首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 937 毫秒
1.
云南干热地区与小粒咖啡原产地气候相似 ,因气候干热 ,干湿季分明 ,昼夜温差大 ,种植的小粒咖啡不仅投产早、病虫轻、产量高 ,而且具有味道醇和、香气浓郁的独特风味 ,在国内外市场上占有重要地位。但干热区种植小粒咖啡也因降雨不足、干燥度大 ,常出现落花多、枯枝多、干果多等问题。根据小粒咖啡生长发育习性及干热区气候特点 ,主要栽培技术措施是 :1 选用优良品种 ,培育健壮苗木1.1 选用适宜品种选用优良品种应同时具有高产、优质、抗旱、抗寒等特性。除原来主要种植的品种波邦、铁毕卡等品种外 ,现引进推广的卡蒂莫系列、SL系列等在…  相似文献   

2.
元谋干热河谷是我国典型的生态脆弱区,该区气候炎热干旱,植被退化严重,水土流失强烈,给造林工作增加了很大的困难。木豆根部具有根瘤,是干热河谷地区荒山、退耕还林地造林的优良树种。在对印度木豆多年适应性研究和木豆造林的实践经验基础上,总结了在该区域采用木豆进行造林的关键技术,即选择合适品种,采用鱼鳞坑或隔坡水平沟整地造林方式,施足底肥,直播造林,加强管理等。可为干热河谷区的造林提供参考。  相似文献   

3.
依据云南的气候条件,将云南省初步区划为6个板栗栽培区,即温热种植区,干热种植区,湿热种植区,滇东南湿热岩溶山原种植区,滇东北、滇西北温暖种植区,滇东北低温高湿种植区;并依据24个板栗新品系的区域化栽培试验结果,提出了各栽培区的适宜品种.  相似文献   

4.
云南省板栗栽培区划   总被引:1,自引:0,他引:1  
依据云南的气候条件,将云南省初步区划为6个板栗栽培区,即温热种植区,干热种植区,湿热种植区,滇东南湿热岩溶山原种植区,滇东北、滇西北温暖种植区,滇东北低温高湿种植区;并依据24个板栗新品系的区域化栽培试验结果,提出了各栽培区的适宜品种。  相似文献   

5.
干热河谷区环境脆弱,生态修复困难。在我国,干热河谷主要分布在金沙江、红河、澜沧江和怒江等流域。结合国内外相关研究,梳理我国干热河谷区的气候特征、土壤特征、植被情况及造林技术,分析干热河谷区生态修复的优缺点,提出对策和建议。结果表明,我国干热河谷区生态修复树种配置较单一,造林成活率较低,综合效益较差;需优化造林树种及配置,创新造林方法及种植设备,保护原生生态环境,建立长期生态环境监测及效益评价体系。  相似文献   

6.
干热河谷区即热量条件丰富的干早、半干旱河谷性气候区的统称。一般把我省年降水量<1000毫米,蒸发量>降水量,相对湿度≤70%,干燥度>1.5,具南亚热带气候指标的某些地区区划为干热河谷区。干热河谷区海拔的上限多在1300m或1500m。植  相似文献   

7.
《林业工作参考》2007,(2):91-97
根据《中华人民共和国种子法》第十六条和《云南省林木种子条例》第十三条的规定,经云南省林木品种审定委员会审定,卡蒂姆CIFC7963(F6)等2个林木品种通过审定,盈江县云南石梓母树林种子等10个林木品种通过认定(名录见附件),现予以公告。自公告发布之日起,这些品种可以在公告规定的适宜种植范围内作为林木良种推广使用。  相似文献   

