Pond Boss
Posted By: RAH Building a fen - 12/30/16 03:53 PM
I acknowledge up front that many say it cannot be done, but some are trying (http://www.cosia.ca/nikanotee-fen). A fen is a basic-pH bog-like wetland fed by groundwater, often rich in calcium and iron, with a stable water level. I have the water source feeding my small artesian pond. My next project is to use the pond overflow to feed an experimental fen-creation experiment. I have access to free wood chips so they will replace the normal peat base. The marl layer should form over time from the calcium-rich water. I am also looking into sourcing some pitcher plant seed collected from plants growing under alkaline conditions. I plan to stockpile the sandy loam topsoil, use the underlying clay to core the downstream end, and refill with wood chips, and then add wood-chip/sandy loam mix to the top. The plan is to vary the elevations to create conditions for a variety of flora and fauna. Since most say it will not be possible to create a fen, my expectations are low, while my hopes are high. Any help from experts, or hobbyists like me, are appreciated.
Posted By: Instar Re: Building a fen - 12/30/16 06:26 PM
My initial reaction is that wood chips are not a substitute for peat.
Posted By: RAH Re: Building a fen - 12/30/16 07:29 PM
What property or function do you believe peat has, in an alkaline fen, that partially composted wood chips won't fulfill?
Posted By: woodster Re: Building a fen - 12/31/16 02:11 AM
RAH do you have the correct range of PH in your well water? I have peat in my swamp and contrary to what most people think the water flows on top of the peat not through it. When digging my ponds the excavator would pull out large chunks of peat from under the water that were not saturated. Peat is compressed vegetation that decays very slowly because of the anaerobic conditions. The fact that there is little decomposition means the nutrient level is lower. Pitcher plants evolved to get nutrients from insects for this reason. I think it can be done if the water chemistry and PH are in the correct range. You can buy peat moss at most garden centers, I would try that before wood chips. I say if you have the correct water source, go for it!
Posted By: Bill D. Re: Building a fen - 12/31/16 02:36 AM
Are peat and peat moss the same thing?
Posted By: RAH Re: Building a fen - 12/31/16 11:12 AM
The water pH is 7.4-7.8 which should be right for a fen and might support alkaline adapted northern pitcher plants. The water is ground water and therefore very low nitrogen. I am hoping the submerged wood chips will behave anaerobically to remove nitrogen as they do in bioreactors (https://engineering.purdue.edu/watersheds/conservationdrainage/bioreactors.html). The project will be too large for me to be willing to purchase peat.

Sphagnum is a genus of approximately 380 accepted species of mosses, commonly known as peat moss.

Peat is an accumulation of partially decayed vegetation or organic matter that is unique to natural areas called peatlands, bogs, or mires.

https://mnfi.anr.msu.edu/communities/community.cfm?id=10667
Posted By: woodster Re: Building a fen - 12/31/16 06:28 PM
RAH how big is your project? I would suggest starting small and see what you can learn. You could also soak the wood chips in a 5 gallon bucket of your well water and see if the PH stays the same. In my mind the water is the key. Fens occur where the pristine water first meets the surface. If you have fish or plants in your pond the outflow may be very different then the inflow water chemistry. I would experiment with the well water before it goes into the pond and after.

Many hydroponic systems use materials other than soil to grow plants in. This is also a situation where the water is the key. Maybe you could test growing plants in you water first.

P.S. My swamp has the classic peat layer with marl soil underneath it. The marl soil contains high amounts of calcium carbonate with a high PH. The marl was formed by the algae Chara living in the glacial melt water. Chara which is plant like and stored it in its branches. Layers of dead Chara over the years built this layer. The peat formed much later when the climate warmed up. Many of us have Chara in our ponds today, including my ponds. This would be hard to build, however the plants themselves will grow in the correct water conditions.
Posted By: RAH Re: Building a fen - 12/31/16 07:39 PM
The artesian-well pond is newly made at about 25' in diameter and 10' deep. The current flow is like a garden hose. The new wetland will likely be 30-50' in diameter but could be more naturally shaped and a bit larger. The pond is not mature and the wetland chemistry will also likely change as it ages (as you have indicated). The "duck ponds" below this new project also have basic water, and they are at least 5 years old. They are primarily fed by springs and may form fens over hundreds or thousands of years. The duck ponds get periodic large bladderwort blooms. This project is an experiment. I am thinking about the pitcher plants now because it can take up to 5 years to get mature pitcher plants from seed. There are apparently sundews adapted to northern fens as well. My understanding is that peat can form from a variety of plant materials, and wood chips is just what I have available. I have a variety of other wetlands and will make another typical emergent-wetland this summer on a considerably larger scale. This seems like a cool project to diversify the mosaic of habitat types we have. My water is quite hard and comes from limestone geology. Water can be seen entering the pond through a rock in the center of the photo.

Posted By: RAH Re: Building a fen - 01/08/17 01:20 PM
Update on fen plan: After consulting someone who has actually created fens, my plan has changed. I plan to use septic-system BioDiffusers (from Menards) buried in a trench above the fen to introduce water such that it flows up (my idea to replace well screens used by this fellow in the past). These will be covered with a geotextile to help keep dirt out). Below the fen, I plan to make a subsurface clay-lined core trench to force the water up before leaving the fen. In the slightly sloping fen, I plan to till in composted wood chips. We have ordered seed for native northern pitcher plants and round-leaved sundews to get started, since they can take years to grow large enough for successful transplanting
Posted By: RAH Re: Building a fen - 04/15/17 08:10 PM
Dug a dead-end trench from the pond and started it filling to hopefully create a fen. I decided an open trench should work as good as buried perforated pipe. I will get more evaporation though. Water level should be about 6" below grade. No germination yet on the pitcher plant or sundew seed.
Posted By: 5444 Re: Building a fen - 04/18/17 11:18 AM
That's really a good looking artesian-well pond RAH. Good luck with your FEN project.
Posted By: RAH Re: Building a fen - 04/18/17 12:22 PM
Thank you. We got more good news yesterday. The NRCS had been out in August of 2015 to look at a wetland/pond project we wanted to build, but they did not have resources to survey and engineer it. They now say increased staff will allow them to do it. Hoping they visit soon.
I had given up on the project and planned to build a barn instead, but now this project will likely take priority.
Posted By: Zep Re: Building a fen - 04/18/17 03:15 PM
RAH I love your boulders......

I hope one day to have a "boulder pathway" out several
feet into my pond. But getting those heavy things placed
in water at the right height is no easy task.



My brother made (without EPA permission...lol) a litle boulder path out into the stream at his place in Colorado I used to love to fish from:

Posted By: RAH Re: Building a fen - 04/18/17 05:43 PM
I can tell those boulder just washed in:)
Posted By: Zep Re: Building a fen - 04/18/17 06:25 PM
Originally Posted By: RAH
I can tell those boulder just washed in:)


Posted By: RAH Re: Building a fen - 04/18/17 10:34 PM
Two hard-working young NRCS employees spent a long day in the brush and thorns surveying the proposed pond/wetland site so they can draw up a plan. Makes you regain faith in the work ethic of the next generation!
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