岷江上游干旱河谷岷江柏木幼林地绿肥种植研究

在岷江上游干旱河谷岷江柏木幼林地经过连续4 a利用雨季种植绿肥压青,增加土壤肥力,提高水分利用率,促进幼树生长研究。结果表明:(1)种植红豆草的土壤0～40 cm含水量旱季增加3.68 g·kg-1,0～20 cm土壤容重降低0.07 g·cm-3;种植草木樨土壤0～40 cm含水量旱季增加4.18 g·kg-1,0～20 cm土壤容重降低0.05 g·cm-3;种植沙打旺土壤0～40 cm含水量增加2.46 g.kg-1,0～20 cm土壤容重降低0.18 g·cm-3。(2)种植绿肥压青,土壤有机质增加0.37 g·kg-1～0.55 g·kg-1,土壤CaCO3含量下降0.66 g·kg-1～1.36 g·kg-1,有效氮增加4.5 mg·kg-1～18.5 mg·kg-1,有效磷含量增加1.0～3.46 mg·kg-1,CEC比对照增加0.54～0.58mg.100g-1。(3)种植红豆草、草木樨、沙打旺绿肥压青对岷江柏木树高、地径生长有显著的促进作用,尤其种植红豆草的岷江柏木幼树生长最好,高、径生长为对照的1.7倍和1.6倍。     

植物生长调节剂对临泽小枣根蘖苗移栽效果的影响

为提高临泽小枣根蘖苗移栽成效,开展了不同植物生长调节剂处理下的根蘖苗移栽试验。结果表明:采用30 mg·kg-1的GGR6号对临泽小枣根蘖苗浸根2 h处理,其根蘖苗移栽的成活率比保水剂处理和对照分别提高26.8和33.3个百分点,新梢生长量分别提高65.7%和96.1%,新生根数分别增加51.92%和64.58%,根长分别增加了13.8 cm和18.7 cm。植物生长调节剂处理提高临泽小枣根蘖苗移栽效果明显。     

斑叶海桐扦插繁殖技术

研究了不同促根剂和不同基质配方对斑叶海桐扦插苗及容器苗的生根和新梢生长的影响.结果表明:发根率和新梢生长量以ABT1号生根粉1000mg/kg和“森生1号”500mg/kg速蘸2s为较佳,比对照分别增加44.4％和36.1％,发根率分别达到86.67％和81.67％,而对照仅为60％;基质配方B1、B2、B3依次排列,对斑叶海桐的新梢和根系生长有明显的促进作用.     

干旱地带侧柏幼林地绿肥种植研究

经过连续4a在干旱地带抗逆性树种侧柏幼林地上利用雨季种植绿肥压青,增加土壤肥力,提高水分利用率,促进幼树生长研究,结果表明:(1)种植红豆草的土壤0~40cm含水量旱季增加3.68g.kg-1,0~20cm土壤容重降低0.07g.cm-3;种植草木樨土壤0~40cm含水量旱季增加4.18g.kg-1,0~20cm土壤容重降低0.05g.cm-3;种植沙打旺土壤0~40cm含水量增加2.46g.kg-1,0~20cm土壤容重降低0.18g.cm-3。(2)种植绿肥压青,土壤有机质增加0.37g.kg-1~0.55g.kg-1,土壤CaCO3含量下降0.66g.kg-1~1.36g.kg-1,有效氮增加4.5mg.kg-1~18.5mg.kg-1,有效磷含量增加1.0mg.kg-1~3.46mg.kg-1,CEC比对照增加0.54mg.kg-1~0.58mg.100g-1。(3)种植红豆草、草木樨、沙打旺绿肥压青对抗逆性树种侧柏树高、地径生长有显著的促进作用,尤其种植红豆草的侧柏幼树生长最好,高、径生长为对照的1.7倍和1.6倍。     

