Memorandum submitted by the Woodland Trust
1. The Woodland Trust welcomes the opportunity
to submit written evidence to this inquiry. The Trust is the UK's
leading woodland conservation charity. We have four main aims:
no further loss of ancient woodland, restoring and improving woodland
biodiversity, increasing new native woodland and increasing people's
understanding and enjoyment of woodland. We own over 1,000 sites
across the UK, covering around 20,000 hectares (50,000 acres)
and we have 300,000 members and supporters.
EXECUTIVE SUMMARY
2. The Woodland Trust believes land use
mechanisms will be crucial to achieving the aims of the Nitrates
Directive and believe that permanent uncultivated buffers are
an efficient and cost effective means of reducing the levels of
nitrates in waters. Such buffers should include grass, scrub and
trees as appropriate. However trees and woodlands are particularly
effective in reducing nitrates and other pollutant levels in water.
3. We provide below further evidence of
the benefits of tree and woodland buffers to water quality from
several studies as contained within research recently conducted
for the Woodland Trust.
OVERALL COMMENTS
4. Our comments focus on the costs and benefits
of the proposals for the Action Programme. They are based on the
premise that further measures are needed to reduce nitrates in
water as current measures have not had a significant impact on
nitrate pollution and nitrate pollution is increasing in some
areas.[4]
5. We welcome the strengthening of the Programme;
however we believe further measures are needed in order to meet
the aims of the Nitrates Directive and our obligations under the
Water Framework Directive.
6. We believe that land use mechanisms could
play a crucial role in achieving the aims of the Directive. Defra
proposed cover crops as a land use mechanism in the recent consultation
however we believe permanent uncultivated buffer strips adjacent
to surface water or pollution sources would be the most efficient
and cost effective way to reduce the nitrate load of waters.
7. The provision of buffer strips is provided
for under part 5 of Article 5 of the Directive. This part deals
with additional measures necessary to achieve the Directive. One
mechanism for implementation of this could be cross compliance
given that SMRs require compliance with EU Directives/Regulations.
8. Such buffer strips should include grass,
scrub and trees where appropriate. Trees and woodland are particularly
effective at reducing nitrates and other pollutant levels in water
as recent research for the Woodland Trust has shown.[5]
9. In detail: Broadleaved woodland can provide
an effective nutrient buffer for water draining adjacent land,
especially in riparian zones.[6],
[7],
[8],
[9]
It is effective at removing nitrate in drainage water, particularly
when flow is through the upper soil. For example, one study found
a 30 metre riparian woodland buffer removed nitrate to less than
detection levels in shallow groundwater by the River Garonne in
France.[10]
Another study similarly demonstrated that 99% of nitrate draining
from arable fields in southern England during winter was retained
within the first five metres of a buffer planted with poplar.[11]
Nutrient uptake is strongest during younger stages of growth and
declines rapidly with age. Riparian woodland buffers are also
effective at intercepting phosphate in drainage waters, especially
that carried by sediment.
January 2008
4 Defra (2007) The Protection of Waters Against Pollution
from Agriculture; Consultation on implementation of the Nitrates
Directive in England. Back
5
Calder, IR, Harrison, J, Nisbet, TR, and Smithers, RJ (2007) The
role of native woodland in water management (in press) Woodland
Trust. Back
6
Moore, (1999) Forests, hydrology and water quality: impacts of
silvicultural practices. University of Florida, Institute of Food
and Agricultural Sciences, pp 13. http://edis.ifas.ufl.edu/FR009#disc Back
7
Howorth, R and C Manning (2001) Land use change and the water
environment of the West Weald landscape over a 30-year period
(1971-2001). Report for Sussex Wildlife Trust and the Environment
Agency, Sussex area, 34 pages. Back
8
Puplett, D, (2003) Riparian Woodlands. Trees for Life newsletter,
Caledonia Wild! Summer 2003, http://www.treesforlife.org.uk/forest/ecological/riparianwoodland Back
9
Cook, D, T Greenaway and F Southgate (2005) Sussex Floodplain
Forest Concept Study. Report of the Record Centre Survey Unit,
139 pages. Back
10
Pinay, G, L Roques and A Fabre (1993) Spatial and Temporal Patterns
of Denitrification in a Riparian Forest. Journal of Applied Ecology,
30, issue 4, pp 581-591. Back
11
Haycock, N E and G Pinay (1993) Groundwater nitrate dynamics in
grass and poplar vegetated riparian buffer strips during the winter.
Journal of environmental quality, 22, issue 2, pp 273-278. Back
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