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建国60年来，内蒙古自治区林木种苗生产从无到有、从简单生产到全面建设，林木种苗事业稳定发展。特别是改革开放的三十年来，全区林木种苗事业更是突飞猛进，基本形成了具有特色的林木良种选育推广、林木种苗生产供应、林木种苗行政执法和质量监督、林木种苗社会化服务管理体系，为保障全区林业生态建设和国土绿化种苗供应奠定了坚实基础。 相似文献
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林木种质资源是国家的战略资源，保护林木种质资源的安全是维护国家长远发展的基础，建设林木种质资源库是目前最有效的林木种质资源保存方式。通过总结湖北省林木种质资源库建设、研究和应用现状，分析目前林木种质资源库建设取得的成绩和存在的问题，并为今后林木种质资源的收集保存和开发利用提出了建议，旨在为科学建设林木种质资源库提供参考。 相似文献
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为探究泉州市野生林木资源分布情况，为泉州市野生林木资源开发、利用、保护提供参考。以2020年泉州市野生林木资源为研究对象，参照第二次全国林木资源普查技术规范要求，记录相关野生林木种质资源信息，包括环境、数量、海拔等。结果表明，泉州市野生林木种质资源丰富，含118科478属1383种，被子植物在物种组成中占据绝对优势，其中双子叶植物又是被子植物的主要成分；寡种科、寡种属占60%以上，科属组成复杂，物种种类丰富；安溪县野生林木植物物种多样性较其它县区更为丰富，石狮市野生林木植物物种多样性最低，物种主要集中在海拔300—900 m区间，说明泉州市野生林木资源多数分布于较温暖的海拔区间。 相似文献
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近年来，乌兰察布盟林木种苗工作紧紧围绕国家重点生态建设工程对林木种苗的需求，以生产品种对路、质量优良、数量充足的良种壮苗为目标，以林木种苗工程建设为龙头，不断提高林木种苗的科技含量，以贯彻《中共中央、国务院关于加快林业 相似文献
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真菌病害是林木的主要生物胁迫之一，严重影响林业生态安全和经济效益。近年来随着组学技术的突破，转录组技术和代谢组技术已成功应用于林木真菌病害研究，主要包括致病和抗病关键基因的挖掘、林木防御物质的动态合成、抗病分子育种等方面，但林木如何抵御真菌病害及其两者间的互作机制仍是今后研究的热点与难点。文中通过对林木遭受真菌侵染后的转录组信息和代谢组信息进行探讨，包括类黄酮物质合成途径、植物激素信号转导、林木防御关键基因和关键代谢物、关键防御机制及功能网络等，将在理论上丰富林木响应真菌病害侵染的过程，为林木和真菌病害的互作研究奠定基础，并为林木抗性育种和化学防治提供参考；此外，基于目前转录组和代谢组在林木真菌病害防御反应方面的研究，对林木基因组研究、多组学联合研究以及病原菌组学研究等进行展望，以期为林木真菌病害研究提供新思路。 相似文献
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为探究云霄县野生林木资源分布情况，为云霄县野生林木植物资源开发、利用、保护提供参考，以云霄县野生林木植物资源为研究对象，参照第二次全国林木资源普查技术规范要求，记录相关野生林木种质资源信息，包括环境、数量、海拔等。云霄县野生林木种质资源丰富，含94科272属618种，被子植物在物种组成中占据绝对优势，其中双子叶植物占总科数91.49%；寡种科、寡种属占60%以上，科属组成复杂，物种种类丰富。白果蒲桃为濒危极小种群植物，同时作为云霄县特色资源，亟需保护。从行政区划分来看，和平乡野生林木植物物种多样性较其它乡镇更为丰富，云陵镇野生林木植物物种多样性最低。 相似文献
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种苗标签是林木种子和苗木的身份证，是全面记载种子、苗木信息的主要载体，对它的使用和管理直接关系到林木种苗的质量，加强林木种苗标签的使用管理是保障种苗质量的关健。依据《中华人民共和国种子法》、国家林业局《林木种子包装和标签管理办法》、《河北省林木种苗标签管理办法》等法律的规定，无论是生产者、经营者和使用者，都应重视种苗标签的使用和管理，种苗标签的管理者也应该按着规定认真检验，如实准确地填写，不应该只流于形式。如何加强林木种苗标签的使用管理，笔者认为应从林木种苗生产者、经营者和使用者、种苗标签管理者三方面入手，加强林木种苗标签的使用和管理。 相似文献
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林木良种是林分速生丰产、优质、抗逆性林木的基础，是林业增效、林农增收的重要因素。江西省峡江县林木良种场始建于1977年，是江西专业的林木良种基地之一。多年来，在省林业厅、省林木种苗工作总站的重视和支持下，认真贯彻“以选为主，选、引、育、繁相结合”良种工作方针，不断引进新技术，加强科学研究，实行科学管理，提高集约经营水平，为改善环境、促进国民经济发展作出贡献。 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
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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