PAGES news • Vol 18 • No 1 • April 2010
Science Highlights: Peatlands
Anshari, G., Kershaw, AP. and van der Kaars, S., 2001: A Late Pleistocene
and Holocene pollen and charcoal record from peat swamp for-
est, Lake Sentarum Wildlife Reserve, West Kalimantan, Indone-
sia, Palaeogeography, Palaeoclimatology, Palaeoecology, 171:
Page, S.E., Siegert, F., Rieley, J.O., Boehm, H.-D.V., Jaya, A. and Limin, S.,
2002: The amount of carbon released from peat and forest ﬁres in
Indonesia during 1997, Nature, 420: 61-65.
Page, S.E., Wüst, R.A.J., Weiss, D., Rieley, J.O., Shotyk, W. and Limin, S.H.,
2004: A record of Late Pleistocene and Holocene carbon accumu-
lation and climate change from an equatorial peat bog (Kaliman-
tan, Indonesia): implications for past, present and future carbon
dynamics, Journal of Quaternary Science, 19: 625-635.
Page, S.E., Rieley, J.O. and Wüst, R., 2006: Lowland tropical peatlands
of Southeast Asia. In: Martini, P., Martinez-Cortizas, A. and
Chesworth, W. (Eds) Peatlands: basin evolution and depository
of records on global environmental and climatic changes, Elsevier,
Amsterdam (D evelopments in Earth Surface Processes series),
Wüst, R.A.J. and Bustin, R.M., 2004: Late Pleistocene and Holocene
development of the interior peat-accumulating basin of tropical
Tasek Bera, Peninsular Malaysia, Palaeogeography, Palaeoclima-
tology, Palaeoecology, 211: 241-270.
For full references please consult:
Inception, history and development of peatlands in the
outi lähteenoJa1 and katherine h. roucouX2
1Department of Biology, University of Turku, Finland; outi.lahteenoja@utu.ﬁ
2School of Geography, University of Leeds, UK
The existence of peatlands in the Amazonian lowlands has only recently been confirmed, owing to the
remoteness of the area. These peatlands are important for regional carbon cycling and habitat diversity, and
represent valuable potential resources for paleoecological research.
The Amazon’s oodplain
Amazonia, the world’s largest continuous
area of humid tropical lowland rainfor-
est, is famous for its dense river network,
large seasonal variations in water level (on
average 10 m at Manaus, Brazil), and ex-
tensive oodplains and wetlands covered
by Mauritia palms, oodplain forest or sa-
vanna-like vegetation (Irmler, 1977; Junk,
1983; Junk and Piedade, 2005; Keddy et
al., 2009). Despite the great extent of wet-
lands within the Amazon Basin, the exis-
tence of tropical peatlands has rarely been
considered (but see Suszczynski, 1984;
Schulman et al., 1999; Ruokolainen et al.,
2001; Guzmán Castillo, 2007). Two stud-
ies carried out recently in Peruvian low-
land Amazonia (Loreto region, Fig. 1) by
members of the Amazon Research Team
of the University of Turku (Finland) reveal
that peat deposits, up to 6 m thick, are
widespread on oodplain wetlands of the
Western Amazon Basin (Lähteenoja et al.,
2009a, 2009b). Sixteen of seventeen stud-
ied wetland sites contained some kind of
peat deposit. According to the very rough
estimate of Schulman et al. (1999) based
on local land-cover maps, satellite images,
grey literature and sporadic eld observa-
tions, Amazonian peatlands may cover up
to 150 000 km2, an area equivalent to half
of Finland, and about 75 % of the area cov-
ered by the better-known tropical peat-
lands of Indonesia (Rieley and Page, 2005;
Page et al., this issue).
History and development
Since their late Holocene inception, the
peatlands identied in Peruvian Amazonia
have accumulated peat and carbon at rel-
atively high rates (0.94 - 4.88 mm per year,
and 26 - 195 g C m-2 per year, respectively)
(Fig. 2) and therefore constitute a strong
carbon sink (Lähteenoja et al., 2009b).
These accumulation rates are comparable
to those of the Indonesian tropical peat-
lands (Page et al., 2004) and are higher
than those of the boreal peatlands (To-
lonen and Turunen, 1996).
