Concepts and Methods of Community Ecology Applied to Freshwater Fisheries Management

1987 ◽  
Vol 44 (S2) ◽  
pp. s448-s470 ◽  
Author(s):  
D. O. Evans ◽  
B. A. Henderson ◽  
N. J. Bax ◽  
T. R. Marshall ◽  
R. T. Oglesby ◽  
...  
Keyword(s):  
Community Ecology ◽  
Fisheries Management ◽  
Species Interactions ◽  
Resource Partitioning ◽  
Community Dynamics ◽  
Fish Communities ◽  
Hierarchical Organization ◽  
Anthropogenic Factors ◽  
Food Web Structure ◽  
Space And Time

In this paper we review selected theory, hypotheses, and methods of community ecology with reference to fisheries management. Community ecology is concerned with theoretical and empirical studies of the behavior of species assemblages over space and time. Ideas that have evolved from these types of studies concerning hierarchical organization, resource partitioning, food webs, structural integration, stability, complexity, and production and their relevance to fisheries management are discussed. One main conclusion confirmed by the ASPY Symposium is that the productivity of fish communities is determined by energy inputs, nutrients, edaphic factors, and habitat variables but that the distribution of the production by species is strongly influenced by interactions between species. A related conclusion is that species interactions are size dependent because of morphological, physiological, and behavioral constraints on predator–prey relationships, resulting in a hierarchical organization. Further, density-dependent interactions (predation, competition) within and between species influence growth rates, size distributions, and age-specific mortality and reproductive rates, and vice versa. Anthropogenic factors such as fishing, nutrient enrichment, introduction of exotic species, and chemical contaminants tend to act differentially at the level of species, but due to interdependencies between species their effects are propagated at the community level by disrupting its size- and niche-structured organization. Fish communities can be managed as relatively discrete functional units, but dependency on whole system dynamics ultimately necessitates an ecosystem perspective. Development of a more quantitative theory of fish community dynamics will require improved descriptions of species interactions (food web structure, ontogenetic histories, resource partitioning, and body size dependency), better characterization of complexity, stability, and successional change in fish communities, additional knowledge of energy transfer through aquatic ecosystems, and improved methods of estimating biomass distributions in fish communities. Comparative studies over space and time and experimental and adaptive management are appropriate ways for fishery scientists and managers to acquire this knowledge.

scholarly journals Trophic interactions are mediated by the availability of water in temperate grassland ecosystems

2016 ◽  
Author(s):  
William Harrower ◽  
Lauchlan H Fraser ◽  
Roy Turkington
Keyword(s):  
Plant Growth ◽  
Food Webs ◽  
Water Availability ◽  
Species Interactions ◽  
Community Dynamics ◽  
Trophic Position ◽  
Food Web Structure ◽  
Rainfall Gradient ◽  
South Central ◽  
Vertebrate Predators

The addition or removal of predators from food webs by humans can have profound effects on the interactions between species. However, predators and primary producers are inextricably linked by the flow of energy through ecosystems. In temperate grasslands energy flow through ecosystems is often limited by water availability to plants. So, if the number and strength of interactions between species in grasslands depends on the amount of water available to plants, and we remove predators along a gradient in water availability, then we should see change in species interactions with predator removals along the gradient. After estimating trophic position and diet breadth of key predators, we excluded birds and small mammal predators from grasslands along a rainfall gradient in south central British Columbia for four years, and measured the response of plants and arthropods. Water availability significantly altered food web structure, and consequently the role of predators in structuring these ecosystems. When water was scarce, vertebrate predators impeded plant growth by feeding on spiders that would normally eat herbivorous insects. When water was more abundant, vertebrate predators facilitated plant growth by feeding on a broad range of arthropod prey. As water availability to plants increased they grew more. Herbivores were not able to consume all the new growth and thus dead plant material accumulated. Increasing detritus helped establish new links between predators and plants. Phenomena such as climate change can determine the availability of water entering ecosystems, which then alters trophic structure. If water availability can alter food webs there are no simple generalizations for community dynamics that are independent of climate.

scholarly journals A process-based metacommunity framework linking local and regional scale community ecology

