大兴安岭干旱阳坡火烧迹地更新技术研究

在大兴安岭林区的干旱阳坡火烧迹地进行了整地方式、苗木T/R比、造林季节和保苗剂应用对造林成活率影响的研究。结果表明:鱼鳞坑整地能够降低土壤温度,增加土壤含水率,进而提高樟子松苗木造林成活率;随着苗木T/R比的降低,樟子松苗木造林成活率增加;樟子松和落叶松苗木春季造林成活率均高于秋季;使用HRC保苗剂后樟子松和落叶松苗木造林成活率平均增加13.7个百分点。     

针叶树苗木质量与造林成活生长关系的研究

通过 10多年来造林工作实践 ,总结出针叶树造林有关如何利用苗木的问题。油松、樟子松造林一般采用 2年生移植苗造林 ,这将有利于提高造林成活率和幼树生长量 ;采用不合格苗造林 ,将显著降低一次性造林成活率 ;苗木在出圃前要灌足“三水”即解冻水、化冻水和起苗水 ,只有提高苗木的含水量 ,才能保证造林的成活率 ,苗木的含水率与造林的成活率呈正相关 ;在造林实践中 ,不可忽视苗木的保湿 ,应尽可能做到随起苗随运输 ,随栽植 ,缩短苗木在外裸露时间     

阿拉善地区梭梭秋季造林试验

在阿拉善左旗境内选取5个试验区,观测不同时期春季造林和秋季造林新梢生长长度、地径大小、冠幅大小及苗木成活率。结果表明:各试验区内春季造林和秋季造林苗木生长量和成活率的表现规律较一致;春季造林,苗木在进入生长季后,生长缓慢,到6月后,生长速度开始加快,但与秋季造林的苗木生长量差异显著(P0.05),秋季造林苗木生长量显著高于春季造林生长量,而且,秋季造林成活率也显著高于春季造林成活率。因此,本地区适宜秋季造林。     

针叶树苗木质量与造林成活生长关系的研究

通过１０多年来造林工作实践，总结出针叶树造林有关如何利用苗木的问题，油松、樟子松造林，这将有利于提高造林成活率和幼树生长量；采用不合格苗造林，将显著降低一次性造林成活率；苗木枯出圃前要灌足“三水”即解冻水、化冻水和起苗水，只有提高苗木的含水量，才能保证造林的成活率，苗木的含水率与造林的成活率呈正相关；在造林实践中，不可忽视苗木的保湿，应尽可能做到随起苗随运输，随栽植，缩短苗木在外裸露时间。     

东北主要造林树种苗木含水量与造林成活率关系的研究

本研究是在排除人为造林技术因素,在一些主要造林树种苗木形态指标合乎要求的基础上,着重研究苗木含水量与造林成活率的关系。试验是1988～1990年在黑龙江省方正林业局进行的,目的是探索主要造林树种红松、落叶松、红皮云杉、苗木含水量与造林成活率的关系,提出影响苗木成活率的主要水份指标,以及主要水分指标与造林成活率     

马尾松苗木切根造林试验

马尾松苗木切根造林，其一苗木采用切根蘸红泥浆溶液后上山造林，其二苗木采用切根蘸2％的复合微生物菌肥溶液后上山造林，应用2种不同方法对苗木进行处理，对造林后的苗木成活率，林木生长量进行比较。其结果表明：应用复合微生物菌肥溶液处理造林的苗木成活率，林木生长量比用红泥浆溶液处理的苗木造林成活率能提高12％，当年林木平均抽梢提高44．1％。     

提高落叶松造林成活率有关问题的探讨

落叶松人工林的造林成活率受若干因素制约,苗木质量、苗木假植以及造林时间和技术措施都直接影响造林成活率。文章分析了目前影响造林成活率的各种因素,为指导落叶松生产造林提供借鉴。     

马尾松苗木切根造林试验

马尾松苗木切根造林,其一苗木采用切根蘸红泥浆溶液后上山造林,其二苗木采用切根蘸2%的复合微生物菌肥溶液后上山造林,应用2种不同方法对苗木进行处理,对造林后的苗木成活率,林木生长量进行比较.其结果表明:应用复合微生物菌肥溶液处理造林的苗木成活率,林木生长量比用红泥浆溶液处理的苗木造林成活率能提高12%,当年林木平均抽梢提高44.1%.     

不同浸苗与晾晒时间对山杏造林成活率的影响

以达到出圃标准,且苗木径、高生长差异小的1年实生山杏苗为材料,通过5次重复,5个浸苗时间及起苗后不同晾晒时间处理的植苗造林试验,结果表明:苗木的吸水时间与造林成活率呈正相关,当苗木吸水在15~24h时,成活率可提高13.8~15.8个百分点;苗木起出后,在露天晾晒,对造林成活率影响较大,随着晾晒时间的延长,造林成活率下降的越严重。因此,造林前苗木浸泡15~24h,确保苗木本身有充足的水分,苗木在起苗、贮藏、运输及造林过程中,减少自身水分消耗,是保障造林成活率的关键。     

