Global forest cover has been reduced by at least 20 percent since preagricultural times, possibly by 50 percent. Forest area has increased slightly since 1980 in industrial countries, but has declined by at least 10 percent in developing countries. Tropical deforestation rates are uncertain, but probably exceed 130,000 km2 per year. About 40 percent of forests are relatively undisturbed by human activity, though nearly half of these are likely to be developed soon. Nearly all forests in Europe and the United States are under some degree of management.
Roads are a useful proxy indicator of habitat fragmentation and degradation.
The world's expanding road network is opening up remote forests to logging, mining, and pioneer settlement. Roads also increase hunting and poaching. The area burned by natural forest fires is now insignificant in comparison with human-initiated fires. Tropical forest fires have increased in area and intensity in recent years, because of drought, clearance for agriculture, and land tenure disputes. Information status and needs National level forest maps are often outdated and forest inventories unreliable in developing countries.