Here’s the illuminating quote about secondary forests on page 5 of State of the World’s Forests 2005, from the UN Food and Agriculture Association (FAO):

Areas of secondary forest throughout the

tropics are increasing dramatically, and in many

tropical countries they now exceed areas covered

by primary forest. Most of these secondary

forests develop following the disturbance or

elimination of natural forests by slash-and-burn

practices, conversion to agricultural activities and

subsequent abandonment of lands or following

excessive logging operations that have reduced

the original forest to a non-commercial resource.

In both cases, seeds from surrounding trees have

led to eventual regeneration of the forest.

Although figures vary according to the

definition used, the extent of degraded forests

and secondary forests in tropical Africa,

America and Asia in 2002 was estimated at 245

million, 335 million and 270 million hectares,

respectively, for a total 850 million hectares

(ITTO, 2002). According to FAO (2001), the

reported loss of natural forests in the tropics

during the 1990s was approximately 15.2

million hectares annually, of which 90 percent

or more was converted to other land uses. These

estimates indicate that the potential future area

of secondary forests could be considerable.

That 850 million hectares of secondary and degraded tropical forest translates to 2.1 billion acres or 3.3 million square miles.

The 15.2 million hectares of primary tropical forest lost annually equals 37.3 million acres or 58,300 square miles.

The ratio is 55 to 1.  For every acre of primary tropical forest being cleared, logged, or burned, some 55 acres of secondary tropical forest is growing back or can be nurtured back.  How climate change is affecting those numbers remains to be seen.

The two citations are:

ITTO (International Tropical Timber Organization).

2002. ITTO guidelines for the restoration, management

and rehabilitation of degraded and secondary forests.

ITTO Policy Development Series No. 13. Yokohama,


page 5:

The extent of forest degradation in the tropics is vast. According to estimates given in these

guidelines, some 350 million hectares of tropical forest land have been so severely damaged that

forests won’t grow back spontaneously, while a further 500 million hectares have forest cover that is

either degraded or has regrown after initial deforestation.

Such large areas of damaged forest and land are cause for concern, but they also represent a potential

resource of immense value. The ITTO guidelines for the restoration, management and rehabilitation of

degraded and secondary forests have been formulated to help communities realize that potential.

FAO. 2001. Global Forest Resources Assessment

2000 – Main report. FAO Forestry Paper No. 140.


While the FAO’s State of the World’s Forests 2005 emphasized secondary forests, the latest edition—State of the World’s Forests 2009—mentions secondary forests not at all.