2019 ◽  
Author(s):  
Patrick L. Thompson ◽  
Laura Melissa Guzman ◽  
Luc De Meester ◽  
Zsófia Horváth ◽  
Robert Ptacnik ◽  
...  
Keyword(s):  
Simulation Model ◽  
Community Ecology ◽  
Species Interactions ◽  
Community Dynamics ◽  
Regional Scale ◽  
Ecological Communities ◽  
Data Accessibility ◽  
Species Sorting ◽  
Wide Range ◽  
Underlying Processes

AbstractThe metacommunity concept has the potential to integrate local and regional dynamics within a general community ecology framework. To this end, the concept must move beyond the discrete archetypes that have largely defined it (e.g. neutral vs. species sorting) and better incorporate local scale species interactions and coexistence mechanisms. Here, we present a fundamental reconception of the framework that explicitly links local coexistence theory to the spatial processes inherent to metacommunity theory, allowing for a continuous range of competitive community dynamics. These dynamics emerge from the three underlying processes that shape ecological communities: 1) density-independent responses to abiotic conditions, 2) density-dependent biotic interactions, and 3) dispersal. Stochasticity is incorporated in the demographic realization of each of these processes. We formalize this framework using a simulation model that explores a wide range of competitive metacommunity dynamics by varying the strength of the underlying processes. Using this model and framework, we show how existing theories, including the traditional metacommunity archetypes, are linked by this common set of processes. We then use the model to generate new hypotheses about how the three processes combine to interactively shape diversity, functioning, and stability within metacommunities.Statement of authorshipThis project was conceived at the sTURN working group, of which all authors are members. PLT developed the framework and model with input from all authors. PLT wrote the model code. PLT and LMG performed the simulations. PLT produced the figures and wrote the first draft with input from LMG and JMC. All authors provided feedback and edits on several versions of the manuscript.Data accessibilityAll code for running the simulation model and producing the figures is archived on Zenodo - https://doi.org/10.5281/zenodo.3833035.

scholarly journals Trophic interactions are mediated by the availability of water in temperate grassland ecosystems

2016 ◽  
Author(s):  
William Harrower ◽  
Lauchlan H Fraser ◽  
Roy Turkington
Keyword(s):  
Plant Growth ◽  
Food Webs ◽  
Water Availability ◽  
Species Interactions ◽  
Community Dynamics ◽  
Trophic Position ◽  
Food Web Structure ◽  
Rainfall Gradient ◽  
South Central ◽  
Vertebrate Predators

The addition or removal of predators from food webs by humans can have profound effects on the interactions between species. However, predators and primary producers are inextricably linked by the flow of energy through ecosystems. In temperate grasslands energy flow through ecosystems is often limited by water availability to plants. So, if the number and strength of interactions between species in grasslands depends on the amount of water available to plants, and we remove predators along a gradient in water availability, then we should see change in species interactions with predator removals along the gradient. After estimating trophic position and diet breadth of key predators, we excluded birds and small mammal predators from grasslands along a rainfall gradient in south central British Columbia for four years, and measured the response of plants and arthropods. Water availability significantly altered food web structure, and consequently the role of predators in structuring these ecosystems. When water was scarce, vertebrate predators impeded plant growth by feeding on spiders that would normally eat herbivorous insects. When water was more abundant, vertebrate predators facilitated plant growth by feeding on a broad range of arthropod prey. As water availability to plants increased they grew more. Herbivores were not able to consume all the new growth and thus dead plant material accumulated. Increasing detritus helped establish new links between predators and plants. Phenomena such as climate change can determine the availability of water entering ecosystems, which then alters trophic structure. If water availability can alter food webs there are no simple generalizations for community dynamics that are independent of climate.

scholarly journals The Patterns and Puzzles of Genetic Diversity of Endangered Freshwater Mussel Unio crassus Philipsson, 1788 Populations from Vistula and Neman Drainages (Eastern Central Europe)

Life ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 119
Author(s):  
Adrianna Kilikowska ◽  
Monika Mioduchowska ◽  
Anna Wysocka ◽  
Agnieszka Kaczmarczyk-Ziemba ◽  
Joanna Rychlińska ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Spatial Scales ◽  
Freshwater Mussel ◽  
Its Region ◽  
Strong Relationship ◽  
Mantel Test ◽  
Freshwater Ecosystems ◽  
Hierarchical Organization ◽  
Anthropogenic Factors

