云杉山地青苗技术

云杉,是松科云杉属的常绿乔木.分布于陕西、四川、甘肃等省.耐寒抗旱,是秦岭高山区的主要造林树种之一.陕西省龙草坪林业局中心苗圃,从1979年开始云杉苗木的培育,在更新造林中效果较好.培育的大苗在城市绿化和道路边绿化中也有使用.     

红皮云杉苗木培育技术要点

通过在通化水洞苗圃开展的育苗生产实践,总结了红皮云杉苗木培育的成功经验,详细地探讨了红皮云杉苗木培育的技术要点及其管理措施.     

云杉山地育苗技术

云杉，是松科云杉属的常绿乔木。分布于陕西、四川、甘肃等省。耐寒抗旱，是秦岭高山区的主要造林树种之一。陕西省龙草坪林业局中心苗圃，从1979年开始云杉苗木的培育，在更新造林中效果较好。培育的大苗在城市绿化和道路边绿化中也有使用。现就山地育苗技术要点简介如下：一、整地做床选择圃地，在林区要选择地形开阔的阳坡或半阳坡，土层厚度30～40厘米以上，     

谈红皮云杉育苗技术

介绍了红皮云杉种子催芽处理方法、播种技术、苗期管理技术,为红皮云杉苗木培育提供技术支撑,解决了生产中红皮云杉育苗出苗不齐、保苗不力、苗木产量低的问题。     

落叶松冠下培育青木千云杉绿化苗木技术

章通过多年的生产试验，从苗木、立地选择、栽植管理办法到起苗运输等方面，提出了在落叶松冠下培育青杄云杉绿化苗木的技术要点。     

青海云杉在湟水河中下游地区苗木培育规程

青海云杉是青海、甘肃等高原地区主要的森林更新树种,广泛用于退耕还林、城市园林绿化、通道绿化、庭院绿化、新农村美化以及荒山造林。作者介绍了青海云杉这一适生在湟水河中下游地区的树种的苗木培育规程。     

云杉苗期施肥效应的研究

苗木作为人工更新造林的物质基础,一直是林业生产和科研部门所重视的问题。1982年以来,我们对我省主要高山针叶树种进行了以缩短苗木培育周期、提高苗木质量和单位面积合格苗出圃率、降低苗木成本为目的的育苗综合技术试验研究,取得了以2年生云杉原床苗培育工艺代替目前所采用的3—4年生换床苗木培育工艺的初步成果。通过更新造林试验和生产中应用的结果,成活率分别达到95.1％和94.1％,保存率达87.3％。本文根据综合试验中几组施肥试验材料分析整理。文中从肥料要素、施肥量、肥料组合、施肥时间、施肥方法等方面分析了施肥措施对土壤肥力、苗木各种生长指标和形质指标以及苗木群体结构和苗木分化的影响。从而为苗期合理施肥提供了科学依据。试验结果表明,在云杉苗木培育过程中,按照苗木各器管生长发育时期,采用高氮、高磷或中氮高磷与适量的钾互相配合,采用有利于根系吸收的施肥方法(如水施等),并抚以其它合理管理措施,可以获得生长快、发育均衡、质量优良、抗性强和单位面积产苗量高的优良培育效果。     

秦岭林区林木育苗技术初探

分析了秦岭林区特殊的生态环境对苗木培育的影响,从整地改土、土壤消毒、做床、播种育苗、水肥管理、病虫害防治等方面探讨了秦岭林区林木育苗技术。     

吉林地区红皮云杉苗木培育及造林技术

红皮云杉生长速度较快，且具备较好的耐寒、耐旱特性，在东北及华北地区适应性较强，属于吉林地区的主要树种，观赏价值与建筑价值较高。文章从吉林地区红皮云杉种植情况入手，分析了该地区红皮云杉苗木培育方法，提出红皮云杉造林技术要点，为该树种的繁殖利用提供参考。     

谈谈新疆云杉和新疆落叶松种子催芽处理

新疆云杉和新疆落叶松是我区山区分布最广针叶树种,也是我区主要用材树种,在我区林业生产建设上占有重要地位.目前我区营林生产活动中,各山区林场都在从事上述两个树种的苗木培育工作,而且取得了一定的成绩.但云杉和落叶松苗木培育工作中,由于种子粒小,覆土层薄,加之幼苗细嫩,极易遭受恶劣气候及病虫鸟的危害,因此如何处理好种子,以促进种子发芽整齐,缩短幼苗出土期的田间管理,是提高苗木产量和质量重要技术环节之一.     

Litter impair spruce seedling emergence in beech forests: a litter manipulation experiment

European beech Fagus sylvatica and Norway spruce Picea abies are economically and ecologically important forest trees in large parts of Europe. Today, the beech forest reaches its northern distribution limit in south-eastern Norway and it is expected to expand northwards due to climate warming. This expansion will likely result in fundamental ecosystem changes. To increase our knowledge about the competitive balance between spruce and beech, we have investigated how beech and spruce litter affect spruce seedling emergence, growth and uptake of C and N. We did this in a seed-sowing experiment that included litter layer removal as well as reciprocal transplantations of litter layers between spruce and beech forests. Our results show that spruce seedling emergence was significantly impaired by both litter layer types, and especially so by the beech litter layer in the beech forest. The low seedling emergence in beech forests is concurrent with their lower light availability.     

