混生于德惠,榆树林带中欧美杨类与西十加杨生长情况的调查

林业坚持“以选为主,选、引、育密切结合”的方针,不断试验研究,更新优化造林树种是非常必要的。近年来,我们在德惠、农安、榆树等县(市)林带中发现零星混生的欧美杨类与西十加杨,其各项生长指标都明显好于当地主栽树种北京杨和双阳快杨。据调查西十加杨     

大叶栎容器育苗基质选择

为筛选经济、环保、节约型大叶栎容器育苗基质,采用沤制锯末、炭化稻壳、腐熟的稻草秸秆等材料,以不同比例配制成6种基质,开展大叶栎容器育苗试验,测定半年生苗木的苗高、地径及侧根数,并对基质配方进行综合评价。结果表明:不同配方基质上生长的苗木,其苗高、地径及侧根数差异极显著;Ⅳ号基质(50%炭化稻壳+25%珍珠岩+25%黄心土)育苗效果最好,Ⅲ号基质(50%炭化稻壳+25%腐熟的稻草秸秆+25%黄心土)次之;Ⅳ号和Ⅲ号基质上的苗木苗高、地径以及侧根均生长良好。这2种基质均适宜用于大叶栎容器育苗。     

不同基质对三种樟科植物种子萌发及幼苗生长的影响

以河沙、草木灰、锯末配成的三种栽培基质为试验材料,以黑壳楠、楠木、闽楠为供试品种,采用露天播种育苗的方式,研究不同基质对三种樟科植物种子的萌发、幼苗生长情况的影响.结果表明:黑壳楠在河沙中的发芽率、发芽指数最高,幼苗生长情况最好;楠木和闽楠在河沙+草木灰的基质中萌发情况和幼苗生长情况最好.     

7个油茶品种的生长结实比较

引进岑软2、岑软3、桂无1号、2号、3号、4号、5号等7个油茶品种,在种植后第4年,对树高、冠幅、单株产量、果实纵横径、果皮厚度、含油率等指标进行测定。结果表明:桂无2号单株产量最高;桂无4号树体最高;岑软3号冠幅最大且果实内种子数最多,但出仁率最低;果实普遍是椭圆形且横径大于纵径;桂无5号出仁率高但果皮最厚;桂无1号种仁含油率最高,但种子数少。通过主成分分析法,发现岑软3号的潜在价值和效益最大。油茶在佛山生长情况良好,岑软系列生长比桂无系列生长更好,更适合佛山当地的自然条件。     

吉林省品种杨品种(系)抗病性评价研究

在吉林省双辽品种杨基因收集圃中对参试的88个品种(系)进行抗病性测定,结果表明:抗叶锈病品种(系)为小×钻杨、白林2号杨、富锦3号杨、5号杨、晚花杨、西+加杨、迎春5号杨、81-10号杨、中林299杨、里普杨、7号杨、W-14杨、18号杨、长春加拿大杨、加型杨、2号杨、昭林200杨、白城42号杨、黑林2号杨、黑林1号杨、辽育2号杨、黑×小(选)杨、86-24号杨、1号杨、加×美杨,抗黑斑病品种(系)为西+加杨、白林3号杨、迎春5号杨、W-14杨、小×钻杨、晚花杨、加雌杨、88-13号杨、98-22号杨、33号杨、47号杨、大凌河220杨、辽育2号杨、加×美杨、中林299杨、山海关杨、黑林1号杨、吉林加拿大杨、鲁山杨、5号杨、美×中杨、83-25号杨、摩里佛拉健杨、白城4号杨、黄快杨、黑×小(选)杨、马里兰德×小黑杨、81-10号杨、加型杨、荷兰3934号杨、(美×黑)×健杨、莫斯科加拿大杨、新生×小黑50杨、小×加暴638杨、长春加拿大杨、舍伯吐杨、美×小47杨、龙荷夫健杨、107号杨、格尔里杨、小青×美杨、富锦3号杨、98-30号杨、白城41号杨、健杨、黑×19杨、白城42号杨、N119杨、86-24号杨,以上是吉林省品种杨杂交育种较理想的抗叶锈病及黑斑病亲本。     

