Consider the plants, animals, and other organisms present in a natural area near you, and then do the following: (a) Imagine how the area may have undergone ecological succession, and (b) analyze the population-balancing mechanisms that are operating

Question

among the various organisms. Choose one species, and predict what will happen to it if two or three other native species are removed from the area. Then predict what will happen to your chosen species if two or three foreign species are introduced into the area.

Answer 1

The answers to these questions will vary depending upon the area of the country. (a) Ecological succession may be caused by grass fires (near a road, next to picnic areas), erosion (construction sites, logging, agricultural fields), clearing of land (building construction, road building), or demolition of buildings. Once you have identified possible ecological succession causes, it will be possible to consider the plant and animal changes that may have taken place. For example, grasses, pine trees, or invasive species could be favored. (b) Population balance mechanisms that should be considered are territoriality, interspecies plant competition, missing predators, and grazing by herbivores. Most species will not be directly impacted if another species is removed or introduced. You will see direct impacts if the species removed is a food source, a competitor, a predator, and
so forth. You will see direct impacts from an introduced species if the introduced species competes for the same food, eats or provides food for the species you are evaluating, or competes for such needs as nesting sites and territory.