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11.
不同生境小花山桃草自然种群表型变异与协变   总被引:1,自引:0,他引:1  
小花山桃草自然种群的表型特征是其对自然生境适应的结果,不同生境种群间表型特征的比较可为揭示其表型变异产生的原因及变异规律提供重要线索。本研究以分布于不同生境的5个小花山桃草自然种群为研究对象,研究了16个表型性状的变化特点。研究结果表明,小花山桃草表型多样性较为丰富,表型性状的平均变异系数为36.30%。表型分化系数在26.85%~96.98%之间,平均为73.03%,表明种群间变异是小花山桃草表型变异的主要来源。不同性状对环境变化的反应不同,其中株高、茎粗、单株果数和比叶面积在种群内的差异不显著,而在种群间的差异达到极显著水平,表型分化系数达82%以上;节间距、叶宽、主根长、分枝数、果长和果宽在种群间和种群内的差异均达极显著水平;单果种子数和单果重在种群内和种群间的差异均不显著。株高、茎粗、叶长、叶宽、茎重、叶重、主根重和单株果数表现出一致的协变格局,生理功能性状之间的这种整合特性有助于小花山桃草适应多样的生境。聚类分析显示,5个种群可按生境条件的好坏分为两大类,进一步表明小花山桃草的表型特征受种群间环境条件(水、肥)强烈影响。绝大多数表型性状与生境因子存在显著或极显著的相关关系,但果实性状(包括果宽、单果重和单果种子数)与生境因子相关性低,进一步表明繁殖性状不易受环境条件影响。  相似文献   
12.
CASE HISTORY A 21-year-old male sulphur-crested cockatoo (Cacatua galerita) was presented following the sudden appearance of blood associated with the passage of faeces and urates.

CLINICAL AND PATHOLOGICAL FINDINGS: There was fresh blood-staining of the feathers around the vent. The dorsal mucosal wall of the proctodeum was erythematous and roughened in appearance. An endoscopic biopsy was performed, and histological examination revealed multiple fronds of epithelium; the mucosa varied from simple to pseudostratified columnar epithelium, with diffuse hyperplasia of goblet cells. The underlying connective tissue stroma was well vascularised and was infiltrated with mixed inflammatory cells, comprising granulocytic cells and macrophages. PCR testing for both herpesvirus and papillomavirus, using consensus primers, was negative.

DIAGNOSIS: Cloacal papillomatosis.

