A vulnerability analysis of the temperate forests of south central Chile Kerrie Wilson a,b,*, Adrian Newton c, Cristian Echeverr��a �� d, Chris Weston b, Mark Burgman e a The Ecology Centre, University of Queensland, Brisbane, Qld. 4072, Australia b School of Forestry, University of Melbourne, Melbourne, Vic. 3010, Australia c School of Conservation Sciences, Bournemouth University, Talbot Campus, Poole, Dorset BH12 5BB, UK d Facultad de Ciencias Forestales, Universidad Austral de Chile, Casilla 567, Valdivia, Chile e School of Botany, University of Melbourne, Melbourne, Vic. 3010, Australia Received 11 September 2003 received in revised form 2 June 2004 accepted 7 June 2004 Abstract Areas of the landscape that are priorities for conservation should be those that are both vulnerable to threatening processes and that if lost or degraded, will result in conservation targets being compromised. While much attention is directed towards understand- ing the patterns of biodiversity, much less is given to determining the areas of the landscape most vulnerable to threats. We assessed the relative vulnerability of remaining areas of native forest to conversion to plantations in the ecologically significant temperate rainforest region of south central Chile. The area of the study region is 4.2 million ha and the extent of plantations is approximately 200000 ha. First, the spatial distribution of native forest conversion to plantations was determined. The variables related to the spa- tial distribution of this threatening process were identified through the development of a classification tree and the generation of a multivariate, spatially explicit, statistical model. The model of native forest conversion explained 43% of the deviance and the dis- crimination ability of the model was high. Predictions were made of where native forest conversion is likely to occur in the future. Due to patterns of climate, topography, soils and proximity to infrastructure and towns, remaining forest areas differ in their relative risk of being converted to plantations. Another factor that may increase the vulnerability of remaining native forest in a subset of the study region is the proposed construction of a highway. We found that 90% of the area of existing plantations within this region is within 2.5 km of roads. When the predictions of native forest conversion were recalculated accounting for the construction of this highway, it was found that approximately 27000 ha of native forest had an increased probability of conversion. The areas of native forest identified to be vulnerable to conversion are outside of the existing reserve network. �� 2004 Elsevier Ltd. All rights reserved. Keywords: Chile Classification and regression trees Conservation planning Logistic regression Vulnerability 1. Introduction The cool temperate rainforest region of Chile (be- tween 36.5�� and 54�� south) represents the second larg- est remaining area of this forest type in the world (Wilcox, 1995) and is internationally recognised for its ecological importance (Davis et al., 1994���1997 Ol- son and Dinerstein, 1998 Stattersfield et al., 1998). These forests are isolated by physical and climatic bar- riers, resulting in high endemism in plants and animals: 28 of 82 genera of woody plants (34%) are endemic to the region, along with 50% of vines, 53% of hemipara- sites (Arroyo et al., 1993, 1996b), and 45% of verte- brates (Armesto et al., 1996). Despite the ecological importance of these forests, they have experienced a long history of destruction and are presently threatened with the conversion to other land uses, particularly plantations of exotic species. 0006-3207/$ - see front matter �� 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.biocon.2004.06.015 * Corresponding author. Tel.: +61-0-7-3701-5899 fax: +61-0-7- 3365-1655. E-mail address: k.wilson2@uq.edu.au (K. Wilson). www.elsevier.com/locate/biocon Biological Conservation 122 (2005) 9���21 BIOLOGICAL CONSERVATION

Large-scale destruction of Chile��s temperate forest commenced with the Spanish invasion in the 16th century, during which time there was conflict between the indig- enous peoples of Chile (the Mapuches) and the Spanish. The Spanish reportedly burned vast expanses of native forest to prevent the Mapuches taking refuge (CO- DEFF, 1992). When Chile gained independence from Spain, the Chilean government promoted the immigra- tion of European colonists. Commercial exploitation of the forests began with the arrival of these colonists between 1860 and 1900, which entailed massive clearing and burning of the forests of the Central Valley and adjacent foothills for cropland and pasture (Rozzi et al., 2000). This period of colonisation resulted in one of the most rapid deforestation events to be recorded in Latin America (Veblen, 1983). During