世界竹亚科各属的考订(之六)

Ⅲ.竹亚科各属的考订(续) B.(竹禾)类之部 (竹禾)类是草本竹型禾草(herbaceons bambusoid grasses)的总称。它们在外貌上大都与普通禾草并无显著差异,但其植物体在微观方面(例如叶片内部的解剖结构、叶片表皮细胞和硅质细胞的形态、微毛细胞、气孔两侧的副卫细胞、胚的类型以及幼苗等)则是与竹类相同,而和一般禾草迥然有别的。它     

世界竹亚科各属的考订(一)

前言竹类植物虽多为木本,但亦有少数草本或近于呈草本习性的种类,一般称为草本竹型禾草(herbaceous bambusoides grasses,此间简称为“(竹禾)类”),经新近从其形态与解剖上的研究(Calderón et Soderstrom,1973),认为它们亦应列入竹亚科之中。自1788年11月瑞典人A.J.Retzius发表箣竹属的先驱属名Bambos以来,已将有200年,世界各国学者所发表过的竹亚科之属名,迄今已在120属     

竹类植物根部解剖的初步观察

我国竹类植物分布广泛,种类繁多。黄河流域以南都有天然分布。全国有500多种竹子,它们分属于大约40个属。竹类植物一些种类的鉴别,部分属及属以上某些价层的划分还没有得到完善,合理地解决。我们通过对国产在竹类植物的系统和分类上具有一定代表性的34种40余份竹子标本(分属于19属)的根部解剖观察,得出初步结论:根据竹类植物根部解剖特征可将竹类植物划分为两大类群,即散生竹类和丛生竹类。这两大类群的根解剖性质上又与目前按竹子花序划分的两大类群(箣竹超族和北美箭竹超族)密切相关,它从另一个侧面说明按花序建立的竹类植物的系统可能是符合自然规律的。但是,某些属(如(竹思)(竹劳)竹属、悬竹属等)根的解剖式样与其它属有明显的差异,这说明竹子的形态、结构等等方面具有更多的复杂性和多样性。某些竹种在根的解剖上有着具体而微的特征,因此,竹子根部解剖性质可作为鉴别某些竹类和划分许多竹属的依据,同时也可作为建立竹子自然系统的参考。     

论竹类起源

本文从竹类进化、原始类型、分布中心三方面对起源问题进行探讨,并综合申述原始种与进化种的特性,以便为生产与科研提供参考。一、从竹类进化看起始类型竹类植物有木本、草本之分。全世界有木本竹属78属,计1400多种,草本竹属29个属170余种,分布亚洲、南美、北美、非洲、澳洲。我国有42个     

竹材—印度制浆造纸工业主要的纤维原料

竹类是高而乔木状的草本植物,属竹亚科(Bambusace)隶禾本科(Gramineae)。竹生长如灌木或乔木,罕为草本。杆木质,形高而直立或攀援。竹最初起源于热带,在雨季带的森林中生长最茂盛,在那里竹子发育可以达到最大限度;在温带地区则缩小而成小灌木;而在海拔3657.6m 的雪线地方如南美洲安达斯山上,则成“草本”。     

慈竹一新变型和镰序竹属新异名

本文报道了禾本科竹亚科慈竹属慈竹一新变型——紫条纹慈竹Neosinocalamus affinis(Rendle)Keng f.f.purpureo-striatus Yi。本变型幼秆下部节间绿色而间有宽窄不等的紫色纵条纹,与原变型有明显区别。花序小型、花序轴短等特征仅是量变,不足为属级划分标准。因此,岩竹属应是镰序竹属的一个新异名。     

有趣的藤本竹

对于竹子,一般人只知高大的龙竹,刚直的金竹,而对与众不同的藤本竹却知其不多或不知。本文的话题就谈谈藤本竹。藤本状竹类是竹亚科植物中一个特殊类群,此类竹的直径通常为1至3厘米,秆长却可达10至30米甚至更长,似藤一般攀附于其它乔木之上。它不具卷须一类的攀援器官,也不能作螺旋状缠绕,所以稍部常悬垂至地面,有些地区群众多以“吊竹”相称。在没有乔木的地方,它们则匍伏于地面,连绵成片。中国藤本竹类有藤竹属,梨藤竹属,长穗竹属、悬竹属和新小竹属等约5属20种,另外,有空竹属、薄竹属、思劳竹属、泡竹属和单枝竹属等约15种为半攀援状竹类。它们大都分布在热带及南热带高温多雨的低海拔河谷地区,云南则是中国藤本竹类分布最集中的地区。它们的习性是在对营养空间的竞     

竹子染色体计数初报

竹子是禾本科(Gramineae)竹亚科(Bambusoideae)竹类植物的总称。全世界约有78属1400多种,生长在热带和亚热带地区。我国地处世界竹子的分布中心,是主要产竹国之一。 竹子细胞染色体方面的研究,据文献所查,国外已有60多年的历史,对许多种和变种、类型作了染色体计数,而国内除许建昌教授(台湾)外,严天民、张光楚等近年也有报道,到目前为上,约有29属的150多种和变种、类型有染色体资料。     

平阳县竹类资源区系分析及分布特征研究

对平阳县的竹类资源调查表明,该区域有竹类资源11属52种,其中原生竹种有10属30种,外引竹种有5属25种(含变种、变型);该区域竹类丛生竹种和乔木状竹种占相对优势地位,分布具有明显热带分布特点,兼有温带分布性质,显示竹类区系过渡性质,竹类区系更接近福建中北部区系类型;按竹子分布现状,该区竹子水平分布可划分为两小区,东南丛生竹区和西北散、混竹区。     

云南珍稀濒危竹类植物资源现状及保护对策

云南是中国竹类植物分布最丰富的地区,原始属种高度集中,生态类型齐全,全省分布广泛,属种种类丰富,其中53种为珍稀濒危竹种。文章介绍了云南珍稀濒危竹类植物的资源状况和保护现状,提出了保护云南珍稀濒危竹类植物的建议。文章认为应将云南分布面积在2 000 hm²以下的竹种纳入极小种群植物保护之列,并构建极小种群野生植物的种群生态学和保护生物学理论体系;同时保存和扩繁云南竹类极小天然种群,缓解濒危态势。     

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.