Tartagal Site of the study
The city of Tartagal is located at the base of the Argentinean sub-Andean hills (22◦32-S, 63◦49-W, 450m above sea level) at 450m above sea level, in the Salta province (Fig. 1).
The city is distant of 365 km from the city of Salta, capital of the province, and of 55 km from the Bolivian border. Tartagal’s urban area covers approximately 15 km2, with 60585 inhabitants, including several ethnic groups such as native Amerindians (Instituto Nacional de Estad´ıstica y Censos, 2001).
The city is surrounded by subtropical native forests and crops such as, beans, cotton, soybean, maize, grapefruit and tomato. The climate is subtropical, with annual rainfalls of about 1000 mm, means temperatures of about 23◦ C in spring, 38◦ C in summer, 14◦ C in autumn and 9◦ C in winter, with more than 350 days free of frost annually.