CLINICAL RELEVANCE: This case manifested typical clinical signs and histological lesions of cloacal papillomatosis in the absence of demonstrable herpesvirus or papillomavirus. Veterinarians need to consider this disease in the differential diagnosis of blood in the droppings of parrots and cockatoos even in countries where psittacine herpesviruses are exotic diseases.  相似文献   
13.
为了解合肥市公园植物群落物种组成现状,通过样方法对合肥市包河公园、银河公园、杏花公园和古逍遥津4个城市公园的园林陆生植物进行了植物多样性分析。研究结果表明:(1)合肥市城市公园中共有园林植物70科140属152种,其中蔷薇科、禾本科、菊科等在合肥市公园应用较多;在属的地理分布类型上,合肥市园林植物以温带地理分布为主,温带性分布77属,占总属数的55%。(2)乔、灌、草植物种类比约为1: 0.67:1.22。乔木层中常绿和落叶比约为1:1.75,灌木层中常绿和落叶比约为1: 0.68,草本层中一、二年生草本与多年生草本比为1: 2.05;乔木层优势种依次为棕榈(Trachycarpus fortunei )、香樟(Cinnamomum camphora )、女贞(Ligustrum lucidum)、桂花(Osmanthus fragrans)等,灌木层优势种为十大功劳(Mahonia fortunei)和锦绣杜鹃(Rhododendron pulchrum ),草本层优势种为沿阶草(Ophiopogon bodinieri)。(3)合肥市园林植物中共发现外来植物22科39属40种,入侵植物13科26属27种,其中入侵菊科植物最多(7种),其次为禾本科(5种)。(4)合肥市公园物种丰富度表现为草本层>乔木层>灌木层,Simpson多样性指数、Shannon-Wiener多样性指数和Pielou均匀度指数表现为乔木层>灌木层>草本层的分布规律。该研究可为合肥城市公园植物选择及群落结构优化提供理论依据。  相似文献   
14.
为了预防外来浮游植物入侵引发的渤海湾赤潮灾害,基于近20年建设项目环境影响评价报告书和相关文献资料的研究成果,收集整理了渤海湾海域已发现的外来浮游植物物种及具体物种信息,分析了物种入侵的主要途径及可能产生的赤潮灾害影响。结果表明:渤海湾海域共发现17种外来浮游植物,其中,甲藻门最多,有10种;硅藻门次之,有5种;金藻门和黄藻门最少,各有1种。研究表明:渤海湾外来浮游植物中,除中华盒形藻外,其余16种均属于赤潮生物,这些物种主要通过压载水引入、传播的方式进入渤海湾海域,应加强港口监控和管理,以防赤潮灾害。  相似文献   
15.
外来入侵种及其对森林生态系统的威胁:概念和对策   总被引:12,自引:1,他引:12  
外来入侵种问题越来越受到关注,其对经济、人类生活、环境和生物多样性的危害也被广泛认识。结合介绍外来入侵种的定义、危害性和入侵过程,对入侵种的生物学特征、易受入侵种危害的生态系统的特征和控制措施进行了归纳;结合国内外研究和管理现状,对我国的外来入侵种研究和管理对策提出了具体建议。  相似文献   
16.
ObjectiveTo compare between blind and smartphone-based endoscope-assisted techniques for endotracheal intubation in rabbits.Study designProspective clinical study.AnimalsA total of 34 rabbits.MethodsRabbits were assigned to four groups: intubation by a veterinary anesthesiologist (VA) or an exotic pet medicine specialist (EPS) using blind or endoscope-assisted techniques. Propofol dose, number of attempts until successful intubation, total time for intubation, duration of the successful attempt and occurrence of lingual cyanosis/laryngeal lesions were recorded. Data were analyzed by t test, Wilcoxon–Mann–Whitney U test or chi-square test. Pearson correlation for body weight was performed.ResultsThe success rate of blind intubation was 88.9% and 77.8% for VA and EPS, respectively. Propofol dose, total and median number of attempts, total time for intubation and duration of the successful attempt were 3.1 (0–6.2) mg kg–1, 19, 2 (1–5), 79 ± 65 and 30 ± 20 seconds for VA and 1.5 (0–4.5) mg kg–1, 24, 3 (1–5), 136 ± 92 and 38 ± 16 seconds for EPS. The success rate of endoscope-assisted intubation was 87.5% for both operators. Propofol dose, total and median number of attempts, total time for intubation and duration of the successful attempt were 2.5 (1.3–7.4) mg kg–1, 22, 3 (1–5), 170 (65–368) and 46 (22–150) seconds for VA and 3.2 (0–6) mg kg–1, 11, 1 (1–4), 56 (27–432) and 55 (26–79) seconds for EPS. VA performed blind intubation more quickly, propofol dose was lower and cyanosis was less frequent than in the endoscope-assisted group.Conclusions and clinical relevanceBoth techniques were reliable for rabbit endotracheal intubation. Best results were achieved when the operator was experienced in the technique. The smartphone-based endoscope is a useful aid for rabbit intubation.  相似文献   
17.
榆林沙区自然环境恶劣,植被稀少。因此在生态环境建设中不仅要应用乡土树种,还要引进外来优良树种,以丰富榆林市的树木资源,使绿化达到更完美的效果。而如何将乡土树种与外来树种协调应用是关键所在。只有在保护好乡土树种资源的同时,有原则、有目标、有步骤地进行引种,使之不发生生物入侵,才是正确的培育措施。  相似文献   
18.
  • 1. Recreational shore fishing along the coast of the marine reserve of Cap de Creus (NW Mediterranean) was studied in 2007 and 2009 based on roving creel surveys (on‐site angler surveys during which anglers' harvests are examined by the survey clerk). The study aimed to assess the biological impacts of this leisure activity on coastal fish stocks and the potential risks arising from the use of exotic baits.
  • 2. Recreational shore fishers employ seven different fishing techniques, of which the bottom fishing rod (a fishing rod whose hooks, together with the bait, lie on the bottom or near it by means of a heavy weight) is by far the most widely used method (nearly 90% of observations). In total, 25 fish species were identified in the catch from the bottom fishing rod.
  • 3. The estimated annual shore fishing catches (c.3 tons) are much lower than those obtained by recreational boat and spear fishing (c.20 tons each), and those from commercial (artisanal) fishing (c.50 tons). The weighted mean vulnerability index and trophic level values in the catch from the bottom fishing rod are 52.2 and 4.03, respectively.
  • 4. A minimum of 43% of the baits used by the shore anglers were live, non‐native species (mostly polychaetes).
  • 5. Overall, results highlight the impact of shore angling on coastal fish communities of a protected area and the increasing environmental risks arising from the use of exotic marine baits, which constitute a potential and unregulated vector of introduction of non‐native species in the Mediterranean. Copyright © 2011 John Wiley & Sons, Ltd.
  相似文献   
19.
Live food items are often fed to exotic pet species whether they are birds, amphibians, reptiles, or mammals. This raises issues of welfare, both of the animals fed live prey items and the prey itself. Concerns over live food welfare are particularly marked in the feeding of vertebrate prey items and evidence presented here shows the prolonged time taken for rodents to die. However, the welfare of all exotic pets relies both on providing optimal nutrition to the predator and ensuring, as much as possible, that their natural behaviours can be expressed. Does that mean that predatory species must be fed live prey? This article discusses this problem and seeks potential solutions.  相似文献   
20.
1. Development of effective conservation strategies for freshwater biodiversity must take account of the trade‐off between species preservation and human use of ecosystem goods and services. The latter cannot be prevented, and attempts to manage ecosystems that focus solely on maximizing biodiversity will fail. 2. A compromise position of management for ecosystem functioning and human livelihoods — rather than preservation of every species — will provide a better basis for biodiversity conservation. This has implications for the management of exotic species. 3. There are some situations, in lentic habitats in Sri Lanka, for example, where the establishment of exotics has increased fishery yields without apparent detriment to native biodiversity. The Sepik River in Papua New Guinea provides another illustration of potential compromises between human livelihoods and biodiversity conservation. 4. The Sepik supports a relatively unproductive fishery. Two fish stocking projects (in 1987–93 and 1993–97), representing a partnership between the Papua New Guinea Government and the United Nations (UNDP/FAO), led to the introduction of a suite of exotic fish into the Sepik. Species were selected on the basis of their potential to occupy niches not filled by native fish. Unfortunately, the outcomes of these introductions are poorly documented, although there is preliminary evidence both of increased human use of exotic fish as well as declines of some native species associated with the spread of exotics. 5. Better understanding of the results of the Sepik fish introductions is important, because the pressures of burgeoning human populations in most of tropical Asia make it impossible to preserve near‐pristine environments such as the Sepik. While attempts to conserve natural or near‐natural systems must remain a priority, there is a need to develop strategies for the management of damaged or degraded ecosystems, which may contain exotics, with the aim of maintaining ecosystem functioning and, if possible, maximizing the persistence of native biodiversity. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
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