The Ecosystem and how it relates to Sustainability

Take home message:

Everything is connected to everything else.  (The trick is to discover the strength of the connections.)

Main Terms and Facts:

Ecosystem; Abiotic and biotic components

Biogeochemistry and biogeochemical cycling

Ecology - at levels of individual, population, community, ecosystem

Producers and consumers (herbivores, carnivores, detritivores)

Primary production, trophic levels, and functional groups

Redfield ratio - C:N:P:Fe (element ratios, stoichiometry)

Scientific Concepts of (a) Standing stock, (b) Mass balance, (c) Material flux rate, (d) Residence time, and (e) Positive and negative feedbacks


Main Concepts:

·        Open versus closed systems.

·        Ecosystem processes: energy transformations and biogeochemical cycles.

·        Element cycling, including residence time.

·        Food chains versus food webs.

·        Explain the principles of element ratios, mass balance, and residence time, and give examples of how these tools can be used to study environmental problems (use calculations).

·        Discuss the two main theories about how ecosystems are controlled -- bottom-up and top-down.

·        Distribution of the world’s biomes – what determines their geography?