Ecology Chapters Chapter 18 The Ecology of Organisms and Populations Chapter 19: Communities and Ecosystems Chapter 20: Human Impact on the Environment 1. Define ecology. ---scientific study of the interactions between organisms and their environments ---provides a basic understanding of how natural processes and organisms interact 2. Define a population with examples. ---a group of individuals of the same species living in a particular geographic area --striped mice in a particular area, human beings in Pendleton 3. Define community with examples. ---consists of all the organisms that inhabit a particular area ---is an assemblage of populations of different species --living room; TriCounty; Pendleton 4. Define ecosystem with examples. ---includes all the abiotic (nonliving and physical factors) factors in addition to the community of species in a certain area --living room, Tricounty, Pendleton 5. Define biomes. ---major types of ecosystems that cover large geographic regions 6. Discuss community interactions in terms of producers and different levels of consumers. ---species of ecosystem divided into different tropic levels based on their main source of nutrition ---trophic level that supports all others is the producer ---all consumers are dependent upon the producers 7. Distinguish between herbivores and carnivores. 8. Distinguish the food chain and the food web. ---food chain is sequence of food transfer from trophic level to trophic level ---food web is the branched feeding relationships in an ecosystem 9. Describe one terrestrial food chain. ---plant-->grasshopper-->mouse-->snake-->hawk 10. Describe one aquatic food chain. ---phytoplankton-->zooplankton-->minnow-->tuna-->killer whale 11. Discuss energy flow between levels in a food chain. ---approximately 90% of energy is lost from one level to the next ---means only 10% of chemical energy available at each trophic level is converted to new biomass at the trophic level above it ---let’s talk about this and its implications for some very tough decisions for the future 12. Construct an energy pyramid based on producers and different levels of consumers. 13. Explain how humans eat on several different trophic levels in a meal involving steak, potatoes, tossed salad, bread, and iced tea. 14. Define biome including the usual limiting factors in a biome. ---major types of ecosystems that cover large geographic regions ---**biome characterized by TYPE of biological community, not a collection of certain species of organisms ---usual limiting factor is the climate, with temperature and rainfall often key factors determining kind of biome existing in particular area 15. Recognize descriptions of the following biomes: Deciduous forest, grassland, savanna, desert, taiga, temperate rain forest, and tundra. ---deciduous forest occur where sufficient moisture to support growth of large trees; deciduous trees drop their leaves before winter; recover from disturbance quicker than drier biomes ---grassland are characterized by seasonal drought, occasional fires, and by grazing by large mammals which prevents establishment of woody shrubs and trees; grassland soil is deep and rich in nutrients and most has been converted to farmland ---savanna is grassland with scattered trees; dominant herbivores are insects (ants and termites); fire is important abiotic factor and dominant species are fire adapted; periods of drought followed by rainy season ---desert characterized by very sparse rainfall (<30 cm year); both hot and cold deserts; most plants adapted to “store” water; some animals do NOT require water to drink; behavioral modifications key to animal life ---taiga (northern coniferous forest) is largest terrestrial biome on Earth; cone-bearing trees dominant; receives heavy snowfall during winter ---temperate rain forest is coastal coniferous forest of U.S. Pacific Northwest (Washington and Oregon); warm, moist air from Pacific Ocean support these unique communities dominated by one or few coniferous trees ---tundra characterized by permafrost (permanently frozen subsoil), bitterly cold temperatures, and high winds; complete absence of trees and other tall plants; covers about 20% of Earth’s land surface; important breeding grounds in short summer 16. Explain why the idea of interaction is inherent in the concept of the community. 17. Define predation with an example. 18. Define parasitism with an example. 19. Define commensalism with an example. 20. Define mutualism with an example. 21. Define symbiosis with an example.