蓝叶忍冬嫩枝扦插繁育技术研究

为掌握扦插基质、植物生长调节剂对蓝叶忍冬(Lonicera korolkowi)嫩枝扦插成活的影响,采用不同基质、不同植物生长调节剂种类、不同浓度、不同浸泡时间对蓝叶忍冬进行了试验研究,结果表明:蓝叶忍冬选用东北泥炭+净沙(1:2)混合作为扦插基质,在浓度为900 mg/L的ABT1号生根剂中浸泡10~20 min,扦插成活率最高。     

不同基质和生长调节剂对乡土植物扦插生根的影响*

在温室条件下,采用不同质量浓度ABT2号生根粉对蔓花生(Arachis duranensis)、碰碰香(Plectranthus tomentosa)和四季秋海棠(Begonia semperflorens)进行扦插试验,结果表明:质量浓度为100 mg/L的ABT2号生根粉溶液可以提高蔓花生的成活率;碰碰香在ABT2号生根粉为300 mg/L时比较容易生根;不同质量浓度ABT2号生根粉对四季秋海棠的生根没有显著影响,说明四季秋海棠比较容易生根.采用3种基质对天胡荽(Hydrocotyle sibthorpioides)、锦绣苋(Alternanthera bettzickiana)和铺地锦竹草(Callisia repens)进行扦插生根研究发现:天胡荽在田园土基质和泥炭土+珍珠岩基质中均有较好的生根效果;锦绣苋和铺地锦竹草均在泥炭土+珍珠岩基质中的生根效果最好.     

不同基质和生长调节剂对乡土植物扦插生根的影响

在温室条件下,采用不同质量浓度ABT2号生根粉对蔓花生(Arachis duranensis)、碰碰香(Plectranthus tomentosa)和四季秋海棠(Begonia semperflorens)进行扦插试验,结果表明:质量浓度为100 mg/L的ABT2号生根粉溶液可以提高蔓花生的成活率;碰碰香在ABT2号生根粉为300 mg/L时比较容易生根;不同质量浓度ABT2号生根粉对四季秋海棠的生根没有显著影响,说明四季秋海棠比较容易生根。采用3种基质对天胡荽(Hydrocotyle sibthorpioides)、锦绣苋(Alternanthera bettzickiana)和铺地锦竹草(Callisia repens)进行扦插生根研究发现:天胡荽在田园土基质和泥炭土+珍珠岩基质中均有较好的生根效果;锦绣苋和铺地锦竹草均在泥炭土+珍珠岩基质中的生根效果最好。     

不同处理因子对卡亚扦插生根的影响

为了优化卡亚(Cnidoscolus aconitifolius)的扦插繁殖技术,以卡亚当年生半木质化嫩枝为试验材料,探究不同生根剂种类和浓度以及不同基质对不同品种卡亚扦插生根的影响。结果表明,将卡亚插条在500 mg/L的IBA溶液中处理2 h后,扦插于基质3(椰棕∶泥炭土=3∶1)中,其生根效果最佳,生根率可达93.15%,平均根数为24.53条,平均根长为32.90 cm。'Chaya'品种有更好的生根效果。     

山茶花品种六角红在不同配比基质上的扦插试验

对山茶花品种六角红在不同配比基质上进行扦插试验,发现插穗在不同配比基质上的成活率、生根数和根长均存在极显著差异。方差分析结果表明:1)插穗在2/3黄心土+1/3腐熟松针土配比基质上的成活率最高,达92%;生根数最多,为7.20;根长最长,达10.13 cm;2/3黄心土+1/3腐熟松最适宜用于山茶花扦插。2)1/3黄心土+1/3河沙+1/3腐熟松针土也可以作为扦插基质,插穗的成活率达到84.33%。3)插穗在1/2黄心土+1/2河沙上的成活率也达80%,但生根数较少,根系不长。4)插穗在1/2黄心土+1/2草木灰和1/3黄心土+1/3草木灰+1/3河沙这2种配比基质上成活率都很低,并且生根数少,根系生长慢,不适合用作扦插基质。       

