The complicated balance of necessary policies for biodiversity

On these pages we have recently introduced the modern definition of the concept of biodiversity, showing how it is connected to a complexity on several distinct levels, and we have reported some data which, taken together, indicate how the increase in biodiversity, in several different conditions, demonstrably bring several benefits. However, we have left open two important aspects, which serve to better define the boundaries of policies aimed at producing increases in biodiversity whose value is not questionable: how and where such policies can be implemented. Implicitly, in reporting the value of the increase in biodiversity we have referred to the variation of some specific parameters, such as the diversity of plant species, in specific contexts, such as a meadow, and for specific purposes, such as the amount of carbon dioxide immobilization carbon.

First of all, this implies that the increase in biodiversity, at different levels and in different contexts, produces different effects, which are not always desirable: it is clear that, for example, increasing biodiversity in our homes could be a general advantage from the point of view of life on Earth, but not for ourselves, involving the sharing of our spaces and our resources with numerous other species which we usually gladly do without – from table companions, such as for example rats and various species of insects, to parasites, such as other arthropods and various microorganisms, up to plants capable of degrading our furnishings and the very walls of our houses, continuing for a whole series of organisms that we have literally kicked out, ever since we decided to build a house instead of use a random bed for our shelter. Not only that: many of our food productions would be jeopardized by an excessive and uncontrolled increase in biodiversity, which would involve, for example, in the fields an extreme difficulty in harvesting on a scale sufficient to feed our communities and also a significant decrease in yields, due of competition and to the advantage of species other than those on which our food depends, because an ecosystem does not expand with spontaneous regard for our species, but adapts to make better use of all the available resources, even by taking them away from us.

These considerations, together with other similar ones that could be made, lead us to a first conclusion: the value of increasing biodiversity, as soon as this value is to be promoted without being in conflict with our own species, must be modulated to avoid evident negative effects. Not only that: extending the reasoning, it is possible to identify a considerable number of examples in which there is a contrast between a human life as comfortable as possible and the increase in biodiversity, for the simple reason that the former requires the appropriation of a number of resources limited only by our ability to consume them, while the second requires a limitation of such consumption at least sufficient to increase the consumption of other organisms, with respect to other organisms. This is the elementary translation of the contrast between the limitless growth of our population and that of the others, and in a reasoning of pure convenience it cannot be reconciled at least as long as resources do not start to run out and the damage to the ecosystem is not such, to advise against further reckless growth and to set an intrinsic limit. So which comes first, our ease or biodiversity and its benefits? What to prioritize?

The point is that the forced conciliation mentioned above, caused by excessive exploitation and by the conclusion that it is better to stop in order to avoid damage to our species, has already been necessary for some time, because the consequences of the uncontrolled growth of our species as a whole, and particularly of populations with a higher standard of living and greater consumption, have already reached the point of causing climatic damage, depleting many environments and causing disasters of various kinds, albeit on a scale so far limited to what will happen in the future if we’ll pretend nothing happened or if we can’t do anything but talk. At this point, rational environmental policies based on scientific knowledge, and not on easy-to-grasp pseudoscientific superstitions as unfortunately we often tend to formulate, are absolutely essential, and among these, precisely, those aimed at promoting the increase of biodiversity in the ways and in the places that are most suitable. As?

Giving large swathes of land over to wildlife might seem like a good idea. In Chernobyl, for example, even the European bison has returned, and wild animals of all species circulate among the ruined buildings: the forest, protected from radioactive danger, and the entire ecosystem have returned to an overall more biodiverse stage than before explosion, with a large, well-differentiated ecological network of producers and consumers that, taken as a whole, is more efficient at providing those ecological services that are beneficial to life on the planet (including our own). And yet, the abandonment of the territory can also cause a loss of biodiversity: it is known, for example, that the millenary grazing of alpine environments has produced an ecosystem with adapted plants that require the action of herbivores to shed light and avoid the growth of forests, including spontaneous orchids and other particular alpine herbaceous plants, together with butterflies and a whole chain of specialized consumers who feed on them. The abandonment of high-altitude pastures, due to economic reasons, produces rapid reforestation which, especially where fir wood takes over, implies a loss of biodiversity, not an increase in it.

Not only, therefore, as we said at the beginning, it is not possible to promote biodiversity everywhere and in a casual way, but also, counterintuitively, certain environments where the anthropic action is strong and millenary can prove to be more ecologically diverse than the environments which it would tend to in the absence of man. For this reason, policies aimed at increasing biodiversity must take into account two equally important aspects: the effects on the human population, which can also be counterproductive in ecological terms (for example, leading to greater land consumption if crop yields decrease), but also and above all the diversity of the impact of the various actions identified, depending the type of environment on which you intend to intervene. In ecology, simplicity does not exist, nor can solutions cut with an ax work: what works in one place and in certain anthropized conditions, can be counterproductive elsewhere. And that is why, beyond slogans, it is necessary to address scientists from many different disciplinesnot to ideologues or naive proponents of simple solutions, if we really want to reverse the trend of degradation that will increasingly endanger our livelihoods.