樟子松苗木持水量与造林成活率关系的研究

通过5个晾晒时间的试验水平对樟子松苗木进行处理,研究失水过程以及不同失水量与造林成活率的关系。结果表明,未经晾晒处理的苗木,造林成活率为86.5%;而仅经过15 min晾晒,苗木的持水量只下降了5.6%,造林成活率就降到了43.8%,经过3 h晾晒的苗木,造林成活率只有2.1%。由此可见,苗木持水量的多少是苗木成活的关键因子。樟子松苗木在晾晒60 min之内失水较快,60 min以后失水变得缓慢。     

Damage by pathogens and insects to Scots pine and lodgepole pine 25 years after reciprocal plantings in Canada and Sweden

A combined species – provenance – family experiment with Scots pine and lodgepole pine was planted in Canada and Sweden. One aim of the experiment was to evaluate the two species’ sensitivities to pathogens and insects 25 years after establishment in their non-native continents. In Canada, Scots pine had better average survival than lodgepole pine, but survival rates among trees from the best seed-lots were equal. In Canada only western gall rust infected Scots pine to some extent, and mountain pine beetles attacked and killed Scots pine more frequently than lodgepole pine. At one site in Sweden, lodgepole pine had higher survival rates than Scots pine, whether evaluated as an overall average or with data from only the best surviving seed-lots. At the other Swedish site, the species’ survival rates were equal, largely since moose damage was much more frequent on lodgepole pine than on Scots pine. Adaptation to local conditions seemed to be important in the resistance of stem breakage caused by heavy snowfalls. The exotic species generally seemed to resist the new threats, but more serious damage by mountain pine beetle on Scots pine than on lodgepole pine in Canada demonstrates possible drawbacks when using exotic species which are phylogenetically similar to native.     

Growth and survival of lodgepole pine and Scots pine after 25 years in a reciprocal transplant experiment in Canada and Sweden

Lodgepole pine is native to western North America, but it is also planted as a fast-growing alternative to Scots pine in Sweden. The production of these two species, when grown as native and as exotic species, was compared in a transcontinental two-species provenance experiment. The tests were planted in 1986 on five sites in northwestern Canada and two sites in Sweden, and included full-sib families, half-sib families, seed orchard collections and natural stand seed collections of both species. After 25 years, lodgepole pine produced 48% more volume (m³ha^?1) and had 27% higher survival than Scots pine at one Swedish site, and had similar volume production and survival at a second. In the five Canadian sites, Scots pine produced on average 22% more volume than lodgepole pine. The variation between sites was, however, large. This higher volume of Scots pine in Canada could be due to higher survival (+28%) and less frequent damage; but higher top height for lodgepole pine in Canada indicated higher potential productivity. The results indicate that an exotic species may produce more than the native species, possibly thanks to higher survival, but it is also possible to increase production with successful population selection of the native species.     

Survival and Early Development of Lodgepole Pine

The effect of site fertility, spacing and mode of regeneration on the survival and stand development of lodgepole pine, Scots pine and Norway spruce was studied in a series of experiments comprising 22 study areas in Finland. After 13-14 yrs, lodgepole pine had a mean survival of 68% in planted and 61% in seeded plots, while Norway spruce had the highest (92%) and Scots pine the second highest survival (82%). The survival of planted lodgepole pine was better the wider the spacing. Best survival was achieved on subdry and dry sites, both with planting and with direct seeding. Dominant height was not affected by spacing, but both basal area and volume at the age of 13-14 yrs were significantly higher the denser the spacing. The average difference in the value of the estimated site index H ⁵⁰ was slightly under 3 m for the superiority of lodgepole compared with Scots pine. Seeding resulted in site indices almost as high as those of lodgepole planting.     

Assessment of early survival and growth of planted Scots pine(Pinus sylvestris) seedlings under extreme continental climate conditions of northern Mongolia

Environmental factors play vital roles in successful plantation and cultivation of tree seedlings.This study focuses on problems associated with reforestation under extreme continental climatic conditions.The objectives were to assess relative seedling performance(survival and growth)with respect to plantation age,and to analyze the influence of specific climatic factors during the early stages of Scots pine(Pinus sylvestris L.)plantations.The study was carried out in reforested areas of the Tujyin Nars region of northern Mongolia on six Scots pine plantations ranging from 5 to 10 years.In each of the six plantations,five 900 m^2 permanent sample plots were established and survival rates and growth performance measured annually over 7 years.Results show high variation in survival among the plantations(p<0.001,F=29.7).Seedling survival in the first year corresponded directly to the number of dry days in May.However,survival rate appeared to stabilize after the second year.The insignificant variation of height categories throughout the observation period indicated low competition among individuals.Two linear mixed-effect models show that height and radial growth were best explained by relative air humidity,which we consider to be a reliable indicator of site-specific water availability.Insufficient amounts and uneven distribution of rainfall pose a major threat during the first year of plantation establishment.Humidity and water availability are decisive factors for a successful seedling plantation.This highlights the impact of drought on forest plantations in northern Mongolia and the importance of developing climate resilient reforestation strategies.     

