共查询到18条相似文献,搜索用时 156 毫秒
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于宁乡、湘乡、道县选择18、19、21年生的马尾松人工中龄林,对其间伐与施肥效应进行研究,结果表明:间伐与施肥1年后,缩短了轮伐期1~4年。宁乡试验点胸径平均增长了2.26 cm,较对照的增长量大1.89 cm,平均增长率达15.44%;单株材积平均增长了0.023 2 m3,较对照的增长量大0.014 8 m3,平均增长率达19.72%;单位面积材积平均增长了0.267 5 m3/667 m2,较对照的增长量大0.256 1 m3/667 m2,平均增长率达2.82%;胸径增长量和单株材积增长量均以保留密度为50株/667 m2的处理最大,而单位面积材积增长量则以保留密度为70株/667 m2的处理最大。湘乡试验点的单株材积增长显著,平均增长率达62.65%;道县试验点的单位面积材积增长显著,平均增长率为5.29%。差异显著性检验结果是:密度、施肥方式和区组间的胸径增长量均存在极显著差异,同时,密度×施肥方式和施肥方式×区组对胸径增长的交互作用也达到了极显著;单株材积增长量在密度间的差异达到了极显著;单位面积材积增长量在施肥方式间的差异极显著。 相似文献
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收集适性区内遗存的艾纳香品种进行生长及艾粉提取率试验,结果表明:艾纳香人工种植以第2-3年产量最高;栽培驯化会促进艾叶中艾粉的积累和龙脑含量的提高;艾纳香的生产种植首选大艾,其次为马其艾。 相似文献
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油茶芽苗砧嫁接苗田间移栽试验 总被引:2,自引:0,他引:2
以怀化市林业科学研究所油茶采穗圃的湘林1号、104号和长林3号、4号等20多个油茶优良无性系为试材,对油茶芽苗砧嫁接苗进行田间移栽试验。试验结果表明:短期移栽密度以222~333株/m2,株行距3 cm×15 cm、3 cm×12 cm和3 cm×10 cm,产苗量7~10万株/667 m2的密度最合适;移栽天气以毛毛细雨天和阴天最佳,其次是晴天;最适砧木粗度为0.31~0.45 cm;拱膜密封嫁接苗保温保湿天数以90~95 d,且第1次密封时间以40 d左右为好。 相似文献
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对单瓣茉莉花进行容器嫩枝扦插育苗试验,结果表明:在6月下旬进行带叶嫩枝扦插,摆放在室内向阳窗台,插穗经过清水浸泡,在插穗上扣瓶密封,利用植物自身营养,完全能达到离体培养的效果,生根率为100%,分株移栽成活率达90%。 相似文献
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大叶桂樱无性系扦插繁殖 总被引:1,自引:0,他引:1
对大叶桂樱(Laurocerasus zippeliana)无性系采穗圃嫩枝进行扦插繁殖生根试验,结果表明:大叶桂樱无性系嫩枝扦插生根兼有皮部生根和愈伤组织生根,参试的10个无性系中有2个无性系同时含有2种生根类型,有8个无性系以皮部生根类型为主,占参试无性系的80%。大叶桂樱无性系嫩枝生根能力既根系效果指数REI与生根率之间成显著的正相关关系;在遮荫降温、农膜保湿及自然温度条件下,以6月、9月和10月上旬大叶桂樱嫩枝扦插生根率最高。 相似文献
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对大叶桂樱(Laurocerasus zippeliana)无性系采穗圃嫩枝进行扦插繁殖生根试验,结果表明:大叶桂樱无性系嫩枝扦插生根兼有皮部生根和愈伤组织生根,参试的10个无性系中有2个无性系同时含有2种生根类型,有8个无性系以皮部生根类型为主,占参试无性系的80%。大叶桂樱无性系嫩枝生根能力既根系效果指数REI与生根率之间成显著的正相关关系;在遮荫降温、农膜保湿及自然温度条件下,以6月、9月和10月上旬大叶桂樱嫩枝扦插生根率最高。 相似文献
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选择12和14地位指数的2种立地的林分,分别设置6种和5种保留密度,对间伐4年后的23年生马尾松天然次生林林下植物多样性进行研究。结果表明:马尾松天然次生林林下植物种数随着林分保留密度的增大,12和14地位指数的林分均表现为由逐渐增加至一个峰值后逐渐减少;适宜的保留密度有利于提高林下植物的多样性,12和14地位指数林分的植物多样性分别以保留密度130株/667 m2和100株/667 m2的样地为最优;随着林分密度与冠层郁闭度的增大,林下植物类型有由阳性植物为主向中性与荫性变化的趋势,而形成阳性、中性及荫性共存的多态性植物群落;适宜的保留密度有利于提高林下植物的生物量和植被总盖度,12和14地位指数林分的林下植物生物量和植被总盖度分别以保留密度130株/667 m2和90株/667 m2的样地为最佳;2种地位指数不同保留密度林分的林下枯落物自然风干重、枯落物层厚及腐殖质层厚差异均不显著,而林下地被物鲜重和植被总盖度则均表现为差异极显著。 相似文献
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3,4',5-Trihydroxy-3',7-dimethoxyflavanone was isolated from the ligroin extract of the leaves of Blumea balsamifera, while the acetone extract yielded 3',4',5-trihydroxy-7-methoxyflavanone and a new biflavonoid identifed as 3-O-7'-biluteolin (1). The isolation of 1 is significant since a biflavonoid with a C-O-C linkage of the type [I-3-O-II-7] has not been previously reported from a plant. 相似文献
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湘南丘陵地桉树纸浆林栽培模式研究 总被引:1,自引:0,他引:1
