Without the tree roots that anchors the soil, it results in top soil erosion which leads to problems such as increased flooding and decline in crop yield. The run-off into rivers from soil erosion results in siltation entering lakes, streams and rivers. This in turn creates significant problems, such as:
- Decreased quality of local water supplies, leading to lower standard of living of the local community
- Increased Flooding, affecting agricultural yield
- Decrease in productivity of Hydroelectric Projects, reducing the supply of energy
- Rising of riverbeds, which heighten the severity of flooding, affecting local fisheries as the sediments leads to lower hatch rates
- Social, economic and environmental problems in affected areas
On top of that, the slash and burn practices by Indonesian farmers exacerbate soil erosion as the cash crops planted in place of the trees cannot hold onto the soil the way trees’ can.
Source: http://indianapublicmedia.org/eartheats/government-underestimating-farmland-erosion/