Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
The Biosphere What is Ecology? & Energy Flow Introduction • Ecology = the study of interactions among organisms and their environment. • Biosphere = Parts of the planet in which all life exists. – Land, water, air 1 Levels of organization • Species = a group of organisms that can breed and produce fertile offspring. • Population = groups of organisms that belong to the same species and live in the same area. • Community = different populations that live together in a defined area. • Ecosystem = community of organisms including their non-living physical environment. • Biome = group of ecosystems that have the same climate and similar communities 2 Energy Flow - Producers • Autotrophs = plants, some algae and certain bacteria capture energy and use that energy to produce their own food. – Plants = the primary autotrophs found on the land. – Algae = The primary autotrophs found in aquatic (water) environments such as oceans, lakes, ponds. – Cyanobacteria = photosynthetic bacteria found in certain wet environments. • Autotrophs are producers! Energy Flow - Producers • Photosynthesis = process of using energy in sunlight to convert water and carbon dioxide into carbohydrates and oxygen. 3 Energy Flow - Producers • Chemosynthesis = When organisms use chemical energy to produce carbohydrates. • Performed by many types of bacteria – Methanogens produce methane. – Halophiles live in high salt water concentrations. – Thermoacidophiles live in acidic, sulfur rich, high temperature environments. Energy Flow - Consumers • Heterotrophs = organisms that rely on other organisms for their energy and food supply. • Heterotrophs are consumers! 4 Energy Flow - Consumers • Herbivores = An organism that obtains energy by eating plants. • Carnivores = An organism that obtains energy by eating other animals. • Omnivores = An organism that eats both plants and animals. Energy Flow - Consumers • Dentrivores = Organisms that feed of dead and decaying animal or plant material (detritus). – Examples: earthworms, termites, slugs, snails, maggots. • Decomposers = Breaks down organic matter into inorganic matter. – Examples: fungi and bacteria. 5 Feeding relationships - Food Chains • Food chain = A series of steps in which organisms transfer energy by eating and being eaten. 6 Feeding relationships - Food Webs • Food web = links all of the food chains in an ecosystem together. 7 Feeding relationships - Food Webs • Each step in a food chain is called a trophic level. – 1st trophic level = producers – 2nd, 3rd, 4th… trophic levels = Consumers 8 Ecological Pyramids • Ecological pyramid = diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web. – Energy pyramid – Biomass pyramid – Pyramid of numbers 9 Ecological Pyramids = Energy Pyramid • Only about 10% of the energy available within one trophic level is transferred to the next trophic level. • Energy is used for respiration, movement, reproduction. • Some energy is lost as heat. 10 Ecological Pyramids = Biomass • Biomass = Total amount of living tissue within a given trophic level. • Represents the amount of potential food available for each trophic level. • Expressed in grams. 11 Ecological Pyramids = Pyramid of Numbers • Based on the numbers of individual organisms. • Not always shaped like a pyramid. – Sometimes there are fewer producers than there are consumers. 12 13