共查询到20条相似文献，搜索用时 171 毫秒
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对山茶花品种六角红在不同配比基质上进行扦插试验,发现插穗在不同配比基质上的成活率、生根数和根长均存在极显著差异。方差分析结果表明:1)插穗在2/3黄心土+1/3腐熟松针土配比基质上的成活率最高,达92%;生根数最多,为7.20;根长最长,达10.13 cm;2/3黄心土+1/3腐熟松最适宜用于山茶花扦插。2)1/3黄心土+1/3河沙+1/3腐熟松针土也可以作为扦插基质,插穗的成活率达到84.33%。3)插穗在1/2黄心土+1/2河沙上的成活率也达80%,但生根数较少,根系不长。4)插穗在1/2黄心土+1/2草木灰和1/3黄心土+1/3草木灰+1/3河沙这2种配比基质上成活率都很低,并且生根数少,根系生长慢,不适合用作扦插基质。
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黧蒴等树种在3种人工松林中的生长量和生物量比较 总被引：1，自引：0，他引：1
对南亚热带3种人工松林中黧蒴、红桂木、灰木莲和竹节树4个树种的生长量和生物量进行了试验分析,结果显示,4个树种生长量在不同林分有很大差异:其中,黧蒴在3种林分中的生长量排序为湿地松林 > 加勒比松林1 > 加勒比松2;红桂木在加勒比松林2和湿地松林中无显著差异,均高于加勒比松林1;灰木莲和竹节树在湿地松林中最高,2个加勒比松林无明显差异。生物量排序与生长量排序相同。同一林分不同树种的生长量存在明显差异,树高和冠幅生长排序为灰木莲 > 黧蒴 > 红桂木 > 竹节树,地径为灰木莲 > 竹节树 > 红桂木 > 黧蒴;总生物量年均增长量排序为竹节树 > 灰木莲 > 黧蒴 > 红桂木。
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南方雨雪冰冻造成林业重大损失的原因分析及预防对策建议——在全国政协第十一届一次会议上的书面发言 总被引：3，自引：0，他引：3
2008年1月中旬以来,受极端天气影响,我国大部分地区遭受了特大雨雪冰冻灾害。这次雨雪冰冻灾害持续时间之长、影响范围之广、危害程度之强、受灾情况之重,实属历史罕见。
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在全面调查的基础上,对汕头市主要纯种草坪杂草的发生发展规律进行分析、对其危害程度进行评估,提出相应的防控措施,并进行了合理利用探讨。
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乳源木莲挥发油的化学成分及生物活性 总被引：3，自引：2，他引：1
采用水蒸气蒸馏法(SD)提取乳源木莲叶中的挥发油,经过气相色谱一质谱(GC-MS)联用技术分析挥发油成分,共分离出16个峰,通过与软件中的质谱标准谱图库比较确定出其中14种化合物,应用色谱峰面积归一法分析各成分的质量分数,含量较高的物质有:反-橙花叔醇(38.831%)、二环基丙二腈(13.892%)、δ-杜松烯(7.814%)、香叶醇(6.367%)。体外抑菌实验表明,该挥发油对大肠杆菌和金黄色葡萄球菌无抑制作用,对红酵母有一定的抑制作用。Alamarblue法测定乳源木莲的挥发油对人非小细胞肺癌(NCI-H460)的抑制作用很强,浓度为100μg/mL达到100%。
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对插条长度和部位与杨树扦插生根性状和成活率的关系进行了研究。结果表明,不同长度插穗之间成活率有显著差异,插穗长度为16 cm时,生根率最高,为95%;插穗长度为10 cm时,成活率最低,为65%。插条的不同部位对杨树扦插成活率也有显著影响,中部插穗成活率最高,为94%;稍部插穗成活率最低,为63%。
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六盘山叠叠沟小流域土壤稳渗速率及其影响因子 总被引：5，自引：0，他引：5
采用小区漫流法研究叠叠沟小流域内4种典型植被下的土壤稳渗速率及其影响因子.结果表明:不同植被类型的土壤稳渗速率平均值表现为天然草地>虎榛子灌丛>沙棘灌丛>华北落叶松林地.坡向影响土壤稳渗速率表现为阴坡>半阴坡>阳坡,坡位对土壤稳渗速率的影响表现为中坡位>下坡位>上坡位,坡度对土壤稳渗速率的影响表现为中坡>陡坡>缓坡,当坡度小于25.时土壤稳渗速率随坡度增大而增大,当坡度大于25°时土壤稳渗速率随坡度增大而减小.因此,以坡度25°为分界点,找到了影响土壤稳渗速率的主导因子,并经多元逐步回归得到土壤稳渗速率与主要影响因素的分段函数. 相似文献
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Berdimohammad Agherkakli Seyed Hamidreza Sadeghi Eric Zenner 《Scandinavian Journal of Forest Research》2014,29(5):499-505
Reinforcement of skid trails with slash has been shown to reduce soil disturbances, but there have not been any studies documenting the mitigating effects following traffic of harvest equipment traffic on steep mountainous skid trails. The objective of this study was to quantify potentially mitigating effects of slash cover on soil compaction and rutting on skid trails in mountainous hardwood forests. The effects of the placement of no slash (bare soil), light density slash (7.5 kg m?2) and heavy density slash (17.5 kg m?2) in a skid trail following one, five, and nine machine passes on both gentle slopes <20% and steep slopes >20% in a downhill skidding operation by a steel-tracked skidder were studied. Bulk density and rut depth increased following harvest equipment traffic on both slope gradients. Compared to bare soils, soil bulk density was not significantly reduced by light slash density; however, soil bulk density was significantly reduced by heavy slash up to five machine passes on steep slopes. Light and heavy slash significantly reduced rut depth in both slope classes. The study revealed a high protective role of slash, particularly on steep skid trails. However, benefits of slash to mitigate soil compaction were limited to five passes, after which the slash deteriorated and only provided benefits against rutting. 相似文献
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分析不同坡向、坡位对桉树造林成活率、树高及胸径的影响。采用桉树组培苗木进行造林试
验,以1年生桉树人工林样地调查数据为研究对象,调查造林效果,记录样地坡向、坡位,并实测每
株林木的树高和胸径。结果表明,坡向或坡向与坡位二者的交互作用对桉树造林成活率、树高、胸
径的影响程度均强于坡位,其中坡向对桉树造林成活率及当年生长量的影响程度最大;不同坡向对
桉树造林成活率及当年生长量的影响极为显著,造林成活率受坡向的影响最大,不同坡位对桉树造
林成活率及当年生长量的影响不显著,坡位对造林成活率、树高、胸径的影响较小;从阳坡、半阳坡、
半阴坡、阴坡光照依次逐渐减弱,桉树造林成活率分别为90.83%、84.18%、77.34%、75.95%,平均
树高从8.59 m减小到7.57 m,平均胸径从6.26 cm 减小到5.43 cm;从阳坡到阴坡,桉树造林成活
率、平均树高、平均胸径均呈现逐渐减小的趋势,而随不同坡位的降低,其变化不明显,但均在中坡
表现出最小值。 相似文献
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[目的]为揭示陕北黄土区衰退沙棘人工林天然更新的地形适生范围。[方法]通过调查陕西省吴起县沙棘人工林大面积衰退及死亡后的天然更新状况,以68个样方的更新率、成林率及每木数据(株高、地径等)作为更新恢复能力的衡量指标,运用方差分析、回归拟合及系统聚类分析等方法,分析了沙棘更新恢复能力与各地形因子的关系。[结果](1)各坡向沙棘更新率差异显著(P=0.018),沙棘更新率均值阴坡半阴坡半阳坡阳坡,阴坡更新生长状况最好,半阴坡更新幼株数量大,存活率较高;(2)坡度对更新率无显著影响,但更新率在阴坡缓坡、极陡坡范围内出现峰值,在阳坡条件下随坡度上升而减小;(3)总体上衰退沙棘人工林天然更新的地形条件是阴坡、半阴坡;(4)坡面微地形对衰退沙棘人工林更新具有显著影响(P=0.038),缓台较好,陡坎较差。[结论]半干旱黄土区部分衰退沙棘人工林可自行完成天然更新,部分恢复困难,需人工辅助或重新栽植适合的树种。阴坡、半阴坡的衰退沙棘幼株种群生长状况较好且基本能更新成林,阳坡、半阳坡的生长状况较差且难以更新成林;阴坡坡向条件下,坡度对沙棘更新率的影响程度随着坡度上升而变小,阳坡坡向条件下坡度对更新率的影响较小。衰退沙棘人工林更新率因所处微地形不同而存在差异。处于缓台的衰退沙棘幼株种群基本能更新成林,浅沟的沙棘幼株种群与所处的原状坡面上的更新状况相似,部分能更新成林,处于陡坎的沙棘幼株种群基本不能更新成林。 相似文献
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Minna Blomqvist Maiju Kosunen Mike Starr Tuula Kantola Markus Holopainen Päivi Lyytikäinen-Saarenmaa 《European Journal of Forest Research》2018,137(5):675-691