The basal ages of ve dated peat de-
posits varied from 0.588 cal ka BP (at 164
cm) to 2.945 cal ka BP (at 565 cm) (Lähtee-
noja et al., 2009b), which are considerably
younger than basal ages determined in
peatlands in many other regions of the
world (cf., Korhola et al., 2010). There are
several possible reasons for this. A pa-
leoecological study of lake sediments in
Peruvian Amazonia suggests that the dry
conditions of the middle Holocene were
followed by a period of increasingly wet
conditions beginning some time between
4.2 and 2.54 cal ka BP (Bush et al., 2007).
Although our oldest peat initiation dates
coincide broadly with the onset of this wet
interval, some of the peat deposits have
much younger basal ages (Lähteenoja et
al., 2009b), indicating that peat formation
was not determined purely by climate.
Peat initiation may be controlled by the
dynamic lateral migration of western
Amazonian rivers, characterized by mean-
dering and avulsion (Kalliola et al., 1992;
Neller et al., 1992; Pärssinen et al., 1996),
which have the potential to erode and
bury peat deposits. Peat accumulation
probably began when an area with water-
logged conditions was isolated from the
immediate destructive inuence of rivers.
Consequently, the Western Amazon Basin
Figure 1: The location of the study sites (from Lähteenoja et al., 2009b, Fig. 1). The map is a mosaic of histogram-
equalized Landsat TM satellite images (www.glcf.umiacs.umd.edu/). Palm swamps and forested wetlands have a
reddish tone, more or less treeless open areas (like the open peatland Riñón) are blue-green, and other ﬂoodplain
forests are pinkish to white.
PAGES news • Vol 18 • No 1 • April 2010
Science Highlights: Peatlands
may be too dynamic to allow very old peat
deposits to form (Lähteenoja et al., 2009b),
compared with, for example, those found
in the more geologically stable Indone-
sian tropical lowlands (Page et al., this is-
sue). This reasoning is supported by the
presence of several buried peat deposits
observed under the mineral subsoil of the
peatlands (Lähteenoja et al., 2009b). Older
peat deposits might well be found in geo-
logically more stable peripheral areas of
the oodplains close to the non-ooded
According to peat nutrient analyses
and topographic measurements, some of
the thickest, oldest and most stable peat-
lands have attained ombrotrophic (rain
fed) conditions, despite their location in
the middle of a oodplain environment
(Lähteenoja et al., 2009a). The sur face of
these peatlands has risen above the maxi-
mum level of river oods because of their
thick peat layer and convex topography
(Fig. 2). This change of conditions, from a
groundwater-fed system to a rain fed one,
aects the ecosystem properties in a dras-
tic way, and, consequently, the variation
of ombrotrophic bogs and minerotrophic
swamps in the Amazonian lowlands con-
tributes to the regional ecosystem diver-
sity (Fig. 3; Lähteenoja et al., 2009a).
Record of paleoclimate and
The existence of peat deposits (especially
ombrotrophic ones) within the Amazon
Basin potentially oers an excellent re-
source for studies of Holocene climate
variability, paleohydrology and rainforest
vegetation dynamics in the Amazonian
lowlands, providing histories extending
to the time of peat initiation (cf., Frost and
Miller, 1987; Ledru, 2001; Hoorn, 2006).
In a new project, due to begin in sum-
mer 2010, we will apply pollen, charcoal
and sedimentological analyses to three
of the peat sequences identied by Läh-
teenoja et al. (2009b) in order to recon-
struct changes in forest composition over
the past 3 ka, focusing in most detail on
the last 1 ka, the interval of most direct
relevance to current ecological trends.
Knowledge of tropical forest history on
this timescale is crucial to the interpreta-
tion and understanding of recent eco-
logical changes taking place in the forest
(Malhi et al., 2002). For example, studies
of a network of forest plots across Amazo-
nia (Malhi et al., 2002) show that rates of
tree mortality and recruitment (Phillips et
al., 2004), growth rates (Lewis et al., 2004)
and overall forest biomass (Baker et al.,
2004) have increased over the past three
decades. Understanding the mechanisms
behind these changes is important for
predicting their consequences for forest
biodiversity and for the role of forests in
the global carbon cycle (Cox et al., 2008).
One possible explanation is that forests
are recovering from disturbance events
prior to the start of monitoring (Wright,
2005). We intend to test this hypothesis
by applying paleoecological techniques
to the newly discovered peat sequences.
