油茶轻基质育苗试验

研究通过泡沫容器轻基质试验,筛选适合油茶Camellia oleifera苗木培育的轻基质配方。研究结果表明:除不同配方基质间根系表面积在α=0.1水平上差异显著外,苗木生长、生物量及根系性状配方基质间、不同油茶材料间在α=0.05水平上差异显著。根据生长量、生物量和根系指标进行主成分分析,将配方基质分为三类,第一类是泥炭土70%+珍珠岩30%(B1)、椰糠60%+珍珠岩30%+黄心土10%(B2)、椰糠75%+黄心土25%(B3),第二类是泥炭土50%+椰糠40%+黄心土10%(B4),第三类是纯黄心土(B5)。配方基质B2、B3,苗木生长好,适应性强;配方基质纯黄心土,苗木生长较差,适应性一般;而配方基质B1、B4,1 a生时保存率极低,苗木适应性差。在油茶轻基质材料中,椰糠是一种育苗效果较好材料。移苗半年生时,除扦插苗保存率较低为67.8%,普通油茶C. deifera、高州油茶C. drupifera、广宁红山茶C. semiserrata种子苗保存率都在80%以上,至一年时,高州油茶扦插苗和广宁红花油茶保存率仅为38.0%、45.7%,总体上看,1 a生苗木保存率偏低。轻基质材料育苗时,使用泡沫育苗容器,其孔口直径应大于7 cm,容器高大于14 cm,管理要精细,做好基质保湿管理。     

广宁红花油茶轻基质盆栽育苗试验研究

选用黄心土、椰糠、泥炭土和珍珠岩四种基质,采用混料试验的单形重心设计组配14个配方处理,进行广宁红花油茶(Camellia semiserrata)苗期轻基质盆栽试验,比较不同配方基质对其幼苗生长的影响,从而筛选出适合广宁红花油茶苗期生长的盆栽育苗轻基质配方。结果表明,不同基质处理对广宁红花油茶地上部分与地下部分的影响十分显著,各项生长指标的差异达到显著或极显著水平。在14个配方中,处理M1(60%黄心土+20%椰糠+20%泥炭土)、M2(20%黄心土+60%椰糠+20%泥炭土)、M9(20%黄心土+40%椰糠+20%泥炭土+20%珍珠岩)和M5(40%黄心土+460%椰糠+20%泥炭土)是广宁红花油茶轻基质盆栽育苗的适宜配方。对不同处理基质的理化性状分析结果表明,椰糠在减少基质容重、提高基质持水量与总孔隙度方面的作用明显大于泥炭土,是良好的轻基质材料。不同处理广宁红花油茶生长指标与基质材料含量指标的相关分析表明:对广宁红花油茶地上部分与地下部分的生长,椰糠有较明显的促进;泥炭土只对株高增长有显著促进作用;珍珠岩对各项指标的作用轻微;黄心土对各项指标有较明显的抑制作用。     

不同轻基质对杉木无性系组培苗生长的影响

以杉木(Cunninghamia lanceolate)无性系组培苗为材料,选用4种育苗基质,采用单形重心混料试验设计,探究不同轻基质种类及配比对苗木质量的影响。结果表明,基质种类和配比方式对杉木无性系组培苗保存率和苗木生长有较大影响,基质中泥炭土所占的比例应控制在20%左右,并配合珍珠岩或蛭石一起使用,椰糠可不加或少加。总根长、总根表面积、总根体积、根冠比、平均根直径等根系形态参数是评价杉木无性系轻基质容器苗质量的重要指标。利用隶属函数值对不同配方的育苗效果进行综合评价,筛选出泥炭土20%+珍珠岩40%+蛭石40%的9号配方为最佳组合,移栽6个月后苗木保存率为91.70%,苗木高/径生长明显,根系发达,苗木综合质量明显优于黄心土容器苗。     

不同轻基质对杉木无性系组培苗生长的影响*

以杉木（Cunninghamia lanceolate）无性系组培苗为材料,选用4 种育苗基质,采用单形重心 混料试验设计,探究不同轻基质种类及配比对苗木质量的影响。结果表明,基质种类和配比方式对杉木 无性系组培苗保存率和苗木生长有较大影响,基质中泥炭土所占的比例应控制在20% 左右,并配合珍珠 岩或蛭石一起使用,椰糠可不加或少加。总根长、总根表面积、总根体积、根冠比、平均根直径等根系 形态参数是评价杉木无性系轻基质容器苗质量的重要指标。利用隶属函数值对不同配方的育苗效果进行 综合评价,筛选出泥炭土20%+ 珍珠岩40%+ 蛭石40% 的9 号配方为最佳组合,移栽6 个月后苗木保存 率为91.70%,苗木高/ 径生长明显,根系发达,苗木综合质量明显优于黄心土容器苗。     

江南油杉容器育苗基质筛选

用椰糠、泥炭土、塘泥、过磷酸钙和钙镁磷肥与南方普遍用作育苗基质的黄心土进行不同体积比或质量比混合作为育苗基质,开展江南油杉容器苗育苗基质试验,以期筛选出适合南方培育江南油杉的理想育苗基质.结果表明:育苗基质对江南油杉容器苗有较显著的影响,对苗木苗期的主要生长指标苗高、地径、根粗、保存率和生物量进行综合分析,筛选出较适合南方培育江南油杉容器苗的基质配方体积比为黄心土66.7％+椰糠33.3％,其次是黄心土50％+椰糠50％和黄心土80％+塘泥20％.     

