丛生竹的引种繁殖及栽培技术研究

通过10余年来的丛生竹引种、育苗和造林试验得出：丛生竹走母竹育苗，以苗繁苗、竹苗造林来扩大和发展江西省丛生竹之路是行之有效的。并筛选出了适合江西省东西部栽植的丛生竹优良品种有黄竹、坭竹，青皮竹、绿竹、梁山慈竹。赣南地区除上述竹种外，还适合栽植的有粉单竹、大头典竹、吊丝单竹、吊丝球竹、吊丝竹、撑绿竹等10多个丛生竹种。     

介绍丛生竹的几种主要育苗方法

在毛主席革命路线指引下,我省广大贫下中农积极响应毛主席“竹子要大发展”的伟大号召,近几年来引种青皮竹、撑篙竹初获成功。为了解决大力发展青皮竹、撑篙竹时种源不足的困难,各地都开展了丛生竹育苗方法试验。现将我们的实践和各地群众有关青皮竹、撑篙竹的主要育苗方法作一介绍。一、竹节育苗竹节育苗是青皮竹的主要育苗方法。具体做法是,在竹丛中选择生长正常,围径5厘米左右的二年生竹(一、三年生竹成活率低),平地面将竹竿砍下,剪去梢头几个细弱的竹节,再把竿上各节的侧枝贴基部剪     

福建省北部山区优良纸浆竹种引种试验

介绍了邵武市引种撑绿竹、硬头黄竹、坭竹、单竹、青皮竹及大眼竹的成活率、出笋率等生长情况,并就福建省北部山区纸浆竹林苗圃基地建设有关问题进行了探讨。     

海南竹子育苗技术初探

依据2002年定安竹示范苗圃在育苗过程中总结出的经验和教训，结合丛生竹育苗技术的基础理论，针对海南的生境条件，以粉单竹、青皮竹和甲竹为例，对几种竹子育苗方法(包括埋蔸育苗、埋节育苗和分株育苗法)作了初步总结。目的在于为日益发展的海南竹产业生产提供参考。     

福建省北部山区优良纸浆竹种引种试验初报

介绍了邵武市引种撑绿竹、硬头黄竹、坭竹、单竹、青皮竹及大眼竹的成活率、出笋率等情况,并就福建省北部山区纸浆竹林苗圃基地建设有关问题进行了探讨.     

广东丛生竹引种育苗初报

遵照毛主席“竹子要大发展”的伟大教导,1974年3月我圃从广东顺德县引进丛生竹三个品种,共计6220株(共中青皮竹1849株;撑篙竹2062株;尼竹2309株)进行育苗试验。据6月份调查测定,三个品种丛生竹成活率都在90％以上,每株竹苗出笋4—6株,生长情况良好。现在新竹一般高3—4米,最高的达5米。直径一般达2厘米左右,其中青皮竹最大的达2.1厘米,撑篙竹达2.5厘米,尼竹达2.8厘米。一年来的育苗实践,我们主要抓了以下几个方面:     

青皮竹育苗管理

青皮竹是一种浅根性丛生竹,产于广东。它具有质量好、竹节平滑、篾性坚韧、生长迅速、繁殖力强等优点。栽植后3、4年即可砍伐利用。是编制和修理农家具、渔业用具和造纸等的上等原料,是解决目前用竹困难的有效途径。我圃1972年3月从广东引种了青皮竹4,000株进行育苗,长势良好(见图),一般每株竹苗分蘖4-6株,最多的达14株。株高2.3-2.7米,竹杆直径1.5-2厘米,成活率87.7%。在实践中我们体会到,主要抓好以下几个方面:     

丛生竹带秆留节插枝创新育苗试验及造林初报

利用丛生竹地上部分的竹秆和枝条，通过人工整理和GGR处理，实行选竹枝、带竹秆、留竹节、竹筒灌水保温等一系列操作进行育苗。通过小型和中型育苗试验，得出坭竹、绿竹等多分枝、竹壁厚、体形较大的竹种采用此法育苗效果好，育苗成活率达85％以上，发笋成竹率达70％，每丛发笋成竹2株以上，造林成活率95％以上。     

南县丛生竹引种育苗试验

湖南南县丛生竹种质资源缺乏,为了大规模发展南县的竹产业,提高南县人民的经济收入和维护南县的生态环境,采取斜埋秆育苗和直立埋秆育苗这两种育苗方法,对从湖南的龙山县和四川、江西等省地引进的丛生竹种进行了田间育苗栽植的对比试验。结果表明:斜埋秆育苗是一种行之有效而值得推广的育苗方法;在壤土、砂土、粘土这三种土壤质地类型中,壤土较适合丛生竹的生长;慈竹和青皮竹这2个丛生竹种比较适合在湖南南县栽植。     

几种造纸用丛生竹秆育苗试验

在福建省邵武市对橼竹、孝顺竹、坭竹等几种造纸用丛生竹进行秆节育苗试验表明，用平埋方法育苗显著优于斜埋直插，竹蔸平埋效果便佳；不同秆有苗成活率存在明显差异；不同年龄的秆节育苗成活率在不同竹种同间表现没；不同育苗时间（３月或５月）的成活率差异不显著。竹秆不同粗细、不同部位、单节段或双节段育苗对比试验，结果以细秆、上部节段、双节段育苗居活率较粗秆，下部节段、单节段的为高。橼竹杆节径用不同激素处理后，处理     

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.