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紫椴优质用材林经营技术 总被引：6，自引：0，他引：6
紫椴最佳混交树种为落叶松，混交方式为行间混交。紫椴幼树越冬芽保存率最适宜的郁闭度为0.5。平茬最佳季节在冬季，其萌发率为93.33%。平茬的部位是根际下部，最佳年龄为5a。 相似文献
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通过对紫椴苗木进行人工遮荫处理,进行相对照度为70%、40%、30%、10%及全日照条件下的生长及光合特性分析。结果表明:在70%光照条件下苗木的高、地径及平均单株生物量最大,1 a、2 a生苗高分别比对照区提高20.0%和22.6%;2 a生地径达到1.9 cm,与其它试验区差异显著。相对照度10%、40%、70%及全日照的苗木其光饱和点(LSP)分别为400、800、900、800μmol.m-2.s-1。净光合速率(Pn)以相对照度70%试验区为最高,最大净光合速率达到9.28μmol.m-2.s-1,与其它试验区差异明显,10%试验区净光合速率(Pn)最低,40%与全日照试验区间差异不明显。 相似文献
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研究了紫椴种子快速催芽育苗方法,旨在掌握可靠的速效催芽技术,缩短层积时间。结果表明:采用种皮外处理加低温层积的复合措施,层积时间由150d减少到120d,催芽率达76%,比单纯层积处理提高催芽率18%。 相似文献
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生长素在紫椴种子处理中的应用试验 总被引：5，自引：0，他引：5
生长素在紫椴种子处理中的应用试验王正生赵云刘福金（吉林省林业科学研究院）纪俊清（辉南森林经营局紫椴（Ｔｉｌｉａａｍｕｒｅｎｓｉｓ）是我国珍贵的阔叶用材树种之一。材质优良，用途广泛，是制造上等胶合板的主要原材料。但就育苗而言，打破种子休眠是一难关。我们... 相似文献
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核桃楸紫椴不同造林密度的试验研究 总被引：2，自引：0，他引：2
通过１０年６种密度造林试验研究结果表明，核桃楸和紫椴的初植密度均为１．５ｍ×１．５ｍ为最佳。造林后１０年其胸径、树高、蓄积量均高于其它密度；成活率、保存率高；自然整枝好，干冠结构合理。 相似文献
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季节性冻融对亚高山冷杉林土壤微生物数量的影响 总被引：1，自引：0，他引：1
以川西亚高山地区分布范围最广和面积最大的冷杉林为研究对象,采用对照处理试验和动态采样分析相结合的研究方法,研究冻融事件对高寒森林土壤微生物数量的影响。结果表明:经过一个季节性冻融后,土壤细菌和放线菌数量显著降低,真菌数量明显增加。在自然环境梯度下,土壤细菌和真菌数量随海拔降低基本呈持续升高的变化趋势,放线菌数量则随海拔的降低而降低。腐殖质层(AL)、淀积层(BL)和母质层(CL)的微生物数量呈现不同的变化规律,海拔3298m的AL,CL土层细菌数量分别比3582m的AL,CL增加4.2%和7.0%,BL土层细菌数量降低了0.6%;海拔3023mAL,BL和CL土层细菌数量分别比3298m的相应土层增加11.5%,3.5%和2.1%。真菌数量在海拔3298m的AL,BL和CL分别比3582m的AL,BL和CL土层增加10.5%,10.3%和16.4%;3023m的AL,BL和CL分别比3298m的相应土层增加2.4%,1.7%和3.5%。放线菌数量在海拔3298m的AL土层比3582m的增加0.7%,BL和CL土层分别降低5.9%和13.9%;3023m的AL和BL土层分别比3298m增加5.2%和5.2%,CL土层降低12.4%。上述结果和室内模拟试验基本一致。同时,季节性冻融作用循环后,土壤真菌与细菌比值有所升高,这说明不同的微生物类群对季节性冻融循环的响应存在很大的差异,这种差异可能是季节性冻土区生态系统维持的重要生态学机制。 相似文献
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桉树害虫油桐尺蛾林间防治试验 总被引：2，自引：1，他引：1
对桉树害虫油桐尺蛾幼虫进行林间药剂防治试验,结果表明:使用单剂生物药剂0.6%阿维菌素水剂4 000倍液、16 000 IU.mg-1苏云金杆菌粉剂1 000倍液喷雾防治幼虫,10 d后的防治效果达89%~97%;使用混合化学药剂A3B3C3、A2B2C3和A1B3C3这3种组合喷雾防治油桐尺蛾幼虫,7 d后的防治效果达84%以上;使用混合生物药剂a1b1c2、a1b3c3和a1b1c1这3种组合喷雾防治油桐尺蛾幼虫,10 d后的防治效果达80%~96%;使用烟雾剂柴油5 kg+20%氰戊菊酯乳油0.375 kg、柴油5 kg+20%氰戊菊酯乳油0.25 kg、柴油5 kg+20%氰戊菊酯乳油0.125 kg喷雾防治幼虫,7 d后的防治效果达89%以上。 相似文献
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The cardiovascular activity of the aqueous fraction of the hydroalcoholic extract of Sida cordifolia leaves (AFSC) was evaluated. In normotensive non-anaesthetized rats was observed that AFSC (5, 10, 20, 30 and 40 mg/kg, i.v.) induced hypotension (6 +/- 2%; 8 +/- 2%; 11 +/- 2%; 19 +/- 3% and 33 +/- 3%, respectively) and bradycardia (0.3 +/- 3%; 13 +/- 4%; 38 +/- 6%; 64 +/- 7% and 80 +/- 5%, respectively). Hypotensive response was completely abolished after atropine (2 mg/kg; i.v.) but potentialized after hexamethonium (20 mg/kg; i.v.) (12 +/- 2%; 21 +/- 5%; 28 +/- 3%; 32 +/- 2% and 32 +/- 3%, respectively), while bradycardic response was completely abolished after atropine (2 mg/kg; i.v.) and attenuated with hexamethonium (20 mg/kg; i.v.) (1 +/- 0.3%; 5 +/- 1%; 7 +/- 1%; 7 +/- 