Chapter 3 The Biosphere Section 1 What is Ecology? (pp. 63 – 65) Section 2 Energy Flow (pp. 67 – 73) Updated Nov 2004 Created by C. Ippolito November 2004

What is Ecology? What different levels of organization do ecologists study? What methods are used to study ecology? Updated Nov 2004 Created by C. Ippolito November 2004

Interactions and Interdependence Ecology – studies the interactions of organisms and their surroundings. eco – Greek word for house Logy – Greek word for study of Ernst Haeckel saw the living world as a household with each organism having a role to play Biosphere – everywhere on Earth that life can exist Updated Nov 2004 Created by C. Ippolito November 2004

Levels Within Levels An ecosystem is a collection of all the organisms that live in a particular place, together with their nonliving, or physical, environment. Within an ecosystem, there are several levels of organization. Your school and its grounds are similar to an ecosystem. Go to Section: Updated Nov 2004 Created by C. Ippolito November 2004

Levels of Organization Ecologists can study relationships from the level of a single cell to the whole biosphere Species – group that can breed and produce fertile offspring Population – group of same species in the same area Community – different populations living together in a specific area Ecosystem – all organisms and their nonliving, or physical surroundings Biome – group of ecosystems with same climate and dominant communities Updated Nov 2004 Created by C. Ippolito November 2004

Ecological Methods Modern ecological research involves THREE (3) basic approaches: Observing What species live here? How many are here? Experimenting Use artificial environment in lab (aquaria, terrariums, etc.) Modeling Mathematical formulas based on observations to predict long range effects Updated Nov 2004 Created by C. Ippolito November 2004

Energy Flow Where does the energy for life processes come from? How does energy flow through living systems? How efficient is the transfer of energy among organisms in an ecosystem? Updated Nov 2004 Created by C. Ippolito November 2004

Producers Sunlight is the main energy source. Less than 1% is used by organisms Autotrophs (producers) – use energy to form food Photosynthesis – use energy from sunlight to form complex organic chemicals from simple inorganic chemicals Chemosynthesis – use chemical energy from hydrogen sulfide or heat vents to form complex organic chemicals from simple inorganic chemicals Updated Nov 2004 Created by C. Ippolito November 2004

Consumers Heterotrophs (consumers) - Cannot harness energy directly; acquire it from other organisms. Herbivores – obtain energy by eating plants Carnivores - obtain energy by eating animals Omnivores - obtain energy by eating both Detritivores - obtain energy by eating plant and animal remains (detritus) Decomposers – change organic matter back into inorganic matter Updated Nov 2004 Created by C. Ippolito November 2004

Feeding Relationships Energy flows in one direction in an ecosystem Sun  autotrophs heterotrophs Food Chain – series of steps in which organisms transfer energy by eating and being eaten Updated Nov 2004 Created by C. Ippolito November 2004

Food Web A complex interaction of feeding relationships Trophic Level step in a food chain or food web Updated Nov 2004 Created by C. Ippolito November 2004

Regents Example of Food Web Updated Nov 2004 Created by C. Ippolito November 2004

Ecological Pyramids Diagrams used to show relative amounts of energy or matter at each trophic level in a food chain or food web Energy Pyramid – only 10% of energy transfers from one level to the next! Biomass Pyramid – total amount of living tissue at each level Numbers Pyramid – number of individuals at each level Updated Nov 2004 Created by C. Ippolito November 2004

Energy Pyramids Updated Nov 2004 Created by C. Ippolito November 2004

Biomass Pyramid Updated Nov 2004 Created by C. Ippolito November 2004

Numbers Pyramid Updated Nov 2004 Created by C. Ippolito November 2004

Regents Pyramids Updated Nov 2004 Created by C. Ippolito November 2004