Riparian
PROGRAMME · RIVER & LAKE BUFFERS
Multi-species tree belts along river banks and lake edges — willow at the water line, poplar and birch above. Roots stabilise banks, intercept agricultural runoff, and create fish habitat.
Why this programme exists
Mongolia's river banks lose vegetation cover to overgrazing and flood events, leading to bank erosion, sediment-loaded rivers, and loss of cold-water fish habitat. Riparian forest buffers are the single highest-impact restoration intervention per metre planted — root systems hold the bank, canopy shades the water, and the buffer filters agricultural N runoff before it reaches the river.
How it works
- 1
Bank survey + flood-line mapping
Identify erosion-active bank sections within 30m of the water line. Avoid sensitive spawning beds.
- 2
Two-zone planting
Zone 1 (water edge, 0-3m): willow + sea buckthorn — fibrous root mat for bank-toe stabilisation. Zone 2 (3-30m): poplar + birch — deeper canopy for shading + N filtration.
- 3
Linear spacing
1.5m along the bank, 3m between rows. Stagger species so the buffer functions even if individual trees fail.
- 4
3-year care
Y1 watering only in extreme dry years (willow tolerates a lot). Fencing protecting young trees from grazing. No herbicide.
- 5
Y3 bank position survey
GPS bank-position survey + N-filtration measurement to confirm the buffer is doing its job, not just present.
Where we plant
- Selenge (basin-wide)
- Khentii (Onon + Kherlen)
- Uvs (lake basin)
- Khövsgöl
Measured impact
- 100m bank planted stabilises
- ~1,500 m² riparian zone
- Agricultural N runoff filtered
- ~80% (vs. unplanted control)
- Bank erosion rate
- 5-10× slower than bare control