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1.
青檀,为我国特产树种。其适应性强,在石灰岩山场生长良好,较耐旱和瘠薄,根系发达,萌蘖性强,可经营矮林作业以截取枝条。枝皮富有纤维,绵韧易剥,是制造宣纸的特需原料。一、播种育苗青檀种子具有生理休眠特性,且种子个体的休眠深度差异较大。种子催芽方法,一是将种子装入木桶内,  相似文献   

2.
The competition-density (C-D) effects for mean mass for tree, stem, branch and leaf were analyzed in Acacia auriculiformis stands. Mean tree mass-density and mean organ mass-density were well explained by the C-D equation of tree and the C-D equation of tree organ, respectively. An equation describing the relationship between mean leaf area u and density was formulated that fit the u-data well. The relationship between mean tree mass w and the ratio of each organ to mean tree mass (wo/ w) was examined. With increasing w, the stem mass ratio wS/w increased, whereas the branch mass ratio wB/w and the leaf mass ratio wL/w decreased. The yield difference between the lowest-density stand and the high-density stand became greater with stand growth. However, the yield of the mid-density stand was slightly lower than the yield of the high-density stand during the experimental period. To produce the most desirable combination of demanding individual-tree size and relative high stem yield, the mid-density is recommended as proper planting density for future management of A. auriculiformis stands.  相似文献   

3.
《技术与市场》2007,(4):26-26
自动取暖保健热宝是传统手炉的替代新产品,该产品不用电可持续供热,它使用方便,价格低廉,是人们冬季的首选暖手用品,也是野外作业人员不可多得的取暖之宝.该产品具有热敷镇痛的功效,深受风湿关节痛、肩周炎、腰腿痛、胃痛等患者的欢迎.该产品每个综合成本1到2元,市场售价8到10元,若日产100个,每个平均利润5元,效益可观,实乃致富好门路.  相似文献   

4.
我国太阳能资源十分丰富,目前最主要的利用方式是用于城乡居民热水供应,我国太阳能热水器已经安装了6000万平方米,预计2020年和2050年将分别达到2.7亿和5亿平方米,将替代高峰电力8000万千瓦和2亿千瓦,节约1200万千瓦和30000亿千瓦时的电能.我国太阳能热水器已经成为太阳能利用中应用最为广泛、产业化发展最迅速的领域,太阳能热水器的生产量和使用量都居世界第一.至2003年底,全国太阳能热水器使用量达到5200万平方米,占全球使用量的40%以上.目前我国太阳能热水器生产厂家超过3000家,年生产量超过1000万平方米,全真空玻璃管热水器在世界市场上占据主导地位.  相似文献   

5.
《技术与市场》2007,(9):24-24
海藻糖是一种稳定的非还原性双糖,广泛存在于低等植物、藻类、细菌、真菌、酵母、昆虫及无脊椎动物中,既是一种贮藏性糖类,又是应激代谢的重要产物.由于海藻糖是由特殊双糖分子构成的非还原性糖,特性非常稳定,能够在高温、高寒、干燥失水等恶劣的条件下在细胞表面形成特殊的保护膜,有效地保护生物分子结构不被破坏,从而维持生命体的生命过程和生物特征.海藻糖可广泛用于生物制剂、医药、食品、化妆品及农业科学等各个行业.  相似文献   

6.
收集了11省(市)23县(市)的23个鱼腥草种质资源,在浙江省丽水市林业科学研究所百果园基地进行种源特性观察试验,结果表明,23个种源从形态特征上可分为二大类,一类为生长初期叶绿色,茎节间较长,生长盛期叶翠绿色,叶缘波状,茎浅红色;另一类为生长初期叶带紫红色,茎节间较短,生长盛期叶墨绿色,叶近全缘,茎紫红色、浅红色或绿色。物候期较为一致,可分为破土萌芽长叶期(2月下旬到3月下旬)、快速高生长期(3月底到4月中旬)、开花结果期(4月下旬到6月底)3个阶段。不同鱼腥草种源在高、径生长和蒴果、种子数量等方面均存在显著差异。高生长以18号(浙江嵊州)种源最好,平均高度达83.08cm,15号(安徽绩溪)种源最低,仅为41.08cm;径生长以4号(云南会泽)种源最好(0.5063cm),15号(安徽绩溪)种源最差(0.3cm)。综合性状以4、18、19(浙江长兴)、12(浙江嘉善)、5(贵州安顺)、17(浙江泰顺)等种源表现较好,能获得较高的生物量。单果序蒴果数以7号种源(河南正阳)最多,达83.4颗/果序,蒴果内种子数以10号种源(广函柳州)最高(22.67粒/蒴果),综合蒴果和种子数量以10、5号种源较好。  相似文献   

