1.

Typical surface fire in a dry dipterocarp forest, Thailand.

Photo: GFMC (K. Wanthongchai)

The role and history of fire

in tropical landscapes
Johann Georg Goldammer

Introduction
Globally, most landscape fires occur in the tropics and subtropics, where
natural, lightning-caused fires have favoured the evolution of characteristic
plant communities in sustainable fire ecosystems. Indigenous communities
“Fire management solutions and developed traditional burning practices for land management, especially
decision making must be based in fire-adapted and fire-dependent tropical savannas and deciduous
on historic and contemporary forests. Traditional small-scale slash-and-burn agriculture is still practised
scientific-technical evidence.” in fire-sensitive ecosystems such as equatorial rainforests, peatlands and
wetlands.

Fire is also increasingly used for large-scale conversion to agro-industrial

plantations and grazing land, and this, as well as maintenance burning
of newly created open landscapes — such as recurrent use of fire in cattle
pastures or for removal of agricultural residues — is a major source of
uncontrolled wildfires. These often spread to surrounding land, including

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fire-sensitive forests and protected areas, leading to severe regions where rural populations and especially youth
degradation of ecosystems and loss of forest cover. are urbanizing, there is underutilized or abandoned
land subject to plant encroachment and ecological
The characteristics, impacts and severity of fires vary, succession, where invasion of flammable secondary and
depending on land use, intensity of utilization and seasonally vegetation leads to increasing wildfire hazard
associated degradation. For example, secondary and risk.
vegetation on degraded tropical forest lands, such as the
vast areas of Imperata grasslands (Imperata cylindrica in While landscapes and fire regimes — the typical
Southeast Asia and Imperata brasiliensis in South America) occurrence of fire in an ecosystem as characterized by
that are highly flammable and where frequent — often seasonality, return intervals, behaviour and severity —
annual — wildfires occur. In conjunction with increasingly vary over regions and time, there are historical constants.
extended droughts due to climate change, these Fires have affected the vegetation of the planet for more
landscapes suffer excessive burning, degradation and than 400 million years, long before the advent of humans.
loss of vegetation cover. Besides the direct effects of fire on ecosystems, fire-
generated emissions are part of global biogeochemical
Intensive agricultural and grazing systems result in the cycles and have always influenced the chemistry of
fragmentation of tropical and subtropical landscapes. the atmosphere. In the 1980s, interactions between fire,
Rural communities and individual farmers and tropical forests, savanna, climate and climate change
pastoralists have a high interest in protecting their land, arose as a major focus of interdisciplinary research
villages and other assets against the adverse effects (Goldammer 1990; Crutzen and Goldammer 1993;
of wildfires, and where the safe use of fire and wildfire Goldammer 2013); see Figure 1.
prevention measures often results in a significant
decrease in the number of wildfires and area burned. In

Climate Climate change

Microclimate feedback
Dynamic equilibrium

Greenhouse gases

Stress, trauma
Droughts

Climate- Fire frequency

Supported Land use
Fire Savanna
Tropical
Selection of
Forest pyroxerophytic
vegetation

Figure 1. Interactions between fire, tropical vegetation and climate, developed at the first global forum on the role of fire in
the tropics and its global implications. Source: Goldammer (1990)

History of fire in the tropics During the Pleistocene, the role and influence of fire
on vegetation may have changed in accordance with
Charcoal fragments in coal seams (fusain) provide climatic fluctuations. During interglacial periods, the
evidence of fire in ancient forests from the Carboniferous prevailing warmer and more humid climate created
Period. Radiometric age determination of charcoal found conditions that were unfavourable for fire. During glacial
in Amazon rainforests reveals prehistoric natural or early- epochs that occurred for some 80% of the last two
human-caused fires in the Holocene (ca. 3500–6000 million years, the tropical climate was cooler, more arid
years BP). In Southeast Asia, charcoal samples from and seasonal than at present. This caused rainforests
lowland rainforests in eastern Borneo were dated to the to retreat into refugia, surrounded by savanna-type
peak of the last Pleistocene glaciation, ca. 18,000 years BP vegetation that was likely to have been strongly
(Goldammer and Seibert 1990).
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 —  The role and history of fire in tropical landscapes —

