Moving among Communities

2017 ◽  
Author(s):  
Mark A. McPeek
Keyword(s):  
Community Structure ◽  
Local Adaptation ◽  
Local Community ◽  
Evolutionary Dynamics ◽  
Spatial And Temporal Variation ◽  
Evolution Of Dispersal ◽  
Movement Strategies ◽  
Regional Community ◽  
Dispersal Evolution ◽  
The Impact

This chapter examines the ecological and evolutionary dynamics of species across a metacommunity, and how these dynamics affect regional community structure. It begins with a discussion of the evolution of dispersal, focusing on when movement between local communities is and is not favored by natural selection, and how these various movement patterns shape local community structure. An example of the demographic consequences of dispersal is presented, and the evolution of dispersal in a temporally constant environment is analyzed. The chapter also considers the evolution of dispersal rates among communities along with local adaptation within each and explains how link species affect local abundances via their movement strategies. Finally, it explores the interplay between local adaptation and dispersal evolution, the impact of simultaneous spatial and temporal variation in environmental conditions on the evolution of dispersal among populations, and the evolution of phenotypic plasticity.

Ecological Opportunities, Communities, and Evolution

2017 ◽  
Author(s):  
Mark A. McPeek
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Ecology ◽  
Local Community ◽  
Evolutionary Dynamics ◽  
Evolutionary Adaptation ◽  
Regional Patterns ◽  
Interacting Species ◽  
Evolutionary Trajectories ◽  
Regional Community

This book investigates how local and regional patterns of community structure develop across space and through time by focusing on the theoretical interrelationships among community ecology, evolutionary adaptation, dispersal, and speciation and extinction. It discusses the purely ecological dynamics of interacting species in different community modules, how species in simple community modules evolve to adapt to one another, and how speciation and biogeographic mixing of taxa influence local community structure. It also examines community mixing due to climate change and how regional community structure is shaped by the ecological and evolutionary dynamics of species across a metacommunity. This introduction provides an overview of the evolutionary trajectories of various species in the context of ecological opportunity and community ecology, aggregated taxa in the trophic web, types of species found in a community, sources of biodiversity in a community, and the dynamics of natural selection, coevolution, and community structure.

scholarly journals Impact of fish cage-culture on the community structure of zooplankton in a tropical reservoir

2011 ◽  
Vol 101 (1-2) ◽  
pp. 75-84 ◽  
Author(s):  
Juliana D Dias ◽  
Érica M Takahashi ◽  
Natália F Santana ◽  
Cláudia C Bonecker
Keyword(s):  
Community Structure ◽  
Food Availability ◽  
Community Dynamics ◽  
Zooplankton Community ◽  
Fish Farming ◽  
Spatial And Temporal Variation ◽  
Cage Culture ◽  
Tropical Reservoir ◽  
Zooplankton Community Structure ◽  
The Impact

We investigated the impact of fish cage culture on the zooplankton community structure in a tropical reservoir. We hypothesized that community abundance is greater near cages and increases over time due to the increase in food availability. Samplings were performed near, upstream and downstream from net cages, and before and after net cage installation. The abundance of zooplankton increased 15 days after the experiment was set up, followed by a reduction and finally increased. Rotifer abundance showed significant differences among sites (p<0.05) and sampling periods (p<0.001). Significant differences were also observed in total zooplankton and cladoceran abundance (p<0.001). The spatial and temporal variation of the physical and chemical variables were indirectly correlated with the structure and dynamic of the zooplankton community, as they indicated the primary production in the environment. Our hypothesis was rejected, since the zooplankton was abundant at the reference site. Only rotifers showed higher abundance near cages, due to the influence of food availability. Community dynamics during the experiment was also correlated to food availability. Our results suggest an impact of fish farming on the zooplankton community.

scholarly journals Local adaptation, dispersal evolution, and the spatial eco‐evolutionary dynamics of invasion

2019 ◽  
Vol 22 (5) ◽  
pp. 767-777 ◽  
Author(s):  
Martín Andrade‐Restrepo ◽  
Nicolas Champagnat ◽  
Régis Ferrière
Keyword(s):  
Local Adaptation ◽  
Evolutionary Dynamics ◽  
Dispersal Evolution

