共查询到20条相似文献，搜索用时 140 毫秒
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美国黑核桃原产北美洲,是一种果材兼用、多用途的珍贵阔叶树种。１９８４年,中国林科院在河南省洛宁县长水核桃试验站进行美国黑核桃引种试验,首批引进的种子来自美国加州的基因资源中心,以魁核桃、北加州黑核桃和奇异核桃为主。在洛宁县官西村建立的黑核桃种子园,１９９０年开花结果,收获种子１０００多粒。经观测,美国黑核桃生长量、结实量和抗逆性等表现良好。因此,从１９９０年起,在原林业部等有关部门的大力支持下,中国林科院于１９９０、１９９４和１９９６年三次组织专业小组赴美国进行考察引种。目前已从美国引进黑核桃优… 相似文献
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<正> 利用现有核桃大树改接美国东部黑核桃良种,可快速建立东部黑核桃优良无性系种子园、采穗圃,解决种源短缺问题,从而加快东部黑核桃良种的推广步伐;也可改造核桃低产园,提高核桃园的产量和效益。但大树高接美国东部黑核桃技术难度大,存在成活率低等问题。为此,我们结合“黑核桃引种推广项目”的实施,开展了“核桃大树高接美国东部黑核桃技术”研究,总结了一套成功经验,经推广应用取得了良好效果,现将其技术介绍如下: 相似文献
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黑核桃引种及栽培技术 总被引：6，自引：0，他引：6
黑核桃是世界著名的果材兼用树种。我国已引进５０多个优良种源和品种,通过引种试验研究表明：黑核桃在我国具有广阔的发展前景。江西属亚热带气候,水、热条件优越,非常适宜黑核桃的生长。介绍了黑核桃的生物学特性、主要经济性状和适生环境条件,提出了黑核桃的主要栽培技术。 相似文献
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伊犁发展美国黑核桃前景广阔 总被引：2，自引：0，他引：2
美国黑核桃是一个珍贵的果材兼用树种，也是理想的农田防护林和城市绿化树种，它具有生长快，适应性强，抗旱、抗寒、抗病虫害等特点，在我国适应范围广，生长快，病虫害少，有广泛的工业用途。新疆于近几年引种栽培，以伊犁为重点，向阿克苏、昌吉、和田、喀什等地辐射发展。美国黑核桃以其木材质地优良，坚果可食，适生范围广，生长快速以及对病虫害的抗性较强等优良特性，已被广泛引入欧洲、澳大利亚及亚洲各国。我国自1984年开始引种栽培，新疆于1991年开始引种栽培。伊犁于1998年开始经过几年的中间栽培试验，证明美国黑核桃适宜在伊犁… 相似文献
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在总结云南省多年来用材树种、经济林树种、绿化树种的林木引种及遗传改良工作状况及所获成效的基础上,指出了其中存在的问题,进而提出了云南省该项综合系统工程的发展对策。 相似文献
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策勒绿洲4种杨树的生理生态学特性的研究——P—V曲线和持水力的研究 总被引：2，自引：0，他引：2
通过对策勒绿洲的４种杨树（新疆杨、箭杆杨、胡杨和灰胡杨）的Ｐ－Ｖ曲线和持水力的测定分析,得出了初步结论：人工栽培种新疆杨和箭杆杨的抗旱性能低于乡土树种胡杨和灰胡杨。 相似文献
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Both climate and land-use changes,including the introduction and spread of allochthonous species,are forecast to affect forest ecosystems.Accordingly,forests will be affected in terms of species composition as well as their soil chemical and biological characteristics.The possible changes in both tree cover and soil system might impact the amount of carbon that is stored in living plants and dead biomass and within the soil itself.Additionally,such altera-tions can have a strong impact on the detrital food web that is linked to litter decomposition.Although there are studies on the influence of plant diversity on soil physical and chemi-cal characteristics,the effects on soil biological activity and carbon storage processes remain largely unknown.The aim of this study was to investigate and compare chemical and biological variables in covariation with plant communities in an autochthonous beech forest (Fagus sylvatica L.) and a black pine plantation (Pinus nigra J.F.Arnold subsp.nigra).Our results confirmed that the two communities were con-siderably different,with the old-growth beech community having a lower number of plant species and the pine com-munity was in development as a consequence of anthropo-genic activities.These aspects of the two communities were also reflected in the soil,with the beech soil having higher nitrogen levels and a more specialized microbial community compared to the pine soil,with most extracellular enzymes(such as peroxidase and chitinase) showing lower activity in the pine soil. 相似文献
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松材线虫病 [Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle]严重威胁我国的森林资源。浙江等地每年因该病造成大量松树枯死 ,防治松材线虫病刻不容缓。当前 ,我国防治该病主要措施是清理枯死松树 ,降低媒介昆虫松墨天牛 (Monochamus alternatus Hope)密度 ,减缓病害扩散蔓延。但在风景名胜区的松林和古树名木等 ,一旦发生该病 ,仅清理死树是不够的 ,必须采取保护性措施 ,防止因病害导致大量宝贵松树枯死。在日本 ,长期以来主要措施是在松树树冠进行空中或地面喷洒杀螟松、倍硫磷、西维因等农药 ,杀灭松墨天牛成虫 ,从而防治松… 相似文献
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Gunnar Jansson Jon Kehlet Hansen Matti Haapanen Harald Kvaalen Arne Steffenrem 《Scandinavian Journal of Forest Research》2017,32(4):273-286
Plantations of genetically improved forest trees are critical for economic sustainability in forestry. This review summarizes gains in objective traits and the resulting economic impact of tree breeding programmes in Scandinavia and Finland. Genetic improvement of forest trees in these countries began in the late 1940s, when the first phenotypically superior plus-trees were selected from natural environments. The main findings from this review are that (i) tree breeding can increase volume growth in the range 10–25%, and (ii) the bare land value associated with genetically improved trees gives a better return on investment and a shorter rotation period compared to the unimproved forests. As some Nordic countries are quite dependent on the forest industry, breeding programmes that have resulted in economic gains have been beneficial for society. Growth and wood quality traits are often adversely correlated, and the weighting of traits from an economic perspective could provide an index for determining maximum profit from breeding. Tree breeding faces an array of challenges in the future, such as changes in silviculture, climate, new pests and diseases, and demand for wood-based products. 相似文献