SciDev.Net

Dry tropical forest, Madagascar

2007 Elmqvist et al.

Forests are spontaneously regenerating in Madagascar, even in densely populated areas, according to a study published in PLoS ONE this week (2 May).

The study highlights the importance of understanding social issues in forest management.

Madagascar's dry forest has been reported as in decline since the 1970s, due to clearing for agriculture and cattle farming, timber and charcoal.

Scientists analysed satellite images of the southern Androy region of Madagascar ― an area of 5,500 square kilometres ― from 1984, 1993 and 2000.

But they were surprised to find net forest regrowth of four per cent from 1993 to 2000.

The researchers write that this shows the "large capacity of a semi-arid system to spontaneously regenerate, triggered by decreased pressures".

They say this supports prior research suggesting that pressures on Madagascan forests may have been overstated. 

"We were surprised to find the highest deforestation rates in an area with low human population density and large distance to markets, while the area with highest population density had stable forest cover," said lead author Thomas Elmqvist, of the Stockholm Resilience Centre in Sweden.

From interviews with forest officials and local residents, the researchers discovered that forest loss often occurred in areas with insecure property rights.

Areas with well-defined property rights, forestry management regulations and local norms for practices such as livestock grazing showed either regenerating ― where there was a low population density ― or stable forest cover.

Stable property rights for villagers and guaranteed stakes in forest management could help the regeneration of dry tropical forests on the island, the research concludes.

Maria Tengö, an author on the study from Stockholm University, said that although a fair amount is known about how humans cause the loss of tropical forests, "very little is known about the role of social institutions in influencing regeneration of tropical forests".

The authors say their results fill a gap in our knowledge of how to repair forests that are under intense pressure from human development.

Link to full article/paper in PLoS ONE

Reference: PLoS One doi 10.1371/journal.pone.0000402.g006 (2007)