Ecology

2a- Ecology & Living Relationships

Principles of Ecology• Ecology – study of

relationships between living and nonliving parts of the world

• Ernst Haeckel (1866) – first to use the word to name the study of how organisms fit into their environment

Interdependence• All organisms interact with…

1. The other organisms around them2. The nonliving parts of their environment

• Survival depends on these interactions.

Interdependence

White-tailed deer Acorns

Deer mouse

Humans

Deer tick

Parts of the Environment

• Abiotic factors – non-living parts of an organism’s environment– Air currents, temperature,

moisture, light, soil

• Biotic factors – all the living things that inhabit the environment

Ecological Levels of Organization

Organism

Population

Community

Ecosystem

Biosphere

Biome

Niche vs. Habitat vs. Ecosystem

• Ecosystem – all the organisms in a given area and the abiotic factors that affect them

• Habitat – the place an organism lives out its life

• Niche – role and position a species has in its environment– Includes all biotic and abiotic interactions as an organism

meets its needs for survival– If two species are competing for the same niche, one will

most likely drive the other out and take control of the niche.

Niche vs. Habitat vs. Ecosystem

An egret lives around Jones Pond which is part of the Smith River Estuary. The egret and its mate eat fish, frogs, salamanders, snakes, crayfish, mice, aquatic insects, crickets, grasshoppers, and a variety of other insects in Jones Pond and build a nest in a tree along side the pond.

• What is the egret’s habitat?• What is the egret’s niche?• What is the egret’s ecosystem?

Organism Interactions: Predation• The number of

predators affects the prey population–More predators,

more risk to prey• The number of prey

affects the predator population–More prey, more

food for predators

Organism Interactions: Competition

• Competition – Organisms within a population must compete for resources– When populations grow, resources are in higher demand– If demand is greater than supply……population must

decrease• Fight and kill each other• Reproduce less

Relationships

• All living things form relationships with other living things

• Symbiotic Relationship – a relationship between organisms of two different species that live together in direct contact

Commensalism

• One organism benefits – The other is not affected– Examples:• Spanish moss on a tree• Barnacles on a whale• Burdock seeds on a passing animal

Mutualism• Both organisms benefit– Acacia tree and ants – tree provides food for the ants and

the ants protect the tree from animals that would eat the leaves

– Lichens: algae and fungus living together. Algae provides food (photosynthesis) and the fungus provides protection and attaches the lichen to the rock or wood where it lives.

- Bacteria living in human intestines: break down nutrients and have a safe environment

Parasitism• One organism benefits,

the other is harmed– Some live within the host

• Tapeworms• Heartworms• Bacteria

– Some feed on the external surface of the host• Ticks• Fleas• Mistletoe

– Most do not kill their host (at least not quickly)

What is this?

• Commensalism, Mutualism, or Parasitism?

Tube Worms and Hydrothermal Vents

Hydrothermal Vent Communities

• Symbiotic Relationship: Bacteria live in Tube worms.

• Worm has no digestive tract, so it relies on bacteria for nutrition.

• Bacteria oxidize hydrogen sulfide that the tube worms supplies to them.

• Both need each other to survive so what type of relationship?– Mutualism

Hydrothermal Vents are Pretty Rad.

Hydrothermal Vents

• https://www.youtube.com/watch?v=BXGF3XS-yAI