Created wetlands managed for hydroperiod provide habitat for amphibians in Western Kentucky, USA

Abstract

Loss of wetlands worldwide has necessitated the creation of wetlands to counteract declines of fauna associated with these habitats. Ephemeral wetlands have been disproportionally lost and hydrology of ephemeral wetlands is challenging to restore. Created wetlands with water control structures may be a viable option. In Western Kentucky, we surveyed three ephemeral wetland types [managed open canopy (MOC), unmanaged open canopy (UMOC), and unmanaged closed canopy (UMCC); managed = created wetlands with water control structures] to estimate amphibian richness and occupancy among wetlands, and estimated abundance of three locally common species: Southern Leopard Frog (Lithobates sphenocephalus), Spotted Salamander (Ambystoma maculatum), and Crawfish Frog (L. areolatus). In addition, we quantified physical characteristics and water quality among wetland types. Managed Open Canopy wetlands had a greater percent of submergent vegetation than both UMCC and UMOC wetlands, shallower depth at 1.0 m from the wetted wetland edge than UMOC wetlands, and were larger than UMCC wetlands. Mean predicted amphibian species richness and occupancy was highest at larger wetlands (0.15–0.78 ha). Occupancy of three common species was not influenced by management. Estimated abundance of L. areolatus, a species of conservation concern, was higher at MOC wetlands, and conversely, A. maculatum abundance was highest at UMCC wetlands. Larger wetlands had higher estimated abundances of L. areolatus and L. sphenocephalus. Our results suggest that created, open canopy wetlands managed for hydroperiod have similar species richness to unmanaged ephemeral wetlands. Furthermore, these managed wetlands provide habitat for a species of concern in Kentucky (i.e., L. areolatus).