A major environmental restoration effort is under way that will affect
the Everglades and its neighboring ecosystems in southern Florida. Ec
osystem and population-level modeling is being used to help in the pla
nning and evaluation of this restoration. The specific objective of on
e of these modeling approaches, the Across Trophic Level System Simula
tion (ATLSS), is to predict the responses of a suite of higher trophic
level species to several proposed alterations in Everglades hydrology
. These include several species of wading birds, the snail kite, Cape
Sable seaside sparrow, Florida panther, white-tailed deer, American al
ligator and American crocodile. ATLSS is an ecosystem landscape-modeli
ng approach and uses Geographic Information System (GIS) vegetation da
ta and existing hydrology models for South Florida to provide the basi
c landscape for these species. A method of pseudotopography provides e
stimates of water depths through time at 28 x 28-m resolution across t
he landscape of southern Florida. Hydrologic model output drives model
s of habitat and prey availability for the higher trophic level specie
s. Spatially explicit, individual-based computer models simulate these
species. ATLSS simulations can compare the landscape dynamic spatial
pattern of the species resulting from different proposed water managem
ent strategies. Here we compare the predicted effects of one possible
change in water management in South Florida with the base case of no c
hange. Preliminary model results predict substantial differences betwe
en these alternatives in some biotic spatial patterns.