Antonio Lara,Christian Little,Rocio Urrutia,James McPhee,Camila Alvarez, Universidad Austral de Chile, Instituto de Silvicultura, antoniolara@uach.cl
Native forests of the Valdivian Rainforest Eco-region in Chile (35º-48º S), are among those with the highest conservation priority worldwide and provide important ecosystem services. This study quantifies water supply as an ecosystem service from native forests. Monitoring of six watersheds between 2003 and 2006 showed that the annual runoff coefficient (quickflow/precipitation, Qq/P) and total streamflow/summer precipitation were significantly correlated with native forest cover in the watershed (R2 =0.67 and 0.76, respectively, P<0.05). Conversely, the annual runoff coefficient was negatively correlated with the exotic plantation cover (R2 =0.59, P=0.072). Comparison of 2003-2006 streamflow between a watershed with thinned native forest and a control paired watershed, showed that the thinned forest had 19.7% and 40% greater annual and summer streamflow, respectively. These studies demonstrate one of the significant impacts land use change has on streamflow and provides crucial information on the potential use of native forest cover to conserve or increase streamflow in Chile and elsewhere.
Keywords: Land use change, Ecological restoration, Forest policy