Copyright Pearson Prentice Hall 3-1 What Is Ecology? Photo Credit: ©Bruce Coleman, LTD/Natural Selection Copyright Pearson Prentice Hall

Interactions and Interdependence Ecology is the scientific study of interactions among organisms and between organisms and their environment, or surroundings. Copyright Pearson Prentice Hall

Interactions and Interdependence The biosphere contains the combined portions of the planet in which all of life exists, including: land water air, or atmosphere The biosphere extends from about 8 kilometers above Earth's surface to as far as 11 kilometers below the surface of the ocean. Copyright Pearson Prentice Hall

Interactions and Interdependence Interactions within the biosphere produce a web of interdependence between organisms and the environment in which they live. The interdependence of life on Earth contributes to an ever-changing, or dynamic, biosphere. Copyright Pearson Prentice Hall

Levels of Organization What different levels of organization do ecologists study? Copyright Pearson Prentice Hall

Levels of Organization To understand relationships within the biosphere, ecologists ask questions about events and organisms that range in complexity from a single individual to the entire biosphere. The levels of organization that ecologists study include: individuals, populations, communities, ecosystems, and biomes. Copyright Pearson Prentice Hall

Levels of Organization Biosphere Biome Ecosystem Community The study of ecology ranges from the study of an individual organism to populations, communities, ecosystems, biomes—and, finally, to the entire biosphere. The information that ecologists gain at each level contributes to our understanding of natural systems. Population Individual Copyright Pearson Prentice Hall

Levels of Organization A species is a group of organisms so similar to one another that they can breed and produce fertile offspring. Populations are groups of individuals that belong to the same species and live in the same area. Communities are assemblages of different populations that live together in a defined area. Copyright Pearson Prentice Hall

Levels of Organization An ecosystem is a collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment. A biome is a group of ecosystems that have the same climate and similar dominant communities. The highest level of organization that ecologists study is the entire biosphere itself. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecological Methods What methods are used to study ecology? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecological Methods Ecological Methods Regardless of the tools they use, scientists conduct modern ecological research using three basic approaches: observing experimenting modeling All of these approaches rely on the application of scientific methods to guide ecological inquiry. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecological Methods Observing  Observing is often the first step in asking ecological questions. Some observations are simple. Others are complex and may form the first step in designing experiments and models. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecological Methods Experimenting Experiments can be used to test hypotheses. An ecologist may set up an artificial environment in a laboratory to imitate and manipulate conditions that organisms would encounter in the wild. Other experiments are conducted within natural ecosystems. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecological Methods Modeling Ecologists make models to gain insight into complex phenomena. Many ecological models consist of mathematical formulas based on data collected through observation and experimentation. The predictions made by ecological models are often tested by further observations and experiments. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3-1 The combined portions of the planet in which life exists, including land, water, and the atmosphere, form the biosphere. community. species. ecosystem. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3-1 A group of organisms that can breed and produce fertile offspring is known as a(an) ecosystem. species. biome. community. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3-1 Compared to a community, an ecosystem includes the nonliving, physical environment as well as the community. only the physical environment of an area without the organisms. the entire biome but not the biosphere. only one of the populations within the community. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3-1 An ecological method that uses mathematical formulas based on data collected is observing. experimenting. modeling. hypothesizing. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 3-1 An ecologist marks out an area in a specific ecosystem and proceeds to identify the number of insect species in the area. This is an example of ecological experimentation. observation. modeling. inference. Copyright Pearson Prentice Hall

4-2 What Shapes an Ecosystem? Photo Credit: ©Michael Fogden/DRK PHOTO Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Biotic and Abiotic Factors Ecosystems are influenced by a combination of biological and physical factors. Biotic – biological factors Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Physical, or nonliving, factors that shape ecosystems are called abiotic factors. Abiotic factors include: temperature precipitation humidity wind nutrient availability soil type sunlight Copyright Pearson Prentice Hall

Biotic and Abiotic Factors How do biotic and abiotic factors influence an ecosystem? Copyright Pearson Prentice Hall

Biotic and Abiotic Factors The area where an organism lives is called its habitat. A habitat includes both biotic and abiotic factors. Copyright Pearson Prentice Hall

Organisms are adapted to abiotic and biotic factors by natural selection. Species exist in a given place because they evolve there or disperse there Unique adaptations that fit a particular environment allow organisms to survive there Organisms vary greatly in their ability to tolerate fluctuations and long-term changes in their environment

Copyright Pearson Prentice Hall The Niche A niche is the full range of physical and biological conditions in which an organism lives and the way in which the organism uses those conditions. No two species can share the same niche in the same habitat Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 4-3 Biomes Photo Credit: ©Michael Fogden/DRK PHOTO Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall A biome is a complex of terrestrial (or aquatic) communities that covers a large area and is characterized by certain soil and climate conditions and particular assemblages of plants and animals. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Variations in plants and animals help different species survive under different conditions in different biomes. Plants and animals exhibit variations in tolerance, or the ability to survive and reproduce under conditions that differ from their optimal conditions. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Biomes and Climate Biomes and Climate The climate of a region is an important factor in determining which organisms can survive there. Within a biome, temperature and precipitation can vary over small distances. The climate in a small area that differs from the climate around it is called a microclimate. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Two components of climate, temperature and precipitation, can be summarized in a graph called a climate diagram. Average Precipitation (mm) Average Temperature (°C) Climate diagrams show the average temperature and precipitation at a given location during each month of the year. In this graph, and the others to follow, temperature is plotted as a red line. Precipitation is shown as vertical purple bars. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall The Major Biomes The world's major biomes include: tropical rain forest tropical dry forest tropical savanna desert temperate grassland temperate woodland and shrubland temperate forest northwestern coniferous forest boreal forest tundra Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall The Major Biomes What are the unique characteristics of the world's major biomes? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall The Major Biomes Biomes are defined by a unique set of abiotic factors—particularly climate—and a characteristic assemblage of plants and animals. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall The Major Biomes 60°N 30°N 0° Equator 30°S 60°S Tropical rain forest Temperate grassland This map shows the locations of the world’s major biomes. Other parts of Earth’s surface are classified as mountains or ice caps. Each biome has a characteristic climate and community of organisms. Temperate forest Northwestern coniferous forest Tropical dry forest Desert Temperate woodland and shrubland Boreal forest (Taiga) Tropical savanna Tundra Mountains and ice caps Copyright Pearson Prentice Hall