Presentation by Mike Billet at VNN peatland workshop, Leeds 18th January 2012

1. Peatland Management Impacts
on Water Quality and Biodiversity
Mike Billett/Chris Evans
Centre for Ecology & Hydrology
Edinburgh/Bangor
VNN Peatlands Workshop Leeds 18 Jan 2012

2. Peatland management issues
Estimated that 18% of UK peatlands are
in natural or near-natural condition
remaining affected by change to
agricultural land use (40%), severe erosion
(16%), peat cutting (11%) and
de/afforestation (10%).
AMS source with 134 graphite
target locations
Littlewood, N. et al. (2010). Peatland biodiversity. Report to IUCN UK Peatland Programme

3. Potential water quality issues
•Solutes
•Particulates
•Dissolved gases
•Organic compounds
•Inorganic compounds
•Concentrations
•Fluxes
•Simple dilution/concentration effects
•Pollutant retention/release (≈ peatland condition)
•Timing of transport (“the hydrochemical response”)

4. Peatland management – effect of burning
• Correlative study suggesting higher DOC
loss in recently burnt areas
• For peat catchments stopping burning in
the Peak District would reduce DOC by
~40%
• On the same basis increasing burning on
the Migneint to Peak District levels would
increase DOC by ~30% Yallop and Clutterbuck, 2009.
• This is controversial! Experimental data Science of the Total
from burnt areas at Moor House (Ward et Environment
al., 2007; Worrall and Adamson, 2007) did
not show the same DOC response

5. Peatland management – effect of grazing
• Limited data available
• Available evidence suggests little impact of moderate grazing
on DOC, acidity.
• Overgrazing of peatlands may lead to erosion associated with
increased nitrate and POC losses
• Overall, current evidence considered insufficient to make
predictions of change

6. Peatland management – effect of drainage
• Evidence limited and rather
inconclusive
• Wallage et al. study suggests
potential for ~25% reduction
in DOC with drain-blocking
Wallage et al., 2006. Science of the
Total Environment

7. Peatland restoration - catchment scale research
Drained N
Forested 70
Felled
Gaseous C
Sampling 60 DIC
Downstream Export (g C m-2 yr-1)
location
DOC
50
POC
40
30
20
10
Drains
blocked
0
Pristine Drain Blocked Drained
2 km
•Flow Country peatland catchment – initial results suggest
higher C fluxes (2006-08) from the drain blocked and drained
site compared to pristine
•Importance of long-term studies
•Also evidence that gully blocking may increase DOC loss
(Daniels et al., 2008. Science of the Total Environment )

8. Peatland restoration - catchment scale research
Burning stopped Grazing removed
Gullies blocked
20 2002-03
2003-04
18 2004-05
Areal Export of DOC (Ctkm yr )
-1 2005-06
-2
16
14
12
10
8
6
4
2
0
Within Clough Nether Gate Doctors Gate Upper North Upper Gate Red Clough
Clough Clough Grain Clough
TREATMENT CONTROL
Treatments began in 2003 on several Peak district catchments
•some early evidence that gully blocking may be reducing
the DOC flux?
•Importance of long-term studies
O’Brien et al. 2008

9. Particulate organic carbon (POC)
Evans et al. (2005): Re-vegetation Catchment Area POC flux Reference Notes
Upper North Grain 0.38 km2 95.7 g C m-2 y-1 Evans et al. (2006) Severe gully
reduces sediment production and erosion
slope-channel linkages Upper North Grain 0.85 km2 74.0 g C m-2 y-1 Pawson et al. Severe gully
(Snake Pass) (2008) erosion
Holden et al. (2007): At least 50 times Torside Clough 3.31 km2 11.3 g C m-2 y-1 Rothwell (2006) Calculated
more sediment from open compared from data in
Rothwell
to blocked drains (2006) based
on 70%
organic
content)
Unnamed micro- 0.0007 km2 92.5 g C m-2 y-1 MG Evans Bare peat
catchment near unpublished data catchment
Bleaklow summit
Unnamed micro- 0.005 km2 3.4 g C m-2 y-1 MG Evans Uneroded
catchment near unpublished data catchment
Snake summit
Lady Clough 1.33 km2 44.8 g C m-2 y-1 Pawson (2008)
Measured particulate organic carbon
(POC) fluxes from Bleaklow Plateau
catchments
Billett et al. 2010

10. Rough Sike story (Moor House NNR)
Crisp 1966: Input and output of minerals for an area of Pennine moorland: the
importance of precipitation, drainage, peat erosion and animals
In 1962-63 Crisp estimated the loss of 5 elements
(tonnes yr-1) down Rough Sike
Na 3.76
K 0.74 55 g C m-2 yr-1
Ca 4.46
P 0.03
N 0.24
C 46.0* (*assumes peat contains 50% C)
Equivalent to peat loss of 1 cm yr-1 from actively eroding areas (10-20% of catchment)
-------------------------------------------------------------------------------------------------------------------------
Evans & Warburton 2005: Sediment budget of an eroding peat-moorland catchment in
northern England
•In 1997-2001 estimated that 37 tonnes yr-1 of sediment were lost down Rough Sike
(≈19 tonnes C)
•Significant evidence of re-vegetation since the 1960s
Crisp 1966 J. Ecology
Evans & Warburton 2005 ESPL

11. Biodiversity and peatland management
Probability of occurrence of ‘positive’ and ‘negative’ indicator species on peatland as a
function of wetness and vegetation height based on Countryside Survey data
MultiMOVE model, courtesy of Ed Rowe, Peter Henrys and Simon Smart
(other input parameters including pH, nitrogen and climate set to typical blanket bog conditions)

12. Research evidence base: summary
With the exception of sediment yield and POC, the evidence
is patchy and at times contradictory
Scale is hugely important
Are catchment studies of peatland management effects always
going to be too site specific and short-term?
Should we focus more on process understanding rather than
downstream effects?
Understanding of effects on biodiversity is poor, although clear
links between hydrology and plant species/functional group
DOC
Effect of drain blocking……..
Time