They are ideal for the purpose because: 1)
they record an interval for which there are
currently no detailed, high resolution re-
cords in this region; 2) the peat accumulat-
ed rapidly so should yield pollen records
with decadal scale temporal resolution;
and 3) they are located in a region where
forest ecology has been monitored in per-
manent census plots for the past three de-
cades (RAINFOR project: Malhi et al., 2002).
The new records will greatly improve our
understanding of the mechanisms driving
Figure 2: Peat proﬁle and accumulation rates from the San Jorge ombrotrophic bog (Loreto region, Peru). Brown
= peat, dark brown = clayey peat, gray = clay. Redrawn from Lähteenoja et al., 2009a). The core location and
peat accumulation rates (mm/a) are shown in red (from Lähteenoja et al., 2009b).
Figure 3: Four of the peatland sites indentiﬁed by Lähteenoja et al. (2009a, 2009b) in Peruvian Amazonia (Loreto): a)
Mauritia ﬂexuosa peat swamp (Quistococha), b) forested peatland (San Jorge), c) savanna-like peatland (Riñón),
d) forested peatland (Fundo Junior).
PAGES news • Vol 18 • No 1 • April 2010
Science Highlights: Peatlands
current changes in tropical forest ecology
and the sensitivity of these forests to fu-
ture climatic change.
In contrast to the Southeast Asian
tropical peatlands, these Amazonian peat-
land sites do not appear to be currently di-
rectly aected by anthropogenic actions.
Nevertheless, climate change, deforesta-
tion, large-scale land-use projects (such
as river damming, road construction and
development of oil palm plantations) and
extensive gas and oil exploration (Malhi et
al., 2008) represent an indirect threat to
the peatlands insofar as they contribute
to drying of the regional climate. Conse-
quently, there is an urgent need to inves-
tigate further, and conserve, these little-
known Amazonian ecosystems.
Guzmán Castillo, W., 2007: Valor económico del manejo sostenible de
los ecosistemas de aguaje (Mauritia ﬂexuosa). In: Feyen, J., et
al. (Eds), International Congress on Development, Environment
and Natural Resources: Multi-level and Multi-scale Sustainability,
Volume III, Publication of the Universidad Mayor San Simón, Co-
chabamba, Bolivia, 1513-1521.
Lähteenoja, O., Ruokolainen, K., Schulman, L. and Alvarez, J., 2009a:
Amazonian ﬂoodplains harbour minerotrophic and ombrotro-
phic peatlands, Catena, 79: 140-145.
Lähteenoja, O., Ruokolainen, K., Schulman, L. and Oinonen, M., 2009b:
Amazonian peatlands: an ignored C sink and potential source,
Global Change Biology, 15: 2311-2320.
Ruokolainen, K., Schulman, L. and Tuomisto, H., 2001: On Amazonian
peatlands, International Mire Conservation Group Newsletter,
Schulman, L., Ruokolainen, K. and Tuomisto, H., 1999: Parameters for
global ecosystem models, Nature, 399: 535-536.
For full references please consult:
Peatland exchanges of CO2 and CH4: The importance of
presence or absence of permafrost
torben r. chriStenSen1, m. maStepanov1, m. JohanSSon1 and d. charman2
1Department of Earth and Ecosystem Science, Lund University, Sweden; firstname.lastname@example.org
2School of Geography, University of Exeter, UK
The presence of permafrost is shown to have dramatic impacts on land-atmosphere exchanges of key
Permafrost and the carbon cycle
Permafrost, soil that stays frozen for two
or more years in a row, is a hot topic that
has attracted a lot of attention in both
the scientic and popular literature in
recent years. Permafrost underlies 25%
of the land areas in the Northern Hemi-
sphere including substantial areas with
peatlands. With a warming climate that is
particularly pronounced at high northern
latitudes, where most permafrost is pres-
ent, many questions have been raised re-
garding what may happen to peatlands
and their functioning when permafrost
thaws. In areas with infrastructure, such as
towns in northern Siberia, or oil and gas
pipelines through areas underlain by per-
mafrost, the thawing represents a serious
and possibly very expensive issue. Thaw-
ing permafrost may, however, have global
implications through changes in natural
ecosystem greenhouse-gas emissions.
