Making Meaning at Tidmarsh

Seven years post restoration, 51 people from 21 organizations assembled at Mass Audubon's Tidmarsh Wildlife Sanctuary to walk, explore, and learn how this wetland restoration has responded to the restoration intervention. The goal of the day was to learn together about the process of recovery at Tidmarsh, and collect insights that can be applied to other wetland restorations of cranberry farmland.

Stop 3: Before/After

Restoration Actions

• Remove earthen dam and water control structure
• Fill existing main channel and ditches (lateral and perimeter.
• Reconstruct 2 tributary channels.
• Roughen/uncompact bog surface.
• Create small open water feature including springs along berm; add logs for turtle basking.
• Install riffle grade control at pond outlet.

Design

Expectations

• Microtopography will create variable surface soil moisture; top of hummocks will be drier than the bottom.
• Growing platform will host a diversity of habitats and wetland plants, largely from the seed bank.
• Raising water-level will make site wetter: constructing a riffle is a cost-saving measure to raise water level.
• Shallow area at confluence will be used by a diversity of wildlife.
• Camera, microphone, and environmental sensors will allow for a diverse data set.
• Technology will be sufficiently far away from visitors that it will not attract attention except on-line.

Concerns/options

• "This is a mind bender as far as I am concerned": Alex.
• We made a conscious decision to excavate sand and create a small pond where springs emanated along the berm. (You will see a larger pond at stop 4 after lunch).
• Large 225 acre site made filling all ditches challenging; we did not do a good enough job filling ditches.
• This is a higher (drier) portion of the site; we could have created an even grade to the road (not done microtopography there).

Photo credits: Hackman, Mayton, Beattie, Watts.

Observations collected from all participants

• En route: veg very dense, some phragmites.
• Small pond is quite warm.
• Small pond: Watermeal (Wolffia) and possibly Carolina fanwort (Cabomba caroliniana), an introduced species.
• Designed to adapt to sea level rise.
• Sand was thicker in this area than in other areas.
• In some places we removed sand from down to peat. (Often in pits of microtopography).
• Confluence of tributary from Arm and from Fresh Pond tributary = open water area.
• Stream bottom sandy and firm. Will that change?
• Slow flowing stream system is at elevation 10.
• Tributary from the Arm: Temp 18°C (64.4°F); Tributary from Fresh Pond: Temp 24°C (75.2°F); Air temp 32° (89.6° F).
• Overall growing surface is drier than stops 1 & 2.
• Woolgrass is the dominant grass, with a lot of Spirea tomentosa (Steeple bush).
• Ditches very wet, soft, mucky - not well filled.
• Instrumentation records 24/7 (Brian Mayton)
• Otters but no beavers yet.

Recommendations

• Overfill ditches.

Photo credits: Ballantine, LO, LO, Watts.

Stop 4 is up next.