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紫竹别名黑竹,为优良的观赏竹种,竹材较坚韧,宜作钓鱼竿、手杖等工艺品及箫、笛、胡琴等乐器制品。产地竹材价格高达140—160元/kg,集约经营的林分每亩可年产竹材800~1000kg,产值1000~1500元。为提高紫竹林的生产水平,我们在生产中采用施不同肥料,从中找出施肥增产的原因、方法、途径以及施肥增产的作用规律,为紫竹丰产提供理论依据。 相似文献
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通过对云南省海子坪省级自然保护区境内分布的大面积天然水竹林进行调查,以竹类无性系种群生态学理论为基础,运用分析软件进行分析研究,结果表明:(1)海子坪水竹无性系种群年龄结构的总体趋势是随着分株年龄的增大,在整个种群中所占的分株比例逐渐减少;(2)海子坪天然水竹无性系种群出现低矮化和纤细化的衰退现象;(3)根据地径、胸径与分株高度的规律拟舍出天然水竹无性系种群分株高度的一元线性方程分别为H=0.9631+1.7493X地、H=1.5007+1.6588X胸。 相似文献
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为了解大熊猫种群活动是否会对巴山木竹无性系种群产生影响,在佛坪自然保护区内分别设立了干扰样地和非干扰样地,探讨了不同干扰程度下巴山木竹无性系种群的形态可塑性。结果表明:大熊猫干扰样地巴山木竹无性系种群出现退化趋势,除分株数目与最长分枝外,其余各形态指标均显著小于非干扰样地。同时,线性回归结果显示,大熊猫取食强度与巴山木竹发笋产量之间具有显著的相关性,巴山木竹发笋时期,大熊猫种群对巴山木竹无性系种群表现出明显的依赖性。 相似文献
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从竹类无性系种群增长及结构动态、无性系生长格局、形态可塑性、生理整合作用和生态对策等方面,对竹类无性系种群生态学的研究现状进行了分析和总结,提出以生态高效整合理论及技术为核心的竹类无性系种群生态学研究方向,在21世纪竹林资源培育与利用实践中具有广阔的应用前景。 相似文献
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冷箭竹更新幼龄无性系种群结构的研究 总被引:9,自引:1,他引:8
本文分析了卧龙自然保护区冷箭竹更新幼龄无性系种群的龄级结构、径级结构和高度结构及其与生境条件的关系。结果表明;冷箭竹更新幼龄无性系种群为一增长种群;径级处于小径阶区域,主要位于0.00-0.15cm之间;高度结构呈倒“丁”字型,随着高度级的增加,植株数量表现出递降趋势。同时,不同林分类型和海拔高度内冷箭竹的种群结构具有不同的分布格局,这与微生境、林分郁闭度、群落结构和野生动物影响密切相关。 相似文献
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General decline of understory cover can result from increased abundance of and foraging pressure by deer.But population size and degree of aggregation can increase for unpalatable understory plants that escape foraging pressure.Clonal reproduction can enable unpalatable plant species to increase their population sizes while trending toward spatially aggregated distributions.However,the details of the relationship between clonal reproduction in unpalatable plants and their dynamics under intensive deer herbivory are not clear.We compared the population structures and spatial patterns of two coexisting unpalatable plant species,Arisaema ovale(with clonal reproduction)and A.peninsulae(without clonal reproduction)in a riparian forest intensively grazed by Sika deer,and examined the null hypothesis that the extent of spatial aggregation and local population size would not differ between the clonal and non-clonal Arisaema species.In a 0.36-ha plot,A.ovale had a larger population size(1087 individuals)with a higher abundance ratio of small plants(p<0.01)than A.peninsulae(84 individuals).Analyses of spatial point processes showed that both populations were spatially aggregated(p<0.05).The spatial aggregation of A.peninsulae,however,became weaker than that of A.ovale,when we excluded one dense patch originating from irregular seed dispersion.These results,excluding the aggregated distribution observed in A.peninsulae,suggested a substantial contribution of clonal reproduction to the expansion of the local A.ovale population following intensive grazing by Sika deer. 相似文献
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Further studies on differing susceptibilities of Pinus nigra clones to Scleroderris lagerbergii. In a seed orchard 14 clones of Austrian black pine (Pinus nigra ssp. nigra) showed significant differences of susceptibility to Scleroderris lagerbergii. Significant clonal differences existed also in buffering capacity of homogenized bark tissue of one-year shoots. Less susceptible clones had a higher buffering capacity. 相似文献
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阐述了企业物资购销合同管理应注意的问题,指出要增强法律意识、建立健全物资供销合同管理体系,要依法签订物资购销合同,要把好签约关、审批关、定金关、验收关和付款关。 相似文献
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无性系林业:工业人工林世界潮流新营林体系 总被引:14,自引:2,他引:12
随着工业人工林的发展,为取得最大的经济效益和满足工业生产对林产品质和量的新要求,世界兴起了以人工选育的无性系为造林材料的无性系林业。文章介绍了无性系林业的性质、国内外研究现状、发展趋势和我国应采取的对策等。 相似文献
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We have studied male flower production and relative illumination in clonal sugi (Cryptomeria japonica) forests planted at densities of 1,500/ha, 3,000/ha, and 5,000/ha, to clarify the effects of forest management on male flower
production. Both the relative illumination and male flower production decrease as the stand density increases. The lowest
position at which male flowers are formed decreases as the density of the stand decreases. High thinning intensity promotes
male flower production and light pruning is ineffective to reduce male flower production. Therefore, traditional management
methods used in sugi forests (i.e. planting at high density, frequent light thinning, intensive pruning and short rotation) are ideal strategies for limiting
male flower production. 相似文献
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在对我国园林绿化苗木产业发展进行现状总结的基础上,重点分析了绿化苗木生产问题、销售问题和体制机制问题,从生产供应体系、科技研发、标准建设、社会服务体系和销售流通体系5个方面提出了我国园林绿化苗木产业的发展策略。 相似文献