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Moorland Indicators of Climate Change (MICCI) 2012
This is the 5th year that local secondary school students have been out during National Science and
Engineering week to explore UK moorlands and carry out environmental surveys in National Parks.
Under the guidance of the Peak District National Park Learning Team, led by Chris Robinson, 14
schools from across the UK took part in an initiative to connect people with moorlands and
investigate their effect on climate change.
Peat moorlands are an internationally important resource, providing environmental, economic and
social benefits including: carbon storage and sequestration; water regulation; biodiversity
protection; natural risk mitigation and recreation opportunities, amongst others. These products and
services are ’freely’ provided by functioning moorlands however are costly to replace once
ecosystems are degraded or lost.
As large volumes of dead and decaying organic matter, peatlands are a globally important landbased carbon store, holding carbon that could otherwise be released into the environment in other
forms and exacerbate global climate change. UK peatlands are currently the UK’s largest terrestrial
carbon sink so it is important that we are able to identify when and how they are changing.
This year, as part of the Moorland Indicators of Climate Change initiative (MICCI) 14 schools
collected environmental data across 13 sites in England (8 in the Peak District), Wales (4) and
Scotland (1 in Cairngorm) over 4 days between the 9th and 15th of March. This data included
information about the site (altitude), its hydrology (water table height and river water pH), soils (pH,
soil surface water pH, temperature, organic content, moisture content and peat depth) and
vegetation.
From this data we can calculate how much carbon peat soils contain and how much is being lost to
the environment. We can also investigate how these carbon content measures relate to other
aspects of the moorland ecosystem as well as how these indicators interact with each-other.
How much carbon does peat contain?
Peat soils are made up of decaying plant and animal matter and so have a high soil organic matter
(SOM) content which effectively makes them an important carbon store. To investigate how much
carbon our peat soils contain (which could otherwise be lost to the environment) we can calculate
the carbon content of small soil samples that were collected using the equation below.
SOCs = SOCc × BD × LD ×102 (t ha-1)
where
SOCS: total amount of soil organic carbon to given depth (t ha-1)
SOCC: soil organic carbon content for given depth (%)
BD: dry bulk density (g cm-3)
LD: Depth of soil layer (m)
http://eusoils.jrc.ec.europa.eu/ESDB_Archive/eusoils_docs/Other/EUR25225.pdf
Table 1: Calculating the total amount of soil carbon in a given depth of peat at our sample sites.
Site Name
Mean peat depth
(m)
Wessenden
Snake Summit
Upper Burbage
Cowper Stone
Derbyshire bridge
Harland brook
Averhill
0.64
2.38
1.97
1.51
0.58
0.2
0.64
Soil organic
content (%)
Bulk
Density
-3
(g/cm ) *
52.75
99.7
87.46
86.75
28
91
91
0.12
0.12
0.12
0.12
0.12
0.12
0.12
Total amount of soil
carbon to a given depth
-3
(t ha )
402.35
2848.93
2065.59
1573.21
194.99
221.13
698.88
*Bulk density values estimated from Lindsay 2010 Peatbogs and Carbon: A critical synthesis
(http://www.rspb.org.uk/Images/Peatbogs_and_carbon_tcm9-255200.pdf). If peat < 0.15m deep = an
estimated dry bulk density of 0.06 g cm-3, > 0.15m deep = 0.12 g cm-3
Figure 1: Total amount of soil carbon to a given depth (tonnes per hectare) calculated for 7 sites in the Peak District
Total amount of soil
carbon to
a given depth (t/ha)
3000
2500
2000
1500
1000
500
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Based on the measurements that schools provided, the total amount of soil carbon contained at the
given depth of each site varied from 194.99 (Derbyshire Bridge) – 2848.93 (Snake summit) tonnes
per hectare, which even from these rough calculations, suggests that although peat sites within the
Peak District differ significantly in the amount of carbon they store, there are areas that are very
carbon rich on a national and global scale (see figure 2).
Soil Organic Carbon (SOC) content has been estimated across the globe on a relatively coarse scale.
Surveying the amount of organic carbon in our soils on a small scale, as MICCI did this year, we can
monitor changes in soil organic carbon over time and in relation to environmental changes.
1
2
Figure 2: Estimated Peaty Soil Carbon content of the UK and a Global Carbon Map
1
2
Natural England: NE257 England’s peatlands http://publications.naturalengland.org.uk/publication/30021 (UNEP-WCMC)
http://eusoils.jrc.ec.europa.eu/ESDB_Archive/octop/Global.html
How much carbon is being lost?
The carbon balance of peatlands is very delicate and depends mainly on the water table. In healthy
blanket bogs, the water table should be close to the surface to maintain active sequestration (carbon
sink). If the water table drops then air gets into the peat and decomposition starts, changing the
peat into a source of carbon.
One of the major routes of carbon loss from peatland is in water flowing downstream. By measuring
the total organic carbon (TOC) in streams we can get an indication of the amount of carbon, bound
in an organic compound, being lost from peat. TOC also acts as a non-specific indicator of water
quality and is used by water companies during the purification of drinking water.
