Unit 9 Ecology UNIT 9 ECOLOGY The Principles

Unit 9 Ecology

UNIT 9 : ECOLOGY The Principles of Ecology – study of the interactions among living things and their surrounding. • Name comes from Greek word “oikos”- meaning “house”.

Levels of Organization • Organism – an individual living thing Ø example:

• Population – group of same species that lives in one area Ø example:

• Community – group of different species that live together in one area Ø example:

• Ecosystem – includes all organisms as well as the climate, soil, water, rocks, and other non-living things in a given area. Ø example:

• Biome – major regional or global community of organisms characterized by climate conditions and plant communities that thrive there. Ø example:

• Biosphere – portion of planet where life exists Ø 2 miles (↨)

Ecological research methods include observations , experimentation, and modeling • Observation – the act of carefully watching something over time. Ø May be long term or short term studies Ø Surveys are used to monitor and observe populations

• Experimentation – may perform experiments in the lab or in the field Ø lab experiments give researcher more control, but artificial setting does not reflect complex interactions that occur in nature. Ø field experiments gives more accurate picture but is more difficult because of numerous factors at work in nature.

• Modeling – use of computer or mathematical models to describe and model nature based on real data. Ø Can see how one variable affects another Ø Can create virtual ecosystem

Biotic and Abiotic Factors • An ecosystem includes both biotic and abiotic factors Ø Biotic – includes living things

Ø Abiotic – includes nonliving things such as moisture, temperature, wind, sunlight, and soil

Changing one factor in an ecosystem can affect many other factors • Biodiversity – the assortment, or variety, of living things in an ecosystem Ø amount depends on many factors Ø tropical rainforests have large biodiversity

• Keystone species – a species that has an unusually large effect on its ecosystem Ø loss of this species may cause ripple effect felt across entire ecosystem

Ø Example: beaver changes habitat for many other species by creating ponds

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

Symbiotic Relationships Commensalismone species benefits and the other is neither harmed nor helped Ex. orchids on a tree

Symbiotic Relationships Commensalismone species benefits and the other is neither harmed nor helped Ex. polar bears and cyanobacteria

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

Symbiotic Relationships Parasitism- parasite-host Ex. lampreys, leeches, fleas, ticks, tapeworm

Symbiotic Relationships Mutualismbeneficial to both species Ex. cleaning birds and cleaner shrimp

Symbiotic Relationships Mutualismbeneficial to both species Ex. lichen

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