工厂化单损伤培育腾冲红花油茶本砧嫁接苗技术

无性繁殖技术一直是制约腾冲红花油茶产业发展的瓶颈。通过试验总结形成的工厂化单损伤幼砧嫁接技术,与芽苗砧嫁接技术比较,其工效、成活率相近,但嫁接成活后抽梢率、1年生苗木生长量明显优于后者,并有效解决了芽砧嫁接砧、穗不遇的难题。该技术发明为腾冲红花油茶无性繁殖提供了一种重要的繁殖手段。     

香榧实生大苗嫁接技术试验

以地径3～4cm的实生香榧大苗为砧木、‘细榧’等品种为接穗,研究不同嫁接方法、嫁接时间、接穗类型及是否剪砧、是否采取防晒措施对香榧新梢生长和嫁接成活率的影响.结果表明,采用贴枝接和劈接的嫁接成活率分别为90.58％和76.67％,达到5％显著水平,贴枝接的新梢抽生数、新梢个数、新梢生长量也略高于劈接;2月29日(2012年)至3月22日嫁接,嫁接成活率间没有显著差异,但新梢生长量随嫁接时间推迟而减小;1年生新梢上段和半木质化嫩梢作接穗的成活率均达到85％以上,1年生接穗粗度对嫁接成活率没有明显影响,但接穗越粗,新梢生长量越大,1年生枝条下段和2年生接穗嫁接成活率较低;第1年不剪砧的嫁接成活率高于剪砧,但剪砧新梢生长量大于不剪砧;对嫁接枝用箬叶包扎进行防晒对提高嫁接成活率没有作用.     

腾冲红花油茶芽砧嫁接苗培育技术

为解决腾冲红花油茶嫁接成活率低、成本高和大规模产业化苗木培育问题,总结出采用芽苗作砧木和半木质化枝条作接穗的嫁接苗培育技术,嫁接成活率可达到80%以上,且能够形成大规模生产。     

榆林沙区彰子松嫁接彰武松技术试验研究

采用多个单因素试验,对榆林沙区樟子松嫁接彰武松在接穗、砧木及接后管理措施等方面对嫁接成活率的影响进行了研究,结果表明:接穗粗度为0.5~0.6cm成活率最高、为92.3%,接穗长度为8~10cm成活率最高、为82.2%,3~4a生砧木嫁接成活率最高、为93.7%,冷水冷藏与冷库冷藏相比嫁接成活提高26.5百分点,接后采取灌溉措施嫁接成活率高9.8百分点、新梢生长量增加16.4cm,本地接穗成活率与引种地接穗差异不显著,但成本仅为为引种地30.24%,生产中可参考这些结果进行嫁接。     

蓝莓高接换种技术研究

为探索蓝莓高接换种技术,试验以6年生的夏普蓝莓作砧木,奥尼尔、灿烂、顶峰等3个蓝莓品种的枝条为接穗,研究嫁接季节、嫁接天气、接穗来源部位对高位嫁接的成活率和接穗抽梢生长量的影响。结果表明,春、秋2个季节嫁接的成活率无显著差异,接穗新抽梢生长量春、夏、秋3个季节之间存在极显著差异,秋季最差,夏季(6月)嫁接并加以保湿、遮阴,可有效提高嫁接成活率,利用早、中熟品种的修剪枝进行嫁接不影响蓝莓当年产果量,且新梢能明显加快嫁接植株的生长发育进程,第2年即可开花结果;不同天气嫁接的成活率存在极显著差异,晴天嫁接最好,接穗新抽梢生长量无显著差异;不同接穗来源部位嫁接的成活率和接穗新抽梢生长量,存在极显著差异,中部接穗最好。因此,选取枝条中部接穗在夏季(6月下旬)晴天嫁接为蓝莓最佳的高接换种方法。     

榆林造林地红松高枝嫁接对比试验

为了探索影响樟子松嫁接红松成活率及新枝生长量的因素,通过选取不同砧木规格、不同接穗储藏方式和不同嫁接方式进行高枝嫁接试验。结果表明:不同砧木规格下,砧木高度为183cm的嫁接成活率达到88.88%,新梢生长量为18.20cm,显著高于砧木高度为153cm和228cm;不同接穗储藏方式下,冰柜储藏方式的成活率和新梢生长量分别为91.17%和16.33cm,显著高于沙藏;不同嫁接方法下,芽接的成活率和新梢生长量分别为96.1%和19.27cm,显著高于对接方法。表明不同砧木规格、接穗储藏方式和嫁接方式对红松嫁接成活及生长特性具有显著影响。     

红花油茶嫁接育苗试验研究

对红花油茶嫁接的成活率和抽梢率进行了对比试验,对砧木年龄、嫁接高度、穗条不同留叶量和接穗不同枝段等进行了单因素分析。结果表明:采用1年生砧木、距基部嫁接高度为4cm、接穗留有1个叶片和取第2～3枝段接穗条进行嫁接,育苗效果较好。     

