野皂荚种子催芽技术研究

野皂荚(Gleditsia microphylla)种子具有坚硬的种皮,自然状态下不易发芽。通过对其种子进行酸蚀处理(用浓度为98%,75%,50%的浓H2SO4分别酸蚀15 min,25 min,35 min,45 min)和高温水浴处理(恒温50℃,70℃,90℃条件下分别水浴5 min,10 min),测定其发芽率、发芽势、吸涨率。试验结果表明:采用98%浓H2SO4酸蚀野皂荚种子25 min,萌发效果最佳,发芽率、发芽势和吸涨率分别为86%,73%,100%.采用恒温水浴的方法处理野皂荚种子,发芽率均≤50%,萌发效果不理想。     

浸种处理下无患子苗期生长差异分析

以普通母树上采摘的无患子种子为试验材料,对其进行9种不同的浸种处理,即不同温度的温水（40℃、50℃、60℃）、不同浓度CuSO4+H2SO4（20%、30%、40%）溶液和HCl溶液（3%、5%、8%）,探讨不同浸种方式和水平对无患子幼苗生长的影响。结果表明：温水浸种处理下无患子幼苗的生长表现较好,40℃温水浸种明显提高幼苗苗高的生长,50℃浸种处理次之;60℃温水浸种处理对提高无患子幼苗地径生长速度在9组浸种处理中表现效果最为良好;CuSO4+H2SO4溶液和HCl溶液对无患子的苗期生长影响差异显著。综合比较,温水是促进无患子幼苗生长的最佳浸种处理方法。     

不同处理对久树种子发芽的影响

在 2 6℃的条件下进行培养 ,去皮处理可显著提高久树种子的发芽率 ,较对照提高 31.7%。ABT4号生根粉在久树育苗试验中 ,可有效地促进久树种子出苗率和成活率 ,浸种浓度在 2 5mg·kg- 1时 ,发芽率、发芽势、平均发芽时间都较对照有明显的提高。F检验证明光照处理的久树种子较遮光处理发芽效果好 ,证明久树种子对光敏感     

硫酸-离子液体复合催化剂催化松香聚合反应工艺的研究

首次将3种硫酸-离子液体复合催化剂[H2SO4-（C2mim）BF4、H2SO4-（C4mim）BF4和H2SO4-（C8mim）BF4]用于催化松香聚合反应中，H2SO4-（C4mim）BF4和H2SO4-（C8mim）BF4均显示出很好的催化活性。以H2SO4-（C8mim）BF4为代表，详细考察了不同溶剂、H2SO4用量、反应温度和反应时间等因素对反应结果的影响，得到较佳的工艺条件：松香和甲苯质量比1：1，催化剂用量为松香质量的30％．反应温度70℃，反应时间4h。在该条件下，得到的聚合产物软化点为135℃，酸值为142mg/g并对H2SO4-（C8mim）BF4复合催化剂的重复使用性能进行了考察，该复合催化剂克服了传统催化剂的一些缺点，既简化了产物的分离。又可以重复使用。     

硫酸-离子液体复合催化剂催化松香聚合反应工艺的研究

首次将3种硫酸-离子液体复合催化剂[H2SO4-(C2 mim)BF4、H2SO4-(C4 mim)BF4和H2SO4-(C8mim)BF4]用于催化松香聚合反应中,H2SO4-(C4 mim)BF4和H2SO4-(C8mim)BF4均显示出很好的催化活性.以H2SO4-(C8mim)BF4为代表,详细考察了不同溶剂、H2SO4用量、反应温度和反应时间等因素对反应结果的影响,得到较佳的工艺条件松香和甲苯质量比11,催化剂用量为松香质量的30%,反应温度70℃,反应时间4 h.在该条件下,得到的聚合产物软化点为135℃,酸值为142mg/g.并对H2SO4-(C8mim)BF4复合催化剂的重复使用性能进行了考察,该复合催化剂克服了传统催化剂的一些缺点,既简化了产物的分离,又可以重复使用.     

