Principles of Ecology Unit 2 Chapter 2

What is ecology?  Ecology: study of interactions that take place between organisms and their environment

Biosphere  the portion of the Earth that supports living things  Ex: ocean, forest, atmosphere.

Abiotic vs. Biotic factors  Abiotic = nonliving parts of the environment  Ex: light, air, temperature, soil  Biotic = living parts of the environment  Ex: bacteria, protist, fungus, plant, animal

Levels of organization from smallest to largest  Individual  Population  Community  Ecosystem

Individual  made of cells, uses energy, reproduces, responds, grows, and develops

Population  group of organisms all of the same species, which interbreed and live in the same area at the same time

Community  interacting populations in a certain area at a certain time

Ecosystem  interacting communities and abiotic factors

Habitat vs. Niche  Habitat: place where organism lives  Niche: role or position a species has in its environment

Habitats are capable of changing. What can lead to changes in habitats?

Symbiosis: interactions between two species  Mutualism: both benefits  Commensalism: one benefits, the other unaffected  Parasitism: one benefits, one is harmed

Mutualism Clownfish is protected, while providing a lure for the anemone. Some say that this relationship can be commensalistic.

Commensalism Volcano sponge using the crinoid sponge as a “lift” for increased filtration but the crinoid sponge is unaffected.

Parasitism Head lice

How organisms obtain energy  Autotroph (producer): photosynthetic or chemosynthetic, makes own food  Heterotroph (consumer): “eat” other organisms, cannot make own food  Decomposer: breaks down dead or decaying organisms, recycles matter

Autotroph

Heterotrophs - scavengers  Scavengers: feed off of dead or decaying living things but do not recycle matter back into the ecosystem

Heterotrophs - herbivores  consume only vegetative matter  mostly primary consumers.

Heterotrophs - carnivores  obtain energy from eating other consumers  Secondary and tertiary consumers

Decomposers Typical examples: fungus and bacteria

Food chain  shows how matter and energy move through an ecosystem (one route) berries → mice → black bear

Food web  shows interactions between organisms (all possible routes)

Energy pyramid  Shows how much energy is available at each trophic (energy) level Pyramid of Energy Heat 0.1% Consumers 1% Consumers 10% Consumers Parasites, scavengers, and decomposers feed at each level.

Autotrophs First-order heterotrophs Third-order heterotrophs Second-order heterotrophs Decomposers

Four cycles in nature  Water cycle  Carbon cycle  Nitrogen cycle  Phosphorus cycle

Water cycle

Carbon cycle

Nitrogen cycle Nitrogen cycle

Phosphorus cycle