Page 24 - ALG Issue 4 2024

BIO-DIVERSITY
BUILDING A
SMALL WILDLIFE
POND
Why Build a Wildlife Pond?
In the last 100 years, Britain has seen the loss of up to 90% of its wetland habitats and as such, the creation of new aquatic habitat is crucial in the fight to save many of our native species.The country used to be so wet in fact, that malaria was once found in the British Isles, and a more appropriate mode of travel for large parts of the country would have been via boat or coracle.
This gives you an idea of just how dependent upon water our native flora and fauna are. Small ponds trump larger bodies of water when it comes to biodiversity, with their shallower margins providing greater opportunity for the establishment of plant life, and their dynamic nature continually creating new opportunities. Even a washing up bowl sized pond can be full of diverse taxa, providing opportunities for allotment visitors and residents, making them the perfect addition to your growing space. Species such as hedgehogs, that are excellent at taking care of garden pests, will visit shallow ponds as somewhere to drink, and amphibians and invertebrates thrive
in small ponds that do not contain fish. In summer months, birds and bats may visit
to feed on insects and furthermore, ponds provide great benefit to us humans too.
Choosing a Good Location
The size of your pond is completely dependent upon the space you have available, but don’t let limited space put you off – even a dinner plate sized shallow pool provides great benefits for wildlife. Choose a spot that receives partial sun, as a small pond that is not shaded at all may dry up too easily during warmer weather.Think connectivity – many species won’t travel to water without cover and as such, placing your pond next to trees, a hedge, longer vegetation or even a compost heap can greatly increase their value.
Building your Pond
Dig a hole and use either a liner or a pre-made container, such as an old washing bowl or shallow bucket, unless, you have a heavy clay soil or access to enough clay to fully line your pond. But be aware a shallow clay pond may very well dry up during summer months. If using a liner, remove any sharp rocks and consider lining the base
of the hole with sand to protect your liner.
Small ponds should generally be between 20-70cm deep. If using a liner, dig shelves
at different heights in the pond; – this
will allow for different aquatic vegetation and varying conditions within the pond
for wildlife to inhabit. Generally, the more diversity of physical structure, the more diversity of wildlife.These varying conditions are called ecological niches. Place rocks and gravel at the bottom of the pond; this will hold down your liner/container as well as provide habitat. Used creatively, you can make a sunken washing up bowl or another container appear as a very natural looking pond. Avoid adding soil or bark as this will negatively affect your water quality – plant submerged vegetation in baskets or sacks contain the growing substrate.
Plants and Pond Features
Filling your pond should be done with rainwater if possible. Once you are happy with the water level and shape of your pond, you may want to consider adding some plants and features to increase diversity.
You must make sure there is a sloped entry/exit to the pond, so that wildlife does not become trapped.This may be done with rocks or logs, which may also be used around the pond edge for a more natural look.
Avoid exotic and invasive plants! Unfortunately, many garden centres still stock invasives that are detrimental to
our native flora. Instead, consider native options, which will yield the best results for biodiversity.
Consider submerged oxygenating plants such as Hornwort (Ceratophyllum demersum) and avoid Elodea species. For floating plants, the Frogbit (Hydrocharis morsus-ranae) and white-water lily
24 | Issue 4 2024 | Allotment and Leisure Gardener