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51.
NaturalregenerationofmanchurianashusuallytakesplacewheretherearesuitablesoilmoistureandseedbankofsecondarymanchurianashforestintheEasternMountainousAreaofNortheastChina.Sometimes,naturalregenerationofmanchurianashcanbefoundinpureconiferousplantation.Inordertofindoutthepossibilityofintroducingnaturalregenerationofmanchurianashinpureconiferousplantation,trialsandresear-cheshavebeencarriedoutindahurianlarchp1antationbyopeningupeffectbeltinthestands.lntheend,charactersofcommunitystructureandmicr… 相似文献
52.
5年生马尾松造纸工艺林密度试验结果表明:平均树高受造林密度的影响较小,在一定密度范围内平均胸径随造林密度的增大而减小;单位面积的材积、生物量随造林密度的增大而增大;综合林分生长、生物量结构和经济效益等因素,马尾松造纸工艺林造林密度3333株/hm2较为经济合理。 相似文献
53.
红皮云杉嫩枝扦插繁殖技术的研究 总被引:9,自引:0,他引:9
本文描述了红皮云杉嫩枝扦插繁殖技术。通过试验筛选出1种适合于红皮云杉嫩枝扦插的基质(插壤),2种使生根率达98%且根系发育良好的生根剂。同时,提出了把握扦播时机,合理运用生根剂浓度及处理时间的方法和技术措施。 相似文献
54.
Kanae Ishimaru Naoko Tokuchi Naoya Osawa Koji Kawamura Hiroshi Takeda 《Journal of Forest Research》2005,10(1):27-34
Information on primary growth behavior after planting is required for mixed-plantation revegetation using broad-leaved species. To estimate primary growth, especially from the perspective of crown coverage and changing growth rates, we examined the growth and survival of four broad-leaved species that are frequently used in erosion-control plantations in Japan. The species studied were Myrica rubra Sieb. et Zucc., Alnus pendula Matsum., Quercus glauca Thunb., and Q. serrata Thunb. The survival, height, and basal diameter of planted trees were measured over a 4-year period, and crown area was calculated over a 3-year period. We found a negative relationship between relative growth rate (RGR) and survival rate, suggesting that fast growth may be fatal when resources are severely limited. The relative height growth rate (RHGR) of A. pendula was especially high during the early period of the study (1997–1999) and then drastically declined, whereas the opposite tendency was observed in Q. glauca. The results of stem allometry analyses conformed to the specific relationships between height growth and diameter growth of the four species; increases in stem thickness based on height increments were smaller in the pioneer species A. pendula. Between-species differences in coverage per planted tree (mean crown area multiplied by survival rate) were small as a result of the negative relationship between coverage area and survival rate. 相似文献
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广西松脂原料林发展现状、存在问题与对策研究 总被引:4,自引:0,他引:4
松脂产业是广西具有资源优势的产业。通过对广西松脂原料林发展的现状、存在问题的分析研究,指出广西松脂原料林的建设应以人工林定向培育和提高松脂基地建设的科技贡献率为发展方向。发展广西松脂原料林基地应从选育松树高产脂良种,开展营造高产脂原料林速生丰产综合配套技术研究,推广先进采脂技术,以最终达到提高单位面积松脂产量,降低采脂劳动强度,提高采脂劳动生产率,实现松脂产业的可持续发展。 相似文献
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The disease known as pitch canker results from infection of Pinus species by the fungus Fusarium circinatum. This fungus also causes a serious root disease of Pinus seedlings and cuttings in forestry nurseries. Pinus radiata and P. patula are especially susceptible to the pathogen, but there are no records of pitch canker on P. patula in established plantations. To date, only planting material of this tree species in nurseries or in plantations at the time of establishment have been infected by F. circinatum. Symptoms of pitch canker have recently emerged in an established P. patula plantation in South Africa and this study sought to determine whether the symptoms were caused by F. circinatum. Isolates from cankers were identified as F. circinatum using morphology and DNA-based diagnostic markers. Microsatellite markers were then used to determine the genetic diversity of a collection of 52 isolates. The entire population included 17 genotypes representing 30 alleles, with a greater number of genotypes collected from younger (three- to six-year-old) than older (12- to 19-year-old) trees. Both mating types of F. circinatum were present, but no evidence of sexual recombination was inferred from population genetic analyses. This is the first record globally of pitch canker on P. patula trees in managed plantations. It is of significant concern to South Africa, where P. patula is the most important Pinus species utilised for plantation forestry. 相似文献
60.
以黑龙江省带岭林业局落叶松人工林为试验点,采用4种不同的采集作业模式,应用层次分析法,综合考虑作业成本、作业效率、保留木损伤、土壤干扰以及木材损耗5个指标,定量计算平缓坡和陡坡条件下不同采集作业模式的综合效益.结果表明:择伐-畜力集材作业模式是该类型伐区最适宜的作业模式. 相似文献