- 更多网络例句与上层林相关的网络例句 [注：此内容来源于网络，仅供参考]
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And 706—5145 yuan·hm〓 while those by interplanting Pinus massoniana with D. margaritae were found to vary from 3. 07%—12. 74% and from 514—2407 yuan·hm〓 respectively. This economic contribution of rattan planting to the whole forestland was negatively correlated with the yield and price of timber from upper trees.
将棕榈藤和上层林分相结合，对整个林地经济收益概况作出评价的研究方法在一定程度上克服了以往分析经济效益时仅以棕榈藤为研究对象的缺陷，是对藤林经济效益研究的有益补充和完善。
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From the research result mentioned above, it was concluded that the selection of excellent single shoot tissue culture seedlings was an effective approach to guarantee fast growth and high yield of rattan plantation; the application of advance planting technique, such as controlling planting time, seedling number per group and spacing was very important for the purpose of minimizing unfavorable effect of rattan planting on upper trees, increasing cane yield and improving the level of economic gain; the determination of optimal harvest regime by adjusting the first harvest time, the lower limit of stem length for cutting as well as the harvest interval offered technical support to utilize resources reasonably and sufficiently and to enhance the economic benefit dramatically.
综合分析，通过组培快繁技术选择优质组培单芽藤是保证藤林速生丰产的有效途径；根据藤种的生物学特性，选择适宜的林地和上层林分，采取调控种植时间、丛栽株数和株行距等造林措施是减少棕榈藤间种对上层树种不利影响、有效增加原藤产量和提高林地增益水平的关键措施；而通过控制初始采收龄、起采茎长和采收间隔期，确定藤林最佳采收方式是促进资源充分利用、提高藤林的经济效益的有力保障。
- 更多网络解释与上层林相关的网络解释 [注：此内容来源于网络，仅供参考]
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bark beetle：树皮甲虫
他们的分析表明最近的干旱导致区域范围内上层林(overstory tree)的迅速减少,主要原因是树皮甲虫(bark beetle)的侵袭(infestation),而这种昆虫类的暴发是因为水胁迫引起的.