光照条件对绿化树种青海云杉引种的影响

在黑龙江省东南部地区对青海云杉进行不同光照条件引种试验,为青海云杉在黑龙江省作为园林绿化树种引进提供理论基础。试验结果,青海云杉幼苗生长趋于弱光条件,但同时适当的光照可以促进幼树的生长;同一种源的不同个体表现出一定的生长差异,林缘处青海云杉的各项生长指标分布较为平均,变异程度较低。     

欧洲云杉、黑云杉、白云杉苗期对比试验

选择欧洲云杉3个种源、黑云杉3个种源、白云杉3个种源、青海云杉1个种源进行了不同种、种源的苗期生长性状变异试验。结果表明：云杉不同种、种源间苗期性状差异显著。4个种的1年生苗以苗高进行排序：欧洲云杉〉黑云杉〉白云杉〉青海云杉。欧洲云杉、黑云杉、白云杉各个种的不同种源间有很大的变异及选择潜力。因此在进行云杉引种时,应选择不同的种、种源,才能取得更好的效果。     

Quality of growth substrates of post-disturbed lowland black spruce sites for black spruce (<Emphasis Type="Italic">Picea mariana</Emphasis>) seedling growth

Black spruce (Picea mariana (Mill.) BSP) is the most important commercial tree species in the eastern boreal forest of Canada. Only limited work has been conducted to assess the quality of the various substrates that are found on post-disturbed sites prone to paludification having an effect on black spruce seedling growth. The objectives of this study were (1) to use a pot test to assess black spruce seedling performance on substrates found at the soil surface, in the rooting zone of undisturbed soil, at depths that become available to spruce roots after soil disturbance by wildfire or through management; and (2) to determine the nutritional quality of these substrates when constraints of poor drainage are artificially removed. Black spruce growth was greatest with fibric Pleurozium in the rooting zone, and with burned fibric Pleurozium and living Sphagnum at the soil surface. Good seedling growth on different substrates found in the rooting zone was associated with higher N and P foliar concentrations. Based on these results, we recommend targeted planting of black spruce seedlings in substrates of Pleurozium origin and the development of management techniques that promote Pleurozium schreberi. The Canadian Crown’s right to retain a non-exclusive royalty-free licence in and to any copyright is acknowledged.     

Frequencies and patterns of browsing by large herbivores on conifer seedlings

Browsing by large herbivores on planted and naturally regenerated conifer seedlings (Picea abies and Pinus sylvestris) was recorded in 104 clear‐cuts in east‐central Sweden during 1990 and in 47 clear‐cuts in 1991. The number of seedlings browsed and the browsing patterns were analysed in relation to seedling type. Browsing frequencies were also compared between forest stands with different site productivities and subjected to different management practices. The variation in the number of seedlings browsed in 1990 was explained mainly by seedling category. Among both planted and naturally regenerated seedlings, pine was browsed more than spruce. Two‐year‐old containerized seedlings of spruce was browsed more than 4‐yr‐old bare‐rooted spruce. In 1991, browsing was more equal among species and seedling types. Number of seedlings with their leader browsed and the amount of biomass left after browsing differed significantly between seedling types. Seedlings that had been browsed in 1990 experienced significantly higher browsing frequencies in 1991 when compared with unbrowsed seedlings. The effects of stand characteristics were not found to be significant.     

Establishment and growth of white spruce on a boreal forest floodplain: Interactions between microclimate and mammalian herbivory

White spruce (Picea glauca (Moench) Voss) is a dominant species in late-successional ecosystems along the Tanana River, interior Alaska, and the most important commercial timber species in these boreal floodplain forests. Whereas white spruce commonly seed in on young terraces in early primary succession, the species does not become a conspicuous component of the vegetation until after 60–80 years. To address what abiotic and/or biotic factors may explain the paucity of spruce in earlier stages of succession, we examined germination and growth of planted white spruce seedlings across an environmental gradient that included variation in soil physico-chemical properties in the presence and absence of mammal browsing. The effect of browsing pressure over the first four years after planting was most noticeable on the older terraces. Likewise, direct effects of hare browsing on spruce seedling mortality were only manifested at the oldest sites. Spruce germination and survival was inversely proportional to soil cation concentrations, which was largely controlled by temperature-driven evapotranspiration. High light intensities and high air temperatures significantly reduced seedling growth, whereas variation in soil moisture only explained a significant amount of variation in seedling survival. Temperatures within the needle clusters on terminal shoots reached values that adversely affect photosynthesis (>32 °C) on multiple occasions over the growing season. We conclude that the direct (temperature) and indirect (soil chemistry) effects of high insolation are major factors constraining spruce performance on early successional terraces, and that these effects can be significantly exacerbated by mammal browsing on associated deciduous vegetation.     

