Metapopulations and their spatial dynamics

Author(s):  
Sean Nee

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.

Author(s):  
K. Kumagai ◽  
Y. Kameda

Abstract. In Japan, population decline is one of the important issues that need to be tackled in socioeconomic fields. We apply an analysis method composed of a spatial autocorrelation analysis to the local population data generated through the 1995 and 2015 national census, and try to detect their spatial dynamics in this study. Through making experimental verification of the distance parameter of the spatial autocorrelation analysis, we newly define 2 indices with respect to the size and area where lower local populations are distributed in urbanized areas. It is shown that the local population dynamics are described by the difference of the 2 indices among 1995 and 2015. The expansion of areas where local population decline occurred seems to be detected by our proposed approach.


Author(s):  
Andrew Bednarski ◽  
Gemma Tully

Epigraphers and archaeologists working in Egypt must navigate a host of complex relationships both on and off site. This chapter explores the multifaceted nature of local Egyptian peoples’ relationships with nearby monuments through the lens of a single case study: the site of Sheikh Abd al-Qurna and its local population, the Qurnawi. Egyptologists have not traditionally sought to incorporate formally the stories and histories of local populations in their studies of pharaonic sites. An increasing blend of social awareness and the desire for social action on the part of both foreign professionals and local activists, however, is pushing Egyptologists to re-evaluate their practices, which, in turn, is moving the discipline in new and positive directions.


Oryx ◽  
2018 ◽  
Vol 53 (4) ◽  
pp. 752-756 ◽  
Author(s):  
Cristina Mata ◽  
Nicolás Fuentes-Allende ◽  
Juan E. Malo ◽  
André Vielma ◽  
Benito A. González

AbstractProtected areas help to decrease human impacts on threatened mammals but do not always include species’ core habitats. Here we focus on the Vulnerable taruka Hippocamelus antisensis near the Atacama Desert, Chile, a population that is mainly threatened by interactions with local human communities. We develop a species distribution model for taruka and assess the contribution of protected areas to safeguarding its preferred habitat. From sightings (collected during 2004–2015), absence records (collected in 2014), and environmental variables, we determined that taruka habitat is scarce, highly fragmented and limited to humid areas. Only 7.7–11.2% of the taruka's core habitat is under protection. We recommend the establishment of a protected area in the south of Arica-Parinacota district, an area without settlements that lies within the taruka's core habitat, along with educational programmes, fencing of crops, and inclusion of communities in decision-making in areas where farmer–taruka interactions are negative.


2019 ◽  
Vol 40 (2) ◽  
pp. 177-184
Author(s):  
Nadjat Medjati ◽  
Okkacha Hasnaoui ◽  
Brahim Babali ◽  
Noria Hachemi

The ethnobotanical potentials of Chamaerops humilis in the Béni Snous region (south-west of Tlemcen, western Algeria) has been studied to know the therapeutic utilities and the practices of the local populations, in order to valorize this resource. A series of ethnobotanical surveys were carried out using a questionnaire on the 3 municipalities of Beni Snous (Beni Bahdel, Azail, and Beni Snous). The frequency of use of Chamaerops humilis in the region of study is closely related to the profile of the investigated people. The results of this study reveal that Chamaerops humilis parts are used for therapeutic purposes by the local population: the heart of stipe as to treat dyspepsia (gastrointestinal attacks, 93.90%), fruits as an antiseptic (70.73%), roots for anemia (36.55%) and intestinal worms (30.10%), while the leaves are often used to treat diabetes (21.62%) and other gastrointestinal disorders (30.1%).


Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2059 ◽  
Author(s):  
Chiara Facca ◽  
Francesco Cavraro ◽  
Piero Franzoi ◽  
Stefano Malavasi

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).


Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 233 ◽  
Author(s):  
Keiko Kitamura ◽  
Kentaro Uchiyama ◽  
Saneyoshi Ueno ◽  
Wataru Ishizuka ◽  
Ikutaro Tsuyama ◽  
...  

Research Highlights: We detected the longitudinal gradients of genetic diversity parameters, such as the number of alleles, effective number of alleles, heterozygosity, and inbreeding coefficient, and found that these might be attributable to climatic conditions, such as temperature and snow depth. Background and Objectives: Genetic diversity among local populations of a plant species at its distributional margin has long been of interest in ecological genetics. Populations at the distribution center grow well in favorable conditions, but those at the range margins are exposed to unfavorable environments, and the environmental conditions at establishment sites might reflect the genetic diversity of local populations. This is known as the central-marginal hypothesis in which marginal populations show lower genetic variation and higher differentiation than in central populations. In addition, genetic variation in a local population is influenced by phylogenetic constraints and the population history of selection under environmental constraints. In this study, we investigated this hypothesis in relation to Abies sachalinensis, a major conifer species in Hokkaido. Materials and Methods: A total of 1189 trees from 25 natural populations were analyzed using 19 EST-SSR loci. Results: The eastern populations, namely, those in the species distribution center, showed greater genetic diversity than did the western peripheral populations. Another important finding is that the southwestern marginal populations were genetically differentiated from the other populations. Conclusions: These differences might be due to genetic drift in the small and isolated populations at the range margin. Therefore, our results indicated that the central-marginal hypothesis held true for the southernmost A. sachalinensis populations in Hokkaido.


Author(s):  
Matvey Kulakov ◽  
E.Ya. Frisman

The paper proposed a mathematical model for spatio-temporal dynamics of two-age populations coupled by migration living on a two-dimensional areal. The model equation is a system of nonlocal coupled two-dimensional maps. We considered cases when populations are coupled in a certain neighborhood of different form: circle, square or rhombus. Special attention is paid to the situation when the intensity of the migrants flow between the territories decreases with increasing distance between them. For this model we study the conditions for the formation of groups of synchronous populations or clusters that form, in space, typical structures like spots or stripes mixed with solitary states. It is shown that the dynamics, in time, of different clusters may differ significantly and may not be coherent and correspond to several simultaneous multistable regimes or potential states of the local population. Such spatio-temporal regimes are forced and are caused by impacts or perturbations on a single or several populations when their number falls into the attraction basin of another regime. With strong coupling, such clusters are rare and are represented by single outbursts or solitary states. However, the decrease in the coupling strength leads to the fact that these outbursts cause oscillations of their neighbors, and in their neighborhood a cluster of solitary states is formed which is surrounded by subpopulations with a different type of dynamics. It was found that the interaction of different type of clusters leads to the formation of a large number of groups with transitional dynamics that were not described for local populations.


2021 ◽  
Vol 63 (4) ◽  
pp. 308-316
Author(s):  
Sergiy Boiko

Abstract Changes that occur on the local level can explain the processes on the population level and, at the same time, are the driving force of species adaptation. This manuscript reports data about genetic diversities of the fungus Schizophyllum commune on the level of a local population. Objects of the study were dicarious cultures of S. commune collected from 38 basidiocarps grown on the territory of Holosiivskyi National Nature Park, Lysa Hora Regional Landscape Park and Feofaniya forest parcel (Ukraine). Results showed similarity of genetic variability of S. commune in different local populations. The heterozygote deficiency of some loci that was discovered might have resulted from new forms of allozymes that have not become widespread or due to small population sizes. The degree of differentiation of genes between local studied populations was moderate due to the high flow of genes. The absence of spatial structuration of genotypes is established, and the Mantel test showed a lack of interconnection between the genetic component and the geographical coordinates of the samples. It has been suggested that wind direction and terrain are the factors that influence the genetic structure of local populations.


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