不同防风措施对赤皮青冈容器苗的抗风效果

在模拟自然风的情况下,对4年生赤皮青冈容器苗在无任何抗风措施、搭支架、半埋入地下、半埋入地下兼搭支架、半埋入地下兼连体绑扎等处理下的形态特征变化、风害情况以及抗风指数进行了研究和分析.结果表明采取半埋入地下兼连体绑扎措施时4年生赤皮青冈容器苗受到的风害最小,抗风等级最高,其次分别为丰埋入地下兼搭支架、半埋入地下、搭支架和无任何抗风措施.因此建议沿海地区进行赤皮青冈容器苗生产时,可采取半埋入地下兼连体绑扎措施来防御台风.     

植物生长调节剂对赤皮青冈扦插生根的影响

以赤皮青冈(Cyclobalanopsis gilva)插穗为试验材料,通过扦插育苗试验探讨了不同浓度、不同类型生长调节剂作浸穗处理对赤皮青冈扦插苗生根率、平均根长、平均生根数的影响。研究表明:(1)同种条件下,与清水浸穗处理的对照相比,以GGR、IBA、IAA3种生长调节剂不同浓度对赤皮青冈的生根率、平均根长、平均生根数具有明显的促进作用。(2)3种生长调节剂类型处理的赤皮青冈插穗的生根率、平均根长、平均生根数3个指标均在100~300 mg/L时达到峰值,表明3种生长调节剂对赤皮青冈浸穗处理的最适浓度在200 mg/L左右。其中200 mg/L GGR效果最好,生根率68.4%,平均根长3.52 cm,平均生根数5.55条;IBA与IAA效果相近且次之,200 mg/L IBA处理的生根率50%,平均根长2.82 cm,平均生根数2.34条;200 mg/L IAA处理的生根率51%,平均根长3.83 cm,平均生根数2.52条。     

针叶林不同保存密度赤皮青冈与米槠生长效果分析

人工针叶纯林成熟林分主伐择伐后,对20株/亩(A)、30株/亩(B)、40株/亩(C)3种不同保存密度林冠下采用赤皮青冈与米槠2年生无纺布营养袋苗造林效果对比,造林2年的生长量调查结果表明：不同保存密度林下套种的赤皮青冈与米槠造林成活率、地径、高度、冠幅4项指标均以A最高,平均造林成活率达96.4%,赤皮青冈平均地径达2.21 cm,平均高达177.7 cm,平均冠幅达106.0 cm;米槠平均地径达2.07 cm,平均高达224.6 cm,平均冠幅达133.6 cm; 4项指标大小次序为A>B>C。     

缓释肥 × 菌根菌对赤皮青冈容器苗生长性状和养分状况的影响

目的 基于不同缓释肥添加梯度和接种菌根菌互作试验,分析缓释肥添加和接种菌根菌对赤皮青冈1年生容器苗生长性状和养分状况的作用规律,以提高赤皮青冈容器苗的菌根化育苗水平。 方法 采用裂区试验设计,主区为菌根菌处理,分为接种（育苗容器中间部位注射浓度为36.28 mg·mL−1 的彩色豆马勃10 mL）与不接种2个处理;副区为基质缓释肥添加处理,设置5个缓释肥添加梯度（1.50、2.25、3.00、3.75和4.50 kg·m−3）。 结果 接种菌根菌对不同缓释肥梯度下1年生赤皮青冈容器苗生长均有促进作用,缓释肥添加和接种菌根菌对容器苗总生物量和P利用指数有显著的互作效应。接种菌根菌后,赤皮青冈容器苗苗高、地径、高径比、总生物量、总根长和根系直径等生长性状相比不接种分别增加18.70%、7.16%、10.75%、24.55%、1.02%和18.47%,N含量、N吸收量和N利用指数、P吸收量和P利用指数分别增加2.04%、27.10%、27.67%、19.72%和30.52%,P含量降低2.94%,除总根长和N、P含量外各生长性状和养分状况指标接种和不接种存在极显著差异。无论是否接种菌根菌,随缓释肥添加量增加,除根系直径无明显变化外各生长性状均呈先增加后降低趋势,P含量和P吸收量整体呈增加趋势,在缓释肥添加量为3 kg·cm−3时生长表现最好。不接种菌根菌容器苗N含量和N吸收量呈先增加后降低趋势,N、P利用指数呈先降低后增加趋势,接种菌根菌后N、P利用指数变化趋势正好相反,呈先增加后降低趋势,N含量和N吸收量无明显变化规律。 结论 接种外生菌根菌彩色豆马勃可促进赤皮青冈容器苗的生长,提高N、P养分利用效率,低缓释肥添加量下菌根的促生效应更显著。生产中可通过接种菌根菌提高容器苗质量,同时减少缓释肥使用量,有助于培育赤皮青冈优质苗木并节约育苗成本。     

