| 1. |
- Brose, Ulrich, et al.
(författare)
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Consumer-resource body-size relationships in natural food webs
- 2006
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Ingår i: Ecology. - : Ecological Society of America esa. - 0012-9658 .- 1939-9170. ; 87:10, s. 2411-2417
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Tidskriftsartikel (refereegranskat)abstract
- It has been suggested that differences in body size between consumer and resource species may have important implications for interaction strengths, population dynamics, and eventually food web structure, function, and evolution. Still, the general distribution of consumer-'resource body-size ratios in real ecosystems, and whether they vary systematically among habitats or broad taxonomic groups, is poorly understood. Using a unique global database on consumer and resource body sizes, we show that the mean body-size ratios of aquatic herbivorous and detritivorous consumers are several orders of magnitude larger than those of carnivorous predators. Carnivorous predator-prey body-size ratios vary across different habitats and predator and prey types (invertebrates, ectotherm, and endotherm vertebrates). Predator-prey body-size ratios are on average significantly higher (1) in freshwater habitats than in marine or terrestrial habitats, (2) for vertebrate than for invertebrate predators, and (3) for invertebrate than for ectotherm vertebrate prey. If recent studies that relate body-size ratios to interaction strengths are general, our results suggest that mean consumer-resource interaction strengths may vary systematically across different habitat categories and consumer types.
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| 2. |
- Brose, Ulrich, et al.
(författare)
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Body sizes of consumers and their resources
- 2005
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Ingår i: Ecology. - : Ecological Society of America. - 0012-9658 .- 1939-9170. ; 86:9, s. 2545-2545
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Tidskriftsartikel (refereegranskat)abstract
- Trophic information—who eats whom—and species’ body sizes are two of the most basic descriptions necessary to understand community structure as well as ecological and evolutionary dynamics. Consumer–resource body size ratios between predators and their prey, and parasitoids and their hosts, have recently gained increasing attention due to their important implications for species’ interaction strengths and dynamical population stability. This data set documents body sizes of consumers and their resources. We gathered body size data for the food webs of Skipwith Pond, a parasitoid community of grass-feeding chalcid wasps in British grasslands; the pelagic community of the Benguela system, a source web based on broom in the United Kingdom; Broadstone Stream, UK; the Grand Caric¸aie marsh at Lake Neuchaˆtel, Switzerland; Tuesday Lake, USA; alpine lakes in the Sierra Nevada of California; Mill Stream, UK; and the eastern Weddell Sea Shelf, Antarctica. Further consumer–resource body size data are included for planktonic predators, predatory nematodes, parasitoids, marine fish predators, freshwater invertebrates, Australian terrestrial consumers, and aphid parasitoids. Containing 16 807 records, this is the largest data set ever compiled for body sizes of consumers and their resources. In addition to body sizes, the data set includes information on consumer and resource taxonomy, the geographic location of the study, the habitat studied, the type of the feeding interaction (e.g., predacious, parasitic) and the metabolic categories of the species (e.g., invertebrate, ectotherm vertebrate). The present data set was gathered with the intent to stimulate research on effects of consumer–resource body size patterns on food-web structure, interaction-strength distributions, population dynamics, and community stability. The use of a common data set may facilitate cross-study comparisons and understanding of the relationships between different scientific approaches and models.
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| 3. |
- Lindström, Tom, 1977-, et al.
(författare)
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Splitting the tail of the displacement kernel shows the unimportance of kurtosis
- 2008
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Ingår i: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 89:7, s. 1784-1790
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Tidskriftsartikel (refereegranskat)abstract
- Animals disperse in space through different movement behaviors, resulting in different displacement distances. This is often described with a displacement kernel where the long-distance dispersers are within the tail of the kernel. A displacement with a large proportion of long-distance dispersers may have impact on different aspects of spatial ecology such as invasion speed, population persistence, and distribution. It is, however, unclear whether the kurtosis of the kernel plays a major role since a fatter tail also influences the variance of the kernel. We modeled displacement in landscapes with different amounts and configurations of habitats and handled kurtosis and variance separately to study how these affected population distribution and transition time. We conclude that kurtosis is not important for any of these aspects of spatial ecology. The variance of the kernel, on the other hand, was of great importance to both population distribution and transition time. We argue that separating variance and kurtosis can cast new light on the way in which long-distance dispersers are important in ecological processes. Consequences for empirical studies are discussed.
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| 4. |
- Wootton, Kate L., et al.
(författare)
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Food webs coupled in space : Consumer foraging movement affects both stocks and fluxes
- 2023
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Ingår i: Ecology. - : John Wiley & Sons. - 0012-9658 .- 1939-9170. ; 104:8
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Tidskriftsartikel (refereegranskat)abstract
- The exchange of material and individuals between neighboring food webs is ubiquitous and affects ecosystem functioning. Here, we explore animal foraging movement between adjacent, heterogeneous habitats and its effect on a suite of interconnected ecosystem functions. Combining dynamic food web models with nutrient-recycling models, we study foraging across habitats that differ in fertility and plant diversity. We found that net foraging movement flowed from high to low fertility or high to low diversity and boosted stocks and flows across the whole loop of ecosystem functions, including biomass, detritus, and nutrients, in the recipient habitat. Contrary to common assumptions, however, the largest flows were often between the highest and intermediate fertility habitats rather than highest and lowest. The effect of consumer influx on ecosystem functions was similar to the effect of increasing fertility. Unlike fertility, however, consumer influx caused a shift toward highly predator-dominated biomass distributions, especially in habitats that were unable to support predators in the absence of consumer foraging. This shift resulted from both direct and indirect effects propagated through the interconnected ecosystem functions. Only by considering both stocks and fluxes across the whole loop of ecosystem functions do we uncover the mechanisms driving our results. In conclusion, the outcome of animal foraging movements will differ from that of dispersal and diffusion. Together we show how considering active types of animal movement and the interconnectedness of ecosystem functions can aid our understanding of the patchy landscapes of the Anthropocene.
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