8.
通过对金沙江干热河谷实地考察与资料分析,初步划定了各地干热河谷的上限和层域范围。提出了地形是影响金沙江干热河谷水分变化的主要因子,确定以坡向和坡位作为金沙江干热河谷立地类型划分的主要依据,划分的立地类型分别是:坡上灌丛区,分坡上灌丛区阴坡类型、坡上灌丛区阳坡类型;坡下草丛区,分坡下草丛区阴坡类型、坡下草丛区阳坡类型;坡足冲积区;河谷平坝区。据此,针对干热河谷各立地类型的特点提出了相应的造林技术措施。  相似文献   

9.
程海流域地处金沙江干热河谷区,天然植被稀少,生态环境脆弱,开展植被恢复工作难度较大。为了提高程海流域干热河谷区森林覆盖率,以及生物多样性和景观多样性水平,在全面调查的基础上,文章分析了该区域自然环境特点,并从营造防护林、特殊用途林、用材林、薪炭林、经济林的角度系统论述了植物种类选择情况,最后总结了干热河谷区植被恢复及植物种类选择的要点,以期为金沙江流域干热河谷区的生态修复研究与实践提供参考。  相似文献   

10.
文章通过对四川攀西干旱干热河谷区自然地理条件调查研究,按照水、热、土等因子将该区划分为四大类型区即:高海拔干冷区、中海拔干凉区、中低海拔干暖区、低海拔干热区;建立了干旱干热河谷退耕还林地的土地质量评价体系,并根据立地条件和经营条件对该区的退耕还林模式进行了探讨。  相似文献   

11.
本文记述了中国松叶蜂昆虫两新种,马尾松吉松叶蜂和油松吉松叶蜂。文中附有形态特征图4幅。  相似文献   

12.
Chemical study and medical application of saponins as anti-cancer agents   总被引:1,自引:0,他引:1  
Saponins are a group of naturally occurring plant glycosides, characterized by their strong foam-forming properties in aqueous solution. The presence of saponins has been reported in more than 100 families of plants out of which at least 150 kinds of natural saponins have been found to possess significant anti-cancer properties. There are more than 11 distinguished classes of saponins including dammaranes, tirucallanes, lupanes, hopanes, oleananes, taraxasteranes, ursanes, cycloartanes, lanostanes, cucurbitanes and steroids. Due to the great variability of their structures, saponins always display anti-tumorigenic effects through varieties of antitumor pathways. In addition, there are a large amount of saponins that still either remain to be trapped or studied in details by the medicinal chemists. This article reviews many such structures and their related chemistry along with the recent advances in understanding mechanism of action and structure–function relationships of saponins at the molecular and cellular levels. These aglycones have been described and their classification and distribution have been listed in the review. Some special saponins with strong antitumor effects have also been exhibited. Ginsenosides, belonging to dammaranes, have been found beneficial targeted on inhibition of tumor angiogenesis by suppressing its inducer in the endothelial cells of blood vessels, and then on prevention of adhering, invasion, and metastasis of tumor cells. Dioscin, one of the steroidal saponins, and its aglycone diosgenin also have been extensively studied on its antitumor effect by cell cycle arrest and apoptosis. Other important molecules discussed include oleanane saponins such as avicins, platycodons, saikosaponins, and soysaponins along with tubeimosides.  相似文献   

13.
Decomposition of Scots pine needle litter originating from five stands treated with different amounts of nitrogen fertilizer was measured over a 4‐year period in a mature Scots pine forest. The litter types, which differed in initial concentrations of nitrogen, phosphorus, potassium, and sulfur, but not in gross organic composition, were studied with respect to mass loss, ingrowth of total fungal mycelium, and net release of nutrients. During the first year of decomposition, rates of mass loss and ingrowth of fungal mycelium were highest in the nutrient‐rich litter. Phosphorus concentration was found to be the main factor affecting mass‐loss rate, and the rate of fungal ingrowth was positively correlated with initial nitrogen concentration. After this initial period, decomposition rates decreased, and after 4 years, accumulated mass loss and amounts of fungal mycelium were similar in all five litter types. These findings may be due, in part, to a lower rate of lignin decomposition in nitrogen‐enriched litter. Of the elements, potassium and magnesium were most rapidly lost from the litter, and their release was most pronounced during the first year. Calcium release was proportional to the loss in organic matter. Initially, the release of nitrogen and phosphorus was positively related to their concentrations in litter, however, during later stages of decomposition the differences among litter types levelled out. There was a tendency for concentrations of all elements, except nitrogen, in the different litters to approach similar levels as decomposition proceeded. Thus, after 4 years the nutrient composition of the various litter types was very similar, except for higher nitrogen concentrations in the originally most nutrient‐rich litters. The importance of the results in terms of substrate quality in fertilized as well as in non‐fertilized forests is discussed.  相似文献   

