树种

According to the study result of species selection,12 species of Eucaly-ptus and Acacia were introduced in 1993 in Yuanmou of Yunnan Province Through observing and analysing for more than 2 years and comparing the adaptability and rapidly-growing ability with Leucaena lecocephala introduced successfully before the authors found that Eucalyptus camaldulensis,A auriculiformis ,A caciamangium were the optimal afforestation species in dry-hot river valley of Yuamou This had certain significance to guide...

根据树种选择研究结果，1993年在云南元谋引种桉属和金合欢属树种12个，经两年多的初步观测分析，并与原引种成功的新银合欢比较适应性和速生性，认为赤桉、大叶相思、马占相思可作为元谋干热河谷造林的最优树种，逐步扩大栽培试验，对当地植被恢复适生树种的使用具有一定指导意义。

Based on the 20 years' investigation and study on Parakmeria yunnanensis, the phenological characteristics, seed bearing characteristics, growth and ecological characteristics of this species were made clear and introduced in this paper.

依据云南拟单性木兰近 2 0年的调查研究结果，从物候特征、树种的结实及种子特性，林木的生长特点，生态习性等方面，介绍了该树种的生物及生态学特性；并从吸收大气污染物的能力，以及在城市环境条件下的生长状况上表述了该树种在城市绿化中的作用。

The analyses result shows that tilia and mongolian oak are suitable for regeneration under the same arboreal species and other trees is suitable under different arboreal species.

对更新联结度的分析表明：紫椴和蒙古栎更适合于在本树种的树下更新，其它树种更适合于在非本树种的大树下更新。

The results indicated that the growth of 3-year-old Prunus salicina was significantly higher than that of the other species, such as 139.1% and 153.7% higher than Toona sinensis and Juglans regia in height growth, respectively. The maximum percentage of DBH more than 1.0 cm was 91.9% for P. salicina. Next were 49.5% and 48.8% for Ulmus pumila and Pteroceltis tatarinowii, respectively. The contents of total N, total P and total K ranged from 1.36% to 2.52% in the leaves of testing species. The highest content of total N and total P was found in the leaves of Catalpa bungei, while the highest content of total K was observed in P. saltcina leaves. The results indicated that P. salicina, P. tatarinowii, U. pumila had well adaptability on the Karst area both in the growth status and the improvement to the soil with the fallen leaf.

结果表明：(1)3年生冰脆李的生长量明显优于其他树种，其高生长比香椿、核桃分别大139.1%和153.7%；植株胸径大于等于1.0 cm株数的百分比以冰脆李最高达到91.9%，其次是榆树和青檀，分别是49.5%和48.8%；(2)8个树种落叶的全N、全P和全K的总含量变动为1.36%~2.52%，其中全N、全P含量以滇楸最高，全K含量以冰脆李最大；(3)从各树种落叶前后各元素含量及其转移情况看，冰脆李、青檀表现出对大部分营养元素具有较高的循环利用养分或保持养分的能力，而香椿及刺槐相对较弱。

The result shows that the resistance of tree species at the same site closely related to the number of vessel, rays' width, radium of lignified cell and wall thickness of sclereids, and the anatomical structure of the same tree species was different at different sites.

结果表明，不同树种在同一立地条件下的导管个数、射线宽度、木化细胞半径及韧皮部石细胞壁的厚度与树种的抗虫性密切相关；同一树种在不同立地条件下其内部解剖结构有所不同。

The result shows that the resistance of tree species at the same site closely related to the number of vessel, rays' width, radium of lignified cell and wall thickness of sclereids, and the anatomical structure of the same tree spec...

结果表明，不同树种在同一立地条件下的导管个数、射线宽度、木化细胞半径及韧皮部石细胞壁的厚度与树种的抗虫性密切相关；同一树种在不同立地条件下其内部解剖结构有所不同。

However remarkable impacts were observed in the plantation in terms of community physiognomy,community structure,species composition,species richness,and biomass accumulation.1 Planting trees made community structure simple.Betula alnoidis plantation had three layers including a dominant arbor layer,a complex and well developed shrub layer and a poorly developed vine layer.The arbor layer contained few species and had a single layer.The mountain rain forest had 4 layers including the dominant arbor layer,shrub layer,grass layer and vine layer.The vine layer was well developed and very rich in species composition,and the arbor layer contained as many as 38 species that could be grouped into 3 layers.2 Sequenced by the important value,main species for the plantation and the nature forest were totally different,and the plantation had one dominant species while the nature forest contained many dominant species.3 Planting trees changed the community physiognomy.

