Ecosystems

Ecological Succession Ecological succession – changes that occur in a community over time Especially after disturbances Some species die, other species move in Does not follow the same path each time

Primary Succession Succession in an area where there are no remains (not even soil) of an older community Example: volcanic explosion Pioneer species – the first species to inhabit an area Example: lichen

Secondary Succession Succession when a community is destroyed, but not completely (soil remains) Example: forest fire Occurs faster than primary succession

Climax community Community reaches a steady state Before After

Human Activities vs. Ecosystem Deforestation – The clearing of forest for agriculture, lumber, and other uses eliminating plants = more CO₂ in air Greenhouse Effect – the natural process by which atmospheric gases trap heat Add CO2 = global warming

Human Activities vs. Ecosystem Acid Rain – the precipitation that contains nitric and/or sulfuric acids. Pollution – The addition of substances to the environment that results in a negative effect.

Invasive Species Example: 1. Burmese Python in The Everglades Invasive species - Species that does not belong in a specific area (foreign) Cause excessive damage to the new environment Lacks natural predator, so it’s population can increase a lot In turn, drastically decreases the populations of it’s prey Example: 1. Burmese Python in The Everglades 2. Lion fish

Aquatic Ecosystems 1. Photic zone – surface where the sun reaches Photosynthesis occurs Warmer water 2. Aphotic zone – the sun does not reach No photosynthesis Colder water Benthic zone – ocean or pond floor (cold, no light)