长白山桦树上一种新腐朽病害

本文报道了我国长白山林区桦树上一种新腐朽病害,其病原菌为斜生纤孔菌Ｉｎｏｎｏｔｕｓｏｂｌｉｑｕｕｓ。该病主要发生在海拔较高的成熟桦树上,主要特征是在树干上形成黑色肿瘤,造成心材白色腐朽,受害树极易风析,后期全株死亡,对病原菌的宏观,显微结构及病害的症状进行了详细描述,并与欧洲的标本进行了比较。     

山鸡椒上一种新的干基腐朽病

本文报道了我国贵州北部山鸡椒上一种新的干基腐朽病害，其病原菌是粗皮灵芝（Ganoderma tsunodae(Yasuda ex Lloyd)Trott.)。基于本研究采集的标本及日本模式产地的标本，对此病原菌进行了详细描述。该菌主要危害贵州北部的山鸡椒，造成干基白色腐朽，最后导致树林死亡。对病害的症状，造成的危害及病原菌的分布进行了讨论。     

天山西部桦树病害

本文介绍新疆天山西部林区桦树主要的叶部、枝干及立木、木材腐朽类病害种类。     

北京地区李属树木上一种新的心材腐朽病原菌

本文报道了北京地区李属树木上一种新的心材腐朽病害,其病原菌为王氏薄孔菌(Antrodia wangii Y.C.Dai&H.S.Yuan),该菌主要引起李属树木心材褐色腐朽.根据野外调查对这种新病害的症状进行了报道,并根据实地采样对这种新的病原菌进行了详细描述.对该病原菌进行了分离培养,并对培养性状进行了描述.     

中国亚热带地区阔叶树上一种新立木腐朽病

报道了我国亚热带地区阔叶树上一种新立木白色腐朽病，其病原菌为平丝硬孔菌Rigidoporus lineatus，根据中国标本对其进行了详细描述。该菌主要危害洋槐、泡酮及其它阔叶树种。对病害的症状，造成的危害及该病的分布进行了讨论。     

四川栲树心材腐朽病研究

根据野外调查，四川青城山和峨嵋山地区栲树心材腐朽病的病原菌为淡黄木层孔菌(Phellinus gilvus(Schwein:Fr.)Pat.)，造成心材白色腐朽，最终导致受害树木枯死或风折。本文对此病害的症状进行了报道，并对采集的病原菌标本材料作了详细描述．对该菌的种内分化进行了探讨。     

长白山林区鱼鳞云杉上一种新干基白腐病

这种新干基白腐病的病原菌为绒毛昂氏孔菌Ｏｎｎｉａ ｔｏｍ ｅｎｔｏｓａ。该病主要发生于成熟林分，造成干基特别是根部腐朽。被侵染树木极易风折或风倒而死亡。根据中国的材料对该病的病原菌形态特征进行了详细描述，并与北美及欧洲的标本进行了比较研究。     

中国海南台湾相思树干基腐朽病

海南省台湾相思树(Acacia confusa Merr．)干基腐朽病为中国一种新的林业病害，其病原菌为热带灵芝(Ganoderma tropicum(Jungh．)Bres．)和粗柄假芝(Amauroderma elmerianum Murrill．)本研究根据野外调查对此新病害的症状进行了报道，并根据实地采样对这两种新的病原菌进行了详细描述。     

浙江天目山两种新的阔叶树心材腐朽病

本文报道了浙江天目山自然保护区阔叶树上的两种新的心材腐朽病害,其病原菌分别为变孢绚孔菌(Laetiporus versisporus (Lloyd) Imazeki)和白蜡多年卧孔菌(Perenniporia fraxinea (Bull.:Fr) Ryvarden).根据野外调查对这两种新病害的症状进行了报道,并根据实地采样对这两种新的病原菌进行了详细描述.     

山楂根基腐朽病初报

本文报道了辽宁省沈阳市北陵公园山楂树上一种根基腐朽病，其病原菌为茶Biao子褶卧孔菌Phylloporia ribis(Schumach.Fr.)Ryvarden。该病的主要特征是在受害树的干基形成黄褐色的大型子实体，造成根基白色腐朽。受害树容易风折，后期全株死亡。文中对该病的病原菌的宏观特征及显微结构进行了详细描述。     

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。     

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.     

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.     

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.