Can a panorama with out bushes be a useful and wholesome ecosystem? The solution is a convincing sure. With greater than 650,000 hectares affected, the catastrophic megafires of 2025 within the west of the Iberian Peninsula drive us to reconsider the control of the herbal surroundings. Clinical proof presentations that afforestation of Mediterranean heaths and thickets with pine or eucalyptus now not best destroys biodiversity, erodes soil and will increase water pressure, but additionally creates veritable mud packing containers: homogeneous landscapes which can be a lot more flammable and no more resilient.
Some distance from being passive sufferers, many Mediterranean ecosystems had been formed through hearth all over their evolutionary historical past. They now not best tolerate fires, they rely on them. Those are flammable and pyrophilic landscapes (actually, hearth fans) which, mockingly, would undergo a major biodiversity disaster if hearth had been utterly eliminated.
Probably the most paradigmatic instance within the Iberian Peninsula is the Mediterranean heath or herriza, a singular subtype of Ecu dry heath that covers the excessive slopes and summits of the siliceous mountain levels of the western part of Iberia, from Galicia and Asturias to the Strait of Gibraltar. This is a dense thicket ruled through heather, rose and gorse, flammable and pyrophilic species, and is characterised through the sensible absence of bushes.
Above: Herrizona within the Azoreira mountain vary (between Ourense and Zamora). Beneath: grassland within the Oyen mountain vary (Tarifa, Cádiz). Fernando Ojeda The Fantasy of the Degraded Mountain
Regardless of the nice variety of natural world, herriza has traditionally been regarded as a degraded habitat because of the loss of bushes and occasional productiveness because of the low fertility of its soil. Subsequently, because the center of the 20 th century, those heaths had been regarded as ultimate landscapes for “restoration” thru mass afforestation.
The State Woodland Heritage – a company that depended at the then Ministry of Agriculture of the Franco dictatorship – has in large part remodeled them with pine and eucalyptus plantations. For conifers, black pine, Pinus pinaster, sometimes called pitch pine, a species local to the west of the Mediterranean basin, was once selected. The similar trend was once repeated in parallel in Portugal, through the then Direccao-Geral dos Sources Florestais.
Resin pine: recovery or profitability?
The concern number of this tree was once now not unintended. Its standing as an autochthonous species was once essential, giving a way of herbal renewal to the status quo of wooded area plantations. It’s true that there are herbal formations of Pinus pinaster within the siliceous mountain levels of the Iberian Peninsula and North Africa, however those are virtually all the time remoted stands on rocky ridges on scarce land at greater than 1,000 meters above sea degree.
Those stands are these days labeled as relict forests and habitats of neighborhood pastime through the Ecu Union. On the other hand, even though a protecting rationale in opposition to soil erosion and clogging of reservoirs was once additionally given, the definitive argument for afforestation of “unproductive” meadows and sparse forests was once financial. The resin pine promised juicy non permanent profitability because of the mass manufacturing of wooden and resin.
The chimera of protecting afforestation
What the forestry government of the time, each in Spain and Portugal, didn’t foresee was once that their efforts to change into those “unproductive” heaths would in the end take a heavy ecological toll. Lately, when put next to those that shield the meant luck of the ones plantations in restoring the panorama or mitigating local weather exchange, the medical proof issues to the other.
A number of research query their protecting function in opposition to soil erosion and water loss, whilst caution of the way they threaten local biodiversity. When it comes to local weather mitigation, the pitfall is apparent: lots of the carbon in pine forests accumulates within the aerial biomass (trunks and crowns), now not underground. As a result of bushes are so flammable as a result of their resin, they’re at risk of burning, so their medium to long-term carbon sequestration capability may be very restricted.
Moreover, afforestation enormously will increase the flamable biomass of the panorama. This, in conjunction with the intense climate stipulations of local weather exchange, explains the catastrophic severity and scale of the megafires we already bear.
The true drama of this wooded area type is unleashed through hearth. When those dense pine forests burn, the large accumulation of biomass creates wildfires of abnormal depth that actually burn the bottom. Excessive warmth destroys seed banks, regeneration organs (similar to roots, rhizomes and vines) and soil microbiota, threatening the herbal regeneration and resilience of the unique ecosystem earlier than reforestation.
An indigenous species that behaves like an invasive
However the affect does not forestall when the flame is going out. Some distance from backing out, pitch pine takes benefit of the post-fire state of affairs to begin huge seedling germination. This permits it now not best to deal with itself in burnt plantations, but additionally to invade neighboring heaths or wooded area ecosystems.
Many years of man-made variety and forestry engineering – inquisitive about discovering fast-growing, high-performing bushes – in the end “domesticated” the species, amplifying its maximum colonizing characteristics. The result’s an alarming ecological paradox: the organic invasion of herbal habitats through an indigenous species whose ecological standing now we have modified thru synthetic variety.
Pitch pine wooded area (Pinus pinaster) in Jedra gorge, Ávila. 19migmas63/Wikimedia Commons, CC BI-SA Pyrodiversity: why hearth isn’t all the time the enemy
Briefly, ecosystems similar to herizza have an innate talent to regenerate after hearth. It’s an ecological idea of resilience. This procedure, after all, takes time: it is going to take about 10-15 years to go back to the state earlier than the fireplace.
Why rush? There may be ceaselessly an insistence at the pressing recovery of the burnt panorama so as to offer protection to the natural world, forgetting that many species want the ones first years after the fireplace to live on. In ecology, we use the idea that of “pyrodiversity”: a mosaic panorama with spaces of various ages after the final hearth and containing other related species. This is, pyrodiversity generates biodiversity.
Ecological forestry and schooling: keys to the mosaic
Then again, it’s value remembering that herbal forests of Pinus pinaster have a excessive ecological worth; the issue isn’t them, however fashionable synthetic plantings. The abandonment of those monocultures, in conjunction with local weather exchange, became them into homogeneous plenty stuffed with flamable biomass and vulnerable to high-intensity fires.
Panorama mosaic of the valley of the river Miel (Algeciras, Cádiz). Herica at the ridges, floating oaks at the slopes and gall oaks within the backside of the valley. Algeciras and Gibraltar within the background. Fernando Ojeda
To opposite this example and repair biodiversity, not too long ago burned plantations be offering a strategic alternative for recovery. The bottom line is to forestall the spontaneous unfold of those plantations thru lively control and ecological forestry. Likewise, a transformation in environmental schooling is urgently wanted to take away the “forest-centered” imaginative and prescient that prevails in society.
Trees and heaths don’t seem to be “dirty forests” or degraded levels of crops, however precious reservoirs of biodiversity that are meant to now not be artificially forested and the place hearth acts as an crucial herbal component for his or her construction and capability.
