Environmental Control of Food Web Structure

Briand, Frédéric

doi:10.2307/1937073

Cited by 210 publications

(189 citation statements)

References 18 publications

Supporting

Mentioning

178

Contrasting

Order By: Relevance

“…In general, it appears that food webs in variable environments have fewer linkages than webs in more constant environments (Briand, 1983). However, it has also been shown experimentally that food chains are longer in more productive environments (Pimm and Kitching, 1987;Jenkins et al, 1992), and that population dynamics are less stable in long food chains than in short ones (Lawler and Morin, 1993).…”

Section: Comparative Analysesmentioning

confidence: 99%

Food webs in the ocean: who eats whom and how much?

Trites

2003

Responsible Fisheries in the Marine Ecosystem

View full text Add to dashboard Cite

Over 100 food webs have been published for marine ecosystems to describe the transfer of food energy from its source in plants, through herbivores, to carnivores and higher order predators. The webs suggest that the lengths of the chains that form food webs are typically short (3-4 links), and that ecosystems with long food chains may be less stable than those with shorter food chains.Stomach contents have been the primary means for determining what marine organisms eat. More recently developed techniques include faecal analysis and fatty acid signatures from blood or fat samples. Consumption has been estimated from the volume of food found in stomachs, from the feeding rates of captive individuals and from bio-energetic modelling. Consumption of marine organisms, expressed as a percentage of an individual's body weight per day, ranges from about 4-15% for zooplankton, to 1-4% for cephalopods, 1-2% for fish, 3-5% for marine mammals and 15-20% for sea birds. Immature age classes consume about twice as much (per unit of body weight) as do mature individuals. Furthermore, consumption is not constant throughout the year, but varies with seasonal periods of growth and reproduction. Most groups of species consume 3-10 times more than they produce, and export or pass up the food web about 70-95% of their production. Marine organisms tend to be larger at successive trophic levels and are limited in the sizes of food they can consume. Humans are one of the few species that can prey upon almost any level of the food chain and any size of prey.Food web analysis and estimates of consumption are essential for understanding which ecosystems can support additional species, and which may be less stable and susceptible to species loss through the synergistic effects of fishing or culling. They are also critical tools for understanding changes in ecosystem dynamics as highlighted by a case study from the eastern Bering Sea.

show abstract

Section: Comparative Analysesmentioning

confidence: 99%

Food webs in the ocean: who eats whom and how much?

Trites

2003

Responsible Fisheries in the Marine Ecosystem

View full text Add to dashboard Cite

show abstract

“…If the top predator(s) of a web spent much time in a habitat or medium other than their prey, however, the investigator(s) did not generally include them (for example, birds and mammals for food web descriptions of the rocky intertidal, streams, and some terrestrial habitats). Of the 12 three-dimensional webs included in our analysis, the four with the lowest mean (1), (B) the subset of twodimensional webs from the first 40 webs (1), and (C) the subset of two-dimensional webs with web 12 corrected to reflect the mean chain length of the food web presented by Briand (5) chain lengths were all terrestrial (webs 24, 25, 27, and 40), three of which appear incomplete, followed by relatively complete aquatic habitats with longer chains. For the two-dimensional webs, seven out of eight webs are incomplete (terrestrial habitats, marshes, and the rocky intertidal).…”

