国家核查组核查全区农村沼气工作

9月26—29日，由国家农业部发展计划司副司长郭红宇带队的国家农村沼气调查核查组到广西核查2003—2010年农村沼气工程建设和使用情况。自治区林业厅副厅长邓建华、副巡视员肖超陪同核查。郭红宇副司长表示：“广西沼气建设在全国属于领先水平，     

高效能源型:开辟广西沼气发展的广阔空间

沼气的发展方向:从替代薪柴型转向替代液化气天然气型"十一五"期末,广西全区农村五年新增沼气用户106万个,全区沼气池入户率提高到46.4——这两个响当当的数据,充分展现了广西农村沼气建设事业的辉煌成就。今年5月28日至6月4日,由自     

技术和创新:农村沼气可持续发展的关键

抽样调查显示,广西农村户用沼气使用率呈现逐年下降的趋势。2007年全区沼气池正常使用率85%,半停半用率11%;2009年正常使用率82%,半停半用率14.3%;2010年正常使用率80.9%,半停半用率15.8%。为此,最近记者采访了广西林业科学研究院农村能源研究所所长李金怀教授。记者:您认为导致农村沼气使用率逐年下降的原因有哪些?李金怀:近年来,农村沼气的发展进入了一个低谷期,不单是     

广西获2012年中央农村沼气项目资金2亿多元

2012年8月1日，广西获2012年中央农村沼气项目资金2．0543亿元。在2亿多元项目资金中，包括户用沼气投资17660万元，用于博白、埔北等98个县8．83万户农村户用沼气池建设；养殖小区和联户沼气投资579万元，用在富川、融水等4个县建设养殖小区和联户沼气工程214处，大中型沼气工程项目资金1107万元，用在广西玉林市博白县文地镇青河村大中猪场等10个大中型沼气工程建设；乡村服务网点投资1197万元，用在宾阳、西乡塘区等62个县建设农村沼气乡村服务网点266个。     

试论桂林市沼气建设的综合效应

桂林市的农村沼气建设始于20世纪70年代，到了80年代初，恭城县将农村沼气建设作为县、乡党委政府的主要工作来抓，经过十多年的艰苦探索，逐步形成了“猪沼果”的生态农业模式。1996年桂林开始总结学习“三位一体”的恭城经验，1997年在广西全面推广。近几年，桂林市的各级党委、政府非常重视农村沼气建设，把以沼气     

林业简讯

危朝安唐仁健提出农村沼气建设新要求 2014年6月20日、7月1日，自治区党委常委、副书记危朝安，自治区党委常委、副主席唐仁建分别在林业厅报送的广西农村沼气项目建设使用情况调研报告上作出重要批示。     

科学规范推进农村沼气项目建设

2008年12月23日,自治区林业局在田阳县召开深入学习实践科学发展观快速推进新增项目暨沼气生态家园建设工作会议。会议贯彻落实党的十七届三中全会精神和党中央、国务院关于进一步扩大内需、促进经济增长的战略部署,2008年中央新增投资1000亿中安排了30亿用于农村沼气建设,其中国家安排给广西的农村沼气建设投资为16034万元。     

自主创新攻克沼气池进料难题

近年来，沼气池特别是户用沼气池建设数量大增，一些缺乏常规沼气发酵原料的农户也建上了沼气池。为了取得沼气，农村沼气用户尝试着用蚕粪、杂草、树叶、作物秸秆等（以下称“植物性沼气发酵原料”）作为沼气发酵原料投入沼气池，但人工进料较困难。为此，一些秸秆型沼气池用人工配合机械进料，但这一种较简单方便的进料办法管理成本较高，难以在户用沼气池中推广使用。为解决植物性沼气发酵原料进料难的问题，广西蒙山县农村能源办公室自主创新、研制一种简单实用、使用成本低的进料省力装置，在户用沼气池中推广使用很有实际价值。     

论发展怒江州农村沼气的可持续性

以云南怒江州农村沼气可持续发展为切入点，分析了促进农村沼气可持续发展的重要意义，结合该州当前农村沼气发展现状，探讨了沼气发展中存在的突出问题，并提出了一系列旨在促进农村沼气可持续发展的对策。     

桂林沼气富农家

在广西桂林市林业局采访,听得最多的不是造林绿化,更不是木材生产,而是全社会动员大办沼气。市林业局局长李开生提供了这样一组数字:一个8立方米的沼气池,每年产沼气400立方米,基本满足了农村一个五口之家的生活用能问题。市政府投巨资帮助漓江两岸的农户建沼气池,六年累计建池1.4万多座,沼气入户率达到80%以上,每年为农户提供沼气500万立方米,沼肥18万吨,解决了两岸大部分农户的生活用能问题,从根本上保护了漓江两岸的森林植被,保护了漓江两岸的秀美风光。以沼气和煤电代柴的农村能源结构和燃烧方式的变革,每年可节约柴草180万立方米,相当…     

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.