不同处理方式对黑莓‘Kiowa’种子发芽的影响

研究了7种不同化学药剂结合不同时间的低温层积处理后黑莓‘Kiowa’品种种子的萌发特性,探索打破种子休眠的有效方法。结果表明,对种皮具有软化或腐蚀作用的NaClO、浓H2SO4和H2O2对黑莓种子发芽具有明显的促进效应,而GA3、PEG6000、KNO3、NaOH促进效果不明显,表明种皮障碍是影响其萌发的主要因素,而且以20%NaClO的处理发芽率最高。低温层积时间越长越好,以90～120天为宜。以NaClO处理并低温沙藏90天的种子发芽试验表明,不同浓度NaClO处理的种子发芽率在萌发过程中均呈现先急剧增加再缓慢增加直至恒定的趋势,其中以培养20天时达到高峰期。     

微乳凝胶固定化单宁酶催化没食子酸酯的合成

没食子酸酯是一类优良的抗氧化剂,为了避免化学合成方法带来的弊端,建立了微乳凝胶(MBGs)固定化单宁酶催化系统,催化没食子酸(GA)与不同的脂肪醇进行酯化.Na2SO4-Na2SO4·10H2O盐水合对可有效调控有机相固定化酶催化系统中水的活度,其调控能力与盐水合对的总量有关.在反应系统中加入盐-盐水舍对(Na2SO4-Na2S04·10H2O)可以明显提高GA的转化率.当pH值6、温度28℃、振摇速度150 r/min时,在生产没食子酸丙酯(PG)、没食子酸丁酯(BG)的MBGs反应系统中,加入总量1.8 g,比例为1:1的Na2SO4-Na2SO4·10H2O,GA的转化率可分别达到78.2%和85%,比对照样分别提高93.0%、129.7%;在生产没食子酸戊酯(AG)的MBGs反应系统中,加入总量2.4 g,比例为1:1的Na2SO4-Na2SO4·10H2O,GA的转化率为72.4%.比对照样提高103.7%.     

促进圆叶乌桕发芽的种子处理技术研究

圆叶乌桕[Triadica rotundifolia(Hemsl.)Esser]是石灰岩地区次生林特有树种,该树种树形优美,叶形独特,秋季落叶前变红,是石灰岩山地极具应用前景的风景林树种。报道了不同种子处理方式对圆叶乌桕种子发芽率、发芽势和发芽势的影响。结果表明,应用98%H2SO4处理种子2min后清洗播种可显著提高圆叶乌桕种子的发芽率、发芽势和发芽指数,其它酸、碱、温水和人工破损种皮等处理方法虽然可提高种子的发芽率、发芽势和发芽指数,但效果不佳;90℃热水浸泡到自然冷却和10%硫酸处理种子12h等处理会直接伤害种子,因此种子萌发率低。该研究成果可为圆叶乌桕的开发利用及播种育苗工作提供参考资料。     

濒危植物丽豆播种育苗试验

采用不同催芽处理方式,对濒危植物丽豆进行了播种育苗对比试验,观测了1年生、2年生苗的生长量、生物量与生长节律,得出:采用70%～90%的H2SO4液及GGR液处理种子时间短,效果最佳;全年苗高和地径生长量集中在4月至7月;1年生苗木生物量较小,2年生苗木生物量急剧加大.     

及其催化合成乙酸松油酯的研究

用几种稀土元素对单一型固体超强酸SO2-4/TiO2进行改性.结果表明,用Ce4 改性效果较好,且当Ce4 质量分数为7.5 %、经500 ℃焙烧3 h后催化剂SO2-4/TiO2-Ce4 的催化活性最佳,并用TEM、XRD和IR对其结构进行了表征.该改性催化剂属于纳米级材料,粒径为32 nm,粒度均匀.并以该固体超强酸SO2-4/TiO2-Ce4 为催化剂,松油醇和乙酸酐为原料合成乙酸松油酯.利用正交试验得到适宜的合成条件为:反应温度70 ℃、催化剂用量3 %、松油醇与乙酸酐物质的量之比为1∶1.5、反应时间6 h.在此条件下,松油醇转化率达99 %,产物中乙酸松油酯含量达90 %.与普通型固体超强酸进行比较,SO2-4/TiO2-Ce4 具有更高的催化活性和选择性.     

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.