不同育苗基质对白榆长根苗生长的影响

本研究以大田原土基本材料,通过添加不同比例的河沙、草炭、珍珠岩、蛭石,配制出5种不同的育苗基质。将这些基质填充到导根筒(直径10cm、长1m的PVC管)中以培育白榆(Ulmus pumila L.)长根苗。通过分析比较不同育苗基质条件下白榆的地上部、地下部、总生物量以及地下/地上部生物量等生长指标,在遵循育苗基质的适用性和经济性的基础上,筛选出培育白榆长根苗的适宜基质。结果表明:基质S3(大田原土60%+河沙10%+草炭10%+珍珠岩10%+蛭石10%)为最佳育苗基质。     

秸秆轻基质沙地赤松育苗技术研究

为寻找一种既能替代不可再生资源草炭,又能保证育苗质量的新轻基质原料,以沙地赤松为对象,进行了秸秆轻基质、草炭土、木屑、沙土不同配比的育苗基质试验。结果表明,无论是播种苗还是移植容器苗,相同配比的腐熟秸秆基质与草炭基质的苗木质量相差无几,说明在沙地用秸秆轻基质代替草炭培育沙地赤松苗木是可行的。     

不同育苗基质对白榆长根苗生长的影响

以大田原土为基本材料,通过添加不同比例的河沙、草炭、珍珠岩、蛭石,配制出5种不同的育苗基质.将这些基质填充到导根筒(直径10cm 长1m 的 PVC 管)中以培育白榆(Ulmus pumila L)长根苗.通过分析比较不同育苗基质条件下白榆的地上部、地下部、总生物量以及地下/地上部生物量等生长指标,在遵循育苗基质的适用性和经济性的基础上,筛选出培育白榆长根苗的适宜基质.结果表明:基质 S3(大田原土60%+河沙10%+草炭10%+珍珠岩10%+蛭石10%)最佳     

青钱柳MPT苗型育苗技术初步研究

本文对青钱柳MPT苗型(根坨苗)育苗技术进行了初步研究。研究表明用GA100mg·L~(-1)处理种子10h可使62%种子提早1年发芽,缩短了培育时间;采用128穴、72穴和50穴塑料穴盘培育青钱柳60d龄苗,进行两段育苗,移栽成活率100%;用泥炭、森林腐殖土、树皮粉、腐熟厩肥配制的营养基质均可提高根坨苗质量;用根坨苗造林,其造林成活率比裸根苗提高23.2%。     

不同育苗基质配比对葡萄扦插生根和枝条生长量的影响

利用河沙、秸秆颗粒、锯末、腐熟羊粪、草炭、腐殖土和耕作层土壤为原料,配制了不同葡萄(Vitis vinifera)扦插育苗基质,研究不同育苗基质对葡萄插条生根和枝条生长量的影响。结果表明:秸秆+腐熟羊粪+耕作层土壤配制成的葡萄扦插育苗基质的地温,插条生根率、生根数、根长、根粗和新生枝条的粗度最高,分别为17.8℃、92.7%、19.0条/株、29.4cm、3.5mm和12.8mm,且生产成本最低,为60元/m~3。建议在秸秆和牛羊粪资源丰富的葡萄栽培区可利用秸秆+腐熟羊粪+耕作层土壤配方配制葡萄扦插育苗基质和培育葡萄苗木。     

马占相思育苗容器与基质的选择试验

马占相思采用３种容器和９种配方基质育苗试验，结果表明：３种容器育苗对苗高，地径，根鲜重和根瘤数存在显著影响，其中以塑料薄膜育苗袋育生长最快，舒根型软育苗器次之，舒根型硬质塑料育苗筒最短，但根素发达，结根瘤最多；９种配方基质中以７０％黄芯土＋２８％火烧土＋２％过磷酸钙的苗木生长最好，结瘤量也多，根瘤数略次于含４０％锯木糠＋５８％黄芯土＋２％过磷酸钙基质的，苗木生长量总趋势是含火烧土基质〉含泥炭土基质     

不同育苗基质对油茶芽砧嫁接苗生长的影响

通过对几种育苗基质对油茶芽砧苗成活率、苗高、地径以及根系等生长指标对比分析的结果表明,在4个基质配比中,1 a生芽砧嫁接苗以油茶轻基质容器苗保存率、树高和地径表现为最大,分别为82.2%,32.1 cm和0.31cm;苗木根系以2 a生大田裸根苗主根为最长,为13.3 cm,根茎比最大,为0.50,适宜油茶造林后后期生长。因此培育1 a生油茶苗以油茶轻基质为最佳选择,培育2 a生苗应该选择大田育苗。     

侧柏塑料营养袋二级育苗与造林

淄博市淄川区位于泰沂山北麓,是以石灰岩山地为主的山区,多以侧柏营造水土保持林。前几年,采取大田育苗,雨季用裸根苗造林的方法,造林成活率很低,有时不足40％,甚至失败。为了解决这个问题,我们借鉴侧柏塑料营养袋种子育苗的做法,进行了侧柏塑料营养袋二级育苗和造林试验。现将试验结果总结如下。     

育苗基质和育苗条件对梭梭播种育苗的影响

为了研究不同基质和育苗条件下对梭梭生长发育的影响,以梭梭为材料,比较了3种不同基质配置和两种育苗条件对梭梭生长状况的影响。结果表明:小拱棚育苗和露天育苗条件下,最佳播种育苗基质均为园土∶河沙∶腐熟羊粪=1∶1∶1;同种基质下,小拱棚育苗方式均比露天育苗方式下苗木生长好。播种时,采用小拱棚营养袋育苗方式、播种基质以园土∶河沙∶腐熟羊粪=1∶1∶1的苗木生长量最好。苗木平均苗高、平均地径、平均主根长、一级侧根长、苗木重量分别达39.28 cm、0.19 cm、11.83 cm、7.45 cm、6.87 g。     

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。     

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.