Landscape structure can influence demographics of spatially structured populations, particularly less vagile organisms
such as amphibians. We examined the influence of agricultural landscape structure on community composition
and relative abundance of the 4 most common amphibians in the Southern High Plains of central USA.
Amphibian populations were monitored using pitfall traps and drift fence at 16 playa wetlands 8 playas/year in
1999 and 2000. We quantified landscape structure surrounding each playa via estimating 13 spatial metrics that
indexed playa isolation and inter-playa landscape complexity. Multivariate ordination and univariate correlations
and regressions indicated that landscape structure was associated with community composition and relative
abundance for 2 of the 4 amphibians. Spadefoots Spea multiplicata, S. bombifrons generally were positively
associated with decreasing inter-playa distance and increasing inter-playa landscape complexity. Great Plains
toads Bufo cognatus and barred tiger salamanders Ambystoma tigrinum mavortium usually were negatively
associated with spadefoots but not influenced by landscape structure. Composition and relative abundance patterns
were related to amphibian body size, which can influence species vagility and perception to landscape permeability.
Spatial separation of these species in the multivariate ordination also may have been a consequence of
differential competitive ability among species. These results suggest agricultural landscape structure may influence
abundance and composition of spatially structured amphibian populations. This also is the first applied
documentation that inter-patch landscape complexity can affect intra-patch community composition of amphibians
as predicted by metapopulation theory. In the Southern High Plains, landscape complexity is positively associated
with agricultural cultivation. Agricultural cultivation increases sedimentation, decreases hydroperiod,
alters amphibian community dynamics, and negatively impacts postmetamorphic body size of amphibians in
playa wetlands. Thus, conservation efforts should focus on preserving or restoring native landscape structure,
hydroperiod, and connectivity among playas to maintain native amphibian populations and historic inter-playa
movement.