14.
一个世纪来黑龙江省森林景观动态研究   总被引:1,自引:0,他引:1  
With the help of GIS tool of ARC/INFO,ARCVIEW and FRAGSTATS,the map of forest resource distribution of Heilongjiang Province was analyzed in 1896,1949 and 1981.Using total area,mean patch size,patch density,coefficient of patch size variation,mean patch fractal dimension and mean shape index,we studied the change of forest landscape pattem and the change of each patch types in this region.As a result,the total area of forest landscape and mean patch size decreased sharply,the quantity and density of patches increased,the juxtaposition of patches weakened,the shape of patch tended to become regular,and the border of patch simplified.All these showed that the forest landscape of this area tended to fragment gradually,and the fragment of Korean pine forest is the severest.the diversity of whole forest landscape and the eveness of landscape types distribution reduced gradually.Human impact,instead of climate change and forest community succession,is the most important reason for such dramatic chages.  相似文献   

15.
对桂北全州县咸水镇种植的尾赤桉、尾巨桉等6个速生桉无性系的生长表现、寒害状况进行了调查分析,结果表明:不同速生桉无性系间生长差异显著,以无性系3(尾巨桉)、5(尾巨桉)、6(尾赤桉)3个无性系号生长最好,1号(柳窿桉)无性系生长最差。冻害是检验速生桉无性系能否适应的关键指标,所种植的速生桉无性系受冻严重,在冰雪袭击下所有试验树木均被全部压断,部分树木还被冻死而不能萌芽。类似全州县成水镇的气候条件不适宜种植尾巨桉、尾叶桉、柳窿桉等速生桉无性系。  相似文献   

16.
采用典型样株和随机取样的方法,对五味子种耔性状进行系统研究.结果表明:无性系间的种籽横径、种籽纵径、种籽厚度、种籽千粒重、种仁千粒重、种仁含油率等性状的差异达极显著水平;在供试的20个无性系中,9911、9907、9913、9919、9918、9914等6个无性系种仁含油率较高,分别为70.17%、69.77%、68.99%、67.51%、65.97%、64.15%;五味子种油的形成、积累与无性系的种籽千粒重、种仁千粒重、种籽横径、种籽纵径等指标关系不密切,而与种耔厚度关系密切,相关系数为0.670,相关关系达极显著水平.本研究结果可为以高含油率为目标的五味子品种选择提供依据.  相似文献   

17.
为了明确福建省樟树溃疡病的病原菌种类,对福建省福州市仓山区、三明市明溪县、南平市建阳区和顺昌县4个地区采集的樟树枝干溃疡样本进行分离、纯化和致病性分析,将病原菌进行系统形态学观察,并结合代表菌株的核糖体基因内转录间隔区(ITS)、翻译延伸因子(EF-1α)、RNA聚合酶Ⅱ大亚基(RPB2)和β-微管蛋白(BT)基因序列进行同源性分析,构建进化树,最终确定病原菌种类。结果表明,在福建省不同地区内采集到的75份樟树溃疡样本,经过组织分离、纯化和致病性检测,得到43个病原菌株,根据观察病原菌的菌丝生长状态和孢子特征,并结合系统进化树的结果,得到小新壳梭孢(Neofusicoccum parvum)、可可毛色二孢(Lasiodiplodia theobromae)、假可可毛色二孢(Lasiodiplodia pseudotheobromae)和Lasiodiplodia iranensis 4种类型菌株。接种菌株后发病症状与野外发病症状相同,但致病程度不同,其中小新壳梭孢最强,可可毛色二孢次之,L.iranensis最弱。  相似文献   