the latter half of the 20th century, one of the main causes of deforestation in south central Chile has been the conversion of native forests to plantations of exotic species, mainly Monterey pine (Pinus radiata) and Eucalypt species (Eucalyptus globulus and Eucalyp- tus nitens). This was largely initiated after the 1973 mil- itary coup against Salvador Allende��s government by Augusto Pinochet, when a market economy was imple- mented that significantly reduced the direct involvement of the public sector in the economy (Lara and Veblen, 1993). This enabled the country��s forestry properties to be sold at artificially depressed prices to private indus- try. Other incentives to private plantations were imple- mented with the promulgation of Decree Law 701 in 1974 (Ministerio de Agricultura, 1974, 1979), which in- cluded direct subsidies for plantations (75% of the cost) and tax exemptions. Subsidies for administrative and maintenance costs (for example, fencing) began in 1978 and pruning grants for plantations were introduced in 1983. The availability of a cheap workforce was guar- anteed through the prohibition of union activity and the use of contract labour (Carrere and Lohmann, 1996). In addition, the government introduced a series of tax cred- its encouraging the exportation of forest products. In 2000, the forest industry accounted for more than 10% of all Chilean exports (Neira et al., 2002). Presently, one of the greatest threats facing the temper- ate rainforests of Chile is the conversion to plantations of exotic species (Neira et al., 2002). The proposed construc- tionofahighwayinthecoastalrangeofthisregionislikely to facilitate further access to these forests. Despite these threats, coastal temperate rainforests are the least repre- sented in the reserve network (Neira et al., 2002), which is biased towards the high elevation, volcanic areas of the Andes (Armesto et al., 1998). Strategies are sought to reduce the impacts of the con- version of native forest to plantations within the temper- ate forest region of south central Chile. One promising strategy is to assess the vulnerability of the remaining ar- eas of native forest to help identify their relative urgency for protection and aid the process of prioritisation during implementation of new conservation areas (Margules and Pressey, 2000 Wilson et al. submitted). Here, we describe an assessment of the relative vul- nerability of remaining areas of native forest to conver- sion to plantations. The probability of exposure of native forest to this threatening process is assessed using a quantitative method based on spatial and statistical modelling. The method involves determining the extent and spatial distribution of native forest conversion to plantations and the factors that have predisposed areas to conversion. First, a classification tree is used to iden- tify explanatory variables that may explain the spatial distribution of native forest conversion. These variables are then further analysed using a multivariate, logistic regression model. The variables most closely associated with the location of native forest conversion are empir- ically determined. Finally, areas of native forest with a high probability of conversion are identified in order to delineate highly vulnerable areas of native forest. The distribution of vulnerable areas of native forest is then compared to the location of existing protected areas. This vulnerability assessment provides information that will assist in identifying areas that are the priorities for conservation within the study region. 2. Methods 2.1. Study region The study region within south central Chile extends from approximately latitude 39.5�� south to 43�� south (Valdivia, Osorno, and Llanquihue Provinces of Region X), and extends from the coastal mountain range to the Andes (Fig. 1). The study region covers approximately 4.2 million ha. This region contains a large proportion of the remaining temperate forest in southern Chile and is presently experiencing high rates of conversion to plantations. Approximately 53% (two million hec- tares) of the native forest that was estimated to be pre- sent in this region prior to European settlement remains. About 200000 ha of native forest have been converted to plantations and much of the remainder has been converted to pastoral and agricultural land uses. Temperate forest is now largely restricted to the upper elevations of the Andean mountain range and the coastal range. Before European settlement, extensive forests existed in the Central Valley between the two mountain ranges. 2.2. Analysis procedure 2.2.1. Step 1: Obtain land cover datasets Two land cover datasets were used in the analysis: the most recent land cover dataset that has been obtained 10 K. Wilson et al. / Biological Conservation 122 (2005) 9���21