加强林业生态经济研究,实施生态建设富民工程

从理论与实践的角度分析湖南林业发展的基本特点，指出了林业生态经济在湖南林业建设中的重大意义，提出了林业生态经济研究的主要内容及实施生态建设富民工程的建议。     

蓬勃发展的湖南林业

1 湖南林业发展战略研究与规划湖南地处 我国中南部，气候温和，雨量充沛，土地肥沃，是南方重点林区。20世纪90年代，已成为全国第三个消灭宜林荒山和实现基本绿化的省份。2005年，湖南省委、省政府做出了建设“和谐湖南”的战略决策，把以林业建设为主体的“生态湖南”与“诚信湖南”、“平安湖南”、“小康湖南”一起作为“和谐湖南”定位的四大内容之一。     

林业生态保护和建设在生态环保型经济框架中的作用和发展思路

实施可持续发展战略,发展生态环保型效益经济是吉林省人民政府的战略构想。本文从森林的生态、社会和经济三大效益入手,较全面地研究论证了林业生态保护和建设在“生态环保型效益经济”框架中的作用,并对今后如何进行林业的生态保护和建设提出了发展目标、建设重点和战略措施。     

建设和谐林业助推绿色湖南建设的策略

从“天人合一”哲学思想出发,阐述了和谐林业基本概念及特征,提出了构建和谐林业的发展思路.在深入分析发展和谐林业重要意义基础上,结合湖南林业建设实际,提出了普及森林文化及生态文明理念;转变林业发展方式;深化林业改革;加快科技创新;健全林业法制等战略措施,助推绿色湖南建设.     

建设和谐湖南新林业 打造绿色幸福新家园——访湖南省林业科技推广总站站长刘跃进

2008年1月9日,湖南省省长周强主持第10届省人民政府第117次常务会议,听取省林业厅厅长葛汉栋关于《湖南现代林业发展战略研究与规划》的汇报。一致认为,这个战略规划创造性地提出了“建设和谐湖南新林业，打造绿色幸福新家园”的发展理念，描划出了“一湖三群五片多点”的林业建设宏伟蓝图，对湖南现代林业建设具有重要的指导作用，务必要认真实施，认真落实。政府常务会议的精神激起了我们采访参与这次战略研究的湖南省林业科技推广总站站长刘跃进的兴趣。     

山区林业生态体系建设的探讨

山区的林业生态体系建设是关系到山区的发展,关系到全省社会、经济和环境状况及福建林业可持续发展战略的重要环节。正视山区林业生态体系建设的现状,采取积极有效的措施,建设山区生态林业体系是山区林业的当务之急。文章分析了山区林业生态体系建设的现状,同时对发展山区林业生态体系建设作了探讨。     

葛汉栋厅长考察绥宁林业

4月16日下午，省林业厅葛汉栋厅长一行在绥宁考察林业工作。在听取绥宁县委、县政府的有关汇报后，葛厅长指出绥宁林业是全省林业的骄傲，不愧为三湘林业第一县，绥宁要继续保持这个荣誉，长期成为湖南林业的领头雁。绥宁林业发展的当务之急是实施三大战略，构建三大体系：即实施“生态、经济、社会”三大效益一齐要，“一、二、三次产业”一齐上，“林业、林农、林区”三林问题一齐抓的“三三”战略；构建完善的林业生态体系、发达的林业产业体系和繁荣的生态文化体系。葛厅长还要求绥宁应努力搞好集体林权制度改革试点，改革育林基金使用管理，落实林改后林产工业的后续问题及财政转移支付问题，要求绥宁在处理县际山林纠纷时姿态要高一点，相互沟通解决。     

对景宁英川镇林业发展的思考

指出了为贯彻和落实科学发展观，坚持以实施“创绿色英川、建生态大镇”发展战略，加强林业建设，提高林业的质量和效益，加速推进传统林业向现代林业的转变，为了达到人与自然和谐共处的目的，英川镇对全镇林业建设实行求真务实，开拓创新，努力开创发展现代林业、建设生态文明、促进科学发展的新局面，对英川镇林业发展进行了思考，为从事林业工作者提供参考。     

大会选举

学会的宗旨：团结、组织广大林业科技工作者，贯彻执行党的基本路线和“百花齐放、百家争鸣”的方针，坚持依法治疗和民主办会，倡导求真务实，实事求是和尊重知识、尊重人才的风尚，大力开展科技攻关、学术研讨、技术交流和科学技术普及、推广活动，积极推动林业科技进步和技术创新，促进“依靠大科技、发展大林业、推进大开放、实现大跨越”四大生态林业发展战略和“中部农防林改造、东部天然林经营、西部生态草建设”三大区域林业发展战略的实施，为“发展生态林业、建设秀美吉林”，“推进历史性转变、实现跨越式发展”做出积极贡献。     

加快湖南林业经济发展的建议

加快湖南林业经济的发展，要以科技为手段，加快发展林业的“亮点”经济；采取措施，促进重点林区的恢复与发展；围绕湖南林业生产中的重点、热点、难点问题，加大科技兴林工作力度；以人为本，加强队伍建设；实施分类经营，调整森林经营周期结构；创建林业科技示范园。     

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.     

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。     

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.