7.
2008年4月1日,湖南省怀化市召开森林消防应急营成立大会,并举行了检阅仪式和实战演习.森林消防应急营共有340人,下设4个连和1个特勤队.人员分别由中坡国家森林公园护林员、国有泸阳林场一线产业工人和武警怀化支队官兵、怀化军分区预备役战士、武警怀化消防支队官兵组成.  相似文献   

8.
Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK.  相似文献   

9.
重阳木,为大戟科重阳木属落叶乔木,生长高大,枝叶茂密,树姿优美,城镇绿化多见孤植大树或小片成群栽植。重阳木深根性,抗风力极强,又是生长快的阳性树种之一,有些地方用以作防护林或用材林,效果很好。2005年,祁门县对赤岭口公路两旁重阳木进行病虫害调查,发现重阳木白带黑斑蛾幼  相似文献   

10.
1.加喂维生系C.俄罗斯的研究结果表明:当鸡舍温度为32℃时,在每千克饲料中添加60毫克维生素C,10周内可提高产蛋率12%左右;舍温为35℃时,在每千克饲料中添加44毫克维生素C,在20周内可提高产蛋率11%.在17.8至24.4℃的气温下,在每千克饲料中添加维生素C400毫克,3个月可增产约6%的鸡蛋;在7至20℃的气温下,在每千克饲料中添加30毫克维生素C,48周内增产鸡蛋7%.  相似文献   

11.
桤木人工林细根与土壤养分含量季节动态变化   总被引:2,自引:2,他引:0  
对桤木人工林细根、土壤养分含量的季节变化及其两者之间的关系进行了研究.结果表明:(1)桤木细根中大量元素N、Ca、K、Mg、P含量冬季高,春季最低;微量元素Fe、Mn、Zn、Cu、Pb、Ni、Cd含量冬季最低,春夏季较高.(2)土壤各层中大量元素N、Ca、K、Mg、P含量冬季最低,夏季最高;微量元素Mn、Zn含量在冬季最低,秋季最高;Fe、Ni、Pb、Cu、Cd含量在冬季最高,春秋较低.(3)细根和土壤中大量元素含量在冬季存在负相关关系,微量元素Fe、Ni、Cd含量在一年四季均存在显著负相关关系,Mn、Cu含量在春季、夏季和秋季存在负相关关系,Zn、Pb含量在春季、夏季和秋季存在正相关关系.  相似文献   

12.
遮阴处理对‘绿岭’核桃品质及产量的影响   总被引:1,自引:0,他引:1  
为了解‘绿岭’核桃对光照的需求及适应性,研究了不同遮阴程度(80%、50%、30%)对‘绿岭’核桃品质及产量的影响。结果表明:80%遮阴处理核桃种仁的脂肪含量极显著低于其它处理和CK,仅为57.38%,淀粉和可溶性糖含量极显著高于其它处理和CK,分别为3.08%和3.53%;80%遮阴处理的核桃单果质量极显著低于其它处理和CK,仅为8.34 g,其纵径、横径和侧径极显著低于其它处理和CK,分别为36.07、26.6、26.59 mm;80%遮阴处理的核桃密度和硬壳厚度极显著低于其它处理和CK,仅为0.46 g/cm3和0.66 mm;不同遮阴处理的坏果数量极显著高于CK,80%遮阴处理的坏果数量极显著高于其它处理和CK,达到216.83个/株;80%遮阴处理的内果皮发育不良率极显著高于其它处理和CK,达到68.17%;不同遮阴处理的核桃产量极显著低于CK,80%遮阴处理下的核桃产量极显著低于其它处理和CK,仅为1.04 kg/株。  相似文献   

