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[Gene GeRue <genegerue AT ruralize.com>]

This makes me rethink the demise of the dinos. Nah, probably a comet or a 
volcano.


To: "Gene GeRue" <genegerue AT ruralize.com> Subject: The Overstory 
#161--Forest fire and biological diversity
The Overstory #161--Forest fire and biological diversity
By R. Nasi, R. Dennis, E. Meijaard, G. Applegate and P. Moore
Publication date: September 26, 2005

::::::::::::::

The Overstory Book, 2nd Edition, a formatted, indexed and illustrated
compilation of The Overstory ejournal editions 1 - 138 is in stock.
Your purchase helps support publication of The Overstory:
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The Overstory #161--Forest fire and biological diversity
By R. Nasi, R. Dennis, E. Meijaard, G. Applegate and P. Moore

Contents:
: INTRODUCTION
: ECOSYSTEM EFFECTS OF FIRE
: IMPACTS OF HUMAN-INDUCED OR SEVERE NATURAL WILDFIRE ON PLANT DIVERSITY
: NATURAL FIRE REGIMES AND FIRE-ADAPTED PLANT SPECIES
: EFFECTS OF FIRE ON FOREST FAUNA
: --> Loss of habitat, territories and shelter
: --> Loss of food
: --> Fire-adapted fauna
: EFFECTS OF SUPPRESSION OF THE NATURAL FIRE REGIME
: REFERENCES
: ORIGINAL SOURCE
: ABOUT THE AUTHORS
: RELATED EDITIONS OF THE OVERSTORY
: PUBLISHER NOTES
: SUBSCRIPTIONS

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INTRODUCTION
Fire is a vital and natural part of the functioning of numerous forest
ecosystems. Humans have used fire for thousands of years as a land
management tool. Fire is one of the natural forces that has influenced
plant communities over time and as a natural process it serves an
important function in maintaining the health of certain ecosystems.
However, in the latter part of the twentieth century, changes in the
human-fire dynamic and an increase in El Niño frequency have led to a
situation where fires are now a major threat to many forests and the
biodiversity therein. Tropical rain forests and cloud forests, which
typically do not burn on a large scale, were devastated by wildfires
during the 1980s and 1990s (FAO, 2001).
Although the ecological impact of fires on forest ecosystems has been
investigated across boreal, temperate and tropical biomes, comparatively
little attention has been paid to the impact of fires on forest
biodiversity, especially for the tropics. For example, of the 36
donor-assisted fire projects carried out or ongoing in Indonesia, a
megadiversity country, between 1983 and 1998, only one specifically
addressed the impact on biodiversity.

ECOSYSTEM EFFECTS OF FIRE
Forest fires have many implications for biological diversity. At the
global scale, they are a significant source of emitted carbon,
contributing to global warming which could lead to biodiversity changes.
At the regional and local level, they lead to change in biomass stocks,
alter the hydrological cycle with subsequent effects for marine systems
such as coral reefs, and impact plant and animal species' functioning.
Smoke from fires can significantly reduce photosynthetic activity
(Davies and Unam, 1999) and can be detrimental to health of humans and
animals.
One of the most important ecological effects of burning is the increased
probability of further burning in subsequent years, as dead trees topple
to the ground, opening up the forest to drying by sunlight, and building
up the fuel load with an increase in fire-prone species, such as
pyrophytic grasses. The consequence of repeated burns is detrimental
because it is a key factor in the impoverishment of biodiversity in rain
forest ecosystems. Fires can be followed by insect colonization and
infestation which disturb the ecological balance.
The replacement of vast areas of forest with pyrophytic grasslands is
one of the most negative ecological impacts of fires in tropical rain
forests. These processes have already been observed in parts of
Indonesia and Amazonia (Turvey, 1994; Cochrane et al., 1999; Nepstad,
Moreira and Alencar, 1999). What was once a dense evergreen forest
becomes an impoverished forest populated by a few fire-resistant tree
species and a ground cover of weedy grasses (Cochrane et al., 1999). In
North Queensland in Australia, it has been observed that where the
aboriginal fire practices and fire regimes were controlled, rain forest
vegetation started to replace the fire-prone tree-grass savannahs
(Stocker, 1981).

