Land degradation: Role of deforestation

Forests are invaluable to humans, both for us to live and to keep our economy going. Look around your room. I bet you can name more than 10 things in your room that is directly, or indirectly obtained from a forest.

But here’s the paradox: while we need standing forests to live, we need to cut down forests to pursue our economic and agricultural activities. In the last 10,000 years, we have chosen the latter. By clearing away forests, we hit two birds with one stone: acquire land for humans to inhibit, and get produce to fuel the economy.

The Roman Empire, Harappan civilization, Ancient Greece were all destroyed because those lands were intensely deforested and the land couldn’t deal with the pressure humans put on it.

In the last 10,000 years, the forest cover in the world has fallen by 50%! Of this, most of the deforestation has occurred in the last 100 years. The sharp rise in deforestation has been supplemented by a growing world economy and booming population. Here are some of the stats from the most affected parts of the world-

Why are we doing this?

Deforestation is being done for a variety of activities.

• Agriculture has been the biggest reason for deforestation throughout history. Since the time agriculture started, humans have largely depended on cutting down forests or parts of forests to grow their crops.
• Increasing population has required us to acquire land to live on. Forests have been the first victim. We have cleared forest land to create spaces for human settlement throughout history (generally coupled with agriculture). In recent years, deforestation has been directly proportional to urbanisation.
• Forest lands have also been cleared to create pastures for cattle and other grazers. While this was not a huge activity in the past, in the last century or so the meat industry has grown manifold. Many parts of the Amazon forest has been cleared solely to create pastures to feed meat-producing animals.
• Other economical activities have required us to clear forests. Wood, which is essential for so many things in our daily life, comes only after we cut down a tree. Similarly, large developmental projects like setting up industries, power plants, mining activities require us to clear the forest as well.

This has caused a lot of problems…

While deforestation has resulted in many ecological problems like habitat loss, mass extinction, increased CO2 emissions, etc., I will specifically focus on the changes it has brought to land and land processes.

• Deforestation has a direct link to soil erosion. Trees have large root systems. The roots can typically span more area under the ground than they do above the ground. The roots are like fingers stretching deep into the Earth. And like fingers, they grip the soil they penetrate. This makes the soil immune to getting washed away during rains, heavy winds or floods. Forests actively prevent soil erosion, which has been considered the biggest caused of land degradation. Madagascar, for example, loses so much soil to erosion (400 tons/ha) that its rivers run blood-red, staining the surrounding Indian Ocean. Madagascar is actually called the Great Red Island.
• Forests have an active relationship with the land they live in. They form part of one of the most important processes in the ecosystem: nutrient cycling. Trees take up nutrients from the soil for their physiological processes. On the other land, when leaves fall off or when a plant dies, the nutrients are leached back into the soil. If forests disappear, this process in that area is shattered. Nutrients are leached deep into the ground as water infiltrates the soil, or it is washed away as the soil is eroded.
• Forests also play a huge role in recharging groundwater. This is the largest source of freshwater available for humans. Trees in the forest hold up flowing water, allowing it to slowly infiltrate into the soil. When forests disappear, the water table falls lower and lower into the ground and the soils become very salty.
• The activities that directly depend on forests cannot be sustained. Large populations of people who depend on these activities for their survival will become “deforested refugees”.
• A freshly deforested land presents a huge number of opportunities. We can grow crops, mine, build settlements, etc. But this land is cursed. After a few years, the very land that was a treasure trove will become an evil trap. None of those activities can be sustained forever on a land that is not being recharged of those invaluable properties forest lands have.
• Deforestation in extreme cases have lead to complete desertification of the land. A once fertile area supporting a thriving forest ecosystem turns into nothing but desert land. This has been a major cause of fall of great civilizations throughout history. The Roman Empire, Harappan civilization, Ancient Greece were all destroyed because those lands were intensely deforested and the land couldn’t deal with the pressure humans put on it. Today, the Sahara Desert is expanding south at the rate of 48 kilometers per year! Don’t believe me? Look at the map above.

By choosing economy over life, we have chosen a path that will take us high into the sky, that might bring us crashing down. That’s what happened to the civilizations of Rome, Harappa, and Greece. That’s what happened in Eater Islands as well. However, those civilizations were wiped out locally. In today’s interconnected world, every activity we pursue will have implications that reach far off places. If a civilization falls this time, it’ll be the entire human civilization all over the world.