Section: Habitat Compartmentation and Environmental Correlates Of Foomentioning

confidence: 99%

Habitat Compartmentation and Environmental Correlates of Food Chain Length

Moore¹,

Walter²,

Hunt³

1989

Science

View full text Add to dashboard Cite

Habitat Compartmentation and EnvironmentalCorrelates of Food Chain Length Briand and Cohen (1) condude that "the primary decomposers (bacteria and saprodimensionality of the environment influ-phytic fungi) or do not have phytoplankton ences mean or maximal [food] chain length distinguished from zooplankton. more than environmental variability" but doWe find that the concept of habitat dinot offer an explanation. After examining mensionality lacks sufficient rigor to be used the first 40 food webs that Briand and in a standardized manner. In the study by Cohen present (1), we find that most of the Briand and Cohen, three-dimensional (soldifference in chain length between habitats id) habitats include lakes, oceans, and forests of different dimensions appears to be an (including kelp beds), whereas two dimenartifact of the completeness of the web sional (flat) habitats include creeks, rivers, descriptions. Our calculations indicate that intertidal zones, marshes, grasslands, deserts the first 40 webs are an adequate sample, as and tundra. Habitats with both two-and the range and median chain lengths of webs three-dimensional aspects are considered to 1 through 40 are similar to those of webs 1 have mixed dimensions. Habitats may apthrough 113 (Fig. 1).pear to us as solid or flat; however, we Many of the webs presented by Briand question whether organisms within the haband Cohen are truncated. In the first 40 itats make this distinction. For example, the webs, 17% of the 138 "producers" are actu-Long Island salt-marsh (estuary) includes an ally consumers. For example, the Aspen air column for birds, a water column large parkland community food web (2) produc-enough to support pelagic organisms and ers include primary producers, but also con-plankton, and a flat bottom for molluscs and sumers, for example, coots, ducks, mice, and water plants; yet We do not mean to criticize the original missing. In the New Zealand salt-meadow food web studies, since their objectives did (3) the low mean chain length (1.96) results not include having the webs subjected to from single-link chains that portray orga-structural analyses; however, the completenisms such as weevil larvae, Hemiptera, ness of Briand and Cohen's descriptions of harpacticoids, staphylinids, dipterous larvae, the food webs is confounded with the webs' haplotaxid worms, oribatid mites, bumble-dimensions. In the three-dimensional habibees, adult Hymenoptera, and redpolls as tats of Briand and Cohen, phytoplankton top predators. Jones (4) described a web for are differentiated from zooplankton and the River Clydach that included predatory generally include top predators [see webs fish, but Briand and Cohen and others (5, 6) 17, 19-21, 24, 25, 27, 29-32, and 40 (1, use a simplified web for this system, in 5)], whereas the two-dimensional habitats which predatory fish and some intermediate [webs 3, 10-13, 23, 34, and 35 (1, 5)] do consumers are deleted. Numerous webs are not have plankton differentiated and lack missing predatory birds and insects and top pred...

show abstract

“…Connectance usually represents the degree of generalization or redundancy in a system, with consequences for community stability (May 1973;Jordano 1987). Connectance has been frequently reported to decrease with the total number of species participating in mutualistic plantanimal interactions (Jordano 1987;Olesen & Jordano 2002;Blü thgen et al 2007;Aizen et al 2008) and food webs (Briand 1983;Schoenly et al 1991;cf. Winemiller 1989;Warren 1990).…”

Section: Introductionmentioning

confidence: 99%

Species interactions–area relationships: biological invasions and network structure in relation to island area

Sugiura

2010

Proc. R. Soc. B.

View full text Add to dashboard Cite

The relationship between species number and island area is a fundamental rule in ecology. However, the extent to which interactions with exotic species and how the structure of species interactions is related to island area remain unexplored. Here, I document the relationship between island area and (i) interactions with exotic species and (ii) network structure of species interactions in the context of mutualistic interactions between ants and extrafloral nectary-bearing plants on the oceanic Ogasawara (Bonin) Islands, Japan. Pooled data contained 122 interactions among 19 plant (including five exotic) and 23 ant (including 20 exotic) species. Of the observed interactions, 82.8 per cent involved at least one exotic species, ranging from 68.2 to 86.4 per cent among islands. The number of links including exotic species increased in proportion to island area, although the number of links excluding exotic species did not. These results indicate that the number of interactions with exotic species increased in proportion to island area. Connectance, or the proportion of interactions actually observed among all possible interactions, decreased with island area. Nestedness, an asymmetry index in the species interaction network, also decreased with island area. Therefore, island area affects both the number of interactions with exotic species and the network structure.

show abstract

Environmental Control of Food Web Structure

Cited by 210 publications

References 18 publications

Food webs in the ocean: who eats whom and how much?

Food webs in the ocean: who eats whom and how much?

Habitat Compartmentation and Environmental Correlates of Food Chain Length

Species interactions–area relationships: biological invasions and network structure in relation to island area

Contact Info

Product

Resources

About