1% and 10 +/- 1%, respectively). In hexamethonium treated rats, L-NAME significantly attenuated the hypotensive response (9 +/- 2%; 14 +/- 1%; 16 +/- 1%; 16 +/- 2% and 22 +/- 3%, respectively). In normotensive anaesthetized and vagotomized rats, hypotensive and bradycardic responses were significantly attenuated (0.5 +/- 0.2%; 1 +/- 0.4%; 3 +/- 0.6%; 4 +/- 0.8% and 6 +/- 1%, respectively, n = 6, and 7 +/- 2%; 12 +/- 5%; 15 +/- 2%, 17 +/- 2% and 25 +/- 3%, respectively). The anaesthesia with sodium thiopental did not affect the AFSC-induced responses when compared with those induced in non-anaesthetized rats (data not showed). In conclusion, the results obtained so far show that AFSC produce hypotension and bradycardia, mainly due to a direct stimulation of the endothelial vascular muscarinic receptor and indirect cardiac muscarinic activation, respectively. 相似文献
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利用高效液相色谱（HPI,C）法首次定量分析了木瓜（Chaenomeles sinensis）鲜花瓣中花青素3,5-二葡萄糖苷（Cya—nidin3,5-di-O-glucoside,Cy3G5G）、天竺葵色素3,5一二葡萄糖苷（Pelargonidin3,5-di—O-glucoside,Pg3GSG）、花青素3-半乳糖苷（Cyanidin3-O—galactoside,Cy3Ga）、花青素3-葡萄糖苷（Cyanidin 3-O--glucoside,Cy 3G）、芍药色素3一葡萄糖苷（Peonidin3-O-glucoside,Pn3G）、飞燕草素（Delphinidin,Dp）、花青素（Cyanldin,Cy）、芍药色素（Pconidin,Pn）和锦葵色素（Malvidin,Mv）等9种色素。其中Cy3Ga、Cy3G、Dp和色素19（保留时间13．975min）是木瓜鲜花瓣中4种重要色素,其相对含量均超过检测到色素总合量的10％,分别占检测到色素总含量的17．43％、16．63％、10．27％和23．67％,鲜叶片中买际含量分别为0．3mg／g、0．314mg／g、0．12mg／g和0．427mg／g。其它23种色素的结构和含量需要进一步分析。 相似文献
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沙枣(Elaeagnus angustifolia)也叫银柳、香柳、桂香柳,与沙棘同属胡颓子科,常绿灌木,主产于西北地区,分布在新疆、甘肃、青海、内蒙古西部等与沙漠接壤的典型大漠干旱或戈壁滩上.其树皮、果实和花均可用于治疗风寒咳嗽、痢疾腹泻等疾病(江苏新医学院中药大辞典编写组,1977). 相似文献
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Degraded Aravalli hills in western India require rehabilitation through resource conservation and afforestation for meeting the biomass needs of resource-poor tribes of the region. Rainwater harvesting treatments i.e., control, Contour trench (CT), Gradonie (G), Box trench (BT) and V-ditch (VD) were prepared in <10%, 10–20% and >20% slopes categories and Dendrocalamus strictus L. seedlings were planted in August 2005 with a view to conserve soil and water and increase the productivity of the hills. Soil water content (SWC), survival and height of D. strictus plants were highest (P < 0.05) in <10% slope and all these variables decreased with increase in slope. SWC increased by 27.45% and 25.68% in <10% and >20% slopes, respectively than in 10–20% slope. From lowest in control SWC increased by 11.95%, 20.21%, 17.61% and 11.49% in CT, G, BT and VD treatments, respectively. Growth variables were highest in VD plots but the increase in shoot number was highest (2.9-fold) in CT plots. Increase in effects of rainwater harvesting with time indicated by a change in production pattern from highest (P < 0.05) fresh and dry herbage in <10% slope in 2005 to 10–20% slope (24.66% and 26.09%) in 2006 and >20% slope (42.42% and 48.35%, respectively) in 2007. The increase in herbage was 1.17–2.40-fold in fresh and 1.20–2.52-fold in dry herbage over