Chapter 13: Ecology

13.1 Ecologists Study Relationships KEY CONCEPT Ecology - is the study of the relationships among organisms and their environment.

Ecologists study environments at different levels of organization. 13.1 Ecologists Study Relationships Ecologists study environments at different levels of organization.

An organism is an individual living thing, such as an alligator. 13.1 Ecologists Study Relationships An organism is an individual living thing, such as an alligator. Organism

A population is a group of the same species that lives in one area. 13.1 Ecologists Study Relationships A population is a group of the same species that lives in one area. Population Organism

13.1 Ecologists Study Relationships A community is a group of different species (populations) that live together in one area. Community Population Organism

13.1 Ecologists Study Relationships An ecosystem includes all of the organisms as well as the climate, soil, water, rocks and other nonliving things in a given area. Ecosystem Ecosystem Community Population Organism

Biome 13.1 Ecologists Study Relationships A biome is a major regional or global community of organisms characterized by the climate conditions and plant communities that thrive there. Ecosystem Community Population Organism

13.2 Biotic & Abiotic Factors KEY CONCEPT Every ecosystem includes both living and nonliving factors.

Biotic factors are living things. plants animals fungi bacteria 13.2 Biotic & Abiotic Factors Biotic factors are living things. plants animals fungi bacteria plants

Abiotic factors are nonliving things. 13.2 Biotic & Abiotic Factors Abiotic factors are nonliving things. moisture temperature wind sunlight Soil Water Rocks moisture sunlight

Changing one factor in an ecosystem can affect many other factors. 13.2 Biotic & Abiotic Factors Changing one factor in an ecosystem can affect many other factors. Biodiversity is the assortment, or variety, of living things in an ecosystem. Rain forests have more biodiversity than other locations in the world.

13.2 Biotic & Abiotic Factors A keystone species is a species that has an unusually large effect on its ecosystem. keystone

Keystone species form and maintain a complex web of life. 13.2 Biotic & Abiotic Factors Keystone species form and maintain a complex web of life. creation of wetland ecosystem increased waterfowl Population increased fish population nesting sites for birds keystone species

KEY CONCEPT Life in an ecosystem requires a source of energy. 13.3 Energy in Ecosystems KEY CONCEPT Life in an ecosystem requires a source of energy.

Producers provide energy for other organisms in an ecosystem. 13.3 Energy in Ecosystems Producers provide energy for other organisms in an ecosystem. Producers get their energy from non-living resources. (The SUN) Producers are also called autotrophs because they make their own food. Plants

carbon dioxide + water + hydrogen sulfide + oxygen 13.3 Energy in Ecosystems Photosynthesis = producers use sunlight as an energy source. carbon dioxide + water + hydrogen sulfide + oxygen sugar + sulfuric acid

Also called heterotrophs … they feed off of different things. 13.3 Energy in Ecosystems Consumers organisms that get their energy by eating other living or once-living resources. Also called heterotrophs … they feed off of different things.

13.4 Food Chains & Webs KEY CONCEPT Food chains and food webs model the flow of energy in an ecosystem.

13.4 Food Chains & Webs A food chain follows the connection between one producer & a single chain of consumers within an ecosystem. DESERT COTTONTAIL GRAMA GRASS HARRIS’S HAWK

Consumers are not all alike. 13.4 Food Chains & Webs Consumers are not all alike. Herbivores eat only plants. Carnivores eat only animals. Omnivores eat both plants and animals. Detritivores eat dead organic matter. Decomposers are detritivores that break down organic matter into simpler compounds. carnivore decomposer Herbivore

Trophic levels are the nourishment levels in a food chain. 13.4 Food Chains & Webs Trophic levels are the nourishment levels in a food chain. Primary consumers are herbivores that eat producers. Secondary consumers are carnivores that eat herbivores. Tertiary consumers are carnivores that eat secondary consumers.

