益发现危害黎蒴栲林成灾得名。若虫和成虫危害黎朔栲为主的壳斗科树叶，以成虫危害最烈。该虫在英德县１ａ发生２－３代，世代重叠。以第１、２代成虫产的卵在枯枝落叶层下越冬，翌年２月下旬开始化，５月中、下旬为越冬代成虫高峰期。在５月下、中旬使用３％６６６烟剂１５ｋｇ／ｈｍ＾２防治，效果达８５％以上；使用绿僵菌１．５×１０＾３个／ｍｈ＾２孢子防治，     

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.