In 2021, the theme chosen for World Environment Day is the restoration of ecosystems and will mark precisely the beginning of the United Nations Decade on Ecosystem Restoration.
Thus, more or less intuitively, we could say that restoration consists of the recovery of ecosystems. Sounds easy doesn’t it? Well it is not too much. Let’s take the example that surely comes to mind first: we have a land cut down or burned, and in which we want there to be a forest again, just like the one there was before. Perhaps we can think: very simple, plant a few trees, and that’s it. At the end of the day, that is the way of proceeding, on many occasions, for public administrations and private companies to try to repair the environmental impact caused by their activities or, simply, to give themselves a facelift and offer an image “Green” to society.
The ground, that great forgotten
However, it is possible that planting a few trees is not enough, because let’s not forget that a forest is not a simple crop, but a complex system in which there are many interactions between its elements , starting with a very important one and that often goes unnoticed: the ground. Yes, the soil, which is much more than a physical space that supports the plants, since there are the nutrients and water they need to live, as well as housing a multitude of fauna and microorganisms that interact with each other and condition characteristics such as fertility or water retention capacity. Pollution, erosion, the impacts caused by fire … there are many factors that will modify and interrupt the processes that occur in the soil. Restoration activities must consider the state of soil degradation and be aimed at recovering it if they want to have more guarantees of success, even if they involve actions that are not always as showy as planting hundreds of trees.
And, following our example, there are many more factors that we must consider before launching into planting trees. We must study, for example, the connectivity possibilities that this future forest will have with other ecosystems , which will be a source for species to colonize the land, if seed dispersal agents will arrive, take the topography into account …
Restoration objectives
On the other hand, we must not lose sight of the goal of restoration: what do we want to restore? Although we have given the example of forests, these are not the only ecosystems that exist on our rich and varied planet: reefs, mountain meadows, wetlands, peatlands …
In addition, we do not always have to return to the original state, to begin with because in environments like the Mediterranean, which man has modified for centuries, it is practically impossible to know what the starting situation was. Also, we are not always going to want that. For example: the farmed fields so widespread in the northern plateau are today the habitat of a multitude of emblematic steppe bird species, such as the great bustard. Birds that, if they returned to a supposed “original” state of primary forest, would surely be displaced by others.
Faced with a more static and linear view of ecological succession and restoration years ago, today we have realized that what is really interested in recovering when restoring is, more than the species, the PROCESSES , since they are ultimately the ones who are going to offer us a guarantee of continuity. For example, if you favor the recycling process of nutrients in the soil, you will improve its fertility, and you can save yourself the continuous fertilization to make the seeds germinate or grow faster. And it is that, nature is wise and does not charge us for its service, so it seems logical to leave it, whenever possible, to do the work for us, right?
In summary, when restoring an ecosystem we have to take into account various components, which we can group as follows:
- History of the place : what elements were there, what do we want to conserve or recover, what has happened (topography, soil, connectivity …)
- Territory : characterize the climate, soil, vegetation and fauna of the place.
- Social element : if restoration seeks to provide something to a human population and offer an ecosystem service: leisure space, improving air quality, mitigating climate change, stopping erosion, etc.
- Dynamics : as we have said, ecosystems are not static, so we must be able to foresee how they will evolve in the future.
There are no unique recipes
I suppose that by now you will have realized that the restoration of ecosystems is something very complex, an activity for which it is very difficult to establish “recipes”, since each case will be unique and deserves a careful study.
Ecosystem restoration is an exciting science that seeks to recover that balance between man and his environment, and remedy the excesses that we commit in our fierce passage through the planet. And it is that ecological restoration affects our well-being and therefore should have much more importance on political agendas. As the Society for Ecological Restoration summarizes in its declaration of principles: “Ecological restoration is a fundamental tool to achieve the conservation of biodiversity, the mitigation and adaptation to climate change, the improvement of environmental services, the promotion of socio-economic development. sustainability and improvement of human health and well-being It is practiced locally but has global implications, since regional and global benefits are obtained for nature and people ”.
