Economic and Social Causes of Deforestation

Social Causes: Population Pressure and Subsistence Farming

• Not everyone cutting down trees is doing it to get rich; many are simply trying to survive.
• Population pressure occurs when the number of people exceeds the environment's capacity to support them. In the 1960s and 70s, the Brazilian government encouraged over 1 million "landless poor" to move from overcrowded cities into the Amazon.
• These settlers rely on subsistence farming, growing only enough food to feed their families with no surplus for trade. This accounts for roughly 25% of Amazonian deforestation.
• Subsistence farmers often use a "slash-and-burn" cycle, burning vegetation to create fertile ash. However, tropical soils (called latosols) are nutrient-poor because deforestation breaks the natural nutrient cycling process.
• The soil becomes infertile after just 3–5 years. This forces farmers to abandon their plots and clear more "virgin" primary forest to survive.

The Multiplier Effect: Infrastructure and Settlement Expansion

• The paving of a single road can trigger a chain reaction that destroys thousands of square kilometres of natural habitat.
• Infrastructure development (the construction of physical structures like roads and dams) physically connects economic and social drivers. The Trans-Amazonian Highway, spanning over 4,000km, was the primary catalyst for opening up the Amazon interior.
• A staggering 95% of all deforestation in the Amazon occurs within 50km of a road or navigable river.
• This infrastructure directly facilitates settlement expansion (the growth of urban areas and housing). For instance, the town of Parauapebas grew from 154,000 to 220,000 people in just two years to support the workforce of the Carajás mine.

Analyzing the Chain of Reasoning:

1. Social/Economic Demand: Global demand for timber and local demand for space triggers road building.
2. Infrastructure: Roads penetrate the primary forest.
3. Economic Access: Loggers extract valuable timber; ranchers follow to clear the remaining degraded forest for cattle.
4. Social Settlement: Subsistence farmers use the smaller branching roads to clear "fishbone" patterns of land for crops.

Analyzing Causes in UK Deciduous Woodlands

• Deforestation isn't just a tropical issue; the woodlands on your doorstep are also shrinking due to unique social and economic pressures.
• Unlike the Amazon, where vast regions are cleared for new land, UK woodland loss is usually characterised by fragmentation (breaking woods into smaller, less healthy pieces). Roughly 7% of ancient woodland has been lost to agricultural expansion in the last 100 years.
• Transport infrastructure is the most significant modern threat. High Speed 2 (HS2) dissects over 100 ancient woodlands, with Phase One causing the direct loss of up to 20.6 hectares across 25 sites (e.g., Jones’ Hill Wood).
• To mitigate this, developers sometimes attempt translocation—the experimental process of moving ancient woodland soil and saplings to a new site—but this is highly controversial and often unsuccessful.
• Socially, a growing UK population drives the need for 300,000 new homes annually, placing immense pressure on Greenfield sites (land that has never been built on).
• Economically, native broadleaf trees are sometimes substituted with fast-growing coniferous monocultures (like Sitka Spruce). While economically profitable for timber, these plantations are ecologically "dead" because their dense canopies completely block light from reaching the forest floor.