Variable niche breadth in benthic diatoms: Implications of ecological specialization and generalization for community structure

2020 ◽  
Vol 46 (5) ◽  
pp. 1131-1139 ◽  
Author(s):  
Andrew J. Bramburger ◽  
Paul B. Hamilton ◽  
G. Douglas Haffner ◽  
Peter E. Hehanussa
Keyword(s):  
Community Structure ◽  
Niche Breadth ◽  
Benthic Diatoms ◽  
Ecological Specialization

scholarly journals Shift in polar benthic community structure in a fast retreating glacial area of Marian Cove, West Antarctica

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hanna Bae ◽  
In-Young Ahn ◽  
Jinsoon Park ◽  
Sung Joon Song ◽  
Junsung Noh ◽  
...  
Keyword(s):  
Community Structure ◽  
Benthic Community ◽  
Adaptive Strategy ◽  
Ecological Impacts ◽  
Glacier Retreat ◽  
Benthic Diatoms ◽  
Subtidal Zone ◽  
Benthic Community Structure ◽  
Community Shift ◽  
Global Issue

AbstractGlacier retreat is a major long-standing global issue; however, the ecological impacts of such retreats on marine organisms remain unanswered. Here, we examined changes to the polar benthic community structure of “diatoms” under current global warming in a recently retreated glacial area of Marian Cove, Antarctica. The environments and spatiotemporal assemblages of benthic diatoms surveyed in 2018–2019 significantly varied between the intertidal (tidal height of 2.5 m) and subtidal zone (10 and 30 m). A distinct floral distribution along the cove (~ 4.5 km) was characterized by the adaptive strategy of species present, with chain-forming species predominating near the glacier. The predominant chain-forming diatoms, such as Fragilaria striatula and Paralia sp., are widely distributed in the innermost cove over years, indicating sensitive responses of benthic species to the fast-evolving polar environment. The site-specific and substrate-dependent distributions of certain indicator species (e.g., F. striatula, Navicula glaciei, Cocconeis cf. pinnata) generally reflected such shifts in the benthic community. Our review revealed that the inner glacier region reflected trophic association, featured with higher diversity, abundance, and biomass of benthic diatoms and macrofauna. Overall, the polar benthic community shift observed along the cove generally represented changing environmental conditions, (in)directly linked to ice-melting due to the recent glacier retreat.

scholarly journals Community structure and niche breadth of some fish in Pangelang Protected Lake, Kapuas Hulu District

2021 ◽  
Vol 21 (2) ◽  
pp. 105-115
Author(s):  
Sri Endah Purnamaningtyas ◽  
Dimas Angga Hedianto ◽  
Nurfiarini Nurfiarini
Keyword(s):  
Community Structure ◽  
Fish Community ◽  
Niche Breadth ◽  
Fish Communities ◽  
Food Preferences ◽  
Survey Method ◽  
Fish Community Structure ◽  
Regional Patterns ◽  
Weather Changes ◽  
Detritivorous Fish

Ecologically, weather changes cause local deviations from regional patterns in waters. So that there will be changes in fish types and food habits.The purpose of this study was to determine changes in fish community structure, food preferences, and area of niches for each type of fish in Pangelang Protected Lake. The research was conducted using a survey method in October 2016 (low tide), June 2018 (transition) and September (flood) 2018. The results obtained: 1. Fish communities in Lake Pangelang obtained a total of 12 families, 30 genera, and 37 species. In the low tide season, there are 21 species of fish caught, 17 species of transition season and 16 types of flood during low tide. 2. In the low tide season, the fish community in Pangelang Lake is dominated by detritivorous fish. In the transitional season, the fish community in Pangelang Lake experiences changes with an increase in the union of phytoplanktivore and insectivore fish. During the flood season, the fish communities in Lake Pangelang underwent a change again where the union of herbivores that used plants increased.

Environmental and Spatial Influences on Biogeography and Community Structure of Saltmarsh Benthic Diatoms

2020 ◽  
Vol 44 (1) ◽  
pp. 147-161
Author(s):  
Craig J. Plante ◽  
Kristina Hill-Spanik ◽  
Maxwell Cook ◽  
Connor Graham
Keyword(s):  
Community Structure ◽  
Benthic Diatoms

scholarly journals Diet and niche breadth and overlap in fish communities within the area affected by an Amazonian reservoir (Amapá, Brazil)

2014 ◽  
Vol 86 (1) ◽  
pp. 383-406 ◽  
Author(s):  
JÚLIO C. SÁ-OLIVEIRA ◽  
RONALDO ANGELINI ◽  
VICTORIA J. ISAAC-NAHUM
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Fish Species ◽  
Niche Breadth ◽  
Null Model ◽  
Stomach Contents ◽  
Physical Conditions ◽  
River Damming ◽  
Standard Configuration ◽  
Feeding Resources

We investigated the niche breadth and overlap of the fish species occurring in four environments affected by the Coaracy Nunes reservoir, in the Amapá Brazilian State. Seasonal samples of fishes were taken using a standard configuration of gillnets, as well as dragnets, lines, and castnets. Five hundred and forty stomach contents, representing 47 fish species were analyzed and quantified. Niche breadth and overlap were estimated using indexes of Levins and Pianka, respectively, while interspecific competition was evaluated using a null model (RA3). ANOVA and the KruskalWallis test were used, respectively, to evaluate differences in niche breadth and overlap between areas. The data indicate that the majority of the fish species belong to the piscivore, omnivore, and detritivore guilds. These species have likely colonized the environments due to the availability of suitable feeding resources, and the favorable physical conditions created by the river damming. Overall, few species have ample niches, but most of them are highly specialized. Resources seasonal variation had little effect on the feeding behavior of most species in the study areas. The null models indicated that competition was not a factor determining on community structure.

