Use of space by bank voles (Clethrionomys glareolus) in a polish farm landscape     

Michŀ Kozakiewicz  Anna Kozakiewicz  Aleksy Łukowski  Tomasz Gortat 《Landscape Ecology》1993,8(1):19-24

Movements of bank voles (Clethrionomys glareolus) were studied in a farmland mosaic in Poland. Distances crossed by animals in short-time periods are significantly longer in heterogenous than in homogenous habitats. In long-time and large-spatial scales, a significant portion of the animals in a population travel among habitat elements of the mosaic, reducing the degree of isolation of patch populations and decreasing the probability of local extinction.  相似文献   

The effects of landscape composition and physiognomy on metapopulation size: the role of corridors   总被引：5，自引：0，他引：5  

Anderson  Greg S.  Danielson  Brent J. 《Landscape Ecology》1997,12(5):261-271

We develop and analyze a model that examines the effects of corridor quality, quantity, and arrangement on metapopulation sizes. These ideas were formerly investigated by Lefkovitch and Fahrig (1985) and Henein and Merriam (1990). Our simulations provide results similar to the Henein and Merriam model, indicating that the quality of corridors in a landscape and their arrangement will influence the size of a metapopulation. We then go one step further, describing how corridor arrangement alters the metapopulation, and provide a method for predicting which corridor arrangements should support larger metapopulations. In contrast to the Henein and Merriam model, we find that the number of corridor connections has no influence on the size of a metapopulation in a landscape unless there is an accompanying change in the uniformity of the distribution of corridor connections among patches.  相似文献   

Metapopulation theory and habitat fragmentation: a review of holarctic breeding bird studies   总被引：15，自引：0，他引：15  

Paul Opdam 《Landscape Ecology》1991,5(2):93-106

Metapopulations are conceived as spatially structured populations consisting of distinct units (subpopulations), separated by space or barriers, and connected by dispersal movements. Metapopulations characteristically demonstrate a turnover of local populations going extinct and becoming re-established, resulting in a distribution pattern that shifts over time. Metapopulation theory is used to analyse the effects of habitat fragmentation on birds in the temperate zone, integrating various explanations for the paucity of species in isolated ecotopes.There is some evidence that turnover of local populations occurs in fragmented systems. A few studies based on time series demonstrate the local extinction rate to be related to the size of the habitat fragment, whereas the recolonization rate depends on the degree of isolation. Most evidence comes from short-term pattern studies in which the probability of occurrence was found to depend on the size of habitat fragments, on their relative position in the landscape and on the density of corridors lowering the landscape resistance. These data are consistent with predictions from metapopulation theory. However, almost all investigations consider wood fragmentation in agricultural landscapes, and there is a great need for studies in naturally fragmented landscapes as well as for studies focussing on other, less predictable, habitat types.  相似文献   

基于复合种群的阿根廷滑柔鱼资源评估和管理策略评价   总被引：3，自引：2，他引：1  

李娜  陈新军  金岳 《上海海洋大学学报》2019,28(3):471-482

以西南大西洋阿根廷滑柔鱼为例,利用基于贝叶斯统计方法的Schaefer模型分单一种群和复合种群2种种群方案,对其资源量进行评估,并对其管理策略做了风险分析。研究表明,年渔获量数据和资源丰度指数数据为贝叶斯资源评估模型提供了足够多的信息。单一种群方案和复合种群方案下的模型参数的预测值及估算的最大可持续产量接近,单一种群方案下的捕捞死亡率低于限制参考点F_(lim),复合种群方案下的南部种群存在捕捞死亡率大于限制参考点F_(lim)的年份,但随着捕捞死亡率的减小资源量恢复到良好水平。决策分析表明,在单一种群方案和复合种群方案下,当收获率设定为0.3及以下时,资源能够保持在可持续利用的良好水平,保守的管理策略可将收获率设定在0.2至0.3,相应的持续渔获量为80万t左右。  相似文献   

Exploring connectivity between spawning and nursery areas of Mullus barbatus (L., 1758) in the Mediterranean through a dispersal model          下载免费PDF全文

Francesco Gargano  Germana Garofalo  Fabio Fiorentino 《Fisheries Oceanography》2017,26(4):476-497

