大叶黄杨褐斑病病原菌生物学特性的研究

大叶黄杨褐斑病Ｃｅｒｃｏｓｐｏｒａ ｄｅｓｔｒｕｃｔｉｖａ Ｒａｖ．病原菌生长最适温度为２５℃，低于５℃或高于３８℃匀不能生长；偏酸环境有利于其生长，ｐＨ４．５生长最好。分生孢子在２５℃下萌发率最高，相对湿度１００％最利于萌发，ｐＨ值适应萌发范围较广，萌发率最高为ｐＨ４．０。菌落生长和分生孢子萌发对营养要求不严格，在ＰＤＡ，ＰＭＡ，ＰＳＡ培养基上生长较好，在蒸馏水中孢子萌发率亦达９０．４％；光照条     

大叶黄杨褐斑病病原菌生物学特性的研究

大叶黄杨褐斑病ＣｅｒｃｏｓｐｏｒａｄｅｓｔｒｕｃｔｉｖａＲａｖ．病原菌生长最适温度为２５℃，低于５℃或高于３８℃均不能生长；偏酸环境有利于其生长，ｐＨ４．５生长最好。分生孢子在２５℃下萌发率最高，相对湿度１００％最利于萌发，ｐＨ值适应萌发范围较广，萌发率最高为ｐＨ４．０。菌落生长和分生孢子萌发对营养要求不严格，在ＰＤＡ、ＰＭＡ、ＰＳＡ培养基上生长较好，在蒸馏水中孢子萌发率亦达９０．４％；光照条件对其影响不大     

杉木球果炭疽病病原菌及其生物学特性的研究

１９９５～１９９６年对尤溪经营林场杉木种子园的球果病害进行研究,结果表明：病原菌Ｃｏｌｅｔｏｔｒｉｃｈｕｍｓｐ．〔有性阶段是Ｇｌｏｍｅｒｅｌａｃｉｎｇｕｌａｔａ（Ｓｔｏｎｅｍ．）Ｓｐａｕｌｄ．ｅｔ．Ｓｃｈｒｅｎｋ．〕可造成杉木球果炭疽病。病原菌生长的适宜温度范围是２２～３０℃,以２６℃为菌丝最适生长温度,２４℃为分生孢子萌发最适温度;可生长的酸碱度范围为ｐＨ５～８,以ｐＨ７为最适酸碱度;分生孢子以在水滴和１００％相对湿度中萌发率最高;菌丝在常见碳源蔗糖、常见氮源蛋白胨上生长良好。     

蒜头果种腐病病原菌生物学特性的研究

对蒜头果种腐病5种主要病原菌作温度、空气相对湿度及培养基的酸碱度对菌丝生长和分生孢子萌发影响的研究。结果表明，高温(25～35℃)有利于菌丝生长和孢子萌发；菌丝生长对空气相对湿度要求不严格，高湿(RH≥100％)明显促进分生孢子萌发；各病原菌菌丝生长和分生孢子萌发适应的pH值范围较广，以pH5～10较适宜，但以中性左右的酸碱度为最佳，具体pH值稍有差异。经方差分析可知，各病原菌菌丝生长和分生孢子萌发在最适温湿度和酸碱度条件下与其他温湿度和酸碱度条件相比存在极显著差异。     

花椒盘二孢生物学特性的研究

花椒盘二抱为花椒褐斑病的病原菌，是作者近年发现的新种。经室内培养试验，明确该病原菌菌落生长及及分生抱子萌发的适宜条件为：菌落在ＰＤＡ培养基上生长较好，温度１０～３０℃均可，２５℃最适，好气，ｐＨ４．５～５．０为宜，碳源以蔗糖为好，氮源以蛋白胖为好。分生孢子发芽温度为１０～３０℃，２０℃最适，需在水滴或相对湿度１００％下才能发芽，ｐＨ４～６为宜，不需营养，光照影响不大。由以上结果可了解该病的有关发病规律，并作为防治研究的依据。     

