棘茎楤木根段扦插繁殖技术研究

为探索棘茎楤木(Aralia echinocaulis Hand.-Mazz.)最佳的根段扦插繁殖技术,采用单因素对比试验,研究了不同根段长度、粗度、生根剂种类及浓度、处理时间对扦插成活率及成活植株生长的影响。结果表明,棘茎楤木根段扦插成活率随插穗长度的增加而增加,随插穗粗度的增加、生根剂(NAA、ABT生根粉)处理浓度的升高以及根段ABT浸泡时间的延长先升高后下降;相同浓度的ABT生根粉处理显著高于NAA。棘茎楤木根段扦插最佳的条件为根段插穗长15 cm、粗5~7 mm、ABT生根粉浓度100mg·L―1、浸泡时间2 h。不同处理对扦插成活植株的苗高和地径影响规律不明显。     

沙棘插穗处理对扦插育苗成活率的影响

研究了沙棘插穗长度、剪切方式、生长调节剂的应用对扦插成活率的影响。结果表明:以15 cm段为最佳硬枝扦插插穗剪切型式;以留3~4片叶、15 cm梢为最佳嫩枝扦插插穗剪切型式,同时得出,100 mg/L ABT1号生根粉浸泡4 h处理对硬枝插穗效果较好,50 mg/L ABT生根粉浸泡8 h对嫩枝插穗效果较好。     

4种生长调节剂对三角梅扦插生根的影响

2009年在昆明市松花坝苗圃地,以三角梅4年生健壮母树上1年生枝条为插穗,利用不同浓度（50 mg/L、100 mg/L、150 mg/L、200 mg/L）的4种生长调节剂（ IAA、 IBA、 ABT1、 NAA）分别处理三角梅插穗后进行随机区组扦插试验,调查各生长指标,并进行方差分析。结果表明,相同条件下,不同生长调节剂的不同浓度水平对三角梅插穗的影响不同,以IAA 50 mg/L浸泡24 h的插穗,扦插生根效果最好,平均生根数为18根,平均根长为3.95 cm,生根率为91.67％;用100 mg/L的IAA处理的插穗,扦插生根效果次之。4种生长调节剂处理插穗的生根效果依次为IAA、 IBA、 ABT1、 NAA,均显著优于对照。     

影响互叶醉鱼草硬枝扦插成活因素的研究

以互叶醉鱼草1～2年生枝条为穗条,通过不同采穗时间,以不同枝条部位作插穗,不同激素处理插穗的单因素试验和激素种类、激素浓度、枝条部位3因素组合的正交试验,进行了影响互叶醉鱼草硬枝扦插成活因素的研究.结果表明:采穗时间、采穗部位、激素处理插穗均对互叶醉鱼草硬枝扦插的成活率,成活苗的平均根数、平均根长有极显著影响(P＜0.01).以4月5日采穗,选用1～2年生健壮的互叶醉鱼草枝条的基部作插穗,用200 mg/L的ABT1对插穗浸泡处理2 h,其扦插的效果最佳,扦插后60天,扦插成活率达85.4 %,新枝生长量达13.6 cm.     

萘乙酸对金银花扦插成活的影响

采用两因素完全试验设计研究萘乙酸不同浓度(0、20、40、60、80、100、120mg/L)、不同浸泡时间(1、3、5h)对金银花(Lonicera japonica)插穗成活和生根的影响,结果表明:萘乙酸浓度对金银花插穗成活株数和生根数分别有极显著和显著影响,浸泡时间对成活株数和生根数都无显著影响。根据成活和生根情况并考虑时间因素和人力成本,T3(浓度为40mg/L,浸泡时间为1h)为最佳的扦插处理。     

武当木兰嫩枝扦插育苗初步研究

采用随机区组试验设计,对武当木兰进行嫩枝扦插育苗实验,结果表明,不同基质、ABT 1号生根粉不同质量浓度对插穗成活率影响显著,提高嫩枝扦插成活率的最佳处理组合为:以混沙土为基质、100mg/L的ABT 1号生根粉溶液浸泡12 h,成活率、平均生根数、平均根长最高,分别比对照高出20个百分点、7.0条和8.3 cm。     

不同基质和激素处理对海南油茶扦插育苗的影响

不同基质和激素处理对海南油茶扦插育苗试验结果表明,以红土为基质,NAA100mg/L浸泡处理6h是提高扦插成活率的最优处理组合,成活率大于74.0%,效果最好。具体看,混合土为基质,IBA300mg/L浸泡处理4h,平均根数大于24.0条/株,是促进扦插生根的最优处理方法。以混合土为基质,NAA100mg/L浸泡处理6h促进根长的效果最佳,处理插穗的平均根长为6.2cm。     

东北红豆杉快速扦插育苗技术试验

该文分析了利用ABT-1号生根粉的不同处理方式(速蘸或浸泡)对来自不同龄母树的东北红豆杉插穗扦插成活率的影响。处理方式为ABT-1号生根粉1 000 mg/L溶液速蘸和ABT-1号生根粉100 mg/L溶液浸泡30 min 2种,对照处理为清水浸泡;插穗分别选择来自3年生和30年生东北红豆杉母树的当年生嫩枝。试验结果表明:ABT-1号生根粉处理东北红豆杉当年生嫩枝插穗,可明显提高扦插成活率;在0.05显著性水平下,ABT-1号生根粉不同处理方式对扦插成活率影响差异显著,不同龄母树对扦插成活率影响差异未达到显著性水平。综合结果,认为用ABT-1号生根粉1 000 mg/L溶液速蘸3年生东北红豆杉幼树当年生嫩枝为较佳扦插方式,扦插成活率可逾95%。     

植物生长调节剂对枸杞硬枝插穗发根及生长的影响

分别采用IAA、ABT生根粉,4种浓度水平,浸泡处理"宁杞1号"枸杞硬枝插穗进行扦插试验,结果表明:2种植物生长调节剂溶液质量浓度为100 mg.L-1,浸泡2 h对提高硬枝插穗成活率、促进枸杞扦插苗根、茎、叶的生长发育效果最好。     

美国红叶紫薇扦插技术研究

以红叶紫薇当年生枝条为试验材料,开展了扦插基质、插穗木质化程度、植物生长调节剂种类及其浓度对红叶紫薇扦插生根的影响试验。结果表明:红叶紫薇扦插较适宜的基质为泥炭土∶珍珠岩=1∶1,其扦插成活率为97%;插穗以半木质化程度较好,扦插成活率达99%;插穗基部采用NAA、IBA、IAA、ABT6、KIBA处理,均是速沾比浸泡效果好;采用KIBA速沾处理较适宜的浓度范围是1 000～2 000 mg/L,其扦插成活率可达95%以上。     

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.