Tree Roots

The powerful stabilising effects of a trees roots is widely known but often poorly implemented in Uganda as incorrect species are selected that either cannot withstand the frequent flood events or who are so thirsty themselves that they disrupt the water table (and yes, we are looking at you eucalyptus).

Farmers who have land adjacent to rivers or streams either have fantastic years due to the fertility of their soils or terrible years because the water levels rise so high in flash flood events that they lose their entire harvest. The planting of trees along a riverbank helps to mitigate such events and improve recovery times following heavy rains. The trees themselves slow down the rate at which rainfall and surface runoff enter the rivers which decreases the flooding risk. In the same way that a swamp can act like a sponge to slow the rate at which water enters a river, so do the canopies of trees as the water must pass through layers of leaves, each slowing the rate at which water is entering the river.

Benefits of Trees for River Systems

Countries throughout the world are at last starting to realise the benefits of using natural resources such as planting trees alongside riverbanks to mitigate against potential flood problems but this is only one of the roles they play.

• Trees absorb many toxins from the water which improves water quality, benefiting both communities dependent on it and fish and other organisms living in it.
• Riparian forest buffers filter sediment from streams during storm events.
• Reduce nitrogen and phosphorous leaching from adjacent land that may come from agriculture.
• Provide stability to the bank through extensive root network.
• Shade and modify stream temperatures, critical for habitat and pollution reduction.
• Provide aquatic and wildlife habitat for many species.
• Reduce stream velocity and reduce downstream flooding.
• Additionally, as long as coppice-capable species have been selected, they can also regularly be harvested for poles or firewood.

It’s this extensive list of benefits that means indigenous tree reintroduction into local land management practices is unobtainable without successful partnerships with farmers and the local communities who live alongside waterways. We hope to achieve this by tailoring our programs specifically to the needs of each individual farmer or community and to develop long-standing relationships to ensure durability of the interventions.