October 18, 2016 Biodiversity Written by Sara Slavikova
Lawn, a green killer of biodiversity
Many of us probably haven’t ever

thought of our backyard as an important spot for local biodiversity, but when it comes to nature every spot that is not sealed by concrete counts. Green spaces in densely populated urban areas often serve as the last isles of habitat for native species of plants, insects, and small animals. Surprising as it may sound, their fate often does not depend on the municipality but lies in the hands of the private land owner. For example, in London approximately 24% of green land cover fell under private ownership in 2010. And the number could have been even higher, had 12 % of green spaces not been replaced with the biodiversity-killing infrastructure within the last decade¹.

However, backyards and gardens are still one of the major contributors to green space within a city. This means that they represent a great chance to re-create little bits of fully functioning ecosystems. The benefits for local species could be tremendous, considering that their original habitats have been forever lost to urban development. But there is a problem with all that: perfect monoculture lawns with their constant demand for irrigation and nutrients.

Lawns are an irreplaceable part of the modern dream. And their maintenance has become a weekend routine for many. Historically, a flawless lawn represented the wealth of a property owner. It meant that the owner had enough land to produce from it and could even afford to keep some just for aesthetic purposes. Nowadays, this point of view has to change. Monoculture lawns are easily comparable to wastelands when it comes to biodiversity richness. We tend to believe that a thick green lawn is a sign of healthy ecosystem, when in fact, it is the most life deprived part of a garden.

What can be done to have a nice garden and be nature friendly?

The answer is simple – native plants.

When you grow native plant species in your backyard, you are providing a great service for the local environment. Patches of native plants are a magnet for small wildlife, such as chittering songbirds, or colorful butterflies, because they create a suitable habitat for them to feed, reproduce, and settle. Every species of plant has developed a special chemical that influences the taste of their leaves, or can even make them toxic. Insects and animals that have evolved in the same area as those plants have undergone a long process of adaptation to be able to digest them. And in many cases their organisms need these specific chemical compounds. But when native plants are being extensively replaced with a perfect monoculture lawn and a few exotic trees, available food sources for many native insects decrease. For example, imagine colorful butterflies, who need to suck nectar from flowering plants to nourish their body².

In the past, it was believed that reducing the numbers of insects was a good thing otherwise they would eat and destroy your garden. But when a plant does not pass on its energy, it cannot meet its function in the food web. And the number of species that live in an area depends on the diversity of the vegetation, because plants fulfill the basic needs of the majority of local species. That is the reason why we have to think of our garden as a place with the great potential to conserve life and enrich local biodiversity. In the end, who was it that decided that a beautiful garden equals uniform carpet-like lawn?



¹ https://goo.gl/g9HGaw
² http://www.joyfulbutterfly.com/what-do-butterflies-eat/