AMPHIBIAN BIODIVERSITY RECOVERY IN A LARGE-SCALE ECOSYSTEM RESTORATION
ROBERT BRODMAN1,2, MICHAEL PARRISH1, HEIDI KRAUS1 AND SPENCER CORTWRIGHT3
1Biology Department, Saint Joseph’s College, Rensselaer, Indiana, 47978, USA
2Corresponding author, e-mail: [email protected]
3Biology Department, Indiana University Northwest, Gary, Indiana, 46408 USA.
Abstract.— Amphibians are important components of ecosystem function and processes; however, many populations have declined due to habitat loss, fragmentation and degradation. We studied the effect of wetlands ecosystem restoration on amphibian population recovery at Kankakee Sands in northwest Indiana, USA. We also tested predictions about colonization in relation to proximity to existing nature preserves and species characteristics. Prior to restoration activities (1998), the amphibian community at Kankakee Sands consisted of fourteen populations of seven species at seven breeding sites. By 2001, this community increased to 60 populations at 26 sites; however, species richness had not increased. By 2002 the community increased to 143 populations of eight species at 38 sites, and by 2003 there were 172 populations of ten species at 44 sites. Abundance index values increased 15-fold from 1998-2003. These increases best fit the exponential growth model. Although survival through metamorphosis was substantial during wetter than average years (2002 and 2003), during other years restored wetlands dried before larvae of most species transformed. Amphibian colonization was greatest near a nature preserve with the greatest amphibian diversity. The earliest colonists included fossorial species and those species whose habitat includes wet and mesic sand prairie. However, the fossorial Tiger Salamander (Ambystoma tigrinum) was the last species to colonize Kankakee Sands.
Key Words.— amphibians; applied ecology; ecosystem restoration; prairie; savanna
Source: Herpetological Conservation and Biology 1(2):101-108