首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 125 毫秒
1.
漩涡模型及其在白鱀豚种群管理中的应用   总被引:2,自引:0,他引:2  
漩涡模型作为一种用于野生动物种群生存力分析的计算机模拟工具,已在濒危物种的保护和管理方面得到了广泛的应用。本文介绍了漩涡模型的产生和特征,同时使用这一模型完成了长江中白鱀豚(Lipotes vexillifer)种群生存力分析。模拟的结果表明,在未来 100年内,白鱀豚在高、中死亡率的条件下,种群灭绝概率分别为1.0和0.5左右。但是,在死亡率低和极低的条件下,白鱀豚的灭绝过程可能持续100年以上,或永远也不会灭绝。开始种群大小对白鱀豚的平均灭绝时间有一定的影响,但对种群生长率(r)却没有影响。在高、中、和低死亡率条件下,白鱀豚种群生长率分别为-0.07、-0.04和-0.02。  相似文献   

2.
空间分析技术在害虫种群管理中的应用   总被引:4,自引:0,他引:4  
翟连荣 《昆虫知识》1997,34(5):314-318
过去几十年,在大范围的害虫防治过程中,关于害虫种群发生规律的研究已经积累了大量田间调查的实验数据和资料。有些是定量的,有些是定性的,有些是已经发表的研究结果,而绝大部分则是没有发表的田间记录和资料。从局部范围看,这些数据和资料无疑对各地的虫情测报起着重要的作用。然而,随着研究工作的深入,对害虫发生的宏观测报提出了更高的要求。人们发现绝大多数危害严重的主要害虫,并非孤立地在若干地区发生。若从较大的区域去观察和分析,可以发现不同地域间害虫的发生有着密切的关联关系。特别是那些活动能力较强的物种,如果只…  相似文献   

3.
鄱阳湖区的獐种群是一个孤立的种群,近年来其数量急剧减少。本研究应用种群生存力分析的原理和方法,利用漩涡模型预测了鄱阳湖区獐种群在未来100 a内的种群变动趋势,并分析了不同场景下獐种群的变化趋势。结果表明:鄱阳湖区獐种群在未来100 a灭绝的概率是0.37。如果鄱阳湖区獐的栖息地进一步被破坏,獐种群的灭绝概率将大幅度增加;高概率的幼仔死亡率会使獐种群在未来100 a出现灭绝的概率为100%;灾害对种群的影响也很大,在洪灾和狩猎的双重作用下,洪灾发生频率增加将使獐种群灭绝概率增大。通过本次对鄱阳湖区獐的种群生存力分析,发现幼仔的死亡率和栖息地的破碎化是鄱阳湖区獐种群的重要制约因素,建议在獐栖息地之间设立生态走廊,加大对偷猎的打击力度,将有利于该地区獐种群的长期发展。  相似文献   

4.
朱■(Nipponianippon)种群生存力分析   总被引:2,自引:0,他引:2  
到目前为止,只有一个野生朱群体幸存下来,而且它的种群大小自1981年重新发现以来,一直在20只以下波动。本文应用种群生存力分析的方法,借助漩涡模型,根据朱14年的种群数据,总结和预测了其种群动态,并着重研究了朱的濒危程度。结果显示,按过去10余年的生存状况,朱在50年内绝灭的可能性是98.5%,平均绝灭时间为15.72年。现存种群数量很低,所以种群统计随机性对其命运有很大影响。灵敏度分析表明,当前的朱种群对意外死亡和生存环境的波动较为敏感。保护工作的优先项目是对猎杀和天敌的控制以及从各个方面提高朱的生活质量  相似文献   

5.
朱鹮(Nipponia nippon)种群生存力分析   总被引:3,自引:1,他引:3  
到目前为止,只有一个野生朱鹮群体幸存下来,而且它的种群大小自1981年重新发现以来,一直在20只以下波动。本文应用种群生存力分析的方法,借助漩涡模型,根据朱鹮14年的种群数据,总结和预测了其种群动态,并着重研究了朱鹮的濒危程度。结果显示,按过去10余年的生存状况,朱鹮在50年内绝灭的可能性是98.5%,平均绝灭时间为15.72 年。现存种群数量很低,所以种群统计随机性对其命运有很大影响。灵敏度分析表明,当前的朱鹮种群对意外死亡和生存环境的波动较为敏感。保护工作的优先项目是对猎杀和天敌的控制以及从各个方面提高朱鹮的生活质量。  相似文献   