平欧杂种榛在山西不同地区的适应性分析

以3年生平欧杂种榛辽榛3号和达维为试材，观测其在山西不同地区的生长情况和结果情况，分析平欧杂种榛的适应性。结果表明，从生长情况可以看出，辽榛3号和达维平欧杂种榛均能基本适应山西省南部和北部的气候条件，树高、地径等均显著增加，山西南部条件更适宜平欧杂种榛生长。其中，达维在山西省南部和北部的生长情况均优于辽榛3号。从结果情况可知，截至2022年，辽榛3号和达维在天镇县没有结果，在夏县结果情况较好。综上，山西南部的气候条件更适宜平欧杂种榛生长和结果。     

10个美国紫薇家系苗期生长规律分析

以美国紫薇10个家系1 a生实生苗为研究对象,探讨其高生长节律,旨在为紫薇的选择育种研究提供参考。对各家系苗高生长进程分析表明,紫薇不同家系苗高年生长规律基本一致,呈现"慢-快-慢-快-慢"的生长节律,2个生长高峰期为7月中下旬至8月初、8月下旬至9月初,其苗高生长量约占全年生长量的40%~50%;对10个家系的苗高、地径生长性状分析结果表明,家系间苗高、地径生长差异极显著,苗高、地径生长最大的2号、6号家系分别高出生长量最小的4号、7号家系150%和49%。各家系内单株之间也存在丰富的变异,苗高平均变异系数为30.9%,地径平均变异系数为22.35%。家系间、家系内存在较为丰富的变异,预示着具有较大的选择潜力。     

基肥对油茶幼林地径和冠幅生长的影响

为了探究基肥对油茶幼林地径、冠幅生长的影响,以油茶优良无性系长林40号新造林为试材,通过施入不同类型基肥配方进行正交施肥试验,并对2008年~2012年油茶幼林的地径、冠幅增长量与不同类型基肥及配方的关系进行方差分析。结果表明:基肥对油茶幼林地径、冠幅的生长起关键作用,复合肥和菜枯肥作基肥施入能够显著提高油茶幼林的地径和冠幅生长量,且基肥的有效时间可持续5 a;油茶幼林最佳基肥配方为钾肥0.78 kg/株+菜枯肥3.49 kg/株+磷肥1.61 kg/株+复合肥0.93 kg/株。     

喷施叶面肥对棚栽辣木生长和产量的影响

比较施用叶面肥对大棚基质栽培辣木生长和产量的影响,结果表明:5种叶面肥与对照相比均能不同程度地促进辣木生长,但差异不显著;各处理均能极显著提高鲜叶产量,其中千叶液肥1号+2号600倍液处理比对照增产41.11%,显著地优于其他处理和对照;其他处理的效果依次为千叶液肥1号600倍液,大肥宝600倍液,狮马叶翠1 000倍液,一遍绿750倍液。     

澳大利亚湿加松F2代在广东早期生长表现

对广东省西江林场、银盏林场、通门林场、浸潭大树墩和龙坪林场等利用澳大利亚昆士兰F2代种子营造的湿加松幼林的生长状况和立地条件进行调查,分析幼林树高、地径或胸径生长与立地条件的关系。结果表明:在高温多雨的广东地区,F2代湿加松具有广泛的适应性。3年生时的树高及胸径分别比同年龄的湿地松大20.26%和27.27%。坡位、坡向、表土层厚度等因素对湿加松幼林的生长起着重要的作用。广东省的地理环境和气候状况适宜湿加松的生长。澳大利亚引进的F2代湿加松在广东省种植后生长情况较好,有着良好的发展前景。     

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.