不同接穗类型对红松嫁接成活率及生长势的影响

探讨了不同接穗采集时间、不同接穗采集部位、不同采穗母树年龄对红松嫁接成活率及生长势的影响。结果表明:接穗最佳采集时间为嫁接当年2月份左右,2月5日、15日和25日采集的接穗成活率分别为86.7%、89.3%和89.3%,接穗年生长量也显著高于上年12月份采集的种穗;最佳接穗的采集部位为母树的上部、中部,嫁接成活率分别为88.2%和88.9%,接穗年生长量和接穗直径也显著高于下部接穗;最佳采穗母树年龄为30～40 a,嫁接成活率分别为89.2%和88.6%,接穗年生长量和接穗直径与50年生母树接穗无显著差异。     

嫁接方法对香榧接穗成活和新梢生长的影响

为了提高香榧接穗嫁接成活率和新梢生长量,以培育3a的当地榧树实生苗和诸暨枫桥的香榧枝条为材料,分别于2019,2020年3月进行香榧苗木嫁接试验,当年10月下旬统计劈接、切接、插皮接、贴枝接4种嫁接方法的接穗嫁接成活率、测定年新梢长度和基径.结果显示,嫁接方法对嫁接后接穗成活率有极大影响,4种嫁接方法的接穗嫁接成活率最高的是插皮接(2 a平均成活率为92.80％),比最低的贴枝接(2 a平均成活率为58.18％),提高34.62％,达极显著差异(P=0.0001).插皮接新梢基径、新梢生长量最高,分别为4.57 mm,22.29 cm,新梢基径最低的是劈接4.45 mm,新梢生长量最低的是切接21.44 cm,贴枝接的新梢基径和新梢生长量均居于第3,不同嫁接方法之间,新梢基径、新梢生长量虽有差异,但差异不显著(P>0.8462).因此,采用嫁接技术培育无性繁殖的香榧苗时,应优先考虑插皮接方法,然后再考虑用切接法或劈接法.     

祁连山高寒干旱区良种杏嫁接对比试验研究

通过采取温室内早春嫁接、初夏移栽建园、大田内嫁接培植和园内砧木高接换优等不同嫁接模式、不同栽培条件、不同接后管理技术措施进行对比试验、定期观测和定量分析,结果表明:接蜡速蘸全封处理接穗,7号ABT生根粉浸泡接穗削口,温室内早春嫁接换床、初夏移栽建园模式嫁接成活率为98%,愈合时间为12d,嫁接苗当年新梢最大生长量为181cm,平均生长量为131cm,粗度1.3cm;接蜡速蘸全封处理接穗,7号ABT生根粉浸泡接穗削口,大田直接嫁接的幼树成活率为94%,接穗保鲜时间达60d以上,嫁接苗当年新梢最大生长量为162cm,平均生长量为108cm,粗度1.1cm。     

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.     

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.     

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.     

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。     

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.     

Growth of Mixed Birch-Coniferous Stands in Relation to Pure Coniferous Stands at Similar Sites in South-eastern Norway

Mean age, mean and top heights and yield were studied in 20 mixed stands of birch ( Betula pubescens Ehrh. and B. pendula Roth) and Picea abies (L.) Karst. and nine mixed stands of birch and Pinus sylvestris L. in south-eastern Norway. Each mixed stand and the adjacent pure coniferous stand (control) were growing under the same site conditions and had not been commercially thinned. There were no significant differences in mean age at breast height or in top heights between birch and conifers in the mixed stands, while mean height was significantly higher for birch than for spruce. A growth index was calculated based on total volume and age at breast height. For the spruce sites the growth in young mixed stands (birch < 17 m) was superior to that of pure spruce, while the difference was insignificant in older stands. The growth index correlated positively with the ratio between generatively and vegetatively regenerated birch trees, and negatively with the age of the oldest species in the mixture and with site quality. For the pine sites there was no significant difference in the growth index between mixed birch-pine and pure pine stands. A mixture effect of birch on the volume yield of spruce or pine could not be demonstrated.     

Defoliation by the Needle-shortening Pine Gall Midge,Thecodiplosis brachyntera,on Pines in Central Sweden

An outbreak of the needle-shortening pine gall midge, Thecodiplosis brachyntera , occurred on Scots pine, Pinus sylvestris (L.) and lodgepole pine, P. contorta (Dougl.) in central Sweden during 1995-1998. The larval feeding of T. brachyntera kills current-year needles and heavy infestation causes severe defoliation. A pattern of fluctuating defoliation among years and sites was found on both pine species. Defoliation was evenly distributed in the crown of P. sylvestris during years of high as well as low infestation; apical whorls had as much defoliation as basal whorls. In P. contorta , however, there was a tendency for defoliation to be concentrated on branches in the most apical whorls. Growth ring increments on P. sylvestris with high levels of defoliation (71%) did not differ from trees with moderate levels (26%) of defoliation. Shoot lengths were significantly shorter, however, on heavily infested trees the year after defoliation.