我国竹业发展现状与对策

文章总结了我国竹业发展５０年来的成就,论述了２１世纪社会可持续发展对竹业的需求,从确立以保护生态环境为基础、经济效益与生态效益并重的竹业发展方针;实施分类经营与定向培育,大力发展优质高效竹林资源;解放思想,抓住机遇,积极拓展竹子的利用方式和领域;坚持产业化方向,发展效益竹业,积极参与世界市场竞争;加快科技兴竹步伐,促进竹业高效可持续发展;普及竹业科技知识,提高生产者科技素质;建立竹业信息网络,进一     

关于河南竹业发展的思考

竹业被誉为 2 1世纪我国林业发展的朝阳产业。面对这一难得的发展机遇 ,竹业发展水平相对较低的河南省应怎样调整对策呢 ?本文作者展望竹业发展前景 ,分析了我省当前竹业发展中存在的问题 ,并结合省情、竹情 ,提出了我省发展竹产业的途径 ,可为制定我省竹业发展规划提供参考     

中国竹业产业化发展模式研究*

我国竹业经过近50年的改革和发展．逐步成为世界上最大的竹子生产、消费和出口国。竹业是一个集生态、经济、社会效益于一体的朝阳产业。文中结合竹产业的特点．总结了目前我国竹业产业化过程中出现的主要发展模式及其特点。提出了未来我国竹产业发展可采取的模式．并就模式运行所涉及的资源基地建设、市场体系和龙头企业选择等进行了探讨。     

中国竹子之乡引领中国竹业发展——国家林业局副局长祝列克专访

1996年原林业部命名了十大“中国竹子之乡”,对推动中国竹业发展发挥了重要作用。随着我国竹业的迅猛发展,一批竹业重点县脱颖而出。为进一步发挥“竹乡”的示范带动作用,2006年国家林业局命名了包括原有十个竹子之乡在内的30个“中国竹子之乡”。日前,本刊记者专门采访了国家林业局副局长祝列克。记者：中国竹子之乡是引领中国竹业发展的火车头,请您谈谈中国竹子之乡的由来。祝列克：我国是世界竹类资源最为丰富的国家,有着悠久的栽培利用历史。党的十一届三中全会以后,特别是上世纪90     

南平竹业开发亮点频闪——开展竹业开发擂台赛三年回眸

福建省南平市人民下发政府关于开展竹业开发擂台赛活动的通知([2002]综13号)后,连续开展了3年竹业开发擂台赛活动,不仅是竹业经济飞速发展的3年,而且是竹业经济呈现出前所未有的强劲发展态势,竹业开发频闪着10个新亮点。     

关于集体林权制度改革与竹业发展的思考

从社会、经济、生态和竹资源开发利用等方面思考了集体林权制度改革与竹业发展的关系,认为集体林权制度改革给竹业发展带来的活力,科学技术进步给竹业发展创造的潜力,二者相互作用,共同推进,这将使我国竹业进入良性的快速发展期,成为极具发展潜力和竞争力的朝阳产业,给广大山区的社会主义新农村建设作出贡献。     

加快竹业发展之我见

竹林是我国森林资源的重要组成部分,也是生态、经济和社会效益结合最好的林种。搞好竹业建设,对增加森林资源,加快国土绿化步伐,壮大林业经济实力,增强林业活力,增加农民收入,促进产区经济社会发展,实现全面建设小康社会目标等,都具有十分重要的意义。近年来,全国竹业工作有了快速发展。竹林面积达6300万亩,年产值370多亿元,出口创汇约6亿美元,我国已成为世界竹林面积最大、产量最高、效益最好的国家之一。福建省是我国竹业面积最大的省。全省竹林总面积达1230万亩,占全国竹林总面积的19.5%。2003年,全省竹业总产值达86亿元,比2002年增加13亿元。湖南省桃江县是闻名遐迩的“全国十大竹子之乡”。2003年全县竹业总产值达11亿元,占全县国民生产总值的25%,农民收入1/3来自竹业。福建省政和县铁山乡高林村依靠发展竹业实现人均增收2400元,占全村人均收入的2/3以上。贵州省赤水市农民收入中的40%来自竹子。这样的事例举不胜举。竹业已成为我国林业建设中最具活力和潜力的发展领域,处处呈现出一派生机和活力。,,,,,但是,应当清醒地看到,我国竹业工作还存在一些问题,突出表现在:一是对竹业工作不够重视,没有把这项工作摆上重...     

