E
cosystem
servicesdelivered
Provisioning
Regulation & maintenance
Cultural
Abiotic
C
ontribution
topolicyobjectives
Water Framework Directive
Floods Directive
Birds & Habitats Directive
2020 Biodiversity Strategy
P
otential
biophysicaleffects
Runoff
Reducing pollution
Soil conservation
Habitat
Climate Change
High
Low
Medium
None
Forests often have high rates of
evapotranspiration
and canopy
interception
. Thus, headwater forest areas are able to reduce the absolute volume of water which may
eventually contribute to runoff. Moreover,
forest soils
are characterized by high porosity, high organic matter content, good infiltration capacity and high water holding ability,
enabling precipitation to be delayed on its way to generating runoff and increasing infiltration and
groundwater recharge
rates. Therefore, headwater forest catchments can
play an important role in
flood risk
reduction.
Forests are able to effectively retain atmospherically deposited
pollutants
such as nitrogen, as well as metals and organic pollutants, providing direct benefits for groundwater
chemical status. Compared to bare soils, forest cover can significantly
reduce erosion
and sediment delivery, thus contributing to improving water and habitat quality in
downstream water bodies.
Land conversion to afforest headwater catchments creates terrestrial forest
habitats
, which may have high biodiversity or recreational values, particularly when indigenous or local
species are used. Streams in forests have the potential to support diverse biological communities. Moreover, growing forests are a significant source of natural biomass production.
Depending on the rates of tree growth, headwater forest catchments can have the ability to absorb or retain CO
2,
thus offering significant
climate change
mitigation possibilities.
