Long Prairie Fen
In Illinois, United States
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The Coordinates listed will take you to a sign along the Long Prairie Trail where visitors can read a little information about an increasingly rare type of inland wetland. The fen highlighted by this sign and Earthcache is located to the Southeast of the sign. There is no container to find at this Earthcache, answers to questions must be emailed to me through my Geocaching.com profile.
This prairie fen is located along the Long Prairie Trail in Northern Boone County. When the former Chicago & Northwestern Railroad's Kenosha Division line was abandoned, Boone County Conservation District assumed management of the old roadbed and developed it as a bike trail under the Rails to Trails movement. This fen is in close proximity to the trail and presents a look into a unique area on the Prairie.
As the fen is an ecologically sensitive area, do not stray South of the trail rest area where the sign is located. Violators may be subject to fine or imprisonment. Permission was granted to me by the Boone County Conservation District to place this Earthcache in this location. The BCCD reserves the right to request that this Earthcache be disabled or archived if damage occurs to the natural area.
A fen is globally uncommon type of wetland that can be found primarily in the Midwest and Northeast regions of the United States. Fens are primarily groundwater fed and usually contain many minerals that are carried with the groundwater. The minerals present in the calcareous groundwater cause a naturally occurring alkaline soil system that supports many unique species of plant life. Fens rarely contain areas of standing water, however the ground is saturated. This makes the peat soil soft and springy when it is walked on. During periods of more than average rainfall, the amount of water in the soil will be higher but there will be little or no standing water.
In a fen such as this, plants such as Big Bluestem, White Lady's Slipper (rare), Purple-Stemmed Beggar's Tick, Shrubby Cinquefoil, and many species of sedges and rushes can typically be found. In addition, other alkaline-tolerant plants such as Grass of Parnassus and Kalm's Lobelia can be found.
In a prairie fen, the constant saturation of the ground does not allow for the proper decomposition of dead plant and animal remains. This is what forms the peat soil which is high in nutrients that sustain current plant life. It is not uncommon to find fossilized remains underground in fen areas due to the amount of time that it takes for a fen to form. A fen area such as this may be more than 10,000 years old.
Fens in Northern Illinois can take three forms: slope fen, mound fen, and lake edge fen.
A slope fen is a type that can be found perched on a hillside where soil drainage is low. This type of fen sometimes take the appearance of a patchwork of shrubs and grasses. The underlying soil is often comprised of limestone or dolomite. The ph level of these types of fen are slightly to moderately alkaline with high calcium levels present.
A mound fen consists of one or more calcareous mounds of peat that support a unique combination of plant life. Mound fens are created by the seepage of groundwater to the surface through a breach in the dense clay soil layers surrounding the fen.
A lake edge fen is characterized by the presence of a lake or pond nearby. Fens of this type are created when an exposed aquifer that supplies the nearby body of water is present. The aquifer layer is comprised of sand and gravel that allows water to easily pass through. Presence of this layer ensures that water collected from a nearby exposed area of the aquifer is supplied to the body of water. While that water passes through the aquifer layer, it aggregates the minerals needed to support the fen and its unique population of plants and wildflowers.
Disappearance of the fen
The number of fens across the US decreased in size in the period of time from about 1950 to 1970 due to drainage for farming, mining, and usage for fuel and fertilizer. The amount in which the fens decreased is estimated at 8% during those twenty years. Fens provide many important benefits to a watershed and its surrounding areas. Some of these include: preventing or reducing the risk of floods, improving water quality, and providing habitat for unique plant and animal communities.
Requirements for logging this Earthcache:
In order to log this cache as found, you must email the answers to the following questions to me.
1. Identify which type of prairie fen that you feel that this fen is.
2. As described by the informational sign located at the posted coordinates, what could happen to exposed peat in a fen during the period of a drought?
I will only respond to your email if your answer is incorrect.
Extra Credit: If you so wish, you can comply with the deprecated requirements of posting a photo of yourself and your GPSr at the site in your log. HOWEVER, please take the photo from the trail rest area and do not enter the fen itself.
(No hints available.)
Last Updated: on 11/9/2013 9:05:09 PM (UTC-08:00) Pacific Time (US & Canada) (5:05 AM GMT)
Coordinates are in the WGS84 datum