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1.
听听绿叶的声音来自树林的最平凡的声音白桦林里的阵阵掌声红松林里的滚滚涛声听听绿听的声音来自自然的最补素的声音白天她拔动阳光的金弦夜晚她荡起明月的涟漪听听绿叶的声音来自大地的最纯粹的声音岁月对于欢乐的渴望沧桑对于坎坷的收获听听绿叶的声音来自生命的最动人的声音春风起时她的欣喜秋风起时她的羞涩听听绿叶的声音来自心灵的最圣洁的声音青春是她的音符拼搏是她的旋律听听绿叶的声音@白河  相似文献   

2.
火灾是我们人类所面临的最大的敌人.他的发生不仅毁坏了我们的家园、给人民生民的生命和财产的安全带来严重的危害.更重要的是他严重地破坏了我们所生存的自然环境的自身的平衡,直接危害到我们赖以生存的地球的安全.因此预防火灾的发生、有效的控制火灾的危害,把损失降到最低是全世界的人们极为关心的问题.文章给我们介绍了世界上经济较发达...  相似文献   

3.
酷爱绿色的民族必须擎起千年的胡杨枝才能写好你的名宇水涨水落草枯又生你对树情有独钟钻天杨般伟岸的身躯那是家园不倒的旗帜松根般有力的足趾深深扎进沙地以白桦的俊美雕刻自己的面容抡起破土镘掘出坎尔井于是,就有绿色的篱笆墙有了青藤缠绕的小屋有了葡萄般明亮的眸子有了柳枝般飘动的发辫有了风摆杨柳般清洒的舞姿不信?请到这里来作客迎接你的首先是一片清凉的绿荫植树节感怀掀开三月十二日这张日历就掀动了绿色的春潮于是,我们就亮起绿色的眼睛滴下的雨,是绿色的飞过的云,是绿色的连天上的太阳也是绿色的我们放飞一组绿色的音符寄…  相似文献   

4.
“指挥员的正确的部署来源于正确的决心,正确的决心来源于正确的判断,正确的判断来源于周到的和必要的侦察和对于各种侦察材料的联贯起来的思索。”“作几次周密的  相似文献   

5.
以怀古的心情怀念远祖的村庄试想用怎样的方式增大心脏的容量完成此生唯美的收藏把一棵树理解为成材的过程是荒唐的任何生长都有自己固执的走向把一朵花想象成爱意的装潢是荒唐的季节的表情产生于深处的独想借用一抷黑土酿制粮食的纯度借用一粒飞沙击打流浪的行程借用一叶秋愁压弯临冬的脊梁草茎与林木的风湿已深入膝踝和每一处骨节疼痛的长夜折磨事物无辜的睡床盘点库存还有多少骄傲的资本参加未来的邀请生态脆弱着已无力承载疯狂的放纵和铺张折下嫩绿的枝条就是折断春天的手指呵拘捕翠鸟的翅膀就是拘捕自由的歌唱呵开垦草原砍伐森林就是砍…  相似文献   

6.
《绿色大世界》杂志是一个呼唤绿色的信使,翻开它,便犹如置身一个绿的海洋,使我们暂时忘掉了冰冷的钢筋、竖硬的水泥,忆起了荫翳的树木遍地的花草;远离了震耳的轰鸣尖锐的汽笛,靠近了呢喃的燕语婉转的莺啼;拂去了扑鼻的烟尘车尾的废气,迎来了带叶的朝露沁人的馨香,给疲惫已久的身心一片清凉。  相似文献   

7.
地位级是反映一定树种的立地条件的好坏和林分生产力的指标。地位级的优劣是以一定年龄的林分的平均树高的差异划分的,这种划分方法主要应用于树种单纯的同龄林。在森林经营工作中,对于立地条件的调查以及地位级的划分具有十分重要的意义,因为只有对森林生长的立地质量有一个清楚的了解,才有可能采取一定的营林措施改善立地条件,提高林分的生产力;同时,由于生长在不同立地上的林  相似文献   

8.
梨树是我国的主要经济果树,要提高梨树的产量,梨树的管理至关重要。梨树的高产关键字各个季节的管理,春节的花期、夏季的病虫害、秋季的果园清理和冬季的修剪在梨树的整个生长期都需要精心的管理,“一分耕耘一分收获”。  相似文献   

