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81.
通过对湖南省桑植县引种栽培的中华圣桃,进行环境适应能力和产量及品质的调查,总结出中华圣桃的引种栽培技术。中华圣桃在高海拔山地生长发育情况正常,产量稳定,经济价值高,完全适宜推广栽培。  相似文献   
82.
2012年以来,广西大化县大力推广玉米地膜覆盖、秸秆覆盖、集雨灌溉、适时套播等关键技术,使春、秋2季玉米在干旱少雨的条件下,仍能获得较高的产量。笔者通过近年来对该县玉米抗旱技术的应用调查,分析总结该县玉米抗旱生产的关键措施,以供山区玉米抗旱栽培参考。  相似文献   
83.
冬青属是冬青科植物在我国分布的唯一属,有较突出的观赏价值,但在乡土植物园林应用研究方面却 一直未得到足够的重视。鼎湖山境内冬青属植物种质资源丰富,多数至今尚未得到开发利用。通过对该区25 种“生 冬青属植物资源的实地调查,分析其种质资源、生境贮量、观赏特性,就加强鼎湖山冬青属植物的引种应用、生物学 研究和乡土园林景观应用研究,发挥园林绿化潜力,提升园林应用品质,服务生态园林城市建设及综合性利用提出 了指导性建议。  相似文献   
84.
  1. Global environmental change is threatening freshwater biodiversity with ecological impacts predicted to be particularly severe in high-altitude regions. Despite this, an ecological understanding of high-altitude pond networks remains patchy, with only limited knowledge of the environmental and spatial predictors of taxonomic and functional diversity. Moreover, previous studies of pond ecosystems have focused primarily on taxonomic richness and largely overlooked functional diversity.
  2. This study examined the influence of local environmental and spatial factors on taxonomic and functional α and β diversity (including the turnover and nestedness-resultant components) of 17 high-altitude (~2,500 m above sea level) pond macroinvertebrate communities, in the Macun Cirque, Switzerland.
  3. Spatial processes (pond connectivity) were important drivers for taxonomic α diversity, while local environmental variables (pond permanence and surface area) were important determinants of functional α diversity. Species turnover was the most important component of β diversity for taxonomic composition, and functional composition demonstrated a nested spatial pattern.
  4. Variation in taxonomic and functional composition (and the turnover and nestedness components of β diversity) were determined by local environmental variables despite the limited environmental gradients within the pond network. No significant effects of spatial variables on community composition were recorded for either facet of diversity, indicating that compositional variation was determined at a local scale. Water temperature, depth and pond permanence were consistently the most important measured drivers of diversity.
  5. Given the importance of both spatial and environmental variables in structuring taxonomic and functional diversity, landscape-scale conservation and management activities that aim to improve or protect high-altitude freshwater biodiversity should focus on maintaining connectivity among ponds and environmental heterogeneity, particularly pond surface area, water depth, and hydroperiod. Understanding the mechanisms driving taxonomic and functional diversity will be critically important for the management and conservation of macroinvertebrate communities in high-altitude pond networks in the face of climatic warming.
  相似文献   
85.
介绍了南方高海拔山地无毒马铃薯制种技术,主要包择、基地选择、精细整地、注意墒情和冻害、精选种薯、合理施肥、适时播种、化学除草、适时放苗、病虫害防治、收获贮藏等。  相似文献   
86.
随着旅游业的快速发展和城镇现代化的推近,景区周边涌现出了大量与景区不协调的问题,同时,由于人们对景区所处背景环境标准的提高,忽视周边环境与景区完整性的做法已不能适应新时代旅游者的需求。未来景区的竞争已延伸到景区周边环境范围。为此建议今后在景区规划工作中,亦应将制定科学详尽的周边环境保护整治规划放在重要位置,因此周边环境应有一个较为清晰的地域范围,以便于环境质量评价和规划运作,以及行之有效地落实周边环境调控。提出对景区周边环境地域范围定量界定的影响拐点法,并以绵山景区为例进行实证研究。结果显示景区能规划管理至定量方法所做的周边环境范围,无论对游客还是周边居民来说,满意度均较高。周边环境调控对于提高景区综合环境质量具有重要意义。  相似文献   
87.
用山路引理得到了一类带有Dirichlet边值条件的p-Laplacian方程的非平凡解的存在性及多解性.  相似文献   
88.
There are a series of city environmental problems especially in the mountain city along with the city fast development. In recent decade, many scholars have studied the urban heat island, the urban temperature, the urban wind field, the precipitation and the urban visibility etc. But the urban thermal environment has not been settled radically. All the measures have not been used in the practice. And the researches in thermal environment of the mountain cities are very few. So the authors consider Chongqing as the researching object. Chongqing is one of the typical mountain cities in the semi-tropical. Sequentially we find out the characteristic of the thermal environment in the mountain city. Further the authors seek for the measures to plan and build ecological city. They conclude that CFD can be used in the simulation of urban environment, and use the result of simulation in urban planning is possible. The thermal environment in the center of Chongqing needs to be improved.  相似文献   
89.
During the citified course at present for construction of old mountain cities is very important. This paper has analyzed the following problems: the contradiction for construction of cities, style of mountain cities, reconstruction of city construction and reflecting the features of our age from cities.  相似文献   
90.
Interspecific F1 hybrids were produced after artificial intercrossing of six Sideritis species indigenous to Greece, namely: S. athoa, S. euboea, S. syriaca, S. raeseri, S. scardica, S. clandestina and a cultivated clone of S. raeseri. It was found that all species cross with each other, but the level of crossability varied with the cross-combination. In the yield evaluation experiments, the interspecific hybrids with a common female parent were considered as a group. It was observed that yield during the year of establishment was relatively low, but the interspecific hybrids out-yielded the control in both fresh and dry weight. All hybrids produced higher yields in the following years and their productivity started to decline after the fifth year. All hybrids produced higher yields than the control in all six years of the experiment. The highest yield over the years, in fresh and dry weight, was produced by the group Sideritis raeseri cultivated clone (cc) ×Sideritis spp. This yield, however, was not always significantly different from the yield produced by the second in the rank group (S. clandestina×Sideritis spp.). A high correlation (r > 0.99) between fresh and dry weight was observed. The two groups with the highest yield also had the highest essential oil content. In addition, all the interspecific hybrids had a higher essential oil content than the control species. Furthermore, the essential oil content of the selected individual hybrid plants ranged between the midparental value to a value higher than the high-parental species, indicating an additive and dominance gene action. It was also found that the content of the essential oil in the seven most important components (pinene, lemonene, cynene, menthone, copaene, caryophyllene and valerianic ester) varied from hybrid to hybrid. Given that Sideritis reproduces mainly asexually, the direct use of individual interspecific hybrids with higher yield and content in essential oil than the control species is possible in cultivation.  相似文献   
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