I have never understood that obsession of identifying cities as urban ecosystems. Not even as a metaphor to address the serious problems that its inhabitants suffer. Moreover, the use of that term can lead to confusion, since by identifying the city as an ecosystem, it follows a more friendly and «ecological» view of what it really is: an immense sink of energy, nutrients, resources and deaths, incapable, at least in the way we have planned them, of balancing their balance in the slightest. That is, they are really the antithesis of an ecosystem, which, by definition, seeks equilibrium and tends to the climax. To achieve this it has at its disposal tools such as resilience, in case it is affected by some mismatch. Obviously, when it exceeds its limit of elasticity and adaptation, it succumbs as such, and disappears, giving rise to a non-ecosystem, like the city.
In addition, the use of this false metaphor is always accompanied by the idea that biodiversity is the best solution to solve urban problems. Let’s look at some of them: hundreds of thousands of people die every year from causes directly related to urban pollution. Tens of thousands of people die each year from causes directly related to urban heatwaves. And many others because of indirect causes that are difficult to correlate directly with urban heat. Every year millions of cubic meters of water, precisely where they are most lacking, are evacuated by the complete waterproofing of the cities. And other causes such as noise, night heat, stress and traffic disrupt millions of people causing costly mental illness and psychic disorders.
Can anyone really believe that we are going to solve all these evils by increasing the number of birds, insects and butterflies in the cities?
It is true that those cities with better biodiversity rates also have better rates in quality of life and public and environmental health. But it is not the increase of biodiversity that has led to this better situation, but better planning and good management practices have allowed the increase of biodiversity.
If you really want to help those who suffer and bear all these serious urban problems, start by urgently permeating the cities so you do not miss a drop of rain; Fill the streets with trees, but changing the model of «tree size adapted to the ridiculous dimensions of the sidewalk» by the model «sidewalk wide enough to accommodate the largest tree that fits in the street.» Use the terraces and roofs to laminate the storm drain. Change the asphalted parking lots through woods. Expel the cars with diesel engines from the cities. Recover urban riverbeds unconsciously transformed into streets. Build green spaces where people really need them and not where less business can do the promoter of the moment; and connect them with each other and with the outside of the city. And etc., etc., etc.
When you have completed all of these actions, Nature, which is not only not silly, but much smarter than us, will flood the cities with increased biodiversity. But if we do not make it first healthy and habitable for humans, it will do no good to force Nature to conquer it in such unnatural way.
I already know that issues such as urban resilience, urban sustainability, urban biodiversity and urban renaturalization move a lot of money, but infinitely less than the health bill and the cost of rebuilding after floods and other natural disasters, so common that instead of natural disasters we should call it disasters due our urban and industrial disasters.
If we do not want our cities to end up being inhabited by zombies and walking dead’s, unable to pay the bill for the damage generated by our anxieties with the intention of, curiously, living better, let us cut this nonsense and let us get our acting together looking for better cities. All these people deserve it.