几种野牡丹属植物系统发育关系的初步研究

采用nr ITS和叶绿体基因间隔区trnL-trnF的序列,初步研究分布于广东省的野牡丹属的6个物种,即展毛野牡丹(Melastoma normale)、野牡丹(M.candidum)、多花野牡丹(M.affine)、细叶野牡丹(M.in-termedium)、地稔(M.dodecandrum)、毛稔(M.sanguineum)和1个原产印度的印度野牡丹(M.malabathri-cum)及其白花变种(M.malabathricum var.alba)的遗传关系。结果表明,展毛野牡丹、野牡丹、多花野牡丹、细叶野牡丹和毛稔这5个物种具有完全一样的nr ITS和叶绿体基因间隔区trnL-trnF序列,表明它们之间存在非常近的亲缘关系。印度野牡丹在nr ITS序列上与前5个物种序列相同,但在叶绿体trnL-trnF序列上具有1个碱基的差异,表明它与这些物种之间存在非常近缘的关系。地稔与其他几个物种无论在nr ITS序列还是在叶绿体trnL-trnF序列上都差异甚大。     

不同栽培基质对3种野牡丹属植物生长的影响

为筛选野牡丹属在不同栽培基质上生长的差异,促进野牡丹属植物在城市园林中的推广应用 , 以 3 种野牡丹属植物（白花印度野牡丹 Melastoma candidum var. albiflorum、野牡丹 M. candidum 和毛稔 M. sanguineum）为试验材料,设置了 4 种不同比例泥炭土、蛭石和椰糠混合物 / 料和黄泥栽培基质处理, 比较 3 种植物的净生长量和生物量。研究结果表明,3 种野牡丹属植物苗高、冠幅、叶面积净生长量均以 黄泥栽培基质处理组较高,生长促进效应优于泥炭土、蛭石和椰糠的混合比例处理组;其地上部、地下 部生物量积累也均以黄泥栽培基质组最高。隶属函数分析结果表明,促进 3 种野牡丹植物生长效应的栽 培基质均为黄泥。     

湖南省野牡丹科野生观赏植物初步研究

野牡丹科(Melastomataceae)观赏植物是近年来国际上流行的花卉。我国野牡丹科植物资源丰富、品种繁多,然而对其观赏价值的开发目前尚属空白。本文在对湖南省野牡丹科观赏植物资源进行初步调查的基础上,结合它们的株型、花色、花期、叶形和果形等审美要素对其观赏价值的应用加以研究。结果表明:湖南省大多数野牡丹科植物可作为观赏栽培,需要有效的保护和合理开发利用。     

羊蹄甲属植物引种适应性、观赏性综合评价

文章在野外调查、引种驯化试验的基础上,采用层次分析法,通过构建引种难易、生长状况、生态适应性、观赏效果4个评价准则,以及11个评价因子的综合评价模型,对30种羊蹄甲属植物开展引种适应性、观赏性的综合评价。结果表明:单蕊羊蹄甲、粉叶羊蹄甲、首冠藤、白花羊蹄甲、鞍叶羊蹄甲等综合得分4.4以上的11种植物易于驯化,观赏性价值较高,可大规模开发利用;孪叶羊蹄甲、囊托羊蹄甲、石山羊蹄甲等得分3～4.4分者可适度开发;Bauhinia grandidierri、Bauhinia cunninghamii、Bauhinia hookeri等得分低于3分者暂时不推荐开发。     

野牡丹属植物对大肠杆菌的抑菌效果

以多花野牡丹(Melastoma.affine)为试验材料,以无菌水为提取剂,通过纸片扩散法对多花野牡丹水提取物进行大肠杆菌的抑菌试验。采用水浴时间、水浴温度、料液比3因素3水平正交试验筛选野牡丹属(Melastoma)植物叶抑菌物质的最佳提取条件,结果表明:提取温度60℃,浸提时间2 h,料液比1∶30为最佳提取条件;并采用最佳提取条件对部分野牡丹属植物叶水提取物的抑菌能力进行比较,结果表明:野牡丹属植物叶的水提取物抑菌能力大小为:毛菍(M.sanguineum)>枝毛野牡丹(M.dendrisetosum)>细叶野牡丹(M.intermedium)>多花野牡丹。     

