油杉属植物研究动态

从系统分类学、植物地理学、繁殖生物学及保护生物学4方面对油杉属植物研究动态进行综述,结果表明,油杉属植物集中分布在中国南方地区,具有小种群的特点;通过对其细胞学、同工酶及植物地理学研究,对该属植物的分类及系统发育具有重要意义。油杉属发达的种翅可以使种子进行远距离传播,有利于种群的扩展,雄球花花粉成熟期较集中、寿命短,导致其结实率低;种子萌发条件的特殊要求,影响其自然更新。并提出了通过人工授粉、促进种子萌发、扦插和嫁接等人工辅助繁殖实现对我国油杉属植物资源的保护与利用,从而为该属植物的进一步研究奠定了理论基础。     

我国胡桃属(Juglans L. )种质资源与核桃(Juglans regia L. )育种

我国是胡桃属的分布中心,原产5种,已引进5种。本文提出将我国核桃的栽培实生群划分为新疆、华北山地、秦巴山地、西藏高地四个地理生态型;并对它们的分布区域及主要生态特征以及各个地理生态型内的重要实生类群作了简要论述。     

浅谈野生核桃楸的保护开发和利用

核桃揪是属于胡桃科胡桃属的落叶高大乔木,为第二纪孑遗植物,被<中国植物红皮书>列为三级保护植物.在中国主要分布于小兴安岭、完达山脉、长白山区及辽宁东部.大兴安岭林区东南部及河北、河南、山西、甘肃等地也有少量分布.由于过量砍伐,核桃揪现残存大树已很少.全国仅长白山建立了自然保护区,其它产区目前还没有采取保护措施,甚至系统...     

喀什地区核桃提质增效助力脱贫攻坚

正核桃又名胡桃、羌桃,为胡桃科胡桃属植物,与扁桃、腰果、榛子并称为世界"四大坚果"。核桃在新疆栽培历史已有1 500多年,是喀什地区主要经济树种之一。随着"国家木本油料产业发展战略"的实施,喀什地区核桃产业迅猛发展。截至2017年底,喀什地区核桃种植面积已达10.49万公顷(157.42万亩),其     

封面植物——深纹核桃

正深纹核桃(Juglans sigillata Dode)是胡桃科(Juglandceae)胡桃属(Juglans)植物,又名铁核桃、泡核桃、茶核桃、漾濞核桃。拉丁名中sigillata为种壳刻纹深密的意思,由法国分类学家Louis-Albert Dode于1906年进行命名,郑万钧院士在20世纪60年代对该命名进行确认,2021年在沈国坊院士主编的《中国主要树种造林技术》 (第二版)中也定名为深纹核桃。     

核桃楸的利用和苗木培育

核桃楸(Juglans mandshuricaMaxim)为胡桃科胡桃属植物,是东北地区珍贵的用材树种“三大硬阔”水曲柳、胡桃楸、黄波罗之一。其材质坚硬、致密,纹理通直、耐腐、弹性好、加工容易、刨面光滑、油漆性能好,广泛应用于建筑、船舰、车辆装修、军工、家俱等方面。国内自然分布于黑龙     

核桃楸栽培管理技术

核桃楸,属胡桃科,胡桃属,又名胡桃楸、楸子或山核桃。原产东北小兴安岭和长白山海拔500~1000m之间,多与红松、白桦、山杨、黄波罗、糠椴、水曲柳、槭类等组成混交林,河北、内蒙、辽宁等地散生。核桃楸是国家3级保护植物。     

核桃楸实生苗培育技术

核桃楸为胡桃科胡桃属落叶乔木,为我国Ⅲ级保护野生植物,也是我国东北地区珍贵的阔叶用材树种之一。介绍了核桃楸生物学特性、分布区域以及苗木培育技术。     

核桃楸的开发与利用

核桃楸又名山核桃、东北核桃、楸树、胡核桃,为胡桃科、胡桃属植物。核桃楸结实时间长,在自然状态下,树木成熟龄为150年,寿命可达250年,30年     

核桃良种选育工作的回顾与展望

核桃在我国已有二千多年的栽培历史,目前在华北、西北、西南地区和华东、中南、东北的部分地区均有大量分布,而且还生长着一定数量的原始群落。 核桃是核桃科核桃属植物,该属在世界上有20多种,我国目前有8种,而大量栽培的只有两种,即核桃(Juglans regia) 和铁核桃(Juglans Sigillata)。核桃主要在北方,     

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.     

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。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.