Food web structure of a subtropical headwater stream

2007 ◽  
Vol 58 (7) ◽  
pp. 596 ◽  
Author(s):  
I-Yu Huang ◽  
Yao-Sung Lin ◽  
Chang-Po Chen ◽  
Hwey-Lian Hsieh
Keyword(s):  
Food Web ◽  
Carbon Sources ◽  
Benthic Algae ◽  
Foraging Strategy ◽  
Headwater Stream ◽  
Feeding Guilds ◽  
Food Web Structure ◽  
Feeding Mode ◽  
Δ13c And Δ15n ◽  
Web Structure

The food web structure of a headwater stream (Hapen Creek) in subtropical northern Taiwan, which is subject to regular typhoon disturbances, was characterised using stable isotope techniques. δ13C and δ15N signatures were used to examine (i) the relative contributions of allochthonous versus. autochthonous sources to the web, and (ii) the trophic organisation of the community including the predominant feeding guilds and the most prevalent feeding mode. This study presents food web attributes for one of the very few food webs studied to date in a subtropical region. Consumers utilised allochthonous and autochthonous carbon sources differently depending on their trophic positions. The majority of consumers exploited more autochthonous carbon sources. Consumers at higher trophic positions in the food web had more direct and greater association with benthic algae. Higher-order consumers also consumed allochthonous carbon in an indirect manner by assimilating lower-order insects. The results reveal the importance of invertebrate consumer snails and aquatic insects in the transfer of organic matter. Omnivores predominated in the food web; this may reflect an opportunistic foraging strategy that enables them to adapt to hydrological disturbances and a fluctuating food supply.

scholarly journals Preliminary examination of food web structure of Nicola Lake (Taim Hydrological System, south Brazil) using dual C and N stable isotope analyses

2006 ◽  
Vol 4 (2) ◽  
pp. 279-284 ◽  
Author(s):  
Alexandre M. Garcia ◽  
David J. Hoeinghaus ◽  
João P. Vieira ◽  
Kirk O. Winemiller ◽  
David M. L. Motta Marques ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Food Web ◽  
Biological Diversity ◽  
Isotope Analysis ◽  
Carbon Sources ◽  
Stable Isotope Ratio ◽  
Trophic Levels ◽  
Food Web Structure ◽  
Web Structure ◽  
Hydrological System

Taim Ecological Reserve is located within the Taim Hydrological System and was created to protect a heterogeneous and productive landscape harboring exceptional biological diversity in southern Brazil. Using stable isotope ratio analyses of carbon (delta13C) and nitrogen (delta15N), we provide a preliminary description of the food web structure, including estimates of production sources supporting fish populations and vertical trophic structure, within a representative lake of this system. A total of 21 organisms (5 macrophytes, 3 mollusks and 13 adult fishes) representing 16 species were collected for isotope analysis. Fishes had delta13C values ranging from -24.30º/oo to -28.31º/oo , showing concordance with the range of values observed for macrophytes (-25.49 to -27.10º/oo), and suggesting that these plants could be a major carbon source supporting these fishes. delta13C signatures of Corbicula (-30.81º/oo) and Pomacea (-24.26º/oo) indirectly suggest that phytoplankton and benthic algae could be alternative carbon sources for some consumers. Nitrogen isotope ratios indicated approximately three consumer trophic levels. The pearl cichlid Geophagus brasiliensis was a primary consumer. Two catfishes (Trachelyopterus lucenai and Loricariichthys anus) were secondary consumers. Two congeneric pike cichclids (Crenicichla lepidota and C. punctata), a catfish (Pimelodus maculatus) and the characids Astyanax fasciatus and Oligosarcus robustus were tertiary consumers. Further studies including additional primary producers and consumers and greater sample numbers should be conducted to provide a more complete and detailed description of food web structure and dynamics within the reserve.

