红松坚果林培育现状与展望

综述了红松结实、红松坚果林培育、红松坚果型优树选育以及红松坚果林无性系选育与繁殖等方面的研究进展,并对今后红松坚果研究提出了展望。     

林分结构对红松分杈的影响

文章分析了5项林分因子对红松分杈的影响及其成因。其中,林分类型、红松径级、红松成数对红松分析影响达极显著或显著水平,林分密度、林分年龄对红松分杈也有一定影响。但分析认为林分类型、林分密度和红松成数是影响红松分杈的直接因素;林分年龄、红松径级对红松分杈无直接因果关系,这是通过他形成的林分形态、结构和生理特性而影响红松分杈的。降低红松分杈率必须严格实行栽针保阔,保留适宜的林分高密度和红阔比例,降低红松分杈率,同时,可以提高林分质量,构建健康稳定的阔叶红松林。     

人工阔叶红松混交林生物量特征

以辽东山区人工阔叶红松混交林为研究对象,以红松(Pinus koraiensis)纯林为对照,调查分析了红松-白桦(Betula platyphylla Suk.)、红松-色赤杨(Alnus tinctoria)、红松-水曲柳(Fraxinus mandshurica)、红松-刺楸(Kalopanax septemlobus)、红松-紫椴(Tilia amurensis)人工阔叶混交林的乔木层、灌木层、草本层及总生物量。结果表明:人工阔叶红松混交林总生物量的大小与混交林中与红松伴生的阔叶树种生长速度有关,如果伴生树种生长速度快于同龄红松生长,林地总生物量明显大于红松纯林;反之小于红松纯林。并且红松纯林内灌木层、草本层生物量低于各类型的阔叶红松混交林。     

桓仁县红松种子产业发展现状、问题及建议

红松种子是营养丰富、经济价值高的绿色食品。发展红松种子产业对于促进林农增收、推动县域经济发展具有重要作用。该文从桓仁县红松林面积、红松种子产业发展现状及存在问题等方面介绍了桓仁县红松种子产业的基本情况,同时,提出了桓仁县红松种子产业发展建议,对桓仁县红松种子产业发展具有一定的指导意义。     

不同混交类型对红松生长和土壤特性的影响

2010年在草河口地区进行了不同混交类型造林试验,通过对9年生试验林生长和土壤理化性质的调查研究,结果表明:红柞(Xylosma racemosum)、红松(Pinus koraiensis)、水曲柳(Fraxinus mandshurica Rupr.)混交林中的红松树高、胸径生长都明显高于红松纯林,红松、落叶松[Larix gmelinii(Rupr.) Kuzen]混交林红松生长于红松纯林相比无显著差异。红柞、红松、水曲柳混交林土壤与红松纯林相比,土壤蓄水能力增强,养分含量增加,红松、落叶松混交林与红松纯林相比土壤理化性质无显著差异。红柞、红松、水曲柳混交林值得推广。     

红松的生物学研究进展

【目的】本文对红松生物学特性方向的相关研究内容进行了综述,以期为红松资源的合理开发利用以及更深入的研究提供理论依据。【方法】整理红松近年来与生物学特性相关的研究报道进行总结和分析。【结果】本文主要涉及了红松的开花结实规律、光合特性、繁殖特性、逆境生理、分子标记、遗传多样性、基因组研究以及红松籽油与多酚等研究方向。通过高通量测序和生物信息学研究,获得大量的红松转录组基因,为红松次生代谢产物合成相关基因的研究提供了参考。同时分子标记的开发也揭示了红松的遗传多样性,为红松的品种选育奠定了基础。【结论】红松的光合特性以及逆境胁迫的研究阐述了矿质元素与环境因素对红松苗木生长的影响,红松的嫁接技术以及组织培养技术也已经比较成熟,可以为后期优质红松苗木生产提供技术支撑。但对于其他领域的研究则相对较少,特别是在与红松的遗传育种工作紧密相关的种质资源研究和基因组研究方面的研究较为缺乏。     

红松与色赤杨混交林的生长量及土壤理化性质研究

该文通过对红松与色赤杨混交林与红松纯林生长量及土壤理化性质对比研究表明：红松、色赤杨混交林明显促进红松和色赤杨的生长,提高了林分生产力。20年生混交林中的红松平均胸径和平均树高比红松纯林分别提高4．9％和21．7％。混交林蓄积量比红松纯林提高59．6％;红松、色赤杨混交林林地土壤的理化性质得到明显改善,土壤容重减小,土壤孔隙度增大,有机质及养分含量增加,从而提高了土壤的供肥能力。     

东北红松阔叶混交林的分布规律分析

红松阔叶混交林在东北东部山区分布极为广泛,是该地区水平地带性和垂直地带性森林;将东北红松阔叶混交林分为3部分:典型阔叶红松混交林,河岸、河谷阶地阔叶红松混交林和山背、陡坡阔叶红松混交林;介绍了红松阔叶混交林组成、分布规律及其地势的特点。     

吉林省蛟河市红松母树林改建技术研究

红松是我国重要的珍贵树种之一,主要分布在东北地区。红松果仁在国内外市场倍受欢迎,具有很高的开发价值。由于红松果仁需求量的不断增加,红松种子遭到掠夺性采集,红松资源不断受到蚕食,红松林越来越少。吉林省中东部人工红松林分多数正值中、壮龄林,选择优良红松林分改建红松母树林,是扩大发展红松资源、改良提高红松遗传品质、加快林区经济发展一项重要措施。     

浅谈阔叶林冠下红松造林技术

红松是我国珍贵树种之一,具有很高的经济价值.文章阐述了红松的形态特性,从阔叶林地的选择、整地、适时造林、红松栽植、保水剂的使用、苗木栽植等6个方面介绍了阔叶林冠下红松的造林技术以及红松幼苗抚育后的苗期管理工作.     

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.     

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.     

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.