三个观赏型杜仲无性系叶片色素含量比较

正杜仲(Eucommia ulmoides Oliv.)是我国特有的经济树种,也是分布范围最广的胶原植物[1],红叶杜仲是中国林科院经济林研究开发中心选育的具有一定观赏性的杜仲药用优良无性系,其叶片暗红色,与其他无性系差别明显。花色苷是花色素与糖以糖苷键结合而成的一类化合物,广泛存在于植物的花、果实、茎、叶和根器官的细胞液中,使其呈现由红、紫红到兰等不同颜色[2,3]。根据侯元凯[4]对彩叶树种叶片不同颜色的产生原因的描述,叶片颜色主要是由叶片中光合色素种类、含量以及花色苷含量引起。     

27个柳树无性系对镉的吸收分配特性

【目的】研究27个柳树无性系的根、插穗树皮、枝条和叶片对Cd~(2+)的吸收分配特性,获得地上部和地下部富集Cd浓度最大的无性系,为Cd污染地的植物修复提供理论参考,为进一步研究柳属植物对Cd~(2+)的解毒机制提供依据。【方法】以具有优良经济价值和观赏价值的27个柳树无性系为研究对象,在水培条件下,40 mg·L~(-1)Cd~(2+)胁迫6天,分别取根、枝条、叶片和插穗树皮样品,采用原子吸收分光光度计测定不同部位的Cd浓度,并计算地上部插穗树皮、枝条和叶片对Cd向地上部转运的贡献率。【结果】27个柳树无性系Cd~(2+)主要富集在根中,很少向地上部转移,根Cd浓度为1 106.08~4 261.46 mg·kg~(-1),无性系柳Q2根中Cd浓度仅为蒿柳的25.96%,地上部Cd浓度为38.29~207.87 mg·kg~(-1),柳D31地上部Cd浓度仅为柳SH31的18.42%;柳SH31叶片、枝条和树皮中Cd浓度均高于其他柳树无性系,分别为177.17、506.85和263.04 mg·kg~(-1);27个柳树无性系对Cd的转运系数均较小,最小的柳2465为0.016,最大的柳SH31也仅为0.199;叶片、枝条和树皮对Cd向地上部转运的贡献率不同,柳Q43和柳SH18的枝条对Cd转运的贡献率最大,分别为56.3%和57.2%,其他无性系树皮的贡献率最大,最大的柳23达到了88.5%,最小的柳Q43为28.6%,仅为柳23的32.3%。【结论】27个柳树无性系主要将吸收的Cd富集在根中,以较少向地上部转移;蒿柳根富集Cd浓度最大,主要将吸收的Cd固定在根中,以减少其对自身其他器官的伤害,同时降低土壤中有效Cd的浓度,减少其对其他植物的伤害;柳SH31地上部富集Cd浓度最大,可通过多次短轮伐并收集地上部达到减少土壤中Cd~(2+)的目的。     

园林绿化良种—金丝垂柳优良无性系

垂柳（Salixbabylonica）“碧玉妆成一树高，万条垂下绿丝绦”，是我国栽培历史悠久的重要园林绿化树种，但是它的枝条为绿褐色，特别是落叶后，因枝色灰暗，又给人一种“枯树、落叶、寒鸦”的凄凉之感而严重影响其观赏价值。垂柳雌株在种子成熟时，大量的柳絮造成环境污染，限制了它的发展。为了改良垂柳枝条颜色、枝条下垂度、小枝长度及花序的大小等观赏性状，江苏省林业科学研究院涂忠虞研究员在承担国家“七五”科技攻关课题“柳树良种选育及优良无性系区域化”（编号：７５—０７—０１—２２）的研究期间，选用垂柳为母本与枝条金黄…     

两种柳树无性系幼苗生长和光合特性研究

为进一步比较不同柳树无性系幼苗生长及光合特性的差异,选择优良柳树无性系,以垂爆109柳SalixבChuibao 109’和旱快柳Salix matsudana var.anshanensis为试材,采用Hoagland营养液水培方法,研究正常情况下垂爆109柳和旱快柳幼苗生长性状和光合特性。结果表明:培养45d后,与旱快柳相比垂爆109柳幼苗的叶片数、叶长、根长、根数、基径无显著差异;垂爆109柳的叶宽、叶间距、新枝长、枝条鲜质量和干质量,根鲜质量和干质量,都明显高于旱快柳(p<0.01)。垂爆109柳和旱快柳的净光合速率有明显的差异,净光合速率值在不同光照强度下均表现为垂爆109柳>旱快柳。垂爆109柳的光饱和点和光补偿点都低于旱快柳,表明旱快柳具有较强的光强利用能力,强光照射对旱快柳的抑制作用较低;而垂爆109柳利用弱光的能力较强。     

50种山茶科植物的综合评价

应用层次分析法,选择观赏特性、生态习性、利用价值作评价因素,对山茶科50个原生种进行了综合评价。结果表明:观赏特性为最重要评价因素,生态习性居次,最后是利用价值;观赏特性的指标层按权重值大小排列依次是形、花、叶、果、枝。50种山茶科植物分为3个等级,Ⅰ级有14种,形态特征明显,观赏价值高,被开发利用程度也最高;Ⅱ级有20种,观赏性还未受到关注,开发利用潜力很大;Ⅲ级16种,观赏性偏低,未见应用,但有些种科研价值很高。     

