桂花嫩枝扦插繁殖技术试验

2013年6月在福建邵武市苗圃对桂花进行了当年生半木质化嫩枝扦插繁殖试验。采用不同生根促进剂、不同浓度,以及不同扦插基质处理。6个月后结果表明:桂花的嫩枝扦插生根率有显著差异,生根数量及根长等生根性状未达显著差异水平;桂花嫩枝扦插较佳的处理组合是:ABT3号生根剂,质量浓度为250 mg·L-1,生根率达90.0%;桂花在不同扦插基质条件下,生根率以2号基质(黄心土70%+河沙30%(体积比))较好。     

巴戟天扦插及林下栽培试验

选取巴戟天当年生半木质化藤蔓和2年生木质化藤蔓作插穗;插穗经50、100、150 mg·L^-1的NAA、IBA、ABT生根粉浸泡4 h后,扦插于黄心土、1份黄心土+1份河沙(等体积配比,下同)、1份黄心土+1份泥炭土+1份河沙的基质中,扦插60 d后统计生根率。以1年生扦插苗进行林下栽培试验,并连续4年调查其生长量。结果表明：以黄心土、1份黄心土+1份河沙、1份黄心土+1份泥炭土+1份河沙为基质扦插巴戟天,其扦插生根率分别为65.51%、72.62%、74.35%。以1份黄心土+1份河沙、1份黄心土+1份泥炭土+1份河沙为基质,其扦插生根率均显著高于(P<0.05)以黄心土为基质的。以不同浓度的3种植物生长调节剂处理的扦穗,其生根率比对照(清水)的均有显著提高(P<0.05)。3种植物生长调节剂中,以ABT处理的插穗生根效果最好;以IBA处理的插穗生根效果次之,但优于以NAA处理的。插穗的木质化程度对巴戟天扦插生根率有极显著影响(P<0.01),木质化插穗的扦插生根率极显著高于半木质化插穗的。以50 mg·L^-1的ABT生根...     

基质和植物生长调节剂对大红花扦插生根的影响

为了筛选出适宜大红花Hibiscus rosa-sinensis扦插的培养条件,研究选择黄心土、轻基质、泥炭土、混合土(黄心土:轻基质:泥炭土=2:4:4)4种基质, ABT、 IBA和NAA3种植物生长调节剂,250 mg/L、500 mg/L和750 mg/L3种质量浓度进行试验。结果显示,混合土基质扦插的大红花根系数量、根长、生根率及根系效果指数分别为3.86个、5.82 cm、87.50%和1.84,显著优于黄心土、泥炭土、轻基质(P<0.05);750 mg/L的ABT在根系数量、根长、生根率、根系效果指数4个方面均达到最大值,分别为5.06个、6.54、87.89%和2.68,是最适宜大红花扦插的植物生长调节剂和浓度;试验结果表明,大红花扦插生根率最高的处理为以黄心土为基质,750 mg/L的ABT激素速蘸30 s。研究探明了不同基质类型、不同植物生长调节剂种类及浓度梯度下大红花穗条扦插苗生根率及根系发育差异。     

基质和生根剂对火力楠扦插生根的影响研究

为探讨不同基质、不同生根剂以及同一生根剂在不同浓度下对火力楠Michelia macclurei扦插繁育的影响,研究采用3种浓度水平的ABT溶液(800、500和333 mg/kg)处理火力楠穗条,分别以3种基质(100%黄心土、100%泥炭土和65%泥炭土+25%木糠+10%珍珠岩)进行扦插,比较不同浓度生根剂和基质组合中插穗的生根率,并检测了ABT、赤霉素和根太阳3种生根剂对火力楠穗条的促生根效果。结果表明,基质类型和ABT浓度水平对火力楠插穗的生根有显著影响,但这两个因素之间的交互作用不显著,其中最佳扦插基质为黄心土,低浓度的ABT溶液的促生根效果优于高浓度,但与空白对照相比,3种生根剂对火力楠插穗生根均无明显的促进作用,即研究所选取的火力楠家系扦插繁育无需使用外源激素促进生根,可选用黄心土为扦插基质,但如何进一步提高扦插生根率仍需进一步研究。     

福建紫薇扦插基质配方灰色关联分析

以泥炭土、黄心土、细砂和珍珠岩为基质成分,设计了14种不同的配方,应用灰色关联分析方法探讨不同基质配方与福建紫薇扦插生根效果的关系。结果表明,不同基质配方的生根效果有显著的差异,以泥炭土(33.3%)+黄心土(33.3%)+细砂(33.3%)生根效果最好,生根率达89.3%。灰色关联分析表明,泥炭土有利于提高福建紫薇扦插生根率,细砂有利于增加扦插生根条数,黄心土有利于提高扦插生根长度。     

