Реферат на тему Minnesota Wetland Restoration Essay Research Paper Minnesota
Работа добавлена на сайт bukvasha.net: 2015-06-14Поможем написать учебную работу
Если у вас возникли сложности с курсовой, контрольной, дипломной, рефератом, отчетом по практике, научно-исследовательской и любой другой работой - мы готовы помочь.
Minnesota Wetland Restoration Essay, Research Paper
Minnesota Wetland Restoration
“.. and from the swamp came the SWAMPTHING! The ugliest, scariest and
fowl smelling creature you could ever imagine.” This is how many wetlands are
perceived: as dank, smell places and breeding grounds for diseases. But that is
untrue. Wetlands are a vital and very important part of our environment. In the past
10 years over 10 million acres of wetlands have been destroyed, having a negative
impact on lakes and rivers and other aspects of the ecosystem. By restoring
wetlands we can begin the process of patching the hole in the ecosystem made by
the absence of wetlands.
“Wetland” is a general term used to describe the major types of wetlands.
Wetlands are areas of land that are covered by water for part of the day, or year.
There are four types of wetlands; fens, bogs, swamps and marshes. Bogs are “old”
wetlands where drainage and water circulation has become poor. Swamps are
wetlands that have trees as predominate vegetation. Fens are similar to bogs but
are found mostly in Canada. Fens are wetlands with the predominate vegetation
being grasses. (Types of Wetlands) Marshes by far are the most productive of all
the types of wetlands. They have lush vegetation and abundant wildlife. Even
though there are many different types of wetlands, not everyone agrees on what
exactly defines a wetland.
In 1991 the government redefined and toughened the definition of a
wetland. They said the following about what wetlands must be in order to be called
a wetland.
“Must have 21 days of consecutive saturation at the surface or 15
consecutive days of standing water, during agricultural growing
season. Must have the presence of water or saturated soils and the
presence of certain vegetation that adapts mostly to wet, lowland
environments. Doesn’t allow leaf and tree trunk, reduces the importance
of silt and surface marks, drift lines, pond sediment deposits that are prime
indicators under current wetland conditions.” (Kanamine, 10A)
Wetlands are area’s of land covered by water that support a great diversity of
life including plants and animals. They are usually found near lakes or rivers or
other bodies of water. Sometime the wetland is actually an area of the body of
water but only around the perimeter of the body of water.
For thousands of years wetlands were perceived as bad things. They were
thought to be breeding grounds for mosquitoes and diseases. They were thought of
as big bodies of mucky, dirty water that smelled bad.
Because of these beliefs, back in the 1860’s many wetlands were filled in to
make more land available for housing, roads and business areas. Plus, the people in
1890’s thought that they were reducing the spread of diseases that were thought to
be born in the wetland areas.
By the 1890’s thousands of acres of Minnesota wetlands had been filled in,
by using wells and clay tiles. The wells would be dug a few kilometers away from
the wet area so that the water would be drained from the wetland. They also put
tiles into the wetland to move the sitting water away from the depression in the
land, and into wells, streams and lakes. (Rebuffoni, Restoring MN B1) Slowly inch
by inch the water receded and drained away, taking some of Minnesota’s 15
million acres of wetlands with it. That’s about 25% of Minnesota’s land area. (
Rebuffoni, Restoring MN B1 )
Well it is now a century later and our idea’s about wetlands have changed.
We now are trying to reduce the destruction of wetlands and trying to restore them
to our environment. We are restoring wetlands because they are such a vital part of
our ecosystem. Wetlands are wild and beautiful things. They are home for
thousands of organisms. Wetlands are the “kidney’s of our planet.” (Williams, 42)
The shift of thought from destroying wetlands to restoring them is due to a
report written by Paul Adams that was published in 1983. In his report Mr. Adams
“came up with a way of evaluation the function a wetland performs through the
assessment of physical attributes.”(Hollis and Bedding 1)
So exactly what good is a wetland and why do we want to restore them?
“Wetlands are an important part of the ecosystem.”( Rebuffoni, DNR Picks 3 B3)
Wetlands filter sediments that come through with the surge of rainwater down to
lakes and rivers. Wetlands filter excess Phosphorus out of the water. This is
extremely helpful to the lakes and rivers near the wetlands. Excess Phosphorus in
the water causes excess growth of algee and weeds.(Rebuffoni, Minneapolis marsh
B3 ) Excess amounts of plantlife in a marine ecosystem can be extremely harmful
because they use up most of the oxygen in the water area, causing the lake or river
to become eutrophic.
Wetlands don’t only do their work on the surface water. Wetlands also help
to clean and filter the underground water.(1 million wetlands acres destroyed from
85-95 ) Cleaner underground water means less polluted soil and cleaner lakes and
rivers, which are usually feed by underground sources.
Another underground niche that wetlands fill, is they are erosion
controllers. Erosion is caused by the water picking up sediments and carrying them
away. If a river or stream runs through a wetland, all the vegetation growing in the
wetland slows down the flow of the water and thus slows picking up of sediments.
Wetlands also help control flooding. Wetlands can act as temporary hold
tanks for excess water, that would have otherwise entered the lake or river. While
providing a holding area for rain they are also doing much more at the same time.
When there is a drought a wetland slowly releases water into lakes and river to
counter balance the effect of the lack of water. (WETLANDS) Wetlands reduce
the amount of pollutants entering the lakes and rivers. Grass and leaves settle out
in the wetland instead of in the lake or river, making a nutrient rich area that is
home to many animals.