IMPACTS OF HUMAN-INDUCED OR SEVERE NATURAL WILDFIRE ON PLANT DIVERSITY
Wildfire is unusual in most undisturbed, tall, closed-canopy, tropical
rain forests because of the moist microclimate, moist fuels, low wind
speeds and high rainfall. However, rain forests may become more
susceptible to fire during severe droughts, as experienced during El
Niño years. In these forests which are not adapted to fire, fire can
kill virtually all seedlings, sprouts, lianas and young trees because
they are not protected by thick bark. Damage to the seed bank, seedlings
and saplings hinders recovery of the original species (Woods, 1989). The
degree of recovery and need for rehabilitation interventions depends on
the intensity of burning (Schindele, Thoma and Panzer, 1989).
Tropical forests are also subject to fires started by humans for
agricultural clearing. Deforestation fires, which are more common in
disturbed forests, can vary in intensity and burn standing trees, at the
worst completely burning the forest leaving nothing but bare soil.
There is some concern that salvage logging (removal of dead timber from
severely burned logged-over forest or burned primary forest), used as a
management and financing tool after fires in Indonesia in 1997-1998, may
adversely affect the course of vegetation succession (van Nieuwstadt,
Sheil and Kartawinata, 2001).
Although fire is a frequent natural disturbance in boreal forests and
they usually regenerate easily after fire, frequent high-intensity fires
can offset this balance. As a result of extremely severe fires in the
Russian Federation in 1998, more than 2 million hectares of forest have
lost most of their major ecological functions for a period of 50 to 100
years (Shvidenko and Goldammer, 2001). Severe fires have had a
significant negative impact on plant diversity. Southern species that
are at the northern edge of their geographic range are particularly
vulnerable. For example, in Primorsky Kray (Russian Federation),
human-induced fires have contributed to drastic reductions in the
populations of 60 species of vascular plants, ten fungi, eight lichens
and six species of mosses during the past two or three decades
(Shvidenko and Goldammer, 2001).

NATURAL FIRE REGIMES AND FIRE-ADAPTED PLANT SPECIES
In tropical forests where fires occur every dry season (savannah
woodlands, monsoon forests and tropical pine forests), tree species
exhibit adaptive traits such as thick bark, ability to heal fire scars,
resprouting capability and seed adaptations. The ecological importance
of these annual fires on forest formations is significant. Fire strongly
promotes fire-tolerant species, which replace the species potentially
growing in an undisturbed environment.
Fires are a natural and important disturbance in many temperate forests,
and this is seen in plant adaptations such as thick bark, which enables
a species to withstand or resist recurrent low intensity fires, while
less well-adapted associates perish. Some tree species in North America,
notably Jack pine (Pinus banksiana) and lodgepole pine (Pinus contorta),
have serotinous (late-opening) cones. While closed, these cones hold a
viable seed bank in the canopy that remains protected until fire affects
the tree. After fire, the cone scales open, releasing the seed into a
freshly prepared ash bed. Many plant species have the ability to
resprout after being burned, either from the rootstock or the stem
(Agee, 1993). Mountain ash (Eucalyptus regnans), a eucalypt of temperate
Australia, also requires a site to burn completely and be exposed to
full sun for the species to regenerate prolifically (IUCN/WWF, 2000).
Forest flammability is high in the Mediterranean Basin and most plant
communities are fire prone. Quercus ilex is resistant to mild fires, and
woodlands recover without any major floral or structural change (Trabaud
and Lepart 1980). If fire is neither frequent nor intense, open cork oak
(Quercus suber) forests can persist.
Fire, often with high intensity, is the major natural disturbance
mechanism in boreal forests. Fire return times (the average interval of
time between two fires in the same place in one ecosystem) in natural
forests vary greatly, from as little as 40 years (in some Jack pine
[Pinus banksiana] ecosystems in central Canada) to as long as 300 years
depending on climate patterns (van Wagner, 1978). In Sweden, it has been
estimated that about 1 percent of the forest land burned yearly before
systematic suppression of fires started in the late nineteenth century
(Zackrisson, 1977). Most boreal conifers and broad-leaved deciduous
trees suffer high mortality even at low fire intensities owing to canopy
architecture, low foliar moisture and thin bark (Johnson, 1992). Some
North American pines (Pinus banksiana, P. resinosa, P. monticola) and
European pines (P. sylvestris) have thicker bark and generally greater
crown base and height, and old tall trees can often survive several
fires. The disturbance regime of fire creates succession patterns which
cause the mosaic of age classes and communities. Fire refuges exist in
some parts of the forest on moist sites with local humidity, where fire
may be absent for several hundred years. Fire refuges are vital to the
forest ecosystem in the boreal region because many species can survive
only in such areas, and then supply a seed source to recolonize the
burned areas (Ohlson et al., 1997).
In the natural forests of the northern and sparsely stocked taiga and
forest tundra, particularly on permafrost sites, surface fires occurring
at long-return intervals of 80 to 100 years represent a natural
mechanism that prevents the transformation of forests to shrubland or
grassland (Shvidenko and Goldammer, 2001).