influenced by fire. Such fire “corridors” between refugia element in the development of tropical vegetation and a
may have contributed significantly to the genetic isolation predominant driver of degradation and destruction.
of present-day rainforest “islands.”
Tropical fire regimes
In Africa, early humans used fire for at least 1.5 million
years, and this spread globally, becoming a dominant Fire regimes in tropical forests and derived vegetation
factor that especially influenced tropical vegetation, are characterized and distinguished by fire frequency,
as shown by pollen analysis. In seasonally dry regions seasonality and behaviour (intensity/severity). Tropical
adjoining humid equatorial rainforests, fires were set for and subtropical fire regimes (Figure 2) are determined by
hunting, to improve grazing, and to keep land open for ecological and anthropogenic (socio-cultural) gradients.
security (improved visibility) and accessibility. Neolithic Lightning is also an important cause of natural fires,
fires played a role in opening closed forest ecosystems which influenced savanna-type vegetation in pre-
and savannization, and the reasons for and methods settlement periods, and are observed in deciduous and
of fire use have changed little since then. Today, semi-deciduous forests and occasionally in rainforests.
however, unprecedented human population pressure,
However, with increasing human activities, the
consequences of climate change, and changing fire
contribution of natural ignition to overall tropical fire
regimes mean that the influence of fire is now a critical
occurrence is becoming less significant, compared to

Figure 2. Types of tropical/subtropical fire regimes, related to ecological and anthropogenic gradients. Note: there are
exemptions to this generalized scheme, such as higher species diversity in certain fire climax communities.
Source: Goldammer (1993)

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Effects of a forest-conversion fire after clearing a lowland dipterocarp forest in East Kalimantan, Indonesia. Photo: GFMC

human-caused ignitions or fires purposely set for the Fire in equatorial rainforests
following main reasons (see also Goldammer and de
These are fire-sensitive ecosystems, where the main issue
Ronde 2004).
is the use of fire for forest clearing:
• the most convenient and inexpensive tool for
• slash-and-burn agriculture, where small forest
converting forest and other native vegetation
areas are temporarily converted to agricultural use
(including wetlands and peatlands) to other land
before being allowed to return to forest vegetation
uses; e.g., agriculture, plantations and pasture,
after a relatively short period; and
or exploiting other natural resources (open-cast
• conversion to plantations, cropland and pastures
mining);
(or other non-forestry land uses), where large forest
• traditional slash-and-burn agriculture;
areas are permanently changed.
• grazing land and pasture management; i.e., fires
set by hunters and herders, mainly in savannas Clearing and burning always follow the same pattern.
and open forests, and by managers of industrial Trees are felled at the end of the wet season, and to
livestock enterprises; improve burning efficiency, vegetation is left for some
• harvest of non-timber forest products; i.e., the use weeks to dry out. In undisturbed rainforests, the efficiency
of fire to facilitate harvesting or improve yields of of the first burning varies and may not exceed 10–-30%
plants, fruits, etc., predominantly in deciduous and of aboveground biomass, as only a small amount of the
semi-deciduous forests; biomass in the tree trunks is consumed. The remainder is
• fires that start at the interface of residential areas; treated by a second fire or is left at the site to decompose.
• traditional fire uses such as religious, ethnic and
folk practices; and Slash-and-burn farming provided a sustainable system
• targeted or collateral consequences of conflicts for indigenous forest inhabitants, and the patchy impacts
over land-use rights or territorial sovereignty. had limited effects on the overall tropical forest biome.
Today, it is still practised in many topical regions, but is
The following sections discuss the role and history of fire in becoming increasingly destructive because of population
five generic forest types: equatorial rainforests, seasonal pressures, which lead to larger cleared areas and shorter
forests, tropical highland and subtropical lowland pine fallow (forest recovery) periods. In addition, large areas of
forests, savannas and open woodlands and planted primary and secondary rainforest are increasingly being
forests. converted for plantations, agriculture and grazing land
in many regions of the tropics (Page et al. 2013; Cochrane
2013).

