共查询到19条相似文献,搜索用时 171 毫秒
1.
采集清流县大丰山长苞铁杉当年生、自然掉落的饱满种子进行育苗试验.结果表明:长苞铁杉育苗在50%日照条件下种子萌发率和幼苗成活率最高,幼株生物量最高,幼株生长最快,整个生命期生长最好;菌根接种对提高长苞铁杉种子萌发率没有明显的作用,但是菌根土育苗能显著提高幼苗的成活率,能极大提高幼苗生长量. 相似文献
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本文研究了上层木清除和凋落物清除等措施对长苞铁杉幼苗更新的影响,结果表明:人工形成的中等大小以上的林中空地和凋落物清除有利于长苞铁杉幼苗的生长和存活。 相似文献
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长苞铁杉群落结构特征研究 总被引:4,自引:0,他引:4
长苞铁杉属于珍稀濒危植物,被列为国家Ⅲ级保护植物。在样地调查材料的基础上,对福建省天宝岩自然保护区珍稀植物长苞铁杉群落结构、群落数量特征、种群动态进行了深入分析与研究。并对长苞铁杉濒危机制及保护措施进行了探讨,为长苞铁杉林的保护提供了理论依据。 相似文献
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2004~2006年研究了在不同光照下长苞铁杉幼苗生物量、营养元素在幼苗器官中的含量和分布。结果表明:50%全照条件下,幼苗根、茎、叶及总生物量最高,是较为合适的光照强度;在生物量累积方面,幼苗根、茎和叶中,受光照强度的变化影响最大的器官是根,影响最小的器官是茎。光照强度对长苞铁杉幼苗根、茎、叶中N、P、K等主要元素的含量有显著影响,并可以影响它们在根、茎、叶的分配比例。 相似文献
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南方铁杉与长苞铁杉物理力学性质研究 总被引:1,自引:0,他引:1
本文对产于福建省武夷山市的南方铁杉和连城县的长苞铁杉进行了较系统的材性试验研究,提供了必要的该铁杉属木材的物理力学性质指标。 相似文献
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ZHU Xiaolong Research Institute of Forestry Policy Information Chinese Academy of Forestry Beijing P. R. China 《中国林业科技(英文版)》2007,6(3):66-71
Effects of three gaps which are large (118 m^2), medium (86 m^2) and small (20 m^2), respectively, and under canopy of Tsuga longibracteata forest on the seedling establishment of T. longibracteata were studied through seed burial experiments from December 2003 to January 2005 in Tianbaoyan National Nature Reserve of Fujian, China. The results showed that the area of gap had an evident effect on the seedling establishment of T. longibracteata. The seedling emergence rates of T. longibracteata in plots of large gap, medium gap, small gap and under canopy were 10%, 10%, 4% and 6%, representing an increasing trend along with the gap size increasing without a significant difference. Rain eroding and insects feeding were two main factors leading to seedling death. The larger the gap size was, the more seedlings were killed by rain erosion and the fewer seedlings were killed by insects feeding. The emergence time of seedlings was almost same in all plots while their death time was different respectively. The gap size had a significant impact on seedling survival rate. The seedling survival rate was highest in the medium gap plot (27.0%) and next to the highest in large gap plot (7.3%), and seedling in small gap plot and under canopy plot died out after one growing season. Increased light supply in gaps was favorable for the seedlings growth and survival. Increased light supply in the large gap could enhance the growth of seedling leaf and root of T. longibracteata, and the seedling in turn allocated more dry mass to root and leaf, but it has little impact on the growth of stem. This research indicates that T. longibracteata is a pioneer species and its seedling establishment need a medium or large gap (〉50 m^2). 相似文献
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对闽西邱家山长苞铁杉天然林、常绿阔叶林和杉木人工林的林冠层、林下植被层和凋落物层的持水量、土壤的蓄水能力和渗透性能进行研究 ,结果表明 :长苞铁杉天然林地上部分持水量与常绿阔叶林接近 ,分别为 2 5 8 4 2 6t·hm-2 和 2 77 2 4 2t·hm-2 ;林地土壤的稳渗值亦相近 ,分别为 6 6 8mm·min-1和 6 91mm·min-1,分别是杉木人工林土壤的 1 8倍和 1 9倍。说明了长苞铁杉天然林具有良好的水源涵养功能 相似文献
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The relative influence of seed and microsite availability in the seedling emergence and recruitment of Liaodong oak (Quercus wutaishanica), which dominates the native hardwood forest in Loess Plateau, was examined by seed sowing experiments. Experiments were
performed in 216 plots (30 × 30 cm), located in three typical stands (Pinus tabulaeformis plantation, Liaodong oak forest and grassland, 72 plots per stand). A seed augmentation experiment was performed in an oak
forest and a conifer plantation, and a seed introduction experiment was carried out in a grassland. Three main factors were
considered: seed addition, disturbance and shrub cover. The seedling number and growth in every plot were recorded continuously
over 3 years. GLM multivariate was used to analyze the relationships between seedling emergence/recruitment and the explanatory
variables in every stand. The results showed that seed addition in undisturbed or disturbed plots always caused significantly
