From Individuals to Ecosystems 4th Edition - Chapter 13 potx

... be toxic to the host. 13. 5.2 Ruminant guts The stomach of ruminants comprises a three-part forestomach (rumen, reticulum and omasum) followed by an enzyme- secreting abomasum that is similar to ... serial endosymbiosis theory EIPC13 10/24/05 2:06 PM Page 407 390 CHAPTER 13 13.4.3 Brood site pollination: figs and yuccas Not every insect-pollinated plant pro- vides its pollinator with...

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... dioxide The CO 2 used in photosynthesis is obtained almost entirely from the atmo- sphere, where its concentration has risen from approximately 280 µll −1 in 1750 to about 370 µll −1 today and is still ... feedback from elevated CO 2 concentrations to plant growth, to microbial activity and back to plant growth. The arrows between descriptors indicate causation; the black arrow...

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... times take longer to respond to increases in prey abundance, and longer to recover when reduced to low densities. The same phenomenon occurs in desert communities, where year -to- year variations ... seeds, mealworms, zooplankton relative to fish), it often fails to pre- dict diets of foragers that attack mobile prey (small mammals, fish, zooplankton relative to insect predators)...

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... area showing the gradual change from pasture to cliff conditions. (c) The mean length of stolons produced in the experimental garden from samples taken from the transect. (From Aston & Bradshaw, 1966.) the ... evolutionary history. All species are absent from almost everywhere, and we consider next, in Chapter 2, the ways in which environmental conditions vary from place...

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... sampled from diverse localities in northern USA and Canada, and were tested for freezing tolerance and ability to acclimate to cold. Individuals from the most freeze-tolerant population (from ... environ- mental conditions because water tends to move into organisms from the environment and this needs to be resisted. In marine habitats, the majority of organisms are isotonic...

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... sometimes to pupae, and then to adults; plants pass from seeds to seedlings to photosynthesizing adults; and so on. The different stages are likely to be influenced by different factors and to have ... HISTORIES 131 habitat in seeking to understand life histories. Phylogeny sets limits to an organism’s life history and to its habitat. But the essentially ecological task...

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... therefore trajectories that follow a cohort through time. This is indicated by arrows, pointing from many small, young individuals (bottom right) to fewer, larger, older individuals (top left). Mean ... small population sizes: A to B, B to C) and is small close to the carrying capacity (I to J, J to K), but is large at intermediate densities (E to F). The result is an ‘S...

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... (Murton et al., 1966). Individuals may also gain from living in groups if this helps to locate food, give warning of predators or if it pays for individuals to join forces in fighting off a predator ... attracting individuals to disperse towards one another and forces provoking individuals to disperse away from one another. As we shall see in a later chapter, such compromi...

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... which grows from 1900 to 3000 m. But as colder weather sets in, they travel to lower elevations and from October to May they feed primarily on Bashania fargesii, which grows from 1000 to 2100 m. ... in twelve 5-year age classes through dis- crete 5-year time steps. Values for age-specific survivorship and density-dependent reproductive rates were derived from a thorough data...

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... In plants, for example, this may result from height differences, with one species able to completely over-top another and preempt access to light (Freckleton & Watkinson, 2001). In a similar ... performance was due to improved access to pre- ferred nest sites and consequent decreased losses of nestlings to predators. In the case of virginia’s warblers, but not orange- crowned...

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