通过百度音乐客户端无限制下载
如何添加新设备？
登录 “百度音乐” 移动客户端，即可添加设备，刷新页面就可以看到新设备。
收取短信不会扣除你的话费，下载歌曲需要你支付相应的无线上网费用
百度音乐客户端听歌，随时随地
感谢您使用手机百度音乐
下载会在几秒内自动开始，如浏览器长时间没有响应，请点击
您还可以通过以下方法下载百度音乐手机版
微信扫一扫精选音乐每日推送!RELATED ECOLOGY PROGRAMS
& Functions and Values
Functions and Values of Wetlands
[This information is excerpted from Chapter 2 of &&.& Go to the
for Links to More Information.]
Wetlands perform a dazzling array of ecological functions that
we have only recently begun to appreciate. A century ago the president of the
American Health Association promoted the idea of a national campaign to
eliminate wetlands. Today, scientists recognize the environmental benefits that
wetlands provide, and they are now alerting us to the importance of preserving
rather than eliminating our wetland resources. Your wetland is likely performing
vital ecological functions that were barely recognized a few short years ago.
Even now our understanding of the complexities of wetland
ecosystems is still developing, and it seems the more we learn, the more
valuable wetlands become. Wetland ecologists have already documented the
following environmental benefits of wetlands: water purification, flood
protection, shoreline stabilization, groundwater recharge, and streamflow
maintenance. Wetlands also provide habitat for fish and wildlife,
including endangered species. Not all wetlands provide all of these benefits,
and how your particular wetland works depends on its location and its type. What
follows is a simple summary of how wetlands perform their complicated functions,
along with a brief explanation of how these functions support humans and other
Water Purification
Wetlands protect water quality by trapping sediments and
retaining excess nutrients and other pollutants such as heavy metals. These
functions are especially important when a wetland is connected to groundwater or
surface water sources (such as rivers and lakes) that are in turn used by humans
for drinking, swimming, fishing, or other activities. These same functions are
also critical for the fish and other wildlife that inhabit these waters.
Sediments, nutrients, and toxic chemicals enter wetlands
primarily by way of &runoff,& a term used to describe the rain and stormwater
that travels over land surfaces on its way to receiving waters. In urban areas,
runoff washes over buildings and streets in industrial, commercial, and
residential areas where it picks up pollutants and carries them to receiving
waters, such as Puget Sound. In rural areas, agricultural and forest practices can affect runoff.
Where the runoff drains a freshly-plowed field or clear-cut area, it may carry
too much sediment. Runoff may carry pesticides and fertilizers if these have
been applied to the land.
Sediments, which are particles of soil, settle into the gravel
of streambeds and disrupt or prevent fish from spawning, and can smother fish
eggs. Other pollutants -- notably heavy metals -- are often attached to
sediments and present the potential for further water contamination. Wetlands
remove these pollutants by trapping the sediments and holding them. The slow
velocity of water in wetlands allows the sediments to settle to the bottom where
wetland plants hold the accumulated sediments in place.
Runoff waters often carry nutrients that can cause water quality
problems. An example of such an occurrence is an &algae bloom.& Besides the
aesthetic problems associated with algae blooms (a green, smelly slime) they
result in low levels of oxygen in the water. This oxygen depletion can result in
the death of fish and other aquatic life. Some algae release toxins that can
kill pets and livestock when bloom conditions occur. Wetlands protect surface
waters from the problems of nutrient overload by removing the excess nutrients,
some of which are taken up and used by wetland plants, and some of which are
converted to less harmful chemical forms in the soil.
Toxic chemicals reach surface waters in the same way as
nutrients, and can cause disease, death, or other problems upon exposure to
plants and animals (including humans). In a function similar to nutrient
removal, wetlands trap and bury these chemicals or may even convert some of them
to less harmful forms. Scientists are continuing to study what happens to toxic
chemicals when they enter wetlands, and they warn us that even if the toxins are
buried, they are still potentially dangerous. Disruptions of the wetland soils
could release the toxins back into the aquatic environment.
Flood Protection
Almost any wetland can provide some measure of flood protection
by holding the excess runoff after a storm, and then releasing it slowly. The
size, shape, location, and soil type of a wetland determine its capacity to
reduce local and downstream flooding. While wetlands cannot prevent flooding,
they do lower flood peaks by temporarily holding water and by slowing the
water's velocity. Wetland soil acts as a sponge, holding much more water than
other soil types. Even isolated wetlands can reduce local flooding -- if the
wetlands were not there to hold stormwater runoff, backyards and basements might
end up under water.