increased seedling emergence and recruitment in oak and conifer forests. It demonstrated that the recruitment of Liaodong
oak was limited by seed and microsite availability under closed forest, and litter is one of the factors leading to microsite
limitation. However, in the grassland, no treatments improved recruitment, indicating that the grassland was not suitable
for seedling recruitment because of intense light and soil drought. In the conifer forest, more recruited seedlings, and lower
herbivory on seedling leaves, as well as thicker stem basal diameters, indicated that the P. tabulaeformis plantation was safer for Liaodong oak seedling establishment. Unexpectedly, shrub cover did not affect the recruitment of
Liaodong oak in the three stands. 相似文献
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Sandrine Godefroid Shyam Singh Phartyal Gisle Weyembergh Nico Koedam 《Forest Ecology and Management》2005,210(1-3):91-105
The relation between invasion success of Prunus serotina and type of recipient habitat was studied in a large forest in central Belgium. The major emphasis in this study was the determination of factors controlling the abundance of P. serotina in understory strata. Environmental variables measured in 34 sample plots were slope, aspect, litter depth, soil type, pH, soil compaction, soil moisture, air humidity, soil temperature and light intensity in spring and late summer. Site conditions were also expressed indirectly for 210 sample plots using Ellenberg indicator values (soil nutrients, acidity, moisture, light conditions). Plots with P. serotina had lower mean indicator values for soil moisture, reaction (pH) and nitrogen, compared to plots without P. serotina. Twenty indicator species were identified for plots in which P. serotina occurs. The species richness of the herb layer was negatively correlated with the percentage cover of black cherry in the shrub layer. The percentage cover of P. serotina saplings in different overstory types was ranked as follows: Quercus > Pinus > Fagus > logging areas. Only three variables explained significant amounts of variation in Prunus abundance: slope, light intensity at 120 cm in April and light intensity at ground level in September. We found a positive response of black cherry seedlings to light intensity between 58 and 80% of full light (April measurements at 120 cm), while saplings showed a negative response within this range. Between 21 and 47% of full light (April measurements at 120 cm), seedlings were poorly represented whereas saplings showed a quite high cover. Between 0.3 and 1.8% light (September measurements at ground level), seedlings were almost absent while saplings maintained a high abundance. The results suggest that P. serotina shows a differential response to light intensity in relation to its development stage, i.e. the species is heliophilous at the seedling stage and becomes a shade plant at the sapling stage. 相似文献
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以半年生桢楠(Phoebe zhennan)幼苗为试材,采用正交试验设计,初步研究了容器规格、肥料种类和育苗基质对桢楠容器苗的苗高、地径、根系长、全株鲜重、全株干重影响。结果表明,不同的肥料种类对幼苗的苗高、地径、全株鲜重、全株干重均有显著影响(P<0.05),而容器规格和育苗基质对容器苗的生长无显著影响。对不同因素、不同水平的各个组合处理进行分析,半年生桢楠的容器育苗最佳组合为8 cm×12 cm的容器规格,施用5%有机肥作为基肥,采用80%森林土+20%的火烧土作为育苗基质,其次是10 cm×14 cm的容器规格,施用5%有机肥作为基肥,采用100%森林土的育苗基质。 相似文献
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Mark H. Hancock Ron W. Summers Andy Amphlett Johanna Willi 《European Journal of Forest Research》2009,128(4):319-333
Techniques for encouraging natural tree regeneration are of increasing interest to managers of Scots pine Pinus sylvestris forests. We tested prescribed fire at a management scale, with deer present or excluded, as a means of increasing rates of
Scots pine forest expansion on heathland. At a semi-natural pinewood in Scotland, ten experimental blocks were established,
within range of pine seed-fall. Each block comprised four, 100 m2 plots. Two plots at each site were burnt and two fenced, allowing the effects of burning on pine regeneration to be measured
at two levels of deer abundance. We monitored pine seedlings, seed-fall, deer dung and vegetation for 5 years following treatment.
