杨树

Then, the outturn table for poplar in Jiangsu has been constructed. By experiment on the poplar stand of different site- index, it shows that the equation fits the growth of poplar merchantable volume well, which can be used to estimate the yield of poplar stand in Jiangsu.

经对不同立地条件下的杨树林分出材量的估计实验，表明该方程适合江苏省杨树生长，为进一步编制全省杨树二元材种出材率表提供了理论与实验方法。

It eventually lost to the Tulip Poplar (also called Yellow Poplar or Tulip Tree) in 1994 but still retained the title of unofficial Kentucky state tree.

"它最终败给了杨树郁金香(又称郁金香树或杨树黄色)，但仍保留了1994年授予他"非官方肯塔基州树

The paper is to research physiological differentiation and DNA polymorphism of MLP. The main result is as follows: 1.Investigating the Poplar Resistance: the difference of sensitivity is prominent.Other poplars are infected by Melampsora larici-populina in different degree, except that Populus deltoids and Populus deltoides×P.

本论文主要是对来自西北，华北，东北和西南等省的多种落叶松—杨栅锈菌进行同工酶分析以及DNA多态性研究，得出如下结论：(1)寄主抗病性调查：杨树各派树种对落叶松杨栅锈菌的感病性差异明显，除美洲黑杨和中绥12号外，所有的杨树品种都不同程度地感染了落叶松杨栅锈菌。

Section Aigeiros is the most important section of Populus, and it playes significant economy role on forest production.

黑杨派杨树是世界上栽培面积最广，经济价值最大的杨树种类，在林木生产中占有重要的经济地位。

The cytochemical localization of POD showed that the peroxidase was found in cells ofboth cultivars after inoculation. The activity of POD in resistant cultivar was higher than that innot only the uninoculated controls but also the inoculated susceptible ones and localized morewidely, such as localized in mesophyll cell wall, intercellular spaces, membranes of chloroplastand mitochondrion and vacuolar membrane. Whereas the POD in susceptible cultivar waslocalized mainly in cell walls but little in plasma membrane with a lower range and intensitythan that in resistant cultivar.

对过氧化物酶的细胞定位研究发现，无论抗病杨树还是感病杨树，接种后均发现细胞中有过氧化物酶反应产物，通过分析发现，毛白杨过氧化物酶的活性不仅明显高于未接种的对照，也明显高于接种处理后的北京杨，并且定位更广泛，在细胞壁、细胞间隙、叶绿体膜、线粒体膜及液泡膜上均有大量定位，而北京杨酶反应产物主要分布于细胞壁上，在细胞膜、核膜局部有少量定位，定位范围及强度均小于毛白杨。

The C stock in 0-60 cm soil layer was decreased by 31% after afforested for 5 years, hut increased by 47% and 41% after afforested for 10 and 15 years respectively.

与对照农田相比，5年生杨树人工林0~60cm土壤有机碳储量下降了31%，而10年和5年生杨树人工林土壤有机碳储量分别增加了47%和41%。

With methods of limited areas, root systems of plant individuals were limited in a specific range, providing definite spatial boundary and solid basis for calculation of water requirement needed by plant individuals. On the basis of calculation of amount of water requirement, areas needed by every species to ensure enough water requirement are as follows: Populus simonii is 80.3m〓, Ulmus macrocarpa is 35. 4m〓, Artemisia halodendron is 7. 0m〓, Salix gordejvii is 11. 2m〓. Prunus armeniaca is 15. 2m〓, and Caragana microphylla is 15. 6m〓. The corresponding rational density of plantation which can maintain soil water balance and can ensure plantation stability is 125 individuals/ha for Populus simonii, 285 individuals/ha for Ulmus macrocarpa, 625 individuals/ha for Prunus armeniaca, 625 individuals/ha for Caragana microphylla, 833 individuals/ha for Salix gordejvii, and 1428 individuals/ha for Artemisia halodendron, respectively.

运用有限面积法将植物根系限制在明确的边界内，为植物耗水量的计算提供了一个明确的空间边界范围和可靠的基础，探索性和尝试性地得出了近似野外真实状态下植物个体的耗水量，以此为基础计算得出小叶锦鸡儿、山杏、黄柳、差巴嘎蒿、榆树、杨树等树种的水分营养面积分别是15.6m〓、15.2m〓、11.2m〓、7.0m〓、35.4m〓和80.3m〓，与此对应的能够维持林地土壤水分平衡和林分稳定性的各树种人工林的合理密度为：杨树125株/公顷，榆树285株/公顷，杏树625株/公顷，小叶锦鸡儿625株/公顷，黄柳833株/公顷，差巴嘎蒿1428株/公顷。

In addition, we compared the codon preferences among poplar, Arabidopsis thaliana, Oryza sative, Homo sapi- ens and Escherichia coli, and poplar was found to be most similar to A.thaliana and least similar to E.coli.

将杨树的密码子使用频率与拟南芥、水稻、大肠杆菌和人等不同模式生物种比较后发现，杨树密码子的偏爱性与同为双子叶植物的拟南芥最为相似，与人和大肠杆菌之间的差异较大。

After using the forestation method of spray sowing and inserting dry seedlings, the area of fouryearnaturalregeneration poplar and willow has taken up 5 percent of controlled area, with the area of artificialspraysowing poplar and willow taking up ten percent and the area of artificialspraysowing shrub and herbage ta...

采用喷播和深松插干造林方法，4年天然更新的杨树和柳树占治理面积的5%左右，人工栽培的杨树和柳树占10%，人工喷播的灌木、牧草占10%。在沙丘上部植被覆盖度由10%～15%增加到40%～50%，丘间低地和风蚀洼平地由50%～60%增加到75%～85%。流动沙丘初步恢复为疏林草地型固定与半固定沙丘。

Poplar plantation forest development and timber processing and utilization will have very important effects on the future relationship between timber supply and demand.

杨树人工林的发展和人工林杨树木材的加工利用对我国未来木材供求关系将产生重要影响。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。