Safeguarding Wetlands and Their Connections within Wetlandscapes to Improve Conservation Outcomes for Threatened Amphibian Species

Abstract

Wetlands should not be considered as independent objects but as dynamically connected objects, collectively known as wetlandscapes. We developed a framework that analyzes the influences of wetland suitability and connectivity on amphibian distributions. We defined two indices: a Wetland Suitability Index describing wetland quality and a Movement Permeability Index characterizing wetland connectivity for amphibian population dynamics. These indices were calculated from raster datasets and time‐varying inundation estimates. The indices were used to define a wetlandscape and an amphibian model was used to simulate population dynamics within the wetlandscape. The framework was applied to the Nose Creek watershed, a highly modified wetlandscape in Alberta, Canada. Two amphibian species were selected with different habitat preferences: the Northern Leopard Frog that prefers wet habitats and has high mobility over land, and the Great Plains Toad that prefers terrestrial habitats and has low mobility over land. We found each amphibian species had a “preferred” wetlandscape, reflecting their life cycle traits and migration strategies which in turn were dependent on the hydrological and ecological connections within the wetlandscape. This study highlights the importance of investigating both individual wetlands and the wetlandscape and considering both wetland habitat quality and connectivity as non‐substitutable properties that act jointly, but differently, on population dynamics.

Post-emergence survival and dispersal of juvenile Jefferson salamander (Ambystoma jeffersonianum) and their unisexual dependents

“…In a long-term study of amphibian populations, Semlitsch et al (1996) reported pond drying in four of the 16 years of their study. Hydrological variation in vernal ponds has been well documented as a limiting factor in pond-breeding amphibians (Shoop, 1974;Pechmann et al, 1989;Rowe and Dunson, 1995;Semlitsch et al, 1996;Skelly, 1996;Brodman, 2009;Mullin and Klueth, 2009) highlighting the need to protect vernal pond hydrological sources and wetland connections as part of conservation efforts (Rothermel, 2004;Crawford et al, 2016;Linton et al, 2018;Zaffaroni et al, 2019). In addition, further research is needed to understand the potential population impacts of changes in vernal pond hydroperiod due to climate change (Linton et al, 2018).…”

A framework to identify priority wetland habitats and movement corridors for urban amphibian conservation

“…Zamberletti et al (2018) studied the degree of wetland connectivity and found management actions (protection and restoration) for a specific wetland should depend on its location within the broader landscape, highlighting the importance of conservation action focused on wetland networks and not isolated breeding ponds. In urban areas, where road networks and the built environment fragment habitats, options for amphibian movement are greatly reduced resulting in low functional connectivity and reduced population resilience due to isolation, increased risk of local extinction and/or inbreeding (Allen et al, 2020;Koen et al, 2014;Zaffaroni et al, 2019;Zamberletti et al, 2018).…”

Featured Collection Introduction: The Emerging Science of Aquatic System Connectivity II

“…Caruso et al (2019) used hydrodynamic modeling to facilitate restoration of connections between the Green River and floodplain wetlands for endangered fish species recovery at Ouray National Wildlife Refuge in Utah. Zaffaroni et al (2019) used geospatial analysis and remote sensing to assess wetland networks (wetlandscapes) and habitat quality to improve conservation outcomes for threatened amphibian species which rely on different wetland, stream, and upland habitats to complete their life cycle. Both wetland habitat quality and connectivity act jointly but differently on amphibian population dynamics and should both be considered when managing wetlandscapes.…”

“…Zaffaroni et al. () used geospatial analysis and remote sensing to assess wetland networks (wetlandscapes) and habitat quality to improve conservation outcomes for threatened amphibian species which rely on different wetland, stream, and upland habitats to complete their life cycle. Both wetland habitat quality and connectivity act jointly but differently on amphibian population dynamics and should both be considered when managing wetlandscapes.…”