共查询到20条相似文献,搜索用时 109 毫秒
1.
《林业科技开发》2011,(4)
造林、绿化种子(元/500 g),量大可优惠5%~20%红豆杉60、柳杉28、雪松200、三角枫18、重阳木40、青冈栎20、桂花25、猴欢喜60、紫楠28、泡桐45、杜鹃40、黄山栾18、香椿20、刺槐10、枸桔15、山茶花25、落羽杉30、四照花35、黄栌30、大叶女贞10、深山含笑60、红叶乌桕35、三尖杉25、杉木20、马褂木35、鸡爪槭40、黄连木25、红椎20、香樟10、红楠30、喜树10、枫香100、灯台18、爬山虎30、樱花40、枫杨8、酸枣8、苦楝8、花榈木100、海桐40、乌桕10、常春藤20、乐昌含笑100、闽楠40、水杉100、马尾松35、观光木80、红枫80、青钱柳80、 相似文献
2.
3.
4.
5.
6.
金樱子(Rosa laevigata Michx.)别名:刺榆子、刺梨子、金罂子、山石榴、山鸡头子、糖莺子、糖罐、糖果、蜂糖罐、槟榔果、金壶瓶、糖橘子、黄茶瓶、藤勾子、螳螂果、糖刺果、灯笼果、刺橄榄、灯笼果、刺兰棵子等。根皮提制栲胶;果实入药,有利尿、补肾作用; 相似文献
7.
8.
9.
10.
11.
《Scandinavian Journal of Forest Research》2012,27(1):79-87
The operational efficiency of single-tree and group selection with a single-grip harvester was studied in uneven-aged spruce forests at high altitudes in southern Norway. Three harvest intensities of single-tree selection and two group sizes were examined in group selection. Single-tree selection included harvest intensities of 25, 45 and 65% of basal area. Group sizes for group selection were 0.063 and 0.250 ha. Normally, single-tree selection is considered less efficient than group selection or clear-cutting. In this study, because time consumption per cubic metre was primarily dependent upon average harvested tree volume, the large harvested tree size for single-tree selection allowed this treatment to be more efficient than group selection. The two blocks in this study were part of a larger design of five blocks with identical treatments under varying stand conditions. The relative operational efficiency of single-tree selection compared with group selection was greatest in stands of low stocking. Other studies have also shown that mechanical damage to the residual stand is lowest under these conditions. 相似文献
12.
Trend of within-plot selection practiced in two seedling seed orchards ofAcacia mangium in Indonesia
A trend of within-plot selection was examined by applying a retrospective selection index to the results of the selection
in two seedling seed orchards ofA. mangium at South Kalimantan in Indonesia. The orchards were established in randomized complete block design with ten replications
of four tree row plots. Within-plot selections were conducted twice with around 50% of selection intensity in those orchards:
at 22 months and at 51 months after planting, then the results were analyzed with the data on volume, stem form and bole length
measured before each selection. Bole length was found to be the highest priority trait throughout the two stages of selection
in both orchards. Growth expressed by volume was also an important criterion at the first within-plot selection, while the
priority was not obvious at the second selection. Expected gains by within-plot selection were generally small, although predicted
gains were positive on all of the three traits at each stage of selection.
The seedling seed orchards analyzed in this study were established under a technical cooperation project between JICA (Japan
International Cooperation Agency) and Ministry of Forestry in Indonesia in collaboration with Inhutani 3. 相似文献
13.
基于文献回顾与理论假设,设计了一套用于测评农户对碳汇营林技术推广过程中内在认知基础的量表体系,并根据调研数据对该量表测度效果进行了实证检验。检验最终结果显示:在碳汇营林技术推广过程中,农户关于碳汇营林技术推广的交易成本与权利损失认知、农户关于碳汇营林技术推广的社会生态与经济收益认知、农户关于碳汇营林技术推广的组织参与认知等,都将对推广过程的实现度与满意度产生显著性影响。这一结果说明,本研究所提出的影响农户对碳汇营林技术推广的认知基础测度框架大体趋于合理并可以接受,这就为更进一步进行碳汇营林技术推广相关管理制度的设计与构建,提供了一个主观数据设置方面的实证支持。 相似文献
14.
15.
16.
林木育种中的早期选择* 总被引:14,自引:0,他引:14
通过对近期国内外所开展的林木早期选择进行综合分析 ,总结了早期选择的主要途径及所取得的主要成果 ,认为对林木进行早晚期相关选择是卓有成效的 ;未来早期选择的发展方向将是常规选择与标记辅助选择相结合。同时对早期选择的开展提出了建议。 相似文献
17.
Farshad Keivan Behjou 《林业研究》2012,23(4):699-702
Time and motion studies were conducted to evaluate the impact of selective cutting type on Chainsaw productivity in Caspian forests,the selective cutting performed as single and group selection cutting in the region.The selective cutting was performed on a 42-ha tract with an average slope of 30%.The results indicate that felling time for per tree is most affected by diameter at breast height,the distance among harvested trees in single-tree selection method and diameter at breast height in group selection method.The production rate in single and group selection cutting were 21.2 m 3 h-1 and 28.4 m 3 h-1 for one person,respectively.Considering the gross and net production rate in single and group selection cutting,the unit cost was 1.11 USD m-3 and 0.88 USD m-3,respectively.The results indicate that group selection cutting can be more profitable than single-tree selection method. 相似文献
18.
19.
四川核桃优良单株选择的研究 总被引:10,自引:3,他引:7
1966年以后,在我省重点核桃产区开展优良种质资源选择工作。按坚果品质和丰产性状等选育指标,进行优树初选、复选和决选。经多性状综合评定,筛选出12株优良单株。所选择的优良单株平均树龄27年,株产坚果21.6kg,树冠投影面积产仁量0.265kg/m^2,平均单果重12.45g,厚度1.07mm,出仁率60.25%。用这批优良单株作为无性繁殖材料,是改良我省核桃遗传品质、提高核桃生产效益的重要途径之一。 相似文献
20.
介绍了标记辅助选择的研究现状、研究内容、标记辅助选择效率。阐述了林木特性对标记辅助选择的影响,标记辅助选择对林木育种的作用及2个研究实例。 相似文献