Terms for organisms of different trophic levels in terrestrial ecosystems

Producers - Autotrophic organisms that make their own food via photosynthesis

Consumers - Heterotrophic organisms that eat the producers

Herbivores - Animals that eat plants; primary consumers

Omnivores - Animals that eat plants or animals; can be primary or secondary consumers

Carnivores - Animals that eat other animals; secondary consumers or tertiary consumers

Decomposers - Organisms that are involved in recycling nutrients back into the ecosystem; insects, scavengers, bacteria, fungi, other microorganisms


Humans as the ultimate consumer

Earth's ecosystems cannot sustain the current levels of economic activity and material consumption

Current rates of resource harvesting & waste generation exceed natural regeneration rates


Ecological Footprint

Defined as the area of ecologically productive land and water in various classes (cropland, pastures, forests and other natural ecosystems) that would be required on a continuous basis to provide all the energy and material resources consumed, and to absorb all the wastes discharged by a population with prevailing technologies. (Wckernagel & Rees 1996 - Our Ecological Footprint)

assumes that every category of energy & material consumption + waste discharge needs a certain amount of productive and absorptive capacity of a finite are of the planet

What is Ohio's Ecological Footprint?


Ohio has a population of about 11.5 million

11.5 million X 5.1 ha (the American EF) = 58,650,000 ha

Ohio has an area of 10,717,700 ha

It's about 5 times bigger than the state!!!!




Why do I need to know this stuff? It's so depressing!

Knowing our circumstances is an invitation to change

The environment is not something "out there" -- we're part of it

The current environmental crisis is more of a behavioral and social problem than a problem with technology and development

Understanding ecological constraints can help in developing strategies for sustainable economies



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Please send your suggestions, comments, corrections, and/or questions to wolfe.205@osu.edu
Last updated January 29, 1999.