As images of devastation and people running to flee wildfires in
Greece have filled newspapers in recent weeks, it is hard to regard
fire as anything but an enemy of the forest. But with the onset of
autumn - the season during which Beijing is on highest alert for
fire prevention - reserve managers of the Songshan National Nature
Reserve in northwestern Beijing are learning to treat fire as a
natural and useful tool for biodiversity conservation.
"Fire plays a vital role in maintaining many ecosystems and the
communities that depend on them," says Ron Myers, of the Global
Fire Initiative from The Nature Conservancy (TNC), a US-based
environmental organization that has been working in China for
nearly a decade. Myers and his colleagues are helping Chinese
forestry workers keep pace with internationally accepted ideas in
the field of fire management.
Integrated fire management is not exactly a new concept. In
fact, large swaths of forests in countries such as Indonesia,
Brazil and the United States have been ravished by flames, and
subsequently, these areas' biodiversity has completely
recovered.
Ever since inhabitants of the savannahs of Africa used fire to
manipulate vegetation and wildlife millions of years ago, the fate
of fire and humankind has been inextricably linked.
It wasn't until the 20th century that fire was widely viewed as
a major threat to natural resources. During this time, the natural
roles fire plays in ecosystems were forgotten. So, today, there's a
great gap in common understanding when it comes to this natural
process.
Throughout China's recent history, prevention and suppression
were taught as the predominant modes of "fire management" in
forestry academy courses.
Concepts of using forest fires to ensure biodiversity
conservation have been largely absent in Chinese forestry.
At a meeting with Chinese forestry officials, fire experts
presented a world map used in forest fire research on which regions
of the world are classified according their specific fire regimes.
China appears on the map as one of only a handful of blank
patches.
Myers is director of a TNC fire management project that annually
ignites more than 700 planned fires in the United States, using
fire to rejuvenate about 40,000 hectares of forest a year.
"Actually, a great number of species and ecosystems rely on a
cycle of fires as an essential process for conserving
biodiversity," says Myers. These can be referred to as
"fire-dependent" ecosystems. "The services fire provides to these
ecosystems include clearing space for vegetation succession,
enriching soils, cleaning water and even fertilizing seeds,
comprising a key component in ecological processes."
Some species require the high temperatures generated by fire to
germinate; in conditions where fire is restricted, these species
can very easily disappear. According to Myers, half of the
ecosystems in the world are dependent on fire to maintain native
species, habitats and landscapes.
There are also ecosystems sensitive to fires, such as many
tropical forests, where vegetation lacks the ability to survive
fire, and the impacts of fire in these forests can be severe. In
this way, fire is said to have "two faces" - fire that benefits
ecosystems or fire that harms them, depending on circumstances.
Increasingly, fires are being found to be useful, and the number
of such case studies is growing.
After decades of a strict fire-suppression policy, the United
States began allowing some carefully controlled forest fires to
burn in the 1960s. Many semi-arid grazing lands in the United
States are now burned annually in order to control invasive grass
species. Regular controlled fires also keep vegetation from growing
too dense, which prevents the devastating large-scale, intense and
uncontrollable fires that result from long periods of fire
suppression.
But the use of controlled fires is far from simple. In planning
controlled burns, experts must control both the type and duration
of the fire, in addition to spacing, intensity, wind impact, impact
on soils, flame direction and emergency-suppression capabilities,
among other concerns.
A typical pine forest fire regime, for example, involves
frequent ground fires that clear underbrush without reaching the
tree canopy, allowing for seed germination. A controlled burn in
this type of system must suit such conditions. Otherwise, a canopy
fire could result in great losses to the forest.
Post-fire actions are also important in the process. Another
fire management specialist with the team, Darren Johnson, says that
a "scientific, post-fire recovery design is needed to effectively
achieve controlled burning conservation goals".
"Such a plan considers the ecology of the burned area, including
species' recovery potential and a careful analysis of habitat
changes," he says.
While at Songshan, the TNC team carried out an initial survey of
Chinese pine forests. They noticed a lack of natural regeneration
and considered which factors were inhibiting this regeneration.
Most pine forests around the world are dependent on fire for
propagation, while some pine forest ecosystems have also been shown
to require other forms of disturbance for propagation, such as
logging, rock and mud slides, and other forms of clearing by
humans. As in most nature reserves in China, forest fires are
strictly suppressed at Songshan.
Through consultations with Songshan staff and community members,
the team gained a better understanding of the relationship between
the current distribution of Chinese pines and of the historic cases
of fire in the forest.
During the discussions, Johnson asked the forestry officials if
they had ever considered using fire as a means of improving
conditions where pines were regenerating poorly. Zhou Junliang, an
official with the State Forestry Administration (SFA), explains
that China currently does not use forest fire as a means of
biodiversity conservation.
He recalls a few nature reserves in the past applying for
permission to use fire in opening up habitat and food sources for
wildlife.
But he emphasizes that nature reserves in China are under strict
management, especially in the control of forest fires. The SFA once
issued regulations allowing for planned burns around the fringes of
forests to prevent fires from entering, but because of fears that
these fires would burn out of control, the regulations were never
acted upon.
"Even though this type of problem exists throughout China, there
is a lack of regulations that correspond to these changing
mindsets, leaving officials incapable of implementing some key
measures," Zhou says.
The authors work for the TNC Beijing Office
(China Daily September 24, 2007)
