Slash-and-burn agriculture can be a sound agricultural practice in many instances and has long been practised by many aboriginal communities. Although the jury is still out on how sustainable this practice is, many believe that small scale practice of slash and burn can actually be beneficial to the soil and biodiversity.

Slash-and-burn agriculture is responsible for the loss of around 50 acres of land every hour worldwide. One of the issues with slash and burn is that fires intentionally set can unintentionally spread throughout the forest. When fire spreads to unintended areas, the protective forest canopy is destroyed. The resulting sun exposure to the forest floor intensifies the existing fire. The smoke than “hangs over the forest, and suppresses rainfall,” making it even more difficult to extinguish as the area becomes drier.

For example, in the Amazon rainforest the seasons are so extreme, in terms of precipitation, that there are just two named seasons: “wet” and “dry.” During the dry season, the problems with slash-and-burn agriculture are intensified. Although there are many, complex issues surrounding the use of slash-and-burn agriculture in the Amazon, the underlying rationale for the practice is very simple: the soil in the Amazon rainforest is infertile, much to the dismay of the estimated 250 million farmers working the poor soil of the tropical forests there. For impoverished farmers, the simplest solution to this problem is to cut down the trees, and burn what remains. This makes the soil more fertile as incinerated biomass provides nitrogen and other nourishing nutrients for the soil.

Unfortunately, this is a short term solution. The soil only stays nutrient-rich for so long, about two years, after this time, the nutrients from the burned biomass are used up. When this happens, farmers pack up and move on to the next section of the rainforest, leaving their farmland behind for others to use for cattle rearing or abandonment.

Furthermore, slash-and-burn agriculture on this scale can also have devastating effects on the biodiversity in the area. With large areas of land being incinerated, many animal habitats are lost in the fire. This pushes animals out of the forest, decreasing biodiversity, and increasing the number of endangered and extinct animal species.

The next problem is cattle ranching which has a massive impact on forests around the world, particularly tropical rainforests like the Amazon. Many farmers use deforested areas of land to raise cattle; however, it might surprise you to learn that corporations do this on a much larger scale. Fast food companies have been contributing to deforestation in places like the Amazon rainforest for quite some time, and only in relatively recent years have their actions been acknowledged by mainstream media. Companies that have been deforesting the rainforest in order to raise cattle for their hamburgers include Wal-mart, McDonald's, Pizza Hut, and Burger King, just to name a few. Although some of these companies have made promises to be more environmentally conscious, some, such as Burger King and Pizza Hut, have made no plans to move away from this harmful and unnecessary form of animal agriculture.

Logging is also a common cause of deforestation as trees are cut down to use for paper products. There are several different types of logging: however, the most harmful one is called “clear cutting.” This is when an area of forest is wholly deforested, leaving no trees alive in that area.