金冠柏扦插繁殖试验研究

用不同浓度、不同处理时间的ABT1号生根粉处理金冠柏插穗,扦插在1/2珍珠岩 1/2草炭土和1/2园土 1/2草炭土两种混合基质中,结果表明:质量分数3.0×10-4、处理时间4h,扦插在混合基质(1/2珍珠岩 1/2草炭土)中的金冠柏生根率达60.4%,而且生根数量较多,根的伸长生长情况也较好。     

几种绿化苗木扦插生根试验初报

扦插是绿化苗木生产中常用的种苗繁育方式,为了探索在生产上成活率较高的扦插措施,本试验以白蝉、非洲茉莉、夹竹桃为扦插材料,采用3种生根基质、以500mg/l NAA和IBA溶液速蘸插穗切口进行扦插生根试验;同时以覆盖塑料薄膜和不覆盖薄膜进行保湿处理对比。结果表明,不同苗木品种的生根成活率差异极显著;不同基质的生根成活率差异极显著,其中以耕作土加泥炭土按7：3混合的基质效果最好;500mg/l NAA和IBA溶液处理对生根没有显著作用,扦插后覆盖塑料薄膜的生根效果极显著优于不覆盖薄膜处理。     

白蝉等3种绿化苗木扦插生根试验初报

扦插是绿化苗木生产中常用的种苗繁育方式,为了探索在生产上成活率较高的扦插措施,本试验以白蝉、非洲茉莉、夹竹桃为扦插材料,采用3种生根基质,以500 mg/L NAA和IBA溶液速蘸插穗切口进行扦插生根试验;同时以覆盖塑料薄膜和不覆盖薄膜进行保湿处理对比。结果表明,不同苗木品种的生根成活率差异极显著;不同基质的生根成活率差异极显著,其中以耕作土加泥炭土按7∶3混合的基质效果最好;500 mg/L NAA和IBA溶液处理对生根没有显著作用,扦插后覆盖塑料薄膜的生根效果极显著优于不覆盖薄膜处理。     

铺地柏优良类型选择试验

通过对吉林省西部引种不同种源的铺地柏进行生长特性和抗寒性试验,结果表明:在冠幅生长量方面,铺地柏1号(内蒙古阿尔山)和铺地柏3号(河北张家口)生长量最大;分枝个数方面,铺地柏2号(黑龙江齐齐哈尔)、3号、4号(辽宁鞍山)分枝都较多;在地径比较方面,铺地柏3号3年生地径最大。通过田间抗寒性试验,在5个品种中1号和4号最不抗寒,而铺地柏2号、5号的抗寒级别分别为Ⅳ和Ⅲ,铺地柏3号最抗寒,抗寒级别为Ⅱ级。因此,铺地柏3号最适宜在吉林省西部地区栽植推广。     

蓝叶忍冬全光照喷雾嫩枝扦插试验研究

采用三因素三水平正交试验设计,开展蓝叶忍冬(Lonicera korolkowii)全光照喷雾嫩枝扦插育苗技术研究。结果表明:蓝叶忍冬属易生根树种,以皮部生根为主兼愈伤组织生根的综合型生根,插后32 d即产生爆发性生根,各处理生根率均达96%以上。对插穗生根的影响因素依次为插穗类型母树年龄ABT1号质量分数。影响生根率的最佳处理组合为A3B3C2。影响生根数量、生根长度的最佳处理组合为A1B3C2。     

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.     

Decomposition and nutrient loss from prunings of different contour hedgerow species in tea plantations in the sloping highlands of Sri Lanka

Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week⁻¹ for leaves and from 0.0225 to 0.0633 week⁻¹ for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient enrichment capacity and slower decomposition rates which would minimize leaching losses. This revised version was published online in June 2006 with corrections to the Cover Date.     

Effects of Seed Weight and Seed Type on Early Seedling Growth of Pinus sylvestris under Harsh and Optimal Conditions

The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions.     

Modelling of adequate pretwist for obtaining straight timber

Abstract

Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists.     

Potential to harness superior nutritional qualities of exotic baobabs if local adaptation can be conferred through grafting

Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral contents and B₁ and B₂ vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B₁ 88 mg 100 g⁻¹, B₂ 187 mg 100 g⁻¹, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations.     

Growth of Phlebiopsis gigantea in wood of seven conifer species

Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered.     

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。