scholarly journals Relevance of evolutionary history for food web structure

2011 ◽  
Vol 279 (1733) ◽  
pp. 1588-1596 ◽  
Author(s):  
Anna Eklöf ◽  
Matthew R. Helmus ◽  
M. Moore ◽  
Stefano Allesina
Keyword(s):  
Food Web ◽  
Species Interactions ◽  
Evolutionary History ◽  
Species Traits ◽  
Interaction Networks ◽  
Food Web Structure ◽  
Feeding Mode ◽  
Closely Related Species ◽  
Marginal Likelihoods ◽  
Web Structure

Explaining the structure of ecosystems is one of the great challenges of ecology. Simple models for food web structure aim at disentangling the complexity of ecological interaction networks and detect the main forces that are responsible for their shape. Trophic interactions are influenced by species traits, which in turn are largely determined by evolutionary history. Closely related species are more likely to share similar traits, such as body size, feeding mode and habitat preference than distant ones. Here, we present a theoretical framework for analysing whether evolutionary history—represented by taxonomic classification—provides valuable information on food web structure. In doing so, we measure which taxonomic ranks better explain species interactions. Our analysis is based on partitioning of the species into taxonomic units. For each partition, we compute the likelihood that a probabilistic model for food web structure reproduces the data using this information. We find that taxonomic partitions produce significantly higher likelihoods than expected at random. Marginal likelihoods (Bayes factors) are used to perform model selection among taxonomic ranks. We show that food webs are best explained by the coarser taxonomic ranks (kingdom to class). Our methods provide a way to explicitly include evolutionary history in models for food web structure.

Benthic food web structure in the southeastern Chukchi Sea: an assessment using δ13C and δ15N analyses

Polar Biology ◽  
2010 ◽  
Vol 34 (4) ◽  
pp. 521-532 ◽  
Author(s):  
Howard M. Feder ◽  
Katrin Iken ◽  
Arny L. Blanchard ◽  
Stephen C. Jewett ◽  
Susan Schonberg
Keyword(s):  
Food Web ◽  
Chukchi Sea ◽  
Food Web Structure ◽  
Δ13c And Δ15n ◽  
Benthic Food Web ◽  
Web Structure ◽  
Benthic Food

Food-web structure in a subtropical coastal lake: how phylogenetic constraints may affect species linkages

2014 ◽  
Vol 65 (5) ◽  
pp. 453 ◽  
Author(s):  
Lúcia Ribeiro Rodrigues ◽  
Nelson Ferreira Fontoura ◽  
David da Motta Marques
Keyword(s):  
Food Web ◽  
Fish Species ◽  
Relative Size ◽  
Stomach Contents ◽  
Nitrogen Isotope ◽  
Trophic Levels ◽  
Coastal Lake ◽  
Food Web Structure ◽  
Δ13c And Δ15n ◽  
Web Structure

To describe a food-web structure is a main goal in any attempt to understand ecosystem functioning. In the present study, we analysed the isotopic composition (δ13C and δ15N) of primary producers and consumers in the large subtropical Mangueira Lake in southern Brazil. On the basis of the δ13C and δ15N values and analysis of stomach contents of several fish species, we provide a description of the food-web structure and trophic positions of the dominant fish species. Analysis of nitrogen isotope ratios indicated the existence of two consumer trophic levels. Isotopic signatures of primary consumers were compatible with those of producers, indicating a food web sustained by autochthonous carbon. Nevertheless, when food items were classified in larger groups by relative size and source, the combined analysis of isotopic signature and feeding preferences revealed a phylogenetically structured arrangement for the fish species of Mangueira Lake. This indicates that the main feeding niches are shared by taxonomically related species.

Invasive rodents have multiple indirect effects on seabird island invertebrate food web structure

2017 ◽  
Vol 27 (4) ◽  
pp. 1190-1198 ◽  
Author(s):  
Joshua J. Thoresen ◽  
David Towns ◽  
Sebastian Leuzinger ◽  
Mel Durrett ◽  
Christa P. H. Mulder ◽  
...  
Keyword(s):  
Food Web ◽  
Indirect Effects ◽  
Food Web Structure ◽  
Web Structure ◽  
Invasive Rodents
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