我国地被植物研究开发现状及其对策

近年来,随着生态城市的发展,作为园林配置不可缺少的素材--地被植物越来越受到人们的重视.本文对地被植物的调查、筛选利用、引种、育种和抗性等方面的研究现状进行了总结,并针对目前地被植物在应用中存在的一些问题,指出地被植物研究、开发、利用的途径与对策.     

我国园林地被植物研究现状

园林地被植物与草坪是一门新兴的应用科学。近几十年来,在全球范围内,环境污染日趋严重,已直接威胁到人类的生态安全,人们开始认识到地面绿色植被的重要性,把发展草坪与地被植物作为改善环境、保护环境、消除裸地的有力措施之一。各大城市为了摸清当地的地被植物资源,研究和筛选适宜当地栽培和应用的地被植物优良种和品种,开展了多方面的研究工作。鉴于此,综述了近年来国内园林地被植物的研究,侧重于新优地被植物的引种、园林地被植物资源调查和利用以及地被植物的适应性和耐性研究等几个方面,并提出野生地被植物具有广阔的应用前景,应该进行更多相关方面的研究。     

北京地区野生草本地被植物引种、筛选与利用

从北京地区地被植物应用现状分析,得出引种野生草本地被植物是丰富城市景观、增加物种多样性经济有效的途径。通过对北京及周边6省2市的植物调查、引种建立了野生草本地被植物引种园,引入野生草本地被植物共44种。经过一年的物候观测,初步选出适合北京园林绿化利用的草本地被植物20种。     

深圳市公园绿地地被植物应用现状调查与分析

以深圳市有代表性的21个城市公园地被植物为研究对象,通过实地调研地被植物的种类、应用形式及生长状况等,统计分析每种地被植物的应用频度,重点针对林下、林缘地被以及近年来出现的新优地被植物的应用形式及效果进行了研究。共记录应用地被植物108种,爵床科、龙舌兰科、百合科、茜草科、天南星科等亚热带分布科占应用地被植物种类的60%以上;观花、彩叶地被在林缘和草坪绿地内花境中应用广泛;通过调查分析提出,应加强乡土观花地被植物和蕨类植物的开发利用,提高林下耐阴和观花地被植物的应用比例,提升精细化养护管理水平。本研究为华南地区园林地被植物的选择和应用提供了指导。     

北京地区野生草本地被植物引种、筛选与利用

从北京地区地被植物应用现状分析,得出引种野生草本地被植物是丰富城市景观、增加物种多样性经济有效的途径.通过对北京及周边6省2市的植物调查、引种建立了野生草本地被植物引种园,引入野生草本地被植物共44种.经过一年的物候观测,初步选出适合北京园林绿化利用的草本地被植物20种.     

园林地被植物在景观设计中的应用

阐述了园林地被植物应用现状,科学分析其功能,并在此基础上提出地被植物景观设计原则,进一步完善了地被植物的研究与应用。     

长春市乡土园林地被植物物种组成与多样性分析

长春市绿地具有丰富的乡土地被植物资源,为揭示城市乡土地被植物物种组成与多样性特征,本研究以长春市595块样地为对象,调查了乡土地被植物种类、群落郁闭度、高度、密度和盖度,测定了有代表性样地土壤理化性质。研究结果表明,长春市各类绿地共有乡土园林地被植物40科83属95种,百合科(Liliaceae)重要值为31.93%,...     

地被植物在北京园林绿化中的研究应用概述

系统综述了地被植物的概念、分类及其在北京地区研究应用的历史与现状,分析了园林地被植物在科研与应用中存在的主要问题,在此基础上,简要阐述了地被植物的科研发展方向,并对其应用前景作了展望。     

浅谈地被植物在园林绿化中的应用

随着人们生活水平的提高,居民对所处的生态环境有了更高的要求。衡量一个城市生态效益的主要标尺主要是指该城市园林建设的模式以及地被植物在园林中的应用方式。研究地被植物在园林中的应用可以通过对生态园林中地被植物的种类和这些地被植物所带来的生态效益两方面出发。本文主要从提高城市生态环境和城市美观程度入手,对城市园林当中地被植物的应用做出探讨,希望能够对其他城市的园林建设以及地被植物的选择和应用提供可靠的理论依据。     

