Vernal Pool presentation by MAD Scientist Associates on Feb 21, 2009

1. Specialists in
Ecological & Wetland
Consulting
OEC 2009 Vernal Pool Workshop
www.madscientistassociates.net

2. MAD Scientist & Associates
LLC
Established in 1998
Mark A. Dilley Chris S. Dilley
Founder and Co-Owner
Co-Owner
www.madscientistassociates.net

3. MAD Scientist & Associates
LLC
Technical Staff
Mark A. Dilley, M.S., P.W.S.
Professional Wetland Scientist
•
Certified Ecologist
•
B.S. in Natural Resources, OSU
•
M.S. in Environmental Science, OSU
•
J. David Strong
Environmental Scientist
•
Kashmira Asnani, M.S.
Ecologist
•
www.madscientistassociates.net

4. Vernal Pool
Construction
Alternate Title:
Mark vs. the Pizza!!
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5. What Makes A Wetland?
3 Parameters:
May be
Hydrophytic vegetation
sparse in
Obligate wetland (OBL)
• some vernal
Facultative (FACW, FAC, FACU) pools!
•
Obligate upland (UPL)
•
Hydric soils
Low chroma
•
Mottles
•
Wetland hydrology
Inundation
•
Saturation
•
Other indicators
•

6. Wetland Hydrology
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7. Hydric Soil

8. Site Selection
“Location, Location, Location!”
•Avoid existing wetlands!
•Consider the neighbors (mosquitoes and
flooding may not be appreciated!)
•Avoid areas with livestock
•Adjacent upland habitat and nearby
wetlands are a plus (many would argue a
necessity!)
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9. Site Selection
(continued)
•Consider (and adjust for) factors that will
influence hydrologic regime (frequency and
duration of flooding), including sunlight
exposure, soil permeability, annual
precipitation and evaporation, transpiration,
and water depth.
•Be cautious with sites that have a high
water table!
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10. Topography/
Landscape Position
•Look for areas where water would naturally
collect (floodplains, valleys)
•Flat areas (<3% slope) make for
easier/less expensive pool development
•Embankment pools on hillsides are
possible
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11. Soils
•Drained hydric soils are ideal
•Silt loams, silty clay loams (fine textured
soils) are generally suited to pool construction
(permeability rates <0.2 in/hr; can check with
simple equipment)
•Drainage class of somewhat poorly drained
to poorly drained
•Liners, while not recommended, can be used
in areas that drain too rapidly ($$$)
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12. Sizing
•Gaps in forest community as small as
15’ x 15’ can suffice (tree removal is
generally discouraged)
•Vernal pools do not require a large
watershed, due to the low storage volume
•Typical sizes range from several hundred
square feet to 3 or more acres
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13. Site Preparation
•Invasive species removal
•Trash clean up
•Mark areas, trees to avoid
•Determine, clear and mark route of ingress
and egress
•Mark pool, berm, and soil disposal locations
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14. Earthwork
•Remove and stockpile topsoil (seedbank and
rooting medium)
•Excavate shallow depression (1’-2’; use laser-
guided equipment if possible; go deeper to allow for
addition of topsoil)
•If constructing a berm, dig, fill and compact core
trench before building berm (in layers) on top
•Use gentle slopes (15:1 or greater)
•Install spillway (and control structure,
if desired)
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15. Earthwork
(continued)
•Spread topsoil across wetland
•Mini-excavator and small bulldozer will
typically suffice
•Look for competent operators
TNT can make vernal pool
construction a blast!!!
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16. Planting
•Seed and mulch (include cover crop)
•Plugs = instant wetland plants!
•Container grown trees and shrubs
•For a variety of reasons, you may wish to
avoid planting woody species on berms
•Don’t forget the buffer!
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17. Accessorizing
•Add structure in the
form of logs, rocks,
leaf litter, small high
spots of soil, and
“specimen” plants
•Do not let anyone
convince you that
tires are vernal
pool accessories!
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18. Example Projects and
Lessons Learned
Heritage Park Phase II
Boyer Nature Preserve
Vernal Pool Mitigation Area
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19. Heritage Park Phase II, Westerville, OH

20. Vernal Pool
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21. Gray Treefrog
(Hyla chrysoscelis or H. versicolor)

22. On-site Mitigation Wetland #1
Soon After Construction
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23. On-site Mitigation Wetland #1
First Year - 2003
Lesson Learned: Seed banks work!!
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24. On-site Mitigation Wetland #1
First Year - 2003
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25. Spring 2004 – Amphibians
Heritage Park Mitigation Wetlands
N. LeopardToad
American Frog
(Rana pipiens)
(Bufo americanus americanus)
Lesson Learned: Build
it and they will come!
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26. Boyer Nature Preserve

27. Mitigation Opportunity
• Concerns of long-term neighbors
regarding loss of spring peepers
• Probably a loss of habitat issue
• City was advised to look for opportunities to
create vernal pools as replacement habitat
• FACT promoted local mitigation at this
preserve to off-set impacts within the local
watershed

28. Draft Master Plan

29. The Vernal Pool Site
Covered in Amur
honeysuckle
Preparation
Wetland delineation
Invasive species
removal (FACT
volunteers and
others)

30. Site
Preparation

31. Vernal Pool Excavation

32. Seeding and Planting
Lesson Learned:
Plugs are a reliable
way to jump-start
the plant
community

33. Adaptive Management
Issues
Lesson Learned:
Properly size culverts or avoid altogether

34. Three Years Later…

35. Young American Toad
No spring
peepers – yet!

36. Some satisfied vernal pool
customers!!

37. Resources
•See handout for recommended books
•MAD Scientist & Associates
www.madscientistassociates.net

38. THANK YOU!
Questions?