Wetland ecosystems occur on every continent, in every area of our
planet. They are sections that fall somewhere between land and
water: they are neither dry nor under water 100% of the time.
Wetlands are considered one of the most productive ecosystems on
Earth.
Wetland soils are considered hydric and typically have a rich
organic component formed by anaerobic processes. The lack of oxygen
causes bacteria to release two compounds that give the
characteristic smell to wetlands: sulfur and methane. Wetland soils
are typically darker and richer in fine sediments than the
surrounding surface soils.
Wetlands form when water is impeded from draining the land.
Wetlands can occur from glacial depression. They can form when
valleys get blocked and slow the flow of streams and rivers by
landslides or when animals impound the water way. Wetlands can also
form from changing water levels in freshwater lakes and
estuaries.
Water slowly infiltrates the ground and saturates the ground.
Slowly, the saturated soil water percolates deeper and deeper into
the bedrock and recharges the ground water. The soil and bedrock
filter the water and produces clean groundwater for us to use.
There are four major types of wetlands: marshes, swamps, bogs
and fens. Although wetlands play a vital role to the water cycle,
they are characterized by the vegetation present.
Marshes are areas with shallow water that are mostly grasslands.
Marshes can be freshwater or saltwater and the amount of water in a
marsh can change with the seasons and in the case of salt water
marshes, can also change with the tide.
Swamps are slow moving streams, rivers or isolated low areas
with more open and deeper water than marshes. Trees are the major
plant species in this area.
A bog is a fresh water wetland, usually formed in an old glacial
lake with a spongy peat base. Most of the bog’s water comes
from rain.
A fen is a fresh water peat wetland covered mostly by grasses
sedges, reeds, and wildflowers of high pH (alkaline) ground
water.
Over many years, by slowing the flow of water, sediments deposit
in the wetland and slowly fill it in. As the wetland deposits layer
of sediments and organic matter, eventually fossils form from
remains near the bottom.
Wetlands give scientists clues to the climate conditions over
centuries and longer by studying the preserved remains.
Pinecroft Lake wetland was created in the early 1950's when Twin
Lakes was created for a housing development. The area upstream from
the lake had a very level topography and an unintended wetland was
created.
Areas up stream from Pinecroft began to develop. Large areas of
trees were cleared and housing developments were created. Clearing
the forests allowed for a great deal of erosion.
Pinecroft Lake Wetland slows the water and filters sediments
before it reaches Twin Lakes. This wetland also has become a buffer
to avoid flooding in Twin Lakes.
ALL data can be collected from the shore. The boardwalk is currently closed. As you approach the boardwalk, you should notice several things
quickly:
1) the height of the high water marks as seen on the surrounding
trees and the boardwalk,
2)the color of the soil and
3)the dominant plant type.
4) based on what you observe, what kind of urban wetland is
Pinecroft Lake?
To get credit for this earthcache, send an email with those four
items.
Bonus credit (optional but always nice) goes if you post a
picture of group at the earthcache.
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