Transcript 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 • • • • • • 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