迷迭香扦插繁殖技术研究

以经种植筛选的迷迭香组培苗3-5 cm的嫩芽及7-10 cm的嫩梢作为插穗,研究了不同基质、季节和生根促进剂等因子对生根率的影响。结果表明:以珍珠岩:河沙(1:2)作基质,激素以IBA 50 mg/L 处理插穗30 min,于春季扦插有利于生根和移栽成活率的提高,插穗生根率达98％以上。     

紫金牛扦插育苗技术

按不同扦插基质、生长调节剂和木质化程度等不同因素进行紫金牛扦插生根率、插穗生根质量Q测定。结果表明,草炭∶河沙(V∶V=1∶1)扦插生根率达94.5%,是最理想的扦插基质;质量浓度为300 mg/L的IBA处理插穗的生根质量最高,生根率达到96.9%;半木质化的插穗生根率明显高于嫩枝和全木质化。     

园林树种金蒲桃扦插繁育技术研究

以园林树种金蒲桃树枝条为材料,利用扦插繁育技术,研究不同插穗类型、不同基质、不同季节、不同生根剂和浓度对生根的影响。结果表明,选择金蒲桃嫩梢和半木质化穗条作为插穗的生根率、平均根数和平均根长没有差异,但都显著高于硬枝。金蒲桃插穗在黄心土与沙壤土混合(质量比=1∶1)基质中生根率最高(84.67%),平均根数最多(6.80条),平均根长最长(7.06 cm),是金蒲桃扦插最佳基质。插穗在春季或秋季扦插时根生长情况优于夏季,春季或秋季较适宜金蒲桃穗条扦插。插穗在ABT浓度为300 mg/L或NAA浓度为300 mg/L时生根情况较好。     

丽江桂花扦插繁殖试验

在丽江市玉龙县拉市镇打鱼村开展了桂花扦插繁殖试验,用插穗木质化程度、扦插基质、激素种类3个因子3个水平进行了正交试验设计,采用了方差分析和多重比较分析,试验结果表明:插穗木质化程度、扦插基质、激素种类3个因子对桂花扦插生根率的影响大小顺序为:插穗木质化程度扦插基质激素种类。桂花扦插的生根率最佳组合为:插穗半木质化枝条、基质细腐殖土+红壤土(2∶1)、激素ABT1号生根粉200mg/L,平均生根率达到94%。     

紫花含笑扦插繁殖试验

采用L9(34)正交设计,研究不同生根促进剂种类、浓度及不同扦插基质对紫花含笑扦插生根率、生根条数的影响,结果表明:3个因素对紫花含笑扦插生根率、生根条数的影响均达到极显著水平,最佳组合为ABT1#800 mg·kg-1、基质为红壤+珍珠岩(1∶1),该组合能使紫花含笑扦插平均生根率达到87.9%、平均生根数达到9.6条。采用双因素试验研究不同插穗下切口型、不同木质化程度插穗对紫花含笑扦插生根率的影响,结果表明,2个因素对紫花含笑扦插生根率的影响均达到极显著水平,最佳组合为采用半木质化绿枝为插穗,下切口双削面,平均生根率达89.9%。综合试验结果表明,紫花含笑扦插育苗以半木质化绿枝为插穗,下切口双削面,蘸ABT1#800 mg·kg-1溶液,红壤+珍珠岩(1∶1)为基质扦插效果最好。     

美国红栌的扦插繁殖

美国红栌（Cotinus coggyaria）是一种新型的彩叶树种,具有很高的园林价值。通过使用不同浓度的生根剂一吲哚丁酸（IBA）,对美国红栌不同类型的枝条（包括半木质化枝条、完全木质化枝条、未木质化的嫩梢枝条）进行处理,测定各种插穗生根率及生根条数。结果表明：使用1500mg／L吲哚丁酸（IBA）溶液处理的美国红栌插穗生根率最高,生根条数最多;而在生根插穗中又以半木质化的插穗生根率最高,生根条数最多。     

中山杉嫩枝扦插繁育技术研究

以中山杉118和302为试材,采用L9(34)正交试验设计,分析激素浓度、基质类型、穗条的木质化程度等因素对中山杉嫩枝扦插生根率的影响,结果表明:中山杉118最佳扦插生根条件为:半木质化程度的穗条,基质为V泥炭:V珍珠岩:V园土=3∶3∶1,激素浓度为750mg·L-1。在该条件下插穗嫩枝扦插平均生根率73.27%。中山杉302最佳扦插生根条件为:半木质化程度的穗条,基质为V泥炭:V珍珠岩:V园土=3∶3∶1,激素浓度为1000mg·L-1。在该条件下,其嫩枝插穗平均生根率为50.33%。     

红叶石楠容器苗扦插试验

于夏季采用红叶石楠当年生半木质化枝条为插穗,进行了不同基质(林地表土、菜园土、细河沙)、叶片不同处理(留全叶、留半叶、留叶1/3)的容器苗扦插效果比较试验,结果表明:林地表土和菜园土消毒后作为红叶石楠的扦插基质较好,平均生根率分别达96.3%、93.0%,≥2cmⅠ级侧根数分别达3.4条、2.8条,抽梢率分别达95.3%、93.0%;细河沙的插穗生根及抽梢效果较差。插穗叶片留全叶、留半叶的扦插生根率及抽梢率较高,平均生根率分别达96.7%、94.0%,≥2cmⅠ级侧根数分别达3.5条、2.5条,抽梢率分别达97.7%、90.7%;留叶1/3的插穗生根率及抽梢率较低。     

紫金牛扦插育苗技术

按不同扦插基质、生长调节剂和木质化程度等不同因素进行紫金牛扦插生根率、插穗生根质量Q测定.结果表明,草炭:河沙(V :V=1:1)扦插生根率达94.5%,是最理想的扦插基质;质量浓度为300 mg/L的IBA处理插穗的生根质量最高,生根率达到96.9%;半木质化的插穗生根率明显高于嫩枝和全木质化.     

巴戟天扦插及林下栽培试验

选取巴戟天当年生半木质化藤蔓和2年生木质化藤蔓作插穗;插穗经50、100、150 mg·L^-1的NAA、IBA、ABT生根粉浸泡4 h后,扦插于黄心土、1份黄心土+1份河沙(等体积配比,下同)、1份黄心土+1份泥炭土+1份河沙的基质中,扦插60 d后统计生根率。以1年生扦插苗进行林下栽培试验,并连续4年调查其生长量。结果表明：以黄心土、1份黄心土+1份河沙、1份黄心土+1份泥炭土+1份河沙为基质扦插巴戟天,其扦插生根率分别为65.51%、72.62%、74.35%。以1份黄心土+1份河沙、1份黄心土+1份泥炭土+1份河沙为基质,其扦插生根率均显著高于(P<0.05)以黄心土为基质的。以不同浓度的3种植物生长调节剂处理的扦穗,其生根率比对照(清水)的均有显著提高(P<0.05)。3种植物生长调节剂中,以ABT处理的插穗生根效果最好;以IBA处理的插穗生根效果次之,但优于以NAA处理的。插穗的木质化程度对巴戟天扦插生根率有极显著影响(P<0.01),木质化插穗的扦插生根率极显著高于半木质化插穗的。以50 mg·L^-1的ABT生根...     

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.