Increases and decreases in network synchrony associated with local population extinction and recolonization

2013 ◽  
Vol 266 ◽  
pp. 68-72 ◽  
Author(s):  
Stephen F. Matter
Keyword(s):  
Local Population ◽  
Population Extinction ◽  
Network Synchrony

scholarly journals Lagoon Resident Fish Species of Conservation Interest According to the Habitat Directive (92/43/CEE): A Review on Their Potential Use as Ecological Indicator Species

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2059 ◽  
Author(s):  
Chiara Facca ◽  
Francesco Cavraro ◽  
Piero Franzoi ◽  
Stefano Malavasi
Keyword(s):  
Life Cycle ◽  
Fish Species ◽  
Coastal Lagoon ◽  
Salt Marshes ◽  
Coastal Lagoons ◽  
Conservation Status ◽  
Local Population ◽  
Ecological Indicator ◽  
Habitat Directive ◽  
Population Extinction

Transitional waters are fragile ecosystems with high ecological, social and economic values, that undergo numerous threats. According to the information provided by European Member States in the framework of the European Directive 92/43/EEC (Habitat Directive), the main threat to these ecosystems is represented by morphological and hydrological changes. The present work focuses on six lagoon fish species included in the Habitat Directive annex II (species requiring conservation measures: Aphanius fasciatus, A. iberus, Knipowitschia panizzae, Ninnigobius canestrinii, Valencia hispanica and V. letourneuxi) that spend their entire life cycle in the Mediterranean priority habitat 1150* “Coastal lagoons”. The overview of the current scientific literature allowed us to highlight how the presence and abundance of these species may provide important indications on the conservation status of coastal lagoon habitats. In fact, their occurrence, distribution and biology depend on the presence of peculiar structures, such as salt marshes, small channels, isolated pools and oligohaline areas. Coastal lagoon fragmentation and habitat loss have led to a significant reduction in genetic diversity or local population extinction. Although Aphanius and gobies have been shown to survive in eutrophic environments, it is clear that they cannot complete their life cycle without salt marshes (mainly Aphanius) and wetland areas (mainly gobies).

scholarly journals Risk of local extinction and genetic diversity of Melipona quadrifasciata (Apidae: Meliponini) in a possible Northeastern limit of its distribution in Brazil

Sociobiology ◽  
2016 ◽  
Vol 63 (2) ◽  
pp. 804 ◽  
Author(s):  
Edilson D Araújo ◽  
Rosane Gomes Oliveira ◽  
Higor Cesar Meneses Calazans ◽  
Carina Caroline Silva França ◽  
Valdson SANTOS ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Analysis ◽  
Local Population ◽  
Rapid Loss ◽  
Unique Haplotype ◽  
Population Extinction ◽  
Nesting Site ◽  
Disjunct Populations ◽  
Eusocial Bees ◽  
Issr Primers

Rapid loss of genetic diversity among eusocial bees, and extinction of their local population has become a major world concern. Populations of M. quadrifasciata have increasingly declined due to predatory extractivism and destruction of their habitat. Knowledge of their local population could give insights on the strategies for monitoring and conservation of this species. In this study, initially, 14 colonies (140 workers) from the Northern limit of the Northeastern sandbank of the Atlantic Forest were analyzed employing geometric morphometrics techniques. Then the cytochrome b gene sequences and ISSR primers were utilized for molecular analysis. The results were compared with the results of 30 M. quadrifasciata colonies (300 workers) found in the semiarid Caatinga region. The morphometrics and the molecular analysis suggested the formation of disjunct populations between the studied geographical zones. All the 14 colonies analyzed from the river São Francisco region were found on the Southern margin of the river São Francisco and they all belonged to one single haplotype. No colonies were found on the Northern bank of the river. We suggest that the river São Francisco is an effective georgraphical barrier for the distribution of this species and propose an urgent need for the development of a conservation program for the population of M. quadrifasciata as it represents a unique haplotype in the region. Also their nesting habit exclusively in the diseased coconut trees which probably will be replaced by new trees, create the risk of population extinction due to the lack of nesting site.

