Agriculture Reference
In-Depth Information
S.F.I.Haslamet al.
C Dynamics in Upland Soils after Serious Fires
4.15
Carbon Dynamics in Upland
Soils after Serious Fires
S.F.I. H ASLAM 1,2 , D.W. H OPKINS 3
AND J.A. C HUDEK 4
1
Department of Biological Sciences, University of Dundee,
Dundee DD1 4HN; 3 Department of Environmental Science,
University of Stirling, Stirling FK9 4LA; and 4 Department of
Chemistry, University of Dundee, Dundee DD1 4HN, UK.
2
Present address: Scottish Environmental Protection Agency,
GraesserHouse,FoddertyWay, Dingwall, Ross-shire IV15 9XB,
UK
Introduction
The estimated global C loss from terrestrial sources to the atmosphere due
to fire is 4 g C year −1 (Andreae, 1991), but this ignores the C loss from soils
(Kasischke et al ., 1995). The upland soils of the temperate and circum-
boreal regions contain a vast amount of organic matter because the cool,
wet and often acidic soil conditions restrict the rate of decomposition, with
the result that organic matter accumulates at the soil surface (Floate, 1977).
Such soils are a globally important reservoir of organic C (Post et al ., 1985;
Eswaran et al ., 1993; Howard et al ., 1995) and fires are not uncommon in
upland areas. Natural vegetation fires are caused predominantly by light-
ning strikes (Billings, 1964), but in upland areas they are usually the result
of human activity. Humans have used fire since stone age times to fashion
the landscape, and this has contributed both to the decline of woodland and
the maintenance of heath and grass moorland (Tinsley, 1975). In modern
times, managed burning is usually restricted to combustion of dry and
senescent plant material leaving a layer of ash which is followed by relatively
rapid regrowth of the plants with increased vigour (Grant, 1968), and
it is thus widely adopted in upland management (Kenworthy, 1963;
Gimingham, 1972). Managed burning also reduces the probability of
catastrophic fires by removing much of the fuel (Miller et al ., 1984). Serious
fires occur either completely by accident or when vegetation burning gets
out of control, and these can lead to substantial, if localized, loss of soil
organic matter either directly by combustion or as a result of erosion from
the dried and exposed soil surface. Occasionally, such serious fires lead to
 
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