武夷山自然保护区生态旅游与社区经济发展模式探讨

促进协助保护区生态旅游和社区经济的共同发展是保护区的任务之一。武夷山自然保护区可以通过发展生态旅游、开发生态旅游关联产业,发展红茶种植加工业等多种途径,促进保护区社区经济的多元化发展。     

竹林生态旅游社区发展模式初探

近年来,随着竹林生态旅游的迅速发展,社区参与竹林生态旅游已成为人们关注的焦点之一。竹林生态旅游与社区发展存在良性互动关系,竹林生态旅游有力的促进当地社区的繁荣发展;当地居民生活质量的提升亦推动竹林生态旅游的环境保护和可持续发展。该文以竹林生态旅游社区文化悠久、竹林环境脆弱、景观特征独特、产业优势明显等特质为依据,提出以人为本、协调推进,长远规划、持续发展,主亚文化、协调一致,保持特色、突出形象,社区互动、合作互助等原则,针对竹林生态旅游不同社区的发展历程、产业结构、区域优势等特点,提出了社区发展的生态型、文化型、服务型、体验型等四种模式。     

生态旅游促进社区发展及存在问题分析——以茂兰自然保护区为例

阐述贵州茂兰自然保护区开展生态旅游的自然条件及生态旅游促进社区发展的重要意义,探讨保护区开展生态旅游的优劣势,分析社区参与生态旅游发展存在的问题,提出更好发展保护区生态旅游的一些建议。     

我国社区参与生态旅游研究进展——基于CiteSpace的知识图谱分析

发展生态旅游是契合当前旅游业高质量发展趋势以及践行“绿水青山就是金山银山”的有效途径,而社区参与作为生态旅游可持续发展的重要评判标准,持续引发研究者的关注。运用CiteSpace软件对生态旅游社区参与的相关文献进行了回顾,整理出该研究方向的历程与特征、研究趋势及研究热点,特别对社区参与生态旅游相关理论、社区参与模式、社区居民参与存在问题及对策等维度进行了梳理和评述,继而对未来可研究方向进行了讨论,以期为社区参与生态旅游的研究发展提供参考与借鉴。     

大熊猫国家公园陕西秦岭区生态旅游发展策略

为了促进陕西秦岭地区生态保护和资源利用的协调发展,通过对国家公园和生态旅游的关系进行梳理,可知生态旅游是国家公园游憩发展的最佳形式。调查发现,大熊猫国家公园陕西秦岭区的旅游业存在旅游开发影响生态资源质量、忽略社区有序参与、没有进行规范化管理等问题,在发展生态旅游的必要性探讨基础之上,对大熊猫国家公园陕西秦岭区生态旅游提出划定游憩科普区发展生态旅游、重视原有基础设施的使用、加强环境教育规划、引导社区参与、重视游客管理等发展策略。     

北京松山自然保护区生态旅游管理与当地社区参与

在自然保护区开展生态旅游能够为保护区筹集大量资金，维持保护区基础建设和管理工作的正常进行，促进自然保护事业的持续发展；为当地居民提供大量的就业机会，带动相关产业的发展；可改善保护区与当地居民的关系，使其成为自然保护事业的拥护者、支持者和参与者。文章分析了北京松山自然保护区的生态旅游管理与当地社区参与的现状及存在问题，提出了自然保护区生态旅游与当地社区关系的管理模式。     

生物圈保护区生态旅游开发模式研究

论述了世界生物圈保护区的产生和发展，分析了我国生物圈保护区发展生态旅游的现状与问题，提出了生态旅游的开发标准。根据宝天曼生物圈保护区旅游开发现状，提出了生物圈保护区在功能分区、开发程序、设施建设、机构设置、社区参与和可持续管理等方面的生态旅游开发模式，并把公众教育设施和环保设施的建设作为生物圈保护区生态旅游开发的重要特征。     

高黎贡山怒江段生态旅游发展基础探究

怒江州当前正处于经济发展和产业结构调整的关键时期,生态旅游被广泛认为是实现生态保护和旅游协同发展的重要途径。怒江州拥有丰富独特的文化、自然资源和地理优势,发展生态旅游将是实现当地经济结构调整和人民生活水平提高的重要举措,未来几年生态旅游将会成为该区域重点发展的生态产业。因此,摸清高黎贡山怒江片区开展生态旅游的基础条件,能够为今后高黎贡山国家公园发展规划和社区发展提供重要参考。2022年8月,调查了政府相关从业者和社区居民2个生态旅游的主要参与和核心利益相关人群对生态旅游的认知情况及对开展生态旅游的态度,怒江州12个州、县两级相关职能管理部门的185位相关部门工作人员参与了问卷调查,对怒江州泸水市、福贡县及贡山县的13个乡镇226户社区居民进行了入户访查。结果显示：85.87%(158/185)的相关管理机构从业人员表示了解生态旅游,50.63%(80/158)的职工能够完全理解生态旅游的概念和意义,且87.6%(162/185)的工作人员支持在怒江开展生态旅游活动。能够正确认识生态旅游概念和意义的社区居民相对较少(占比29.65%,66/226),但对当地开展生态旅游活动大都表示赞同(...     

基于社区共管的向海湿地生态旅游

湿地生态旅游是实现湿地自然生境与生物多样性保护、发展地方经济的有效手段。针对当前开展向海湿地生态旅游的优势与不足,借鉴国外先进经验,实行生态旅游社区共管不失为发展向海湿地生态旅游的优先选择策略。     

牯牛降国家级自然保护区的综合保护与发展

牯牛降自然保护区是同一纬度上最具保护价值的生物基因库，并具有良好的生态旅游开发前景。在保护森林生态环境和生物多样性的基础上，实行综合保护与发展，积极开发保护区生态旅游项目，促进保护区周边社区经济发展，使保护区建设实现持续稳定的可持续发展战略。     

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.     

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.     

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.     

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。     

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.     

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.