Permafrost areas in the circumpolar
North are estimated to hold more than
1600 Pg of organic carbon (C) including al-
most 300 Pg in the form of peat (McGuire
et al., 2009; Tarnocai et al., 2009) most of
which has accumulated since the last gla-
cial maximum. In terms of atmospheric ex-
change of carbon, in the form of CO2 and
CH4, the potential for additional releases
are probably greater from these areas
than anywhere else in the world. While the
potential release from the huge stocks of
carbon is signicant, the actual data and
year-round monitoring of atmospheric
exchanges remain rare, and continuous
ux measurements of CO2 are limited to
a handful of sites. Continuous monitor-
ing of CH4 uxes is even rarer; the number
of operational sites is less than ve. Our
empirically based understanding of what
permafrost does to the dynamics and in-
terannual variability in atmospheric (and
dissolved run-o) uxes of organic carbon
is therefore still very poor. The longer-term
dynamics on decadal to centennial times-
cales are even less well understood.
Basic features of how ecosystems are func-
tioning with and without permafrost have
recently been discovered. At a central
Alaskan site, Schuur et al. (2009) demon-
strated that permafrost thawing is accom-
panied by respiration of previously frozen,
ancient organic carbon. In Siberian thaw
lakes, methane has been observed form-
ing from recently thawed Pleistocene or-
ganic deposits (Walter et al., 2007).
The interannual and across-site vari-
ability of CO2 exchange in continuous
permafrost ecosystems are driven pri-
marily by growing-season dynamics and
moisture conditions. Several studies have
shown that growing-season rates of CO2
uptake by these ecosystems is closely re-
Figure 1: The Zackenberg valley in NE Greenland, an area underlain by continuous permafrost. The automatic
chambers were used for the studies of methane emission dynamics during freeze-in (Mastepanov et al., 2008).
Local inhabitants, the muskoxen, are present in the background. Photo by C. Sigsgaard, from Christensen et al.,
2009, reprinted with permission.
O. Lähteenoja and K.H. Roucoux
Baker, T.R., et al., 2004: Variation in wood density determines spatial patterns in Amazonian
forest biomass, Global Change Biology, 10: 545-562.
Bush, M.B., Silman, M.R. and Listopad, M.C.S., 2007: A regional study of Holocene climate
change and human occupation in Peruvian Amazonia, Journal of Biogeography, 34(8):
Cox, P.M., Harris, P.P., Huntingford, C., Betts, R.A., Collins, M., Jones, C.D., Jupp, T.E.,
Marengo, J.A. and Nobre, C.A., 2008: Increasing risk of Amazonian drought due to
decreasing aerosol pollution, Nature, 453: 212-215.
Frost, I.G. and Miller, M.C., 1987: Late Holocene flooding in the Ecuadorian rainforest,
Freshwater Biology 18(3): 443-453.
Guzmán Castillo, W., 2007: Valor económico del manejo sostenible de los ecosistemas de
aguaje (Mauritia flexuosa). In: Feyen, J., et al. (Eds), International Congress on
Development, Environment and Natural Resources: Multi-level and Multi-scale
Sustainability, Volume III, Publication of the Universidad Mayor San Simón,
Cochabamba, Bolivia, 1513-1521.
Hoorn, C., 2006: Mangrove Forests and Marine Incursions in Neogene Amazonia (Lower
Apaporis River, Colombia), Palaios, 21: 197-209.
Irmler, U., 1977: Inundation – forest types in the vicinity of Manaus, Biogeographica 8: 17-
Junk, W.J., 1983: Ecology of swamps on the middle Amazon. In: Gore, A.J.P. (Ed), Mires:
swamp, bog, fen and moor, regional studies; ecosystems of the World 4B, Elsevier,
Amsterdam, The Netherlands, 269-294.
Junk, W.J. and Piedade, M.T.F., 2005: The Amazon River basin. In: Fraser, L.H., et al. (Eds),
The World’s Largest Wetlands: Ecology and Conservation, Cambridge University Press,
Kalliola, R., Salo, J., Puhakka, M., Rajasilta, M., Häme, T., Neller, R.J., Räsänen, M.E. and
Danjoy, Arias W.A., 1992: Upper Amazon channel migration: Implications for
vegetation perturbance and succession using bitemporal Landsat MSS images,
Naturwissenschaften, 79: 75-79.