New measures for effective monitoring and controlling of bark beetle infestations are needed as a response to intensified outbreaks caused by the climate change. Various environmental factors affect tree health and susceptibility, as well as stand predisposition to bark beetles. European spruce bark beetle Ips typographus L. abundance and outbreak frequency in Finland has significantly increased during the last decade. The ability to identify sites under a high risk of infestation would facilitate adaptation to this new situation and help target limited forest health management resources. Accordingly, our goal was to investigate the importance of various stand, soil and topographic characteristics in the assessing predisposition of Norway spruce dominated urban forest in southern Finland to I. typographus infestations. Information on the environmental factors was assessed in the field in 2014 and derived from a digital elevation model. Ips typographus infestation intensity was classified into three infestation index classes based on tree-wise symptoms of resin flow, discoloration and defoliation. Cumulative logit link models were utilized for investigating stand-level infestation probability. The best explanatory factors were aspect, slope, site type and soil texture. Models with the highest cumulative probabilities for severe infestation were linked with eastern aspect, moderate steep slope and rich site type fertility (0.72) and eastern aspect, shallow soil and rich site type fertility (0.71). Higher soil C/N ratios with east aspect and rich site type fertility was associated with an increased risk of severe infestation in a third model. The lowest risk was associated with southern and southwestern aspects, fine soil texture, moderate site fertility and gentle slopes. 相似文献
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在西江中上游肇庆市德庆三叉顶市级自然保护区,对人工次生林不同坡向的凋落物水文效应进行了研究,结果如下:(1)凋落物持水率与浸泡时间存在对数曲线关系,而凋落物吸水速率与浸泡时间呈指数函数关系;不同森林类型凋落物持水率和吸水速率随时间的动态变化规律基本相似;(2)不同坡向林分凋落物最大持水率的大小顺序为:东南坡(172.3... 相似文献
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本文对红松实生种子园建园效果进行了分析.结果表明:用3 a生容器苗做定植材料效果好,结实量较裸根苗提高59.33%;陡坡立地条件母树生长最好,缓坡次之,平地最差;建园的232个家系中树高、胸径均为正选择的家系数为89个;树高、胸径遗传增益均高于5%、10%、15%的家系数分别为41个、12个、6个.优树树高单株和家系遗传力均大于胸径遗传力,且树高和胸径单株遗传力均小于家系遗传力;露水河、八家子和敦化三地种源树高单株和家系遗传力均大于胸径遗传力,且树高和胸径单株遗传力均小于家系遗传力.露水河种源树高、胸径单株和家系遗传力均高于三地种源,树高、胸径单株遗传力分别高出20.0%和20.6%,树高、胸径家系遗传力分别高出10.64%和11.63%. 相似文献
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tion resin was studied in hydrochloric acid solution by atomic absorption spectrometry.The results show that gold can be perfectly absorbed by the resin with good selectivity,and the exchange capacity of 1g dry resin is 860 mg Au.the mol ratio between saturated resin and gold was 1.08,except bismuth,other base metals have low absorption ratio,so the resin can be used to concentrate gold from large amount of base metals.The reaction enthalpy was 17.56 kJ/(mol·K).It was shown by the Infra red spectrometry and Raman Instrumentation techniques that gold absorbed in the form of AuCl4- 相似文献