油茶防火林带的设置及营造

油茶是我国亚热带地区重要的木本油料树种,在世界上分布不广,我国为其自然分布中心。油茶在我国的水平分布大约在北纬18°21′-34°34′．东经98°40′～121°41′,分布区跨18个省1100个县,其垂直分布海拔多在400-800m之间,但随着经纬度和地貌不同而有差异,我省皖南、大别山区及江淮丘陵都有天然分布和较长的栽培油茶历史。     

中国多孔菌属-新记录种——摩鹿加多孔菌

海南省位于我国南海的北部,地处18°10'～20°10'N,108°37'～110°03'E之间,属于季风热带气候地区[1].这一较典型的地理位置和自然气候条件,孕育了极为丰富的生物资源,是我国多孔菌种类最丰富的地区之一[2-3].     

陇县天然沙棘资源调查

1陇县概况 　　陕西省陇县位于渭北黄土高原西端,地处东径106°26′32″～107°8′11″,北纬34°35′17″～35°6′45″之间,东连千阳,南邻宝鸡,西、北与甘肃接壤.……     

沙坪坝区花木产业发展现状及对策

一、自然概况 沙坪坝区位于重庆主城区西部,地理坐标东经106°14′36″-106°31′35″,北纬29°27′13″-29°46′36″,全区幅员面积396．2平方公里,总人口74．6万人,沙坪坝区辖11个街道办事处、12个镇和1个园区。     

海南岛坝王岭自然保护区的多孔菌研究

坝王岭是我国多孔菌资源最丰富的地区之一。本文对坝王岭自然保护区的多孔菌资源及其环境作了简要论述。热带森林区的多孔菌可划分为４个生态类型,就种类和数量而言,山地雨林中的多孔菌最丰富,河谷雨林的多孔菌次之,山地苔藓林和山顶矮林中的多孔菌最少。     

中国多孔菌一新记录种——西加薄孔菌

报道了中国多孔菌一新记录种———西加薄孔菌Antrodiasitchensis(Baxter)Gilb .&Ryvarden ,该菌产自黑龙江省小兴安岭丰林自然保护区。根据中国的材料对该菌形态特征进行了详细描述 ,并与欧洲的标本进行了比较     

浅淡密云县城园林绿化

密云县位于首都北京的东北部，地处北纬40°14′—40°48′、东经116°37′—117°34′之间，北邻河北省滦平县，东接河北省承德县和兴隆县，南与北京市的平谷、顺义区相连，西与怀柔区毗邻。县城距北京东直门65公里。总面积2226．5平方公里，年均气温11℃，无霜期177天，年平均降水量650mm。域内辖18个乡镇，347     

浅析四种退耕还林模式

山西省岢岚县地处晋西北黄土高原,位于北纬38°29′～38°59′,东经111°12′～111°52′之间,地形趋势是东北高、西南低,地形复杂,沟壑纵横,起伏不平。可分为山地、丘陵、河谷三种类型。属中温带半干旱大陆性气候,其特点是冬季漫长寒冷少雪,春季温暖干燥多风,夏季炎热雨量集中,秋季短促气候凉爽。年平均气温为6．2℃。根据不同的自然条件,以及退耕还林工程中林种、树种的不同选择,结合岢岚县立地条件的差异,笔者总结了四种退耕还林模式类型,并推广于各个退耕还林工程区,取得了良好实效。     

中国多孔菌新记录种软薄孔菌

本文报道了我国多孔菌一种新记录种软薄孔菌 Antrodia gossypina,根据中国的材料对该菌形态特征进行了详细描述 ,并与欧洲的标本进行了比较研究     

卢氏：林业大县到林业强县的转变

地处豫西边陲的三门峡市卢氏县,位于东经110°35′至111°22′,北纬33°33′至34°23′之间。居黄河、长江分水岭南北两麓,横跨崤山、熊耳、伏牛三山。北邻灵宝,东连洛宁、栾川,南接西峡,西和西南部与陕西省洛南、丹凤、商南三县接壤。全县总面积3665.2平方公里,辖19个乡镇353个村民委员会,3082个居民组,总户数79,804户,总人口37.2万。卢氏县人均纯收入2362元,属国家级贫困县。     

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.