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Targeted fire use in rainforests often results in wildfires Forest regeneration after fire shows no coherent pattern.
that escape control. The impact of drought and fire on Although dipterocarp forests tend to be highly fire-
Borneo and the Amazon rainforests since the 1980s show sensitive, there is regeneration potential where burning
that undisturbed vegetation may become flammable. is moderate. However, recurring fires in rainforests lead
Cases of rainforest fires associated with droughts were to degradation over time by successively reducing forest
reported in Borneo in the 1800s and 1900s, and during cover and species diversity, and finally, with the invasion of
the 1982–83 drought, numerous fires spread beyond pyrophytic grasses. Large tracts of former tropical lowland
forest conversion and shifting agriculture areas, affecting rainforests are now degraded Imperata grasslands,
approximately 5 million ha in East Kalimantan, Indonesia, maintained by fires with a short return interval.
and the Malaysian provinces of Sabah and Sarawak
(Goldammer and Seibert 1990). The 1997–98 fires in Fire in seasonal forests
Southeast Asia resulted in a total burned area of 5 million The occurrence of seasonal dry periods in the tropics
ha in East Kalimantan, including 2.6 million ha of forest increases with distance from the equatorial zone.
that burned with varying degrees of damage (Heil and Rainforests gradually transition to open, semi-deciduous
Goldammer 2001; and Siegert et al. 2001). and deciduous monsoon, moist and dry forests. Between

(a) (b) (c)

(d) (e) (f)

Fire-induced destruction of a lowland tropical rainforest in East Kalimantan, Indonesia.

(a) Pristine dipterocarp rainforest (1980); (b) surface fire following selective logging (1982); (c) post-fire stage with some trees still standing (1985);
(d) post-fire stage after more trees have died and undergrowth now dominated by pioneer species, highly flammable in extremely dry years (1995);
(e) after a second, high-intensity fire (1998); and (f) final stage of savannization, and invasion by Imperata cylindrica (1998, on a frequently burned
site nearby). Source: Goldammer et al. (1996) and Goldammer (1999). Photos: GFMC

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Left: Typical pure stands of fire-resistant sal (Shorea robusta); and right: teak (Tectona grandis) in northern India that result from fires
occurring every 1 to 3 years, eliminating competing tree species. Photos: GFMC

more closed deciduous forests and grass savannas, although isolated crowns may burn earlier in the dry
a broad range of ecotones are found. As varied season before leaves are shed. In some cases, fires may
terminology is used to describe non-evergreen forests occur in the same area several times per year; e.g., an
and transitions to savannas, the prevailing fuel type is early dry season fire that consumes the grass layer, and a
more appropriate for distinguishing diverse formations subsequent fire that burns shed leaf litter.
(Goldammer 1991, 1993).
The ecological impacts of annual fires on deciduous
The term “forest” is used where trees and woody and semi-deciduous forests are significant. Fire strongly
matter dominate the fuel mix. The main fire-related favours fire-tolerant tree species, which replace other
characteristics of forests are seasonally available species that would grow in an undisturbed environment.
flammable fuels (grass-herb layers and shed leaves), For example, many monsoon forests in continental
which allow the understorey (grass and shrub layers) Southeast Asia would return to evergreen rainforest if
and overstorey (tree layer) to survive and even take human-caused fires were eliminated. This effect has
advantage of the regular influence of fire. Adaptive traits also been observed in Australia when aboriginal fire
include thick bark, ability to heal (fire scars), resprouting practices and fire regimes were controlled, and rainforest
capability (coppicing, epicormic sprouts, dormant buds, vegetation started to replace fire-prone tree-grass
and lignotubers), and seed characteristics (serotiny, savannas.
or seed release after fire, dispersal, dormancy, etc.)
(Stott et al. 1990; Goldammer 1993). These features are Tropical deciduous forests largely constitute a “fire
characteristic elements of a fire ecosystem. climax”; i.e., their composition and dynamics are
predominantly shaped by fire. However, they are not
Deciduous trees shed their leaves during the dry season, necessarily ecologically stable, as the long-term impacts
creating an annual source of surface fuel. In addition, of frequent fires lead to considerable site degradation. For
the layer of drying and dried grass, together with the instance, erosion tends to be significant due to depletion
shrub layer, add to the available fuel, which generally of the protective litter layer by fire just before the onset
ranges between 5 and 10 tonnes/ha. Herders, hunters and of monsoon rains. In India, fire adaptations and the fire
collectors of non-timber forest products usually set fires dependency of economically important trees such as sal
to burn the forest floor to remove dead plant material, (Shorea robusta) and teak (Tectona grandis) have been the
stimulate grass growth, and facilitate or improve the focus of discussions regarding fire control policy since the
harvest of forest products. Fires usually develop as colonial period.
moderately intense surface fires and can spread over
large areas. The canopy layer is generally not affected,