TOC values recorded during the MICCI project this year ranged from 42.42 mg/l (Wessenden) to
164.6 mg/l (Upper Burbage), both of which are in the Peak District. Soils with higher moisture
content had higher TOC values associated with them (see figure 3). Whilst this suggests that water
flowing from wetter peat soils release more carbon than drier soils, there are many other
environmental factors, such as the height of the water table, recent weather events and the
condition of the peat (i.e. intact, degraded or recently restored) that could explain this, which is why
it is important for us to investigate as many of these factors as we can before we make any
conclusions.
Figure 3 & 4: TOC levels are higher at sites with higher moisture content (r = 0.82, p <0.05, N= 8 ); Water flowing from soils
with a higher moisture content were also significantly more acidic.
(r = -0.82, p <0.01, N = 9).
Water flowing from soils with a higher moisture content were significantly more acidic. As peaty
soils (which are acidic) tend to be waterlogged, with a high moisture content, it makes sense that the
longer water stays in peaty soils, and the more contact they have, the more acidic water draining
from soils with a high moisture content may be. This could also be a result of the type of water
entering the soil as oppose to the condition of the peat. In ombrotrophic systems water entering the
soil is rainwater. These soils tend to be more acidic than those in minerotrophic systems where
water has been in contact with mineral soils (which are less acidic than peat) before it reaches the
bog. Unfortunately we didn’t have enough results from the wet pH flush samples to compare with
the surface water samples, which would have allowed us to compare pH differences between these
systems.
Water tables fluctuate over the year. However, a functioning blanket bog should be
waterlogged for much of the year or have a water table just below the surface. Although we didn’t
find a correlation between peat depth and water table level in this year’s results, sites with deeper
peat soils did have higher moisture contents than shallower soils (see figure 5).
Figure 5: Deeper peat soils had a higher moisture content (r =0.81, p<0.05, N=8).
High water tables prevent the peat from decomposing. The optimum moisture content for of
functioning blanket bog (where high water table levels maintain anaerobic conditions ideal for peat
formation) is 50 – 70%, any less and the peat starts to decompose, producing carbon dioxide (CO2),
any more and it produces methane (CH4), both of which change it from a carbon sink to a source.
Unfortunately 8 out of 10 of the UK sites had a soil moisture content above or below this optimum
limit. Finding out whether the peat has the correct saturation of water, helps inform conservation
work. Restoration of water tables through gully blocking, ditch blocking and re-vegetation of bare
peat, can promote peat formation, therefore actively combat climate change.
Other Moorland Indicators of climate change: Vegetation
Differences in vegetation communities can be due to climate, soil condition, air pollution, and
hydrology as well as the interaction between these factors. By monitoring changes in vegetation,
along with as many of these key indicators as possible, we can begin to assess the impact of climate
and land use change on moorland vegetation over time.
Table 2: Proportion of each species recorded in moorland
vegetation samples March 2012
Species
Heather
Bilberry
Crowberry
N-L grass
B-L grass
Star Moss
Sphagnum Moss
Cotton Sedge
Sorrel
Rushes
Tormentil
Others
UK
<1
<1
19
15
11
17
10
2
15
<1
6
5
Peak District
<1
<1
22
14
14
13
12
<1
15
0
3
7
Wales
1
1
14
14
5
26
6
7
16
<1
9
1
Cairngorm
0
0
0
46
0
24
0
0
0
0
30
0
There is no clear pattern of vegetation change at sites that have been surveyed by MICCI over the
last 5 years. This doesn’t necessarily mean that there hasn’t been a change in vegetation
communities, it may be that the any changes have been too small for us to detect yet and that
patterns will emerge over the next few years.
By continuing to measure these environmental indicators year after year at the same sites in the
same way they can provide valuable information on how moorlands and their management
contribute to and are effected by climate change.
Outcomes
It has been another successful year for MICCI. Together with the schools that took part we have
continued to promote the need to protect the natural resources (such as water, soil and air quality)
of moorlands in UK National Parks whilst providing learning opportunities to key rural and urban
audiences, particularly young people, from surrounding urban areas.
With thanks to all the schools and students that took part. The Economic and Social Research
Council provided a grant so that this could be included in the Festival of Social Science/ National
Science and Engineering week in March 2009 and 2010. OPAL and the East Midlands branch of
the British Association of Science provided some funding for 2011. In 2012 OPAL and South West
Water through the Exmoor Mires Project are helping to fund MICCI. Dr Martin Evans of Manchester
University kindly provided TOC analysis. Moors for the future collated and analysed results.
References:
Hiederer, R. and M. Köchy1 (2011) Global Soil Organic Carbon Estimates and the
Harmonized World Soil Database. EUR 25225 EN. Publications Office of the European Union.79pp.
http://eusoils.jrc.ec.europa.eu/ESDB_Archive/octop/Global.html
Lindsay, R. (2010) Peatbogs and Carbon: A critical synthesis
(http://www.rspb.org.uk/Images/Peatbogs_and_carbon_tcm9-255200.pdf
Natural England: NE257 England’s peatlands
http://publications.naturalengland.org.uk/publication/30021