9.
森林的诠释     
森林 ,人类的摇篮森林 ,煤炭的祖宗森林 ,地球的肺脏森林 ,江河的源泉森林 ,花草的乐园森林 ,云物的天堂森林 ,高等植物的博物馆森林 ,生命基因的储存库森林 ,云雾雨雪的加工厂森林 ,工农业生产的保护神森林 ,生长财富的绿色银行森林 ,没有大坝的天然水库森林 ,太阳能的储蓄器森林 ,大自然的制氧机森林 ,空气的滤清器森林 ,噪音的消声仪森林 ,防治污染的清洁工森林 ,美化环境的园艺师森林 ,改善气候的调节器森林 ,消毒治病的杀菌机森林 ,防风固沙的行家里手森林 ,水土保持的全能冠军森林 ,陆地生态系统的主体森林 ,大自然风调雨顺的物质保障…  相似文献   

10.
玩味鸟语     
春风吹过,正是鸟鸣时节。鸟,在猎人的眼里,是美味的佳肴;在孩子的眼里,是欢乐的天使;在文人的眼里,是清丽的小诗。  鸟类不仅以其优美的体态惹人喜爱,而且那悦耳动听的鸣叫声,给人们的生活增添了无限的情趣。尤其是在草木葱翠、百花怒放的春天,那真是“翻飞多好鸟,婉转弄芳辰”。  春鸟最美啭啼时。百鸟的歌声是多种多样的,杜鹃的啼声婉转回绵;金丝雀的叫声圆润甜美;画眉的鸣叫明丽豪放;百灵的歌声雍容多姿;白玉的婉啼似一条涓涓的溪水;而黄莺的低吟则像一位少女的窃窃私语……几乎每只鸟都是一位天才的音乐家,几乎一…  相似文献   

11.
In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length (SRL) of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nu-trition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches.  相似文献   

12.
全国杉木家系区域试验研究   总被引:1,自引:0,他引:1  
湖南省林科院先后于 1984年春、 1989年春两次参加全国杉木家系区域试验。方差分析表明 :提供家系的种子园之间以及种子园内家系之间各主要数量因子存在显著差异。对样本观测值进行标准化变换主成分分析 ,求出遗传综合指数 ,再聚类分析评价 :湖南靖州、江西赣南、广西柳州、贵州东南、福建三明、广东曲江种子园提供的家系生长有明显优势。  相似文献   

13.
香榧细小卷蛾Lepteucosma torreyaeWu et Chen是危害香榧的主要害虫之一,在浙江省绍兴市1 a发生2代,以老熟幼虫在枯枝落叶中做茧越冬,翌年2月中旬化蛹,3月上旬成虫羽化并产卵,3月下旬第1代幼虫孵化,5月中旬化蛹,5月下旬成虫羽化,6月上旬产卵,6月中旬第2代幼虫孵化,11月上旬开始越冬。在第2代幼虫期,使用1.8%阿维菌素乳油、5%抑太保乳油、2%阿维苏云制剂、35%吡虫啉乳油及20%杀灭菊酯乳油等5种药剂10个浓度进行喷雾防治试验,施药9 d后,防治效果均达到100%。  相似文献   

14.
对日本落叶松种子园优良家系雌雄球花数量及在树冠上的分布规律进行调查分析。结果表明:日本落叶松雄球花在树冠垂直方向上分布差异极显著,下层和中层的数量显著多于上层,所占比例为83.39%,水平方向上南面的雄球花多于其他方向;雌球花在树冠不同冠层的分布无显著差异,中、上层的雌球花数量比下层多,东、南方向多于西、北方向;雄球花多着生在2,3 a生枝上,雌球花多着生在3,4 a生枝上,1 a生枝条上无花;不同无性系间雌雄球花数量差异显著,356号无性系的雌雄球花数量均为最多。  相似文献   

