This project serves to record observations of all organisms found in Alabama, one of the most biologically diverse states in the United States. This diversity is a product of Alabama's warm, moist climate, its great geologic diversity, and its rich evolutionary past. With more than 4,533 documented species, Alabama ranks fifth among states in terms of overall species diversity, and is first among states east of the Mississippi River. The large western states of California, Texas, Arizona, and New Mexico lead the nation, and fellow southeastern states Georgia (sixth) and Florida (seventh) trail Alabama. Alabama harbors 64 types of terrestrial ecosystems, including 25 forests and woodlands, 11 wetlands, and 7 glades and prairies. The state also supports 77,000 miles of rivers and streams and several dozen marine ecosystems.