6.
马边大风顶自然保护区大熊猫种群生存力模拟分析   总被引:7,自引:1,他引:7  
采用漩涡模型Vortex mondel 713 , 模拟了马边大风顶自然保护区大熊猫种群在未来100年内的变动趋势。结果显示: 在无交配限制、无密度制约、无近亲交配衰退等条件下, 马边大风顶自然保护区大熊猫种群数量呈下降趋势; 在考虑近交衰退的影响后, 遗传多样性水平降低, 灭绝率提高; 竹子开花虽能加速大熊猫种群的绝灭, 但由于保护区分布有多个竹种,因此并不会对大熊猫种群产生灾难性影响; 但是人为捕杀可迅速减少大熊猫种群数量, 加速其灭绝过程。因此, 对该保护区大熊猫进行保护的最重要措施就是严格控制人为捕杀, 并保护栖息地及走廊带。  相似文献   

7.
Nachman模型在油松毛虫蛹种群简易估计抽样中的应用   总被引:3,自引:1,他引:2  
马占山 《昆虫知识》1991,28(1):24-26
本文将Nachman模型:应用于油松毛虫蛹种群的简易估值抽样中,建立了油松毛虫蛹种群的Nachman简易估计模型,并对此模型的可靠性、估计精度,以及实际应用时的理论抽样数确定等问题进行了探讨  相似文献   

8.
李海洋  丁长青 《四川动物》2013,32(2):313-319
种群生存力分析(population viability analysis,PVA)是濒危物种保护研究的主要方法之一。自PVA提出之后,主要应用于预测濒危物种的灭绝概率。随着PVA软件的产生,其应用范围进一步扩展,甚至出现滥用和误用之例,使其准确性受到质疑。目前,PVA主要应用于濒危物种的保护与管理。本文从保护管理对策的制定与评估、再引入计划的评估和自然保护区设计与管理有效性评估三个方面进行综述;对PVA使用时的数据收集,以及模型的选择、建立和应用等需要注意的问题加以总结;从遗传数据的使用、基于个体的种群模型的发展、近交衰退和降低入侵物种的威胁等方面对PVA的应用提出展望。  相似文献   

9.
以荒漠区人工植被的恢复与重建为背景,从宏观尺度研究了很集合种群的空间分布新模式,建立了基于Levins集合种群模型的数值模拟方法。对两物种的模拟结果表明:在适当选择参数下,模拟植被区的集合种群可以形成“海藻式”稳定的时空分布结构,在理论上表明相同生态特征的物种在空间生境中可以达成共存。为了达到物种丰富度和生产力最佳,实现持续发展,对多物种集合种群进行了模拟。模拟结果显示当物种的种数为5时,空间上随机播种的模拟种群覆盖率达到最大,因而可发挥最大的治沙作用。另外,模拟还显示在播种时应采取集聚式的空间播种模式,以使种群具有较高的防沙能力。该结果可为生物防沙治沙领域提供理论依据。  相似文献   

10.
自然植物种群的亲本分析及其在生态学研究中的应用   总被引:10,自引:0,他引:10  
自然植物种群的结构、交配行为、基因流以及个体和基因型的适合度是种群生物学的重要内容,而种群谱系的建立是综合研究以上内容的重要方法。种群谱系的构建最初是在人类中进行研究的,其统计/遗传学方法在1950年前就已有详尽的研究[1],近些年来用于亲子鉴定也已...  相似文献   