湖南云山野生地被植物资源及其综合评价分析

为深入了解和更好地开发利用湖南云山野生地被植物资源,采用野外调查和查证相结合的方法,运用层次分析法(AHP),对湖南云山野生地被植物资源及其综合评价进行了全面系统的研究与分析。结果表明,云山共有野生地被植物498种,隶属107科254属,其中蕨类植物14科20属30种,双子叶植物80科194属406种,单子叶植物13科40属62种,裸子植物缺乏。生活型以草本类为主,有201种,占总种数的40.36%,而藤本、灌木、蕨类和竹类所占比例较少,分别占总种数的29.52%,23.49%,6.02%和0.60%;其中直立型、缠绕攀援型和蔓生匍匐型地被植物所占比例相差较大,分别占总数的59.84%,29.52%和10.64%,大部分地被植物观赏性高、适应性广、抗逆性强;该区有Ⅰ级地被植物30种,具备良好的地被植物特性,综合评价值最高,是优良的乡土地被植物,可大规模开发利用;Ⅱ级地被植物82种,具备较好的地被植物特性,综合评价值较高,可适度开发利用;Ⅲ级地被植物103种,因个别指标分值相对偏低,可选择性开发利用;Ⅳ级地被植物283种,由于某些指标分值相对较低,只能适当选择,小面积应用。总之,湖南云山野生地被植物资源丰富且大部分具有良好的地被植物特性,在开发利用时应结合工程实际,合理地选择,灵活地运用,以最大限度地发挥其综合效益。     

3种野生耐荫地被植物的调查与评价

在对野生草坪地被植物调查的基础上,重点筛选出蛇莓Duchesnea indica,活血丹Glechoma longituba和过路黄Lysimachia christinae 3种野生耐荫草坪地被植物.调查表明,它们都是匍匐生根型多年生植物,叶形奇特、形态优美、青绿期长、易繁殖、成坪速度快、易管理,能形成低矮、均匀、平整而美观的草坪地被.     

香港草地群落类型及生物量的研究

香港地区的草地是次生性植被 ,它覆盖了香港地区绝大部分的山地。草地群落可分为南亚热带禾草草地、南亚热带蕨类草地 2个群系组共 17个群系。禾草草地和蕨类草地地上生物量分别是589g/m2 和 4 75g/m2 ,地下生物量分别是 784 g/m2 和 12 77g/m2 。地上现存生物量与温度、雨量和光照三者密切相关 ,成明显的线性关系     

不同下垫面每次降雨水土流失特征及影响因素分析

研究了不同下垫面每次降雨产流产沙特征及其与降雨、降雨前期条件的内在关系。结果表明,百喜草覆盖和敷盖处理的产流产沙均远小于对照处理,相对对照处理,减水率在95%以上,减沙率在99.9%以上。影响百喜草覆盖和敷盖处理产流、产沙的最主要因素为降雨量,其次为降雨历时。同时,在影响百喜草覆盖和敷盖处理产沙因素中,产流影响显得更密切,也更直接。而对于对照处理,影响产流、产沙的最主要因素为降雨量和降雨强度,而且降雨量主要影响产流,降雨强度则主要影响产沙。     

2000-2019年青海地区植被总初级生产力遥感估算及时空变化分析

青海作为三江源所在地,监测其生态系统变化对我国的生态文明建设具有战略意义.植被总初级生产力(GPP)是陆地生态系统碳循环的重要组分.采用MODIS卫星遥感数据和土壤背景校正NIRv模型,结合3个地面站点的通量观测数据,估算了2000-2019年青海地区的GPP,并结合土地利用数据和气象数据分析了其时空分异特征及对气候变...     

Survival of Ancylostoma caninum on bare ground, pea gravel, and concrete.

