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Explore the scientific study of organism-environment interactions at various scales, from individual organisms to global ecosystems. Learn about energy flow, chemical cycling, and the impact of human activities on ecological processes.
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Ecology Marie 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 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)
Literature Biology, eighth edition, Campbell, Reece Unit eight: Ecology Chapter 55: Ecosystems Pages 1222 – 1244