Natural succession in a new garden pond

When creating a new pond, you may be tempted to introduce species, but ponds will develop naturally and watching the process of colonisation will be fascinating, as Cath Price explains in this latest blog.

As soon as anyone digs a new garden pond their first instinct is to buy things to live in it. Pause for a minute though, and consider how natural ponds develop.

A pond is a dynamic thing. In nature, nothing is static – ponds are ‘born’, mature, silt up, dry out and eventually are colonised by shrubs and trees. Management is required to maintain the pond as open water but the early stages of development will manage themselves, and watching the process of colonisation will be fascinating.

Assume you have a new pond, filled with rainwater and a substrate of sand and gravel. It really isn’t necessary to introduce plants, but if you feel you can’t live with a totally empty pond you might add one or two plants to start it off - a submerged oxygenating plant and something with floating leaves or an emergent plant perhaps, just so it doesn’t look too bald.

Choose native species for maximum wildlife benefit. (Read more about pond plants here).

If you know somebody with an established wildlife pond they might let you have cuttings. Don’t plant too much, as many water plants are fast growing, and you want to keep at least 30% of the water surface open.

Once the plants are in, just sit and wait. Within a few days (or even hours) you will find that diving beetles, pond skaters and water boatmen have found your pond and are making themselves at home.

Frogs and newts will quickly find new ponds, especially if there are already populations nearby. Toads prefer to breed in ‘ancestral’ ponds, so you will have to wait longer for those

A pond skater (Gerris lacustris) (c) Luke Massey/2020VISION

Neil Aldridge

Many insect families such as mayflies, caddisflies and dragonflies, and some annual water plants may establish themselves within the first summer, followed by snails, flatworms and submerged vegetation. Within two or three years a clean water pond can be as rich in species as one fifty years old!

Colonisation of new ponds was a subject that interested Charles Darwin, who noted that many freshwater species are particularly well adapted to dispersal and much more so than dry land species. This may be because wetlands are prone to drying up over time, and species have to move to a more suitable habitat as the pond ages.

Many aquatic insects can fly (eg. diving beetles) or are the larvae of flying adult forms (eg. caddises, mayflies, dragonflies), while others can readily be transported on the feet of water birds as eggs or small larvae. Darwin’s experiments with severed ducks’ feet suspended in an aquarium, described in On the Origin of Species, makes fascinating reading!

Common darter dragonfly (c) Janet Packham Photography

New ponds offer a particular habitat for creatures which thrive best in open, bare conditions, those which require inorganic sands to root in and those which cannot compete well with other species. Examples include false march brown mayflies, medium stoneflies, common darter dragonflies and saucer bugs. These ‘new pond’ specialists will disappear once the pond develops.

The new-pond phase is transient but a pond may have centuries to mature – don’t try to hasten the process and cut out a vital habitat! You may never have such a good chance of witnessing natural succession on your own doorstep again.