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结果表明：采用５５年生以下母树嫩枝扦插生根率达８０～９８％；扦插苗春季移栽成活率达９７％；２年生扦插移栽苗平均高５７．８ｃｍ，平均地径０．８ｃｍ，９０％以上的苗木可用于造林。 相似文献
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在全光雾嫩枝扦插育苗试验的基础上，采用网袋状轻型基质育苗容器进行容器育苗试验，结果表明，容器扦插平均生根率可达95％以上，较普通全光雾沙床扦插对照(CK)提高5．75％，主根数、虚根数均较对照(CK)增加1．02条，5．86条，平均苗高、地径分别增加4．33cm，0．07cm；容器扦插苗用于造林，其成活率较对照(CK)增加25．0％，当年株高、地径生长量较对照(CK)增加18．70cm，0．30cm；而且容器苗便于运输，可在整个生长季节随时移栽。 相似文献
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龙脑樟树快繁育苗技术的研究与应用 总被引：3，自引：0，他引：3
研究表明，选用插穗长6—8cm、粗0．2—0．5cm的优树萌条及半木质化的嫩枝，在春、夏、秋3季扦插，在插前土壤采用0．5％KMnO4液消毒，插穗采用1000mg/kg IBA或50mg/kgABT溶液处理，扦插后覆盖遮荫网，保持棚内相对湿度85％-95％，加强肥水、苗圃田间管理等配套技术，一般25—30d长出愈合组织产生新根，60d后新根达3-5cm时即可移栽。幼苗成活率一般为80％-85％，最高达90％以上。该技术扦插育苗，不仅成活率高，幼苗生长整齐，成本低，经济适用，操作简单;而且后代个体遗传性状稳定，为龙脑樟树快速育苗开辟了新途径。 相似文献
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以引进竹种Guadua amplexifolia为对象，进行了种苗林竹丛结构调控、全年连续育苗和主枝、次生枝扦插育苗试验，结果表明：种苗林竹丛结构调控对提高新竹质量有显著作用，处理较对照新竹径级增大51．5％，立竹全高增加30．9％；全年3次移栽育苗成活率均达87％以上，其中以5月份移栽效果好，成竹率达45．7％；1年生、2年生立竹主枝、次生枝扦插成活率68％以上，各处理生根时间无显著差异，平均为47d，综合扦插成活率、出笋成竹数、新竹地径等，以2年生立竹主枝扦插效果最佳。 相似文献
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为加速刺槐的良种化进程,用细根段刺槐根系和硬枝扦插进行育苗技术研究,提高良种繁殖率。用粗0．5 -0．8 cm的根段进行钵插育苗一般成活率可达85％以上,当年平均苗高和地径达2．5 m和2 cm以上,苗木出圃率达90％以上;利用ABT生根粉100 mg／kg进行硬枝扦插处理24 h效果最佳,扦插成活率、地径和苗高与对照相比分别高71．6％、28．9％和28．6％。 相似文献
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以顺昌县次生种源翅荚木种子为繁育材料,探讨不同基质配比、热水浸种催芽、移栽时期、施肥浓度对翅荚木秋季轻基质容器育苗的影响,并对比分析春季大田与秋季基质容器育苗的苗木生长及造林效果.结果表明,翅荚木秋季容器育苗比春季大田育苗缩短育苗期,减少育苗和造林成本,提高造林成效.以泥炭：椰康：珍珠岩配比为4：2：1的基质、80℃热水浸种催芽、种子露白点播及采用1％浓度复合肥追肥,育苗效果最好,当年平均苗高31.23cm,平均地径0.25cm,苗木出圃率90.0％,次年即可上山造林,成活率达98.0％. 相似文献
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白榆的育苗和造林大多采用播种方法,近年来,我圃采取扦插方法育苗、造林,成活率可达80—90％,且苗木生长较快。据1980年11月对当年生扦插苗和播种苗的生长调查,扦插苗平均高1.05米,平均地径0.85厘米;播种苗平均高0.87米,平均地径0.64厘米。扦插后能保持河南自榆(母树)干形直、抗性强等优良性状。一、种条的选择、采集和处理 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
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. 相似文献
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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。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):131-138
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. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):472-479
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. 相似文献
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Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
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. 相似文献
20.
A. Rigueiro-Rodríguez M. R. Mosquera-Losada E. Gatica-Trabanini 《Agroforestry Systems》2000,48(3):245-256
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. 相似文献