EFFECTS OF FIRE ON FOREST FAUNA
In forests where fire is not a natural disturbance, it can have
devastating impacts on forest vertebrates and invertebrates - not only
killing them directly, but also leading to longer-term indirect effects
such as stress and loss of habitat, territories, shelter and food. The
loss of key organisms in forest ecosystems, such as invertebrates,
pollinators and decomposers, can significantly slow the recovery rate of
the forest (Boer, 1989).
Estimates from the 1998 fires in the Russian Federation suggest that
mammals and fish were badly affected. Mortality of squirrels and
weasels, estimated immediately after the fires, reached 70 to 80
percent; boar 15 to 25 percent; and rodents 90 percent (Shvidenko and
Goldammer, 2001).

--> Loss of habitat, territories and shelter
The destruction of standing cavity trees as well as dead logs on the
ground has negative effects on most small mammal species (e.g. tarsiers,
bats and lemurs) and cavity-nesting birds (Kinnaird and O'Brien, 1998).
Fires can cause the displacement of territorial birds and mammals, which
may upset the local balance and ultimately result in the loss of
wildlife, since displaced individuals have nowhere to go. The severe
fires of 1998 in the Russian Federation led to increased water
temperatures and high carbon dioxide levels in lakes and waterways,
which adversely affected salmon spawning (Shvidenko and Goldammer,
2001). In areas where frequent burning occurs on a broad scale,
preserving a range of microhabitats can make a substantial contribution
to conserving biodiversity (Andrew, Rodgerson and York, 2000).

--> Loss of food
Loss of fruit-trees results in overall decline in bird and animal
species that rely on fruits for food; this effect is particularly
pronounced in tropical forests. A few months after the 1982-1983 fires
in Kutai National Park, East Kalimantan, fruit-eating birds such as
hornbills declined dramatically, and only insectivorous birds such as
woodpeckers were common because of the abundance of wood-eating insects.
Burned forests become impoverished of small mammals, birds and reptiles,
and carnivores tend to avoid burned over areas. The reduction in
densities of small mammals such as rodents can adversely affect the food
supply for small carnivores.
Fires also destroy leaf litter and its associated arthropod community,
further reducing food availability for omnivores and carnivores
(Kinnaird and O'Brien, 1998).

--> Fire-adapted fauna
Not all species suffer from fire. For instance, grass-layer beetle
species in Australia's savannahs show remarkable resilience to fire,
although fires affect abundance, species and family richness (Orgeas and
Andersen, 2001).
In the fire-prone Mediterranean region, the current fire regime has
probably contributed to maintaining the bird diversity at the landscape
level in Portugal (Moreira et al., 2001). In Israel, richness of fauna
species in certain areas was the highest two to four years after a fire
followed by a decrease over time (Kutiel, 1997).
Fire can have positive effects on wildlife populations in boreal
forests, where fire is a major natural disturbance mechanism. In North
America, although moose are occasionally trapped and killed by fire,
fire generally enhances moose habitat by creating and maintaining seral
communities, and is considered beneficial to moose populations
(MacCracken and Viereck, 1990). The beneficial effects of fire on its
habitat is estimated to last less than 50 years, with moose density
peaking 20 to 25 years following fire (LeResche, Bishop and Coady,
1974).
Fire has contributed to the reduction in populations of grey wolf (Canis
lupus) in Minnesota, United States, by limiting its prey - including
beaver (Castor canadiensis), moose and deer, fire-dependent species that
require the plant communities that persist following frequent fires
(Kramp, Patton and Brady, 1983).

EFFECTS OF SUPPRESSION OF THE NATURAL FIRE REGIME
Temperate forests in the United States and Australia in which fire was
deliberately suppressed are now experiencing devastating wildfires
because of an unnatural accumulation of fuel. Deliberate human
suppression of fire can also have direct negative impacts on species. In
forests where fire is a natural part of the system, plant and animal
species are adapted to a natural fire regime and benefit from the
aftermath of a fire.
In North America, fire suppression in some areas has contributed to
decline in the numbers of grizzly bear, Ursus arctos horribilis
(Contreras and Evans, 1986). Fires promote and maintain many important
berry-producing shrubs, which are an important food source for bears, as
well as providing habitat for insects and in some cases carrion. The
1998 fires in Yellowstone National Park increased availability of some
food items for grizzly bears, especially carcasses of elk (Blanchard and
Knight, 1990).
In boreal forests, exclusion of fire induces the build-up of organic
layers that prevents melting of the upper soil during spring and summer
and rise of the permafrost layer, resulting in impoverishment of
forests, decrease in productivity and conversion of forests to marshes.