13.
Carbon (C), nitrogen (N), and phosphorous (P) levels and their stoichiometry in plant components (leaves, branch trunks, roots) of trees in a karst forest and non-karst forest are compared. The results show that the C contents, C:N and C:P ratios of dominant species in the karst forest were lower than those in the non-karst forest, but the N and P and the N:P ratio were higher;C:N:P ratios in plant organs of trees in the karst forest were in the order of trunks>roots>branches>leaves. However, C:N:P ratio in the non-karst forest trees were trunks>branches>roots>leaves. Moreover, ratio of C:N:P in trunks was highest and lowest in leaves in both forests. In non-karst forest trees, N:P was in the order of leaves> roots>branches>trunks. There were no significant differences in the ratio of N:P in different plant components of trees in the karst forest. However, in karst and non-karst forest trees, the ratio of N:P in leaves was highest;positive correlations between N and P contents, and N and N:P ratios were observed in both karst and non-karst forests (p<0.001). Negative correlations between P and N:P ratios (p<0.05) were observed in karst forest trees, while positive correlations were observed in non-karst forest trees.  相似文献   

14.
We assessed the effects of ambient tropospheric ozone on annual tree-ring growth, delta(13)C in the rings, leaf gas exchange and visible injury in three ozone-sensitive woody plant species in southern Switzerland. Seedlings of Populus nigra L., Viburnum lantana L. and Fraxinus excelsior L. were exposed to charcoal-filtered air (CF) and non-filtered air (NF) in open-top chambers, and to ambient air (AA) in open plots during the 2001 and 2002 growing seasons. Ambient ozone exposures in the region were sufficient to cause visible foliar injury, early leaf senescence and premature leaf loss in all species. Ozone had significant negative effects on net photosynthesis and stomatal conductance in all species in 2002 and in V. lantana and F. excelsior in 2001. Water-use efficiency decreased and intercellular CO(2) concentrations increased in all species in response to ozone in 2002 only. The width and delta(13)C of the 2001 and 2002 growth rings were measured for all species at the end of the 2002 growing season. Compared with CF seedlings, mean ring width in the AA and NF P. nigra seedlings was reduced by 52 and 46%, respectively, in 2002, whereas in V. lantana and F. excelsior, ring width showed no significant reductions in either year. Although delta(13)C was usually more negative in CF seedlings than in AA and NF seedlings, with the exception of F. excelsior in 2001, ozone effects on delta(13)C were significant only for V. lantana and P. nigra in 2001. Among species, P. nigra exhibited the greatest response to ozone for the measured parameters as well as the most severe foliar injury and was the only species to show a significant reduction in ring width in response to ozone exposure, despite significant negative ozone effects on leaf gas exchange and the development of visible foliar injury in V. lantana and F. excelsior. Thus, significant ozone-induced effects at the leaf level did not correspond to reduced tree-ring growth or increased delta(13)C in all species, indicating that the timing of ozone exposure and severity of leaf-level responses may be important in determining the sensitivity of tree productivity to ozone exposure.  相似文献   

15.
白蜡虫在寄主植物上的分布特征研究   总被引:5,自引:3,他引:5       下载免费PDF全文
白蜡虫在寄主上的分布与方向和寄主枝条的位置有关,不同虫基分布特征不同,在定叶期,白蜡早咎群方位上差异不太大,但雌雄虫在方位分布上有明显差异。种群数量分布依次为东(28.05%),南(26.55%),西(25.06%),北(20.34%),雌虫依次为东(32.16%),南927.36%),北(20.34%),西(18.65%);雄虫依次为西(30.76%),南(25.84%),东(24.29%),北  相似文献   