11.
白鱀豚(Lipotesvexillifer)是仅分布于我国长江中下游水域的一种珍稀濒危动物。长江水体污染(如有毒元素等)被认为可能是白鱀豚种群致危的主要因素之一(Yang,1997)。迄今,有关白鱀豚体内微量元素的研究尚很少,只有陆佩洪等(1983)、杨利寿等(1988)曾报道过白鱀豚组织中铁(Fe)、铜(Cu)、锌(Zn)、锰(Mn)、镍(Ni)、铅(Pb)、汞(Hg)和镉(Cd)在某些组织器官中的积累水平。本文对1头饲养条件下白鱀豚“淇淇”体内的必需元素Cu、Zn、锰(Mn)、钼(Mo)、硒(Se)和有毒或非必需元素砷(As)、Cd、铝(Al)的积累特征进行了报道,以期为白豚的保护提供…  相似文献   

12.
Population viability analysis (PVA) has frequently been used in conservation biology to predict extinction rates for threatened or endangered species. In this study, we used VORTEX to model Korean long-tailed goral (Naemorhedus caudatus) using previously collected ecological data. We focused on modelling population extinction, mean population size and heterozygosity. The minimum viable population size was found to be at least 50 gorals for 100 years, regardless of carrying capacity. However, populations with fewer than 50 gorals could not remain successful in the model. Inbreeding depression, catastrophes and supplementation also affected patterns of population extinction, mean population size and heterozygosity. Supplementation with new individuals had the strongest effect on extinction, mean population size and heterozygosity, followed by initial population size, inbreeding, catastrophes and carrying capacity. These results suggest that a supplementation by extra goral individuals from goral proliferation facilities would be the most helpful means for the restoration programme. More Korean goral-specific information regarding demographic and habitat parameters is needed for further PVA of the species.  相似文献   

13.
白(鱼既)豚(Lipotes vexillifer)是仅分布于我国长江中下游水域的一种珍稀濒危动物.长江水体污染(如有毒元素等)被认为可能是白(鱼既)豚种群致危的主要因素之一(Yang,1997).迄今,有关白(鱼既)豚体内微量元素的研究尚很少,只有陆佩洪等(1983)、杨利寿等(1988)曾报道过白(鱼既)豚组织中铁(Fe)、铜 (Cu)、锌 (Zn)、锰 (Mn)、镍(Ni)、铅 (Pb)、汞(Hg)和镉 (Cd)在某些组织器官中的积累水平.本文对1头饲养条件下白(鱼既)豚"淇淇"体内的必需元素Cu、Zn、锰 (Mn)、钼 (Mo)、硒 (Se)和有毒或非必需元素砷 (As)、Cd、铝 (Al)的积累特征进行了报道,以期为白(鱼既)豚的保护提供基础资料.  相似文献   

14.
There is only one population of the crested ibis (Nipponia nippon) surviving in the wild, which has not exceeded 40 individuals since it was rediscovered in 1981. We used detailed data of the annual population size and natality collected by the Crested Ibis Conservation and Observation Station (CICOS) over the past 17years. We were able to obtain a more accurate census of age structure and mortality as all of the fledglings have been identified by leg bands in 1987. Consequently, we analyzed the current state of the crested ibis and predicted its future using Population Viability Analysis (PVA) with the help of the computer simulation model VORTEX (Version 7.2). The results indicated that the extinction probability of the crested ibis was 19.7% in 100years. Sensitivity analysis showed that the extinction probabilities were sensitive to catastrophes and environmental variation, and the long-term existence of the population was dependent on the carrying capacity of the habitat and inbreeding depression. Conservation efforts are critical for the survival of the crested ibis. The prior conservation project involves controlling hunting and predation, as well as improving the life level of these few remnant creatures.  相似文献   

15.
It has been proposed that in slow‐growing vertebrate populations survival generally has a greater influence on population growth than reproduction. Despite many studies cautioning against such generalizations for conservation, wildlife management for slow‐growing populations still often focuses on perturbing survival without careful evaluation as to whether those changes are likely or feasible. Here, we evaluate the relative importance of reproduction and survival for the conservation of two bottlenose dolphin (Tursiops cf aduncus) populations: a large, apparently stable population and a smaller one that is forecast to decline. We also assessed the feasibility and effectiveness of wildlife management objectives aimed at boosting either reproduction or survival. Consistent with other analytically based elasticity studies, survival had the greatest effect on population trajectories when altering vital rates by equal proportions. However, the findings of our alternative analytical approaches are in stark contrast to commonly used proportional sensitivity analyses and suggest that reproduction is considerably more important. We show that