但是人工种植西南桦林对群落的季相外貌、群落的结构、物种组成、物种丰富度以及生物量等方面有较大的影响。1人工造林使得群落结构简化，西南桦人工林的层次结构有3层，以乔木层占优势，并且有种类多而发达的灌木层，同时，藤本植物欠发达，但是乔木层树种单一，明显仅有一层；山地雨林的层次结构有4层，以乔木层占优势，还有灌木层、草本层和藤本植物，藤本植物种类多，十分发达；乔木层树种丰富，可达38种，乔木层还可分为3层。2人工造林较大程度地改变了群落的物种组成，根据重要值的大小排列，人工林和天然林的主要物种组成已经完全不同；并且人工林单优树种明显，而天然林就含有较多的优势树种。3人工造林改变了群落的外貌。

Based on the importance value, the Shannon-Wienner and Simpson index of niche breadth, the Schoener's niche proportional simulation and the Levins' niche overlap of the main trees in Qiandaohu water conservation forests were calculated in the paper.

以群落样地作为资源状态，以树种的重要值作为树种对资源位计测依据，用Shannon-Wienner、Levins和Schoener的生态位计测公式，分析了千岛湖水源涵养林26个主要树种的生态位宽度、生态位相似性比例和生态重迭指数。

The compatibility of both Gvirens and B.firmus was researched. The fermentation filtrate of Gvirens , under the concentration of 70%, had not distinct inhibitory activity to B.firmus, the biomass of B.firmus would decrease with above the 70% filtrate of Gvirens, but the fermentation filtrate of B.firmus had not inhibitive role to Gvirens. 7, The cooperation control of both Gvirens and B.firm to the pine needle blight was explored:(1) Pathogen inoculation happened prior to the bio-control treatment for 7 days, however, the disease index and control effect had not distinct differences in any treatments even if combination of the two antagonists, but the susceptibility for different kind of pine were different.(2)when antagonist and pathogen were inoculated at the same time, some control effect to the pine needle blight, including certain extent cooperation control of both Gvirens and B.firm were proved, but it wasn't distinct when two antagonists used separately, and the change of the antagonist concentration had little effect to the control effect.

G.virens与B.firmus对松赤枯病的协同控制显示：(1)预先接种病菌后(7天)再进行生物防治处理，不管那种情况，感病指数和防治效果在处理间差异不明显，浓度影响无显著差异，即使是两种生防制剂联合作用也未显著提高其防效，但不同树种间的感病性有明显差异；(2)领抗菌与病原菌同时接种，对松赤枯病有一定防治效果，两菌联合有一定的协同作用，两菌分别单独施用防效差异不显著，浓度变化对防效影响不大；(3)预先接种颇抗菌能显著提高防治效果，两菌联合处理防效更优，感病树种的感病指数可降至13一15，抗病树种的感病指数可控制在3%左右；在同一浓度下B.f1'r功US、叹叮厂即s间无显著差异，在同一领抗菌下，浓度愈高，防效愈高：松，(4)三种生防接种方式的平均效果分析表明，叹F行ens最高平均防效49.5%黑 B。

For slender branch sweet vetch which is up to 40.6% only, and analysis of variance proves that sand willow shrub forest reducing close stratum effect of wind speed has obvious advantages fully too. The seventh, there are many aspects of ecological benefit of city forest in arid and semi-arid areas.

第六、根据多目标灰色关联度评价结果，适应干旱半干旱风沙区城镇庭院绿化的针叶乔木树种为：云杉、落叶松和樟子松，其关联度评价值分别达到0.7720、0.7718和0.7622；落叶阔叶乔木树种为：山桃、垂柳、垂榆，其关联度评价值分别达到0.9554、0.8631和0.8362；花灌木树种为：玫瑰、沙地柏和黄刺玫，其关联度评价值分别达到0.7916、0.7730和0.7492。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。