基于多层次灰色方法对大兴安岭地区生态旅游开发潜力研究

大兴安岭地区蕴含的生态旅游资源极其丰富,对该地区进行开发潜力评价,可以为其生态旅游资源的开发提供科学指导依据。本研究从旅游资源条件、旅游资源开发条件、旅游资源开发效益和旅游资源价值四个方面构建了一个包含20个评价指标的生态旅游资源开发潜力评价体系,通过对该地区生态旅游资源开发潜力的评价,从而确定该地区生态旅游资源优先开发的先后次序。依据综合计算值,将大兴安岭地区的7个市县区生态旅游资源开发潜力大小分为了三个等级,其中漠河市和塔河县开发潜力最大为一级生态旅游资源开发潜力区,呼中区、呼玛县、加格达奇区开发潜力适中为二级生态旅游资源开发潜力区,松岭区和新林区的开发潜力最小为三级生态旅游资源开发潜力区。评价结果大体与实际情况相符,说明用多层次灰色方法对该地区进行的潜力开发评价可以为大兴安岭地区生态旅游资源开发和发展提供助力。     

兴凯湖自然保护区旅游资源评价

阐述由“一孤五点”构成的兴凯湖国家级自然保护区旅游资源概况及开发现状。运用田野勘测、资料统计分析和调查问卷法进行游客对景点认可度、提供服务满意度和服务存在问题以及对景区改善提高项目的调查。资源评价结果，该区旅游资源属二级旅游资源，旅游开发尚处于起步阶段，具有较大开发潜力，适合开展生态旅游。提出了开展生态旅游要以保护为前提，合理布局，科学规划的建议。     

横头山国家森林公园旅游资源评价

旅游资源的评价是旅游开发的基础。在大量调查数据和资料的基础上,结合层次分析法和模糊计分法对横头山国家森林公园旅游资源进行评价与分析,构造矩阵确定森林公园各评价因子的权重系数;采用游客调查和专家判断相结合的方法,对各因子进行模糊计分,从而建立横头山国家森林公园旅游资源综合评价的指标体系和模糊评价的数学模型。评价结果为：横头山国家森林公园旅游资源评价的最终分值为7.1592,开发潜力为Ⅱ级。     

甘肃大河坝国家森林公园旅游资源评价

采用打分评价方法对甘肃大河坝国家森林公园进行评价，结果为该公园有特品级旅游资源3个，优良级旅游资源89个，普通级旅游资源41个；按风景资源的类型分类定级，风景资源质量等级为一级。     

生态旅游资源评价模型建构与实证研究——以江苏36个生态旅游区为例

传统的旅游资源评价模型过度强调旅游资源本身的价值,已无法满足评价对与生态环境有较强依赖性的生态旅游资源的需要。基于已有文献研究基础之上,提出了适应当前生态旅游发展需要的生态旅游评价模型,指标突出了生态旅游的本质,包括生态旅游资源条件、区域条件、开发潜力和生态环境健康4个方面的内容。以江苏省36个主要的生态旅游区为例,运用熵值法以及层次分析法中的和积法相结合的赋权方法进行实证分析,并基于评价结果将这36个生态旅游区进行了分类研究,证实了评价模型的可操作性及在生态旅游发展背景下的指导价值。     

基于AHP的乡村旅游资源评价——以福建长泰山重村为例

以福建长泰山重村为研究对象,从乡村旅游资源价值、环境氛围、开发条件3个方面选取乡村聚落、乡村建筑、乡村历史、乡村民俗、乡村山水风光、乡村田园风光、科学考察价值、安全性、卫生状况、植被覆盖率、旅游环境容量、区域经济发展水平、可进入性、旅游服务、基础设施及客源市场等作为主要评价指标,建立多层层次结构模型,运用层次分析法对其进行乡村旅游资源综合评价,得出山重村乡村旅游资源综合评价得分为71.01,结果表明:山重村乡村旅游资源总体良好,具有很大的乡村旅游开发潜力。最后根据评价结果为其乡村旅游发展提出了科学的建议。     

南宫山国家森林公园旅游资源价值评价

旅游资源评价是科学地开发和利用旅游资源的前提,文章运用定量评价中的对比分析法对南宫山国家森林公园旅游资源进行了评价,结果表明南宫山国家森林公园自然旅游资源丰富,特色突出,开发潜力大。使人们对其有一个更准确、更客观的认识,为进一步科学、合理的开发南宫山国家森林公园提供参考。     

