听听绿叶的声音

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     

经济发达国家是如何应对森林火灾的

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...     

绿色诗签(二首)

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…     

河北漳河林场洋槐林地位级曲线

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     

关注《绿色大世界》

《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。     

松干蚧的普查方法

“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     

梨树的管理技术

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”。     

以诗歌和绿色的名义

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…     

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…     

想念鸟声

灰色的天空一张欲坠的网晶莹的露珠是云霓的童话美丽的羽毛是蓝天的梦想蜂窝状的城市寻不到鸟声甚至没有一棵小树高耸的线塔和层叠的脚手架是城市撑开的大手婉啭的鸣唱已随天线锈去黑洞洞的烟囱一把把吞嚼气流中逃散的氧村子从夜晚到早晨城市里的人即使是在消化了一碟点心喝完一杯牛奶之后也觉得很累太阳是城币一饼灰黄的蛋糕月亮是城市一只朦胧的睡眼城市的窗前没有蝴蝶城市的阳台只有塑料花微风在尘埃中喘息流水于污浊里咽泣人造的假山没有栖居的绿枝幽暗的沼池难留翩然的鸟影天籁之音被从家园逐出绿树青山已浑然成梦在一个不见落叶的秋天…     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.