Connectivity between spawning and nursery areas plays a major role in determining the spatial structure of fish populations and the boundaries of stock units. Here, the potential effects of surface current on a red mullet population in the Central Mediterranean were simulated using a physical oceanographic model. Red mullet larvae were represented as Lagrangian drifters released in known spawning areas of the Strait of Sicily (SoS), which represents one of the most productive demersal fishing‐grounds of the Mediterranean. To consider the effect of inter‐annual variability of oceanographic patterns, numerical simulations were performed for the spawning seasons from 1999 to 2012. The main goal was to explore connectivity between population subunits, in terms of spawning and nursery areas, inhabiting the northern (Sicilian‐Maltese) and southern (African) continental shelves of the SoS. The numerical simulations revealed a certain degree of connectivity between the Sicilian–Maltese and the African sides of the SoS. Connectivity is present in both directions, but it is stronger from the Sicilian–Maltese spawning areas to the African nurseries owing to the marine circulation features of the region. However, because the majority of the larvae are transported to areas unsuitable for settlement or outside the SoS, the dispersal process is characterized by a strong loss of potential settlers born in the spawning areas. These results are in agreement with the low genetic heterogeneity reported for this species in the Mediterranean Sea and support the existence of a metapopulation structure of red mullet in the SoS and the adjacent areas.  相似文献   

The integration of climate change,spatial dynamics,and habitat fragmentation: A conceptual overview          下载免费PDF全文

Marcel HOLYOAK  Sacha K. HEATH 《Integrative zoology》2016,11(1):40-59

A growing number of studies have looked at how climate change alters the effects of habitat fragmentation and degradation on both single and multiple species; some raise concern that biodiversity loss and its effects will be exacerbated. The published literature on spatial dynamics (such as dispersal and metapopulation dynamics), habitat fragmentation and climate change requires synthesis and a conceptual framework to simplify thinking. We propose a framework that integrates how climate change affects spatial population dynamics and the effects of habitat fragmentation in terms of: (i) habitat quality, quantity and distribution; (ii) habitat connectivity; and (iii) the dynamics of habitat itself. We use the framework to categorize existing autecological studies and investigate how each is affected by anthropogenic climate change. It is clear that a changing climate produces changes in the geographic distribution of climatic conditions, and the amount and quality of habitat. The most thorough published studies show how such changes impact metapopulation persistence, source–sink dynamics, changes in species' geographic range and community composition. Climate‐related changes in movement behavior and quantity, quality and distribution of habitat have also produced empirical changes in habitat connectivity for some species. An underexplored area is how habitat dynamics that are driven by climatic processes will affect species that live in dynamic habitats. We end our discussion by suggesting ways to improve current attempts to integrate climate change, spatial population dynamics and habitat fragmentation effects, and suggest distinct areas of study that might provide opportunities for more fully integrative work  相似文献   

Scale‐dependent effects of isolation on seasonal patch colonisation by two Neotropical freshwater fishes     

Jerry Penha  Karlo Y. P. Hakamada  James E. Hines  James D. Nichols 《Ecology of Freshwater Fish》2019,28(2):274-284

The metapopulation paradigm has been central to improve the conservation and management of natural populations. However, despite the large number of studies on metapopulation dynamics, the overall support for the relationships on which the paradigm is based has not been strong. Here, we studied the occupancy dynamics of two Neotropical fishes (i.e., Pimelodella gracilis and Leporinus friderici) to investigate two fundamental premises of the metapopulation paradigm, that is, that isolation and area/habitat quality affect colonisation and extinction probabilities in predictable ways. In order to do this, we used a modification of occupancy models that allows modelling the probability of a site's occupancy as a function of the occupancy of its neighbourhood. We found a weak positive effect of neighbourhood occupancy on P. gracilis colonisation, which is consistent with the propagule rain metapopulation, that is, colonists arriving from outside the studied system. However, we found a strong negative neighbourhood effect on extinction probability, suggesting that declining populations from stream sections are rescued from extinction by neighbouring patches. In contrast, the effect of neighbourhood occupancy on the metapopulation dynamics of L. friderici was in the opposite direction, affecting positively colonisation but not affecting extinction rates, which is consistent with the classical metapopulation model. In addition, the occupancy dynamics of both species were affected by water velocity. To our knowledge, this is the first study to link directly dispersal to local population dynamics in Neotropical fishes, and one of the few studies doing inferences on spatial population dynamics based on direct estimates of neighbourhood occupancy.  相似文献   

