麻栎容器育苗技术初探

为适应福建低山丘陵造林,在培育麻栎苗过程中采用了容器袋育苗、遮荫网、综合控根等措施,当年9月点播的容器苗次年2月出苗率可达到80%以上,苗木出圃规格达到合格苗标准。育苗次年在林冠下造林表现良好,当年造林成活率平均可达90%以上,保存率85%以上。在麻栎容器苗培育中,宜采用50%敌敌畏乳油1000倍液浸泡种子24 h、30~70%透光率遮阴网、使用修枝剪断根的物理切根辅以定期挪动容器苗采用空气切根进行控根处理。     

辽西岩质海岸侧柏造林试验

从苗龄、栽植季节、保水剂处理、根系处理等方面对辽西岩质海岸侧柏造林的栽植技术和成活情况进行了对比试验研究。结果表明:岩质海岸容器苗造林以1.5年生苗龄适宜,同苗龄容器苗造林春、夏、秋三季差异不显著;裸根苗造林前经浸水、带土坨处理可有效提高造林成活率;用保水剂处理裸根苗对提高造林成活率作用明显,保水剂的最佳使用量为200~250 g.穴-1。     

麻竹育苗和造林技术

麻竹采用主枝扦插育苗、次生枝扦插苗、带蔸根埋杆育苗等新育苗技术取得良好效果.带蔸(根)埋杆育苗效果最佳,比其他育苗方法可提高成活率38.3%—46.7%.采用扦插育苗造林比移母竹造林可提高造林成活率37.3%,育苗造林成本节省2/3.     

樟子松抗旱造林技术

樟子松是大兴安岭地带性森林植被的建群乔木树种,是半干旱风沙草原区营造防风固沙林、水土保持林,草牧场防护林和用材林的主要造林树木之一。传统造林工艺技术主要是春季裸根苗造林,因小苗失水过多,降低了造林成活率,延长了苗木的缓苗期。研究解决樟子松抗旱造林工艺技术,提高樟子松造林“三率”,扩大樟子松造林比例,加快防护林体系建设速度,意义很大。一、新工艺技术要点和试验内容、方法(一)新工艺技术要点改革传统樟子松造林工艺技术的要点是变小苗直接大面积造林的粗放经营,为小苗就近集中培育大苗的集约经营;变春季裸根小苗造林为多季带土坨大苗就近移植造林;变密植为稀植、一次成林。这样做不仅调整了育苗地与造林地生态条件差异过大的矛盾,而且采取大苗壮苗,移植时带土坨伤根很轻,根系基本完整,外生菌根不损失,为提高“三率”奠定了基础。(二)试验内容和方法本试验结合生产集中培育大苗。试验地     

提高植苗造林成活率的新措施

针对农村常见造林技术问题或失误,从提高苗子根茎比(切除胚根、断根育苗;单犁辅助起苗;土球制作;冻坨苗造林、大苗移植)、加厚树盘活土层(整地方式、规格选择与布置;蛇蜕皮整地法)、克服春栽干旱关(秋栽埋干经验;浇水栽苗技巧;覆膜保墒防晚霜经验;激素化肥泥浆蘸根;吸水材料护根)、预防根部常见病(轮作、根系消毒)4个全新角度论述提高植苗造林成活率的措施。     

甘肃宕昌樟子松容器育苗及造林技术

为提高甘肃宕昌县土壤瘠薄、干旱、高寒等立地条件差的沙土山区造林绿化,多年来进行了耐寒耐旱耐瘠薄适应性强的樟子松容器育苗与造林技术实践,发现容器育苗具有提高苗木发芽率和保存率、节约种子、造林成活率高、起苗运输方便等优点。为此,对其容器育苗技术、造林技术进行了分析研究,通过实践结果表明:采用容器育苗与造林技术能够为本地区培育优质壮苗,可提高每亩产苗量25%以上;提高造林成活率15%~20%。对确保造林提质增效、加强林业生态建设和官鹅沟5A级景区绿化具有重要意义。     

苗木容器育苗技术初探

苗木容器育苗技术是利用容器装上营养土进行培育苗木的技术,采用这种技术培育的苗木叫容器苗。容器育苗具有节约种子,可以大量培育,不受造林季节的影响限制以及造林成活率高等特点,但是这种方法成本高,技术比较复杂,通常情况下用于裸根造林不易成活的树种。     

截根菌根化育苗和造林技术

截根菌根化育苗技术是中国林科院菌根中心研究开发的林业生产先进技术 ,是林业部 1997年林业科技推广项目之一。安徽省太湖县从 1998年春季起 ,连续 3年在湿地松容器苗培育和板栗实生苗培育中大面积推广应用 ,提高了苗木的产量和质量 ,增强了苗木的抗病虫害能力 ,节约了育苗成本 ,取得了良好的经济效益。1　造林步骤国外松容器苗造林是太湖县近几年大力推广的造林新技术。在芽苗移栽过程中进行截根 ,接种菌根 ,实行菌根化育苗。其过程如下 :种子处理—催芽—营养土 (培育基质 )准备—装容器—芽苗接菌移栽—菌根化育苗管理—出圃造林。1 1　…     

苗木不同繁育方式对文冠果苗木生长的影响

以同批文冠果种子6种不同育苗技术来研究其对1a生苗木造林后生长性状的影响。结果表明:不同育苗方式对1a生文冠果苗木造林后的成活率、苗高和地径影响均为极显著,且三者间均存在着极显著的正相关关系;RPM容器苗成活率(87.00%)显著高于裸根苗(30.00%),而苗高(50.73cm)、地径(7.96mm)显著高于无纺布容器苗和裸根苗;GGR处理裸根苗效果显著,成活率提高110.43%,苗高提高95.56%。     

太行山区黄连木大规格容器苗造林成效对比试验研究

采用黄连木播种大规格塑膜容器育苗与大田裸根育苗的造林对比试验结果表明,2月底种子播入13cm×20cm的大规格容器内培育苗木120d,7月雨季上山造林,成活率比1年生大田裸根苗春季造林提高30%以上。     

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.