13.4 Food Chains & Webs A food web emphasizes complicated feeding relationships & energy flow in an ecosystem.

13.4 Food Chains & Webs

Energy Flows through an Ecosystem and Nutrients Cycle in an Ecosystem. 13.5 Nutrient Cycles Energy Flows through an Ecosystem and Nutrients Cycle in an Ecosystem. 2. the Primary Nutrient Cycles:     A. The Water Cycle        B. The Nitrogen Cycle

Water is crucial to Life. Cells contain 70 to 90 percent water. 13.5 Nutrient Cycles THE WATER CYCLE Water is crucial to Life. Cells contain 70 to 90 percent water. most of Life’s reactions occur in water.

Water is found in 3 Reservoirs 13.5 Nutrient Cycles Water is found in 3 Reservoirs Bodies of Water (Lakes, Rivers, Streams, & Oceans) Atmosphere (in the form of Water Vapor.) Underground (“Ground Water”) The Movement of Water between these different reservoirs is known as the Water Cycle.

The Water Cycle Usually Consists of the following steps: EVAPORATION 13.5 Nutrient Cycles The Water Cycle Usually Consists of the following steps: EVAPORATION TRANSPIRATION CONDENSATION PRECIPITATION RUN OFF (or RETURN)

EVAPORATION from lakes, rivers, and oceans. 13.5 Nutrient Cycles EVAPORATION from lakes, rivers, and oceans. 

TRANSPIRATION from plants and trees. 13.5 Nutrient Cycles TRANSPIRATION from plants and trees.

CONDENSATION – Cloud Formation 13.5 Nutrient Cycles CONDENSATION – Cloud Formation

PRECIPITATION – Rain, Snow, Sleet, Hail. 13.5 Nutrient Cycles PRECIPITATION – Rain, Snow, Sleet, Hail.

RUN OFF, or RETURNED back into the Cycle. 13.5 Nutrient Cycles RUN OFF, or RETURNED back into the Cycle.

13.5 Nutrient Cycles THE NITROGEN CYCLE ALL Organisms need Nitrogen, to make Proteins and Nucleic Acids. (DNA & RNA) Most Nitrogen is found in the Atmosphere and most living things can’t use it. ALL Organisms rely on Bacteria to change Nitrogen Gas into a Usable Form.

13.5 Nutrient Cycles Conversion of Nitrogen Gas to Ammonia by bacteria is called Nitrogen Fixation. Bacteria live in the soil and in the roots of some kinds of plants, such as beans, peas, clover, and alfalfa. They have Enzymes that can break the atmospheric N2 bonds and form Ammonia (NH3).

Nitrogen Cycle

Then consumers obtain nitrogen from eating plants and animals. 13.5 Nutrient Cycles Ammonia can be absorbed by plants from the soil, and used to make proteins Then consumers obtain nitrogen from eating plants and animals.

Decomposers return Nitrogen back to the soil… 13.5 Nutrient Cycles Decomposers return Nitrogen back to the soil… from the remains of dead plants and animals.  from animal waste (dung & urine) This process is known as AMMONIFICATION.

13.5 Nutrient Cycles DENITRIFICATION is when Bacteria break down Nitrates and release Nitrogen Gas back into the Atmosphere.

13.5 Nutrient Cycles In Conclusion: Plants DEPEND on nitrogen fixing bacteria, and all other organisms including YOU, DEPEND ON THEM!

13.6 Pyramid Models KEY CONCEPT Pyramids model the distribution of energy and matter in an ecosystem.

13.6 Pyramid Models Energy pyramids compare energy used by producers and other organisms on different levels called trophic levels. Between each level of an energy pyramid, up to 90% of the energy is lost into the atmosphere as HEAT. Only 10% of the energy at each tier is transferred from one trophic level to the next. energy lost energy transferred

13.6 Pyramid Models Biomass Pyramid - is a measure of the total dry mass of organisms in a given area. tertiary consumers secondary primary producers 75 g/m2 150g/m2 675g/m2 2000g/m2

13.6 Pyramid Models A pyramid of numbers shows the numbers of individual organisms at each trophic level in an ecosystem. A vast number of producers are required to support even a few top level consumers. tertiary consumers secondary primary producers 5 5000 500,000 5,000,000