刺槐溃疡病病原菌的研究

刺槐溃疡病在山东沿海地区发生严重。研究结果表明主要病原菌为尖镰孢（ＦｕｓａｒｉｕｍｏｘｙｓｐｏｒｕｍＳｃｈｌｅｃｈｔ．），其次为腐皮镰孢（Ｆｕｓａｒｉｕｍｓｏｌａｎｉ（Ｍａｒｔ．）Ｓａｃｃ．）。尖镰孢的小型分生孢子头状，聚生于短的单出瓶梗上，分生孢子椭圆形至腊肠形，７．６～１５．４μｍ×２．５～３．８μｍ；大型分生孢子镰刀形至纺锤形，３～５分隔，２８．２～３８．４μｍ×４．６～５．１μｍ；厚垣孢子直径８．９～１２．８μｍ。腐皮镰孢的小型分生孢子生于伸长的分生孢子梗上，阔卵形至椭圆形，５．１～１０．２μｍ×２．５～４．８μｍ，孢子梗长３０～８０μｍ；大型分生孢子两端较钝，３～５分隔，２０．１～３３．３μｍ×２．６～５．４μｍ；厚垣孢子直径７．７～１０．２μｍ。菌落生长适温为２５～３０℃，最适温度２８℃；ｐＨ范围５～９，最适微酸至中性；碳源以蔗糖和葡萄糖最好，氮源以蛋白胨最好。     

石榴疮痂病病原菌生理学特性研究

该文对来源于危害石榴枝干部和果实部的疮痂病病原菌Dothiorella sp.菌株的生理学特性进行了系统研究。研究结果表明：两菌株的菌丝体在5～40℃范围内均可生长，最适温度为25～30℃；在pH3～11均可生长，最适酸碱度为pH4，pH6～7时生长较为迅速；在不同碳源中，多糖生长最好，其次为单糖、二糖；在不同氮源中，以牛肉膏和蛋白胨生长最好；分生孢子在多糖中萌发最好，其次为单糖、二糖；而在氮源中以硫酸铵萌发最好；分生孢子萌发的最适温度为30℃，最适湿度为100％。两菌株问没有显著差异。     

糖槭叶枯病的初步研究

人工诱发试验表明,糖槭叶枯病的病原菌为木岑叶槭叶点霉ｐｈｙｌｏｓｔｉｃｔａｎｅｇｕｎ－ｄｉｎｉｓＳａｃｃ．ｅｔＳｐｅｇ．。该菌在ＰＤＡ等四种培养基上均能很好生长。菌丝生长温度范围为１５℃～３０℃,以２５℃生长最好。在ｐＨ６时菌丝生长最好。该病菌通过气孔侵入,潜育期为１０～１８天。病菌以分生孢子无菌丝在病叶上越冬,成为翌年初侵染源。喷洒７０％甲基托布津１０００倍液和７５％百菌清８００倍液均收到较好防治效果。     

桉树溃疡病菌的生物学特性研究

经鉴定,桉树溃疡病的病原为Phoma eucalyptica Sacc.。该病原菌菌丝生长的最适温度是25～30℃,最适pH为5～7.5。病原菌分生孢子在25℃下24 h内萌发率93%,葡萄糖和蔗糖溶液对孢子的萌发有一定促进作用。病原菌对高温的耐受性较强,菌丝和分生孢子的致死温度分别为58℃和65℃。病原菌菌丝和孢子通过伤口侵入寄主体内,无伤接种不发病。     

梨树腐烂病病原菌分生孢子萌发特性的研究

梨树腐烂病病原菌为一新变种,该病原菌分生孢子萌发的温度范围为１０￣４０℃,最适温度为２５℃,在４５℃温度下恒温处理１０ｍｉｎ就失去萌发能力,分子孢子萌发的酸碱度范围ｐＨ３．０￣７．０最适为ｐＨ４．０,分生孢子萌发需要９８％以上的相对湿度,有营养的条件有利于孢子萌发,空气充足,黑暗条件下分生孢子萌发率较高。     

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.