Download 39-Ecology

Ecology
Marie Černá
Ecology
oikos – home
logos – to study
the scientific study of the interactions
between organisms and the environment
from the Greek words:
These interactions occur at a hierarchy of scales
that ecologists study, from organismal to global.
The biological hierarchy
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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, coaloil-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 (chlorinecontaining pollutants → the penetration of UV)
Literature
Biology, eighth edition,
Campbell, Reece
Unit eight: Ecology
Chapter 55: Ecosystems
Pages 1222 – 1244