Upstream trophic structure modulates downstream community dynamics via resource subsidies

AbstractIn many natural systems, the physical structure of the landscape dictates the flow of resources. Despite mounting evidence that communities’ dynamics can be indirectly coupled by reciprocal among-ecosystem resource flows, our understanding of how directional resource flows might indirectly link biological communities is limited. We here propose that differences in community structure upstream should lead to different downstream dynamics, even in the absence of dispersal. We report an experimental test of the effect of upstream community structure on downstream community dynamics in a simplified but highly controlled setting, using protist microcosms. We implemented directional flows of resources, without dispersal, from a standard resource pool into upstream communities of contrasting interaction structure and then to further downstream communities of either one or two trophic levels. Our results demonstrate that different types of species interactions in upstream habitats may lead to different population sizes and levels of biomass in these upstream habitats. This, in turn, leads to varying levels of detritus transfer (dead biomass) to the downstream communities, thus influencing their population densities and trophic interactions in predictable ways. Our results suggest that the structure of species interactions in directionally structured ecosystems can be a key mediator of alterations to downstream habitats. Alterations to upstream habitats can thus cascade down to downstream communities, even without dispersal.

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The importance of species interactions in eco-evolutionary community dynamics under climate change

Nature Communications ◽

10.1038/s41467-021-24977-x ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Anna Åkesson ◽

Alva Curtsdotter ◽

Anna Eklöf ◽

Bo Ebenman ◽

Jon Norberg ◽

...

Keyword(s):

Climate Change ◽

Species Interactions ◽

Community Dynamics ◽

Evolutionary Dynamics ◽

Negative Impact ◽

Trophic Levels ◽

Temperature Dependent ◽

Modeling Framework ◽

Impact Of Climate Change ◽

The Impact

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which features more detailed species interactions, integrating evolution and dispersal. We include species interactions within and between trophic levels, and additionally, we incorporate the feature that species’ interspecific competition might change due to increasing temperatures and affect the impact of climate change on ecological communities. Our modeling framework captures previously reported ecological responses to climate change, and also reveals two key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, our trait-based perspective reveals a strong positive relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Temperature-dependent competition consistently results both in higher trait variation and more responsive communities to altered climatic conditions. Our study demonstrates the importance of species interactions in an eco-evolutionary setting, further expanding our knowledge of the interplay between ecological and evolutionary processes.

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Evolutionary Community Ecology

10.23943/princeton/9780691088778.001.0001 ◽

2017 ◽

Cited By ~ 3

Author(s):

Mark A. McPeek

Keyword(s):

Natural Selection ◽

Community Ecology ◽

Species Interactions ◽

Evolutionary Dynamics ◽

Spatial Scales ◽

Species Interaction ◽

Trophic Levels ◽

Unified Framework ◽

Quaternary Period ◽

Biological Communities

This book develops a unified framework for understanding the structure of ecological community and the dynamics of natural selection that shape the evolution of the species inhabiting them. All species engage in interactions with many other species, and these interactions regulate their abundance, define their trajectories of natural selection, and shape their movement decisions. This book synthesizes the ecological and evolutionary dynamics generated by species interactions that structure local biological communities and regional metacommunities. The book explores the ecological performance characteristics needed for invasibility and coexistence of species in complex networks of species interactions. This species interaction framework is then extended to examine the ecological dynamics of natural selection that drive coevolution of interacting species in these complex interaction networks. The models of natural selection resulting from species interactions are used to evaluate the ecological conditions that foster diversification at multiple trophic levels. Analyses show that diversification depends on the ecological context in which species interactions occur and the types of traits that define the mechanisms of those species interactions. Lastly, looking at the mechanisms of speciation that affect species richness and diversity at various spatial scales and the consequences of past climate change over the Quaternary period, the book considers how metacommunity structure is shaped at regional and biogeographic scales. Integrating evolutionary theory into the study of community ecology, the book provides a new framework for predicting how communities are organized and how they may change over time.

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Habitat and community structure modulate fish interactions in a neotropical clearwater river

Neotropical Ichthyology ◽

10.1590/1982-0224-2019-0127 ◽

2020 ◽

Vol 18 (1) ◽

Cited By ~ 2

Author(s):

Lucas T. Nunes ◽

Renato A. Morais ◽

Guilherme O. Longo ◽

José Sabino ◽

Sergio R. Floeter

Keyword(s):

Community Structure ◽

Species Interactions ◽

Species Abundance ◽

Habitat Characteristics ◽

Agonistic Interaction ◽

Tropical Rivers ◽

Biological Communities ◽

Habitat Variation ◽

Clearwater River ◽

Fish Interactions

ABSTRACT Species interactions can modulate the diversity and enhance the stability of biological communities in aquatic ecosystems. Despite previous efforts to describe fish interactions in tropical rivers, the role of habitat characteristics, community structure, and trophic traits over these interactions is still poorly understood. To investigate among-habitat variation in substratum feeding pressure and agonistic interactions between fishes, we used remote underwater videos in three habitats of a clearwater river in the Central Western, Brazil. We also performed visual surveys to estimate the abundance and biomass of fishes and proposed a trophic classification to understand how these variables can affect fish interactions. Community structure was the main factor affecting the variation in the interactions among the habitats. Biomass was the main variable determining which habitat a fish will feed on, while species abundance determined with how many other species it will interact in the agonistic interaction networks for each habitat. Specific habitats are not only occupied, but also used in distinct ways by the fish community. Overall, our results demonstrate the importance of the heterogeneity of habitats in tropical rivers for the interactions performed by the fishes and how the intensity of these interactions is affected by community structure.

