Why are wetlands important to our ecosystem?
A wetland can be areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres. Wetlands play a number of roles in the environment, principally water purification, flood control, carbon sink and shoreline stability. Some wetlands are naturally occurring, others have been created over the centuries, primarily for efficient irrigation and to ensure a regular water supply.
What makes wetlands so ecologically important is their biodiversity. Their unique and wide ranging combination of plant and animal life plays a crucial role in the balance of nature. Wetlands have a number of functions that directly impact human life, the importance of which is now being properly understood. Whereas they have previously been seen as economically unproductive pieces of land and therefore have been drained and developed; the impact of such interference is now being felt.
Wetlands are vital for human survival. They are among the world’s most productive environments; cradles of biological diversity that provide the water and productivity upon which countless species of plants and animals depend for survival.
Wetlands as flood control
Infographic courtesy of the RSPB at http://www.rspb.org.uk/forprofessionals/policy/water/flooding.aspx
We know that we have a potential flood crisis on our hands in the UK and the irony is that nature has the solution and in many cases we have created the problem! Water is our very lifeblood and managed properly we need not experience the swings of drought and flood. Yes, the climate is changing, and yes we do need to tackle that too. However, in the short to medium term we can do much to help nature restore the balance between necessary rainwater and damaging floods.
Habitats such as upland bogs and moors, woodlands, wetlands and species-rich grasslands act as giant sponges, absorbing and holding water and slowing down water run-off into rivers.
http://www.wildlifetrusts.org/tacklingflooding#Make the land
Rather than drain wetlands to build housing and then have to build in drainage ditches and watch them flood- we need to preserve our wetlands and let them do their job! We need to revise our view of the economic worth of these crucial natural reserves in terms of how much it costs us NOT having them! There have been a number of studies on this – some more impenetrable than others to understand! A report from the Department for Environment Food and Rural Affairs (Defra) is summed up in a readable way by this Guardian article http://www.theguardian.com/environment/2011/jun/02/uk-green-spaces-value
It is not just the bogs, marches, peat fens that help with flood control, but the habitats that thrive on them.
When peat becomes completely saturated and unable to absorb any more water, surface pools and peatland vegetation – including sedge meadows and some types of forest – help to slow and reduce runoff. Similarly, floodplains alongside the lower reaches of major rivers, such as the Nile, Yangtze and Danube allow heavy rainfall or spring snowmelt to spread out slowly. When the peat bogs are drained or the floodplains reduced, the risk of flash floods is increased.
Wetlands and clean water supply
You have probably seen many pictures of under developed countries and their polluted water supplies. You may well be extremely thankful that here in the UK we are able to take clean water for granted- turn on the tap and out it comes. Around the world, water treatment plants work 24/7 to ensure clean water is available to the world’s population. Nature knows how to do this without complex technology! Wetlands act as the Earth’s filters, cleaning up water in a number of ways. For example, nitrogen in water is transformed to harmless nitrogen gas, nutrients are taken up by wetland plants in the water. Wetlands remove pollutants such as phosphorous, heavy metals and toxins which are trapped in the sediments of the wetlands. In addition, nitrogen and heavy metals are incorporated into peat during its formation.
Here’s a fascinating example of the economic benefit of wetlands,
New York City found that it could avoid spending USD $3-8 billion on new waste water treatment plants by investing USD $1.5 billion in the purchase of land around the reservoirs upstate. This land purifies the water supply for free.
I shall be writing about different wetlands and sites of specific environmental interest throughout Suffolk/Norfolk in follow up posts, starting with Redgrave and South Lopham Fens, near Diss.
Please share this post to raise awareness of the importance of UK wetlands.