scholarly journals Intraspecific Competition and the Promotion of Ecological Specialization

2021 ◽  
Author(s):  
Abdel H. Halloway ◽  
Joel S. Brown
Keyword(s):  
Resource Use ◽  
Intraspecific Competition ◽  
Niche Breadth ◽  
Evolutionary Model ◽  
Ecological Specialization ◽  
Secondary Resources ◽  
Cast Doubt ◽  
The Face ◽  
Game Theoretic ◽  
Diversification Hypothesis

AbstractThe evolution of ecological specialization can be summed up in a single question: why would a species evolve a more-restricted niche space? Various hypotheses have been developed to explain the promotion or suppression of ecological specialization. One hypothesis, competitive diversification, states that increased intraspecific competition will cause a population to broaden its niche breadth. With individuals alike in resource use preference, more individuals reduce the availability of preferred resources and should grant higher fitness to those that use secondary resources. However, recent studies cast doubt on this hypothesis with increased intraspecific competition reducing niche breadth in some systems. We present a game-theoretic evolutionary model showing greater ecological specialization with intraspecific competition under specific conditions. This is in contrast to the competitive diversification hypothesis. Our analysis reveals that specialization can offer a competitive advantage. Largely, when facing weak competition, more specialized individuals are able to acquire more of the preferred resources without greatly sacrificing secondary resources and therefore gain higher fitness. Only when competition is too great for an individual to significantly affect resource use will intraspecific competition lead to an increased niche breadth. Other conditions, such as a low diversity of resources and a low penalty to specialization, help promote ecological specialization in the face of intraspecific competition. Through this work, we have been able to discover a previously unseen role that intraspecific competition plays in the evolution of ecological specialization.

scholarly journals Asexual parasites and their extraordinary host ranges

2019 ◽  
Vol 59 (6) ◽  
pp. 1463-1484 ◽  
Author(s):  
Amanda K Gibson
Keyword(s):  
Host Range ◽  
Niche Breadth ◽  
Positive Association ◽  
Scale Insects ◽  
Evolution Of Sex ◽  
Ecological Specialization ◽  
Geographic Parthenogenesis ◽  
Link Theory ◽  
First Pass ◽  
Large Host

Abstract In diverse parasite taxa, from scale insects to root-knot nematodes, asexual lineages have exceptionally large host ranges, larger than those of their sexual relatives. Phylogenetic comparative studies of parasite taxa indicate that increases in host range and geographic range increase the probability of establishment of asexual lineages. At first pass, this convergence of traits appears counter-intuitive: intimate, antagonistic association with an enormous range of host taxa correlates with asexual reproduction, which should limit genetic variation within populations. Why would narrow host ranges favor sexual parasites and large host ranges favor asexual parasites? To take on this problem I link theory on ecological specialization to the two predominant hypotheses for the evolution of sex. I argue that both hypotheses predict a positive association between host range and the probability of invasion of asexual parasites, mediated either by variation in population size or in the strength of antagonistic coevolution. I also review hypotheses on colonization and the evolution of niche breadth in asexual lineages. I emphasize parasite taxa, with their diversity of reproductive modes and ecological strategies, as valuable assets in the hunt for solutions to the classic problems of the evolution of sex and geographic parthenogenesis.

scholarly journals Spatio-temporal trends in the predation of large gulls by peregrine falcons (Falco peregrinus) in an insular breeding population

2017 ◽  
Vol 11 (1) ◽  
pp. 103-109
Author(s):  
Luke J. Sutton ◽  
Ryan A. Burrell ◽  
Seb Loram
Keyword(s):  
Community Structure ◽  
Temporal Trends ◽  
Trophic Levels ◽  
Generalist Predators ◽  
Unexpected Result ◽  
Ecological Specialization ◽  
Falco Peregrinus ◽  
Diet Specialization ◽  
Herring Gulls ◽  
Peregrine Falcons

Abstract Individual diet specialization occurs in many populations of generalist predators, with specific individuals developing specialist strategies in their feeding behaviour. Intraspecific resource partitioning is hypothesised to be common amongst species in higher trophic levels where competition for resources is intense, and a key driver in breeding success and community structure. Though well-studied in other predators, there is sparse data on ecological specialization in raptors, which are important drivers of community and trophic structure. In this study, the breeding season diet of an insular population of peregrine falcons (Falco peregrinus) was determined from indirect analysis of prey remains collected over three years. An unexpected result was the high proportion of large gulls (Laridae), of the genus Larus, in the diet of two breeding pairs of peregrines. Large gulls made up 18.44% by frequency of total prey recorded and 30.81% by biomass. Herring gulls (Larus argentatus) were the most common large gull prey, with immatures most frequent (67.95%) compared to adults (19.23%). Overall, most gulls predated were immatures (80.77%). Frequency of predation varied between breeding pairs and months, but was consistent over the three years. Most gulls were taken in April (37.17%), followed by May (19.23%), with a smaller peak of immature herring gulls taken in August and September. The pattern of regular predation by peregrines on large gulls is a new observation with important implications for understanding individual diet specialization in raptors, and its effect on bird populations and community structure.

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