18.
Five Aigeiros section poplar clones were adopted as parents to produce five full-sib families through cross-breeding. Morphological, ecophysiological, and growth characteristics of the five parents and their 15 superior F1 generations were investigated during 45 days of flooding followed by a 10-day recovery period. Cuttings were subjected to two treatments: watered (control) and flooded to 10 cm above the soil surface. Results showed that flooded cuttings showed significant reduction in growth of height, root-collar diameter and leaf area, and root and total biomass yield. All 20 clones formed hypertrophied lenticels and adventitious roots by day 6–14 of flooding. In flooded cuttings, net photosynthesis, stomatal conductance, transpiration, and chlorophyll fluorescence were decreased significantly compared with the control. After flooding ended, all plants recovered rapidly. Generally, progenies showed higher growth of height, root-collar diameter, root biomass and leaf area than their parents both under flooding and control conditions, showing that heterosis existed in F1 generations, regardless of flooding. However heterosis was lower under flooding conditions than in the control. Under flooding, the highest heterosis of higher-parent in height and root-collar diameter were 68.63 and 20.83%, respectively. Variability of flood tolerance among progenies was clear in growth of height and root-collar diameter. Selection criteria for parents in cross-breeding were different between control and flooding. Relative effect values of the specific combining ability (SCA) and relative effect values of the general combining ability (GCA) of parents were more important than their flood tolerance. Progenies with a higher level of flood tolerance could be obtained, even from parents intolerant to flooding. In terms of breeding, height growth would be most important characteristic to measure in flooding conditions, and root-collar diameter growth was also very useful. Based on all measured values, the tested 20 clones were classified into three groups using hierarchical cluster analysis. Clones Lu, E4, E9, E29, A2, A8, A9, B1, B3, B4, and D8, were flood-tolerant. Clones Lf, Ha, Lm, D1, D7, F9, and F21 were moderately flood-tolerant. Clones Sm and F13 were flood-susceptible.  相似文献   

19.
本文利用现有资料以及实地调查,对川西地区(甘孜、凉山)的鱼类多样性进行了分析研究。结果表明:①川西地区共有鱼类9目19科82属148种和亚种,分别占整个四川(含重庆)鱼类的61.16%和整个中国鱼类的6.15%;②各科鱼类的种数分布为鲤科最多,为82种,占整个川西鱼类总数的55.41%,其次为鳅科,占14.19%。③川西地区是鲤科鱼类的东亚类群向西扩布的西缘地带,是青藏高原鱼类区系向东延伸的东缘地区,同时是南亚鱼类向北分布的北缘区域;④川西鱼类的垂直分布状况因地貌、海拔高度变化以及生态环境的差异等呈现出一定的规律性。此外,本文还对川西鱼类资源的保护提出了建议和对策。  相似文献   

20.
中国姜花属Hedychium野生花卉资源特点   总被引:3,自引:0,他引:3  
胡秀  刘念 《广东园林》2009,31(4):7-11
我国野生姜花属植物有32种、2变种和2变型,共计36个分类群,主要分布于西南部。以形态特征为主结合各个种的分布、生境等特点可将现有的种类分为毛姜花类群、白姜花类群、滇姜花类群、密花姜花类群、红姜花类群、盈江姜花类群等6大类群,以方便识别和开发利用。我国该属植物在植株高矮、花期、花色、花香、花序是否高出叶面、耐热性等方面均具丰富变异。为园林应用提供了丰富的种质资源。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号