秋石斛品种资源的评价与筛选

秋石斛是兰科植物中极具观赏价值的切花种类,为加速我国秋石斛产业发展,本研究对16个秋石斛品种的营养生长、生殖生长、抗逆性等性状分季节进行调查,并结合商业价值和市场销售情况,采用层次分析法和聚类分析法对秋石斛品种资源进行评价与筛选。结果表明:4个一级指标中,经济效益和观赏性状权重系数较高。经济效益、观赏性状、抗逆性、开花特性指标中权重最大的二级评价因子分别为市场价值、花姿、抗病虫、花量。合成权重较高的5个因子依次为市场价值、花姿、培育成本、水培保鲜期、抗病虫。16个品种聚类分析后分为4档,第一档为‘三亚阳光’、‘水晶’、‘金如意’、‘枫叶’等4个品种;第二档为‘怪脸’、‘中华红’、‘美洋洋’、‘紫霞’、‘红霞’、‘四面佛’等6个品种;第三档为‘彩虹’、‘水芙蓉’、‘迷你红白’、‘明珠’、‘浪迹天涯’等5个品种;第四档为‘卡哇伊’;‘三亚阳光’综合评价得分(CAV)最高,较其它15个品种更具商业开发和产业化生产价值。     

广州发展公园花境植物综合评价

为构建适合广州地区的花境植物综合性评价体系，本研究对广州发展公园中的 7 组花境的 植物进行调查，采用层次分析法，从观赏性、生态适应性、安全性和经济性 4 个方面，提出 23 个花境 植物综合评价指标，构建花境综合评价体系，并对广州发展公园的 57 种花境植物进行评价。基于花 境的特点，本评价体系中观赏性权重最高，生态适应性权重排序第二。经过综合评价，筛选了赤苞花 Megaskepasma erythrochlamys、巴西野牡丹 Tibouchina semidecandra、蝎尾蕉 Heliconia metallica、红花檵 木 Loropetalum chinense var. rubrum 等 36 种综合应用价值较高的花境植物。在本评价体系中，观赏性和 生态适应性是评价花境植物的重要指标，这与前人研究结果一致，也与花境营造注重“自然、美观”和 “可持续”的特点相吻合。综合评价等级为 I 和 II 级的 36 种植物适合在广州地区推广使用，综合评价等 级为 III 级的 21 种花境植物主要为一二年生花卉，因此在实际应用时，限制条件较多。     

基于层次分析法的杜鹃品种综合评价体系的建立

根据杜鹃品种的观赏特性,运用层次分析法初步建立杜鹃品种综合评价体系。评价发现花期长短、花径和花色是评价杜鹃品种观赏价值的重要因子,共占据总权重46.72%。利用该评价模型对50个杜鹃品种进行观赏价值综合评价,将50个品种分为4个等级。其中得分>4.7的I级包含了‘红阳’、‘红苹果’、‘大吉祥’、‘丹顶’、‘霸王红’、‘常春3号’等6个品种,观赏价值高。     

中国特有种枝毛野牡丹传粉生物学及繁育系统研究

对海南吊罗山国家级自然保护区枝毛野牡丹(Melastoma dendrisetosum)的开花进程,访花昆虫、访花行为、访花频率以及气候条件等进行观察记录,同时检测了花粉活力、柱头可授性、花粉胚珠比、繁育系统,并分析其致濒机制。结果表明:枝毛野牡丹是典型的异型雄蕊植物,5:30—8:30逐步开放,8:30—9:00完全开放,19:00花朵闭合,单花开放时间为12—14 h,群体花期36±2 d,无花蜜。访花昆虫主要有木蜂科、条蜂科、蚁科、食蚜蝇科的昆虫,最有效传粉昆虫为木蜂科昆虫。自然与人工授粉、套袋等试验结果表明,枝毛野牡丹不存在主动自花授粉、无融合生殖的生殖保障现象,为自交亲和的异交种,需要昆虫传粉,枝毛野牡丹繁育系统是兼性自交。枝毛野牡丹相对生殖成功率低仅为0.035,主要限制因子为花粉限制和传粉者限制。     

基于层次分析法的4种山茶科植物观赏价值评价

应用层次分析法,对猪血木(Euryodendron excelsum)、杜鹃红山茶(Camellia changii)、越南抱茎茶(C.amplexicaulis)、石笔木(Tutcheria championi)4种山茶科植物的树形、花、叶和果进行观赏价值综合评价,结果显示:在树形、花、叶、果4个影响因子中,花因子最能影响人对植物的评判,其次是树形、叶,最后是果;4种植物中,最佳观树形植物是猪血木,最佳观叶、观花植物是杜鹃红山茶,最佳观果植物是石笔木。4种植物的综合观赏价值从高到低依次为杜鹃红山茶越南抱茎茶猪血木石笔木。     

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.