15.
Beech trees occur in significantly lower latitudes in continental East Asia than in Europe and North America. They are common deciduous trees in the deciduous forests of the temperate zone in Europe, the eastern part of North America and Japan. In continental East Asia, however, they are absent in the deciduous forests of the temperate zone, but occur in the forests of mountains in the moist subtropical zone, south of 34° Northern Latitude. The lower limits of their distribution in these mountains show a significantly different pattern from the usual distribution pattern of plants and vegetation: it declines as the latitude decreases. The altitudinal belts of beech species lie higher in the northern than in the southern parts of their distribution areas in China. Based on an analysis of the climate and the phenology of these deciduous trees, we show that the prevailing monsoon conditions are the main factor affecting the distribution of the Chinese beech species.  相似文献   

16.
Transverse swelling and its anisotropy in hinoki (Chamaecyparis obtusa) in several kinds of organic liquids and in water were investigated by means the replica method. There was more cross-sectional swelling of cell walls and cell wall thickness in earlywood than in latewood. Marked swelling toward cell lumens was observed in wood swollen in liquids that had higher swelling potentials than water. This suggests that the swelling of cell walls in these liquids is much greater than the external swelling. Feret's diameters of the cell lumens were reduced by swelling in all the observed cases except in the tangential direction of earlywood, suggesting that cell walls swell to a much less extent in width than in thickness. Deformation of cell shapes caused by the tensile force from the latewood were observed in the earlywood and in the transitional region from earlywood to latewood. When swollen in water, transverse swelling anisotropy caused only by the swelling in cell wall thickness were calculated to be 1.2 for the whole region over an annual ring and 1.4 for the earlywood. These values could not account for the external swelling anisotropy of 2.1. Considering obvious deformations of cell shapes in the earlywood and in the transitional region, we conclude that the interaction between earlywood and latewood is one of the prime factors contributing to the transverse swelling anisotropy of coniferous wood.Part of this report was presented at the 48th Annual Meeting of the Japan Wood Research Society, Nagoya, April 1998  相似文献   

17.
Abstract

Seasonal behavior of vascular cambium and development of secondary xylem were studied in the 2-3-years-old branches of Azadirachta indica A. Juss. (Meliaceae) growing in moist deciduous (MDF), dry deciduous (DDF) and scrub land (SF) forests of Gujarat State. Development of xylem began with the sprouting of new leaves in January in both MDF and DDF. Xylem production culminated in July in MDF whereas it reached peak in April and July in DDF. Cambial cells ceased to divide with the maturation of leaves in November and October in MDF and DDF, respectively. Mature xylem and phloem derivatives surrounded the cambium in December in MDF and November in DDF. Radial growth in the branches of trees growing in SF was found continuous throughout the year with peak cambial activity in April, July and November. In all the three forests, maximal radial growth was encountered in July when the rains were heavy. Cambial activity and xylem development showed significant correlation with the phenology of the trees in MDF and DDF whereas cambium was found active throughout the year and no correlation was found between the cambial activity and phenology in SF.  相似文献   

18.
北京八达岭植物群落多样性特征分析   总被引:5,自引:0,他引:5  
根据34个样地的调查资料,分析了该地区森林植物群落物种多样性的特征:群落内各层物种丰富度指数的大小为草本层>灌木层>乔木层;多样性指数的大小为乔木层<灌木层和草本层。灌木层与草本层的多样性指数随林分郁闭度变化而变化,在林分郁闭度为25%的侧柏黄栌混交林中,灌木层的多样性指数和丰富度指数小于草本层;在郁闭度53%的杂木林中,灌木层和草本层的多样性指数接近;在郁闭度53%以上的各个群落内,草本层的多样性指数和丰富度指数基本上都大于灌木层。人工林中的物种多样性变化多样,明显低于天然林,林分层次单一,更新不良,缺乏灌木层和地被植物,生态系统很不稳定。  相似文献   

19.
九寨沟中华松针蚧生物学特性研究   总被引:1,自引:0,他引:1  
中华松针蚧Sonsaucoccus sinensis (Chen)在九寨沟主要危害油松,也危害其他松类。该虫1 a发生1代,主要以2龄若虫在松针上越冬;3月下旬雄若虫老熟,出壳结茧化蛹,5月上旬成虫羽化交配,6月上旬开始产卵,6月下旬若虫孵化,发育至2龄于10月下旬开始越冬。年发生动态分越冬代为害、初孵若虫为害和虫口自然消减3个时期;发生为害程度与温度、湿度、海拔、坡向等环境因子密切相关。  相似文献   

20.
In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length (SRL) of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nutrition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches.  相似文献   

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