钟花樱扦插繁育研究

比较不同基质、不同生根促进剂及其质量体积浓度、不同季节、不同修剪方式、不同插穗类 型对钟花樱（Cerasus campanulata）扦插生根的影响,结果表明：扦插基质类型、生根激素种类及其质量 体积浓度、扦插季节、插穗留叶面积以及插穗类型均对钟花樱扦插成活率和生根率产生显著或极显著影 响,扦插基质采用黄心土最有利于生根;生根激素种类及其各浓度处理效果均显著高于清水对照,其中 采用IBA 以质量体积浓度2 500 mg · L-1 速蘸10 s 处理效果最佳;于春季扦插最好;插穗留1 片或半片叶 片成活率及生根率远高于不留叶插穗;采用嫩枝扦插和带踵扦插优于硬枝扦插。因此钟花樱扦插宜在春 季,采用修剪成1 片或半片叶片带踵或嫩枝的插穗,经质量体积浓度2 500 mg · L-1 的 IBA 药液蘸10 s 后 扦插在黄心土上,生根效果最好。     

不同基质对巨桉扦插生根的影响

实验选取3种不同扦插基质组合(河沙与黄心土1:1混合基质、珍珠岩与泥炭土1:1混合基质、泥炭土与黄心土1:1混合基质)对巨桉进行扦插试验.结果表明,不同的基质组合对巨桉扦插生根有很大的影响.在泥炭土与黄心土1:1混合基质中,硬枝扦插和嫩枝扦插的效果都是最好的.硬枝扦插的生根率为45％,在另两种基质组合中进行硬枝扦插不能生根;3种基质组合中,泥炭土与黄心土混合基质、河沙与黄心土混合基质、珍珠岩与泥炭土混合基质上嫩枝扦插的生根率分别为43.25％,9％、7.9％.     

缅甸树萝卜扦插繁殖技术研究

通过采用不同的留叶数目、 ABT1 号质量体积浓度、 100 mg/L ABT1 号处理时间以及扦插基质 等因素对缅甸树萝卜（Agapetes burmanica）枝条进行扦插繁殖对比试验,结果表明：（1）留 3~5 片叶的 枝条生根率最高,为 46.7%;（2）缅甸树萝卜枝条的生根率随 ABT1 号质量体积浓度的增加呈现先升高然 后下降的趋势,质量体积浓度为 100 mg/L 时,生根率最高,达 46.7%;（3）通过速蘸 100 mg/L ABT1 号 10 s、 10 min 和 1 h 处理插穗,插穗生根率分别为 26.7%、 46.7%、 40.0%,其中 100 mg/L ABT1 号浸泡插 穗 10 min 生根率最高;（4）缅甸树萝卜枝条在 V 珍珠岩： V 蛭石： V 树皮 =1:1:1 和水苔两种扦插基质中的生根 率分别为 30.0% 和 46.7%,表明水苔较适宜缅甸树萝卜的扦插生根。将缅甸树萝卜生根插穗进行移栽,成 活率可达 81.0%。     

不同激素和基质对粤海竹柳扦插生根的影响

分别以黄心土和河沙为育苗基质,比较研究了IBA(吲哚丁酸)、NAA(α-萘乙酸)及其混合液(IBA+NAA)处理对粤海竹柳插穗在不同基质上的生根效果。结果表明,3种激素处理均可促进插穗的萌芽和生根,30d时黄心土基质的插穗萌芽率为53%~76%,生根率为67%~82%,IBA处理组的萌芽率最高,NAA处理组的生根率最高,均显著高于对照组;沙基质的插穗萌芽率为60%~76%,生根率为73%~90%,混合液组的萌芽率和生根率最高,均显著高于对照组。双因素分析结果反映了基质和激素对粤海竹柳插穗的生根数、根长和根系效果指数均有显著的影响,在河沙基质培养条件下,应用体积比1∶1的IBA和NAA混合液处理的扦插生根率和生根效果最佳;在黄心土基质培养条件下,应用NAA处理的扦插生根率和生根效果最佳。     

蒜香藤的扦插育苗试验

对蒜香藤进行GGR6号不同浓度(300、500、700、1 000mg/L)处理及不同基质(纯黄心土、50%黄心土+50%细沙、细沙)的扦插试验,结果显示以细沙作为扦插基质,用浓度为300mg/L的GGR6号生根粉速蘸后扦插,生根率可达90%。     

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。     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.