广东阳江马占相思引种与生长研究

马占相思10a引种、种源试验表明，马占相思较同属台湾相思、大叶相思、厚荚相思生长快，且干形通直；17年种源试验以产自澳大利亚昆士兰州A5（13242）号为最优良种源；马占相思在海拔300m以下低丘、低山，土层深厚，表层疏松，排水良好的酸性土上生长良好，坡向以西南或东南坡下部为宜；由树干解析可清楚看出其生长规律。     

广东阳江马占相思引种与生长研究

马占相思 10a引种、种源试验表明 ,马占相思较同属台湾相思、大叶相思、厚荚相思生长快 ,且干形通直 ;17年种源试验以产自澳大利亚昆士兰州A5(132 4 2 )号为最优良种源 ;马占相思在海拔 30 0m以下低丘、低山 ,土层深厚 ,表层疏松 ,排水良好的酸性土上生长良好 ,坡向以西南或东南坡下部为宜 ;由树干解析可清楚看出其生长规律     

厚荚相思的引种、生长、良种繁育及利用

厚荚相思于１９８５年从澳大利亚引种，经多点引种试验表明：它可在我国热带及南亚热带沿海低海拔地区的低丘、低山、岗地及沙地，无霜冻或无严重台风处发展，它为浅根性树种；其生长与年均温密切相关，即在热带生长较南亚热带为快。在海南６年可果伐作纸浆材，每亩材积可达１０ｍ３；厚荚相思优良种源产自巴布亚。在海南临高３年始花，７年种子进入盛产期，每公顷可产种４９－１０２公斤；厚芙相思硫酸盐浆可生产高质量文化用纸。     

热带相思树引种初报

本试验共收集来自巴布亚新几内亚和澳大利亚昆士兰的8种相思树共24个种源。试验结果表明,厚荚相思表现最好,大叶相思及纹荚相思次之,卷毛相思等较差、薄荚相思抗风力最强。试验表明,巴布亚新几内亚种源优于昆士兰种源。在今后引种和选育工作中应大力开发巴布亚新几内亚种源。     

厚荚相思等树种引种试验初报

对厚荚相思、马占相思、肯氏相思进行引种试验，经过４年观测，厚荚相思生长最快，平均树高６．９ｍ，年均生长１．７３ｍ，平均胸径６．１ｃｍ，年均生长１．５３ｃｍ，马占相思次之。从耐干瘠、耐寒看，厚英相思和肯氏相思较好，马占相思较差。从干形和材质看，马占相思较好，厚荚相思和肯氏相思较差。从抗风性看，肯氏相思较强，厚荚相思和马占相思较差，厚荚相思是南亚热带地区台地、丘陵低山很有发展前途的工业原料林树种。     

滨海沙地相思树引种试验研究

在滨海沙地进行５个相思树种的引种试验，通过１０ａ观测研究认为：相思树普遍能够适应滨海风沙地的恶劣条件，生长较好；厚荚相思生长迅速，干形较通直，高生长优势明显，可望成为继木麻黄、湿地松之后，营造海防林以及低效林更新改造的又一优良树种。     

卷荚相思组织培养育苗技术的研究

卷荚相思是从澳洲新引种的树种，具有生长迅速，干形通直，木材质量好的特点，试验采用ＭＳ基本培养基，芽增殖培养基附加ＢＡ０．５ｍｇ／Ｌ和ＫＴ０．５ｍｇ／Ｌ，芽增殖率可达４倍以上，壮芽培养基用改良ＭＳ，加活性炭２ｇ／Ｌ，芽可抽长２～３ｃｍ，生根培养基为１／２，ＭＳ，附加ＩＢＡ２ｍｇ／Ｌ，生根率达８５％以上，卷荚相思组织培养为解决种源不足和快速繁殖优良无性素开辟新途径。     

闽南山地引种三种相思树生长效果及适应性评价

对闽南山地引种的 3种热带相思树的生长效果及适应性分析结果表明 :马占相思生长迅速 ,干形通直 ,9 5年生平均树高、胸径、单株材积及地上部单株生物量分别达 13 7m、19 7cm、0 2 0 6m3 和 10 7 6 0kg ,但其耐干瘠能力稍差且抗寒、抗风能力弱 ;厚荚相思生长也较为迅速且耐瘠簿、耐寒 ,但抗风能力差 ;肯氏相思生长状况远不如马占相思和厚荚相思好 ,但其耐寒且抗风能力较强。马占相思和厚荚相思可做为闽南丘陵山地短周期工业原料林树种 ,肯氏相思宜作为薪炭林和水土保持林树种。     

水土严重流失地区相思类树种选择的初步研究*

在被当地群众称之为“烂头山”的水土严重流失地区，引入原产澳大利亚的耐旱相思后，成功地改变了荒山秃岭的面貌，初步控制了水土流失。经过３ａ连续试验和观测，在１８个树种４９个种源中，初步筛选出并行相思１７０２４、１７１４１号种源；大叶相思１６３５５、１６１４７、１６４８４号种源；黄花相思１５４８１、１４９６８、１４５９０号种源；薄荚相思１６１１０、１５４７８号种源；鞘尾相思１７９０６、１７０５０号种源；丝毛相思１６６４３、１５７３２号种源；厚荚相思９１０００号种源；大花相思１４６６８号种源；巴氏相思１７７１８、１５４８０、１６１３４号种源等９个树种１９个种源，这些树种与种源适应性强，速生，生物量大，植后当年即可郁闭，枯枝落叶覆盖了林地，初步起到保持水土的作用。     

10个相思类树种的生长比较与评价

本文通过对１０个相思类树种的引种栽培试验进行总结，在生长比较与聚类分析的基础上，选出了厚荚相思，卷荚相思和马占相思３个有推广前景的速生树种，为我国热带亚热带地区增加了新的造林树种。     

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.