TY - JOUR
T1 - Fish population dynamics in a seasonally varying wetland
AU - DeAngelis, Donald L.
AU - Trexler, Joel C.
AU - Cosner, Chris
AU - Obaza, Adam
AU - Jopp, Fred
N1 - Funding Information:
DLD was supported by the U. S. Geological Survey and by the USGS's Greater Everglades Priority Ecosystem funding. JCT was supported by Cooperative Agreement J5284060020 between Everglades National Park and Florida International University, funding provided by the Comprehensive Ecosystem Science Initiative (CESI). CC was supported by NSF Grant DMS-0816068. Aspects of this paper are based upon work supported by the National Science Foundation under Grant No. DBI-0620409 and Grant No. DEB-9910514. FJ was supported by the U. S. Geological Survey.
PY - 2010/4/24
Y1 - 2010/4/24
N2 - Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the 'reaction-diffusion' mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction-diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first-the 'refuge mechanism'-hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the 'dynamic ideal free distribution mechanism' is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.
AB - Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the 'reaction-diffusion' mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction-diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first-the 'refuge mechanism'-hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the 'dynamic ideal free distribution mechanism' is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.
KW - Diffusion-reaction model
KW - Fish functional group
KW - Fish refugia
KW - Ideal free distribution
KW - Wetland
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U2 - 10.1016/j.ecolmodel.2009.12.021
DO - 10.1016/j.ecolmodel.2009.12.021
M3 - Article
AN - SCOPUS:77349097824
VL - 221
SP - 1131
EP - 1137
JO - Ecological Modelling
JF - Ecological Modelling
SN - 0304-3800
IS - 8
ER -