Are you aware that you plant species catalogued as invasive in the Atlas of the Ministry and that you advertise, photograph and even document it? That this could constitute an environmental crime? It's an interesting way to explore if you don't stop your efforts to consciously and voluntarily alter ecosystems...
Considering any exotic species as "invasive" or "potentially invasive" is a resource often used by biologists who study invasive species to dissuade us from cultivating any non-autochtonous species. This photograph shows what until now was the only Montezuma Cypress existing in the city of Madrid. "Was", of course, because the one I planted in my neighbourhood for the time being looks very healthy.
This comment, which I am not going to refute here, serves me to talk about the surprising drift that many conservationists seem to have taken towards positions that today seem to me indefensible from a merely scientific point of view. First of all, this drift is due to the vocabulary used by the promoters of invasion biology, which has very little scientific basis and leads to dangerous amalgams of concepts. As you probably know, invasion biology started with the publication in 1958 of Charles Elton's book "The Ecology of Invasions by Animals and Plants". Published in the middle of the Cold War, in a decade marked by the release of films such as The War of the Worlds, the use of a militaristic vocabulary with strongly negative connotations to refer to expanding exotic species has marked the entire history of this discipline. From the very beginning, invasion biology focused exclusively on studying the negative impacts of these species, without any interest whatsoever in the fit that these species could have in the natural processes and in the ecosystems in which they burst, particularly in the series of vegetation. As several studies we have already referred to in another article in this blog (Plantas invasoras de hoy y de ayer) have shown, species that are simply opportunistic or colonizing and that would later be replaced by more demanding species are often referred to as "invasive".
The Barbary sheep only owes to the pressure exerted by the hunters not to have been completely exterminated, after having been included in the national list of exotic species against the criteria issued by the biologists who have studied this species and who know it best.
If invasion biology has remained a marginal specialty in Biology as a whole, it has however decisively influenced the ideology of the ecological movement and vampirized significant public funds. To such an extent that its postulates today have a much greater weight than that of the scientists themselves when it comes to legislating. I have already denounced in this blog the unjustified persecution carried out against the Barbary sheep in the SE of Spain (El porvenir truncado del arrui), ignoring the opinion of the specialists who had studied it (1). The invasion biology is, today in Spain, the closest thing to a religion and whoever dares to contradict them is exposed to being attacked in social networks. The comment I have received this weekend is a good example of it and there are plenty of examples such as the Barbary sheep which show that preconception can outweigh evidence. When I heard that there were brigades dedicated to the complete eradication of eucalyptus trees in Galicia in order to re-establish the native forest, I naturally thought that this was an extraordinary loss of time. It makes no sense to start from scratch in a situation like the present one, in which time is crucial. They could perfectly have organized a small excursion to the "Souto da Retorta" to convince themselves that the presence of eucalyptus is not incompatible with the recovery of the native forest (El bosque imposible).
Where some see a land where eucalyptus has been completely eradicated and ready to be repopulated with autochthonous species I see a treeless land exposed to erosion. Couldn't a few eucalyptus trees have been left to protect the soil and the small oak seedlings? Without such protection, the native forest is likely to take much longer to develop. With an enemy like climate change on our heels, we may someday regret not having been more pragmatic and less purist.... / Picture: La Voz de Galicia
Misunderstood conservationism, carried to its ultimate consequences, prevents us today from reacting quickly to a phenomenon such as climate change. Invasion biology has imposed itself in our country as a kind of monolithic truth that very few people dare to question openly. Those who have risked doing so, like David Theorodopoulos almost 17 years ago (2), received sticks everywhere. That American biologist, however, did nothing more than say that it was ridiculous to differentiate species into indigenous and exotic and dedicate time and money to persecute invasive species. To illustrate this fact, this author often gives as an example in his lectures the numerous and surprising changes observed in the faunas in the last millennia. One such example is the horse, born in North America and disappeared from that continent just 6'000 years ago. Today it is considered an invasive species in North America. The same reasoning applies to many other controversial species, such as the tree of heaven for example, which had a holartic distribution in the Tertiary, before being eliminated from much of its area by quaternary glaciations. The conservationists crushed him by accusing him, among other things, of giving too general examples that did not conform to reality. Climate change, however, is clearly demonstrating that the short-sighted and fixist vision that governs our environmental policies has no future. Why, for example, planting Spanish firs exclusively in their very small current distribution area where this species is in danger of disappearing completely due to climate change?
Will ecologists one day accept the idea that in order to save a species like the Spanish fir, it is necessary to plant it in other mountain ranges farther north? / Photo: View of the Spanish fir from the Jardín BotánicoTorre del Vinagre, in the Sierra de Grazalema. / Autor: Consejería de Medio Ambiente y Ordenación del Territorio
The people involved in listing alien species and deciding whether or not they are invasive have lost sight of the scale of the changes we face. If it is already ridiculous to consider some species exotic on the basis of man-made borders and limits, doing so in a world in which the movements of species and ecosystems promise to reach a much larger scale than most of the studied territories gives an idea of how futile such an effort is. I think it is not useless to remind ourselves once again that climate change is not a future reality. Yesterday I was watching a TV programme and I was very struck by an overprinted message which said that by the end of the century Spain was expected to have a temperature rise of around 3 degrees since pre-industrial times. This is a huge mistake that could let people think that climate change is a matter of the future. The reality is that the average temperature in Spain has already risen 3 degrees since pre-industrial times (E pur si riscalda ) and the 3 degrees to which they refer are actually 3 additional degrees. In other words, by the end of the century the average temperature in many regions in Spain will have risen by at least 6 degrees since pre-industrial times. This is enormous and is roughly equivalent to a rise in vegetation of almost 1000 metres.
Twig of a young specimen of Torreya taxifolia planted in Waynesville, North Carolina (USA), outside its "natural" range, where the species is gradually becoming extinct. Thanks to the efforts of the Torreya Guardians, the species is expanding further north into areas that are much more favorable to it. / Photo: Connie Barlow
The possibility of future changes clearly wasn't in the plans of invasion biologists when they developped the theoretical basis of their "science". They are now incurring in contradictions by not admitting that the ecosystems they are trying to preserve are going to undergo major changes. As a consequence of this, many ecologists are becoming climate change deniers because they do not accept the implications this could have on their work. Most conservationists, however, are aware of the reality of climate change but claim, in an attempt to reconcile their ideas with an undeniable reality, that our ecosystems are resilient and will be perfectly capable of "fitting in" with the effects of climate change. Their main argument is that they did so in the past and will continue to do so in the future, without realizing that the conditions towards which we are moving are absolutely unprecedented (Back to Pliocene ). No matter how much we talk about climate change in the media, I fear that as long as we are not able to convince environmentalists that they are going to have to accept the consequences of climate change and come out of that kind of green denialism that many incur, we will not be able to move forward and start taking really useful measures for the future. Climate change, clearly, is rehabilitating David Theorodopoulos idea that invasion biology is a pseudoscience whose theoretical foundations do not resist the embite of reality...
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(1) Cassinello J. (2018) / Misconception and mismanagement of invasive species: the paradoxical case of an alien ungulate in Spain / Spain Conservation Letters | |
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(2) David I. Theodoropoulos (2003) / Invasion Biology: Critique of a Pseudoscience / Avvar Books | |
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