Metapopulations and their spatial dynamics

2007 ◽  
Author(s):  
Sean Nee
Keyword(s):  
Local Population ◽  
Spatial Dynamics ◽  
Suitable Habitat ◽  
Dynamical Process ◽  
Demographic Stochasticity ◽  
Population Extinction ◽  
Local Populations ◽  
Preferred Habitat ◽  
Tree Falls

The study of metapopulation dynamics has had a profound impact on our understanding of how species relate to their habitats. A natural, if naïve, set of assumptions would be that species are to be found wherever there is suitable habitat that they can get to; that species will rarely, if ever, be found in unsuitable habitat; that they will be most abundant in their preferred habitat; that species can be preserved as long as a good-size chunk of suitable habitat is conserved for them; and that destruction of a species’ habitat is always detrimental for its abundance. We will see that none of these reasonable-sounding assumptions is necessarily true. Metapopulation biology is a vast field, so to focus this chapter I will be guided partly by questions relevant to conservation biology. There are two important kinds of metapopulation. The so-called Levins metapopulation idea (Levins, 1970) is illustrated in Figure 4.1. It is imagined that patches of habitat suitable for a species are distributed across a landscape. Over time, there is a dynamical process of colonization and extinction: the colonization of empty patches by occupied patches sending out colonizing propagules and the extinction of local populations on occupied patches. This extinction can occur for a number of reasons. Small populations are prone to extinction just by the chance vagaries of the environment, reproduction, and death—environmental and demographic stochasticity (May, 1974b; Lande et al., 2003). An example of a species for which this is important is the Glanville fritillary butterfly (Melitaea cinxia), which has been extensively studied by Hanski and colleagues (Hanski, 1999). This Scandinavian butterfly lives in dry meadows which are small and patchily distributed. Another reason for local population extinction is that the habitat patch itself may be ephemeral. For example, wood-rotting fungi will find that their patch ultimately rots completely away (Siitonen et al., 2005) and epiphytic mosses will ultimately find that their tree falls over (Snall et al., 2005). The second type of metapopulation consists of local populations connected by dispersal, but without the extinction of the local populations.

scholarly journals Habitat fragmentation compromises the population dynamic of the globally near-threatened Straight-billed Reedhaunter (Limnoctites rectirostris)

2018 ◽  
Author(s):  
Maycon S. S. Gonçalves ◽  
Priscila S. Pons ◽  
Felipe C. Bonow ◽  
Vinicius A. G. Bastazini ◽  
José A. Gil-Delgado ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Local Population ◽  
Water Reservoir ◽  
Theoretic Approach ◽  
Patch Occupancy ◽  
Entire Study ◽  
Information Theoretic ◽  
Population Extinction ◽  
Occupancy Patterns ◽  
Information Theoretic Approach

AbstractUnderstanding the consequences of habitat fragmentation to biological populations is crucial to develop sound conservation polices. The Straight-billed Reedhaunter (Limnoctites rectirostris) is a little known and threatened Passeriform that is highly dependent Erygo wetlands patches. Here, we evaluated the effects of habitat fragmentation on populations of the Straight-billed Reedhaunter, during the construction of a water reservoir in southern Brazil. During eight months, we monitored five Eryngo wetlands patches occupied (n=3) and no occupied (n=2) by Straight-billed Reedhaunter individuals, collecting data on their temporal occupancy patterns and registering new fragmentation events in formally continuous habitat patches. We evaluated the consequences of habitat fragmentation on the probabilities of patch occupancy, colonization and extinction of populations of the Straight-billed Reedhaunter using an information-theoretic approach. Out of the three patches occupied by Straight-billed Reedhaunter, two were not altered by construction activities and their populations were present during the entire study period. After fragmentation events, local extinction in one of the wetland patches was observed, and individuals were sporadically observed in two other initially unoccupied sites. The model in which fragmentation affected only the extinction probability was the most plausible among the set of candidate models. Fragmentation greatly increased the chance of local population extinction within patches. Our results indicate that the conservation of populations of the Straight-billed Reedhaunter is highly dependent on continuous and unaltered wetland patches.

Effects of dispersal on local population increase

2000 ◽  
Vol 3 (6) ◽  
pp. 479-482 ◽  
Author(s):  
J.M. Kean ◽  
N.D. Barlow
Keyword(s):  
Local Population ◽  
Population Increase

Understanding trust between military organizations and a local population

2010 ◽  
Author(s):  
Ritu M. Gill ◽  
Angela R. Febbraro ◽  
Megan M. Thompson
Keyword(s):  
Local Population ◽  
Military Organizations
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