“Wetlands provide a habitat for many different varieties of birds, mammals.
crustaccea, fish, reptiles, insects, plants and amphibians.” (What purpose do
Wetlands serve?) Wetlands are the spawning grounds for many breeds of fish.
Without wetlands the number of fish would greatly decrease because of the
absence of their spawning area.
Destroying wetlands, breaks the balance in the ecosystem. Without the
wetlands, lakes become so nutrient rich that there isn’t enough oxygen for
organism to survive. Underground water sources become dirty and polluted as do
the lakes and rivers around it. Lakes and rivers and even residential ares flood.
Wetlands are a very important part of our environment and we need to stop
destroying wetlands and start restoring them. Michale Van Valkenburgh said ” Do
you want these lakes to be dead, with no fish in them and not fit for swimming, or
do you want to invest some of your resources and keep the property value high?” In
order for our lakes and river to be clean and healthy we need to start restoring
wetlands.
Restoring wetlands can be inexpensive, fast and easy. Or it can be hard,
expensive and slow.(Rebuffoni, Sierra Club 3B) It costs the Wildlife Service three
hundred and fifty to restore one acre of wetland. That is the average cost for
restoring a wetland area, but it all depends on the size of the wetland, where the
wetland is and the degree of destruction. (”Restoring MN wetlands.”)
Even though it would cost millions of dollars to restore thousands of acres
of wetlands to Minnesota, it would cost a lot less than the cost of all the damage
done in the floods of 1997.(Rebuffoni, Sierra Club 3B)
Wetland restoration takes careful planning and a lot of hard work. To
receive maximum benefit from each wetland area restored, the potential wetland
region must be carefully surveyed. Workers then must determine the best place to
restore the wetland to. The land can not be too high or too low. It can not be in an
area that is too dry or nutrient poor. The restored wetlands must be placed
strategically to receive maximum benefit of the wetland.(Rebuffoni, Sierra Club
3B)
Wetland restoration is happening all over the United States, throughout
Minnesota and right here in the Twin Cities. Last year restoring wetland “strips”
(small areas of wetlands) around Minneapolis lakes was brought up by the Park
Board of Minneapolis. They decided to start restoring wetlands to over seven
thousand acres of Minneapolis and suburban land. The wetland “strips” will not be
like the standard cattail marshes found across Minnesota, but of much lower
vegetation. The “strips” will be planted with plants that can survive in both wet
and dry habitats.(Brant, A14) These strips would be along the shores of Calhoun,
Cedar, Harriet and Isles lakes in Minneapolis and a few other lakes in the suburbs.
These wetlands would act as filters to the Minneapolis chain of lakes.
Keeping out pollutants, filtering sediments and collecting Phosphorus from storm
runoff and snow meltoff. (Rebuffoni, Minneapolis Marsh B3) The “strips” will not
be big enough to handle all the runoff from storms and melting snow, but they will
filter the first gush of the dirtiest and most polluted water that comes through.
The first lake to have the wetland “strips” put in will be Lake Harriet,
located in Southwest Minneapolis. Right now the runoff from storms and melting
snow go straight into the lake from pipes that bring dirty water directly to the lake
from the sewer. Paths in the grass near the shoreline made by joggers and walkers
have started to erode the shoreline, and the grassy area around the banks is used
for multi purposes. No matter what happens on this grassy area the runoff from it
goes straight in to the lake.
With the proposed wetland “strips” the scene around Lake Harriet will have
a very different look. Instead of a multipurpose grassy area there will be a wetland
“strip”. The pipe that use to go directly into the lake will be rerouted into the
wetland “strip”. The paths for the walkers, joggers and bikers will be move far
away from the shoreline. Low, green, wet and full of wildlife it will be a home to
many types of animals and act as filter for the lake.
“With the new wetland “strips” the phosphorus entering the lake may be
reduced by up to 50%.” (Rebuffoni, Minneapolis Marsh B3) Without all the excess
Phosphorus entering the lake the amount of lakes weed and other plant life will
decrease, making a less eutrophic environment. This is not the only positive effect
of the proposed wetland “strips”. “By combining wetland restoration and other
water catching ideas we can reduce flood levels by 40%”(Rebuffoni, Sierra Club
B3)
All around the United States individual states are working to restore their
own lost wetlands. In San Francisco the Audubon Society successfully restored a
tidal marsh along the edge of the bay. In Greensboro, North Carolina there is a
group that works to restore healthy habitats along the city’s drainage streams. But
the United States are not the only country that are restoring wetlands.
“Other countries are following suit. In 1992, Scandinavian countries were
undertaking 37 projects and restoring more than 31,000 acres of wetlands.
That same year 13 other countries -Australia, Belgium, Britain, Canada, the
Czech Republic, France, Germany, Hungary, Italy, Japan, Poland, Romania,
and Senagal-all had restoration schemes under way.”(Hollis and Bedding 1)
Wetlands are important to the environment and they are a vital part of our
ecosystem. They help filter out sediments and purify our drinking water. Like
many other natural resources, we have come to realize what importance they have
after many millions of acres of wetlands have been destroyed; much too late.
Restoring wetlands is just the beginning of the process of patching up the
environment. “Natural resources cannot be managed as individual things, but as
whole complete ecosystems whose plants and animal and human components are
functionally interwined. (Rebuffoni, DNR Picks 3 B3)