title: Vietnam's forest transition in retrospect: demonstrating weaknesses in business-as-usual scenarios for REDD.
abstract: One of the prerequisites of the REDD+ mechanism is to effectively predict business-as-usual (BAU) scenarios for change in forest cover. This would enable estimation of how much carbon emission a project could potentially prevent and thus how much carbon credit should be rewarded. However, different factors like forest degradation and the lack of linearity in forest cover transitions challenge the accuracy of such scenarios. Here we predict and validate such BAU scenarios retrospectively based on forest cover changes at village and district level in North Central Vietnam. With the government's efforts to increase the forest cover, land use policies led to gradual abandonment of shifting cultivation since the 1990s. We analyzed Landsat images from 1973, 1989, 1998, 2000, and 2011 and found that the policies in the areas studied did lead to increased forest cover after a long period of decline, but that this increase could mainly be attributed to an increase in open forest and shrub areas. We compared Landsat classifications with participatory maps of land cover/use in 1998 and 2012 that indicated more forest degradation than was captured by the Landsat analysis. The BAU scenarios were heavily dependent on which years were chosen for the reference period. This suggests that hypothetical REDD+ activities in the past, when based on the remote sensing data available at that time, would have been unable to correctly estimate changes in carbon stocks and thus produce relevant BAU scenarios.
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, 1350, Copenhagen K, Denmark.
authors.forename: Jeppe
authors.initials: J
authors.lastname: Ankersen
authors.forename: Kenneth
authors.initials: K
authors.lastname: Grogan
authors.forename: Ole
authors.initials: O
authors.lastname: Mertz
authors.forename: Rasmus
authors.initials: R
authors.lastname: Fensholt
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Castella
authors.forename: Guillaume
authors.initials: G
authors.lastname: Lestrelin
authors.forename: Dinh Tien
authors.initials: DT
authors.lastname: Nguyen
authors.forename: Finn
authors.initials: F
authors.lastname: Danielsen
authors.forename: Søren
authors.initials: S
authors.lastname: Brofeldt
authors.forename: Kjeld
authors.initials: K
authors.lastname: Rasmussen
mesh_terms: D002244:Carbon / Q000032:analysis; D003132:Commerce; D003247:Conservation of Natural Resources / Q000379:methods* / Q000639:trends*; D058735:Environmental Policy / Q000191:economics / Q000639:trends*; D065928:Forests; D014744:Vietnam
chemical_list: D002244:Carbon