深山含笑引种苗期试验初报

育苗试验表明,原分布在中亚热带的深山含笑基本能适应北亚热带南京地区的气候,正常生长发育。其种子发芽出土、形成幼苗需要较高积温,在塑料薄膜棚内,约需４０ｄ。苗期生长呈单峰“＾”字形,４～６个月生长缓慢,生长量占全年１４．４％;７～９月速生,生长量占全年８１．６％;８月生长量呈现峰值,占全年３９．９％;１０～１１月生长趋于停滞．１ａ生苗高１１．５～３９．０ｃｍ,平均高２３．４ｃｍ;２ａ生苗高６５～１０     

马尾松扦插苗生长规律的初步研究

对马尾松无性系及家系扦插苗的观测研究结果表明：水培根系生长良好,侧根多且壮,须根发达;春扦１年生无性系扦插苗的主梢生长量只出现一个峰期（３￣４月）,下半年生长速率占全年生长速率的８５．９％,不同无性扦插苗生长速率的快慢有差异;高产脂家春插成活率比秋插高,在３０￣９５％之间,苗高和地径生长为２１．１ｃｍ和０．４ｃｍ,分别是秋播地的２．１１倍和１．２９倍。     

Ⅰ—45杨生长规律的初步观察

本文对Ⅰ－４５杨的苗期、幼林物候及生长情况进行了观察。在长春、辉南Ⅰ－４５杨能够完成正常的生育周期，顶芽形成期在８月末、９月实，较大青杨提前３－４天时间。苗期高生长集中在６－７月份，出现两个生长高峰期，日平均生长量可达４ｃｍ。幼林第４年生长开始加快，胸径最大年生长量为３．１ｃｍ，年生长主要在６月下旬至８月中旬，各旬生长量基本一致，平均为０．３ｃｍ。通过对Ⅰ－４５杨生长规律的观察，可为林木速生丰产、     

高效率低成本的毛白杨繁育技术研究

用苗木侧根短根穗扦插育苗，是繁殖毛白杨的一种好方法，成活率可达９５％，且苗木质量好。根穗粗度与长度对育苗成活率影响很大。根穗粗０．６ｃｍ以上，长１０ｃｍ以上可获得得较高成活率。从１年生苗上剪１－４条侧根，保留侧根基部２ｃｍ，不会影响造林成活率与幼树生长。     

银杏嫩枝土钵扦插育苗试验初报

利用银杏嫩枝进行土钵扦插育苗,其扦插成活率（９２２％）和移栽成活率（９８２％）,比常规嫩枝扦插分别提高１６２％,１１５％。且移栽后１ａ生高生长量（５０２ｃｍ）和粗生长量（０２９６ｃｍ）,比常规的生长量分别提高１４６％,９６％。因而,经济效益显著。     

杉木分级造林试验初报

经对杉木不同苗木级别的造林成活率、保存率、生长量及苗木在一年中的生长规律进行试验研究。结果表明：Ⅰ级苗成活率为７８·８％，保存率为９７．７２％，Ⅱ级苗成活率为８６．５％，保存率为９４．８％，Ⅲ级苗成活率为９０．Ｏ％，保存率为９０．１１％；Ⅰ级苗平均高生长量为１５２．６厘米，Ⅱ级苗平均高生长量为１２６．９厘米，Ⅲ级苗平均高生长量为８９．４厘米；苗木在一年中出现二次高生长高峰，分别出现在７月和１０月，其中７月份生长量占全年总生长量的２９．５５％；地径在一年中有三次生长高峰，分别出现于３、５、９月份，其中５月份生长量占全年总生长量的２０．０８％。     

樟子松苗移植密度试验

樟子松１年生苗采用２０×２０ｃｍ、２０×１０ｃｍ、２０×７５ｃｍ、２０×５０ｃｍ、２０×４０ｃｍ、２０×３３ｃｍ６种移植密度试验结果表明，苗木高生长差异不明显，地径差异达到了１％的显著水平。苗木径高比、单株生物量随着移植密度的减小而增大。一级苗百分率随密度的增大而减小，经济效益随密度的增大而上升，最大密度与最小密度的单位产值相差４倍以上。从综合质量指标和经济效益两方面考虑，以２０×４０ｃｍ和２０×５０ｃｍ两种移植密度最佳。     

I─45杨生长规律的初步观察

本文对Ｉ—４５杨的苗期、幼林物候及生长情况进行了观察。在长春、辉南Ｉ—４５杨能够完成正常的生育周期，顶芽形成期在８月末、９月初，较大青杨提前３～４天时间。苗期高生长集中在６～７月份，出现两个生长高峰期，日平均生长量可达４ｃｍ。幼林第４年生长开始加快，胸径最大年生长量为３．１ｃｍ，年生长主要在６月下旬至８月中旬，各旬生长量基本一致，平均为０．３ｃｍ。通过对Ｉ—４５杨生长规律的观察，可为林木速生丰产、科学管理提供依据。     

应用DRIS法对1年生苗木壤营养诊断及对策

应有ＤＲＩＳ方法对１年生长刺槐（Ｒｏｂｉｎｉａｐｓｅｕｄｏ－０ａｃａｃｉａＬ．）苗木，土壤营养程度进行了诊断，采用ＤＲＩＳ诊断图，确定叶片氮指标为－７．０～６．７，磷－７．８～７．１，钾－６．７～７．３，营养最平衡，生长最好，同时对土壤施肥诊断得知，氮，磷，钾比近似１４：１：４最合理，试验表明，施水素５．０ｇ／盆，磷肥１０．０ｇ／盆，钾肥２．０ｇ／盆苗木营养最平衡，地径生长达１．４２ｃｍ，诊断合理     

离蕊金花茶引种繁殖初报

离蕊金花芯是金花芯组中的北缘种之一,是唯一分布于贵州的濒临灭绝的种;引种繁殖结果表明,在黄习土上扦插,用ＡＢＴ（１）１５０ｇ／ｍ＾３处理１０ｈ生根率可达８７．５％,用苗砧法嫁接成活率高达９５％,种子繁殖时,场圃发芽率在７８．０％－９０．０％之间,１的生苗平均高１８．６ｃｍ,平均地径０．４０６ｃｍ,３年生苗平均高５２．９ｃｍ,平均地径０．９２７ｃｍ。     

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.