香格里拉虎跳峡镇核桃种质资源坚果表型特征多样性分析

对香格里拉虎跳峡镇79株核桃单株坚果表型特征的13个表型描述性状及8个数量性状进行测定分析和多样性研究.结果表明,该区域核桃坚果的形状、仁色的Simpson多样性指数较高,核桃拥有坚果形状表型特征描述的10种类型,表现出较大的多样性和丰富性,以扁圆球形、圆球形和长扁圆球形为主.种仁颜色主要以灰白和黄白色为主,占50.6...     

湖北麻城早熟油茶果实性状研究

湖北麻城是我国油茶主要产地之一,拥有十分珍贵的早熟油茶种质资源。为了科学评价该种质资源的多样性,以便对其进行更好的保护与开发利用,文中从该地的实生早熟油茶群体中选取50株油茶样株,分单株采集样品,对其果实成熟期、果实颜色、果实形状及果实数量性状进行了观测。结果表明:该地早熟油茶果实的成熟期为9月下旬至10月上旬;果实颜色主要有青色、红色、黄红色和青红色;果实形状有橄榄形、卵形、球形和桔形4种,其中以球形为主;果实12个数量性状的变异系数介于12.21%~42.19%之间,其中,单果籽粒数的变异系数最大;果实12个数量性状的多样性指数介于1.296~1.706之间。以上结果表明,该地早熟油茶种质资源的多样性较为丰富。     

核桃实生群体物候的观测

为给核桃抗晚霜品种的选育和晚花性状的分子辅助选择研究奠定基础,对泰安地区核桃F1实生群体的物候期进行了连续4年的观测。结果表明:核桃实生群体从3月中下旬开始萌动,3月下旬进入萌芽期,4月初至5月初随着叶片展开、新梢生长,混合芽中的雌花及枝条上的裸芽雄花陆续开放,8月下旬至10月初果实成熟,10月中下旬至11月上旬进入落叶期;核桃的物候特征是不同单株固有的遗传特性,不同年份其物候期不尽一致,但各单株上出现的先后次序是相对稳定的,而且,核桃实生群体中不同单株间的各物候时期的变异系数较高,这为晚花抗晚霜优良单株的选择提供了丰富材料。     

云南鲁甸避晚霜核桃优良单株选择

为使核桃避开晚霜危害,选育避晚霜新品种,以核桃物候期为指标,综合考虑其丰产性、坚果品质和抗逆性等来进行避晚霜核桃优良单株的选择。深入鲁甸县内9乡3镇逐乡逐村进行调查,采用群众荐优和实地调查相结合,对大约3 000棵不同树龄(均不小于15 a)的核桃树进行了调查分析,经预选、初选、复选和决选,最终选出12株避晚霜核桃优良单株,各决选优株芽萌动期与该区域主要栽培品种‘鲁甸大麻1号’相当或晚,比‘云新90303’晚25 d以上。有5个优株的芽萌动期在4月上旬,优株号分别是L161、L185、L343、L353和L455,萌芽最晚的L161,在4月16号芽才开始萌动,比‘鲁甸大麻1号’晚27 d,比‘云新90303’晚近2个月。核桃品种表现为萌芽晚这一价值特性,在鲁甸核桃生产上有较高推广应用价值。     

铁线莲品种物候期调查及分析

对28个品种的铁线莲在江苏句容的生长情况进行了物候期调查分析.结果表明,在供试的铁线莲品种中绝大部分品种是属于多年生落叶的木质藤本,常绿品种极少.在所观察的28个品种中,发芽期大都集中在2月中下旬,展叶期集中在2月24日至3月28日或是3月7日至4月11日,花苞萌动期则大部分集中在3月28日～4月26日.第1朵花的开花期在4月下旬,大部分品种的单朵花序开花持续时间较短,为5～11d,群体开花持续时间长,可从4月中下旬或5月中上旬一直持续到8月中下旬、9月中下旬或到10月中上旬不等,盛花期多在4月中下旬至5月中下旬.其中品种‘Souvenir du Capitaine Thuille ux’的群体开花持续时间最短,为4月26日至5月27日,品种‘Fireworks’的群体开花持续时间最长,从第1朵花到断断续续最后1朵花的时间为4月27日至11月21日.这28个铁线莲品种的花颜色鲜艳,有蓝色、紫色、粉红色、紫红色、白色等,且雌雄蕊多数,花的着生方式多为顶生或腋生,花瓣数基本一致,多为6瓣.种子为瘦果聚集成头状并具有长尾毛.     