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REFERENCES
Agee, J.K. 1993. Fire ecology of Pacific Northwest forests. Washington,
DC, USA, Island Press.
Andrew, N., Rodgerson, L. & York, A. 2000. Frequent fuel-reduction
burning: the role of logs and associated leaf litter in the conservation
of ant biodiversity. Austral Ecology, 25(1): 99-107.
Blanchard, B.M. & Knight, R.R. 1990. Reactions of grizzly bears, Ursus
arctos horribilis, to wildfire in Yellowstone National Park, Wyoming.
Canadian Field Naturalist, 104(4): 592-594.
Boer, C. 1989. Effects of the forest fire 1982-83 in East Kalimantan on
wildlife. FR Report No. 7. Samardinda, Indonesia, Deutsche Forstservice
GmbH.
Cochrane, M.A., Alencar, A., Schulze, M.D., Souza, C.M., Nepstad, D.C.,
Lefebvre, P. & Davidson, E.A. 1999. Positive feedbacks in the fire
dynamic of closed canopy tropical forests. Science, 284: 1834-1836.
Contreras, G.P. & Evans, K.E. 1986. Proceedings - grizzly bear habitat
symposium. General Technical Report INT-207. Ogden Utah, USA, United
States Department of Agriculture - Forest Service, Intermountain
Research Station.
Davies, S.J. & Unam, L. 1999. Smoke-haze from the 1997 Indonesian forest
fires: effects on pollution levels, local climate, atmospheric CO2
concentrations, and tree photosynthesis. Forest Ecology and Management,
124: 137-144.
Dennis, R., Meijaard, E., Applegate, G., Nasi, R. & Moore, P. 2001.
Impact of human-caused fires on biodiversity and ecosystem functioning,
and their causes in tropical, temperate and boreal forest biomes. CBD
Technical Series No. 5. Montreal, Canada, Convention on Biological
Diversity.
FAO. 2001. The Global Forest Resources Assessment 2000 - main report.
FAO Forestry Paper No. 140. Rome, FAO.
International Union for the Conservation of Nature - World Conservation
Union (IUCN) and World Wide Fund for Nature (WWF). 2000. Global review
of forest fires. Gland, Switzerland.
Johnson, E.A. 1992. Fire and vegetation dynamics - studies from the
North American boreal forest, Cambridge, UK, Cambridge University Press.
Kinnaird, M.F. & O'Brien, T.G. 1998. Ecological effects of wildfire on
lowland rainforest in Sumatra. Conservation Biology, 12(5): 954-956.
Kramp, B.A., Patton, D.R. & Brady, W.W. 1983. The effects of fire on
wildlife habitat and species. RUN WILD: wildlife/habitat relationships.
United States Department of Agriculture - Forest Service, Southwestern
Region.
Kutiel, P. 1997. Spatial and temporal heterogeneity of species diversity
in a Mediterranean ecosystem following fire. International Journal of
Wildland Fire, 7(4): 307-315.
LeResche, R.E., Bishop, R.H. & Coady, J.W. 1974. Distribution and
habitats of moose in Alaska. Le Naturaliste Canadien, 101: 143-178.
MacCracken, J.G. & Viereck, L.A. 1990. Browse regrowth and use by moose
after fire in interior Alaska. Northwest Science, 64(1): 11-18.
Moreira, F., Ferreira, P.G., Rego, F.C. & Bunting, S. 2001. Landscape
changes and breeding bird assemblages in northwestern Portugal: the role
of fire. Landscape Ecology, 16(2): 175-187.
Nepstad, D.C., Moreira, A.G. & Alencar, A.A. 1999. Flames in the rain
forest: origins, impacts and alternatives to Amazonian fires. Brasilia,
Brazil, Pilot Program to Conserve the Brazilian Rain Forest.
Ohlson, M., Söderström, L., Hörnberg, G., Zackrisson, O. & Hermansson,
J. 1997. Habitat qualities versus long-term continuity as determinants
of biodiversity in boreal old-growth swamp forests. Biological
Conservation, 81: 221-231.
Orgeas, J.A. & Andersen, A.N. 2001. Fire and biodiversity: responses of
grass-layer beetles to experimental fire regimes in an Australian
tropical savanna. Journal of Applied Ecology, 38(1): 49-62.
Schindele, W., Thoma, W. & Panzer, K. 1989. Investigation of the steps
needed to rehabilitate the areas of East Kalimantan seriously affected
by fire. In The forest fire 1982/83 in East Kalimantan. Part I: The
fire, the effects, the damage and the technical solutions. FR Report No.
5. Jakarta, Indonesia, German Agency for Technical Cooperation (GTZ) and
International Tropical Timber Organization (ITTO).
Shvidenko, A. & Goldammer, J.G. 2001. Fire Situation in Russia.
International Forest Fire News, 24: 41-59.
Stocker, G.C. 1981. The regeneration of a north Queensland rainforest
following felling and burning. Biotropica, 13: 86-92.
Trabaud, L. & Lepart, J. 1980. Diversity and stability in garrigue
ecosystems after fire. Vegetatio, 43: 49-57.
Turvey, N.D. 1994. Afforestation and rehabilitation of Imperata
grasslands in Southeast Asia: identification of priorities for research,
education, training and extension. Canberra, Australia, Australian
Centre for International Agricultural Research (ACIAR) and Center for
International Forestry Research (CIFOR).
van Nieuwstadt, M.G.L., Sheil, D. & Kartawinata, K. 2001. The ecological
consequences of logging in the burnt forests of East Kalimantan,
Indonesia. Conservation Biology, 15(4): 1183-1186.
van Wagner, C.E. 1978. Age-class distribution and the forest fire cycle.
Canadian Journal of Forest Research, 8: 220-227.
Woods, P. 1989. Effects of logging, drought and fire on structure and
composition of tropical forests in Sabah, Malaysia. Biotropica, 21(4):
290-298.
Zackrisson, O. 1977. Influence of forest fires on the North Swedish
boreal forest. Oikos, 29: 22-32.