Mussels of the family Unionidae are important components of freshwater ecosystems. Alarmingly, the International Union for Conservation of Nature and Natural Resources Red List of Threatened Species identifies almost 200 unionid species as extinct, endangered, or threatened. Their decline is the result of human impact on freshwater habitats, and the decrease of host fish populations. The Thick Shelled River Mussel Unio crassus Philipsson, 1788 is one of the examples that has been reported to show a dramatic decline of populations. Hierarchical organization of riverine systems is supposed to reflect the genetic structure of populations inhabiting them. The main goal of this study was an assessment of the U. crassus genetic diversity in river ecosystems using hierarchical analysis. Different molecular markers, the nuclear ribosomal internal transcribed spacer ITS region, and mitochondrial DNA genes (cox1 and ndh1), were used to examine the distribution of U. crassus among-population genetic variation at multiple spatial scales (within rivers, among rivers within drainages, and between drainages of the Neman and Vistula rivers). We found high genetic structure between both drainages suggesting that in the case of the analyzed U. crassus populations we were dealing with at least two different genetic units. Only about 4% of the mtDNA variation was due to differences among populations within drainages. However, comparison of population differentiation within drainages for mtDNA also showed some genetic structure among populations within the Vistula drainage. Only one haplotype was shared among all Polish populations whereas the remainder were unique for each population despite the hydrological connection. Interestingly, some haplotypes were present in both drainages. In the case of U. crassus populations under study, the Mantel test revealed a relatively strong relationship between genetic and geographical distances. However, in detail, the pattern of genetic diversity seems to be much more complicated. Therefore, we suggest that the observed pattern of U. crassus genetic diversity distribution is shaped by both historical and current factors i.e. different routes of post glacial colonization and history of drainage systems, historical gene flow, and more recent habitat fragmentation due to anthropogenic factors.

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

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.

The ecology of parasites of freshwater fishes: the search for patterns

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1653-1662 ◽  
Author(s):  
C. R. KENNEDY
Keyword(s):  
Community Dynamics ◽  
Parasite Community ◽  
Freshwater Fishes ◽  
Convincing Evidence ◽  
Helminth Parasites ◽  
Parasite Communities ◽  
Space And Time ◽  
Long Time ◽  
Population And Community Dynamics ◽  
Parasite Populations

SUMMARYDevelopments in the study of the ecology of helminth parasites of freshwater fishes over the last half century are reviewed. Most research has of necessity been field based and has involved the search for patterns in population and community dynamics that are repeatable in space and time. Mathematical models predict that under certain conditions host and parasite populations can attain equilibrial levels through operation of regulatory factors. Such factors have been identified in several host-parasite systems and some parasite populations have been shown to persist over long time-periods. However, there is no convincing evidence that fish parasite populations are stable and regulated since in all cases alternative explanations are equally acceptable and it appears that they are non-equilibrial systems. It has proved particularly difficult to detect replicable patterns in parasite communities. Inter-specific competition, evidenced by functional and numerical responses, has been detected in several communities but its occurrence is erratic and its significance unclear. Some studies have failed to find any nested patterns in parasite community structure and richness, whereas others have identified such patterns although they are seldom constant over space and time. Departures from randomness appear to be the exception and then only temporary. It appears that parasite communities are non-equilibrial, stochastic assemblages rather than structured and organized.

scholarly journals Introduction: Special issue on species interactions, ecological networks and community dynamics – Untangling the entangled bank using molecular techniques

2019 ◽  
Vol 28 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Tomas Roslin ◽  
Michael Traugott ◽  
Mattias Jonsson ◽  
Graham N. Stone ◽  
Simon Creer ◽  
...  
Keyword(s):  
Species Interactions ◽  
Community Dynamics ◽  
Ecological Networks ◽  
Molecular Techniques ◽  
Special Issue

Answers.