不同基质处理对洋紫荆幼苗生长的影响

文章以黄心土为基础,选用泥炭土、椰糠、蘑菇渣3种常用轻基质材料,设置不同比例组成15种基质配方,通过研究不同基质配比处理下洋紫荆Bauhinia variegata的苗高、地径、地上部分干重、地下部分干重、生物量、根冠比、根系生长,评价其育苗效果,确定培养基最优配比。结果表明:不同配方基质对容器苗的生长有显著影响,处理组Z7(黄心土:泥炭土:椰糠=2:1:1)、处理组Z14(黄心土:椰糠=1:4)、处理组Z5(黄心土:椰糠=4:1)的洋紫荆容器苗综合评价值为0.75,0.63和0.55,Z3(椰糠=1)、Z13(黄心土:泥炭土=1:4)、Z6(黄心土:蘑菇渣=4:1)的洋紫荆容器苗综合评价值为0.32,0.39和0.43。综上所述,黄心土:泥炭土:椰糠=2:1:1的基质配比是洋紫荆容器苗最为理想的轻型基质配方。     

红锥育苗基质筛选

红锥Castanopsis hystrix是我国华南地区最重要的珍贵阔叶树种之一,具有重要的经济与生态效益。随着种植规模的不断扩大,壮苗培育越来越受到重视。文章以椰糠、泥炭土、珍珠岩为基础基质,以黄心土为对照,比较16种不同配比基质配方下红锥苗木的生长性状与根系指标,结果显示:轻基质配方11(泥炭土:椰糠:珍珠岩=5:3:2),1(泥炭土:椰糠:珍珠岩=10:0:0),13(泥炭土:椰糠:珍珠岩=4:4:2)的苗高、地径、根长及细根分枝等指标明显高于以黄心土为栽培基质的苗木,且这几类基质的壮苗指数均显著高于对照黄心土(P < 0.05),说明这几类轻基质配方在提高苗木质量方面具有显著效果。     

油茶轻基质容器育苗试验

为提高油茶苗造林成活率,缩短育苗周期,降低苗木运输成本,以郴2-9号油茶无性系芽苗嫁接苗为材料,采用不同的轻基质配方进行容器育苗试验.结果表明:郴2-9号油茶无性系芽苗嫁接苗在不同的轻基质配方容器中高生长和地径生长差异极显著,用(珍珠岩30％+泥炭土70％)或(锯木屑30％+泥炭土70％)做基质时,苗木高生长平均达9....     

白木香不同轻基质配比育苗技术研究

实验选取椰糠、泥炭土和黄心土3种不同轻基质作为白木香育苗基质原材料,采用L9(34)正交试验法,进行白木香不同轻基质配比容器育苗实验研究,分别测定了白木香容器苗地径、苗高、叶绿素和氮素4个生长指标。研究结果表明:不同轻型基质配比对白木香容器苗生长影响不同,表现最优的组合是A6B6C2,即最适宜的轻基质原料配比为椰糠∶泥炭土∶黄心土=6∶6∶2。     

不同基质对印度紫檀幼苗生长的影响

在黄心土中添加椰糠、泥炭土、塘泥、过磷酸钙和钙镁磷肥进行不同体积比或质量比混合作为育苗基质,培育印度紫檀容器苗,旨在筛选出适宜的育苗基质。结果表明,育苗基质对印度紫檀容器苗苗高、地径、侧根数、侧根长、根瘤菌、生物量、叶面积和叶绿素相对含量等指标的影响非常显著。综合分析评价各项指标,筛选出较适合印度紫檀容器育苗的培育基质为黄心土70%+塘泥30%、黄心土99.5%+钙镁磷肥0.5%、黄心土50%+椰糠50%和黄心土99.75%+钙镁磷肥0.25%。     

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.     

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.     

Key Habitats in the Norwegian Production Forest: A Case Study

This study investigated the forest history, structural characteristics, the presence of fungal species suggested to indicate ecological continuity in old-growth forest, and the species composition of saproxylic beetles in 30 old forest ''woodland key habitats'' (WKHs), and compared them with production forest in the same age-class in south-eastern Norway. No statistically significant differences in forest characteristics, community of saproxylic beetles or number of red-listed beetles were found between the WKHs and the production forest, probably owing to a combination of profound long-term logging and a lack of will to delineate sufficiently large WKHs in the one area with significantly less forestry impact. The study indicates the advantage of including forest history information in WKH selection where such data exist, and the importance of restoring habitats in heavily exploited forest landscapes.