天然樟子松林幼树更新格局及其影响因子分析

以呼伦贝尔沙地红花尔基镇樟子松天然林幼树为研究对象,对100m×100m的樟子松纯林样地进行全面调查,并采用空间点格局分析的方法对林内幼树更新格局及其主要影响因子进行分析。研究结果表明,林分中樟子松幼树在较大尺度内(40m)呈显著的聚集分布状态,大树在较小尺度内(4m)呈显著聚集状态,而蚁穴则在所有尺度内呈随机分布状态。对同种的樟子松幼树和大树而言,两者的关系在不考虑其它影响因子(蚁穴)的情况下,总体上不存在显著的作用关系;而在考虑蚁穴作用的情况下在0~2m尺度上表现为抑制作用,3~4m尺度上表现为促进作用,但两者均不显著。对樟子松幼树和蚁穴而言,两者的关系在不考虑其它影响因子(樟子松大树)的情况下,在较小尺度上对樟子松幼树产生了一定的抑制作用;在考虑樟子松大树作用的情况下,不显著的抑制作用进一步缩小为0~2m尺度上,而在3~4m的尺度上则表现为不显著的促进作用,其影响略强于樟子松大树。结合幼树成活率和保存率的分析结果,可以得出樟子松天然林幼树保存率低,很大程度上取决于气候因子特别是干旱带来的水分亏缺的影响。     

Seedling shoot,needle and bud development in three provenances of Pinus sylvestris and Pinus contorta cultivated in northern Sweden

The patterns of current‐year shoot, needle and terminal bud elongation in seedlings of three Scots pine (Pinus sylvestris L.) and three lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) provenances were compared during the third and fourth growing seasons after planting. Lodgepole pine produced longer shoots and buds than did Scots pine, mainly because lodgepole pine formed more stem units and elongated at a faster rate. Stem unit length and the duration of shoot and bud elongation differed relatively little between species and provenances. Lammas or polycyclic growth occurred in some lodgepole pine provenances, but not in any Scots pine provenance, and was associated with enhanced shoot elongation. Needle elongation commenced earlier, proceeded at a faster rate, and was greater in lodgepole pine than in Scots pine, but ceased about the same time in all species and provenances. The heat sum required to attain 50% of final length was lower for shoots and needles in lodgepole pine than in Scots pine, and for shoots in northern provenances than in southern ones. Mitotic activity in the apical meristem of the terminal bud, which occurred less than one week after the seedlings were free from snow, started and ceased about the same time in each species, but was higher in lodgepole pine than in Scots pine early in the shoot elongation period.     

Structure and abundance of arachnid communities in Scots and lodgepole pine plantations

Between April and September 1994, six plots within Aberfoyle Forest in Scotland, three of Scots (Pinus sylvestris) and three of lodgepole pine (Pinus contorta), were surveyed for spiders and harvestmen, as these are predators of several forest invertebrate pests.A total of 64 species of spider were trapped in Scots and lodgepole pine; 56 in Scots pine and 32 in Lodgepole pine. The most abundant spiders, both in Scots and Lodgepole pine, were Linyphiidae.Scots pine plots were floristically more diverse and structurally more complex than lodgepole pine plots. More species of spiders and harvestmen (midsummer only) were found at ground level in Scots pine than lodgepole pine plots. More species and a greater numbers of spiders were found in the canopy of Scots pine than in that of lodgepole pine. However, no differences in the abundance of harvestmen were found between the canopies of Scots and lodgepole pine. Spider species diversity was greatest in Scots pine.     

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.     

A preliminary study on the genetic structure of Northern European pinus sylvestris L. by means of neutral nuclear microsatellite markers

This paper aimed to investigate the genetic structure (GS) of Scots pine in the northern area of its distribution range by means of seven neutral nuclear microsatellite markers. In particular, the postglacial recolonization of these areas and possible different adaptation patterns in distinct refugia were studied. The GS and diversity were assessed with seven pairs of neutral nuclear microsatellite primers. A high genetic diversity was found in the Scots pine material tested, along with a shallow GS. This pattern is typical for recolonized areas and species with large population sizes, which are connected by pollen-mediated gene flow. A STRUCTURE analysis found two genetic groups to be the most likely, one south-eastern and one north-western group that meet in Fennoscandia. This indicates that Scots pine recolonization of Fennoscandia might have taken place from two different directions (south-west and north-east). Scots pine that recolonized the area originated in at least two different refugia during the last glacial maximum. The glacial survival in distinct refugia can have led to different adaptation patterns and growth optima in the different groups as reflected in the formation of latewood content, where lineage was a significant influencing factor.     

Susceptibility of four conifer species to Gremmeniella abietina

G. abietina causes severe dieback in pole-stage stands of Scots pine in Britain. The susceptibility of ll provenances of Scots pine and of three other conifer species was tested by inoculations. Significant differences in susceptibility were found amongst Scots pine provenances, with those originating from a native Scottish pinewood at Loch Maree showing the highest levels of disease. Corsican pine was shown to be the most susceptible species tested although sporulation was greatest on Scots pine. Norway spruce was also shown to be susceptible when inoculated late in the growing season. Infection in lodgepole pine was negligible. High levels of β-phellandrene were tentatively linked with resistance among trees in a single stand of Scots pine.