Ecology

What is ecology? Ecology- the scientific study of interactions between organisms and their environments.

What do you mean by environment? The environment is made up of two factors: Biotic factors- all living organisms inhabiting the Earth Abiotic factors- nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents)

Organism Population Community Biosphere Ecosystem

OrganismOrganism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual. The lowest level of organization

PopulationPopulation-a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources (ex. food, mates, shelter)

CommunityCommunity- several interacting populations that inhabit a common environment and are interdependent.

EcosystemEcosystem- all living and non-living factors interacting with one another.

BiosphereBiosphere- life supporting portions of Earth composed of air, land, fresh water, and salt water. The highest level of organization

Environment – the natural world that surrounds an organism. Carrying Capacity – maximum number of individual species that an area can hold (support). Sustainable Development – using resources to meet human needs while preserving the environment.

Habitat vs. Niche Niche - the role a species plays in a community (job) Habitat- the place in which an organism lives out its life (address)

Limiting factor- things that prevent a population from growing larger.

Examples of limiting factors- Amount of water Amount of food Temperature Shelter Amount of space

Feeding Relationships There are 3 main types of feeding relationships 1. Producer- Consumer 2. Predator- Prey 3. Parasite- Host

Feeding Relationships Predator – organism that hunts other organisms Prey – organism hunted, killed, and eaten by predator (“if it can’t run away, it isn’t prey!)

Feeding Relationships Producer: all autotrophs (plants) they trap energy from the sun bottom of the food chain Make their own food

Feeding Relationships Consumer: all heterotrophs –Herbivores –Carnivores –Omnivores –Decomposers they ingest food containing the sun’s energy cannot make its own food

Feeding Relationships Herbivores: Eat plants Primary consumers

Feeding Relationships Carnivores: Eat meat Predators –Hunt prey animals for food

Feeding Relationships Scavengers: Eat meat Feed on carrion, dead animals

Feeding Relationships Omnivores: Eat both plants and animals

Feeding Relationships Decomposers: Breakdown the complex compounds of dead and decaying plants and animals into simpler molecules that can be absorbed

Symbiotic Relationships Symbiosis- relationship between two species living closely together 3 Types of symbiosis: 1. Commensalism 2. Parasitism 3. Mutualism

Symbiotic Relationships Commensalism- one species benefits and the other is neither harmed nor helped

Symbiotic Relationships One example of commensalism is the relationship between sharks and remoras. The remoras “hitch a ride” on the sharks and feed on scraps of food left by sharks. The remoras benefit from this relationship while the sharks are unaffected.

Symbiotic Relationships Parasitism- one species benefits (parasite) and the other is harmed (host) Parasite-Host relationship

Symbiotic Relationships An example of parasitism is the relationship between a bright green caterpillar called a tomato hornworm and a female wasp. The female wasp lays tiny eggs on the caterpillar. When the eggs hatch, each young wasp will burrow into the caterpillar’s body. The young wasp will actually eat the caterpillar alive! In a short time, the caterpillar will be almost consumed and will die. When that occurs, the mature wasp will fly away.

Symbiotic Relationships Mutualism- the relationship is beneficial to both species

Symbiotic Relationships An example of mutualism is yourself and a species of bacteria (Ecoli) that lives in your intestines. Each one benefits from the other! The bacteria gets a plentiful food supply from you, and in return you get vitamins that the bacteria produce.

Type of relationship Species harmed Species benefits Species neutral Commensalism Parasitism Mutualism = 1 species

Trophic Levels Each link in a food chain is known as a trophic level. Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem.

Trophic Levels Energy Flow: Energy is transferred upwards in a food chain, but it decreases with each transfer. The top consumer receives the least amount of energy. Sunlight – the original source of energy in your food

Trophic Levels Producers- Autotrophs Primary consumers- Herbivores Secondary consumers- small carnivores Tertiary consumers- top carnivores ENERGYENERGY

Trophic Levels Food chain- simple model that shows how matter and energy move through an ecosystem

Trophic Levels Food web- shows all possible feeding relationships in a community at each trophic level Represents a network of interconnected food chains

Food chainFood web (just 1 path of energy) (all possible energy paths)

Related Videos: Energy Pyramid – grade3_nl.htmlhttp:// grade3_nl.html Symbiosis (Cowbird) – YNohttp:// YNo