国际竹藤组织竹业考察团参观中国竹产业

为了考察中国竹业改革开放以来所取得的巨大成就,提高世界上其它国家发展竹业的积极性,2008年4月,国际竹藤组织组织了在浙江和四川的竹业考察。     

四川马边彝族自治县竹业发展现状及对策

在对马边县竹资源和竹产业现状实地考察的基础上,根据当地社会经济的发展需要,顺应我国竹业发展趋势,以竹业富民为目标,探讨和分析了马边竹业发展的优势及所存在的问题,提出了竹资源保护与合理开发利用、建设地方特色竹产业等建议,旨在指导经济落后的西部地区竹业的健康可持续发展。     

加速推进我国竹产业发展

我国是世界上最主要的产竹国,竹类种质资源、竹林面积、竹材蓄积和产量均居世界首位。党的十一届三中全会以来,国家实行的一系列改革开放政策促进了我国经济腾飞,也为竹业发展提供了难得的历史机遇,使中国竹业得到了空前发展,形成了一个     

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.     

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.     

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.     

Boron in forest trees and forest ecosystems

This review critically examines the role of boron (B) in forests in view of recent findings on B nutrition and the continuing occurrence of B deficiency. Many perceptions about the role of B in plants and its uptake and mobility have been altered since the last review on B in forest trees in 1990. Now there is evidence for a fundamental role of B in the formation of the pectic structure in primary cell walls in plants, and further roles in membrane function are being explored. In plants, channel-mediated B uptake, active B uptake and B uptake by mycorrhizas have been shown, B transporters have been identified, and B retranslocation has been shown. We explore these findings and their consequences on forest trees and on ecosystems that they dominate. Particular emphasis is placed on B retranslocation and B in mycorrhizal symbiosis, given their importance in trees.     

Survival and Growth of Picea abies Regeneration after Shelterwood Removal with Single- and Double-grip Harvester Systems

Three stands in Sweden were followed for 7 yrs to study the survival and growth of Norway spruce [Picea abies (L.) Karst.] regeneration after shelterwood removal with single- and double-grip harvester systems. The height of all seedlings within circular plots was recorded before and after final cutting. The tallest seedling and one randomly selected seedling on each circular plot were permanently marked and their annual height growth was measured each year during the period 1993-1999. No significant differences between single- and double-grip harvester systems were found with respect to their effects on regeneration density, survival or annual height growth. The annual height growth of the individual seedlings after shelterwood removal was significantly correlated with seedling height before shelterwood removal. Significant differences were found in annual height growth between seedlings with high and low vitality. Logging damage did not affect the annual height growth. Several practical conclusions were drawn. First, the choice of harvester system does not affect seedling height growth or survival after shelterwood removal. Secondly, the removal of a 200 m³ shelterwood with 200 stems ha^-1 does not seem to constitute a serious problem for seedling survival and growth. Finally, estimated vitality and seedling height both seem to be fairly good predictors of postrelease survival and growth.     

Development of Pinus sylvestris Main Stems Following Three Different Precommercial Thinning Methods in a Mixed Stand

Reducing competition by point cleaning may be an attractive alternative to conventional precommercial thinning in forestry. In this study, survival and development of main stems of Scots pine (Pinus sylvestris L.) following point cleaning were examined in a mixed stand of mainly Scots pine and birch (Betula pendula Roth and Betula pubescens Ehrh.) in northern Sweden. Treatments studied were: no precommercial thinning, conventional precommercial thinning, point cleaning of all secondary stems, and point cleaning of only the secondary stems that were higher than the main stem, within a radius of 0.8 m from the main stem, respectively. A randomised complete block design with three replicates was used. Measurements taken 13 growing seasons after these treatments showed that conventional precommercial thinning was the best treatment for retaining Scots pines as main stems. However, conventional precommercial thinning resulted in the poorest timber quality of the remaining Scots pines in terms of stem taper, thickest branch diameter and relative live crown height. In conclusion, point cleaning has to be followed by a complementary cleaning operation if the objective is to retain Scots pines as main stems in such mixed stands.