Biodiversity in the urban nature

Through a so-called LONA project, Skellefteå municipality has produced signs about the biodiversity in the urban nature and put them up in various places around the municipality.

The project aims to raise awareness about biodiversity and the benefits of nature that are right on our doorstep. Below you can read the full translation of the signs. The illustrations are made by Gun Löfdahl.

Rocky pine forests

Rocky pine forests are a common type of nature found on the mountains we can see in our urban environment. These lands offer such low productivity that they have not been used for forestry. The terrain has also made them difficult to develop.

As a result, many of the pine trees have been standing here for as long as 200–300 years. This means that rocky pine forests often contain great natural values, primarily in the shape of lichens, insects and birds that are dependent on old trees. The forest is open and dominated by low-growing pine while the forest floor is covered by a mix of open rocky ground covered in lichens, heather, lingonberry sprigs and small damp areas.

Why doesn’t the municipality cut the grass?

Grass is managed differently in different areas. In areas that are used more frequently, such as parks, the grass is cut regularly and smaller bushes and plants are cleared. In other environments, this vegetation is left to grow tall and flowers to spread their seeds.

Managing grassy areas in different ways creates a varied environment where grass and herbaceous plants can flower throughout the season, creating homes and food for insects such as bees, bumblebees and butterflies. The greater the variation in the surrounding nature, the greater the number of species that can live there, resulting in greater biodiversity.

Less grass cutting also means less greenhouse gas emissions.

Why doesn’t the municipality clean up the forest?

A natural forest may seem a little messy, but only because we aren't used to them. Dead trees and brushwood may look like forest waste, but they’re quite the opposite. Due to modern forestry, few trees reach old age and die a natural death. This has made deadwood scarce, resulting in many species that are dependent on deadwood being threatened with extinction.

Insects are not the only animals that appreciate deadwood; bats, birds and hedgehogs do as well. Increasing the amount of deadwood in urban natural environments provides more species with homes and food. It is also important to allow new trees to grow naturally so that they can take over when older trees die.

The most important breakfast in the world

Sallow is an extremely important tree species for biodiversity. Old, broad sallow trees provide food and homes for countless caterpillars. Additionally, many beetle species eat the tree's leaves, flowers and buds.

Sallow trees love sunlight, and so you often find them in open landscapes such as at the forest edge, on overgrown cultivated lands and in forest glades. They are easily recognised in the spring when the buds, or catkins, open. Sallow trees flowers first of all plants, just when the queen bumblebees wake from their long winter hibernation, ready to provide food in the shape of pollen and nectar. In return, the bumblebees pollinate the sallow trees. The many insects around the sallow also ensure that there is plenty of food for small birds early in the season.

Sallow is a so-called dioecy, meaning that the male and female flowers are found on separate trees. The male trees have bright yellow stamens, and the female trees have pale green pistils.

Plenty of bats

Bats are the only flying mammals, and thanks to their ability to navigate by echolocation, they have proved highly successful. Today, every fourth mammal on earth is a bat.

In Sweden, all bats are protected species and must not be disturbed, captured or killed. They eat insects and can eat as many as 7,000 mosquitoes in a single night.

Bats thrive in open landscapes with groves, forest edges and open bodies of water. Just like many other species, they need deadwood, as both a home and a place to find insects.

Bats are nocturnal and thrive in the dark. The city's illuminated environments pose a problem and disturb their normal behaviour.

The beaver – a skilled conservationist

The beaver is the forest landscape equivalent of the elephants and termites of the savannah. It creates its own habitat with major consequences to the surrounding environment and other species, and therefore it's considered an ecosystem engineer.

The effects of the beaver's dam building are seen not only where the beaver lives, but also several kilometres upstream. When a beaver abandons an environment, the landscape changes again.

Wetlands created by beavers exhibit greater biodiversity than wetlands created without the involvement of a beaver.

Invasive species

In certain places in Skellefteå municipality you can find the Himalayan balsam, an invasive species that does not grow here naturally and risks wiping out plants and insects. The plant quickly covers large areas and suffocates other plants. Since it produces large amounts of nectar, insects are happy to visit the Himalayan balsam, which can make pollination difficult for other flowers. Since its flowering season is quite short, there is also a risk of insects starving because other flowers have been wiped out.

The Himalayan balsam is one of the species that both the EU and Sweden have decided needs to be completely eradicated. It poses a threat to biodiversity, which is the foundation of human survival.

The plant is relatively easy to combat and can be pulled up by hand. As it is an annual plant, only the seeds can form new plants. Plants that have been pulled up can be placed in bags and thrown in a green waste bin or the appropriate container at the nearest recycling centre.

If you find Himalayan balsam, we would like you to report it via the website invasivaarter.nu External link, opens in new window.

Clean water – an ecosystem service

The water than runs down our streets and over our rooftops is called stormwater and is most often led through underground pipes to the nearest waterway or lake. Cities with hard surfaces generate up to ten times more stormwater than surfaces covered in vegetation. Poor stormwater management increases the risk of flooding and pollution in lakes, waterways and, eventually, the sea. When rain and melted snow runs through the city it takes pollutants from vehicle exhaust fumes and tyres with it.

Letting nature filter the water before we discharge it into lakes, waterways and the sea is a better idea. If stormwater is allowed to evaporate, soak into the ground and be absorbed by plants, we prevent flooding and the water is filtered. This also helps maintain natural ground and surface water levels and improves the microclimate. Nature filtering water for us is known as an ecosystem service, a natural benefit. Nature's processes enable our wellbeing.

The riparian zone

The riparian zone along the waterways of Skellefteå are home to many plant and animal species worthy of protection. The vegetation growing in the riparian zone also acts as a filter, absorbing nutrients and pollutants that would otherwise reach and pollute lakes, streams and the sea.

In shallow waters, sunlight reaches all the way to the bottom and quickly warms the water. Rocks, stones, gravel and sand create protected environments rich in food, allowing fish, plants and insects to thrive. Even birds and mammals seek out food, find shelter and raise their young in the riparian zone.

The vegetation growing along banks also acts as a corridor for animals to follow and plants to spread. In the long term, this enables species to spread to different places and maintain the genetic variation that better prepares them for altered environmental conditions, such as climate change.

Broad-leaved jungle

This is a place where nature thrives, able to be wild and go its own way. It may look a little messy, but it attracts countless different plant and animal species. Biodiversity demands variation. The greater the variation in habitats, the greater the number of species in an area.

Modern forestry has led to a lack of old forests, trees of varying ages, broad-leaved trees and dead wood. This has resulted in the species living in such habitats declining as well. Some 200 threatened species are dependent on broad-leaved forests. One of them is Sweden's most threatened bird, the white-backed woodpecker. By helping the white-backed woodpecker, we also help many other threatened species dependant of the same environment.

This is why it's important to protect our broad-leaved forest environments and to create new ones. The city's broad-leaved forests can prove valuable if we care for them in the right way.