樟子松苗木越冬防寒

樟子松苗木越冬防寒杨凤霞（塞罕坝机械林场围场县０６８４６６樟子松是一种耐寒性很强的树种，但其幼苗越冬，如措施不当也会出现冻伤，霉烂或生理干旱等灾害，造成二年留床苗缺苗断条、产苗量低，换床苗成活率低等严重后果。我们在千层板国营林场苗圃通过近１０余年的试...     

库尔勒地区造林苗木冬季越冬防寒技术

新疆库尔勒市地区冬季寒冷,气温变化剧烈,对苗木的危害很大.树木如何过冬成了当地绿化建设的-个难题.从树木发生低温危害的部位入手,提出了树木过冬防寒的主要技术及保温措施:加强肥水管理、适时进行二次冬灌、根颈培土、覆土、架风障等等.在春季来临后,防寒材料要一步步拆除,让苗木有个适应的过程.     

库尔勒地区造林苗木冬季越冬防寒技术

新疆库尔勒市地区冬季寒冷，气温变化剧烈，对苗木的危害很大。树木如何过冬成了当地绿化建设的一个难题。从树木发生低温危害的部位入手，提出了树木过冬防寒的主要技术及保温措施：加强肥水管理、适时进行二次冬灌、根颈培土、覆土、架风障等等。在春季来临后，防寒材料要一步步拆除，让苗木有个适应的过程。     

园林绿化苗木冻害原理及越冬防寒

在我国北方地区,冬季至早春,苗木容易因为遭受冻害或＂生理干旱＂而局部枝条枯干,重则会全株死亡。为确保造林绿化成果,使树木安全越冬,防止其在冬季发生冻害,在了解低温危害原因的基础上,采取必要的防寒措施,势在必行。     

东部白松1年生苗木小拱棚越冬防寒试验

东部白松是辽宁引种成功的优良树种,苗木防寒是育苗成败的关键措施。文章通过对当年播种苗木进行小拱棚和常规覆草越冬防寒对比试验,结果表明:2种防寒措施差异显著,小拱棚越冬防寒比常规覆草越冬,不仅苗木保存率提高15%,平均苗高提高3.405cm,而且方法简单,经济实用,是可行的实用技术。     

红松苗木的防寒技术

红松是珍贵的林木树种，黑龙江林区育苗比例大。红松幼苗不防寒难以越冬，土防寒效果很好，但是费工，成本高，特别是春季撤防寒土时，容易把幼苗顶芽和叶子碰掉，降低苗木质量。为寻求一种简便、经济、适用的防寒方法，我们于１９９９～２００１年在青梅实验林场苗圃，用草袋子、薄膜和土进行了防寒对比实验。１试验材料及特点试验材料采用草袋子、塑料薄膜、土壤３种。草袋子遮光而易透气，同时起到挡风的作用；薄膜防寒能起到较好的保温、保湿作用，但是，由于春秋两季气温变化大，可使薄膜内温度升高达４０～５０℃，造成苗木灼伤；土壤…     

苗木冬季防寒技术

1.加强栽培管理,增强苗木自身的抗寒能力。对苗木合理灌溉、科学施肥,多施钾肥、少施氮肥,控制苗木徒长,促进苗木生长健壮。 2.浇封冻水和返青水,控制地表温度的变化,可使地表昼夜温差相对减少,避免寒害对植物根系的危害。     

我国北方葡萄覆盖防寒越冬研究进展

中国北方冬季寒冷干燥,为了葡萄安全越冬与省工,多采用覆土防寒,保温被、秸秆和塑料膜等覆盖材料也有使用,该文综述了不同覆盖材料处理对葡萄的防寒越冬影响的研究进展,为北方葡萄覆盖防寒越冬提供参考,为进一步研发越冬防寒材料、模式等提供依据。     

The susceptibility of white spruce seedlings to overwinter injury and their post-injury field responses

Foliar and stem injury was assessed in white spruce (Picea glauca (Moench) Voss) seedlings planted in the spring and in the summer of 1992 and injured during their first overwintering on two sites in the southeastern boreal forest of British Columbia. Freeze-desiccation appears to be the main cause of the injury. Seedlot effect on the injury was significant, while planting time effect was not. Although the seedlot effect may be confounded with stock-type effect, analyses indicated increasing injury with increasing seedling height and declining ground-level diameter. Seedling vigour (height and diameter increments in the previous growing season) was also significantly related to the injury which increased with increasing vigour but the significance of this relationship varied from site to site. Condition of injured seedlings generally declined further during the post-injury growing season. This decline was greater in spring-planted than in summer-planted seedlings. Excavated root systems of container-grown seedlings showed the majority of post-planting root growth originating from the bottom-third of the nursery-container plug, deeper than 10 cm from the soil surface. This is seen as a factor potentially contributing to desiccation injury as the soil in the geographic region often remains frozen at these depths long into spring.     

