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Dirty Deeds

Mowing Wetland Vegetation

3 of 4

Published on: Jul. 13, 2011

The temperature isn’t the only thing heating up around Duck Creek this summer. The construction activity on the area is also increasing.

On Friday, July 8, the Conservation Commission approved the contract work for Units A and B. Last fall we presented the main concepts of this work (see "Units A and B Plan" link below). If you made it to the Duck Creek Office over the last nine months you may have seen the engineering plans on the wall. During the last week we’ve prepared for the beginning of the dirt work by planning for the end of construction. Between now and then, there is quite a list of dirty deeds.

Wetland plant response to flooding

Units A and B were one of the first parts of Duck Creek to drain after April’s deluge of rain and widespread flooding. Since then wetland plants like millet, smartweed and sedges have germinated in the moist soil conditions and have grown considerably. Typically, this kind of production is the goal of our summer wetland management. By shallowly flooding these wetland communities in the fall, migrating waterfowl can forage on the abundant seeds, plants and invertebrates and refuel before continuing their journey south. This year we have a slightly different purpose. However, it is still beneficial to know “what” and “how much” vegetation has been produced.

Good millet production

Wild millet (Echinocloa crusgalli), also known as barnyard grass, has a large seed head and is an important food for waterfowl. Wetland biologists can estimate millet production by measuring the seed head size and stem density. This helps in comparing years and conditions and learning how to tweak our wetland management practices over time. Last week we took 20 measurements of the millet in Unit A to get a quick snapshot of our production this season. Expectedly, the density of millet varied quite a bit as across the sampled area, but on average we had 500 pounds per acre. In locations were we had higher stem densities we came up with 700 to 1,400 pounds per acre. This is good for Duck Creek, especially since it is fairly early in the growing season. Unfortunately, we can’t use this to feed the ducks this year because of the dirt work, but it will still go to good use.

Wetland construction and soil disturbance

One of the downsides of moving a lot of dirt around is that it will remove valuable topsoil from certain locations. Research has shown that created wetlands often have lower soil organic matter than natural wetlands and therefore may not have the same plants (if any) right after restoration. At this point you might be saying, “Hold up, did you say soil organic matter…and did you also say no plants?”

Bear with me, I’ll try to show you how this all comes together without getting too technical.

Soil organic matter is made up of living, dead and decaying critters (from worms to microbes) and plants. It generally occurs within the first few inches to a foot of the soil surface and is critical to soil quality. The amount of organic matter in the soil influences soil moisture, soil infiltration, availability of nutrients, presence of microbes and invertebrates and root development. When this layer is removed, plant development and survival may be limited.

Perhaps you’ve seen the giant “salad shooters” that distribute straw along road-ways after a construction job. Or maybe you have placed straw or compost in your garden. Applying mulch and incorporating it into the soil are a couple ways to reduce erosion and improve soil moisture after heavy soil disturbance. The straw helps “jump-start” the soil by serving as a food source and substrate for microbes and worms to reclaim the site. Once you get the critters back, then other nutrients and soil conditions help plants become re-established.

Baling vegetation for plant reclamation

So where will we get the mulch? This is where all this information will come full circle.

Remember the millet we measured in Unit A?

Over the last week we have mowed, raked and baled approximately 50 acres of vegetation. We’ll save these for the end of the dirt work. At that time we’ll have one of our own big “salad shooters” redistribute the Duck Creek vegetation over the disturbed areas. The mulch will help minimize erosion along our gradually sloping levees. In the lower scoured areas we will distribute and mix the straw into the soil to increase the soil’s organic content. We will incorporate lime and fertilizer as well. These “dirty deeds” should help us improve the soil quality and “jump-start” the microbes and plant communities in Unit A. By having a quicker turnaround we can continue to provide productive habitat for waterfowl and quality hunting experiences for you and me.

Comments

On July 23rd, 2011 at 5:22pm BUB said:

Just wondering, will any of Unit A be open for goose hunting after the close of duck season. I enjoy hunting geese in late season and was wanting to know if anything was going to be available to hunt in late season. Thank you for your time.

On July 22nd, 2011 at 3:12pm frank said:

Below this comment box is Related Information.  Check out the Unit A and B Concepts link for a better idea of what we are doing. 

On July 22nd, 2011 at 3:10pm frank said:

Unit A is being totally reconfigured and combined with Unit B.  This will make better use of the fall of the land.  We won’t have to flood whole units too deep to push water uphill, which was the case in the past.  Additionally, we will have the capacity to flood the northwest corner of Unit A and the west side of Unit B, where it wasn’t possible in the past.  We are demolishing the blinds in Unit A because they are old and nasty.  We probably will put some blinds back in, but not immediately.  The hunting positions will stay approximately in the same spots, but we will be adding a few more positions because of the added flooded acres I mentioned above.  Additionally, we should have more teal hunting opportunity because we’ll have the scours flooded early on.  Thanks for the questions. Have a good weekend.

On July 22nd, 2011 at 2:56pm Duck Hunter said:

How much is unit a going to be, will it stay the same just more level or is it going to be completely different. I have heard that some positions will be taken away is this true.

On July 21st, 2011 at 8:52pm frank said:

As I mentioned, things are heating up on Duck Creek.  Last week the final paperwork was signed off on and the contractors are now on site.  The prep work has started and dust is in the air.  Hopefully, we’ll get a couple rains occasionally to keep some moisture in the dirt and progress will move swiftly.  Who knows, we could have the bulk of the dirt work done before the start of waterfowl season.  We’ll just have to see.  However, more than likely the electricity to the pumps won’t be hooked back up until next summer.

On July 21st, 2011 at 8:26pm Darin said:

Just exactly when will the dirt work begin and will it disturb the ducks during duck season if it still ongoing????

On July 21st, 2011 at 3:08pm frank said:

Thanks for the good question.  Unfortunately, silver carp are already in the ditches around Duck Creek.  We haven’t gotten water from the Castor River Diversion Channel for the last 2 years because of the construction at Cato.  Last fall when we let water go over our structure in Ditch 111 by Pool 1 we had several silver carp jumping out of the water just below the structure.  Silver carp are a riverine species and eat primarily plankton.  So while it isn’t ideal to have this invasive species in our waters, we don’t expect a significant impact to our recreational fishery.

On July 20th, 2011 at 6:01pm Just a local resident said:

I have had those flying carp in my boat as I run the Diversion Channel, 1 mile below Greenbriar. When you open up ditch 111 to put water in Duck Creek and Mingo. Will you not be opening these areas to a invasive species?
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