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Fire in tropical highland and subtropical lowland from the subtropical coastal area along the Gulf of
pine forests Mexico into southern temperate forest regions. Pines that
may dominate or form pure stands are in permanent
Of the more than 100 species of pines, some extend into
competition with more fire-sensitive broadleaved trees.
the tropics, but none occur naturally in tropical Africa or in
Pines gained a competitive advantage with regular
the whole of the southern hemisphere (except Sumatra).
natural lightning-caused fires, and with historic fires set
Tropical pines are largely confined to lower montane
by the pre-Columbian population and later by European
rainforest zones, usually on dry sites with a seasonal
colonists. This fire regime was disturbed, however, by
climate. Most are pioneers and tend to occupy disturbed
the influential European dogma of fire exclusion, which
sites such as landslides, abandoned lands and burned
was inappropriately imposed on North America in the
sites. In the subtropics, pines are also found in lowlands.
late 1800s, and on many other areas in the world. In the
1970s, US public policies were further modified, this time
Most tropical pines show distinct adaptations to fire,
aiming to re-establish natural and human-shaped fire
with thick bark, taproots, some sprouting post-fire, and
regimes through the reintroduction of prescribed burning
highly flammable litter. Tropical fire-climax pine forests,
practices, and by allowing some wildfires to burn within
largely the result of a long history of regular burning, are
fire management objectives.
found throughout Central America, at mid-elevations of
the southern Himalayas, and in submontane elevations
In tropical and subtropical regions, fire-climax pine forests
throughout much of Southeast Asia. As in tropical
can support large human populations. If managed
deciduous forests, fires are generally started by herders,
properly, fire creates highly productive forests that can
hunters and collectors, but they also spread from the
provide sustained supplies of timber, fuelwood, resin and
careless use of fire in farmland. The increased frequency
grazing. However, the increasing occurrence of wildfires —
of human-caused fires has led to an overall increase of
coupled with overgrazing and excessive logging — tends
fire-adapted pines and pure pine stands outside their
to destabilize submontane pine forests, resulting in forest
natural area of occurrence in a non-fire environment. In
depletion, erosion and subsequent flooding of downslope
tropical montane zones, fire also leads to an increase in
catchments.
altitudinal distribution, expanding mid-elevation pine
forest belts into lowland rainforests and higher-altitude Fire in savannas and open woodlands
broadleaved forests.
The various types of natural savannas are shaped by
Subtropical fire-climax pine forests are also the result their edaphic, climatic and orographic origins and
of a long history of natural and anthropogenic fires. by wildlife (grazing, browsing and trampling) and
In North America, the belt of southern pines stretches fire (Cole 1986). Alongside anthropogenic influences

Left: A young Pinus khesyia stand on a steep slope in Luzón, the Philippines. Right: an open stand of Pinus roxburghii on the
Himalayan slopes in Uttar Pradesh, India. Large tracts of such pine forest are subject to severe erosion due to the effects of regular
fires and overgrazing. Photos: GFMC

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such as livestock grazing and harvesting of fuelwood throughout history are significant in the development of
and non-timber products, most tropical savannas are tropical savannas, and modern analyses have always
also affected by regularly occurring human-made fires regarded the role of fire as especially important.
(Figure 3). The interactions of wildlife, humans and fire

Figure 3. Generalized scheme of closed dry deciduous forest degradation and rehabilitation, as induced by uncontrolled
fire and grazing (regressive) and protective measures (progressive). Adapted from Verma (1972)

Many tropical humid savannas are stable fire climax ecosystems, such as humid Guinean savannas in Côte d’Ivoire that are subject
to regular fires. The extreme fire tolerance of palms (here: Borassus aethiopum) is a pantropical phenomenon. Photo: GFMC

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 —  The role and history of fire in tropical landscapes —

