Ponds and geography

What is a pond?

A pond is a small area of still water. There is not much difference between a pond, a lake and a puddle. However, a lake is usually larger, may have waves on the surface and, as it is deep, no plants grow in the middle. Puddles are usually smaller than ponds and dry up quickly. A large one, however, can make a good temporary pond.

How are ponds made?

Natural ponds form when hollows in the ground fill with rain, spring or river water. They are more common in mountains and moorlands where there is much rain, although their life can be sparse as the surrounding soil has few nutrients.

In lowland areas ponds can only stay full of water where there is impervious rock or clay, an artificial lining or a naturally high water table. Many of Cornwall's best ponds occur in wetland areas with a high water table. Most ponds have been made by people (see PONDS AND HISTORY).

How people's activities have affected ponds

Since the beginning of the century Britain has lost about three quarters of its ponds! There aren't as many uses for ponds nowadays, so many of them have become neglected and grown over (see PONDS AND HISTORY). Also, some have been filled in so that the land can be used for farming or building. Pollution from traffic, fertilisers and pesticides has destroyed the wildlife in others. Thus some species of plants and animals - like amphibians and dragonflies - that depend upon ponds have declined significantly.

As well as ponds, other areas of wetland have been lost. The Cornwall Biodiversity Initiative has identified wetlands as Cornwall's most threatened habitats.

On a more positive note, pond creation - often specifically for wildlife - is becoming more and more popular on farms, nature reserves, school grounds and in gardens. It's difficult to replace the well-established ponds - and, importantly, the land habitats around them - that have been lost, but every new pond does help.

Activities

1. Looking at maps

Find local streams and rivers. Are there any ponds or lakes marked? Can you think of any ponds that are not marked on the map? Are there any that have disappeared since the map was made? Draw a map of your playground and pond if there is one.

2. "Bird's eye view"

Draw a plan of the pond.

3. Make a mini-pond

Wherever water collects, new life can spring into action! Leave a plastic bowl or basin of water outside - you could sink it into the ground - and see how long it takes for the first organisms to arrive. Look for microscopic algae and tiny rafts of gnat eggs. See if any other plants or animals take up residence in the basin with time.

4. Pond water changes

Observe and record the changes in water level in a pond - or even something like a sunken basin. Use this as a basis for discussing where the extra water comes from and what becomes of the water lost. Consider, or observe if possible, the freezing and thawing of the water. Discuss the implications of all of these things for life in the pond.

Pond Pack Introduction Why study ponds? Pond-dipping Safety for teachers Safety for kids Animal variety Moving and breathing Cycles of life Webs of life Plant life Maths English Geography History Art and design Make a pond Plant identification Animal identification Activity sheets Bug dial Where to go Acknowledgements EDUCATION NATURE SEARCH . . . . . . . . .