不同肥料配比对金红苹果营养生长的影响

试验以金红苹果为研究对象,研究不同肥料配比对苹果新梢生长和根系分布的影响。发现不同施肥处理均较对照显著提高了苹果的新梢生长量、单位面积吸收根和总根量。化肥对苹果新梢生长量、根系生长和分布的贡献率为:氮肥磷肥钾肥,全肥料处理促进了苹果树地上部新梢生长,并改善了吸收根在20~60cm土层内的分布,增加了土壤深层吸收根和总根数。     

多效唑调控观赏竹生长的初步研究

竹笋施用多效唑后,对其新梢日平均生长量及成竹后全竹高,枝下高、节间长、叶面积均有显著的抑制作用,注射处理在浓度300～800 mg·kg-1,喷施处理在浓度300～1000 mg·kg-1范围内,随处理浓度递增,抑制作用更为显著.应用多效唑能提高观赏竹的观赏价值,解决盆景制作的矮化及枝叶美化问题.     

岷江上游干旱河谷油松刺槐混交林研究

经过连续6a对岷江上游干旱河谷油松刺槐混交林分的土壤水分、养分、理化性质及林冠结构和效益研究,结果表明:(1)混交林土壤0~40 cm平均含水量比油松纯林增加0.91 g·kg-1、比刺槐纯林增加0.55 g·kg-1;(2)混交林18年后土壤容重比油松纯林减少0.13 g·cm-3、比刺槐纯林土壤容重减少0.10 g·cm-3;(3)混交林土壤有机质比纯林增加0.54 mg.kg-1~1.48 mg·kg-1、土壤碳酸钙含量比纯林减少0.43 mg·kg-1~1.09 mg.kg-1、土壤有效氮比纯林增加6.4 mg·kg-1~19.4 mg·kg-1、土壤有效磷比纯林增加0.36 mg·kg-1~1.37 mg·kg-1、土壤有效钾比纯林减少6.90 mg·kg-1~23.90 mg·kg-1,土壤CEC含量比纯林增加0.23 mg·100 g-1~0.85 mg·100 g-1;(4)混交林林冠面积、林冠厚度、林冠水分截留率分别比纯林提高47.83%~78.95%、40.63%~73.08%、6.15%~8.32%,枯落物饱和持水量是纯林的1.62倍~4.22倍;(5)混交林中油松的树高、胸径比纯林分别提高24.7%和27.35%,混交林年均利润是纯林的7.12倍。     

GGR在欧美108杨扦插育苗上的应用试验

采用绿色植物生长调节剂GGR进行欧美108杨扦插育苗试验,结果表明,GGR6号和GGR10号500mg·kg-1处理插穗,均能有效促进欧美108杨的地径和高生长,提高了成活率,各处理间苗高、成活率差异达显著水平,地径达到极显著水平,但以GGR6号效果最好,高生长比对照增加17.6%,地径生长较对照增加34.5%,扦插育...     

葡萄专用肥施用量对葡萄生长及产量的影响

以"红提"葡萄为试材,通过随机区组试验设计,分析了葡萄专用肥使用量对"红提"葡萄新梢生长和产量的影响。结果表明,葡萄专用有机肥施用量为6kg/株时,新梢长度及新梢节间长度达到了最大值,分别为92.34cm、15.56cm,分别比对照提高了19.39%、39.91%。对照新梢粗度最小为0.58cm,施肥量为8kg/株时,单粒质量、单穗质量、单位面积产量均达到了最大值,分别为11.43g、835.68g、32 696.64kg/hm~2,分别比对照提高45.60%、19.51%、30.22%。多重比较结果表明,当施肥量在6~8kg/株时,新梢生长及产量差异不显著,生产上建议葡萄专用有机肥施用量为6kg/株。     

沼肥在枣树上的综合应用试验

沼肥连续2a在枣树上应用表明:使用沼肥的枣树叶色浓绿,叶片厚而亮,新梢平均生长量分别比施用磷酸二氢钾和对照增长5.6cm和7.3cm;施用沼肥、磷酸二氢钾和对照平均单果质量分别为14.1、13-3和11.1g;施沼肥处理单株产量比对照增产16.29%,施磷酸二氢钾单株产量与对照比增产14.38%.从外观上看,施用沼肥与...     

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.