不同光强对6个欧美杨无性系苗期生长及光合特性的影响

[目的]研究6个欧美杨无性系生长及光合特性对不同光强的响应差异,为欧美杨苗期快速选育高光效优良品种提供一定的理论依据。[方法]在大田用遮阴网设置CK(100%自然光强)、L1(55%自然光强)和L2(20%自然光强),测定欧美杨的苗高增长量、叶片形态、光合速率、叶绿素荧光特性、叶绿素含量及矿质元素含量。[结果]除11-26-9外,无性系的苗高总生长量随着光强的降低呈下降趋势;随着光强的降低,不同无性系的叶片形态变化趋势不一致,3个光强下无性系间的单叶面积、叶形指数和比叶面积存在差异;无性系在L2处理下的净光合速率(Pn)最低,胞间CO2浓度(Ci)最高;3个处理下,11-26-8的气孔导度均最大;在L1与L2下,11-26-9的F1/F0值均最大;无性系的叶绿素b含量与叶绿素总含量呈现相同的变化趋势;11-26-4、11-26-8和11-36-26的钾、钙、镁元素含量随着光强的降低而增加。[结论]不同无性系对光强变化的适应策略不同,部分无性系的高生长和净光合速率随着光强的降低而减小,降低光强没有破坏无性系的PSⅡ结构。多数无性系的总叶绿素含量、矿质元素含量随着光强的降低而升高。11-36-26无性系的生长势及抗弱光能力较弱。     

黑木相思14个无性系叶片性状变异分析

在6年生黑木相思(Acacia melanoxylon)无性系试验林中,对14个无性系的叶长、叶宽、叶面积、叶柄长、叶厚、比叶面积及叶干物质量共7项叶片性状进行了测定和变异分析。结果表明:叶面积和叶柄长变异系数较大,叶干物质量的变异系数较小,且叶片性状的变异主要为无性系之间的变异;黑木相思无性系叶片性状之间存在相关性,叶长、叶柄长和叶宽与叶面积呈极显著正相关,而叶面积、比叶面积与干物质量呈极显著负相关,叶厚与比叶面积呈极显著负相关;主成分分析表明,除叶柄长外,其它6个叶片性状都是鉴定无性系的重要特征指标。聚类结果显示,14个无性系聚为4类,F1、SR38、SR41被单独聚类,其它11个无性系聚为1大类,说明大部分无性系叶片性状变异不显著。     

柳树光合特性遗传变异的初步研究

对10种柳树20个无性系的一年生扦插苗的苗高(H)、单叶面积(a),单株叶面积(A)、侧枝长(L)、侧枝干重(l)、苗干干重(h),净光合速率(t)和单株干物质生产速率(T)等性状进行了测定。应用方差分析、相关分析和通径分径的方法,研究其光合特性的遗传变异和相关。结果表明:柳树种间及无性系间光合特性的遗传变异是很显著的,单株叶面积对苗高直接影响最大,其P_(H.A)=11.3338,苗高与光合性状相关系数组分中,也都明显反映出单株叶面积强烈的正向作用。因此,增加单株叶面积是培育用材柳树的关键。     

幽叶蜂属一中国新记录种——柳褶幽叶蜂

报道在山东地区早春时节普遍分布且严重危害柳树致叶片背面呈褶叶危害状的中国新记录种-柳褶幽叶蜂Euura plicaphylicifolia(Kopelke, 2007)；记述其形态特征和生物学特性。提供了与其同期危害的柳蜷钝颜叶蜂Amauronematus saliciphagus Wu, 2009的主要鉴别特征。     

观赏桃在石家庄地区的园林观赏性综合评价

以河北省林业和草原科学研究院资源圃中的26个观赏桃品种为试材,运用AHP层次分析法对其观赏性、生长势、应用价值3个方面的12项评价指标构建评价体系,研究了观赏桃各个品种的观赏性综合评价体系,以期筛选适宜在河北及周边地区栽植应用综合观赏性高的品种。结果表明：观赏桃的观赏价值权重最大,为73.2%,生长势和抗性相对来说对其影响较小;12项影响观赏桃综合观赏性评价的指标总排序权重排在前3位的是花色（17.8681）、花瓣数量（17.8242）和花期（12.2098）,这3个指标对观赏桃的综合观赏价值影响最大。根据综合指数分值,红碧桃、五宝桃、二色桃、京舞子桃、撒金碧桃、红叶碧桃、菊花桃、碧桃（中国古老品种）、绯桃、照手红桃的园林观赏价值最佳,达80%以上;照手桃、照手白桃、寿红桃、白花山碧桃、绛桃、人面桃、红雨垂枝桃、鸳鸯垂枝桃次之,综合指数达70%～80%,分值较低的多为白花品种。运用层次分析法可有效地对观赏桃品种观赏性进行综合评价。     

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.