赤皮青冈容器育苗基质筛选及大田育苗富根壮苗试验

开展了赤皮青冈容器育苗基质筛选及大田育苗富根壮苗试验,结果表明:赤皮青冈容器育苗基质最佳配方为泥炭土:黄心土:钙镁磷肥=50:45:5。赤皮青冈大田育苗不同浓度GGR6对苗木进行叶面喷施处理后,其苗木根长大于5 cmⅠ级侧根数、苗高生长、地径生长均有显著差异。考虑到成本因素,宜采用100 mg/L GGR6喷施叶面且连喷3次,在此处理下,相比对照,赤皮青冈苗木根长大于5 cmⅠ级侧根数增加70%以上,苗高生长增加20%以上,地径生长增加15%以上。富根壮苗出圃率达75%。     

不同生境赤皮青冈种子萌发及幼苗高的生长规律研究

为研究不同生境赤皮青冈的种子萌发及苗期的生长规律。对不同生境的赤皮青冈的年生长节律进行连续观察,采用Logistic方程对苗高的生长动态过程进行拟合,进而获得Logistic模型,划分生长时期。苗圃地的萌发时间为5月27日,比野外的提早一个多月,且幼苗出土率也高于野外,在野外山地,母树林内的赤皮青冈幼苗出土率和保存率最高;苗圃地的赤皮青冈幼苗全年苗高平均值为29.1 cm,远高于野外山地的幼苗苗高平均值。不同生境的赤皮青冈幼苗高的实测数据曲线与拟合曲线基本吻合,生长曲线为典型的“S”型,6个生境的相关系数均达到0.95以上,回归性均达到极显著水平,并将幼苗苗高的生长进程准确地划分为生长前期、速生期和生长后期。在今后的赤皮青冈幼苗管理中,建议在播种后40 d～60 d增加水肥管理,在正午时分盖上遮阳网,创造适宜的条件,以提高后期移栽的成活率。     

氮素添加对赤皮青冈大规格容器苗生长量的影响

为指导培育市场急需的赤皮青冈容器大苗,以2a生赤皮青冈为研究对象,设置4个不同氮素水平(每株施氮 CK 0g,A₁0.144 9g,A₂0.283 8g,A₃0.425 7g),研究不同氮素添加量对赤皮青冈容器苗木生长量的影响。结果表明：苗高、地径、叶总数、叶片长度与宽度以及地上与地下生物量,都表现为随着氮素添加量的增加先增加后减小趋势;A₂处理对苗高、单株叶片数以及叶片、茎、根系生物量最有利,A₁ 处对地径以及叶片长度与宽度最有利。按照本研究采用的营养土来源和配比,利用2a生幼苗培育赤皮青冈容器大苗时,建议每株施氮0.283 8g或0.144 9g。     

鳞苞锥无纺布营养土容器育苗技术

精选优质的鳞苞锥种子进行沙藏,选择圃地,在种子的胚芽刚露头时直接点播到装好配置营养土的无纺布容器中进行了育苗技术试验,苗期加强水肥管理、除草与补苗、病虫害防治、炼苗等。结果表明:鳞苞锥无纺布营养土容器苗当年出圃时平均苗高可达30 cm,平均地径0.3 cm,合格苗出圃率达80%,上山造林成活率可达95%以上。     

木荷等3个树种网袋容器育苗技术

选用木荷、青冈、红叶石楠3个树种,分别采用芽苗移栽、种子直播、扦插进行网袋容器苗与裸根苗的对比育苗试验。结果表明:网袋容器育苗法能有效控制1年生木荷和青冈苗的主根生长,促进须根生长。与浅根性的树种木荷相比,深根性树种青冈经网袋容器育苗后,根质量及其总生物量的比例显著降低,表明网袋容器对青冈的修根作用比较明显。还观察了3个树种的苗木生长规律,并提出了相应的网袋容器育苗技术措施。     

赤皮青冈、闽楠、木荷造林对比试验

2014-2015年,在浙江省缙云县对赤皮青冈(Cyclobalanopsis gilva)、闽楠(Phoebe bournei)、木荷(Schima superba)3种树种进行容器苗和裸根苗在上、中、下3种不同坡位造林试验,并研究其对造林成活率、地径及树高生长量的影响。结果表明:不同树种容器苗造林后树高生长量、地径生长量及造林成活率均显著高于裸根苗;坡位对不同树种造林成活率、地径生长量和树高生长量的影响均表现为下坡中坡上坡;不同树种之间,木荷在各坡位造林的成活率均高于赤皮青冈、闽楠,闽楠则在地径生长量和树高生长量上优势最明显。试验表明容器苗造林可以有效提高造林成活率,下坡造林有利于幼苗更好生长。     

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.