control. Highest (P < 0.01) production was in V-ditch plots. The treatments order for herbage production was C < CT < G < BT < VD. But the production was highest in BT in <10% and in V-ditch plots in 10–20 and >20% slopes. Conclusively, soil water status is affected by natural slope, stony soil surface and rainwater harvesting structures influencing seedling growth and herbage production. Box trench and V-ditch enhanced surface soil water facilitating herbage growth, whereas contour trench facilitated deep soil water storage, which was made available to the plants after monsoon. Thus rainwater harvesting practices enhanced vegetation cover and productivity of the degraded hills and can be replicated to conserve soil resource and increase biomass for rural poor of the region. 相似文献
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We studied physiological (gas exchange and stomatal aperture) and morphological (individual leaf area and stomatal density) responses in leaves of five-year-old olive plants (Olea europaea L. cvs. Frantoio and Moraiolo) exposed to filtered air containing < 3 ppb O(3) or 100 ppb O(3) for 5 h day(-1) for 120 days in fumigation chambers. After 100 days of treatment, leaf drop and development of necrotic spots were observed in O(3)-fumigated plants of Moraiolo but not of Frantoio. Significant reductions in photosynthetic activity (57%) and stomatal conductance (69%) were detected in O(3)-fumigated plants of Frantoio compared with control plants. In O(3)-fumigated plants of Moraiolo, the decrease in photosynthetic activity (17%) was not statistically significant, but a significant reduction in stomatal conductance (40%) was observed. In both cultivars, leaves that developed after exposure to O(3) showed decreased stomatal aperture (63.6 and 54.8% with respect to the Frantoio and Moraiolo controls, respectively) and one-sided leaf area, and increased stomatal density compared with control leaves. Actual transpiring stomatal surface decreased substantially in both Frantoio (59.8%) and Moraiolo (56.3%) in response to O(3) treatment. Relative transpiring stomatal surface (RTSS) in Frantoio decreased from 0.54 (control) to 0.27% (O(3) treated) of total leaf surface. The corresponding values for Moraiolo were 0.79 and 0.42%. However, because the RTSS of Moraiolo leaves in the O(3) treatment was 0.42 versus 0.27% in Frantoio, the potential uptake of O(3) was higher for Moraiolo plants than for Frantoio plants. The large O(3)-induced reduction in transpiring stomatal surface in both cultivars could have significant effects on olive productivity in the Mediterranean area, where high O(3) concentrations persist for long periods during the year. 相似文献
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银杏品种耐盐能力的研究 总被引：10，自引：0，他引：10
我国沿海是一个自然资源宝库 ,土地面积大 ,发展林业的潜力很大。要在这些地区建立和培育各种不同功能的人工林 (防护林、水土保持林、风景林及速生丰产林等 ) ,关键在于选择适宜于该立地条件生长的耐盐树种。近年来开展植物抗盐生理的研究已取得明显的进展 ,在植物耐盐机理、耐盐细胞系的培育、渗透调节基因的转移、野生植物抗盐基因的利用、盐生植物的开发以及利用生长调节剂来提高植物的耐盐性等方面获得了可喜的成果 (Crameretal.,1 986;刘友良等 ,1 987;John ,1 988;Gorham ,1 985 ;赵可夫等 ,1 989;沈惠娟 ,1 993)。但是对植物耐盐… 相似文献