基于层次分析法的派阳山森林公园森林风景资源综合评价

基于森林公园宏观环境,运用层次分析法对派阳山森林公园风景资源进行综合评价。通过构建以森林风景资源质量评价、区域环境质量评价和森林公园旅游开发利用条件评价为项目层的森林公园风景资源综合评价指标体系,建立综合评价计算模型,划分等级标准,分析派阳山森林公园开发生态康养旅游的资源潜力。评价结果显示,派阳山森林公园风景资源综合评价体系中,项目层评价得分与权重值得分高低顺序保持一致,风景资源综合评价总分值为78.28分,处于康养旅游开发的4级水平,具有较高的风景资源价值。同时也存在着资源未完全开发利用、配套设施不齐全等劣势指标,可通过康养科普、山地运动等项目建设,来完善内部设施,实现兼顾生态、经济、社会效益的风景资源综合开发利用。     

牡丹峰国家森林公园旅游资源评价与开发对策

在对牡丹峰森林公园的旅游资源细致调研的基础上，首先采用定性的方法，从直观上描述、评价了牡丹峰森林公园的旅游资源，然后运用层次分析法与数学模糊打分法对其进行了旅游资源的定量评价，据此对牡丹峰国家森林公园的开发建设提出了相应的对策。     

兴凯湖自然保护区旅游资源评价

阐述由"一弧五点"构成的兴凯湖国家级自然保护区旅游资源概况及开发现状。运用田野勘测、资料统计分析和调查问卷法进行游客对景点认可度、提供服务满意度和服务存在问题以及对景区改善提高项目的调查。资源评价结果,该区旅游资源属二级旅游资源,旅游开发尚处于起步阶段,具有较大开发潜力,适合开展生态旅游。提出了开展生态旅游要以保护为前提,合理布局,科学规划的建议。     

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.     

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.     

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.     

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.     

Tree planting for dryland salinity control in Australia

Dryland salinity is emerging as a major form of land and water degradation in southern Australia, particularly in Western Australia, South Australia and Victoria, and to a lesser extent in New South Wales, Tasmania and Queensland.Tree planting, in combination with other vegetation treatments, is regarded as a leading solution to dryland salinity. Research has now shown that planting trees can significantly lower groundwater tables, and thereby reverse the causal process of salinisation. Substantial progress has been made towards answering the basic questions of which species to grow, how to plant, where to plant, at what density and configuration to plant, and how much area to plant. The economic potential for commercial tree planting has given impetus to partial reforestation in higher rainfall (> 600 mm yr^–1) areas. Even so, serious constraints are apparent, relating primarily to cost, uncertainty and attitude. The future should bring increasing community input and control, technical refinement and gradual adoption, provided all aspects of the issue are well researched, relevant information is well communicated and programmes are well administered. Some specific requirements for future research are identified in this review.     

Effect of Cuttings on the Scenic Beauty of a Tree Stand

The opinions of 207 respondents on the visual effects of seven different cutting types were asked using a nine-point verbal scale ranging from ''worsens very much'' to ''improves very much''. Other estimates were obtained by letting the same respondents evaluate photographs of stands which had been treated with different cuttings. The direct questions gave results quite similar to the evaluations of photographs for all but young respondents, indicating that most respondents were able to imagine the effect of the treatment correctly. The results based on the evaluation of photographs indicated that the effect of regenerative cuttings is negative while the impact of thinnings is positive. After a few years of cutting the stand is already regarded as clearly more pleasant than immediately after the cutting. Natural regeneration with seed trees seems to be a way to avoid the very negative immediate impact of clear-felling, especially in the case of Scots pine. Women, young, urban people and those who do not own forest or have work related to forests tended to experience thinnings less positively and saw regenerative cuttings as more harmful than the other test groups did.     

Pinus contorta growth in northern Sweden as affected by soil scarification

The aim of this study was to quantify the effects of different soil scarification methods on tree growth. Soil scarification influenced stem volume and stem biomass yield of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) in a 17-year-old field trial in boreal Sweden. Soil scarification (disc trenching, mounding and ploughing) resulted in an average stem volume yield of 3.1 and 34.2 m³ ha^–1 on the poor and intermediate sites, respectively, while corresponding values for no soil scarification were 0.9 and 16.7 m³ ha^–1. In comparison to no scarification, ploughing increased volume yields by 500% on the poor site and by 200% on the intermediate sites. The ranking according to stem volume yield was ploughing > disc trenching = mounding no soil scarification. Averaged over the two sites, the mean annual increment of stem biomass was 219% and 145% higher (in d.w., 0.26 kg and 0.34 kg per sample tree) after ploughing compared with no soil scarification, for the average and dominant sample trees, respectively. Although not significant, the increased growth rate after soil scarification decreased the average stem basic wood density of the sample trees with 1.6% and 5.3%, at the poor and intermediate sites, respectively. In conclusion, soil scarification significantly increased the 17-year stem volume yield compared with no scarification. The results also indicate that the difference in stem biomass yield between ploughing and the other methods, especially no soil scarification, will increase even more in the near future.