Keddy, P.A., Fraser, L.H., Solomeshch, A.I., Junk, W.J., Campbell, D.R., Arroyo, M.T.K.
and Alho, C.J.R., 2009: Wet and Wonderful: The World's Largest Wetlands Are
Conservation Priorities, BioScience, 59(1): 39-51.
Korhola, A., Ruppel, M., Seppä, H., Väliranta, M., Virtanen, T. and Weckström, J., in press:
The importance of northern peatland expansion to the late-Holocene rise of atmospheric
methane, Quaternary Science Reviews, 29(5-6): 611-617.
Lähteenoja, O., Ruokolainen, K., Schulman, L. and Alvarez, J., 2009a: Amazonian
floodplains harbour minerotrophic and ombrotrophic peatlands, Catena, 79: 140-145.
Lähteenoja, O., Ruokolainen, K., Schulman, L. and Oinonen, M., 2009b: Amazonian
peatlands: an ignored C sink and potential source, Global Change Biology, 15: 2311-
Ledru, M.P., 2001: Late Holocene rainforest disturbance in French Guiana, Review of
Palaeobotany and Palynology, 115: 161-170.
Lewis, S.L., et al., 2004: Are global change agents causing widespread changes in tropical
forest dynamics? Evidence from 50 South American long-term monitoring plots,
Philosophical Transactions of the Royal Society of London, Series B, 359: 421-436.
Malhi, Y., et al., 2002: An international network to understand the biomass and dynamics of
Amazonian forests (RAINFOR), Journal of Vegetation Science, 13: 439-450.
Malhi, Y., Roberts, J.T., Betts, R.A., Killeen, T.J., Li, W. and Noble, C.A., 2008: Climate
Change, Deforestation and the Fate of the Amazon, Science, 319: 169-172.
Neller, R.J., Salo, J.S. and Räsänen, M.E., 1992: On the formation of blocked valley lakes by
channel avulsion in Upper Amazon foreland basins, Zeitschrift für Geomorphologie,
Page, S.E., Wüst, R.A.J., Weiss, D., Rieley, J.O., Shotyk, W. and Limin, S.H., 2004: A record
of Late Pleistocene and Holocene carbon accumulation and climate change from an
equatorial peat bog (Kalimantan, Indonesia): implications for past, present and future
carbon dynamics, Journal of Quaternary Science, 19: 625-635.
Page, S.E., Wüst R.A.J. and Banks, C., 2010: Past and present carbon accumulation and loss
in Southeast Asian peatlands, PAGES news, 18(1).
Pärssinen, M.H., Salo, J.S. and Räsänen, M.E., 1996: River floodplain relocations and the
abandonment of aborigine settlements in the Upper Amazon Basin: a historical case
study of San Miguel de Cunibos at the Middle Ucayali River, Geoarchaeology: An
International Journal, 11(4): 345-359.
Phillips, O., Baker, T.R., Arroyo, L., Higuchi, N., Killeen, T., Laurance, W.F., Lewis, S.L.,
Lloyd, J., Malhi, Y. and Monteagudo, A., 2004: Pattern and process in Amazon tree
turnover, 1976-2001, Philosophical Transactions of the Royal Society of London, Series
B, 359: 381-407.
Rieley, J.O. and Page, S.E., 2005: Wise use of tropical peatlands: Focus on Southeast Asia.
Alterra - Wageningen University and Research Center and the EU INCO-STRAPEAT
and RESTORPEAT Partnerships: 168.
Ruokolainen, K., Schulman, L. and Tuomisto, H., 2001: On Amazonian peatlands,
International Mire Conservation Group Newsletter, 2001(4): 8-10.
Schulman, L., Ruokolainen, K. and Tuomisto, H., 1999: Parameters for global ecosystem
models, Nature, 399: 535-536.
Suszczynski, E., 1984: The peat resources of Brazil. Proceedings of the 7th International
Peat Congress, Dublin 1: 468-492.
Tolonen, K. and Turunen, J., 1996: Accumulation rates of carbon in mires in Finland and
implications for climate change, The Holocene, 6(2): 171-178.
Wright, S.J., 2005: Tropical forests in a changing environment, Trends in Ecology &
Evolution, 20(10): 553-560.