浅谈苗木防寒技术

苗木防寒技术是多年来育苗工作者十分关注能技术，直接影响翌年春季苗木的质量，我们通过几年的探索和研究，摸索出一套在生产实践中比较实斥的苗木防寒技术。比较气象因子及小气候变化，土壤覆盖前后的湿度，及苗圃苗木人冬前覆土和人春后撒土，苗床方向及造成苗木受冻、受风害而死亡的现象进行分析，力争使苗木不受冻害、风害，科学静防，避免损失。     

沙棘育苗技术

为了帮助广大种植沙棘的农民朋友们了解和掌握运用沙棘生产和开发利用中的有关科学知识和技术，我们约请了有关专家编写了《沙棘科技讲座》，现由本刊分期刊登，以供在生产实践中参考。我们热忱欢迎各有关方面的沙棘生产与科技工作者指正补充，以进一步为我国的沙棘开发利用事业做好服务。     

木荷轻基质网袋容器育苗技术

通过基质配比、容器规格、缓释肥用量及容器空气切根与否4个处理对1年生木荷容器苗生长性状差异进行研究,以选择出最佳的木荷容器育苗方案。结果表明:1年生木荷容器苗受基质和空气切根的影响不显著,其基质配比中泥炭比例达到50%即可。而缓释肥用量、容器规格对木荷1年生容器苗的苗高和地径生长影响显著,木荷1年生容器苗的苗高和地径生长量随缓释肥用量的增加而增大,缓释肥量2.5 kg/m3时其苗高和地径生长量最大,容器规格为4.5 cm×12 cm时生长表现最好。综合考虑容器苗生产成本,1年生木荷容器苗最佳育苗方案为:基质中泥炭-谷壳配比为5∶5,无纺布容器规格为4.5 cm×8 cm,基质中缓释肥量为2.5 kg/m3。     

石榴育苗栽培管理技术

石榴栽培要求适宜的环境条件,主要技术包括选择优良品种、扦插育苗、适地选址建园、加强土肥水管理、合理整形修剪、花果管理与采收等。     

天女木兰繁育及大苗移植技术

天女木兰是较为理想的园林绿化树种。本文简要描述了天女木兰的形态特征及生态习性,较为详尽地介绍了繁殖、栽培、管理及大苗移栽等技术要点。     

Heat damage in tree seedlings and its prevention

Tree seedlings start to suffer stem damage or tissue death when the temperature at the soil surface reaches approximately 52°C. Seedling mortality rate accelerates as temperatures increase. Resistance to heat damage increases with size as the ability of a seedling to shade its base increase. Small newly germinated seedlings are at risk in late spring and early summer, while larger nursery-grown seedlings are at risk in mid to late summer, especially on soils with low heat capacity or conductivity, or with surfaces that are dry, dark colored or covered with organic matter. Heat damage to natural and planted seedlings usually occurs on flat or south-facing sites in regions with hot dry summers and clear skies, but can also occur in wetter regions under dry clear conditions. Shading only the basal portion of the stem appears to be as effective in preventing heat damage as shadingthe entire stem and some foliage, which can also reduce transpiration. Overhead shade and shade from live plants can reduce growth and survival.     

Comparison of three cold hardiness tests for conifer seedlings

Greenhouse-cultured, container-grown ponderosa pine (Pinus ponderosa var. scopulorum Engelm.), interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco), and Engelmann spruce (Picea engelmannii (Parry) Engelm.) were cold acclimated and deacclimated in growth chambers over 19 weeks. Cold hardiness was measured weekly by a whole-plant freeze test and by two quick tissue tests: freeze-induced electrolyte leakage of needles, and differential thermal analysis of buds. The whole-plant freeze test provided results in 7 days, and indicated differences in cold hardiness among stems, buds, and needles. Although the whole-plant freeze test could accurately measure cold hardiness, it was not precise, and it required destructive sampling. Results from freeze-induced electrolyte leakage and differential thermal analysis were available in 2 days and 1 hour, respectively. The freeze-induced electrolyte leakage test was a precise, sensitive and objective predictor of changes or differences in tissue cold hardiness. To determine actual cold hardiness, results could be calibrated to the response of the same tissue in the whole-plant freeze test. The speed and objectivity of differential thermal analysis made this test useful for rapid, general assessment of cold hardiness status, but calibration was difficult, and precision varied.     

油茶大苗移栽技术

为了提高油茶造林成活率,减少造林损失,节约管理成本,采用集中管理的4年生芽苗砧嫁接良种油茶苗进行了大苗移栽造林试验,并以1年生、2年生小苗造林试验作对照。结果表明:大苗移栽的造林成活率可达97%以上,比用1年生、2年生小苗造林的成活率几乎提高了1倍。造林试验结果说明,大苗移栽技术是提高油茶造林成活率的关键技术。     

Influence of ozone on cold acclimation in sugar maple seedlings

During summer 1994, sugar maple (Acer saccharum Marsh.) seedlings were grown in open-top chambers supplied with air containing near ambient ozone concentration (control, low O(3)) or three times the ambient ozone concentration (high O(3)). The rate of CO(2) assimilation was significantly reduced by chronic exposure to a high concentration of ozone during the summer. During fall, seedlings were removed from the open-top chambers and acclimated to cold under natural conditions. In both species during cold acclimation, the starch concentration decreased, whereas the sucrose concentration increased. There was no treatment effect on the freezing tolerance of roots, even though roots in the high-O(3) treatment accumulated higher concentrations of the cryoprotective oligosaccharides raffinose and stachyose than control roots. Cold acclimation occurred earlier and stachyose concentration of stems was higher in high-O(3)-treated seedlings than in low-O(3)-treated seedlings. Cold acclimation was associated with an earlier accumulation of ABA in the xylem sap of high-O(3)-treated seedlings compared with low-O(3)-treated seedlings.