板栗低干矮冠多主枝开心形树体结构评价

为探讨低干矮冠多主枝开心树形对板栗产质性能的影响,以10年生‘金丰’板栗为试材,采用将整树冠层分层的方法,研究了低干矮冠多主枝开心树形的树体结构参数及不同冠层间板栗总苞的分布特征。结果表明:在垂直方向上,结果枝和总苞的分布主要集中在树体的中上部,下部有少量分布,其中结果枝和总苞均在1.0~1.5 m层间最多,而每果枝总苞数量在冠层两端最多。在水平方向上,发育枝、结果枝和总苞数量随冠层外移逐渐增多,集中分布于0.5~2.5 m的冠层范围,分别占总量的87.9%、89.9%和88.2%,其中结果枝和总苞在1.5~2.0 m的层间数量最多,体现了该树形立体结果的效果。该树形在保证坚果品质的同时,产量较自然开心形和自然圆头形提高30%以上。     

板栗总苞与坚果表型多样性及其相关关系研究

为揭示板栗总苞、坚果等表型性状的变异程度及不同表型性状间的相关关系,分别采用描述性统计分析法、方差分析法、Duncan多重比较法和相关分析法对部分板栗种质的总苞与坚果的10个表型指标进行了分析。研究发现:板栗总苞长度、宽度、高度及坚果高度、宽度、厚度6个性状的变异较小,变异系数均在5%~10%之间;总苞体积、总苞质量以及坚果质量、坚果体积4个性状的变异较大,变异系数多在10%~25%之间,表型多样性丰富,处于较高水平;不同种质间存在不同程度的表型差异;板栗总苞质量与总苞长度、宽度、高度及坚果高度、厚度、质量呈正相关,坚果质量与总苞质量及坚果长度、宽度、厚度呈正相关,与总苞长度、宽度、高度无显著相关关系;总苞发育与其内部坚果发育在质量上互呈正相关。     

优良板栗品种—粘底板

粘底板板栗是安徽舒城绿化公社常院一带的主栽品种,因其总苞内茸层较厚,坚果底座大而深嵌在总苞内,以致坚果成熟后总苞开裂,坚果不落;即使过熟(总苞落地)坚果仍附着于总苞内不掉,所以被当地群众称之为“粘底板”。粘底板幼树较直立,结果大树树形开张呈半圆形或圆头形。主干褐色,有灰白斑,枝条粗壮,黄褐色,芽大。新梢密被黄色茸毛,老熟枝条只有顶部有茸毛。叶片中等大小,为披针状椭圆形,先端渐尖,基部楔形。幼叶背面密被白色长茸毛,叶面沿叶脉有白色短茸毛,叶色深绿,叶面皱,具光泽。混合芽大而饱满,多着生干结果母枝顶端以下数芽(一般是1—4芽)。每一结果母枝能萌发2—4个结果枝(混合花枝),每一结果枝上有雌花穗     

适于北部山区栽植的板栗良种及栽培要点

<正>1良种1.1燕山红栗又名燕红。原株为40多年生的实生树,生长在北京市昌平县北庄村,故又称北庄一号。该品种树形中等偏小,树冠紧凑,结果枝比例高,早产丰产。总苞椭圆形,壳薄,刺束较稀,出籽率高。坚果果面茸毛少;果皮红棕色,富光泽,平均果重8.9g,果肉甜,糯性,含糖20.25%,含蛋白质     

几种化学调节剂及其组合对板栗雌花数量及结实性能的影响

用 BR、GA3 、PP3 3 3 、KH2 PO4 、H3 BO3 共 5种化学调节物质进行了叶面喷布试验 ,观察它们在板栗开花结果上的效应。结果表明 ,不同药剂、浓度及药剂组合对板栗母枝平均结果枝数、长度、每结果枝雌花序数 ,母枝平均雄花枝数 ,单果质量 ,三果率和空苞率的影响有明显的差异。综合考虑化学调节物质在提高板栗雌花量和果实产量 ,以及降低空苞率上的试验效果 ,最佳的化学处理为 BR0 .0 1mg· L-1 PP3 3 3 1g· L-1 KH2 PO4 7.5g· L-1 H3 BO3 5.0 g· L-1,可使板栗结果枝数目平均由 1.2个增加至 2 .833个 ,结果枝平均雌花数由 1.56 7个增加到 1.8个 ,平均空苞率由 30 .70 %降至 9.0 3%     

湖北省板栗地方品种果实性状研究

通过实地调查,对湖北省20个板栗地方品种的10个性状,利用SAS软件进行了板栗品种的Q型聚类及其10个性状的R型聚类分析.Q型聚类将20个板栗品种分成3组,每组都存在着明显的特点①油栗型品种,坚果小、晚熟、耐贮藏,适于炒食或贮藏保鲜,延后上市.②大果型品种,坚果特大,适于菜用或加工,中熟或中晚熟.③中果型品种,坚果中等大,成熟上市较早,适于鲜食.R型聚类分析揭示了性状之间的相对关系,把10个性状分成了3组,8个形质性状最先聚合在一起成为一组,2个数量性状彼此独立.坚果平均质量、总苞平均质量是不稳定的数量性状.根据总苞和坚果性状编制了湖北省板栗品种检索表,就湖北省板栗品种结构调整提出了建议.     

湖北省板栗地方品种果实性状研究

通过实地调查，对湖北省20个板栗地方品种的10个性状利用SAS软件进行了板栗品种前Q型聚类及其10个性状的R型聚类分析，Q型聚类将20个板栗品种分成3组，每组都存在着明显的特点：（1）油栗型品种，坚果小，晚熟，耐贮藏，适于炒食或贮藏保鲜，延后上市，（2）大果型品种，坚果特大，适于菜用或加工，中熟或中晚熟，（3）中果型品种，坚果中等大，成熟上市较早，适于鲜食，R型聚类分析揭示了性状之间的相对关系，把10个性状分成了3组，8个形质性状最先聚合在一起成为一组，2个数量性状彼此独立，坚果平均质量，总苞平均质量是不稳定的数量性状，根据总苞和坚果性状编制了湖北省板栗品种检索表，就湖北省板栗品种结构调整提出了建议。     

板栗空苞形成原因及控制对策

板栗空苞,俗称空蓬、“哑苞”,即球苞中的坚果不发育或仅留种皮。经过对河南桐柏县板栗产区的调查发现,板栗的空苞现象非常普遍,平均达到25%左右,有些高达40%以上,是影响板栗产量的重要因素,给栗农造成了极大损失。根据多年的实践和探索,笔者总结出了板栗空苞形成的原因及其一些控制措施。     

板栗总苞在树冠中的分布规律

通过对板栗总苞在树冠中分布规律和结果母枝不同部位芽抽生结果枝能力的研究提出：板栗的总苞集中分布在树冠表面０～５０ｃｍ的冠层内,存在着严重的结果表面化现象;其主要原因是内光照严重不足,结果母枝中部无芽和随着芽位的增加芽抽生结果枝能力逐渐减弱,改善树冠内膛光照条件和培养粗壮的结果母枝是板栗修剪的主要任务,在板栗修剪中的不宜采用短截的修剪方法。     

河北省太行山区核桃主要栽培品种综合性状研究

对不同核桃品种的树体性状、枝类组成、结实特性、果实外在性状、果实内在品质进行了调查研究,结果表明:绿岭、香玲、辽宁1号、辽宁3号和辽宁7号树高均在2.67～3.75m,短果枝占总结果枝量的50%以上,坚果外观美观,脂肪含量大于65%、蛋白质含量大于20%,适宜在太行山区发展。     

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.