Studies were done to determine the survival of infective Ancylostoma caninum 3rd-stage larvae on 3 ground covers commonly used in dog run construction: bare ground, pea gravel, and concrete. Changes in numbers of recovered larvae were compared to meterologic data and the most significant weather variables were determined. Larvae were recovered 1 to 7 days on bare ground. Larvae survived longer in the fecal mass (mean of 3 days) than on the bare ground (mean of 2 days). Rain was the most significant variable, in that it was positive in its effects (higher larval count) early in the experiment (causing fecal mass breakdown and release of larvae) and negative (lower larval count) later in the experiment (spreading larvae away from test site). Larvae were also recovered 1 to 7 days on pea gravel. They were recovered for a mean 2.6 days from the fecal sample, a mean of 1.5 days from the rocks directly below the fecal mass, and a mean of 1.3 days from the remaining rocks. Here also, rain was the most significant weather factor. It was negatively significant (lower larval count) for the fecal mass (spreading of the larvae) and positive for those in the pebbles (increasing the moisture in the pebbles). Survival time of larvae on concrete was shorter than that on the other 2 substrates: from 0 to 2 days. Larvae were recovered a mean of 1.3 days from the fecal mass and a mean of 0., days from the surrounding concrete. Rain was positively significant early in the experiments in that it released trapped larvae from the fecal mass. Sunlight consistently was negatively significant (lower larval count) due to its lethality to the unprotected larvae.     

盐胁迫下星星草幼苗的生理反应──Ⅰ．盐胁迫对星星草幼苗生长的影响

用模拟松嫩草地碱化土壤离子组成配制的混合盐溶液处理星星草幼苗，测定了长度和鲜重的变化。盐胁迫对星星草（Ｐｕｃｃｉｎｅｌｌｉａｔｅｎｕｉｆｌｏｒａ）幼苗长度增长的抑制作用是地上部略强于地下部，而对于鲜重增长的抑制作用是地下部略强于地上部。     

From research measurements to application: Bridging the gap; Overview of practical and scientific measurements in nutrition

Research that advances the practice of poultry nutrition covers a wide range, including fundamental studies that explore mechanisms in cells or a small number of birds and applied research that determines product yield in authentic production facilities. Ultimately, the applied research informs the economic analysis necessary for implementation of novel nutritional strategies or products. Nutritional controversies arise from applied research experiments that were not designed and interpreted based on the realities learned from mechanistic work. The experimental design and measurements selected for comparing nutrient sources or setting nutrient recommendations should be informed by underlying mechanistic information, such as the relative priorities of cells and tissues for the nutrient and the shape of the dose response relationship across a wide range of added dietary levels of the nutrient. Integrating mechanistic and applied research provides more robust results that can be used across wider ranges of diets and husbandry conditions.     

Avian cytology.

An overview of avian cytology is presented, discussing more common abnormalities that are encountered in routine clinical practice. The general cytologic features of inflammatory, infectious, and neo-plastic lesions are described. The remainder of the article covers major cytologic abnormalities by anatomic site of origin of the specimens.     

Heterogeneity of Pericyte Populations in Equine Skeletal Muscle and Dermal Microvessels: A Quantitative Study

The objective of this ultrastructural investigation was to determine if populations of pericytes in equine dermal and skeletal muscle capillaries increase in a head-to-foot direction, as has been reported in human skeletal muscles. Samples of equine microvessels were obtained from the longis-simus dorsi skeletal muscle 150 cm. from the ground, from the dermis above this muscle, from the extensor carpi radiali muscle at 55 cm. from the ground, from the dermis adjacent to that muscle, and from dermis 15 cm. from the ground, just above the hoof wall. Tissues were processed for transmission electron miscroscopy. Electron micrographs were analyzed with a digitizing tablet and computer, to determine the ratios of endothelial cell outer circumference and pericyte inner lengths. Pericytes were separated into two classes; those closest to the endothelial cells were defined as covering capillaries. Those separated from endothelial cells by another layer of pericytes were termed enveloping pericytes. There was much greater coverage and envelopment of dermal capillaries (85 % and 135 %) than skeletal muscle capillaries (27 % and 31 %). Regression analysis of the pericyte coverage and envelopment of dermal capillaries revealed a significant increase in pericytes toward the ground. Similarly, the two skeletal muscle tissues differed significantly in their pericyte coverage and envelopment (25/27 % at 150 cm., 31/35 % at 55 cm.). The data indicate that, as in humans, capillary pericytes are not homogeneously distributed within the same tissues, but are more numerous closer to the ground. Differences in pericyte populations could affect studies of microvessel function.     

Objectivity of BSE symptoms using Bayes theorem

In clinical epidemiology the Bayes theorem finds ever more use to render clinical acting more objective. It is shown that unusual examinations of BSE (bovine spongiform encephalopathy) as noise producing with ladle covers may quite objectively be evaluated. With the help of the likelihood ratio computed thereby, also a ranking of importance (clinical utility) of symptoms can be provided. The single most important symptom for BSE is photosensibility.