16.
Studying contents and seasonal dynamics of active organic carbon in the soil is an important method for revealing the turnover and regulation mechanism of soil carbon pool. Through 3 years of field sampling and lab analysis, we studied the seasonal variations, content differences, and interrelationships of total organic carbon(TOC), light fraction organic carbon(LFOC), and particulate organic carbon(POC) of the soil in the forest areas burned with different fire intensities in the Daxing'anling Mountains. The mean TOC content in the low-intensity burned area was greater than that in the unburned area,moderate-intensity, and high-intensity burned areas in June and November(P0.05). LFOC and POC in the lowintensity burned area were greater than that in either moderate-intensity or high-intensity burned areas, with significant differences in LFOC in September and November(P 0.05). A significant difference in LFOC between the unburned and burned areas was only found in July(P 0.05). However, the differences in POC between the unburned and burned areas were not significant in all the whole seasons(P 0.05). Soil LFOC and POC varied significantly with the seasons(P 0.05) in the Daxing'anling Mountains. Significant linear relationships were observed between soil TOC, LFOC, and POC, which were positively correlated with soil nitrogen and negatively correlated with soil temperature in the Daxing'anling Mountains.  相似文献   

17.
森林经营综合效益评价方法与发展趋势   总被引:2,自引:1,他引:1  
加强森林经营和提高森林质量是我国林业现代化过程的重要内容和环节。不同经营模式对森林多功能影响及经济效益评价已经成为森林经营领域关注的热点之一。文中对森林经营综合效益评价的理论和方法进行评析, 综述近几十年来国内外森林经营的木材生产和碳储存效益评价, 重点介绍不同时期研究评价内容的变化; 在此基础上, 总结我国森林效益评价存在的不足, 指出今后研究的重点和发展趋势, 为推进我国森林经营朝着技术上可行、生态上友好、经济上可接受的可持续方向发展提供参考。  相似文献   

18.
19.
Autumnal changes in organic-S, sulfate-S, total-S and the ratios of organic-S to total-N and sulfate-S to organic-S were followed in leaves and adjacent bark of actinorhizal (Frankia-nodulated) black alder (Alnus glutinosa (L.) Gaertn.) and eastern cottonwood (Populus deltoides Bartr. ex Marsh.) trees growing on a minespoil site high in extractable soil sulfate, and in black alder and white basswood (Tilia heterophylla Venten.) trees growing on a prairie-derived soil in Illinois. Organic-S concentrations decreased significantly (P < 0.05) during autumn only in foliage of trees growing on the prairie-derived soil where losses of leaf organic-S were 65% for black alder and 100% for white basswood. Leaf sulfate concentrations were relatively stable throughout autumn in white basswood growing on prairie-derived soil and in black alder at both sites. Sulfate-S concentrations in leaves were significantly (P < 0.05) higher in trees at the minespoil site than in trees growing in the prairie-derived soil (5.1 mg g(-1) for the minespoil site and 1.2 mg g(-1) for the prairie-derived soil), and in the non-actinorhizal species during late summer. During the autumn, the ratio of organic-S to total-N doubled in leaves of eastern cottonwood at the minespoil site, but in black alder and white basswood growing on the prarie-derived soil, it decreased by 60 and 74%, respectively. Organic-S concentrations in bark increased more during autumn in species unable to fix atmospheric N(2), than in black alder. The results suggest that patterns of autumnal translocation of leaf S can be site-dependent and that leaf S and leaf N are, at least in part, translocated independently in the fall. Black alder and eastern cottonwood seemed to incorporate sulfate-S readily into organic substances in leaves when grown in soils with a high sulfate content.  相似文献   

20.
树叶中重金属含量及其指示大气污染的研究   总被引:4,自引:0,他引:4  
通过对南京市区交通流量大的区域和相时清洁区(江苏省林科院)不同植物叶片重金属元素(Pb、Cd、Cu)含量的分析,研究了大气污染指数,初步探讨了植物重金属含量与城市大气污染之间的关系.研究表明.植物叶片中重金属Pb、Cd和Cu的累积量与大气中Pb、Cd和Cu的相对含量呈显著正相关;所调查绿化树种叶片的重金属含量因重金属种类、采样区和树种的不同具有明显差异,悬铃木叶片累积Pb的能力最强,而杨树叶片对Cd和Cu的累积能力最强.市区大气重金属质量状况为:交通枢纽区中央门、南京化工厂和沪宁高速属于重污染,生活区新庄属于中轻度污染,远郊林科院属于无污染区.  相似文献   

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