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1.
We studied the vegetational and avifaunistic changes following rural depopulation in an area covering 2,600 ha north of Montpellier (Southern France). The study area is covered by a mosaic of Mediterranean habitats that includes cultivation, grasslands, shrublands, and woodlands and is representative of the natural features present and of the human usage practiced so far in this part of the Mediterranean. We sampled the vegetation and the bird fauna in the same 193 census plots in 1978 and in 1992. At both the habitat and landscape scales the cover of woody plants increased significantly. Open habitats tend to disappear. As a consequence the abundance of open-habitat bird species decreased significantly whereas the abundance of forest birds increased significantly. These changes favor a pool of forest species widespread in western Europe and reduce habitat availability for open habitat and shrubland species. Many of the latter are Mediterranean species whose distribution in Western Europe could become reduced under current landscape dynamics. Our observation of more woodlands and their typical birds and of less open habitats and their associated avifauna is not consistent with the traditional worry shown by the public and the managers about the regression of forests and woodlands in the Northern Mediterranean as a consequence of fire.  相似文献   
2.
不同副梢处理对赤霞珠葡萄生长和结果的影响   总被引:7,自引:1,他引:7  
试验以3~5年生赤霞珠葡萄(CabernetSauvignon)为试材,对其进行了不同的副梢处理:只留顶端1个副梢、副梢绝后处理、花序以上反复摘心、副梢全留。2年的结果表明:副梢全留(所有副梢全留2~3片叶反复摘心)处理的叶面积指数高,果实的产量和品质高。因此,相对多留副梢叶片,改善了叶幕叶龄结构,提高了果实品质,有利于枝梢成熟。  相似文献   
3.
This study was performed to determine pharmacokinetic profiles of the two active metabolites of the analgesic drug metamizole (dipyrone , MET), 4‐methylaminoantipyrine (MAA), and 4‐aminoantipyrine (AA), after intravenous (i.v., intramuscular (i.m.), and oral (p.o.) administration in cats. Six healthy mixed‐breed cats were administered MET (25 mg/kg) by i.v., i.m., or p.o. routes in a crossover design. Adverse clinical signs, namely salivation and vomiting, were detected in all groups (i.v. 67%, i.m. 34%, and p.o. 15%). The mean maximal plasma concentration of MAA for i.v., i.m., and p.o. administrations was 148.63 ± 106.64, 18.74 ± 4.97, and 20.59 ± 15.29 μg/ml, respectively, with about 7 hr of half‐life in all routes. Among the administration routes, the area under the plasma concentration curve (AUC) value was the lowest after i.m. administration and the AUCEV/i.v. ratio was higher in p.o. than the i.m. administration without statistical significance. The plasma concentration of AA was detectable up to 24 hr, and the mean plasma concentrations were smaller than MAA. The present results suggest that MET is converted into the active metabolites in cats as in humans. Further pharmacodynamics and safety studies should be performed before any clinical use.  相似文献   
4.
方武 《湖南农机》2011,38(7):190-191
随着新一轮的中职学校德育课课程改革的深入开展和中职学生主体意识的增强,传统的德育课教学有许多方面需要进一步改进和完善.在中职学校德育课教学中实施高效良性的师生互动,能提高德育课的教学实效和学生的思想道德素质,为学生职业生涯发展奠定基础.  相似文献   
5.
污水处理已成为城市建设中必不可少的环节,所以对相应的配套工程也提出了更高的要求,本文将对污水处理厂的供配电系统进行简要的分析。  相似文献   
6.
甲基营养型芽胞杆菌的研究进展   总被引:2,自引:0,他引:2  
甲基营养型芽胞杆菌是一种无致病性的细菌,对外界环境具有多抗逆性,作为芽胞杆菌属的"后起之秀",被越来越多的应用于各行业中。本文主要从甲基营养型芽胞杆菌的生理生化特征、代谢产物及应用等方面论述其研究进展。  相似文献   
7.
8.
Drought is a common abiotic stress that considerably limits crop production. The objective of this study is to explore the influence of water deficiency on the yield, physiologic and metabolomic attributes in upland cotton cultivars(Gossypium hirsutum L). Cotton cultivars, 'Ishonch' and 'Tashkent-6' were selected to study the relationships among their physiologic, metabolomic and yield attributes during water deficiency. Deficit irrigation was designed by modifying the traditional watering protocol to reduce water use. Results indicate that cotton cultivars respond differently to water deficit stress. Water deficit significantly influenced plant height, the number of internodes, and sympodial branches in both cultivars. However, yield components such as the number of bolls, boll seed, lint mass, and individual plant yield were significantly reduced only in 'Tashkent-6'. The leaf area decreased and the specific leaf weight increased in 'Ishonch' under deficit irrigation conditions. However, 'Tashkent-6' demonstrated significant water loss compared to 'Ishonch', and both cultivars showed reduced transpiration rates. Untargeted metabolite profiles of leaves showed clear separation in 'Ishonch', but not in 'Tashkent-6' under deficit irrigation compared to full irrigation. The individual metabolites such as proline and galactinol showed strong association with yield under water deficit stress. Moreover, this study indicates that leaf area and transpiration intensity influence yield during water deficiency. In summary, the correlation among morpho-physiologic, metabolic, and yield components significantly varied between the two cultivars under water deficiency. The flowering stage was sensitive to water stress for both cultivars. The direct relationship between physiology, metabolism, and yield may be a useful selection criterion for determining candidate parents for cotton drought tolerance breeding.  相似文献   
9.
During the long process of evolution, plants have adapted to their environments through the biosynthesis of secondary metabolites (SM) using the acetate-malonate pathway, mevalonic acids pathway, or shikimic acid pathway, leading to resistance to different pests. As a major cash crop, cotton can produce many secondary metabolites with insecticidal activity, and show self-defense mechanisms under biotic stress conditions. These characteristics of cotton ensure reduced pest incidence and maintenance of ecological balance. This paper discusses the types of SMs, their synthesis, and insect resistance of cotton secondary metabolites in relation to their defense function. We propose possible pest-control strategies using secondary metabolites in cotton.  相似文献   
10.
张会 《湖南农机》2015,(3):112+114
当前,农业类中等职业学校正处于发展的上升期,日新月异,成绩喜人。通过打造学校特色名片提升学校知名度,同时也要强化软硬环境建设,并着眼于以人为本的大局才能使中等职业学校更快更好地发展。  相似文献   
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