16.
The agricultural scene has changed over the past decades, resulting in a declining population trend in many species. It is therefore important to determine the factors that the individual species depend on in order to understand their decline. The landscape changes have also resulted in habitat fragmentation, turning once continuous populations into metapopulations. It is thus increasingly important to estimate both the number of individuals it takes to create a genetically viable population and the population trend. Here, population viability analysis and habitat suitability modeling were used to estimate population viability and future prospects across Europe of the Little Owl Athene noctua, a widespread species associated with agricultural landscapes. The results show a high risk of population declines over the coming 100 years, especially toward the north of Europe, whereas populations toward the southeastern part of Europe have a greater probability of persistence. In order to be considered genetically viable, individual populations must count 1,000–30,000 individuals. As Little Owl populations of several countries count <30,000, and many isolated populations in northern Europe count <1,000 individuals, management actions resulting in exchange of individuals between populations or even countries are probably necessary to prevent losing <1% genetic diversity over a 100‐year period. At a continental scale, a habitat suitability analysis suggested Little Owl to be affected positively by increasing temperatures and urban areas, whereas an increased tree cover, an increasing annual rainfall, grassland, and sparsely vegetated areas affect the presence of the owl negatively. However, the low predictive power of the habitat suitability model suggests that habitat suitability might be better explained at a smaller scale.  相似文献   

17.
杨红义  韩瑞 《生态学报》2024,44(9):3984-3998
圆口铜鱼(Coreius guichenoti)是长江上游特有鱼类,研究金沙江梯级水电开发背景下圆口铜鱼种群生存力变化对该物种的保护具有重要意义。Vortex模型在传统种群评估方法的基础上,引入种群年龄结构、繁殖体制、性比等因素,并考虑了环境、灾害、遗传等随机性对种群的影响,可模拟种群数量和生存力变化特征,是一种应用广泛的种群生存力分析模型。基于1981-2021年金沙江圆口铜鱼资源调查数据,采用Vortex模型构建了金沙江中下游干流大规模水电开发前、后两个时期圆口铜鱼种群生存力分析模型,考虑了水电开发下,水温、流速等环境变化对圆口铜鱼种群的影响,对比了两个时期圆口铜鱼种群数量、结构及生存力等。结果表明:水电开发前,严重过度捕捞对圆口铜鱼种群产生了显著威胁,10年内种群数量下降了12.5%,百年内种群内禀增长率为0.085,种群的生存和繁殖能力较稳定,灭绝概率为1%;水电开发后,10年内种群数量下降了42%,百年内种群内禀增长率降至-0.087,灭绝概率增大至36.1%,种群平均灭绝时间为83.7年,圆口铜鱼抵抗环境干扰的种群恢复能力降低,种群生存力受到影响。  相似文献   

18.
S. P. Biswas  S. Boruah 《Hydrobiologia》2000,430(1-3):97-111
There are nearly 200 species of aquatic vertebrates, almost exclusively fishes, in the Brahmaputra River System. This faunal composition includes not only a wide variety of food-fishes, but also about 50 varieties of aquarium fishes. The most spectacular animal in the Brahmaputra is undoubtedly the river dolphin, Platanista gangetica. The population of many species, particularly of the dolphin, is in steady decline. River dolphins, mostly juveniles, often entangle themselves in gill and drift nets, while feeding on trapped fishes. Proper implementation of Indian Fisheries Act, especially a total ban on destructive nets and on killing of brooders and juveniles by explosives and poisoning should be strictly implemented. Poor communication facilities in remote riverbank areas and lack of funds are two important reasons for the slow progress of the conservation of river dolphin and this endangered species is now on the verge of extinction. The anthropogenic activities and their impact on the habitat of river dolphin are discussed.  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