The problem we treat is erosion, with resulting soil infertility/lost wildlife and ecosystem services/rural poverty/displacement to slums/and even illegal immigration.
Rainforests are logged worldwide for their valuable timber. Logging is driven by complex factors. Two examples are subsidies by governments in tropical countries for slum dwellers and farmers to clear and settle forest land, and consumer demand in industrialized countries for tropical products like hardwoods, railroad ties, beef and palm oil.
Roads into pristine forest do much damage and open the rainforest for settlers to follow. Settlers try to make a living from newly opened forest land but, surprisingly, soils in the rainy tropics are inherently poor.
Over millennia, heavy rains have leached their nutrients away. The trees themselves capture what nutrients they can from decomposing leaves on the forest floor, but nutrients are lost when the logs are exported, slash is burned, the forest floor is opened to sun and rain, and erosion ensues. These subsidized farmers are often doomed to fail.
Unsustainability of Tropical Agriculture
It is not easy to farm these soils sustainably. Thin tropical topsoils exposed to heavy rains erode rapidlly, carrying away what nutrients they contained and exposing even more infertile sub-soils. Expensive fertilizer application is required increasingly over time but much is lost to the same heavy rains that take away topsoil.
Pasture is often the end use of damaged lands
because some kinds of grasses are able to grow in exposed sub-soils. But
when the land is overstocked and overgrazed, cattle track the hillsides deeply, resulting in
chutes of water during torrential rains that can carve enormous gullies. The deeper the cow paths erode, the poorer the soil and the less productive the earth. Unsecured by tree roots, entire hillsides can slump and become treacherous and unusable.
Consequences to the People and Land
The economic and ecological losses do not stop there. Run-off from erosion clogs watercourses with sediments and chemicals, contaminating drinking water and killing fish, clams, and crayfish that used to provide protein to the people. These losses together with progressively reduced crop productivity can lead to entrenched poverty among farmers. Farmers then must clear more land from marginal patches of forest that still remain, or migrate to cities and slums or, illegally, to industrialized nations.
Even though now abandoned, these lands may be so degraded that forest cannot recover by the natural processes of regeneration. Worse, nature has lost its ability to provide ecosystem goods and services, such as protein sources from fish and wildlife, pure drinking water and fertile soil, to the human community at large. Beyond a point, nature cannot heal itself in economically viable timescales without human intervention.
Thus, there are many consequences to people as a result of deforestation that affects ecosystem goods and services. We have seen many of these tragic consequences firsthand in Costa Rica.