Shoreline Stabilization
Wetlands that occur along the shoreline of lakes or along the
banks of rivers and streams help protect the shoreline soils from the erosive
forces of waves and currents. The wetland plants act as a buffer zone by
dissipating the water's energy and providing stability by binding the soils with
their extensive root systems.
Groundwater Recharge and Streamflow Maintenance
Aquifers and groundwater are &recharged,& that is, replenished
with water by precipitation that seeps into the ground and by surface waters.
Those wetlands connected to groundwater systems or aquifers are
important areas for groundwater exchange. They retain water and so provide time
for infiltration to occur. Groundwater, in turn, provides water for drinking,
irrigation, and maintenance of streamflow and lake and reservoir levels. During
periods of low streamflow (or low lake water levels), the slow discharge of
groundwater often helps maintain minimum water levels. In addition, wetlands
located along streams, lakes, and reservoirs may release stored water directly
into these systems, thus also contributing to their maintenance. Wetlands' many
intricate connections with groundwater, streamflow, and lake and reservoir water
levels make them essential in the proper functioning of the hydrologic cycle.
Fish and Wildlife Habitat
Many species of birds, fish, mammals, reptiles, and amphibians
rely on wetland habitat for breeding, foraging, and cover. The special wetland
conditions provide unique habitat for species that cannot survive elsewhere.
Migratory birds depend on wetlands, and many endangered and threatened animal
species require wetlands during part of their life cycle. The incredibly high
rate of wetlands loss has contributed to their demise.
Wetland plants and small animals -- especially insects -- are
essential links at the lowest levels of the food chain. A wetlands environment
supports these plants and animals, which in turn support the larger animals that
feed on them. While an otter or a trout may be a more attractive species to
protect than some anonymous insect or plant, the latter are no less important in
the overall scheme. If we diminish the lowest levels of the food chain, the
higher levels will suffer as well.
Economic Benefits
The economic benefits associated with these environmental values
of wetlands also can be substantial. If, for example, a community had to build
flood control or water treatment systems to replace those functions provided by
wetlands, the costs could far outweigh the land purchase price of preserving the
natural wetland systems. Similarly, when wetlands lose their value as fish
habitat, this value is difficult to replace, and the consequent losses to the
recreational and commercial fishing industries can be significant. There are as
yet no precise formulas that we can use to determine the accurate dollar value
per acre of wetland, but the more we learn about wetlands, the higher that value
Other Benefits
Some of the values associated with your wetland will be yours and
yours alone. No one else can really say what the open space means to you and your
family. How your wetland affects your quality of life, and how you value it for
its aesthetic contributions are personal matters. You or members of your family
may also get recreational benefits from your wetland -- nature
photography or birding or simply quiet time in a peaceful place.
The Limits of Wetlands
As amazing as wetlands are, and for all their ecological
contributions, they do have their limits. A partially filled or otherwise
damaged wetland is one that only partially meets its potential for flood
control, shoreline stabilization, or groundwater recharge. A badly degraded
wetland can lose its capacity to remove excess sediments, nutrients, and other
pollutants, and can lose its habitat value for fish and wildlife. Wetlands may
have tremendous capacities to provide environmental benefits, but they are not
indestructible. If we want wetlands to continue to perform their ecological
functions, then we have to do our part to protect them.
Links to More Information
U.S. Environmental Protection Agency's
Chapter 2 of
presents information on wetlands in Washington and how they function.&
Section 2.3, Introduction and Background on Wetland Functions, describes the
evolution of our understanding of wetland functions over the last few
decades. It also defines the term wetland functions. The difference between
functions and values is also explained.
were designed to
differentiate between wetlands in western and eastern Washington.& They
categorize wetlands into four categories based on their sensitivity to
disturbance, their rarity, our ability to replace them, and the functions
they provide.
are a collection of assessments
that provide a score for the degree to which several functions (up to 15)
are performed by a wetland. These methods are currently not being used,
however the documents are provided for historical reference to those wishing
to explore the scientific basis for the
, which is the current tool for gathering general information on
functions provided by wetlands.
Copyright & Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.htm& Loading... Please wait...
Camouflage Bikinis, Swimsuits, Bedding & Bath Store Online! Lowest Prices! We Stock!
