Opinion Sur Joven

Green is the color we associate the most with the Earth. Maybe because it reflects the notion of life, of energy. Or because it brings jungles and forests to our minds. Or maybe because it’s more marketable than the light-brown color of drylands. However, pale yellow would be more realistic for drylands, for dying lands.

The process of desertification has been constantly growing in our global ecosystem. Although some natural phenomena erode the soil, man’s actions are by far the main causes for degradation.

The United Nations Convention to Combat Desertification (UNCCD) defines this natural disaster as the process of land degradation occurring in arid, semi-arid, dry subhumid areas. It also explains the phenomenon is due to several factors, including climate variations and human activity. The latter are addressed as “anthropic causes”.

“Desertification is a process through which the biological production of the soil gradually decreases in terms of quantity and quality as a consequence of human or climate pressure”, explained Argentine expert Jorge Morello to Opinión Sur Joven. He leads GEPAMA, the Landscape Ecology and Environment Research Team at UBA (Buenos Aires University), and he’s a researcher at the CONICET (National Council for Scientific and Technological Research).

A problem affecting millions of people

Desertification occurs in all continents, except for Antarctica. It affects millions of people’s means of living: most of them are poor. Drylands represent 41% of the Earth’s surface and host more than two billion people, one third of the human population by year 2000.

According to FAO, more than 250 million people are directly affected by desertification and about one billion inhabitants in more than 100 countries are at risk. Most of them live in the poorest and most excluded countries, where citizens are politically weak. Desertification affects a wide range of services, such as food and water. Meeting basic needs is really difficult in regions with eroded soils, which influences social indicators. According to a study by Millennium Ecosystem Assessment, these lands tend to have low per capita GDP and high infant mortality rates.

For a better understanding of this process, Morello gives an example: “If a piece of pasture is meant to receive one cow every three acres and we bring four, the soil will be saturated and the edible species of plants (called ’palatable’ plants) will gradually disappear. Before that, if we’d looked at those lands from the sky, we would have seen pastures instead of soil. After one summer of saturation, we’d see 20% of the surface; the following year, we’d see 40% of it".

Thus, desertification is no longer a problem caused by the lack of water that makes a little forest become the Sahara desert. The problem is more complex and affects different territories and populations. “Desertification used to be related to the desert or places with low rainfall. Now the process can occur even in very humid areas, such as the province of Buenos Aires (Argentina), a region where average annual rainfall is 45 inches; or in Uruguay, where hill have been filled with eucalyptuses, which absorb lots of water”, Morello.

The livestock problem

The influence of stockbreeding in the soil degradation phenomenon is deeper than we might imagine. In Morello’s opinion, “roaming cattle" is one the most damaging factors for the land. That’s why he recommends not to allow them to graze freely, but to establish delimited lots and thus let the soil rest. The same happens with goats, except for the fact that they also climb trees.

Another frequent problem is soil erosion. Morello explains: “The soil has an upper layer of decaying leaves with bugs and humus. It’s the most fertile part of it. At their best, they’re 20 inches thick. Erosion may reduce it to 8, until the second layer of the soil appears, which is almost like clay, without organic matter, and a great investment is needed to fertilize it”.

Another enemy of soil is excessive farming. On the one hand, plows used 20 years ago used to be particularly aggressive. On the other, ever-growing farming territories and consequent clearance contribute to desertification: when trees are logged, the land is left unprotected for a long period of time. “Clearance is a quasi-warlike operation: a bulldozer similar to a tank approaches the trees and uses a lever to squeeze them and a wedge to lift them off. All that material is mixed and put aside, forming a line that rots or dries out and is later burned”, Morello describes. When those remains are spread it’s like spreading ground clay: the lands will become sterile and will need to be fertilized for a long period to regenerate that fertile first layer of the soil. Forest clearance "is one of the main human activities causing desertification”, Morello emphasizes. [1]

Humans aren’t to blame for everything, but...

Although the problem is essentially anthropic, some other phenomena contribute to erosion. For instance, vulcanism tends to destroy flora and fauna with ash fall. Earthquakes and earth tremors also cause the soil on the slopes to stir, which affects that first layer as well.

Despite these phenomena, the harmful intervention of man in nature is more than clear. Two thirds of the Argentine territory are arid or semi-arid; only the Paraná-Paraguay-Plata basin maintains the richness of the fertile soil. According to Morello, the Argentine regions where the corrosive processes are more noticeable are southern Mendoza, San Juan, Catamarca, northwestern Tucumán, western Formosa and Chaco. The rest of the continent has desertification areas as well: northeastern Brazil, Uruguay and Northern Mexico are seriously affected by this problem.

When asked on concrete measures to stop this problem, Morello has no doubts: credit incentives for irrigation, delimiting of lots, cattle control and sustainable management of livestock production aimed at small farmers, as well as subsidies for sustainable forest exploitation.

Few phenomena affecting the environment are as deeply related to human activity as desertification. That makes the solution depend on us. Not only due to the way we farm, but also due to the way we vote: we must remember –even if we live in a megalopolis that covers our land with concrete and asphalt- that not so far from us a lot of people deals everyday with the problems of the earth… The dying Earth.