Low-Impact Logging

In recent years there has been renewed interest in the concept of low-impact logging and the sustainable management of forests. The idea is to harvest timber in such a way that doing so inflicts minimal damage on the forest and its wildlife. The forest gradually recovers, permitting another harvest a few decades later. Faced with pressure from conservationists, some traders now advertise their timber as originating from forests that have been certified as being sustainably managed. Let’s take a look at how low-impact logging works.

A professional forester and a group of assistants push their way through the undergrowth. They form one of several groups that will spend perhaps six months in the jungle, conducting a forest inventory. The logging company has a long-term concession here, so the workers have the time to take this tree census for the sake of preserving the forest for future use.

The forester marks each tree with a registration number and identifies the species. There are hundreds of varieties, so he must have considerable expertise. The next step, however, requires modern technology.

Using a hand-held device that communicates with satellites of the Global Positioning System, the forester keys in the tree’s size, species, and registration number. Then when he hits the enter button, all the details of that tree, including its exact position, are instantly sent from the forest to a computer in a bustling city far away.

Later the forest manager has his computer print out a map detailing every tree of value in the forest. He chooses precisely which trees may be felled in harmony with official regulations. In the case of many species, it is permissible to fell only 50 percent of the trees larger than a certain diameter specified in the concession. The oldest and healthiest trees must be left standing as seed bearers.

How, though, can you fell trees without damaging the forest? Awake! put that question to Roberto, the forester mentioned in the preceding article. He explained: “The map is the key. With the tree map, we can plan the harvest so as to cause minimum damage to the forest. Even the direction of felling can be planned to minimize collateral damage.

“We can also plan the extraction of logs with winches, instead of using bulldozers to break through to every tree felled. Before felling, loggers cut the vines that connect crop trees to their neighbors​—again to reduce collateral damage. We work the concession in rotation, each year mapping and harvesting a section so that we will not return to plots until at least 20 years have passed. For some forest areas, it’s 30 years.”

However, Roberto is employed by a logging company. Awake! thus asked him: “How much interest do loggers really have in protecting wildlife?”

Protecting the Animals

“You can’t have a healthy forest without animals,” Roberto notes. “They are vital for the pollination and dispersal of seeds. We make every effort to reduce the disturbance to wild animals. For example, we carefully plan access roads so that they are few and far between. Wherever possible, we make roads narrow enough to permit the tree canopy to close over them. This allows animals such as sloths and monkeys to cross the road without descending from the trees.”

Roberto points to some colored areas on his map. These are to be left completely untouched. A protected corridor on each side of every stream, for example, permits animals to move from one area to another in undisturbed jungle.

“Besides the vital streamside habitats,” he explains, “we also protect caves, outcrops of rock, ancient trees with cavities, trees bearing fleshy fruits​—in fact, any area vital to the survival of a certain species. To prevent illegal hunting, we forbid our employees to have guns, and so that they won’t need wild meat, we fly beef and chicken into the lumber camp. Then, when we have finished a section, we carefully block or control the roads to prevent hunters or illegal loggers from entering the forest.

“Personally, I’m happy to do all this because I believe in conserving God’s creation. But nearly all the measures I’ve described are required by international regulations for a certified, sustainably managed forest. To get a certificate, a company has to satisfy inspectors from international organizations.”

Are sustainably managed forests profitable? Aside from a few enthusiasts like Roberto, loggers as a rule do not receive plans to conserve wildlife with much enthusiasm. Such restrictions are often perceived as a threat to profit.

Nevertheless, studies carried out in eastern Amazonia in the late 1990’s found that the cost of tree mapping, vine cutting, and planned log extraction was more than recovered, thanks to the increased efficiency achieved. Fewer logs were lost, for example. Often, without such mapping, a chain-saw crew will fell a tree that the extraction crew cannot find in the dense jungle.

Also, timber independently certified as originating from a sustainably managed forest may be easier to sell. But does low-impact logging really protect biodiversity? How much wildlife survives such a rain-forest harvest?

Can Forest Wildlife Survive Logging?

Granted, tropical rain-forest ecosystems are fragile and complex. Yet, they can prove surprisingly resilient under certain conditions. For example, if some untouched forest remains near a harvested area, saplings of the harvested species will gradually grow to fill the gaps left in the canopy. But what about the animals, birds, and insects?

A few species are affected seriously, and most logging operations reduce the number of bird and animal varieties in the area. However, low-impact logging often has very little effect on the majority of species. In fact, the opening of gaps in the canopy may actually encourage some species. Recent research has suggested that the presence of humans​—even when some of them are there for selective logging—​may increase the biological diversity of rain forests.

There is considerable evidence, then, to suggest that tropical rain forests can be harvested responsibly, without doing permanent damage to the diversity of life. London’s Economist said: “Just 10% of the remaining forest, managed sustainably, could meet all the existing demand for tropical hardwood. Much of the rest might then be declared untouchable.”

[Maps on page 7]

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BOLIVIA

The map at right gives details about each tree; as the above shows, the map represents only a tiny region of Bolivia

[Credit Line]

All maps except top left: Aserradero San Martin S.R.L., Bolivia

[Pictures on page 7]

Each tree is individually numbered, and its species identified. Then, with the help of a Global Positioning System monitor (above), its exact location is recorded

[Picture on page 7]

‘The forest inventory map is the key to planning a forest harvest that will not permanently damage the forest or its wildlife.’​—Roberto