2020 ◽  
pp. 179-214
Author(s):  
Paul A. Rees
Keyword(s):  
Community Ecology ◽  
Population Ecology ◽  
Species Interactions ◽  
Abiotic Factors ◽  
Multiple Choice ◽  
Ecological Genetics ◽  
Major Topic ◽  
Production Ecology ◽  
Material Cycles ◽  
Ecological Methods

Abstract A multiple choice question has a stem (the 'question'), a key (the 'answer') and a number of distracters (wrong answers intended to distract the student from the key). This part of the book contains the key to each question along with a brief explanation of why this is correct and, in some cases, what the distracters mean. The questions are grouped into 10 major topic areas: (1) The history and foundations of ecology, (2) Abiotic factors and environmental monitoring, (3) Taxonomy and biodiversity, (4) Energy flow and production ecology, (5) Nutrient and material cycles, (6) Ecophysiology, (7) Population ecology, (8) Community ecology and species interactions, (9) Ecological genetics and evolution, (10) Ecological methods and statistics.

scholarly journals Biotic rescaling reveals importance of species interactions for variation in biodiversity responses to climate change

2020 ◽  
Vol 117 (37) ◽  
pp. 22858-22865 ◽  
Author(s):  
Vigdis Vandvik ◽  
Olav Skarpaas ◽  
Kari Klanderud ◽  
Richard J. Telford ◽  
Aud H. Halbritter ◽  
...  
Keyword(s):  
Climate Change ◽  
Species Interactions ◽  
Community Dynamics ◽  
Biotic Interactions ◽  
Plant Interactions ◽  
Climate Gradients ◽  
Climate Change Responses ◽  
Local Extinctions ◽  
Future Work ◽  
Underlying Processes

Generality in understanding biodiversity responses to climate change has been hampered by substantial variation in the rates and even directions of response to a given change in climate. We propose that such context dependencies can be clarified by rescaling climate gradients in terms of the underlying biological processes, with biotic interactions as a particularly important process. We tested this rescaling approach in a replicated field experiment where entire montane grassland communities were transplanted in the direction of expected temperature and/or precipitation change. In line with earlier work, we found considerable variation across sites in community dynamics in response to climate change. However, these complex context dependencies could be substantially reduced or eliminated by rescaling climate drivers in terms of proxies of plant−plant interactions. Specifically, bryophytes limited colonization by new species into local communities, whereas the cover of those colonists, along with bryophytes, were the primary drivers of local extinctions. These specific interactions are relatively understudied, suggesting important directions for future work in similar systems. More generally, the success of our approach in explaining and simplifying landscape-level variation in climate change responses suggests that developing and testing proxies for relevant underlying processes could be a fruitful direction for building more general models of biodiversity response to climate change.

scholarly journals Predicting N-Strain Coexistence from Co-colonization Interactions: Epidemiology Meets Ecology and the Replicator Equation

2020 ◽  
Vol 82 (11) ◽  
Author(s):  
Sten Madec ◽  
Erida Gjini
Keyword(s):  
Species Interactions ◽  
Community Dynamics ◽  
Secondary Infection ◽  
Social Systems ◽  
System Size ◽  
Replicator Equation ◽  
Efficient Computation ◽  
Volterra Systems ◽  
Infection Processes ◽  
Resistance To Invasion

AbstractMulti-type infection processes are ubiquitous in ecology, epidemiology and social systems, but remain hard to analyze and to understand on a fundamental level. Here, we study a multi-strain susceptible-infected-susceptible model with coinfection. A host already colonized by one strain can become more or less vulnerable to co-colonization by a second strain, as a result of facilitating or competitive interactions between the two. Fitness differences between N strains are mediated through $$N^2$$ N 2 altered susceptibilities to secondary infection that depend on colonizer-cocolonizer identities ($$K_{ij}$$ K ij ). By assuming strain similarity in such pairwise traits, we derive a model reduction for the endemic system using separation of timescales. This ‘quasi-neutrality’ in trait space sets a fast timescale where all strains interact neutrally, and a slow timescale where selective dynamics unfold. We find that these slow dynamics are governed by the replicator equation for N strains. Our framework allows to build the community dynamics bottom-up from only pairwise invasion fitnesses between members. We highlight that mean fitness of the multi-strain network, changes with their individual dynamics, acts equally upon each type, and is a key indicator of system resistance to invasion. By uncovering the link between N-strain epidemiological coexistence and the replicator equation, we show that the ecology of co-colonization relates to Fisher’s fundamental theorem and to Lotka-Volterra systems. Besides efficient computation and complexity reduction for any system size, these results open new perspectives into high-dimensional community ecology, detection of species interactions, and evolution of biodiversity.

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