Interference of bracken (Pteridium aquilinum L. Kuhn) with Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) seedling establishment

The nature of interference of bracken with Scots pine and Norway spruce seedling establishment was considered in three field experiments. In a seeding experiment, it was found that Scots pine germination was highest on exposed mineral soil and lowest when intact bracken litter and humus were present, suggesting adverse effects of litter and humus on pine regeneration probably due to phytotoxicity. In a second experiment, smothering by bracken caused high mortality of Scots pine seedlings while Norway spruce seedlings were relatively unaffected. Mortality for both Scots pine and Norway spruce seedlings was low when planted in a adjacent Scots pine-bilberry stand with no bracken. Annual shoot growth of Norway spruce was higher in bracken than in Scots pine-bilberry vegetation while no differences in shoot growth between these two vegetation types occurred for Scots pine. In a third experiment, activated carbon was added to the ground under Norway spruce seedlings planted in bracken to adsorb possible phytotoxic compounds released by bracken. The addition of carbon had no effect on seedling mortality or growth rate, indicating that the seedlings were not susceptible to allelochemicals released by bracken. Since large Norway spruce seedlings were relatively unaffected by bracken interference in this study, artificial regeneration with containerized Norway spruce seedlings is suggested to achieve an acceptable conifer tree establishment on clear-cuts invaded by bracken.     

Seedling emergence in uneven-aged Norway spruce stands in Finland

The emergence of Norway spruce seedlings on different types of germination sites in uneven-aged Norway spruce dominated stands four years after selection harvesting was studied. The data were collected from 20 stands in southern Finland. In each stand, ground cover was measured from a set of 64 one square metre subplots on a permanent experimental plot of 1600?m². Correlation analysis, direct comparison of subplots with and without seedlings and mixed-effects models were used to estimate the influence of ground and tree cover on seedling occurrence. Grass cover, dwarf shrub cover, cover of certain moss species and close vicinity of trees decreased the occurrence probability and number of seedlings, while greater stand and local basal area around the subplots increased the seedling number. The cover of vegetation free surfaces, usually considered as good germination sites, was rather low. Variation in seedling emergence between plots was high. We concluded that spruce regeneration was slightly more abundant in stands with greater overall stand density and local density within a stand in postharvest conditions.     

Species mixing effect on Norway spruce response to elevated CO2 and climatic variables: root and radial growth response

A 7-year study was conducted to examine the growth (diameter and root) response of Norway spruce (Picea abies (L.) Karst.) seedlings to elevated CO₂ (CO_2ELV, 770 μmol (CO₂) mol^?1) in different mixture types (monospecific (M): a Norway spruce seedling surrounded by six spruce seedlings, group-admixture (G): a spruce seedling surrounded by three spruce and three European beech seedlings, single-admixture (S): a spruce seedling surrounded by six beech seedlings). After seven years of treatments, no significant effect from elevated CO₂ was found on the root dry mass (p?=?0.90) and radial growth (p?=?0.98) of Norway spruce. Neither did we find a significant interaction between [CO₂]?×?mixing treatments (p?=?0.56), i.e. there was not a significant effect of CO₂ concentrations [CO₂] in all the admixture types. On the contrary, spruce responses to admixture treatments were significant under CO_2AMB (p?=?0.05), which demonstrated that spruce mainly increased its growth (diameter and root) in M and neighbouring with beech was not favourable for spruce seedlings. In particular, spruce growth diminished when growing beside high proportions/numbers of European beech (S). Here, we also evaluated the association between tree-ring formation and climatic variables (precipitation and air temperature) in different admixture types under elevated and ambient CO₂ (CO_2AMB, 385 μmol (CO₂) mol^?1). Overall, our result suggests that spruce responses to climate factors can be affected by tree species mixing and CO₂ concentrations, i.e. the interaction between climatic variables?×?admixture types?×?[CO₂] could alter the response of spruce to climatic variables.

     

Regeneration in windthrow areas in hemiboreal forests: the influence of microsite on the height growths of different tree species

Natural regeneration of windthrow areas is an important issue when planning forestry measures after forest disturbances. Seedling recruitment was investigated in storm-damaged hemiboreal mixed forests in eastern Estonia. The establishment and growth of seedlings from natural regeneration was registered for tree species in soil pits and in mounds of uprooted trees in stands that were either heavily or moderately damaged. Seedling growth is expected to be better in large but shallow soil pits created by uprooted Norway spruce [Picea abies (L.) Karst.] and poorer in small but deep pits created by the hardwoods in the area, silver birch (Betula pendula Roth.) and European aspen (Populus tremula L.). The most abundant regenerating species was birch. Pits hosted larger seedling numbers than mounds, due to soil instability in mounds. Rowan (Sorbus aucuparia L.) showed significantly faster growth than the other seedling species. Norway spruce pits were preferred to pits of other species by both birch and spruce seedlings. Black alder [Alnus glutinosa (L.) J. Gaertn.] did not show a preference for pits of a certain species of uprooted tree. Both spruce and rowan preferred hardwood mounds over spruce mounds. Storm severity also affected species composition: birch predominantly occurred on pits and mounds in heavily disturbed areas, while spruce was more abundant in the moderately damaged areas. The effects of advance regeneration and surrounding stands on seedling microsite preferences should be considered in future research and subsequent management recommendations.