EcologyEcology

Marie ČernáMarie Černá

Ecology

from the Greek words: oikos – home

logos – to study

the scientific study of the interactions

between organisms and the environment

These interactions occur at a hierarchy of scales

that ecologists study, from organismal to global.

The biological hierarchy

• Organismal ecology – physiology + behavior

• Population ecology – the same species

• Community ecology – different species

• Ecosystem ecology -

• Land(sea)scape ecology – joint ecosystems

• Global ecology = biosphere

Ecosystem

• the community of organisms in an area

• the physical factors

with which those organisms interact

Ecosystem ecology emphasizes

energy flow and chemical cycling

between organisms and the environment.

Products of ecosystem processes

Resources critical to human survival + welfare

- the food we eat

- the oxygen we breathe

Energy flow and Chemical cycling

Energy cannot be recycled - external source

Energy flows through ecosystems.

Matter cycles within and through them.

Human activities now dominate most chemical cycles on Earth

• Nutrient Enrichment (agriculture: fertilizer in groundwater + surface-water → algal growth)

• Acid Precipitation (burning of fossil fuels, coal-oil-peat: nitric or sulfuric acids in rain + snow)

• Toxins in the Environment (↑ concentration in successive trophic levels of food webs)

• Greenhouse Gases + Global Warming (↑CO2)

• Depletion of Atmospheric Ozone (chlorine-containing pollutants → the penetration of UV)

LiteratureLiteratureBiology, eighth edition,

Campbell, Reece

Unit eight: Ecology

Chapter 55: Ecosystems

Pages 1222 – 1244