Left: A typical fuel load of needles in a 9-year-old Pinus ellliottii plantation in Brazil, with a “ladder” of aerial fuels and a lack of
understorey. Right: Surface fuel load in a 15-year-old Pinus taeda plantation after the third thinning. Photos: GFMC

Concerning fire ecology, the distinction between pine and eucalyptus). Litter production in plantations
savannas and open forests can be based on potential of fast-growing species is extremely high, and with the
fuel availability. In grass savannas, the grass layer is the exclusion of other forest uses leads to an accumulation of
exclusive or predominant fuel, whereas in open deciduous surface fuels (thick layers of needles/leaves, woody debris,
forests the predominant fuel is tree leaf litter and woody shed bark) and aerial fuels (shed needles, leaves and
material from the tree layer. In open savanna woodlands twigs that are caught in branches).
(tree savannas), grass is also an important surface fuel.
Within their natural range, both pine and eucalyptus
Fuel availability varies with the various bioclimatic and have developed forest formations that are largely shaped
phytogeographic savanna zones (Menaut et al. 1991). In by natural and human-made fires. Regularly occurring
the arid West African Sahel, aboveground biomass is 0.5– fires suppress fire-sensitive vegetation and favour the
2.5 t/ha, increasing to 2–4 t/ha in the mesic Sudan zone, formation of pure stands. Exclusion of fire from these fire-
and up to 8 t/ha in the humid Guinea zone. Fire frequency climax ecosystems generally leads to a build-up of fuels
largely depends on fuel continuity and density. Thus, and an extreme wildfire hazard, where high-intensity fires
savannas with relatively high and continuous loads of are likely. Similarly, they were established as plantations
flammable grasses, such as those in the Guinea zone, are without considering or introducing recurrent fire as a
subject to shorter fire-return intervals than arid savannas. basic element to stabilize the biological disequilibrium in
In addition, burning efficiency depends on the moisture fuel dynamics. Consequently, many of these plantations
content of dead and live organic matter, so fires in the are also highly susceptible to high-intensity fires.
early dry season generally consume less aboveground
biomass than those at the end of the dry season. The introduction of prescribed fire into tropical
plantations, or the reintroduction of fire into fire
Fires in planted forests ecosystems where fire-free management systems have
been applied, remains a necessary but challenging field
Forest plantations in the tropics are established for three
of practice and requires changes in fire management
main purposes: (i) to support the demands of local
policy (Goldammer and de Ronde 2004).
people for timber, fuelwood, non-timber forest products,
etc., (ii) for landscape rehabilitation or environmental
protection; e.g., greenbelts, shelterbelts, erosion control Conclusions
and sand stabilization; and (iii) to establish industrial Globally, the role of natural fire in ecosystems, and of
monoculture plantations for timber, pulpwood or cultural fire in land management, has been explored
oilseeds, almost entirely with exotic species (commonly, widely. This article provides an overview of the many roles

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and impacts and roles of fire in different environments Goldammer JG. ed. 1992. Tropical forests in transition. Ecology of
in and around tropical forests, and while not exhaustive, natural and anthropogenic disturbance processes: An introduction. In
Goldammer JG. ed. Advances in Life Sciences. Birkhäuser, Basel. https://
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Goldammer JG. ed. 1990. Fire in the tropical biota: Ecosystem processes
scientific and technical evidence. and global challenges. Ecological Studies Series Vol. 84. Springer, Berlin.
https://link.springer.com/book/10.1007/978-3-642-75395-4.
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the application of fire management approaches in which handbook for sub-Sahara Africa. Global Fire Management Center,
local communities act in their own interest to maximize Freiburg, Germany, and Oneworldbooks, Cape Town, South Africa.
the benefits from the appropriate use of fire and to avoid https://gfmc.online/latestnews/GFMC-Wildland-Fire-Management-
damage caused by wildfires. Unfortunately, only a few Handbook-Sub-Sahara-Africa-2004.pdf.
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76:518–520. https://doi.org/10.1007/BF00374124.
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Goldammer JG, Seibert B and Schindele W. 1996. Fire in dipterocarp
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ecosystems: Towards sustainable management. Singapore: World
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Author affiliations
Johann Georg Goldammer, Director, Global Fire Monitoring Center (GFMC), Max Planck Institute for Chemistry and Freiburg
University, Freiburg, Germany (fire@fire.uni-freiburg.de)

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