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Differentiating in the Community

Evolutionary Community Ecology ◽

10.23943/princeton/9780691088778.003.0005 ◽

2017 ◽

Author(s):

Mark A. McPeek

Keyword(s):

Climate Change ◽

Intraguild Predation ◽

General Model ◽

Species Interactions ◽

Evolutionary Dynamics ◽

Trophic Levels ◽

Ecological Differentiation ◽

Neutral Species ◽

Biological Communities ◽

Coexisting Species

This chapter explores the evolutionary dynamics that arise when different types of species mix together in a community either by invasion or by perturbation, as well as community mixing caused by climate change. In particular, it considers the features that promote or retard ecological differentiation of species. The chapter first describes a general model of evolutionary and ecological dynamics in a community before discussing adaptive differentiation at multiple trophic levels. It then examines differentiation of species with identical underlying parameters vs. different underlying parameters, along with intraguild predation and how ecological opportunity evolves within biological communities. It also investigates when neutral species will initially differentiate from one another to convert them into a set of coexisting species, and when differentiated species will initially converge to become ecologically more similar. The chapter shows that, when differentiation occurs, the type of traits underlying species interactions determine the ecological structure of the resulting community.

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The importance of species interactions in spatially explicit eco-evolutionary community dynamics under climate change

10.1101/2020.03.23.003335 ◽

2020 ◽

Author(s):

Anna Åkesson ◽

Alva Curtsdotter ◽

Anna Eklöf ◽

Bo Ebenman ◽

Jon Norberg ◽

...

Keyword(s):

Climate Change ◽

Species Interactions ◽

Community Dynamics ◽

Evolutionary Dynamics ◽

Negative Relationship ◽

Trophic Levels ◽

Spatially Explicit ◽

Modeling Framework ◽

Impact Of Climate Change ◽

The Impact

AbstractEco-evolutionary dynamics are essential in shaping the biological response of communities to ongoing climate change. Here we develop a spatially explicit eco-evolutionary framework which integrates evolution, dispersal, and species interactions within and between trophic levels. This allows us to analyze how these processes interact to shape species- and community-level dynamics under climate change. Additionally, we incorporate the heretofore unexplored feature that species interactions themselves might change due to increasing temperatures and affect the impact of climate change on ecological communities. The new modeling framework captures previously reported ecological responses to climate change, and also reveals two new key results. First, interactions between trophic levels as well as temperature-dependent competition within a trophic level mitigate the negative impact of climate change on global biodiversity, emphasizing the importance of understanding biotic interactions in shaping climate change impact. Second, using a trait-based perspective, we found a strong negative relationship between the within-community variation in preferred temperatures and the capacity to respond to climate change. Communities resulting from different ecological interaction structures form distinct clusters along this relationship, but varying species’ abilities to disperse and adapt to new temperatures leave it unaffected.

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Community Dynamics and Stability

Ecology of Climate Change ◽

10.23943/princeton/9780691148472.003.0006 ◽

2013 ◽

Author(s):

Eric Post

Keyword(s):

Community Composition ◽

Species Interactions ◽

Community Dynamics ◽

Species Coexistence ◽

Environmental Variability ◽

Climatic Variability ◽

Self Regulation ◽

Community Stability ◽

Biological Communities ◽

The Stability

This chapter explores the implications of climate change for community composition, dynamics, and stability. It also looks at further examples in which climatic variability mediates interactions among species, in some cases degrading community stability and in other cases promoting it. Ecological theory offers contrasting predictions regarding the consequences for species coexistence and community stability of environmental variability. For instance, short-term instabilities in community composition owing to, for example, high-frequency environmental disturbance may promote the long-term coexistence of species by preventing competitive exclusion of one species by another. Other work suggests, however, that the stability of biological communities in stochastic environments is only possible if there is sufficiently strong self-regulation at one or more trophic levels, or if self-regulation is strong while species interactions are weak, because environmental erosion of population stability at one trophic level may contribute to instability of the community as a whole.

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Bacterial presence in polar regions associated with environment modification by chemical compounds including contaminants

Environmental Reviews ◽

10.1139/er-2017-0007 ◽

2017 ◽

Vol 25 (4) ◽

pp. 481-491 ◽

Cited By ~ 4

Author(s):

Klaudia Kosek ◽

Katarzyna Jankowska ◽

Żaneta Polkowska

Keyword(s):

Bacterial Communities ◽

Chemical Compounds ◽

Freshwater Ecosystems ◽

Trophic Levels ◽

Polar Regions ◽

Bacterial Cells ◽

Chemical Contamination ◽

Climate Conditions ◽

Biological Communities ◽

Long Time

Microbes are omnipresent and diverse members of all biological communities. In marine and freshwater ecosystems, microorganisms form the base of the food chain supporting higher trophic levels. Even though microbes are generally thought to live in warm regions of Earth, many of them develop in cold climates. Polar regions remain relatively protected from widespread anthropogenic disturbances, which is a consequence of thier remoteness and extreme climate conditions. For a long time these regions were considered to be free from chemical contamination until scientists discovered a presence of pollutants there. Chemical contamination may induce serious disorders in the integrity of polar ecosystems influencing the growth of bacterial communities. Xenobiotics including persistent organic pollutants are transported thousands of kilometers by the air and ocean currents, and they are deposed in high-latitude regions and accumulate in all elements of the environment including bacterial communities. It is important to determine their concentration levels in bacterial cells to assess the possibility of contaminants becoming transferred to higher trophic levels; however, some species of bacteria are capable of metabolizing xenobiotics, which makes them less toxic or even removes them from the environment.

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