Vernal Pools & Amphibians
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This document discusses vernal pools as important amphibian breeding habitat. It notes that vernal pools are seasonal forest depressions fed by surface water and groundwater. They provide habitat for many amphibian species but are disappearing. The document summarizes the habitat needs of various amphibian species that use vernal pools, including woodlands surrounding the pools, seasonal hydrology, an absence of fish, and leaf litter. It emphasizes that protecting existing vernal pool habitats and creating new habitats is important for reversing the decline of amphibian populations that rely on these ephemeral wetlands.
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Vernal Pools & Amphibians
- 1. Vernal Pools – World of Amphibians Mick Micacchion Ohio EPA, Wetland Ecology Group
- 2. Vernal Pools • Forested and Shrub depressions in a forested landscape • Isolated hydrology – primarily surface and ground water • Seasonal hydrology – ephemeral – at least late winter (Feb/March) to early summer (June/July) • Provide important amphibian breeding habitat
- 3. Amphibian Habitat Needs • Woodlands – especially important within 200m radius • Seasonal hydrology - March-June at minimum • Fish-free – bass, sunfish, pike, bullheads • Leaf litter/ Woody debris • Other breeding pools nearby
- 4. Ohio Vernal Pool Habitat Summary • Forest or shrub habitat • Forest surrounding pools • Other nearby pools • Seasonal hydrology • Surface water and/or groundwater hydrology • Fish-free • Leaf litter and woody debris • A habitat we are losing in Ohio • Complex ecosystems, not easy to replicate
- 5. Vernal Pool Habitat in Ohio • A habitat that is disappearing at alarming rates • Many species that rely on this habitat are becoming rare • Those habitats that are remaining need to be protected • Development of additional habitat is critically needed to help reverse the trend
- 6. Ohio Monitored over 200 wetlands for amphibians
- 10. Amphibian Habitat Needs Salamanders 12.6 hectares 31.0 acres 1000 meters 200 meters Wood Frogs 314.0 hectares 775.9 acres
- 14. Western Chorus Frog, Pseudacris triseriata
- 17. Northern Leopard Frog Lithobates pipiens
- 18. Northern Leopard Frog, Lithobates pipiens
- 21. Wood Frog Distribution From Davis and Menze 2000
- 22. Wood Frog Reproduction Ecology • Late winter/early spring, males advertise • Only breed for a few days each year • Communal egg laying • 800- 1200 eggs per mass • Larvae metamorphose in about 90 days • Males mature in 1 year, females in 2 years • Adults live 3 to 4 years tops
- 24. Wood Frog Egg Collection • Clear Creek Metro Park and other sites in Hocking Co. • Collected and moved 750,000 eggs • Collected by hand • Eggs iced in buckets with water and trucked • Eggs deposited same day
- 25. Repatriation Sites • 3 Metro Parks • Sites that once had wood frogs • 30,000-50,000 eggs per pool • Cluster eggs together
- 26. Success Criteria • Successful breeding – Large numbers of breeding adults in the pools – A like number of eggs, tadpoles and metamorphs • Healthy populations of wood frogs throughout the parks • Long-term viability of the populations • No human intervention required
- 35. Spotted salamander A. maculatum response to % forest coverage 1 Probability of A. maculatum occupancy Classification Tablea Predicted Ambystoma maculatum Percentage Observed 0 1 Correct Step 1 Ambystoma 0 17 3 85.0 maculatum 1 4 12 75.0 Overall Percentage 80.6 a. The cut value is .500 0.5 0 0 25 50 75 100 % Forest within 200m Slide by Deni Porej
- 44. Four-toed Salamander, Hemidactylium scutatum Photo by Jim Harding
- 45. Four-toed Salamander and eggs Photo by Mike Graziano
- 46. Identifying Potential Sites • Hydric soil areas where hydrology can be restored by minimal construction – breaking tiles – plugging ditches • Existing woodlands – In field or old field surrounded by woodlands or nearby (within 200m) – Located in existing woodlands • Restoration preferred • Creation if all other factors are good
- 47. Identifying Potential Sites • Existing populations of breeding amphibians – Close enough to migrate to new wetlands – Repatriations should only be a last gasp attempt • Extremely labor intensive • Low probability of success • Locate near existing vernal pools – Metapopulation dynamics – Breeding success
- 48. Construction Techniques MINIMIZE THE DISTURBANCE! • Keep engineering simple -break tiles/plug ditches • Move as little soil as possible • Work with existing landscape features – Use existing depressions – Work around existing mature trees • Stockpile and replace top soil, leaf litter and woody debris
- 49. Pool Construction • Keep slopes gentle - 1:15 > 50% of pool margins • Maximum depths of pools at 18-24” with occasional depths of < 36” • Develop hummocks and tussocks and work with existing features if present • Plant native vernal pool plants
- 50. Predicted “High Quality” Vernal Pool Locations