绿色能源：植物是明天

能源危机———决非杞人忧天的神话人类要生存 ,就离不开能源 ,从钻木取火到煤炭、石油时代 ,每一次能源革命都把人类社会向前推进了一大步。直到现在 ,仍有许多人陶醉于征服大自然的喜悦中 ,但人类对大自然的超常索取 ,已经改变了原有的温馨和洁净。以我国为例 ,在一次性能源消费结构中 ,煤炭占７５% ,耗煤量约为１５亿吨。煤是全程污染能源 ,除了人们看得见的烟尘污染外 ,还有二氧化硫和氮氧化物。１９８８年我国二氧化硫的排放量为１４００万吨 ,１９９５年上升到１８００万吨 ,２０００年达到２４００万吨 ,由此引起的酸雨面积达到国土…     

江苏省农村能源状况及薪炭林区划

文章深入地论述了目前江苏农村能源状况及其消费结构。认为从70年代后期到现在,农村的烧柴矛盾已有缓和。1986年全省农村生活人均年耗秸秆,薪柴量已达286公斤标准煤,合计用能为1680.62万吨标煤,占农村总能耗2809.18万吨标煤的59.83%;农村生产用能1128.5万吨,占40.17%。农村生活用能仍以薪柴,秸秆生物质能源为主,煤、电、燃油等商品能源为辅。其发展趋势是商品能源消耗和生产用能逐年上升。同时,在较好地分析了薪炭林在农村能源中的作用,地位和对现实薪材年产量、2000年薪材年产量测算的基础上,对江苏省薪炭林类型区进行了科学地划分。     

能源林与林木生物转化能源化研究进展

与化石能源比较，林木是一种可再生的清洁能源；与秸秆相比，林木能量密度高，种类丰富，一次栽种，多年受益，是实现大规模能源化的理想生物资源。文中在概述能源林应用与发展现状的基础上，重点介绍了林木生物转化能源化技术的应用和研究进展。     

瑞典全面推广绿色能源

到2020年,瑞典将完全结束对石油的依赖,成为第一个完全使用可再生能源的国家石油引发了战争,石油造成了环境污染,越来越多的国际争端因石油而起。尽管如此,各国的石油使用量还是节节攀升,石油的价格也一路猛涨。为此,各国竞相开发可再生能源,期望应对越来越严峻的石油危机。最近,瑞典官方高调宣布,瑞典将在15年内完全结束对石油等石化燃料的依赖,全面使用可再生能源。此言一出,世界各地的环保组织为之欢呼。瑞典政府专门设置了一个可持续发展部,进行环境保护方面的工作,目前的一个重要任务是指导和扶持国内可再生能源的研究和开发。可持续发…     

国际议程中的生物质能源

在过去几十年中，生物能源和其它可再生能源是关于可持续发展的若干国际宣言与承诺的主题：     

“石油植物”新秀——黄连木

随着能源消耗量的不断增加，有限的常规化能源，如石油、无然气等日趋紧缺，价格也日渐昂贵，再加上石油、煤炭和天然气等化石能源的不可再生性和环境恶化效应，迫使人类不得不重新审视和调整化石能源发展战略，于是可再生的生转能源成为人类21世纪能源研究发展的热点。目前，世界各国都对利用秸秆、粮食，垃圾等生物质能发电技术加强了研究开发力度。其击，以大豆、油茶籽、油粽、黄连木等“石油植物”为原料的生物柴油技术也将出现研究高潮，这将减少人类对石油的强烈依赖。     

发展生物质能源，中国林业在行动

今年的6月5日，是第34个“世界环境日”；6月17日，是第12个“防止荒漠化日”。多年来，我国为人类生态环境保护与防治荒漠化做了大量工作，作出了巨大贡献。尤其是2006年1月1日，中国政府正式实施了《中华人民共和国可再生能源法》，这部法律明确了今后我国将采取一系列措施，激励发展风能、太阳能、水能、生物质能、地热能、海洋能等可再生能源，以保障经济社会发展时能源的需求。这说明中国政府高度重视开发利用可再生能源，并把可再生能源开发利用作为推动经济社会发展的重大举措。 现在，这部有关我国生物质能源建设的法律已经实施数月。作为我国可再生能源建设的重要职能部门——林业部门，将有何作为？将在其中担当什么样的角色？将为我国能源建设作出什么贡献？带着这一系列问题，记者走访了国家林业局植树造林司司长、国家林业局林木生物质能源办公室主任魏殿生，请他就有关问题作了解答。下面的对话是记者根据录音整理的，现飨读者。[编者按]     

浅谈环境保护与能源利用

能源和环境是社会发展和人类生存的基础。能源的利用又以不同形式并在不同程度上影响着环境的构成和质量。本文从能源利用和环境保护的关系出发,论述了能源和环境的重要性。     

开发新能源迎接新世纪2001年全区能源生态建设思路

近年来自治区党委、政府高度重视能源生态建设，把它作为我区实施可持续发展战略和西部大开发战略中搞好生态环境保护和建设的一项重要措施来抓，全区能源生态建设在促进农村产业结构调整和农村经济发展，推动农村双文明建设方面产生了明显的效果：一是到２０００年底止，全区累计已建沼气池１０２万座，占全区农户总数的１２％（其中２０００年新建３２万座），新建沼气池连续两年占全国总数的 ３０％左右。这些沼气池每年可为广大建池农户提供优质燃料４０ ０００万立方米、高效有机肥２７３７万吨；二是全区已推广普及省柴节煤灶８０４万…     

海南研究建立以麻风树为资源的“生物能源”基地

坚持“生态立省”的海南，正在研究建立以麻风树为资源的“生物能源”基地。能源专家认为，如果充分发挥生物能源优势，海南有望成为率先进入“后石油时代”的省份。     

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.