New Species for the Community

2017 ◽  
Author(s):  
Mark A. McPeek
Keyword(s):  
Climate Change ◽  
Invasive Species ◽  
Community Structure ◽  
New Species ◽  
Local Community ◽  
Habitat Alteration ◽  
Phenotypic Differences ◽  
Extinction Rates ◽  
Regional Community ◽  
Past Climate Change

This chapter considers the main processes that operate at the regional and biogeographic scales to ultimately shape local community structure—namely, speciation and biogeographic mixing of taxa. It first defines what a “species” is before discussing the range of mechanisms that give rise to new species, and more specifically reproductive isolation. In particular, it examines the extent to which the speciation process directly induces differences in ecologically important traits between the progenitor and daughter species. It then explains how the phenotypic differences generated at the time of speciation determine what type of community member the new species begins as. It also shows how past climate change affected current local and regional community structure by periodic forcing of mass movements of species across Earth and causing increases in speciation and extinction rates. Finally, it evaluates the dynamics of invasive species and their role in habitat alteration today.

scholarly journals Influence of hydrological factors on bacterial community structure in a tropical monsoonal estuary in India

2021 ◽  
Author(s):  
Parvathi Ammini ◽  
Michela R Catena ◽  
Jasna Vijayan ◽  
Nikhil Phadke ◽  
Nikhita Gogate
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Bacterial Communities ◽  
Bacterial Community Structure ◽  
Salinity Gradient ◽  
Pearson Correlation ◽  
Temporal Variations ◽  
Spatial And Temporal Variation ◽  
Physico Chemical ◽  
The Impact

Abstract In the present study, we analysed variations in bacterial community structure along a salinity gradient in a tropical monsoonal estuary (Cochin estuary, CE), on the southwest coast of India, using Illumina next-generation sequencing (NGS). Water samples were collected from eight different locations thrice a year, to assess the variability in the bacterial community structure and to determine the physico-chemical factors influencing the bacterial diversity. Proteobacteria was the most dominant phyla in the estuary followed by Bacteroidetes, Cyanobacteria, Actinobacteria, and Firmicutes. Statistical analysis indicated significant variations in bacterial communities between freshwater, mesohaline and euryhaline regions, as well as between the monsoon (wet) and non-monsoon (dry) periods. Non-metric multidimensional scaling (NMDS) analysis demonstrated that the bacterial communities cluster according to different salinity regimes of the estuary. Canonical Correspondence analysis (CCA) showed a clear spatial and temporal variation in the distribution of bacterial communities in the CE. Abundance of Betaproteobacteria was high in the freshwater regions, while Gammaproteobacteria, Alphaproteobacteria and Epsilonproteobactera were more abundant in mesohaline and euryhaline regions of the estuary. Correlagram based on Pearson correlation analysis demonstrated the impact of different physico-chemical variables on the distribution of dominant phyla, class and genera. Spatial and temporal variations in bacterial community structure could be due to regional variations in environmental conditions imparted by allochthonous inputs, monsoonal rainfall, and tidal influence.

THE IMPACT OF DECENTRALIZATION ON THE DEVELOPMENT OF ENTREPRENEURSHIP IN UKRAINE

2017 ◽  
Author(s):  
Lyudmyla Mishchenko ◽  
◽  
Dmytro Mishchenko ◽  
Keyword(s):  
Social Entrepreneurship ◽  
Local Governments ◽  
Poverty Reduction ◽  
Social Protection ◽  
Local Community ◽  
Well Being ◽  
Economic Incentives ◽  
Social Enterprises ◽  
Infrastructural Support ◽  
The Impact

The actualization of the results of financial decentralization in Ukraine as part of the reform of decentralization of power and the development of proposals for its improvement is explained by the fact that a clear division of functions, powers and financial resources between national and regional levels is the basis for the well-being of our citizens. opportunities for its sustainable socio- economic development on a democratic basis. It is noted that financial decentralization is a process of giving authority to mobilize revenues and expenditures of local governments in order to increase the effectiveness of the implementation of these powers and better management of community budgets. It is established that unlike traditional entrepreneurship, which focuses on profit generation, the purpose of social entrepreneurship is to create and accumulate social capital. Abroad, social enterprises operate successfully in the fields of education, the environment, human rights, poverty reduction and health care, and their development and dissemination is one way to improve the living conditions of citizens. A similar mission is entrusted to local governments, which allows us to consider the revival of social entrepreneurship as an important element in improving self-government policy. It is determined that in modern conditions social entrepreneurship is one of the tools to ensure the ability of the local community to provide its members with an appropriate level of education, culture, health, housing and communal services, social protection, etc., as well as plan and implement programs efficient use of available natural and human resources, investment and infrastructural support of territorial communities. Due to financial decentralization, local governments have received additional resources that can be used to create economic incentives to promote social entrepreneurship in small and medium-sized businesses at the community level.

