银杏新品种‘泰山玉帘’

‘泰山玉帘’是从银杏种质资源圃中发现的1个枝条自然下垂的单株,经过嫁接繁殖试验所得。叶片有2种类型:一种为人字形叶片,中裂极深,可达叶片基底或接近基底;另一种叶片的中裂较浅或极浅,叶片呈扇形、窄扇形或半圆形,叶片上缘呈波状或齿牙状短裂。雌株,雌球花有长梗,梗端有1～2盘状珠座,每座生1胚珠,发育成种子。种子核果状,种核(即白果)较小,外种皮肉质,有白粉。10—11月果熟,熟时淡黄或橙黄色,有臭味。中种皮骨质,白色;内种皮膜质。     

银杏新品种‘金带’

‘金带’是对斑叶银杏进行枝条和植株优选,通过嫁接繁殖试验,选育获得的斑叶银杏新品种.主要特点是叶片为扇形,中裂较浅,叶缘浅波状,有长柄;叶片有黄绿相间的条纹,斑纹叶片底色绿色,其上间有黄色竖条纹.斑纹叶占全树全部叶片的40％～80％.雌株,雌球花有长梗,梗端有1～2盘状珠座,每座生1胚珠,发育成种子.种子核果状,近球形,外种皮肉质,有白粉.10-11月果熟,熟时淡黄或橙黄色,有臭味.中种皮骨质,白色;内种皮膜质.叶片春夏秋3季均能保持特色,可广泛应用于行道、公园、庭院、广场、旅游景点等.     

银杏新品种'夏金'

'夏金'系自众多黄叶银杏中经多年比较观察,从湖北省安陆市引进的黄叶银杏中优选所得.叶片为扇形,中裂极浅,叶缘浅波状,有长柄;春季叶片色泽金黄,至夏季叶片虽有个别转为黄绿,但大部分叶片依然金黄.雌株,雌球花有长梗,梗端有1～2盘状珠座,每座生1胚珠,发育成种子.由于该品种春、夏、秋三季叶色金黄,具有很好的观赏效果,又由于其繁殖容易,管理简单,应用于行道、公园、庭院、广场、旅游景点等,具有较高的推广价值.     

青钱柳种子物理方法处理及育苗技术研究

选择生长健壮的青钱柳单株为采种母树,当翅果由青变黄时采摘或者用农用胶膜平铺树冠下待种果被风吹脱落时人工清扫收集,种果集中后利用阳光晒干除去果翅和果梗。因青钱柳种子含胡桃酮抑制物致使其具有深休眠性,加上种皮坚硬不透水,造成种子发芽率极低仅2%左右。为了提高种子发芽率,播种前将种子用专用打磨工具除去部分硬壳层,以不磨破种皮为原则,再用多菌灵1000倍液消毒杀菌浸种3 d,第3 d捞干净漂浮在水面上的空粒种子。用自来水将种子冲洗三次后加40~45℃温水浸泡2 d,每天晚上换水1次,再用GGR生根诱导剂浸种1 d后沥干水分播种于苗床中。结果表明:处理后青钱柳种子发芽率可达70%。采用高密度撒播育苗方式当小苗长至二叶一心时按株距5~10 cm移植,可亩产根系发达达标苗3万株,为常规育苗2倍。     

日本落叶松种子园优良家系球花分布规律及花量调查

对日本落叶松种子园优良家系雌雄球花数量及在树冠上的分布规律进行调查分析。结果表明:日本落叶松雄球花在树冠垂直方向上分布差异极显著,下层和中层的数量显著多于上层,所占比例为83.39%,水平方向上南面的雄球花多于其他方向;雌球花在树冠不同冠层的分布无显著差异,中、上层的雌球花数量比下层多,东、南方向多于西、北方向;雄球花多着生在2,3 a生枝上,雌球花多着生在3,4 a生枝上,1 a生枝条上无花;不同无性系间雌雄球花数量差异显著,356号无性系的雌雄球花数量均为最多。     

