At the end of the 19th century, more than 75% of the territory of the city of Porto was covered by green spaces. 100 years later, these spaces represent less than 30%, a decrease of approximately 60% due to the growth of urbanisation.
Trees, which covered 17% of the city’s surface in 1892, only represented 8% by the year 2000.
“Associated with the decrease of Porto’s green spaces is the major transformation in its spatial structure,” says Marta Pinto, of the municipal department of environmental planning and management for Porto. “Specifically, we have high levels of fragmentation and discontinuity of green areas, which greatly reduces the functionality and connectivity of the region.”
In the last decade, the municipality of Porto has committed to the enhancement of its green infrastructure, through the connection and densification of green spaces, including natural and semi natural areas such as parks, gardens and woodlands.
“The goal is to design a liveable, healthy and resilient city,” says Pinto.
One of the initiatives to work towards this commitment is FUN Porto, Porto’s urban native forest initiative.
Green cover
One of FUN Porto´s ambitions is to produce, and reintroduce, native tress for public spaces and private gardens and contribute to the conservation of rare native plants.
Other ambitions include raising public awareness about the benefits of trees; encouraging residents, citizens and organisations to plant native trees in their gardens; and reintegrating nature in unused areas of the city, known as biospots – such as alongside motorways and road verges that have a great potential for increasing biodiversity.
Work on FUN Porto first started in 2013. Since then, Porto’s Native Tree Nursey has produced more than 76,000 plants, and has run trials to bring back 9 threatened native species. In addition, the municipality has given away more than 45,000 native trees to other municipalities in the region that have their own ecological restoration operations underway.
Each year, the nursery produces 10,000 plants and maintains a stock of 15,000 native trees.
Forgotten spaces
The implementation of the project has not all been plain sailing.
“We are currently undergoing a fourth monitoring campaign in the BioSpots Network,” says Maria Almeida, from the Catholic University, a partner with Porto in the FUN project.
The BioSpots Network is an essential part of the city’s green infrastructure: not only in terms of biodiversity, but also for removal of air pollutants, reducing the carbon footprint of the transport sector, landscape softening, maintaining ecological coherence in the landscape, improving the visual aspects of road travel, and reducing the high maintenance costs of these spaces.
“We’re learning lessons,” Almeida continues “because the first time we checked on these new biospots where native flora was reintroduced, after the first year, the survival rate was 70%, and 2 years after planting it was 66%.”
The main reason the team noticed for this was the non-adaptability of three species to the environmental conditions in these areas.
Another barrier to this project has been the lack of obvious space into which it is possible to expand the green areas and to install native trees.
“We have had some difficulty in mobilising private owners that could make available more areas for this network,” explains Almeida.
Just like any other urban area, “a love hate relationships exists between people and trees in this region,” says Pinto. “This conflict can be finalised by demonstrating that trees have a far greater value than the general public perceives. For example, the impacts of woodlands on our health,” she concludes.
Private gardens represent around 8% of Porto’s green spaces and the municipality wants to find ways to support residents who want to contribute to Porto’s biodiversity. Residents who want to receive trees must fill out an application, which the city uses to promote good town planning.
So far, more than 1,300 applications have been accepted in 3 rounds, and the city has given away 6,000 trees, to approximately 1,000 families. In the 2021 round, another 2,900 native trees are being made available for residents.
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