Comparing conifers and grazing land at Plynlimon, we found:
Forests "use" more water than short vegetation.
This is related more to the evaporation of water from the tree canopy than to difference in root depth.
There is little effect on flood flows.
Forested catchments contribute considerably more sediment to rivers than moorland areas. Suspended concentrations in the upland area are relatively low when compared to those recorded in lowland river reaches.
Some 80% of the suspended load in the forested areas, and 70% of the load in moorland areas is carried in less than 5% of the time.
Research projects have looked at the impact of forest harvesting in the instream sediment fluxes. These have contributed to the development of forestry guidelines in the UK.
The combined datasets include river flow; rainfall, cloud and stream hydro-chemistry; meteorology; and a variety of detailed spatial datasets representing the topography, soils and rivers of the catchments. This dataset is a digital river network of the natural streams and rivers within the Plynlimon catchments. An additional dataset of artificial channels also exists.
To access the datasets, please go to the CEH Environmental Information Platform and search for Plynlimon.
Links to selected related papers can be foundin the Related Links section below.