试析杉木优良无性系扦插育苗试验

对屏南县路下乡杉木优良无性系扦插育苗实验分别在4月10日、5月10日、6月10日进行了扦插,在培育过2年杉木的相应扦插苗圃地以及1年水稻轮作的相应圃地上对杉木优良无性系这种扦插育苗方法进行了试验。试验结果显示:在4月和5月进行扦插的苗木质量和成活率都明显比6月扦插的高,其中在4月扦插的杉木苗木质量最好。在扦插时间一样的条件下,轮作过的圃地中杉木苗木生长质量显著高于没有经过轮作的圃地中杉木苗木生长质量。     

杉木不同育苗方式苗木生长比较分析

为了解不同育苗方式培育的杉木苗木生长差异,以杉木优良无性系扦插裸根苗、杉木第3代种子园实生裸根苗和杉木第3代种子园实生轻型基质容器苗为研究对象,以杉木第3代种子园实生轻型基质容器苗为对照(CK),于2021年12月测定了不同育苗方式培育的苗木生长量,分析了不同育苗方式培育的苗木生长差异,结果表明：杉木无性系扦插裸根苗相对对照(CK)的苗高、地径分别增长了117.2%和155.9%;杉木第3代种子园实生裸根苗相对对照(CK)的苗高、地径分别增长了74.8%和135.3%,综合对比分析杉木优良无性系扦插裸根苗生长最优。     

杉木优良无性系繁殖技术

为营造杉木速生丰产林提供优质苗木,加速杉木优良无性繁殖工作,贵池区苗圃建立优良无性系原种圃2亩,无性系测定圃3亩,采穗圃13亩,扦插繁殖圃12亩,预计可采优良无性系穗条120多万根,繁殖优良扦插苗木40多万株,每年可供营造杉木速生丰产林8190多亩.该地区交通方便,光照充足,易于排灌,土壤条件适应杉木苗生长.根据本人在贵池苗圃培育实践,总结繁殖技术如下.     

杉木优良无性系繁殖技术

为营造杉木速生丰产林提供优质苗木,加速杉木优良无性繁殖工作,贵池区苗圃建立优良无性系原种圃2亩,无性系测定圃3亩,采穗圃13亩,扦插繁殖圃12亩,预计可采优良无性系穗条120多万根,繁殖优良扦插苗木40多万株,每年可供营造     

广东省地方标准杉木无性系扦插育苗技术（征求意见稿）

广东省地方标准杉木无性系扦插育苗技术（征求意见稿）ＤＢ／４４００００—９２１主题内容与适用范围本标准规定了杉木杆插育苗的采萌圃建立、管理、扦插以及苗木出圃等技术。本标准适用于杉木无性系扦插育苗。２名词术语２．ｌ无性系由同一树木营养繁殖出来的所有分株总...     

杉木采穗圃营建和扦插育苗技术

目前在我省杉木优良无性系林业的推广中，有的地方不遵循育种程序，忽视科学性，致使出现苗木产量低、质量差的弊端。据我省著名杉木专家陈佛寿等人研究实践，主要是没有搞好采穗圃的营建和扦插育苗。现将两方面的技术要领介绍如下：一、采穗圃的营建技术1．圃地要选建在适宜杉木生长、坡度平稳、土壤疏松肥沃、排水良好、日照长、不当北风、可防冻害、牛害的地点。建圃材料一定要选用遗传品质好的优良无性系；为便于今后组合多个无性系造林，一个建圃单位选用的无性系不得少于10个。2．整地作床。于建圃前夏、秋季全面深挖整地、清除草根。…     

楝树嫩芽扦插育苗技术研究

为早日实现用优良无性系苗木造林,必须采用无性繁殖方法育苗。1986年用我省已选出的一批楝树优良无性系进行嫩芽扦插育苗试验。嫩芽采用根生芽,扦插前用生长素处理,6月份以前扦插、移载,成活率可达90%。当年苗高达2米以上,地径粗2厘米以上,可出圃造林。     

杉木扦插育苗插穗类型选择试验

扦插育苗是当前发展杉木无性系林业的主要繁殖手段,在杉木无性系扦插繁殖中,不同类型的插穗因存在位置效应,不仅影响扦插成活率,而且影响到苗木和幼林的高、径生长。可见,正确选用插穗类型对于保证杉木无性系造林成效具有至关重要的意义。 几年来,我们结合四川省林科院杉木组布置的杉木优良无性系选育工作,进行了插穗类型选择的初步试验研究,现将其结果报道如下。     

杂交柳育苗技术初探

通过对不同圃地、不同无性系、不同育苗方式的杂交柳育苗试验研究，圃地和育苗方式对杂交柳苗木生长影响显著。圃地最好选择土层深厚、水源有保证的农田，育苗方式以1年生扦插、3～4年生蔸萌为最佳模式。     

杉木优良无性系快速育苗取得重大突破

浙江省开化县林场近年来成功地研究出一套杉木优良无性系快速繁殖育苗新技术,按照这种办法,一株杉木优树经过4年繁殖可得22万株以上的无性系苗木。如果用0.5公斤杉木良种种子冬播育苗,春季3—4月进行段插,当     

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.