Indirect connectivity estimates of amphibian breeding wetlands from spatially explicit occupancy models     

George C. Brooks  Jennifer A. Smith  Emmanuel A. Frimpong  Thomas A. Gorman  Houston C. Chandler  Carola A. Haas 《水产资源保护:海洋与淡水生态系统》2019,29(11):1815-1825

Conserving a subpopulation of the northern Atlantic cod metapopulation with a marine protected area     

Liuming Hu  Joseph S. Wroblewski 《水产资源保护:海洋与淡水生态系统》2009,19(2):178-193

• 1. Marine reserves can play an important role in the conservation of subpopulations of marine fish metapopulations. The population spatial structure of northern Atlantic cod of Newfoundland and Labrador has characteristics of a metapopulation. Subpopulations of northern Atlantic cod on the continental shelf were decimated by decades of overfishing, and have not recovered. The remaining northern cod are concentrated in coastal areas.
• 2. A Marine Protected Area (MPA) was established in Gilbert Bay, Labrador by the Government of Canada in 2005 to protect the bay's resident subpopulation of northern Atlantic cod. Conservation of Gilbert Bay cod will help protect the genetic diversity of the northern cod metapopulation.
• 3. Unlike some other MPAs, Gilbert Bay is not a harvest refugium or ‘no‐take’ reserve. Aboriginal subsistence fisheries for salmonids with a bycatch of cod are allowed in designated areas of the MPA. A recreational fishery for Atlantic cod by angling open to all people is under consideration. Management of the MPA must ensure that fishing activities do not endanger the local cod population.
• 4. The population dynamics of Gilbert Bay cod were simulated using an age‐structured Leslie matrix model to estimate the total mortality under various recreational fishing scenarios. The level of sustainable harvest by a recreational fishery depends on the natural mortality of the Gilbert Bay cod population, which is unknown. Therefore, there is risk in permitting a recreational fishery in the MPA.
• 5. There may be benefits to the northern cod metapopulation, if the Gilbert Bay subpopulation is allowed to rebuild to the carrying capacity of the bay. If the abundance of Gilbert Bay cod exceeds the level which the local marine ecosystem can support, some cod may emigrate from the bay and recolonize adjacent coastal areas. The potential for Gilbert Bay cod to recolonize continental shelf areas is less certain.

Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

Spatial dynamics of beetles living on exposed riverine sediments in the upper River Severn: method development and preliminary results     

A.J. Bates  J.P. Sadler  A.P. Fowles  C.R. Butcher 《水产资源保护:海洋与淡水生态系统》2005,15(2):159-174

• 1. Exposed riverine sediments (ERS) are habitats for a large number of rare and specialized invertebrates and, as such, are of considerable conservation importance. Actions that threaten ERS specialists operate on a variety of scales and include river engineering, flow regulation and livestock damage. Populations of specific species of ERS specialist beetles are likely to exhibit individual responses to these threats, depending on the spatial structure and dynamics of the population. An understanding of the spatial dynamics of ERS specialist beetles is, therefore, essential if conservation initiatives are to be successful.
• 2. A mark–recapture experiment was used to investigate the spatial dynamics of beetles on a section of the upper River Severn, mid‐Wales, during June and August 2002. Two species of carabid, Bembidion atrocaeruleum Stephens and Bembidion decorum (Zenker), and one elaterid, Fleutiauxellus maritimus (Curtis), were individually marked and released on one of nine discrete patches of ERS demonstrating a range of patch size, sediment size, habitat heterogeneity, degree of shading, vegetation cover and grazing intensity. The methods used to trap, handle and individually mark beetles were all found to be suitable.
• 3. Population size of B. atrocaeruleum was mainly determined by ERS patch size, suggesting that, in contrast to F. maritimus, this species used all ERS microhabitats.
• 4. During the June study, 5.7% of marked and recaptured B. atrocaeruleum and 10% of marked and recaptured B. decorum actively moved between ERS patches over water or through thick vegetation in both upstream and downstream directions. Inter‐patch movements of >65 m for B. atrocaeruleum and >135 m for B. decorum were detected. Movement rates in August were lower. F. maritimus showed no evidence of inter‐patch movement.
• 5. The lower rate of dispersal and more specific habitat requirements are postulated as reasons for the greater rarity of F. maritimus.

Copyright © 2004 John Wiley & Sons, Ltd.  相似文献