34.1-34.4: The Biosphere

34.1 Introduction to the Study of Ecology Ecology is the scientific study of the interactions of organisms with their environments. What could an ecologist study about the red fox? Student Misconceptions and Concerns  Students may confuse the terms ecology and environmentalism. The science of ecology and the environmental issues that it often raises are related but distinct processes. Teaching Tips  In the first chapter of the text, Module 1.2 introduces the levels of biological organization extending from an atom to the biosphere. Reviewing these with students will help them to place these ecology chapters in context.

34.1 Introduction to the Study of Ecology Organisms can potentially be affected by many different variables, grouped into two major types. Biotic factors include all of the organisms in an area, the living component of the environment. Abiotic factors are the environment’s nonliving component, the physical and chemical factors. An organism’s habitat includes the biotic and abiotic factors present in its surroundings.

Biotic or Abiotic? http://www.arkive.org/brown-bear/ursus-arctos/video- 09c.html Biotic factors: 1. 2. Abiotic factors: What are the biotic and abiotic factors in this video? 4

The Biosphere’s Levels of Organization Ecologists study environmental interactions at the levels of the organism, population, a group of individuals of the same species living in a particular geographic area, community, an assemblage of all the populations of organisms living close enough together for potential interaction, and ecosystem, both the abiotic and biotic components of the environment. Student Misconceptions and Concerns  Students may confuse the terms ecology and environmentalism. The science of ecology and the environmental issues that it often raises are related but distinct processes. Teaching Tips  In the first chapter of the text, Module 1.2 introduces the levels of biological organization extending from an atom to the biosphere. Reviewing these with students will help them to place these ecology chapters in context.

The Biosphere’s Levels of Organization Organismal ecology (individual) Population ecology (group of individuals of a species) Community ecology (all organisms in a particular area) Ecosystem ecology (all organisms and abiotic factors)

The Biosphere’s Levels of Organization Some ecologists take a wider perspective by studying landscapes, arrays of ecosystems usually visible from the air as distinctive patches. The biosphere extends from the atmosphere several kilometers above Earth to the depths of the oceans and is all of Earth that is inhabited by life. Student Misconceptions and Concerns  Students may confuse the terms ecology and environmentalism. The science of ecology and the environmental issues that it often raises are related but distinct processes. Teaching Tips  In the first chapter of the text, Module 1.2 introduces the levels of biological organization extending from an atom to the biosphere. Reviewing these with students will help them to place these ecology chapters in context.

34.3 Abiotic factors influence life in the biosphere The most important abiotic factors that determine the biosphere’s structure and dynamics include the energy source, usually solar energy, temperature, abundance and type of water, inorganic nutrients, other aquatic factors such as availability of oxygen, and other terrestrial factors including wind and fire. Student Misconceptions and Concerns  Students may confuse the terms ecology and environmentalism. The science of ecology and the environmental issues that it often raises are related but distinct processes. Teaching Tips  In general, the sun is the primary source of energy input to ecosystems. Hydrothermal vent communities are a clear exception. Some students might enjoy researching additional details about these ecosystems and the roles they might have played in the early evolution of life on Earth. One excellent source of good information about hydrothermal vent communities is www.csa.com/discoveryguides/vent/websites.php. Active Lecture Tips  As a class focusing exercise, consider challenging students to work in pairs to make lists of all the abiotic components in a given ecosystem, perhaps in regards to the local area just outside your campus building. Alternately, students may work in small groups after class and turn in lists as a short homework assignment. The class might enjoy a bit of competition and a review of what groups thought of after the assignment is turned in.