It is a well enough known fact that the British countryside has lost, over the past half-century or so, a very considerable and worrying number of ponds. Northmoor TRust To some extent, 20th century gravel extraction has mitigated these losses in the creation of new water bodies. However, these flooded workings are generally large in size and the ecology that they support is often different from that of the traditional farm pond or flooded marl pit.

This can be for a variety of reasons, ranging from the presence or absence of predatory fish to the different ways in which water heats and cools according to its mass.

But what constitutes a pond and marks it out from any other area of water? While there is no absolute answer to this question, the National Pond Survey defines a pond as being: a body of water, of man-made or natural origin, between one meter square and two hectares, which usually holds water for at least four months of the year'.

Our pond heritage is, to a great extent, the result of man's activities - with natural ponds occurring, in many areas, much less commonly. It is also true that the recent destruction of so many ponds has been at the hand of man. So why did we dig them and why have we been filling them in?

The most obvious purpose for ponds in the countryside has, for time immemorial, been for the watering of livestock and crops. Ponds were also designed as principle providers of food with carp (or stew) ponds being a particular aspect of the medieval landscape - duck for the table being another reason for pond building.

Others were created as the consequence of various other industries such as the quarrying of stone for building, the collection of clay for pottery or the cutting of peat for fuel. In certain areas of the country ponds were also a main provider of reed, willow and osier for thatching and weaving.

Ponds were also dug in the form of moats for defensive purposes.

As industrial mechanisation began to influence how the landscape was used, stored water was used to power mill wheels for grinding and later for small-scale electricity production.

Ponds in all their forms have also served as watering holes on highways, convenient places to interrogate the local witch population and as soaking pits for woodworking.

While all this activity was taking place, naturally occurring ponds were being created all the time - from oxbow lakes to the watery depression left by a fallen tree - and these too have distinctive characteristics.

The geology, topography and soil types in any given landscape will also determine the character of those ponds that may be found there. Clay will hold water easily and the muddy waters of these will be distinctly different from the clear water that will be found in a chalk pit (where water will tend to hold only where the water table allows it to).

The biology of a pond will be as much determined by these aspects as it will be by its geographical position, its profile, whether it is in shade or not, how unpolluted the water is, if the water is fed or rises and falls with rain and sun and by any number of other factors. In short, no two ponds are the same.

Considered together though, ponds in all their shapes and forms support a vital and fascinating kaleidoscope of plants, insects and animals.

Fortunately, Oxfordshire remains reasonably well endowed with ponds with many communities still taking great pride in their village pond and with a variety of soil make-up -- from gravel to clay to chalk -- providing for a variety of pond types, natural and man-made.

Sadly, with the advent of piped water supplies and the acceleration of modern farming and industrial practices, many of our ponds have become neglected or have disappeared - it is the natural fate of all ponds to return to dry land over time and, where this is not the case, the land has often been manually recovered for some other activity.

There is some encouragement nevertheless to be had with the increasing rise in enthusiasm, of the general public for our natural heritage and in the subsequent growth in support for wildlife charities, societies and trusts. Perhaps such groups will yet prove to be the saviour of many of our aqua-specific flora and fauna communities.

Outside of the organised pursuit of habitat improvement, it is gardeners who are playing an increasingly important role in the preservation of many species, as dedicated areas of gardens have been given over to wildlife ponds and other conservational interests. Without gardeners having found space for a small area of water, the common frog might now be absent from large swathes of the country.

Frogs are of course among the star attractions of the pond, particularly among the young, and are often the prime motivation for wanting to site a pond in the garden - if for no other reason than improved slug control!

Dragonflies, damselflies, water boatmen, pond skaters, newts and toads often help make up the main supporting cast but more unfamiliar creatures such as Grass Snake can visit the lucky few.

While it remains desirable that we recover our lost pond heritage through the creation of new ponds in the countryside at large, this must be undertaken with proper concern for: how they fit into the greater landscape; the enhancement of local wildlife value as opposed to simply creating a new habitat at a cost of an existing habitat of greater value and, of course, due regard for protections in place and any necessary planning and other consents.

The planning of garden ponds does not require adherence to such rigid standards, while still providing considerable benefit to local wildlife conservation. This said, it is preferable to use indigenous and locally occurring plant species and to avoid absolutely those alien species that can invade the environment at large with damaging effect.

Consideration too should be given to the immediate surrounds of your pond. Does it provide cover for emerging insects and amphibians? Does it link to a suitable wildlife corridor' -- providing a safe transport route to other important habitats? Is there the potential for pollution by run-off from roads or fertilised ground?

The good design, creation, stocking and maintenance of garden ponds is a subject sufficiently large to require an article all of its own, but there is plenty of advice and information available both in book form or on the Internet -- providing that you choose your sources carefully (the websites at the foot of the page may give you a good starting point).

However, if this piece does nothing more than to interest a handful of individuals to site a garden pond where previously a strip of tended lawn existed then some benefit to Oxfordshire's wildlife may hopefully result.