湖南杜鹃属植物野生资源多样性调查

对湖南杜鹃属植物进行野外调查、资料收集、标本鉴定,确定湖南自然分布杜鹃属植物62种1变种,隶属5亚属8组16亚组,其中特有种有13种.湖南杜鹃属植物资源种类较多,珍稀特有植物丰富,表型性状多样.     

贵州百里杜鹃保护区的杜鹃属植物种类及其观赏特性研究

贵州西部百里杜鹃保护区的杜鹃属植物种类关系到其保护区的价值。经过调查研究,该保护区计有杜鹃属植物33种(含变种),分属于5个亚属,占贵州现有杜鹃属植物种类111种的29.73%;并发现了西昌杜鹃和白花杜鹃两个贵州的新分布种;进而从园林的角度,论述了这些杜鹃属植物种类花的颜色、大小及花期等的观赏特性。     

湖南杜鹃花资源及其开发利用

论述了杜鹃属植物的分类、分布、演化及开发利用历史,着重探讨了湖南的自然生态环境及其与杜鹃属植物分布繁衍的关系,分析了杜鹃属植物的利用前景.结果表明:杜鹃属植物是全球广布的木本植物,历经一千多年的繁衍,形成了种数达1000种的种群;中国是名副其实的杜鹃花王国,约分布有570种,目前,仅新疆和青海两省未见野生杜鹃踪迹,全国绝大部分省区均有原生杜鹃生长,中国喜马拉雅地区,即以四川·西藏为核心的区域是中国杜鹃花的多度中心和多样化中心.经考证,湖南产野生杜鹃53种1亚种1变种,隶属于4个亚属,湘西南·湘南·湘西北是湖南杜鹃的主要分布区.同时,提出了开发利用野生杜鹃的思路,建议引种驯化先行,以杜鹃的种植创新为目标.     

四川栗子坪国家级自然保护区杜鹃花属植物多样性与分布特点

通过对四川栗子坪国家级自然保护区杜鹃花属植物的野外调查及资料收集整理发现,保护区现有杜鹃花属植物3亚属,5组,10亚组33种,2个亚种,1个变种,共计36种;其区系类型以中国东部-喜玛拉雅分布型和东亚分布型为主要特征;四川特有8种,处于濒危等级的杜鹃花8种,亟需对石棉杜鹃和冕宁杜鹃进行补充调查和保护;杜鹃花物种在保护区主要分布于海拔1 800～4 000 m中高低海拔区域,物种数量随海拔增加呈先增加后减少的趋势;保护区杜鹃花属植物有较高的景观应用价值,银叶杜鹃、繁花杜鹃和团叶杜鹃等可作为新品种创制的优良父母本,建议在保护的基础上加大杜鹃花新品种创制、繁育与开发利用研究工作。     

宁波市杜鹃属植物资源调查

2012-2018年采用典型地块、典型线路详查为主,全面踏查为辅的方式对宁波市杜鹃属植物资源进行调查.结果 表明,宁波市共有野生及习见栽培的杜鹃属植物9种1变种1变型,其中野生种6种1变种1变型,习见栽培种4种.从水平分布看,有广域种、区域种、局域种和微域种4种类型;从垂直分布看,只分布于海拔700 m以上的有华顶杜鹃...     

杜鹃红山茶在原产地生长特性的调查报告

杜鹃红山茶（Cammellia azalea）是一种珍贵珍稀濒危植物，它属山茶科山茶属。其叶、花、枝条都有很高的观赏价值，花期长的特点是其它茶花所没有的。目前只在广东省阳春市境内发现少量零星分布。本文通过对杜鹃红山茶在原生地的立地条件及其叶、花、果生长特性等的调查，为今后更好地开发利用提供基础依据。     

湖南杜鹃属植物种类及引种适应性初探

在对湖南杜鹃属植物的野外调查、资料收集、标本鉴定的基础上,对其在湖南省森林植物园的引种栽培适应性进行研究。湖南产杜鹃属植物57种1变种,隶属5亚属8组14亚组,其中映山红亚属数量最,多达21种,占36.21%;湖南省森林植物园引种保存湖南杜鹃属植物38种,其中杜鹃亚属2种、常绿杜鹃亚属11种、马银花亚属8种、羊踯躅亚属1种、映山红亚属16种。引种栽培效果表明:马银花亚属在引种栽培中适应性最强,8种均表现为优良;原生分布海拔低的物种适应性高于相对海拔高的物种。分析探讨湖南杜鹃属植物在长沙地区的适应性,提出杜鹃属植物异地保育和开发建议。     

杜鹃花属植物在广州园林绿地中的应用

以广州市的10个城市公园、10条城市干道和10个居住区为研究对象,应用实地分区抽样法。调查和记录所属区内出现的杜鹃花属植物种类、出现频率、配置方式和生境特点。结果表明,广州市绿地露地中应用的杜鹃花属种类常见的有锦绣杜鹃（Rhododendron pulchmm）和凤凰杜鹃（R. pulchrum var. phoeniceum） 。偶见种为映山红（R．simsii）和皋月杜鹃（R．indicum）;毛白杜鹃（R．mucronaturn）本次调查未见,盆栽植物主要有西洋杜鹃（R．hybridum）。杜鹃花属植物在公园露地应用较广。居住区有少量应用。但道路绿化带应用极少。公园、居住区的应用方式较为多样,花期时的观赏效果甚佳。文章简要评价了广州部分以杜鹃花为配置材料的景观特点,并分析了杜鹃花属植物在广州市绿化应用中的优势及存在的问题;提出加强野生杜鹃花的引种驯化和杜鹃花属植物的抗逆性选育种研究。促进乡土杜鹃花种类的驯化和应用的建议。     

基于层次分析法的浙江大盘山自然保护区杜鹃花属植物资源应用价值评价

基于对大盘山自然保护区杜鹃花属植物的野外调查,综合考虑观赏价值、生态学特性、应用潜力和稀有度因素,筛选出14个评价因子,构建了层次分析模型,对大盘山自然保护区9种杜鹃花属植物进行应用价值综合评价。结果表明,在观赏价值、生态学特性、应用潜力和稀有度4个影响因子中,观赏价值最能影响人们对杜鹃花属植物应用价值的评价,其次是应用潜力、生态学特性和稀有度。9种杜鹃花属植物的应用价值从高到低依次为云锦杜鹃华顶杜鹃杜鹃马银花丁香杜鹃羊踯躅满山红猴头杜鹃麂角杜鹃。文中还就杜鹃花属植物的野生资源驯化以及资源评价中约束层指标的选取等问题进行了讨论。     

祁连山杜鹃花属植物资源调查及繁殖技术研究

为了进一步开发利用祁连山野生植物资源,调查研究了杜鹃花属植物形态特征、分布范围、自然繁殖、扦插繁殖和移栽生长特性。结果显示：（1）祁连山杜鹃花属植物共有4种,分别为青海杜鹃、烈香杜鹃、头花杜鹃和百里香杜鹃。（2）在自然条件下,4种杜鹃花属植物均以根蘖苗繁殖,播种后发芽率均为0。（3）采集4种杜鹃花属植物硬枝扦插繁殖时,ABT生根粉浓度10mg/L处理的插条生根率、生根数、根系长度和新梢长度均最高。（4）4种杜鹃花属植物扦插苗移栽后,成活率70.23%～85.80%、新梢数4.73～6.74个/株、新梢长度34.22～43.35cm、保存率67.38%～83.21%。     

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.