宝华玉兰扦插繁殖技术研究

通过不同的插穗选择试验和不同处理因素对生根影响的试验，对宝华玉兰扦插繁殖技术进行研究，结果表明：2年生实生苗的树根和干基当年生萌蘖条作插穗，扦插生根率高，可达71.3％；扦插繁殖最佳的处理组合为蛭石＋IBA 200mg／L。     

黄连木嫩枝扦插育苗研究

为解决黄连木嫩枝扦插生根难的问题，１９９３～１９９５年进行了黄连木嫩枝扦插育苗试验。结果表明，５月下旬至７月上旬为嫩枝扦插适期。嫩枝插穗首先用清水浸泡２ｈ，然后再用ＮＡＡ、ＩＢＡ、ＡＢＴ等植物生长调节剂处理，窖棚内扦插生根率可达９２％以上，其中以ＩＢＡ２００×１０－６浸蘸插穗５ｓ，生根率可达９７％。     

灯台树全光照扦插繁殖技术

灯台树是一种具有较高观赏价值的绿化珍品。扦插试验结果表明：灯台树的扦插生根率较低．以在3月中旬，插穗用ABT1号600mg／kg处理，用1／2草炭土＋1／2珍珠岩作为扦插基质，采用全光照喷雾技术，扦插效果最好，生根率可达78.3％。     

浙江红山茶扦插繁殖试验

为筛选出浙江红山茶(Camellia chekiangoleosa)最佳扦插繁殖技术,采用不同激素、不同扦插时间的单因素对比试验及不同插穗类型、不同基质、不同容器等因素的正交设计进行扦插试验。结果表明,取树干中下部萌芽条,带顶芽插条生根效果最好,生根率可达91.3%;在常用的生根促进剂中,以ABT1100 mg/L处理2 h生根效果最好,生根率可达82.0%,国光牌生根粉处理效果最差,生根率仅为14.7%,低于对照;夏季扦插生根效果最好,生根率可达78.0%,冬季扦插效果最差为29.3%;扦插基质以50%的黄心土+50%细砂为基质插条生根效果最好,生根率可达78.3%。扦插试验结果显示浙江红山茶扦插生根较慢,最快插后60 d才能生根,最慢120 d才生根,可考虑采用基质加温、全光喷雾等处理进行进一步的扦插试验,提高生根速度。     

不同生根剂及基质处理对桢楠扦插生根的影响

2014—2015年开展不同浓度IBA和NAA处理、插穗带叶与否、不同基质以及不同季节对桢楠(Phoebe zhennan)的扦插繁殖影响试验研究,结果表明：用奈乙酸和吲哚丁酸生根剂处理后,桢楠平均生根率可达90%以上,带叶插穗比不带叶扦插的生根率高,用黄心土50%+河沙50%混合基质可获得较理想的生根率,季节对桢楠扦插生根率影响不大。     

美国山核桃硬枝扦插技术研究

用美国山核桃1年生实生苗休眠枝为材料,在温室内运用电热温床加热插壤进行扦插试验,采用正交试验设计,研究不同处理对美国山核桃硬枝扦插生根率的影响。结果表明:在插壤加热条件下,插条流水冲洗12 h,用500×10-6NAA浸泡6 h后扦插,美国山核桃硬枝扦插的生根率达到80.0%。通过进一步的技术改进,最高扦插生根率可达87.8%。     

桂花嫩枝扦插繁殖技术试验

2013年6月在福建邵武市苗圃对桂花进行了当年生半木质化嫩枝扦插繁殖试验。采用不同生根促进剂、不同浓度,以及不同扦插基质处理。6个月后结果表明:桂花的嫩枝扦插生根率有显著差异,生根数量及根长等生根性状未达显著差异水平;桂花嫩枝扦插较佳的处理组合是:ABT3号生根剂,质量浓度为250 mg·L-1,生根率达90.0%;桂花在不同扦插基质条件下,生根率以2号基质(黄心土70%+河沙30%(体积比))较好。     

东北红豆杉嫩枝扦插技术研究

为探讨生产上东北红豆杉嫩枝扦插的技术,进行了不同接穗、不同药剂处理对东北红豆杉嫩枝扦插生根的影响试验,结果表明:采用甘霖1号生根剂原液浸泡不带踵插穗基部5~10 s效果最好,生根率可达71.3%,以ABT1号生根粉1 000 mg·L-1溶液速蘸带踵接穗,扦插生根率达到51%。     

色木槭嫩枝扦插试验初报

利用光照喷雾装置，采用ABT生根粉处理色木槭半木质化嫩枝，在不同基质内进行色木槭嫩枝扦插试验。结果表明适宜的激素处理与选用适宜的扦插基质，可提高色木槭的扦插生根率，最高可达90％。     

榕属树种的扦插生根试验

对黄叶榕,花叶垂叶榕,垂叶榕和黄叶垂叶榕４年榕属树种进行扦插生根试验,结果表明;扦插所用的材料,处理的方法和扦插时间不同,其平均生根率也不同。这４个树种的扦插最好在秋季进行,选用经黄化处理的当年生半木质化枝条作插穗,其基部蘸生根粉后扦插,可提高生根率,缩短生根时间。     

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.