Ecology & Ecosystems

Ecology is the study of the interactions between organisms (biotic factors) and their environment (abiotic factors) Abiotic Factors: The environment’s nonliving components that shape the environment: 1.Energy source 2.Temperature 3.Water 4.Gases 5.Soil 6.Nutrient Availability

Energy Source & Temperature Without a constant source of energy, living things die. The primary source of energy for living things on Earth is the Sun. All living organisms have a range of temperature in which they best operate At or below 0 o C and above 45 o C will destroy the enzymes of most organisms.

Water & Gases Water Is essential for all life. It is critical for most chemical reactions, It is necessary for diffusion, it helps maintain body temperature, it helps prevent dehydration. Organisms require certain gases to carry out life processes.

Soil & Nutrient Availability Nutrients are all the chemical substances an organism needs to sustain its life. Many of these nutrients are obtained through the soil by plants, which are then consumed by animals.

Biotic Factors All of the living organisms in an area

Ecology Levels of Organization

Biosphere: The areas on Earth where life is found from about 8 km above the Earth to about 11 km deep in the ocean (on land, in the water or in the atmosphere) Biome: A group of ecosystems with similar climates & organisms. Ecosystem: All the abiotic factors and biotic factors found in a certain place at any time. Community: All the organisms living in a specific area at a specific time. Population: A group of individuals of the same species living in the same area at the same time. Species: A group of organisms so similar that they can breed and produce fertile offspring

Habitat – the place (home) you normally find an organism in its ecosystem. {ex: ducks at a pond} Niche – the role (job) of an organism in its ecosystem. {ex: bees are pollinators for plants) Major Biomes: Polar Ice Caps, Tundra, Taiga {Boreal Forest), Grassland (Savanna), Temperate (Deciduos) Forest, Rainforest, Desert, Highlands, Marine Water & Salt Water.

Energy Flow The sun is the main source of energy for life on earth. < 1 % of all sunlight that reaches earth is used by living organisms. Most of the rest is reflected off as heat energy.

Producers or Autotrophs Photosynthesis is the process where autotrophs use light as an energy source to make their own food. 6CO 2 + 6H 2 O → C 6 H 12 O 6 + 6O 2 Performed on land by plants and in water by algae. Chemosynthesis: using chemical energy to make carbohydrates. Usually performed bacteria found in harsh environments: Ocean vents, volcanoes, and hot-acidic environments.

Consumers or heterotrophs: Must get their energy by eating other organisms Herbivores eat plants. Carnivores eat meatHerbivores eat plants. Carnivores eat meat Omnivores eat both Detrivores eat dead stuffOmnivores eat both Detrivores eat dead stuff plants & animals plants & animals Decomposers chemicallyDecomposers chemically break down decaying stuff break down decaying stuff Herbivores eat plants. Carnivores eat meatHerbivores eat plants. Carnivores eat meat Omnivores eat both Detrivores eat dead stuffOmnivores eat both Detrivores eat dead stuff plants & animals plants & animals Decomposers chemicallyDecomposers chemically break down decaying stuff break down decaying stuff

Food Chains

Food Webs are a complex net of interactions among organisms. (interdependence) Each location or step in a food chain or food web represents a trophic level.

Ecological pyramids Only about ten percent of the energy available within a trophic level is transferred to oragnisms at the next higher level. Pyramid of Numbers

Biomass Pyramids Biomass and numbers