tailieunhanh - From Individuals to Ecosystems 4th Edition - Chapter 8

Part 2 Species Interactions Introduction The activity of any organism changes the environment in which it lives. It may alter conditions, as when the transpiration of a tree cools the atmosphere, or it may add or subtract resources from the environment that might have been available to other organisms | Introduction The activity of any organism changes the environment in which it lives. It may alter conditions as when the transpiration of a tree cools the atmosphere or it may add or subtract resources from the environment that might have been available to other organisms as when that tree shades the plants beneath it. In addition though organisms interact when individuals enter into the lives of others. In the following chapters 8-15 we consider the variety of these interactions between individuals of different species. We distinguish five main categories competition predation parasitism mutualism and detritivory although like most biological categories these five are not perfect pigeon-holes. In very broad terms competition is an interaction in which one organism consumes a resource that would have been available to and might have been consumed by another. One organism deprives another and as a consequence the other organism grows more slowly leaves fewer progeny or is at greater risk of death. The act of deprivation can occur between two members of the same species or between individuals of different species. We have already examined intraspecific competition in Chapter 5. We turn to interspecific competition in Chapter 8. Chapters 9 and 10 deal with various aspects of predation though we have defined predation broadly. We have combined those situations in which one organism eats another and kills it such as an owl preying on mice and those in which the consumer takes only part of its prey which may then regrow to provide another bite another day grazing . We have also combined herbivory animals eating plants and carnivory animals eating animals . In Chapter 9 we examine the nature of predation . what happens to the predator and what happens to the prey paying particular attention to herbivory because of the subtleties that characterize the response of a plant to attack. We also discuss the behavior of predators. Then in Chapter 10 we examine the consequences