Urban paddling pools as sources of life

  • Ikke bare til pynt: Selv i grunne vannspeil midt i byen, som her i Middelalderparken i Oslo, kan det legges til rette for økt biomangfold. Foto: Maritza Ilich Mauseth

    Not just ornamental: Urban biodiversity in Oslo.

    Photo
    Maritza Ilich Mauseth

With small adjustments, landscape architects and developers can facilitate life and biodiversity in urban ponds. A small insect that has survived the dinosaurs is the key.

Urban paddling pools as sources of life

Water has a strong appeal to people. You only have to observe how children behave when in close proximity to water, either in Spikersuppa in the city centre, the bathing pools in Nydalen or the ponds in the Palace Park.

‘They make a beeline for the water's edge and start playing with sticks and stones. Water is such an important element for people in the recreational context. Just looking at water does something to us. Observing movement in water, the reflections, how it sparkles,’ says Wenche Dramstad, who is a landscape ecologist and professor at the Faculty of Landscape and Society at NMBU.

‘You don't need to spend much time on Instagram to realise how important water is to us!’

Water is an attractive design element when forming landscapes in parks and cities. The ecological perspective also plays a role.

Maritza Ilich Mauseth has written her Master's thesis at the same department on this topic:

‘So little is required for a pond, a pool or a water surface – which was perhaps only initially intended to fulfil an ornamental or recreational function in an urban environment – to become a place where several species live and thrive,’ explains Mauseth.

Where there are dragonflies, there is life
Mauseth has developed a tool that landscape architects and developers can use to see whether the water feature they intend to include can become more than just an aesthetic element – a place teeming with life.

To determine whether there is life in the water, be it a newly opened stream, a beautiful pool in a park or a flat water surface in Oslo city centre, Mauseth has chosen to take a small, and to many a modest creature, as her point of departure, namely the dragonfly. This small insect has been burdened with an ominous name. While the English and Danish (‘gulsmede’) equivalents are more poetic, the Norwegian ‘øyenstikker’ (lit. eye stinger) is enough to scare even the most well-intentioned insect enthusiast.

But the dragonfly (eye stinger), or 'ear crawler' as it is called in the Nordland region, does no harm whatsoever to either our eyes or our ears. However, it is a predator, deadly for midges and flies that frequent ponds, and to tadpoles, beetles and midge larvae that live underwater.

Even more important is that the dragonfly is what is known as a bioindicator. This means that it can give us information about the environmental conditions. If, for example, such a species turns up in water that used to be polluted, that probably means that the quality of the water has improved and that many other species will probably be able to thrive there as well.

‘Biodiversity is under threat, among other things due to increasing urbanisation over time. When we investigate whether there are dragonflies in the lakes and ponds in our cities, we also learn whether there is a basis for life and whether there are other species in the lake or in the area,’ says Mauseth.

There are eight different species of dragonfly that are regarded as endangered in Norway, but as Mauseth elaborates: ‘It wouldn’t be right to just focus on those that are endangered today. Species that are common today can become endangered tomorrow unless we take conscious steps to facilitate biodiversity when we develop an area.’

Urban ecology: Mauseth at the Hovindammen in Oslo.

Urban ecology: Mauseth at the Hovindammen in Oslo.

Photo
Nanna Baldersheim

All species are important to the ecosystem
Biodiversity is crucial to the whole ecosystem, also in cities, whether it concerns a little puddle or a whole city district. If we lose one species in an area, we can quickly lose many others as a result, because they depend on each other. Ducks with their cute ducklings, which are such an important feature of city parks for pensioners, children and all the rest of us, eat dragonflies. Dragonflies eat other insects. And so on. Species we perhaps do not normally set great store by can turn out to be important in mitigating changes to the ecosystem.

Vital planning
‘There are certain factors that come into play when dragonflies decide where to settle. The type of edge surrounding the water, whether it is a straight, hard concrete edge, as in Spikersuppa, a small sandy beach or vegetation, such as rushes, or perhaps both. Open water exposed to the sun, plants such as water lilies and the pH value of the water are other elements that determine whether the insect can thrive in a particular environment or not,’ says Mauseth.

But it’s not a given that developers will take biodiversity into account when drawing up their plans.

‘Historically, it has been a challenge to bring together planning, design and ecology to form a well-functioning whole,’ says Dramstad.

‘I believe it’s because people work to different time scales, and there are different interests and clients whose demands have to be satisfied. But as this master's thesis shows, a little can go a long way and a planned landscape element can be given a new and important additional role. One and the same landscape element can have several functions. This means that many more can contribute actively to conserving biodiversity. It is well documented that in this context, we need everyone who is willing to contribute.

A challenge for developers
Dramstad underlines that developments are positive as regards cooperation.

‘There is much more awareness of ecology and diversity than there was ten years ago. Water is a particularly tricky element to manage and work with, however. Just think about algae growth, littering, smells – a beautiful lake or stream can quickly lose its appeal. Not to mention the safety aspect. Water is also an element with the potential to fill many functions. I hope the developers will accept this challenge as well,’ she says.

Obos is one of the country’s biggest developers. They report increasing environmental awareness in planning work in recent years, but confirm that water is a difficult element to work with. Outdoor areas have to be maintained after the residents have moved in, and water elements can result in significantly higher joint costs and extra work.

‘We build housing and outdoor areas that people are expected to enjoy living in for many years. In our experience, our customers want outdoor areas that offer good opportunities for recreational activities, while at the same time being easy and affordable to maintain,’ says Åge Pettersen, Communications Manager at Obos.

A predator insect from prehistoric times
However, our little insect cares little about joint costs. The dragonfly is part of a much bigger picture, and its history dates back somewhere between 280 and 350 million years. In other words, it coexisted with the dinosaurs. The original dragonfly had a wingspan of 70 cm and, at that time, was a predator worth keeping an eye out for.

‘An insect that is this old and that has adapted to such a degree, and continues to do so, might well have something to tell us in a world where nature is under threat and we are becoming increasingly urbanised,’ says Mauseth.

‘They are also incredibly beautiful!’

Photo
Foto: Shutterstock/Subbotina Anna

 

 

Published 1. September 2020 - 13:40 - Updated 9. September 2020 - 13:39