乡土珍稀树种——蒜头果

1 形态特征 蒜头果(Malania oleifera Chun etLee.)为铁青树科(Olacaceae)常绿乔木,树高15～20 m,胸径30～40 cm.树干通直,树皮灰褐色,树冠广阔.单叶互生,卵形、椭圆形至长圆状披针形,长7～15 cm,宽2.5～4cm,基部及顶部渐尖,嫩叶有棕色浅柔毛,叶柄长1.5 cm,叶片搓烂有桃仁味.花两性,腋生,花小,10～15朵排成伞形花序或排泄成总状花序;单序或2～3序集生于短枝上端或小枝梢,总花梗纤细,长1.8～2.3 cm;萼4裂齿;花瓣4～5片,镊合状排列;雄蕊为花瓣数的2倍;子房上位,下部2室,每室有1悬垂的胚珠.桨果状核果,扁球形,径3～4.5 cm,高3～4 cm,形似蒜头,果皮肉质,顶部具尖头,基部稍收狭,每果有种子1粒,种子淡黄褐色,种壳木质,坚硬,种仁柔软,乳白色,胚乳丰富.     

辨清雌雄银杏

银杏属雌雄异株植物 ,栽植时必须做到雌雄的合理搭配 ,才能保证连年丰产 ,所以识别银杏雌雄是栽植时应该注意的问题。粗看银杏树 ,雌雄差不多 ,但只要仔细辨别 ,还是能从形态上予以区别的 :苗期的不同 :雄株侧枝与主是夹角内有一较大的叶片 ,雌株则没有。叶片的不同 :雄株叶片大 ,有较深的锯齿缺刻 ;雌株叶小 ,叶前端为浅裂。花与花芽的不同 :雄花序为柔荑状 ,外形似桑椹 ;雌花长在花梗顶端 ,分作两叉 ,外形如火柴梗。此外 ,雄花芽大而饱满 ,顶部稍平 ;雌花芽瘦而稍尖。树冠的不同 :同龄树 ,雄树比雌树高大。雄树形成树冠时间较晚 ,枝条层次…     

抗寒品种--红果女贞

红果女贞为木犀科女贞属。分布于罗霄山脉1 5 0 0m的高寒地区 ,常绿灌木或小乔木 ,高 5～ 7m ,嫩枝及花梗紫红色 ,叶椭圆形 ,长 6～ 8cm ,宽 3～ 4cm ,淡紫红色。顶生圆锥花序 ,长 6～ 8cm。果长椭圆形 ,假浆果核果状 ,种子 1枚。花期 5月 ,果期 8月 ,枝头红果累累 ,延至 1 0月不落。该品种适应性强 ,生长快 ,萌芽率高 ,耐修剪 ,能耐 - 2 0～2 2℃的低温。可抗二氧化硫、氯气、氧化氢气。在pH值 8～ 9的偏碱性土壤生长正常。繁殖 :1 .种子繁殖 :种子采收后 ,经过 5～ 7d的后熟期 ,然后擦去种皮 ,在清水中淘出种子 ,稍晾干 ,与湿润的细沙混…     

五味子栽培技术

五味子为多年生落叶木质藤本,长6米～8米。嫩枝红棕色,老枝暗灰色,表面微开裂,具有香气。叶生在幼枝上,单叶互生,叶柄细长,叶片卵形、倒卵形或宽椭圆形,尖端尖,基部楔形。花单性,腋生,偶见雌雄同花,有香气。浆果球形,直径5毫米～7毫米,成熟时呈红色。每个果实含1粒～2粒种子,种皮黄褐色。花期5月～7月,果熟期9月～1O月...     

无患子育苗技术

无患子又名皮皂子、菩提子、油患子,属无患子科无患子属落叶乔木,高可达25 m.枝开展成广卵形或扁球形树冠.树皮灰白色,平滑不裂;小枝无毛,芽两个叠生.羽状复叶互生,小叶8～14枚,卵状披针形至长椭圆形,长6～13 cm,宽2～4 cm,顶端渐尖,基部宽楔形,两侧不等齐,全缘,无毛或仅在背面中脉上有微毛.圆锥花序顶生,主轴和分枝有茸毛;花期为5～6月,开放时直径3～4 mm萼片和花瓣各5片,边缘有小睫毛;花瓣的瓣柄内侧有被长柔毛的鳞片2片.核果由子房的1室发育而成球形(未发育的2室多残留基部),9～10月成熟;熟时褐黄色,表面有棱型网状突起,直径2 cm;种子球形,黑色光亮,坚硬.     

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.