Primary production

Chapter 55: Ecosystems Ecosystems Ecosystem = sum of all the organisms living within its boundaries (biotic community) + abiotic factors with which they interact Involves two unique processes: Energy flow Chemical cycling Overview of energy & nutrient dynamics Energy Flow in an Ecosystem Energy cannot be recycled ? must be constantly supplied to an ecosystem (mostly by SUN) The autotrophs (?self feeders?) are the primary producers, and are usually photosynthetic (plants or algae). They use light energy to synthesize sugars and other organic compounds. Heterotrophs (?other feeders?) ? can?t make own food Heterotrophs are at trophic levels above the primary producers and depend on their photosynthetic output.