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Question 6: What are the different factors that influence the Green World Hypothesis?

Question 6: What are the different factors that influence the Green World Hypothesis?. By: Mele Moniz Nicole Huffman. Green World Hypothesis. S tates that terrestrial herbivores

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Question 6: What are the different factors that influence the Green World Hypothesis?

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  1. Question 6:What are the different factors that influence the Green World Hypothesis? By: Mele Moniz Nicole Huffman

  2. Green World Hypothesis • States that terrestrial herbivores consume relatively little plant biomass because they are held in check by a variety of factors, including predators, parasites, and disease. • This theory is credited with bringing attention to the role of top-down forces and indirect effects in shaping ecological communities.

  3. Plants • Plants have defenses against herbivores such as noxious chemicals and spines. • Nutrients, not energy supply, usually limit herbivores. Plants give off a low supply of protein, which animals need.

  4. Abiotic Factors • Changes in temperature and moisture will lower the carrying capacity of herbivores so that they're unable to strip an area of its vegetation.

  5. Intraspecific Competition • Limits herbivore numbers because they may battle over territory or mates.

  6. Interspecific Interactions • Such as predation and disease will kill herbivore densities in check. This is said to be the most important limiting factor. - Predators in a food web suppress the abundance of their prey, thereby releasing the next lower trophic level from predation.

  7. On a Related Note…Trophic cascade • Nelson Hairston, Frederick E. Smith, and Lawrence B. Slobodkin are credited with the concept of trophic cascade, despite never using the term. • They argued that predators reduced the number of herbivores and therefore allowed plants to flourish, a.k.a. the green world hypothesis. • Previously , trophodynamics was used to explain the structure of communities using the bottom-up forces, or resource limitation. • Hairston, Smith, and Slobodkin argued that ecological communities acted as food chains with three trophic levels. Other models have expanded and shrunk this model. • Hairston, Smith and Slobodkin formulated their argument in terms of terrestrial food chains, the earliest empirical demonstrations of trophic cascades came from marine and, especially, aquatic ecosystems.

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