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ORIGINAL SOURCE
This article was reprinted with the kind permission of the publisher
from:
Nasi, R., R. Dennis, E. Meijaard, G. Applegate and P. Moore. 2002.
Forest fire and biological diversity. Unasylva 209, Vol. 53- 2002/2.
FAO, Rome. url: <http://www.fao.org////docrep/004/y3582e/y3582e08.htm#h>

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ABOUT THE AUTHORS
Robert Nasi and Grahame Applegate are on the staff of the Center for
International Forestry Research (CIFOR), Bogor, Indonesia.
Rona Dennis and Erik Meijaard are consultants for CIFOR.
Peter Moore is the coordinator of the World Wide Fund for Nature (WWF)
and World Conservation Union (IUCN) Project FireFight South-East Asia,
Bogor, Indonesia.

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WEB LINKS
Global Fire Monitoring Center (GFMC): <http://www.fire.uni-freiburg.de/>
Australian National Botanic Gardens' "Fires, gardens and fire retardant
plants - a bibliography":
<http://www.anbg.gov.au/bibliography/fire-plants.html>
University of Florida Cooperative Extension's "Protecting Your Home from
Forest Fire": <http://www.sfrc.ufl.edu/Extension/firehome.htm>

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RELATED EDITIONS OF THE OVERSTORY
The Overstory #151--Risk Management for Farm Forestry
The Overstory #138--Tree Defences
The Overstory #132--How Trees Survive
The Overstory #124--Fire
The Overstory #73--Buffers: Common Sense Conservation
<http://www.agroforestry.net/overstory/overstory73.html>
The Overstory #38--Live Fences
<http://www.agroforestry.net/overstory/overstory38.html>
The Overstory #32--Multipurpose Windbreaks
<http://www.agroforestry.net/overstory/overstory32.html>

::::::::::::::
PUBLISHER NOTES

The Overstory Book, 2nd Edition, a formatted, indexed and illustrated
compilation of The Overstory ejournal editions 1 - 138 is in stock.
Your purchase helps support publication of The Overstory:
http://www.agroforestry.net/overstory/ovbook.html
ADDRESS CHANGES: Please send any changes in your e-mail address to
overstory AT agroforestry.net

::::::::::::::


Publisher: Permanent Agriculture Resources
Editor: Craig R. Elevitch
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Address: P.O. Box 428, Holualoa, Hawaii 96725 USA
Email: overstory AT agroforestry.net ; Web site:
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This publication is Copyright 2005 Permanent Agriculture Resources.
All Rights Reserved Worldwide. For Conditions of Use please contact
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This journal is designed to provide agricultural information, but
is sent with the understanding that the editors and publishers are
not engaged in rendering consultation. If expert assistance is
required, the services of a professional should be sought.

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