Differences in seedling detection rates between treatments were quantified using dummy seedlings, and analyses corrected accordingly.
Mean new pine seedling establishment was 9.8 times higher on burnt ground than unburnt ground (confidence intervals 3.2–30).
Differences were even more pronounced in a year of high seed-fall, and following fires with low rates of spread. Establishment
rates varied strongly between experimental blocks. Exclusion of deer increased establishment rates, but only in the first
2 years after fire. There was evidence that both seedling survival, and cumulative recruitment of older (over 12 months) seedlings,
were improved by prescribed burning. Our results support the use of prescribed fire as a tool to promote increased Scots pine
seedling establishment. This technique is likely to give strong fine-scale variation in seedling densities, and so would most
suit areas where a variable spatial pattern of regeneration is sought, for landscape or naturalness reasons.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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P. M. McEvoy J. H. McAdam M. R. Mosquera-Losada A. Rigueiro-Rodríguez 《Agroforestry Systems》2006,66(2):85-92
Forest grazing has been recognised as being a useful tool in fire-risk reduction, in addition to having the potential to preserve
or enhance forest biodiversity if managed correctly. Concern for natural regeneration of forest trees in Europe has also prompted
interest in the effects of large herbivores on seedling and sapling growth and mortality. An investigation was carried out
into sapling damage and density of natural regeneration of oak (Quercus robur) in a mature, pony-grazed, Pinus radiata forest in Galicia, NW Spain under two different grazing regimes (continuous and rotational). In all treatments significantly
more oak seedlings and saplings were recorded in areas of grass sward than areas dominated by taller ground flora species.
Damage to oak saplings was assessed from the form (height and canopy) relative to stem diameter. The height and average canopy
diameter of similar-aged saplings were found to be significantly greater in ungrazed (control) than both continuous and rotationally
grazed treatments. Height and canopy diameters of similar-aged oak were not significantly different between the two grazing
treatments. Significant differences were observed in tree form, with unbrowsed saplings having the greatest height to canopy
width ratio and those in the continuously browsed plots having the smallest. An obvious decrease in the goodness of fit (R2) of regression analyses were found in continuously grazed areas compared to rotational and control plots for both height
and canopy data. The differences in damage observed were not significantly different enough to suggest one method of grazing
over the other as being better for minimising sapling damage. Management requirements are more likely to dictate grazing regime.
Overall, stock density is likely to have a more significant effect on damage than stocking system. 相似文献
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Tree regeneration in gap-understory mosaics in a subtropical Shorea robusta(Sal) forest 总被引:1,自引:0,他引:1
《林业研究》2019,(6)
Spatial variation in tree-regeneration density is attributed to the specialization of tree species to light availability for germination and growth. Light availability,in turn, varies across the gap-understorey mosaic. Canopy gaps provide an important habitat for the regeneration of tree species that would otherwise be suppressed in the understory. In subtropical forests, there is still a knowledge-gap relating to how canopy disturbances influence tree-regeneration patterns at local scale, and if they disproportionately favor regeneration of certain species. We aim to analyze whether canopy gaps promote tree regeneration, and tree species are specialized to gaps or understory for germination and growth. We sampled vegetation in 128 plots(0.01 ha), equally distributed in gaps and below canopy, in two subtropical Shorea robusta Gaertn.(Sal) forests in Nepal, recording the number of tree seedlings and saplings in each plot. We compared the regeneration density of seedlings and saplings separately between gaps and the understorey. The mean densities of seedlings and saplings were higher in the gaps at both sites;although there was no difference in the seedling density of the majority of the species between the habitats. No species were confined to either gap or understorey at the seedling stage. We conclude that gaps are not critical for the germination of tree species in Sal forests but these are an important habitat for enabling seedlings to survive into saplings. The classification of trees into regeneration guilds mainly based on germination does not apply to the majority of tree species in subtropical Sal forests. Our results reaffirm that gap creation promotes tree regeneration by favouring seedling survival and growth and can influence forest management for conservation, as well as for plantations. 相似文献