Ecology is the branch of biology that studies the interactions of organisms with one another and with their physical environment.
The two factors that make up the environment of an organism: BIOTIC FACTORS It includes all the living organisms in the environment. ex: Producers Consumers Decomposers ABIOTIC FACTORS Light Heat or solar energy Water Minerals Soil Oxygen Wind etc.
1. POPULATION A population is a group of individuals of the same species existing together in a given area. Ex: *human population in Ankara *squirrel population in ODTÜ forest *volvox population in Eymir lake For example, all of the Great Diving Beetle larvae and adults in the pond.
2. COMMUNITY All the populations of different organisms within agiven areamake up the community. Ex: All of the populations in ODTÜ forest For example, all of the numerous species of micro- organisms, plants and animals living in the pond
3. ECOSYSTEM A certain area in which organisms interact with each other and with their environment. An ecosystem includes a community and its physical environment. Ex: ODTÜ forest Eymir lake The pond ecosystem includes all of the non- living components - the water, the soil surrounding the pond, the mud on the bottom, the weather and microclimate, together with the living community of organisms
4. BIOME One of the major terrestrial ecosystems, characterized by climatic and soil conditions. Biomes are named according to the dominant plant population of them. Tundra Coniferous forest
NICHE The role of a species in an ecosystem. In balanced ecosystem each species occupies its own niche. Ex: Nitrogen fixing bacteria nitrogen fixation Pine tree ODTÜ forest photosynthesis Saprobes in soil decompose dead material
Nutrition in Ecosystem 1.Autotroph: An organism able to make all the complex organic molecules (its own food molecules) using simple inorganic compounds. Ex: Photocynthetic bacteria Algae Plants Chemosynthetic bacteria
Nutrition in Ecosystem An organism that cannot derive energy from photosynthesis or inorganic chemicals, and so must feed on other plants or animals. Ex: Holozoic organisms Saprobes 2.Heterotroph: Most of bacteria Fungi
Nutrition in Ecosystem Organisms take in solid organic food from ingesting other living organisms A) Holozoic organisms: Herbivores CarnivoresOmnivores
Predator Any organism that catches and kills other organisms. Prey Organism that is actively captured and used as food by predators.
Food Chains and Food Webs Food Chain: A series of organisms through which food energy is passed. Producers, consumers and decomposers make up the food chain. All the feeding categories that occur in an ecosystem represent different trophic levels.
Ecological Pyramids Pyramid of biomass: gr/m 2 PRODUCERS HERBIVORES CARNIVORES Because energy is lost at every step of a food chain, the biomass of primary producers tends to be greater than that of the herbivores that consume them, and herbivore biomass is greater than the biomass of the predators.
Producers Herbivores Carnivores Inverted pyramid of biomass in some aquatic ecosystems Ecological Pyramids Pyramid of biomass: gr/m 2
Biological Magnification Certain harmful substances, usually ones not found in nature but introduced by man, may get into plants and/or animals. These poisonous substances may not be broken down in the body or excreted easily, efficiently and quickly. Instead, they accumulate in the tissues, and as the living organism eats more, the concentration of these substances increases and they pass from one trophic level to the next. This phenomenon is called 'Biological magnification'.
97% of the water on earth is in the oceans Only 3% of the water on earth is freshwater About 2.4% of the water on earth is permanently frozen in glaciers and at the polar ice caps About 1/2 of 1 % of the water on earth is groundwater Only about 1/100 of 1% of the water on earth is in the rivers and lakes It takes 39,090 gallons of water to make a new car, including the tires Over 17,000,000 houses use private wells for their drinking water supply A person can live about a month without food, but can live only about 1 week without water