What is Ecology?

• Study of interactions among organisms and the environment– Reveals relationships between living

(biotic) and nonliving (abiotic) parts of the world.

Levels of Organization

Population

• A group of organisms of the same species that breed and live in the same place and time.

• May compete for scarce resources

Community

• A collection of interacting populations– ex. beech/maple forest– A change in one

population will cause changes in another

Ecosystem

• Interactions between the community (biotic factors) and the environment (abiotic factors)

• Three types– Terrestrial - forests, meadows,

desert scrub– Fresh water - ponds, lakes,

streams– Marine – salt water, oceans

Biome

• Large group of ecosystems that have the same climate and similar types of communities

• Terrestrial Examples:– Temperate Forest– Tundra– Desert– Grassland– Tropical Forest

• Aquatic Examples:– Rivers and Streams– Lakes and Ponds– Wetlands– Coral Reefs

Biosphere

• Layer of the Earth that supports life

• Spans from the high atmosphere to deep in the ocean.

Community InteractionsCommunity Interactions

Chapter 2 – Section

Relationships that shape ecosystems

Let’s review…

ABIOTIC FACTORS:Non-living parts of an ecosystem

Wind or air

Water

Sunlight

Soil or land

Temperature

How do abiotic factors affect an ecosystem?

Matter on Earth provides the ingredients for organic compounds.

6CO2 + H2O C6H12O6 + O2

Heat & water are distributed across the globe and regions are characterized as biomes.

Let’s review…

BIOTIC FACTORS:Living parts of an ecosystem

Bacteria

Protists

Fungi

Plants

Animals

How do biotic factors affect an ecosystem?

Living organisms use & transfer energy.Ex: producer herbivore omnivore carnivore decomposer

Living organisms cycle matter. I. e. Nitrogen fixation / denitrification – absorption & assimilation –

photosynthesis / respiration – evaporation & transpiration

COMMUNITY INTERACTIONS

Competition, Predation, Symbiosis

Compare Habitat & Niche

Habitat is the place.

Niche is the place, what is eaten, the lifestyle.

or

Habitat : Address :: Niche : Job

FUNDAMENTAL NICHE

The full range of physical and biological conditions in which

an organism lives and uses those conditions.

What would happen if all organisms attempted

to use same niche?Competitive exclusion (extinction), migration (one species moves), or

niche partitioning (they share)

REALIZED NICHE

A species may have to restrict its activity to avoid predators or sharing

with other species may prevent it from using a resource.

Therefore, they only use a portion of the fundamental niche, called the

realized niche.

Obtaining resources…

Competition – organisms attempt to use a resource in the same place at the same time.

*Intraspecies-within same species

*Interspecies-between different species

Obtaining resources…

Predation – one organism eats another

Symbiosis(from the Greek: syn "with”

and biosis "living“) describes close and often long-term

interactions between different biological species.

MutualismTwo or more organisms benefit from being in close

association with one another.

The clownfish (at left) benefits by having a protected home territory in the sea anemone. What does the sea anemone gain from this arrangement?

A lichen is actually a mutualistic association between a species of fungus and a species of either a algae or cyanobacteria.

CommensalismOne member derives benefit from the association, whereas for the other member, the association is neither beneficial

or harmful.

Barnacles are crustaceans that stick to the skin of a whale. The barnacle benefits by finding a habitat where nutrients are available. The barnacle does not appear to hamper or enhance the survival of the animals carrying them.

ParasitismOne organism lives at the expense of another. The

parasite benefits while the host is harmed

Mosquitoes eat blood for protein and can spread disease.

What kind of relationship?

Although termites can physically chew and ingest wood, they are incapable of chemically digesting cellulose into sugars. They rely on intestinal protists for digesting cellulose. These protists reside in the hindgut of termites and provide nutrition for both organisms.

A similar association exists between the ciliates of herbivores like cattle.

What kind of relationship?Animals pollinate flowers, spread seeds, and protect plants while the animals get food from plants

What kind of relationship?

Cleaning fish often seen around sharks feeding on parasites in the mouth and gills.

What kind of relationship?

Aphids are small, soft-bodied, near defenseless insects that feed on plant sap. Some ant species use excess plant sap for their own nutrition. Ants find a colony of aphids and milk the waste plant sap. In return the ants protect the aphids from predators and parasites.

What kind of relationship?

Hitching a ride

Cattle egrets perch atop the backs of cattle for a “bird’s eye view” of food that gets churned up from under the ground.

What kind of relationship?

Spanish moss is a plant that lives upon other plants (from Greek epi = “upon” and phyte = “plant”), which absorbs nutrients and water from the air and rainfall.

What kind of relationship?

What kind of relationship?

The cowbird lays its eggs in the nest of smaller songbirds. Cowbird chicks being larger birds end up pushing their nest mates aside during feedings. So the "foster parents” usually raise cowbird young at the expense of their own eggs or young.

What kind of relationship?

Water and nutrients needed by mistletoe for its growth and development are taken from the tree's sap

Symbiosis “living together”

• Mutualism – both species benefit

• Commensalism – one species benefits but the other is neither helped nor harmed.

• Parasitism – one species benefits while the other is harmed.

What is pictured?

What is pictured?

What is pictured?

What is pictured?

What is pictured?