scholarly journals Response of ocean phytoplankton community structure to climate change over the 21st century: partitioning the effects of nutrients, temperature and light

2010 ◽  
Vol 7 (12) ◽  
pp. 3941-3959 ◽  
Author(s):  
I. Marinov ◽  
S. C. Doney ◽  
I. D. Lima
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Sea Ice ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Vertical Mixing ◽  
Phytoplankton Community Structure ◽  
Marginal Sea ◽  
Small Phytoplankton ◽  
The Impact

Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.

scholarly journals Spatial and Temporal Variation in Microbial Diversity and Community Structure in a Contaminated Mangrove Wetland

2020 ◽  
Vol 10 (17) ◽  
pp. 5850
Author(s):  
Jiaojiao Ma ◽  
Ting Zhou ◽  
Chunyu Xu ◽  
Dawen Shen ◽  
Songjun Xu ◽  
...  
Keyword(s):  
Community Structure ◽  
Spatial Variation ◽  
Temporal Variation ◽  
Bacterial Diversity ◽  
Diversity Index ◽  
Total Carbon ◽  
Spatial And Temporal Variation ◽  
Rrna Gene ◽  
Mangrove Wetland ◽  
Mangrove Soils

Field and laboratory investigations were conducted to characterize bacterial diversity and community structure in a badly contaminated mangrove wetland adjacent to the metropolitan area of a megacity in subtropical China. Next-generation sequencing technique was used for sequencing the V4–V5 region of the 16s rRNA gene on the Illumina system. Collectively, Proteobacteria, Chloroflexi, Planctomycetes, Actinobacteria and Bacteroidetes were the predominant phyla identified in the investigated soils. A significant spatial variation in bacterial diversity and community structure was observed for the investigated mangrove soils. Heavy metal pollution played a key role in reducing the bacterial diversity. The spatial variation in soil-borne heavy metals shaped the spatial variation in bacterial diversity and community structure in the study area. Other environmental factors such as total carbon and total nitrogen in the soils that are affected by seasonal change in temperature could also influence the bacterial abundance, diversity and community structure though the temporal variation was relatively weaker, as compared to spatial variation. The bacterial diversity index was lower in the investigated site than in the comparable reference site with less contaminated status. The community structure in mangrove soils at the current study site was, to a remarkable extent, different from those in the tropical mangrove wetlands around the world.

scholarly journals Multi-Criteria Analysis of the Mass Tourism Management Model Related to the Impact on the Local Community in Constanta City (Romania)

Inventions ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 46
Author(s):  
Catalin Anton ◽  
Angela-Eliza Micu ◽  
Eugen Rusu
Keyword(s):  
Black Sea ◽  
Seasonal Cycle ◽  
Local Community ◽  
Local Economy ◽  
Management Model ◽  
The Black Sea ◽  
Mass Tourism ◽  
Tourism Management ◽  
The Impact ◽  
The City

Traditionally and socially, the tourism in Constanta is considered to be important to the local economy. Sun and beach locations are both a draw for locals and tourists to the city, on the Black Sea. However, vacation-oriented activities in the city only have a seasonal cycle. In this paper, we proposed to analyze the mass tourist activity in Constanta, taking into account economic, social, and environmental conditions. Additionally, we attempted to build a model based on the data available. The model was developed using a PESTEL analysis to determine the supportability factor of the indicators identified. We also set out to create a projection of the activities proposed for analysis by 2050. To create a model for coastal areas, the data used in this research must be accurate and consistent. Furthermore, correctly identifying indicators and their relationships is a critical step in conducting a thorough study. Last but not least, finding the calculation coefficient for the activity in question is critical, as collecting data from various activities might be challenging when trying to find a feasible model.

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