Love Browning, Huntress Brand, &How About Mossy Oak, Realtree and Buckmark?
offers great prices on all the brand names that you love! So Why Choose Us? Simple! We stock! We are one of the largest stocking dealers for Camo Brand Names and in items such as shirts, swimwear, bikinis, sunglasses, merchandise for women and literally hundreds more items. What is best selling right now! Ladies love pink! Anything that is pink camo! Men love anything from the tumbler and mugs to the shirts with brand name hunting logos - Buck and Doe Apparel and Shirts!
Featured Products
$27.95 $20.95
$39.95 $27.95
$14.95 $12.95
$22.95 $15.95
$39.95 $27.95
$22.95 $18.95
$39.95 $34.95
$27.95 $17.95
$27.95 $17.95
$59.95 $36.95
$26.95 $16.95
$79.95 $39.95
New Products
$41.95 $29.95
$41.95 $29.95
$29.95 $19.95
$45.95 $32.95
$15.95 $11.95
$33.95 $19.95
$39.95 $29.95
$39.95 $29.95
$29.00 $21.95
$24.95 $19.95
$43.95 $31.95
$43.95 $26.95
$39.95 $28.95
$32.95 $21.95
$25.95 $15.95
$25.95 $15.95
$25.95 $15.95
$25.95 $15.95
$44.95 $34.95
$15.95 $11.95
$20.95 $15.95
$20.95 $15.95
<&offers high quality and great prices on so many different items from Camo For Women, Camouflage bedding to bikinis and swimsuits. We also offer&other types of bedding such as Zebra, Leopard, Cheetah, Safari,&Giraffe as well as the sheets, pillow cases, shower curtains etc. We are one of the leading Confederate merchandise suppliers online. But we don't stop there. Check out our top selling&Browning Items like Belly Rings, T&Shirts, Jewelry, Purses and Handbags, curbic zirconia& jewelry, merchandise&by top brand names like Huntress,&Budweiser, Jack Daniels, Browning, Mossy Oak, RealTree, Bone Collector and much more! We stock a ton of pink items!
How about a Browning Belly Button Ring, Pendants, Bracelets&or Earrings? Ladies love the pink Browning, Mossy Oak, Bone Collector&and Realtree&while the kids love the sheets and pillow cases, shower curtains, towels&from all the major hunting manufacturers.
EASY! When you order from us know that we pride as ourselves in inventorying a lot of our items as a dealer. This means that we stock many of our items. The results is that we try to ship faster to you!
We sell the many of the Major Brands at great prices for brand name merchandise and items! Products for the worst camo addicts! Especially&if you are a girl! Need a country girl treatment - we have a lot of choices.
What's New Here?
Need a new fix or fashion treatment? We have it! We are in the process of adding over many Brand name items that include Browning and Realtree&items including clothing and apparel items, necklaces and jewelry, gifts for her and great gift ideas for him as well including great items for the car or trucks! How about a pink "break up" steering wheel cover? Or maybe a&key chain!
That's not all! We have many of the new lingerie and lounge&wear&collection form Mossy Oak and the Realtree Purses. That's right - the handbags and they will be at at great prices.
If you can't find the items that you are looking for them simply use the search function at the top right corner. If you still cannot find it then contact us by phone or email!
What About Sales Or Coupons?
We take great pride in two main things. One -&is&having a great price on good quality items - these are&usually at least 10% off retail and sometimes as much as 45% off with sales and coupons that are offered during the year! The&2nd is that we stock or inventory many of the items that we sell. Always check back
for coupons and discounts!
$79.95 $39.95
$39.00 $31.95
$29.95 $20.95
$59.95 $42.95
$20.95 $16.95
$41.95 $29.95
$41.95 $29.95
$29.95 $19.95
$45.95 $32.95
$15.95 $11.95
$79.95 $39.95
$49.95 $29.95
$47.95 $26.95
$14.95 $11.95
$79.95 $39.95
powered by收藏到： &
(提示：顶到域名世界首页，分享给更多网友)&&
欢迎您就本域名知识点留言评论!
您的姓名：
* 可选项，留空即为匿名发表
评论内容：
剩余字数：& * 按 Ctrl + Enter 直接发送.
域名世界提醒您:评论只需提交一次,请耐心等候,审核后方可显示.
精彩域名知识
域名世界推荐