The Intergovernmental Panel on Climate Change (IPCC) indicates that deforestation is part of the ten major environmental problems of the planet and seriously affects humanity because it is related to other difficulties such as species extinction, floods, erosion, and atmospheric pollution.
In the case of Mexico, according to the National Forestry Program 2020-2024, published in the Official Journal of the Federation by the Ministry of Environment and Natural Resources, our country loses its forest cover due to illegal activities, such as change of land use, clandestine logging, trade of raw materials and products, fires, pests, and diseases.
"To the extent that trees are cut down, several important environmental services disappear, such as hosting much of the country's biodiversity, slowing climate change, regulating the water cycle, preventing soil erosion, and supplying us with wood and non-timber forest products; providing an attractive landscape," warns Martin Ricker, head of the Botany Department at UNAM's Institute of Biology (IB).
The National Forestry Commission (Conafor) reports that from 2001 to 2018, 212,70 hectares were deforested per year, almost all to gain grasslands and to a lesser degree agricultural land. The situation is especially serious in southern Mexico: Campeche, Oaxaca, Chiapas, Yucatan, and Quintana Roo, although also in Jalisco.
However, these data do not take into account the degradation of forests and jungles, when they are altered without being deforested. That is, by extracting wood or changing the structure of the site, says the university academic on the occasion of the International Day of Forests, which is commemorated on March 21.
In 2012, the United Nations General Assembly proclaimed it, to pay tribute to its importance and generate awareness about it. In Mexico, five main forest types can be distinguished: coniferous forest, broadleaf mountain forest, mountain mesophyll forest, evergreen forest, and deciduous forest. For each one, multiple subcategories are recognized.
There are also mangrove and wetland forests, as well as xerophytic scrub. According to INEGI data, 33 percent of the national surface is currently covered with forests and jungles, and 27 percent with scrubland. However, considering the potential vegetation, originally 52 percent was occupied by these habitats.
In a study published in 2021, in Nature Climate Change, it was estimated that globally in the last two decades, an average of seven thousand 600 million tons of carbon dioxide were removed from the air (net) per year in the period 2001-2019, although there is uncertainty about the exact value.
"Even though it is only an estimate, this information provides evidence that, at the end of the day, forests do contribute to significantly slowing down climate change, although deforestation in tropical countries is a strong factor, so this contribution is less than possible," says the forestry specialist.
"Another consequence of deforestation, which is not very visible but very regrettable, is the decrease in genetic diversity and ultimately the extinction of species," says Martin Ricker.
It is irreversible. There are tree species of which only a few individuals are known. Two of them that were eliminated in the wild in Mexico, but are well known because they have been cultivated as ornamental plants, are the "pita palm" (Furcraea macdougallii), which existed in Puebla and Oaxaca, and the orchid "flor de muertos" (Laelia gouldiana), native to the state of Hidalgo.
Another interesting case is Horovitzia cnidoscoloides, described in 1988 in collaboration with an IB academic, a close relative of papaya, which is only known from one place in Oaxaca and another in Belize; because of its genetic proximity to this fruit, it should be conserved.
Adequate forest management is necessary for the sustainable use of forests and to contribute to their conservation. Like forests, they are renewable resources, that is, goods can be extracted, but what is harvested must be regenerated. The culture of managing a long-term scheme is important, as well as balancing the different interests between landowners and society as a whole.
There are forests in Mexico where proper silvicultural management is implemented. However, for various reasons, most landowners seek short-term commercial use of their land.
Government reforestation programs in Mexico are focused more on providing social support than on developing these sites with a long-term vision, while the selection of species and the genetic origin of the germplasm according to the reforestation objectives, as well as the management and care for years, often do not receive the necessary attention.
To repopulate the land with plants, it is essential to find the right combination of the species with the site. In Mexico, there are approximately three thousand native trees, and although not all of them are of commercial interest, there are always some that are useful for planting. Although it is necessary to determine which one works best for the site.