桉树已成为湖南湘南地区栽培的主要纸浆林树种。通过对桉树肥料、整地、密度等分析,得出湘南地区桉树集约经营的主要栽培模式:使用较耐寒的桉树品种(赤桉、邓恩桉、柳桉)的优良无性系或种源,15-20cm的容器苗,整地方式为人工带垦、中穴或机耕,每穴施放430g磷肥作为底肥,其间追施尿素65g、氯化钾肥25g,或追加氯化钾50g,或追加尿素130g,造林密度为1667-2505株/hm^2,轮伐期6-8年,栽植后要连续抚育3年,每年1-2次,主要是松土、扩穴、培蔸、施肥、控制杂草、防治病虫害。 相似文献
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通过正交试验设计研究直杆大叶相思良种采穗圃母株不同定植密度、不同截干高度及施用不同种类的基肥对母株产穗量的影响,结果表明:直杆大叶相思母株定植株行距20 cm×20 cm,配合母株距根茎部位20 cm处截干,结合每667 m2施用70 kg硫酸钾复合肥作基肥(A3B3C2)组合产穗量最高。 相似文献
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Poplars are one of the woody plants that are very sensitive to water stress, which may reduce the productivity of fast-growing plantations. Poplars can exhibit several drought tolerance strategies that may impact productivity differently. Trees from two improved hybrids, Populus balsamifera?×?Populus trichocarpa Torr. & Gray (clone B?×?T) and P. balsamifera?×?Populus maximowiczii A. Henry (clone B?×?M), having P. balsamifera L. as a parent and trees from native and unimproved P. balsamifera were subjected to a 1-month drying cycle in a growth chamber and then rewatered. The unimproved and native B clone maintained higher stomatal conductance (g(s)) than the hybrids, and high photosynthetic activity and transpiration, even when soil water content was nearly zero. As a result, both instantaneous water use efficiency (WUE(i)) and leaf carbon isotope composition (δ(13)C) indicated that this clone was less affected by drought than both hybrids at maximal drought stress. However, this clone shed its leaves when the drought threshold was exceeded, which implied a greater loss of productivity. The B?×?M hybrid showed a relatively conservative response to water stress, with the greatest decrease in transpiring versus absorbing surface (total leaf area to root biomass ratio). This clone was also the only one to develop new leaves after rewatering, and its total biomass production was not significantly decreased by drought. Among the two hybrids, clone B?×?T was the most vigorous, with the greatest transpiration (E(i)) and net CO(2) assimilation (A) rates, allowing for high biomass production. However, it had a more risky strategy under drought conditions by keeping its stomata open and high E(i) rates under moderate drought, resulting in a lower recovery rate after rewatering. The opposite drought response strategies of the two hybrids were reflected by clone B?×?T having lower WUE(i) values than clone B?×?M at maximal drought, with a very low Ψ(min) value of -3.2 MPa, despite closed stomata and stopped photosynthetic activity. Positive linear relationships between A and g(s) for the three hybrids indicated strong stomatal control of photosynthesis. Moreover, the three poplar clones showed anisohydric behaviour for stomatal control and their use under long-term drought should be of interest, especially the B?×?M clone. 相似文献
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