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)