From Individuals to Ecosystems 4th Edition - Chapter 20 doc

... dominated by either top-down or bottom-up control?’ (Note again, though, that even when top-down control ‘dominates’, top-down and bottom-up control are expected to alternate from trophic level to trophic ... subject to bottom-up control (abundance determined by their resources): a standard predator–prey interaction. In turn, the plants are also subject to bottom-up control, havin...

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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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... virus is blood-borne and is transmitted from host to host by blood-feeding insect vectors. In Australia in the first 20 years after its introduction, the main vectors were mosquitoes (especially ... rabies since the dis- ease has yet to cross the English Channel from mainland Europe, but there has been a strong desire to eliminate rabies from the European mainland too (Pastoret &...

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... Chamaephytes or MediterraneanDesert Phanerophyte Chamaephyte Hemicryptophyte Cryptophyte Therophyte Phanerophyte Chamaephyte Hemicryptophyte Cryptophyte Therophyte 80 60 40 20 0 Percent of total flora Temperate Arctic 80 60 40 20 0 Percent of total flora Tropical Phanerophyte Chamaephyte Hemicryptophyte Cryptophyte Therophyte Phanerophyte Chamaephyte Hemicryptophyte Cryptophyte Therophyte...

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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 ... example, a sea height 15 20 cm below average equates to a temperature anomaly of approximately 2–3°C. (Image from http: //topex-www.jpl.nasa.gov/science/images/el-nino-la-nina.jpg.)...

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... (After Loladze, 200 2.) EIPC03 10/24/05 1:47 PM Page 73 •••• (b) Diurnal cycles 0 5 Poona (India) 18°31′ N 0 5 201 24 201 24 201 24 201 24 201 24 201 24 201 24 201 24 201 24 201 24 201 24 201 24 Time (h) Bergen ... 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...

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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 ... population to describe a group of individuals of one species under investigation. What actually constitutes a popula- tion, though, will vary from species to species and f...

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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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... scale) (a) 2 4 10 20 40 100 200 1 2 4 10 20 40 100 200 x 2 (log scale) 1 0 10 100 Mean seed yield per plot (log scale) 1 x 2 (log scale) (b) 2 4 10 20 40 100 200 1 2 4 10 20 40 100 200 x 1 (log ... result from height differences, with one species able to completely over-top another and preempt access to light (Freckleton & Watkinson, 200 1). In a similar vein, De...

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