Towns and cities have increasingly become hostile to biodiversity. Fortunately, a few years ago there is a growing interest to make cities more friendly to the native fauna and flora. Discover what you can do for urban biodiversity!
HOW CAN YOU HELP BIODIVERSITY OF THE CITIES?
According to SEO BirdLife, 10% of the bird species that live in Spain are housed in urban environments. In fact, some of them, like the sparrow, depend on human presence. In spite of that, these species are in decline.
They also assure that urban birds in Spain have suffered a decrease of over 18% in the last 20 years. For the case of the barn swallow (Hirundo rustica), the loss amounts to 44% of its individuals.
BENEFITS OF URBAN BIODIVERSITY FOR PEOPLE
Biodiversity in cities is positive for human beings, beyond the ornamental function, since it offers a set of very important services that improve our quality of life. In fact, the WHO recommends that in cities there are between 10 and 15 m2 of green areas per inhabitant and that the inhabitants have a green area less than 300 m from their house.
In addition to the benefits that nature has for human health and well-being, green areas cushion the temperature (important to reduce the effect of heat islands), purify the air and fix CO2. It is also responsible for the pollination of crops and, in general, to increase the resilience of the environment.
WHAT CAN WE DO FOR URBAN BIODIVERSITY?
Broadly speaking, to help the biodiversity of cities, we must:
- Provide enough urban green areas in the cities and that they are distributed throughout the area.
- Have urban green spaces connected between them and with the natural environment.
- Generate diversity of habitats.
- Do not plant invasive species.
- Do not use chemical treatments.
- If the green areas are illuminated, make sure it is not annoying for the fauna.
We must bear in mind that, if we have cats at home, we must consider if it is worth doing some of the actions we propose, since our feline friends are great predators and, rather than helping the fauna, we could be harming it.
PLANT TREES, BUSHES AND FLOWERS THAT PROMOTE BIODIVERSITY
Obviously, if we plant native trees or shrubs we will be favouring the biodiversity of our city. If we do not meet this first point and plant exotic invasives, we will be questioning the future of our area. In addition to this fact, we must add other considerations.
The trees or bushes that produce fleshy fruits, such as the olive tree (Olea europea), the strawberry tree (Arbutus unedo) or the lentisk (Pistacia lentiscus), will be able to sustain a part of the diet of some animals. The olive tree also generates holes, which may serve as a nest for some birds. If we look for species that bear fruit in winter, when conditions are more difficult due to the reduction of food, it will also be of great help.
Softwood trees, such as poplar (Populus), will allow some birds, such as the Iberian green woodpecker (Picus sharpei), to make holes in its trunk, which will cause that when leaving the nest other species can be installed. We can also leave dead trees standing for the Iberian green woodpecker to make its nest.
Combining deciduous and perennial trees will allow a refuge for wildlife throughout the year.
As for the plants, it is highly recommended to plant indigenous aromatic plants, which will attract a large number of pollinating insects. In the Mediterranean area, you can choose rosemary (Rosmarinus officinalis), lavender (Lavandula stoechas), savory (Satureja montana), thyme (Thymus vulgaris), sage (Salvia officinalis), basil (Ocimum basilicum)…
INSTALL NEST BOXES
If there were old trees in the cities (and in the natural areas), it would not be necessary to install nest boxes. The reason is that the old trees have holes, in which the chickadees, the tits, the owls, etc. make a nest. But not only can you install nest boxes for birds, you can also do them for bats, which are effective mosquito eaters.
On the other hand, there are animals that use buildings to breed, such as the peregrine falcon (Falco peregrinus), the kestrels, the crow (Corvus corax), the common swift (Apus apus), the common gecko (Tarentola mauritanica), etc. .
In general, in the Iberian Peninsula there are about 40 species of birds and a dozen mammals that can use nest boxes to breed and rest.
In this Grup Ecologista Xoriguer and VOLCAM Voluntariado Ambiental‘s guide you will find information about how to build yourself a nest box and other tips.
BUILD A INSECT HOTEL OR OTHER STRUCTURES FOR FAUNA
An insect hotel is a construction with a wooden structure that is full of different materials, such as natural cane, stones, tiles, bricks, pineapples, perforated wood or straw, which serve as a hiding, resting and breeding place for various species of insects.
Although you can buy them, we recommend you do it yourself with a little imagination. Collect these materials and about 6-7 wooden pallets and start to build a new home for solitary bees (solitary bees are not aggressive, unlike colonial ones), ladybugs (they will eat the aphid you have in your garden), lacewing, syrphids…
The construction of dry stone spirals with aromatic plants will also favour the presence of fauna, especially reptiles.
In a corner of your garden, you can leave a pile of trunks in the shape of a pyramid. You will see that in a while it will be colonised by mosses, fungi, xylophagous insects, lizards…
VEGETATION MAINTENANCE TASKS
All this is meaningless without sustainable maintenance of green infrastructure. What good is it to plant trees with fleshy fruits if we prune them in full fruition?
Here are some tips:
- Do not prune in the time when the trees are in fruit, concentrate them during the winter.
- Avoid pruning all trees and shrubs the same year.
- Decrease the number of prunings and ask that they be less drastic. So there will be structures that can support large nests.
- Do not remove all the leaves from the ground, since leaf litter allows the development of the invertebrate fauna and incorporates organic matter into the soil.
- Do not use chemical pesticides or phytosanitary products. If you have a pest, use biological control systems against them.
ASK YOUR LOCAL ADMINISTRATION TO JOIN IN THE PROMOTION OF URBAN BIODIVERSITY
Some of these tips will be easy to implement, others will be less. In addition to applying it in your own home, ask your local administration to apply these principles. Together we will make towns and cities more sustainable in which biodiversity can also live!
In addition to the points already mentioned, local administrations can do some other tasks that are within their competence:
- Naturalise artificial lakes. What if, instead of having ponds with crystal clear water, we took advantage of these points to favour the presence of amphibians, reptiles and aquatic vegetation?
- Change lawns for natural meadows. What if instead of having large expanses of green grass, typical of northern Europe (where water is plentiful), we had spaces with different species of native flowers that attracted large numbers of pollinators and birds? Some birds, such as the zitting cisticola or streaked fantail warbler (Cisticola juncidis) or the European stonechat (Saxicola rubicola), make nests in the middle of meadows.
- Reduce the mowing of the lawns (better done at the end of winter) and make differential mowing. What if instead of completely mowing the lawn we did it irregularly to allow the growth of spontaneous vegetation that attracted the invertebrates?
- Plant in the tree clogs. What if instead of having tree clogs full of dog droppings we had them full of flowers that attract the insects that control the plagues of the tree that is planted in it?
Have we encouraged you to apply any of the measures we present? Tell us what you are doing to help urban biodiversity in the comments of this article.
(Cover picture: Kevin Cole, Creative Commons)