共查询到20条相似文献,搜索用时 46 毫秒
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红皮云杉生长速度较快,且具备较好的耐寒、耐旱特性,在东北及华北地区适应性较强,属于吉林地区的主要树种,观赏价值与建筑价值较高。文章从吉林地区红皮云杉种植情况入手,分析了该地区红皮云杉苗木培育方法,提出红皮云杉造林技术要点,为该树种的繁殖利用提供参考。 相似文献
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红皮云杉短周期育苗技术 总被引:4,自引:0,他引:4
为适应林业现代化发展的需要,提高红皮云杉苗期生长速度,改变其育苗周期较长的不足,以培育优质壮苗。本文根据红球云杉生物学和生态学特性,运用塑料大棚容器育苗,系统地研究了红皮云杉育苗的系列技 相似文献
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云杉壮苗培育技术 总被引:1,自引:0,他引:1
云杉是北方各林区主要的更新造林树种 ,随着天然林保护工程及生态公益林建设工程的全面启动 ,迫切需要大量的优质苗木 ,笔者根据十几年营林工作的经验 ,从理论与实践的结合上探索了培育云杉壮苗的主要技术措施。1 云杉育苗的特性云杉属阴性树种 ,喜湿凉温润的气候及肥沃、疏松、排水良好的中性或微酸性土壤 ,其幼苗期易感病虫害 ,不耐霜冻 ,预防霜冻及防治病虫害是云杉育苗成败的关键。云杉苗期生长缓慢 ,1、2年内主要发展根系 ,3年后高生长才开始明显增加 ,一般培育 4~ 5年高生长可达 2 0 cm以上 ,因此 ,加快苗期的生长 ,缩短育苗周期就… 相似文献
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文章以花石头青海云杉母树林为例,介绍了青海云杉母树林的建设及培育技术,分析了青海云杉母树林的经济、社会、生态效益。 相似文献
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红皮云杉无性繁殖技术的研究郭志忠,张俊达,任武义,张玉媛(黑龙江省兴隆林业局)红皮云杉树姿美观,生长较快,是营造用材林和“四旁”绿化的优良树种。木材轻软,纹理通直,是建筑、航空、造纸和制造乐器的重要用材。从天然优良林分、林木种子园采种育苗,是培育良种... 相似文献
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The high accuracy of log positioning and the stability of saw blades in breakdown machinery in modern sawmills have reduced
the need to add margins for sawing variations. Oversize green sawing dimensions are still needed, but mainly to allow for
drying shrinkage. This has put a new focus on better adapting green sawing dimensions to the shrinkage behavior of wood. In
this study, a method for optimization of green sawing dimensions using stochastic simulation is presented. Normal distributions
were generated for planed dry dimensions, kerf width, and target moisture content. The minimum share of boards exceeding the
specified dry dimensions was decided, and deformations in boards from all positions in the cross section in a number of logs
were simulated. The simulated shrinkage allowance from stochastic simulations was compared to experimental results from an
industry test and to finite element results based on material data for Norway spruce. The results showed that the green width
of the sawn boards should increase when the number of boards in the center yield increases. The green thickness of boards
should be thinner for center boards and outer boards than for inner boards. 相似文献
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B. Metzler 《Forest Pathology》1997,27(1):1-11
In July and in October of 1978, 1979, 1980 five Picea abies stands in Baden-Württemberg, Germany were green-pruned up to a tree height level of c. 10 m. In 1993–94, 30 pruned trees and five control trees from each stand were harvested for investigation. The quality of pruning proved to be excellent because only few branch collar, bark injuries or too long branch stubs were detected. Based on isolations from more than 6000 wood specimens of c. 20 mm3 obtained from 175 trees, specific infection rates are given for different tree compartments. Wood decay fungi as well as important blue stain fungi were only rarely present. Tolerable discolourations were limited to the stub containing core of a few trees. Wood formed after pruning showed neither more fungal infections nor other related disadvantages compared with the respective increment from unpruned control trees. Nectria fuckeliana, proved to be the most abundant fungus in pruned trees especially in the branch stubs. Respective infection rates in and close to dry branches were compared. Bacteria could be found in the pruned branch stubs, however, they did not penetrate into the heartwood or sapwood of the stems. Both summer and autumn pruning involve only very low risk of wood deterioration. However, summer pruning shows some advantages with respect to lower infection rates by N. fuckeliana. 相似文献
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紫花苜蓿 (MedicagosativaL .) ,又叫紫苜蓿、苜蓿、苜蓿草 ,豆科苜蓿属 ,多年生宿根性草本。1 主要特点1 1 产量高 ,营养丰富紫花苜蓿产量高而稳定 ,生产成本低。紫花苜蓿为长命牧草 ,0℃以下严寒和 5 5℃以上高温仍正常生长 ,1次种植可利用 7~ 8年 ,如果管理利用得好 ,可达 1 0年以上 ,在东北寒冷地区 ,1年可割 2~ 3次 ,每公顷产鲜草 3 760 0~5 3 5 0 0kg ,开花初期割的紫花苜蓿干燥率为 2 5 %~ 3 0 % ,最高可达 3 5 % ,公顷产干草 75 0 0kg以上 ,则每千克干草的生产成本 5分钱左右。紫花苜蓿质地柔软 ,味道清香、适口性好 ,是高… 相似文献
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沙棘(HippophaerhamnoidesL.)属胡颓子科,落叶小乔木。适应能力强,繁殖容易。具有防风固沙,保持水土等生态功能,且是北方地区重要经济树种之一,具有很高的经济价值。沙棘的果实含有大量的维生素和脂肪,医药上有补肺、活血功能,用以治疗肺结核、胃溃疡等病;果汁可医治风湿症、皮肤病和癍疹;嫩叶和嫩枝可提取黑色染料;花可提炼香精;种子可提炼沙棘油,沙棘油医用价值更高,可医治外伤、冠心病、多种炎症、白血病、肝癌和胃癌等;木材边缘淡黄色,心材赤褐色,纹理细致,可做小型家具和多种工艺品。1生物学特性沙棘是喜光树种,… 相似文献