Facing the challenge of the Andean Zone: the role of modeling in developing sustainable management of natural resources

Estimates of sub-national nutrient balances as sustainability indicators for agro-ecosystems in Ecuador

“…Erosion is an important factor in a negative nutrient balance as it was also in the previous studies by Stoorvogel et al (1993) and . This is in line with Quiroz et al (1995) who used the EPIC model to estimate soil loss through erosion in Peru and stated that "current management of most cultivable land in the Andes threatens the sustainability of the agricultural systems and thus jeopardises the future of the region's inhabitants, because of excessive soil erosion". Our results suggest that not only in the Andes, but also in the coastal zone and the Amazon, serious threats occur due to erosion and leaching.…”

“…As a test case, Ecuador was selected, a country with a high agro-ecological diversity, that is characterised by an increasing pressure on land use, overexploitation of natural resources, low productivity and threats to biodiversity (Quiroz et al, 1995).…”