黑莓与树莓品种在南京地区的物候期观测

通过定株、定期对14个黑莓、树莓品种的物候期进行观察,基本掌握了各品种在南京地区的物候期和各生育期维持的时间,为其优良品种的推广利用提供了依据.调查结果显示:不同品种黑莓与树莓各物候期存在差异,总的来看,黑莓品种一般在2月中下旬萌芽,3～4月展叶,4月中下旬至5月中下旬开花,花期平均(28.67±5.98)d,5月坐果,果实6月上旬至7月上中旬成熟,果熟期(28.78±6.44)d;树莓品种多集中在3月上中旬萌芽,4月下旬至5月上旬开花,果实5月下旬至6月下旬成熟.     

草履蚧的生物学特性及防治

草履蚧是杨树、法桐、核桃的主要害虫,在河北省邢台地区1年发生1代,以卵在寄主附近的土中越冬.翌年2月上旬至3月上旬,越冬卵孵化.4月下旬,雄虫羽化,和雌虫交配后死亡.雌虫5月下旬由树干爬到树根附近疏松的泥土中产卵,越冬卵至翌年2月～3月孵化.根据草履蚧发生规律,在防治上主要抓住若虫期,分别采用人工、阻隔及药物防治,     

四川核桃优良单株选择的研究

1966年以后,在我省重点核桃产区开展优良种质资源选择工作。按坚果品质和丰产性状等选育指标,进行优树初选、复选和决选。经多性状综合评定,筛选出12株优良单株。所选择的优良单株平均树龄27年,株产坚果21.6kg,树冠投影面积产仁量0.265kg/m^2,平均单果重12.45g,厚度1.07mm,出仁率60.25%。用这批优良单株作为无性繁殖材料,是改良我省核桃遗传品质、提高核桃生产效益的重要途径之一。     

滇橄榄主要栽培品种的物候期及经济性状

对云南省滇橄榄(Phyllanthus emblica Linn.)主栽品种及其栽培面积调查、物候期观测、经济性状调查、果实主要化学成分测定分析。结果表明:滇橄榄主栽品种6个("高黎贡山"糯滇橄榄、"保山1号、2号、3号、4号"余甘子和"红珍珠"滇橄榄)栽培面积17 098 hm^2;2月中旬至3月中旬萌芽,4月上旬至5月上旬开花,果实成熟期9月中旬至次年1月中旬,1月下旬至2月上旬落叶;其平方米冠影果实产量4.2～5.4 kg/m^2,果实单果质量14.9～45.9 g、可食率82.9%～90.2%,果肉Vc含量0.412%～0.523%、粗纤维1.30%～2.05%、总糖7.2%～11.1%、总酸1.51%～1.91%、可溶性固形物9.5%～13.2%、水分84%～86.8%。根据品种特性及栽培现状,提出了品种利用策略,为其产业可持续发展提供科学依据。     

冬樱花物候及观赏期观测

云南各地冬樱花花期有一定差异,但大都集中在12月上旬至1月中旬,紫色叶呈现期为12月下旬至1月上旬.果实成熟期为3月至4月.最佳观花期为12月中旬至1月上旬,持续时间昆明为12～15 d,思茅和景谷为10～12 d.最佳观紫色叶期为12月下旬至1月上旬,昆明为7～8 d,思茅为4～5 d.最佳现果期昆明为4月上、中旬,持续10～15 d,思茅和景谷为3月下旬至4月上旬,10～12 d.由不同地区和同一地区不同年份冬樱花物候的差异,认为冬樱花属低温春化才能开花的植物.     

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.