根瘤菌、菌根菌对厚荚相思苗期生长的影响

对厚荚相思苗期进行接种根瘤菌、菌根菌、根瘤菌＋菌根菌的比较试验,结果表明：接种菌根菌的促生效果显著。幼苗高生长、地上部分干重、地下部分干重、根瘤个数、根瘤重量平均数比对照分别提高了53．36％。73．30％,89．69％,224．01％和186．96％。接种各菌种对幼苗的促生效果排序为：菌根菌＋根瘤菌〉根瘤菌〉菌根菌〉对照。苗木根部菌根菌感染强度排序为：菌根菌〉菌根菌＋根瘤菌〉对照。     

西澳粘滑菇在尾叶桉上的菌根合成*

利用经特殊培养的西澳粘滑菇菌种，人工接种在尾叶桉幼苗根部，３５ｄ后有６０％的幼苗根部都长出１～２个子实体，经鉴定，该子实体为原接种菌。菌根感染率检查结果表明，有８０％幼苗形成菌根。生长８个月的幼苗其平均树高比未接种苗增加５２．２％，地径增加２９．４％，地上及地下部分生物量（干重）分别比对照增加２６８％及２１４．３％。西澳粘滑菇不仅在华南地区桉树上可以完成菌根合成，而且对幼树生长的增产效果十分明显，是华南地区桉树的优良菌根菌。     

泡囊丛枝状菌根对南洋杉幼苗的接种效应

利用泡囊丛枝状菌根（ＶＡＭ）菌对慢生型树种南洋杉幼苗进行人工接种，１年后的测试结果，接种ＶＡＭ处理的幼苗其菌根感染率达１００％，而对照株仅自然感染１０．３％，接种处理幼苗的生长与对照比较，平均高增加３６．５％，地径增加１６．６％，平均冠幅增加３６．７％，枝条数目中５６．７％，接种株的生物量与对照比较，地上部分平均干重增加１００．５２％，地了下部分干重则增加１５５．７６％，表明地表球囊霉９００４菌株     

ECM和VAM菌混合接种对尾叶桉生长效应的研究

本文报道混合接种外生菌根真菌彩色豆马勃和ＶＡ菌根真菌苏格兰球囊霉对尾叶桉苗斯有接种效应。根系样口检查表明接种的两个菌朱均能在尾叶桉上成功合成的相应的菌根。接种后５个月试验的苗生长量和生长量的分析结果表明,接种与未接种对照差异极显著,其中,两种混合接种方式苗木干重分别比对照增加了２４０．３％和１９４．３％;苗高生长增加了７３．８％和４１．７％;地径增加了１７．２％和１９．３％。试验苗木对菌根的依赖性     

桉树接种固氮菌效果的研究

试验表明接种固氮菌能显著提高桉树苗木的生长及苗木各器官的生物量和Ｎ含量,接种苗木高生长比对照（不接种）增加２９．８１％、叶片数增加３７．３１％、叶片干重增加３５．０１％、茎干重增加５５．５９％、根干重增加７８．９３％、总生物量干重增加５５．８９％。不同菌株的增产效果存在差异,接种催娩克氏菌的效果较接种阴沟肠杆菌的好。接种＋施Ｎ８０ｍｇ／株处理的效果优于接种＋施Ｎ３０ｍｇ／株处理的效果。接种与施Ｎ肥的分析结果表明接种催娩克氏菌的效果等于施Ｎ８０ｍｇ／株的效果。     

蓝桉和尾叶桉混合菌根研究 Ⅱ.混合菌根的接种效应

接种苗木在生长量和生物量上均表现出极其显著的生长优势,ＥＣＭ真菌蜡蘑菌单接种及其与４种ＶＡ菌根菌剂混合接种,对苗木生长的促进作用尤为显著。在接种后１６周时,与对照苗相比,蓝桉和尾叶桉接种苗木的高生长量最大增幅分别为２８．８６％（ＬＳ）和８６．６５％（ＬＧ）;两种桉树地上部分平均干质量最大增幅分别为１２９．９３％（ＬＳ）和１３３．３４％（Ｌ）,地下部分分别为１１９．９３％（ＬＦ）和１７４．８３％（Ｌ     

黑孢块菌的苗木菌根化合成效果研究

黑孢块菌菌根化幼苗是该菌在树木上完成半人工模拟栽培的基础。采用黑孢块菌的液体纯菌种1－4mL对4个树种幼苗进行接种，90d后都能形成菌根，其感染率达94．4％－100％；菌根形态主要有4种类型，以珊瑚关居多，其次为棒状及二叉状，但不同树种上其各类型所占比例各不相同，黑孢块菌不同接种量的云南松幼苗，平均高比对照增加76．67％－131．74％，而生物量则增加1.62-2.17倍，以每株接种4mL菌液的效果为佳；不同pH值的基质试验结果表明，pH值为6.5-7.0时其菌根感染率高，生物量增加明显，苗木长势也较好。     

蓝桉和尾叶桉混合菌根研究Ⅱ.混合菌根的接种效应

接种苗木在生长量和生物量上均表现出极其显著的生长优势,ECM真菌蜡蘑菌单接种及其与4种VA菌根菌剂混合接种,对苗木生长的促进作用尤为显著。在接种后16周时,与对照苗相比,蓝桉和尾叶桉接种苗木的高生长量最大增幅分别为28.86%(LS)和86.65%(LG);两种桉树地上部分平均干质量最大增幅分别为129.93%(LS)和133.34%(L),地下部分分别为119.93%(LF)和174.83%(LG)。桉树对不同菌根菌及其组合的菌根依赖性表现出很大的差异,对混合接种的真菌组合有相对高的菌根依赖性,而对土壤菌剂依赖性很小。菌根感染与苗木生物量间有显著的相关性。试验结果还证实了P素对桉苗生长的促进作用,P素水平对菌根的接种效应有一定的影响。     

VA菌稂对黎蒴的增效作用研究

用球囊霉属VA菌根菌制成的菌剂接种黎蒴实生苗，与对照相比，株高4个月以后增加52．99％。株高、地径和根部干重8个月以后分别增加75．93％、30．67％和71．75％，均达到极显著差异水平。在接种的植株根部可发现VA菌根特有的泡囊和从枝结构。试验结果表明，VA菌根菌对黎蒴的生长有显著的增效作用。     

西南桦对菌根的依赖性及其接种效应研究

为了摸清西南桦引种驯化过程中苗木菌根存在的可能性及其对菌根的依赖程度,分别对西南桦幼苗实施ＶＡ菌根和ＥＣＭ菌根的接种试验。试验结果表明：西南桦幼苗对两个类型的菌根均可受感染,对菌根均有较强的依赖性,尤以对外生菌根的依赖性较强,而对ＶＡ菌根的依赖性属中等。西南桦幼苗接种外生菌根菌后１８０ｄ平均苗高比对照增另了９２．９８￣１０６．８５％,地上干质量增另２０６．４３￣５５４．６９％,地下中２０２．８３￣     

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.