If stated often enough, a fact becomes truth. That seems to be the case with the oft-repeated figure that “Madagascar has lost 90% of its original forest cover”. The problem, as Bill McConnell of Michigan State University and I point out in a letter just published in Science magazine, is that this fact cannot be proven.
We build our detailed case in a chapter in the new book Conservation and Environmental Management in Madagascar, edited by Ivan Scales. We outline the history of efforts to measure forest extent and its loss on the island of Madagascar. We show how the 90% figure (and its close relatives) is not based on defensible evidence. And we argue that this figure persists, despite the lack of evidence, because it has power: it fits with certain preconceived ideas about the gravity of the island’s environmental crisis.
Deforestation trends are dramatic enough in some parts of the island that there is no need to exaggerate. These exaggerations are even potentially harmful in that they can undermine scientific authority, put blinders on the types of questions that are asked, and push to the sidelines important debates about the impacts of strong conservation policies on rural people.
Our review shows a number of things:
- That the island’s pre-human vegetation cover changed over time and contained non-forest elements like heath or grassland (rendering problematic the frequent presumption of pre-human island wide forests): there is no quantifiable ‘original’ forest before humans arrived at least two millennia ago
- That estimates of forest cover before 1949-1950 air photos are not reliable enough to use in quantitative analyses
- That efforts at forest measurement and forest change analysis using air photos and satellite images are difficult and rife with inconsistent categories and problematic re-uses of previous studies
- That a general trend of forest loss can be shown. Comparisons of data derived from historical aerial photography and recent satellite imagery appear to be converging on an estimate that as much as half – but perhaps much less – of the most easily identified ‘primary’ forest types changed to other land covers since 1949-1950.
- That regional studies demonstrate dramatic trends in particular regions for particular time periods. Harper et al. (2007), for instance, highlights the impact of clearance for maize cultivation in the dry forests around Tulear in the last few decades, or my recent work (Kull 2012) documents the extent of afforestation by pines and eucalypts in the highlands.
We also showed how over two dozen peer-reviewed studies (and countless guidebooks and websites) have repeated the 90% figure first asserted by colonial naturalist Henri Perrier de la Bâthie back in 1921. The citation trail for these assertions is surprisingly poor. Its persistence reflects the strong hold that a particular conservation-oriented mindset has on scholarly and other writing about Madagascar. Authors inevitably describe the island as both highly biodiverse and highly threatened, and the 90% figure helps them dramatize the case for conservation actions.
In their response to our letter to Science, the authors of the study we critiqued for using the 90% figure (Christoph Schwitzer and colleagues) essentially agreed with our stance. They retracted their statement that “Remaining intact forest habitat was estimated to cover 92,200 km2 in 2010, only 10 to 20% of Madagascar’s original forest cover“, changing it from a statement about forest cover change to one about surface area: “Remaining intact forest habitat was estimated to cover 92,200 km2 in 2010, only 10 to 20% of Madagascar’s surface” (emphases added). And they essentially agree with our “cautious” but still “substantial” conclusion that recent deforestation involved up to half the forest area found in 1950 – though they seek to push the upper bounds of the envelope by offering a simple comparison of statistics from studies using different methodologies (which we critique in the chapter).
The discourse of exotic nature and environmental destruction can be seen as necessary to justify conservation fundraising, policies, and actions. Yet, as Richard Peet and colleagues (2011, p. 37) state, “arguments over the apparently ‘given’ facts and categories of ecology are always also arguments over social and political control of nature”. The dominant narrative and its exaggeration of forest loss contribute to strong conservation policies and actions that marginalize rural people, restrict their access to resources, and silence their viewpoints (see other chapters in Conservation and Environmental Management in Madagascar). More careful use of data can support more appropriate debates and policy, and may help us to better avoid the further reduction of the island’s forest cover – so that, in the future, we won’t be in a position to show that 90% of tree cover documented in the mid-20th century has actually disappeared.
Harper, GJ, MK Steininger, CJ Tucker, D Juhn & F Hawkins (2007) Fifty years of deforestation and forest fragmentation in Madagascar. Environmental Conservation 34 (4):325-33.
Kull, CA (2012) Air photo evidence of historical land cover change in the highlands: wetlands and grasslands give way to crops and woodlots. Madagascar Conservation and Development 7 (3):144-152. [link]
Perrier de la Bâthie, H (1921) La végétation Malgache. Annales du Musée Colonial de Marseille Sér. 3, v. 9:1-266.
McConnell, WJ & CA Kull (2014) Deforestation in Madagascar: Debates over the island’s forest cover and challenges of measuring forest change. p.67-104 in Conservation and Environmental Management in Madagascar, ed. IR Scales. London: Routledge. pdf
Peet, R, P Robbins & M Watts (2011) Global Political Ecology. London: Routledge.