Haiti is running out of forests | Science

Haiti is running out of forests and, without trees, the rest of the wildlife is doomed. These are the two main conclusions reached by a group of scientists after reviewing satellite images of the island since the end of the last century and visiting the last redoubts of the jungle. The forest cover, already scarce after centuries of deforestation, has been reduced to a meager amount: only 0.32% of its primary forests remain. The percentage, according to the study, makes the survival of many of the species that were already endemic to Haiti unfeasible. However, other researchers consider the figures exaggerated.

The primary forests or primigenios are retreating all over the planet. Behind them remain, in the best of cases, landscapes so altered that, although there are trees, biodiversity is more reduced in number and variety of species. Haiti may be the extreme. By geographical position and climate (it rains 30% more than in the humid Galicia) should be as green as Cuba, Puerto Rico and other Caribbean islands.

Only eight of the 50 highest mountains preserve part of the original forest

However, the work, published in PNAS, It estimates that primary forests occupied only 4.4% of Haiti in 1988. Three decades later, in 2016, the last year analyzed, the area had been reduced to 0.32%. In absolute terms, a country with an area of ​​27,750 kmtwo, it only conserves about 85 kmtwo of its original forest. And there are figures that also show the fragility of the state of the western part of the island La Española: Up to 75% of the forest of the two Haitian national parks, Pic Macaya and La Visite, has disappeared since they were protected, only 35 years ago .

"The lowest forests on the island were the first to be cut (due to their greater accessibility) hundreds of years ago, so there is nothing left in the plains," the study's lead author, the study's biologist, said in an email. Temple University (USA) Blair Hedges. So they analyzed the mountains: of the 50 highest peaks that conserved virgin forests in 1988, only eight remain with a significant vegetation cover. Three unique mountains conserve a third of the primary forest (see photograph). At the current rate, the authors of the study estimate that in 2036 there will no longer be primeval forests in Haiti. This does not mean that there are no trees on the island, but they no longer fulfill their original function, they are almost decorated.

"We have not specifically examined the composition of non-primary forests, but our data shows that they are degraded, with the majority being very open canopy, closer to 10% than 70%. [de porcentaje de cobertura forestal] and, therefore, drier and much less capable of supporting the original biodiversity, "explains Hedges, who verified it by carrying out field work in a dozen mountains, both with forests and deforested, in which they observed an 83% reduction in wealth. of amphibian and reptile species, the two groups of vertebrates analyzed.

However, scientists not related to the research, but with Haiti, question its conclusions, in particular the extent of deforestation. One of them is the geologist of the Grand Valley State University (USA), Peter Wampler. In 2014, he published a Haiti forest cover analysis using the same data: images from NASA's Landsat mission. Their results indicated that almost 30% of Haiti was covered in green, which is 10 times more than what was believed until then and much more than the primary forest estimated now. The discrepancy can be in the definition of forest. For the UN, any extension of more than half a hectare with trees over five meters high and a forest canopy greater than 10% is forest. Meanwhile, primary is that which has still been freed from human action.

"I do not disagree with the authors' main conclusions that forest cover and biodiversity have declined in their study period, especially in the sites they have studied, but extrapolate their work in the field using Landsat remote sensing analysis. as they have done it is potentially biased and subjective, "says Wampler. What worries him is the use that can be made of his conclusions. "One of the reasons why I am concerned about the possible bias and subjectivity of this research is that erroneous estimates of previous forest cover have been used to propagate a negative narrative about Haitian subsistence farmers, as ignorant who destroy their environment "

Researchers from outside the study question the scope and causes of deforestation

Regarding the causes of deforestation, regardless of its degree, it is necessary to differentiate between the historical one, already started in pre-Columbian times, and the current one. Although this historical deforestation is more related to the expansion of slave agriculture, the acceleration observed now has other causes. According to data from world BankNearly 80% of the country's energy needs are covered by wood and charcoal.

However, a study from last March shows that the bulk of charcoal and firewood production comes from mesquite (Prosopis juliflora), a tree of fast growth and that supports the most abusive prunings. According to the researcher from the Stockholm Environmental Institute and co-author of this investigation, Robert Bailis, Haiti has lost a lot of primary forest, but "most of these losses happened a long time ago", which would rule out obtaining coal as a cause. Coal is not among the main causes. At present, Bailis concludes, "the landscape of Haiti is very degraded, but there is more forest cover than most people think".


Source link