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本文对美国红枫林下种植油用牡丹的形态及产量相关指标进行了研究,结果表明,美国红枫套种油用牡丹对其冠径生长的影响不大;其余指标与乔木距离远近有一定的起伏,大多指标在离乔木200cm-280cm范围内有较高的水平,单株结果量低于对照50%、种子数量低于对照50%,种子的百粒重高于对照90%,单株产量和果荚角数与对照组差异不大。本试验初步结果也表明：美国红枫是一类比较适宜与油用牡丹套种的上层落叶乔木,且离乔木200cm-280cm范围内,比其他位置套种的油用牡丹的生长及产量更具优势。 相似文献
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本研究旨在定量讨论气象条件对水稻穗—茎叶的影响。主要根据水稻的生理特征和生长规律,采用动力学的方法,分营养生长期和生殖生长期建立水稻生长模型。在此基础上,结合Forcal、Matlab等数值模拟工具,探索性的讨论气温、降水和日照3个综合因素对水稻穗—茎叶的影响。【结果】？核心部分,约150字（全面、概括、精炼）【结论】？结果表明：（1）营养生长所带来的能量优势并不能完全转化为稻穗的储存优势,而生殖生长期的环境条件对水稻的产量形成更为关键;（2）不仅营养不足对稻穗物质积累存在负面作用,而且旺长对稻穗物质积累也存在一定的负面作用;（3）该模型较好地反映了气象条件对水稻生长的影响,从能量的角度定量化的模拟四川内江地区的水稻生长情况。 相似文献
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Abbas Banj Shafiei Moslem Akbarinia Gholamali Jalali Mohsen Hosseini 《Forest Ecology and Management》2010
Most of world's forests of different climates have a history of fire, but with different severities. Fire regimes for broadleaf deciduous forests have return intervals that vary from many decades (or less) to centuries (or more). Iran has a total of 1.2 million ha of temperate forest in the north, where fires burn about 300–400 ha annually. This study focused on the impact of fire on forest structure, tree species quality, and regeneration composition (specially beech) in the Chelir forest of northern Iran. The results showed that forest fires changed the structure and had different effects on tree species composition between burned and control areas. Thin barked species such as oriental beech (Fagus orientalis Lipsky) and coliseum maple (Acer cappadocicum Gled.) have been affected more than those with thick bark, like hornbeam (Carpinus betulus L.) and chestnut-leaved oak (Quercus castaneifolia C.A. Mey). The density of oriental beech regeneration in the unburned area was greater than in the burned area, while the quantity of regeneration of hornbeam, coliseum maple and velvet maple (Acer velutinum Boiss) was higher in burned area. Forest fire had a greater effect on oriental beech quality, and changed regeneration composition in the burned area. Fire prevention activities should be considered as a silvicultural treatment for preserving these valuable forests. 相似文献
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以挪威槭的成熟种子,自由人槭的顶芽、幼嫩茎段为外植体,研究了0.1%升汞不同消毒时间、不同培养条件、不同培养基对2种槭树有效获得无菌试管苗的影响.结果表明:挪威槭种子用0.1%升汞消毒8 min,在Ms+6-BA 0.5 mg/L+NAA 0.2 mg//L的培养基上,黑暗条件、温度24～26℃下,有效的获得了无菌试管苗;自由人槭以顶芽为外植体,0.1%升汞消毒6min,在MS+6-BA 0.5(0.2)mg/L+NAA 0.2 mg/L培养基上,光照3 000 5 000 lx、温度24～26℃下,同样有效的获得了无菌试管苗. 相似文献
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Poo Chow Francis S. Nakayama Brian Blahnik John A. Youngquist Terry A. Coffelt 《Industrial Crops and Products》2008,28(3):303-308
About 15 Parthenium species grow in the North American continent with Parthenium argentatum (guayule) as the only species containing harvestable amounts of the rubber latex. The predicted commercialization of the guayule plant for its hypoallergenic latex will result in a significant amount of waste fiber or bagasse biomass that can also be put to use for making wood, paper, and other chemical products, as well as in energy production. Thus, the guayule wood and bark fibers can be considered a new source of plant biomass that may be used as a direct substitute for forest-based wood fiber. However, little information is available on the chemical composition of the wood and bark tissues of guayule (P. argentatum). The objectives of this study were to determine the chemical and fiber composition of guayule and to compare it with other wood fiber sources.Three germplasm lines of mature guayule (Cal-6, AZ-101, and G7-15) and another species of Parthenium (P. tomentosum, PT), juvenile soft maple (Acer rubrum), a deciduous tree, and milkweed (Asclepias syriaca L.) that has long fibers were the plant sources. Separate wood and bark tissues were analyzed for hot water, 1% sodium hydroxide, and alcohol–toluene extracts. In addition, the lignin, holocellulose, alpha-cellulose, and pentosan contents were determined.All the chemical components in the wood fibers for the Partheniums were equal to or greater than the juvenile maple tree. Milkweed had higher alpha-cellulose and lower alcohol–toluene extract contents than both the guayule and soft maple. The guayule bark fibers had more chemical extracts than the wood fibers. The specific gravity of guayule wood was greater than the deciduous wood species. However, the fiber lengths of soft maple wood, guayule wood, and milkweed are similar. Based on the chemical composition, P. argentatum and P. tomentosum could serve as raw materials for the paper and chemical industries as well as for energy production. 相似文献
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三角枫木材材性及用途的研究 总被引：2，自引：1，他引：2
三角枫（ＡｃｅｒｂｕｅｒｇｅｒｉａｎｕｍＭｉｑ．）在安徽省分布广泛,生长于湿润肥沃的酸性土、微碱性土及中性土,中性偏耐荫,根萌蘖性强。木材物理力学性质中等偏上,干燥和加工容易,纹理略斜,结构细,适合作高级家俱、室内装饰、纺织器材,乐器零部件等。其叶、果雅致,为优美的庭园绿化树,是一种很有发展前途的绿化和用材珍贵树种。 相似文献