苦丁茶的组织培养研究

诱导苦丁茶具节茎段芽体发生、生长与增殖的培养基,以改良ＡｎｄｅｒｓｏｎＭＳ培养基＋ＢＡ２．０ｍｇ／Ｌ＋ＮＡＡ０．１ｍｇ／Ｌ＋ＺＴ２．０ｍｇ／Ｌ＋ＧＡ３０．５ｍｇ／Ｌ较为适宜;以改良ＡｎｄｅｒｓｏｎＭＳ培养基＋ＢＡ３．０ｍｇ／Ｌ＋ＮＡＡ０．２５ｍｇ／Ｌ＋ＺＴ１．０ｍｇ／Ｌ继代培养。培养时温度为２８℃,光照度为１５００ｌｘ,光照时间为１４ｈ／ｄ;生根处理用１／４ＭＳ＋ＩＢＡ１．０ｍｇ／Ｌ培养基。     

黑荆树离体微型繁殖的研究

运用统计分析法，对黑荆树微型繁殖各个培养程序的培养基进行筛选，从而确定适合离体快速繁殖的最优培养基组分。试验结果表明，最适合不定芽培养的培养基配方为ＭＳ＋ＢＡＰ２．０ｍｇ／Ｌ＋ＮＡＡ０～０．１ｍｇ／Ｌ＋酪蛋白水解物２００ｍｇ／Ｌ＋蔗糖３％；诱导枝芽生根的培养基为ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋蔗糖２％。试验还证实固体培养基诱导生根的效果比液体培养基好。     

黑荆树茎尖培养技术的研究

以黑荆树无菌种子苗的茎类为材料，研究了用不同的细胞分裂素，生长的浓度及其配比，培养基成分的浓度，对茎尖诱导分化芽，芽的伸长及生根的影响，研究结果；培养基为ＭＳ＋６－ＢＡ６．０ｍｇ／Ｌ＋ＬＢＡ０．０１ｍｇ／Ｌ＋ＧＡ３０．１ｍｇ／Ｌ有利于促进茎尖丛生茎的形成和伸长，１／２ＭＳ＋ＮＡＡ０．６ｍｇ／Ｌ有利于诱导芽生根，试管苗移栽成活率达９０％，并在温室里生长正常。     

沙棘组织培养培养基筛选试验

沙棘组织和培养基筛选试验结果表明，适宜沙棘外植体离体的培养基为ＭＳ＋ＮＡＡ０．０３ｍｇ／Ｌ～０．０５ｍｇ／Ｌ＋ＫＴ０．３ｍｇ／Ｌ～０．５ｍｇ／Ｌ生根培养基为ＭＳ＋ＮＡＡ０．００２ｍｇ／Ｌ＋ＫＴ１．０ｍｇ／Ｌ，同时明确了沙棘离体培养的适宜外植体为春末夏初即５月末６月初当年生嫩枝上的顶端分生组织，且不同品种间的离体培养和再生能力有明显差别。     

重瓣大岩桐快速繁殖试验

对重瓣大岩桐快速繁殖研究的结果表明：试管苗微繁基本培养基为含较高质量浓度矿质营养成分的ＭＳ；增殖所需植物生长调节剂组合为ＢＡ２．０ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ，ｍ（ＢＡ）：ｍ（ＮＡＡ）＝１０：１。高生长所需植物生长调节剂组合为ＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．１ｍｇ／Ｌ，ｍ（ＢＡ）：ｍ（ＮＡＡ）＝５：１，添加果汁发现最佳增殖培养基为ＭＳ＋ＢＡ２．０ｍｇ／Ｌ＋ＮＡＡ０．２ｍｇ／Ｌ＋草莓汁２０ｍＬ／Ｌ，     

苦丁茶的离体培养与快速繁殖

用苦丁茶萌蘖芽茎段进行离体快速繁殖，外植体采用０．１％氰霉素预处理，可有效地提高消毒效果。芽增殖培养基采用ＭＳ＋６－ＢＡ１．５ｍｇ／Ｌ＋ＫＴ２．０ｍｇ／Ｌ，ｐＨ调整为５．０有效高的增殖系数，生根培养基为１／２ＭＳ＋ＩＢＡ０．５ｍｇ／Ｌ＋ＮＡＡ０．６ｍｇ／Ｌ，能有效促进小芽生根，其移栽成活率可达９０％以上。     

NAA,BA对彩色马蹄莲品种“风韵”组织培养的影响

研究了不同ＮＡＡ，ＢＡ对彩色马蹄莲品种“风韵”组织培养过程愈伤组织增殖、芽的分化和生根的影响。结果表明：ＭＳ＋ＢＡ０４ｍｇ／Ｌ＋ＮＡＡ０５ｍｇ／Ｌ培养基对愈伤组织增殖效果最好；最佳的分化和生根培养基分别为ＭＳ＋ＮＡＡ０２ｍｇ／Ｌ＋ＢＡ１０ｍｇ／Ｌ和１／２ＭＳ＋ＮＡＡ０５ｍｇ／Ｌ。     

相思杂种——莞屏1号离体快速繁殖的研究

对相思杂种——莞屏１号离体快速繁殖各个培养程序的培养基进行筛选，从而确定适合快速繁殖的最优培养基组分。试验结果表明，最适合诱导不定芽分化与增殖、不定芽伸长以及诱导生根的培养基分别为：ＭＳ＋６ＢＡ１．０ｍｇ／Ｌ＋ＫＴ１．５ｍｇ／Ｌ＋蔗糖３％、ＭＳ＋蔗糖３％、ＭＳ＋ＩＢＡ１．０ｍｇ／Ｌ＋ＮＡＡ０．５ｍｇ／Ｌ＋蔗糖２％。文中还对外植体的分段消毒法和试管苗移栽技术问题进行了探讨     

樱桃矮化砧木SD——13组培快繁技术研究

利用ＳＤ－１３樱桃矮化砧木的嫩茎梢作为外植体，进行离体培养，研究出其生长分化的基本培养其为ＭＳ，最佳分化培养基为ＭＳ＋ＢＡ０．６ｍｇ／Ｌ＋ＮＡＡ０．０５ｍｇ／Ｌ，分化率达９４％，最佳生根培养基为１／２ＭＳ＋ＮＡＡ０．０４ｍｇ／Ｌ，生根率达９２％，移栽成活率达９５％。     

柚木优树的快速繁殖

在越南胡志明市进行柚木选优和优树快速繁殖，其个植体选用优树萌芽条件扦插萌生的腋芽茎 和茎尖。结果表明，芽增殖培养基为ＭＳ附加６－ＢＡ，２．０ｍｇ／Ｌ，ＫＴ１．０ｍｇ／Ｌ和ＮＡＡ０．５ｍｇ／Ｌ，生根培养基以１／２ＭＳ附加ＩＢＡ１．０ｍｇ／Ｌ，ＬＡＡ０．５ｍｇ／Ｌ效果最好。     

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.