Drying and rewetting of wetland soil increases survival but hinders growth and development of larval amphibians
Ward, Krista J.
AdvisorLuhring, Thomas M.
MetadataShow full item record
Seasonal patterns of drying and rewetting of wetlands lead to episodic bouts of local extirpations and subsequent recolonization of vertebrate groups such as fish and larval amphibians. Amphibians often avoid ovipositing in pools with fish because of their strongly negative effects on survival. To avoid pools with fishes, adult amphibians frequently select ephemeral wetlands. However, the effects of drying and rewetting of wetland soils on larval amphibians is unknown. Using 64 1,000 L cattle tanks to create replicate aquatic mesocosms, we investigated the effects of past drying and rewetting of wetland soil on subsequent growth rates and survivorship of larval amphibians. We hypothesized that prior drying would negatively affect growth and survival of larval amphibians and that these would be further altered by trophic treatment. Four trophic treatments were crossed with two drying treatments to simulate different outcomes of drying history and colonization by two vertebrate guilds. The four trophic structure treatments included: 1) no vertebrate control, 2) larval amphibians, 3) fish, and 4) larval amphibians and fish. The two drying treatments were: 1) non-dry, and 2) dry-rewet. Mesocosms with amphibian trophic treatments (n = 32) received 50 Lithobates blairi tadpoles. Mesocosms with fish trophic treatments (n = 32) received one Lepomis cyanellus. We collected data on larval amphibian growth rates, total emergent amphibian biomass, time/size at metamorphosis, and emergence rate (survivorship) from May 9th, 2021 to August 1st, 2021 for a total of 12 weeks. Drying and rewetting reduced larval amphibian growth rates and size at metamorphosis, increased time to metamorphosis and asynchrony of metamorphosis, but also increased survivorship. Our results provide evidence that drying and rewetting of wetlands impact early life history traits of larval amphibians with negative implications for fitness post-metamorphosis.
Thesis (M.S.)-- Wichita State University, College of Liberal Arts and Sciences, Dept. of Biological Sciences