Some areas of land are far better suited to agriculture than others. For very fragile areas, particularly in the tropics, there may be a direct conflict between the goals of the residents and the need to preserve the soil. A family may need to collect scarce wood as the only available source of fuel, and the consequent deforestation results in national impact on food production and global impact on the environment. Protecting the environment and conserving the soil may cost the residents their livelihoods; in some areas, research which leads to a more abundant source of fuel is as critical to survival as more food.