巴蜀地区的杨柳科植物(二)

巴蜀地区（原四川省地区），杨柳科植物包含3个属、93个种（以及大量的天然杂种和栽培品种），即杨属（16种），原柳属（6种），柳属（71种），同时广泛分布于海拔约5000米以下的各个地区。本文包括分属检索表和各属的分种检索表，及所有种和种下分类单位的正名、异名、地理分布。     

巴蜀地区的杨柳科植物(一)

巴蜀地区（原四川省地区），杨柳科植物包含3个属、93个种（以及大量的天然杂种和栽培品种），即杨属（16种），原柳属（6种），柳属（71种），同时广泛分布于海拔约5000米以下的各个地区。本文包括分属检索表和各属的分种检索表，及所有种和种下分类单位的正名、异名、地理分布。     

杨树起源与进化的探讨

杨树(杨柳科杨亚科)包含两个属(即胡杨属、杨属)、约50余个天然种(以及繁多的天然杂种和人工杂种),自然分布于热带非洲和大致从北纬19度至70度的北半球;胡杨属约8种,间断分布于赤道非洲、古地中海地区和北美洲东南部;杨属约40余种,大致产于北回归线与北极圈之间的亚洲、欧洲、非洲和北美洲。杨柳科植物的近期祖先可能在白垩纪初期起源于西冈瓦纳古陆,并通过两个中间环节(即古杨群和古柳群)逐步分别发展为现存的杨树(即胡杨属与杨属)和现存的柳树(即原柳属、钻天柳属与柳属)。古杨群(杨树的直接祖先)可能在白垩纪中期起源于西冈瓦纳古陆;后来它扩散至有关各地(特别是北方的劳亚古陆),并在迁移的过程中进一步分化发展。胡杨属可能在白垩纪中、晚期发生于非洲陆块,并逐步扩散至劳亚古陆;后来,统一的胡杨属区系因劳亚古陆的断开和撒哈拉大沙漠的形成而被分割为远离的、独立发展的几个部分。杨属可能在第三纪中、晚期先后发生和分化于古地中海东部地区;后来扩散至欧亚大陆并陆续通过白令地区迁移至北美大陆。文中还提供了有关植物的属、种一览和杨柳科植物亚科与属的检索表。     

西藏的杨柳科树木

本文包括一些分类单位的分类学处理，分属检索表和各属分种检索表，西藏地区杨柳科植物名录（4属83种的正名、异名和地理分布）。     

原柳属次级区分的探讨

原柳属Pleiarina Rafin.隶属于杨柳科柳亚科Salicaceae subfam.Salicoideae;在柳亚科的系统发育中,它体现了一条单独的演化路线、代表了一个明确的谱系分枝;它自然分布于大约从南纬52度至北纬70度的非洲、南美洲、欧洲、亚洲、北美洲的广大地区,广泛生长在热带、南温带、北温带、北寒带(南缘)的各个地带。原柳属约有56个天然种,本文中被区分为2个亚属、6个组、3个系;原柳亚属Subgen.Pleiarina包含4个组,即四籽柳组Sect.Tet-raspermae,原柳组Sect.Pleiarina(包含原柳系Ser.Pleiarina,腺柳系Ser.Glandulosae,锐叶柳系Ser.Acmophyllae),马达柳组Sect.Madagascarienses和锦江柳组Sect.Fangianae;五蕊柳亚属Subgen.Lygus包含2个组,即五蕊柳组Sect.Lygus和三蕊柳组Sect.Amygdalinae。编写了亚属、组、系的检索表。提供了原柳属植物种类一览,包括它们的正名、异名、文献引注、地理分布等。     

吉林省杨柳科植物种类的调查研究——关于杨柳科植物的研究之二

确认吉林省杨柳科植物计3属53种。其中:杨属13种1变种;钻天柳属1种;柳属34种4变种。并对其属种的分类检索以及三种杨树种的识别等,提供了补充。     

云南栎木小志

壳斗科树木全世界有8属近千种;中国产7属约300种;云南产7属约170种,占全国大半,且属类齐全。本科树种在云南统称栎木,在云南分布甚广。作者等多次在云南采集本科大量木材标本,测试容重、物理力学性质,并作了耐腐性试验。本文将云南栎木分为15类,以一、分类检索表;二、各类商品材类名及树种;三、分类材性表、主要用途及商品材一、分类检索表1.散孔材至半环孔材,管孔散布;轴向薄壁组织星散——零合;木射线具细、窄、宽三型,     

湖南壳斗科植物的研究

本文对湖南壳斗科植物的分类和地理分布作了较详细的论述,对该科几个比较难鉴别的属(拷属、石栎属、青冈属)作出了分种检索表,同时论述了2个新种,17个湖南新分布种。作者探讨了该科地理分布型,並认为湖南是壳斗科多种地理成分的过渡和汇集地区,基于上述研究,提出了对壳斗科资源应进行合理经营、利用和保护的建议。     

昆明市桂花品种资源调查

昆明气候特殊,近几年城市扩展迅猛,新增绿地较多,因此,重新调查昆明市区的桂花品种,发掘具有本土特色品种工作尤为重要。依据向其柏、臧德奎的桂花品种分类检索表,对昆明市五城区的桂花品种资源进行调查,共鉴定出59个桂花品种,其中四季桂品种群7个,银桂品种群29个,金桂品种群16个,丹桂品种群7个,包括疑似新品种10个(新记载8个,翟丽丽记载2个,均为银桂品种)。编制了各品种群的分类检索表,描述了8个疑似新品种形态特征,并总结了昆明市区桂花品种资源特点。     

树木营养器官在分类上的研究与应用

应用营养器官进行树木分类是一种理想的新尝试 ,其目的是要改变以生殖器官为主的传统分类方法 ,使之更富于实用性。为此作者对我国 2 1 2科 1 4 0 0余属 ,近 1× 1 0 4 种树木的叶及叶脉、枝条、髓心的质地和结构、维管系统 (叶隙、叶迹 )、芽体及叶痕等进行了较为深入的研究 ,认为我国树木营养器官可分为 7个类型 ,并对每个类型进行了科属 (含种群 )综合检索表及各科分属检索表的编制工作 实践证明只要能确切掌握树木的各个分类依据 ,这种设想是完全可以实现的。还以植物界各个分类层次 (门、亚门、科、属 )为基础 ,从营养器官上作了总结、归纳和分析 ,而且分析了脉序式样和维管系统在植物系统发育中的指示作用 ,补充和丰富了传统分类理论     

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.